Aerosol delivery with two ventilation modes during mechanical ventilation: a randomized study.

PubMed

Dugernier, Jonathan; Reychler, Gregory; Wittebole, Xavier; Roeseler, Jean; Depoortere, Virginie; Sottiaux, Thierry; Michotte, Jean-Bernard; Vanbever, Rita; Dugernier, Thierry; Goffette, Pierre; Docquier, Marie-Agnes; Raftopoulos, Christian; Hantson, Philippe; Jamar, François; Laterre, Pierre-François

2016-12-01

Volume-controlled ventilation has been suggested to optimize lung deposition during nebulization although promoting spontaneous ventilation is targeted to avoid ventilator-induced diaphragmatic dysfunction. Comparing topographic aerosol lung deposition during volume-controlled ventilation and spontaneous ventilation in pressure support has never been performed. The aim of this study was to compare lung deposition of a radiolabeled aerosol generated with a vibrating-mesh nebulizer during invasive mechanical ventilation, with two modes: pressure support ventilation and volume-controlled ventilation. Seventeen postoperative neurosurgery patients without pulmonary disease were randomly ventilated in pressure support or volume-controlled ventilation. Diethylenetriaminepentaacetic acid labeled with technetium-99m (2 mCi/3 mL) was administrated using a vibrating-mesh nebulizer (Aerogen Solo(®), provided by Aerogen Ltd, Galway, Ireland) connected to the endotracheal tube. Pulmonary and extrapulmonary particles deposition was analyzed using planar scintigraphy. Lung deposition was 10.5 ± 3.0 and 15.1 ± 5.0 % of the nominal dose during pressure support and volume-controlled ventilation, respectively (p < 0.05). Higher endotracheal tube and tracheal deposition was observed during pressure support ventilation (27.4 ± 6.6 vs. 20.7 ± 6.0 %, p < 0.05). A similar penetration index was observed for the right (p = 0.210) and the left lung (p = 0.211) with both ventilation modes. A high intersubject variability of lung deposition was observed with both modes regarding lung doses, aerosol penetration and distribution between the right and the left lung. In the specific conditions of the study, volume-controlled ventilation was associated with higher lung deposition of nebulized particles as compared to pressure support ventilation. The clinical benefit of this effect warrants further studies. Clinical trial registration NCT01879488.

Pressure Dynamic Characteristics of Pressure Controlled Ventilation System of a Lung Simulator

PubMed Central

Shi, Yan; Ren, Shuai; Cai, Maolin; Xu, Weiqing; Deng, Qiyou

2014-01-01

Mechanical ventilation is an important life support treatment of critically ill patients, and air pressure dynamics of human lung affect ventilation treatment effects. In this paper, in order to obtain the influences of seven key parameters of mechanical ventilation system on the pressure dynamics of human lung, firstly, mechanical ventilation system was considered as a pure pneumatic system, and then its mathematical model was set up. Furthermore, to verify the mathematical model, a prototype mechanical ventilation system of a lung simulator was proposed for experimental study. Last, simulation and experimental studies on the air flow dynamic of the mechanical ventilation system were done, and then the pressure dynamic characteristics of the mechanical system were obtained. The study can be referred to in the pulmonary diagnostics, treatment, and design of various medical devices or diagnostic systems. PMID:25197318

Cost containment and mechanical ventilation in the United States.

PubMed

Cohen, I L; Booth, F V

1994-08-01

In many ICUs, admission and discharge hinge on the need for intubation and ventilatory support. As few as 5% to 10% of ICU patients require prolonged mechanical ventilation, and this patient group consumes > or = 50% of ICU patient days and ICU resources. Prolonged ventilatory support and chronic ventilator dependency, both in the ICU and non-ICU settings, have a significant and growing impact on healthcare economics. In the United States, the need for prolonged mechanical ventilation is increasingly recognized as separate and distinct from the initial diagnosis and/or procedure that leads to hospitalization. This distinction has led to improved reimbursement under the prospective diagnosis-related group (DRG) system, and demands more precise accounting from healthcare providers responsible for these patients. Using both published and theoretical examples, mechanical ventilation in the United States is discussed, with a focus on cost containment. Included in the discussion are ventilator teams, standards of care, management protocols, stepdown units, rehabilitation units, and home care. The expanding role of total quality management (TQM) is also presented.

Tracheostomy and mechanical ventilation weaning in children affected by respiratory virus according to a weaning protocol in a pediatric intensive care unit in Argentina: an observational restrospective trial

PubMed Central

2011-01-01

We describe difficult weaning after prolonged mechanical ventilation in three tracheostomized children affected by respiratory virus infection. Although the spontaneous breathing trials were successful, the patients failed all extubations. Therefore a tracheostomy was performed and the weaning plan was begun. The strategy for weaning was the decrease of ventilation support combining pressure control ventilation (PCV) with increasing periods of continuous positive airway pressure + pressure support ventilation (CPAP + PSV) and then CPAP + PSV with increasing intervals of T-piece. They presented acute respiratory distress syndrome on admission with high requirements of mechanical ventilation (MV). Intervening factors in the capabilities and loads of the respiratory system were considered and optimized. The average MV time was 69 days and weaning time 31 days. We report satisfactory results within the context of a directed weaning protocol. PMID:21244710

Low-Flow Extracorporeal Carbon Dioxide Removal Using the Hemolung Respiratory Dialysis System® to Facilitate Lung-Protective Mechanical Ventilation in Acute Respiratory Distress Syndrome.

PubMed

Akkanti, Bindu; Rajagopal, Keshava; Patel, Kirti P; Aravind, Sangeeta; Nunez-Centanu, Emmanuel; Hussain, Rahat; Shabari, Farshad Raissi; Hofstetter, Wayne L; Vaporciyan, Ara A; Banjac, Igor S; Kar, Biswajit; Gregoric, Igor D; Loyalka, Pranav

2017-06-01

Extracorporeal carbon dioxide removal (ECCO 2 R) permits reductions in alveolar ventilation requirements that the lungs would otherwise have to provide. This concept was applied to a case of hypercapnia refractory to high-level invasive mechanical ventilator support. We present a case of an 18-year-old man who developed post-pneumonectomy acute respiratory distress syndrome (ARDS) after resection of a mediastinal germ cell tumor involving the left lung hilum. Hypercapnia and hypoxemia persisted despite ventilator support even at traumatic levels. ECCO 2 R using a miniaturized system was instituted and provided effective carbon dioxide elimination. This facilitated establishment of lung-protective ventilator settings and lung function recovery. Extracorporeal lung support increasingly is being applied to treat ARDS. However, conventional extracorporeal membrane oxygenation (ECMO) generally involves using large cannulae capable of carrying high flow rates. A subset of patients with ARDS has mixed hypercapnia and hypoxemia despite high-level ventilator support. In the absence of profound hypoxemia, ECCO 2 R may be used to reduce ventilator support requirements to lung-protective levels, while avoiding risks associated with conventional ECMO.

Convexity, Jensen's inequality, and benefits of noisy or biologically variable life support (Keynote Address)

NASA Astrophysics Data System (ADS)

Mutch, W. Alan C.

2005-05-01

Life support with a mechanical ventilator is used to manage patients with a variety of lung diseases including acute respiratory distress syndrome (ARDS). Recently, management of ARDS has concentrated on ventilating at lower airway pressure using lower tidal volume. A large international study demonstrated a 22% reduction in mortality with the low tidal volume approach. The potential advantages of adding physiologic noise with fractal characteristics to the respiratory rate and tidal volume as delivered by a mechanical ventilator are discussed. A so-called biologically variable ventilator (BVV), incorporating such noise, has been developed. Here we show that the benefits of noisy ventilation - at lower tidal volumes - can be deduced from a simple probabilistic result known as Jensen"s Inequality. Using the local convexity of the pressure-volume relationship in the lung we demonstrate that the addition of noise results in higher mean tidal volume or lower mean airway pressure. The consequence is enhanced gas exchange or less stress on the lungs, both clinically desirable. Jensen"s Inequality has important considerations in engineering, information theory and thermodynamics. Here is an example of the concept applied to medicine that may have important considerations for the clinical management of critically ill patients. Life support devices, such as mechanical ventilators, are of vital use in critical care units and operating rooms. These devices usually have monotonous output. Improving mechanical ventilators and other life support devices may be as simple as adding noise to their output signals.

Indoor Environmental Quality in Mechanically Ventilated, Energy-Efficient Buildings vs. Conventional Buildings.

PubMed

Wallner, Peter; Munoz, Ute; Tappler, Peter; Wanka, Anna; Kundi, Michael; Shelton, Janie F; Hutter, Hans-Peter

2015-11-06

Energy-efficient buildings need mechanical ventilation. However, there are concerns that inadequate mechanical ventilation may lead to impaired indoor air quality. Using a semi-experimental field study, we investigated if exposure of occupants of two types of buildings (mechanical vs. natural ventilation) differs with regard to indoor air pollutants and climate factors. We investigated living and bedrooms in 123 buildings (62 highly energy-efficient and 61 conventional buildings) built in the years 2010 to 2012 in Austria (mainly Vienna and Lower Austria). Measurements of indoor parameters (climate, chemical pollutants and biological contaminants) were conducted twice. In total, more than 3000 measurements were performed. Almost all indoor air quality and room climate parameters showed significantly better results in mechanically ventilated homes compared to those relying on ventilation from open windows and/or doors. This study does not support the hypothesis that occupants in mechanically ventilated low energy houses are exposed to lower indoor air quality.

What Is Acute Respiratory Distress Syndrome?

MedlinePlus

... used for ARDS include: ■■ Breathing support from a mechanical ventilator combined with oxygen therapy (See ATS fact sheets on Mechanical Ventilation and Oxygen Therapy at www. thoracic.org/ ...

Effect of nature-based sounds' intervention on agitation, anxiety, and stress in patients under mechanical ventilator support: a randomised controlled trial.

PubMed

Saadatmand, Vahid; Rejeh, Nahid; Heravi-Karimooi, Majideh; Tadrisi, Sayed Davood; Zayeri, Farid; Vaismoradi, Mojtaba; Jasper, Melanie

2013-07-01

Few studies have been conducted to investigate the effect of nature-based sounds (N-BS) on agitation, anxiety level and physiological signs of stress in patients under mechanical ventilator support. Non-pharmacological nursing interventions such as N-BS can be less expensive and efficient ways to alleviate anxiety and adverse effects of sedative medications in patients under mechanical ventilator support. This study was conducted to identify the effect of the nature-based sounds' intervention on agitation, anxiety level and physiological stress responses in patients under mechanical ventilation support. A randomized placebo-controlled trial design was used to conduct this study. A total of 60 patients aged 18-65 years under mechanical ventilation support in an intensive care unit were randomly assigned to the control and experimental groups. The patients in the intervention group received 90 min of N-BS. Pleasant nature sounds were played to the patients using media players and headphones. Patients' physiological signs were taken immediately before the intervention and at the 30th, 60th, 90th minutes and 30 min after the procedure had finished. The physiological signs of stress assessed were heart rate, respiratory rate, and blood pressure. Data were collected over eight months from Oct 2011 to June 2012. Anxiety levels and agitation were assessed using the Faces Anxiety Scale and Richmond Agitation Sedation Scale, respectively. The experimental group had significantly lower systolic blood pressure, diastolic blood pressure, anxiety and agitation levels than the control group. These reductions increased progressively in the 30th, 60th, 90th minutes, and 30 min after the procedure had finished indicating a cumulative dose effect. N-BS can provide an effective method of decreasing potentially harmful physiological responses arising from anxiety in mechanically ventilated patients. Nurses can incorporate N-BS intervention as a non-pharmacologic intervention into the daily care of patients under mechanical ventilation support in order to reduce their stress and anxiety. Copyright © 2012 Elsevier Ltd. All rights reserved.

Mechanical Ventilation and Bronchopulmonary Dysplasia.

PubMed

Keszler, Martin; Sant'Anna, Guilherme

2015-12-01

Mechanical ventilation is an important potentially modifiable risk factor for the development of bronchopulmonary dysplasia. Effective use of noninvasive respiratory support reduces the risk of lung injury. Lung volume recruitment and avoidance of excessive tidal volume are key elements of lung-protective ventilation strategies. Avoidance of oxidative stress, less invasive methods of surfactant administration, and high-frequency ventilation are also important factors in lung injury prevention. Copyright © 2015 Elsevier Inc. All rights reserved.

The influence of music during mechanical ventilation and weaning from mechanical ventilation: A review

PubMed Central

Hetland, Breanna; Lindquist, Ruth; Chlan, Linda L.

2015-01-01

Background Mechanical ventilation (MV) causes many distressing symptoms. Weaning, the gradual decrease in ventilator assistance leading to termination of MV, increases respiratory effort, which may exacerbate symptoms and prolong MV. Music, a non-pharmacological intervention without side effects may benefit patients during weaning from mechanical ventilatory support. Methods A narrative review of OVID Medline, PsychINFO, and CINAHL databases was conducted to examine the evidence for the use of music intervention in MV and MV weaning. Results Music intervention had a positive impact on ventilated patients; 16 quantitative and 2 qualitative studies were identified. Quantitative studies included randomized clinical trials (10), case controls (3), pilot studies (2) and a feasibility study. Conclusions Evidence supports music as an effective intervention that can lesson symptoms related to MV and promote effective weaning. It has potential to reduce costs and increase patient satisfaction. However, more studies are needed to establish its use during MV weaning. PMID:26227333

Respiratory mechanics in brain injury: A review.

PubMed

Koutsoukou, Antonia; Katsiari, Maria; Orfanos, Stylianos E; Kotanidou, Anastasia; Daganou, Maria; Kyriakopoulou, Magdalini; Koulouris, Nikolaos G; Rovina, Nikoletta

2016-02-04

Several clinical and experimental studies have shown that lung injury occurs shortly after brain damage. The responsible mechanisms involve neurogenic pulmonary edema, inflammation, the harmful action of neurotransmitters, or autonomic system dysfunction. Mechanical ventilation, an essential component of life support in brain-damaged patients (BD), may be an additional traumatic factor to the already injured or susceptible to injury lungs of these patients thus worsening lung injury, in case that non lung protective ventilator settings are applied. Measurement of respiratory mechanics in BD patients, as well as assessment of their evolution during mechanical ventilation, may lead to preclinical lung injury detection early enough, allowing thus the selection of the appropriate ventilator settings to avoid ventilator-induced lung injury. The aim of this review is to explore the mechanical properties of the respiratory system in BD patients along with the underlying mechanisms, and to translate the evidence of animal and clinical studies into therapeutic implications regarding the mechanical ventilation of these critically ill patients.

Mechanical ventilation strategies.

PubMed

Keszler, Martin

2017-08-01

Although only a small proportion of full term and late preterm infants require invasive respiratory support, they are not immune from ventilator-associated lung injury. The process of lung damage from mechanical ventilation is multifactorial and cannot be linked to any single variable. Atelectrauma and volutrauma have been identified as the most important and potentially preventable elements of lung injury. Respiratory support strategies for full term and late preterm infants have not been as thoroughly studied as those for preterm infants; consequently, a strong evidence base on which to make recommendations is lacking. The choice of modalities of support and ventilation strategies should be guided by the specific underlying pathophysiologic considerations and the ventilatory approach must be individualized for each patient based on the predominant pathophysiology at the time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mechanically ventilated children with 2009 pandemic influenza A/H1N1: results from the National Pediatric Intensive Care Registry in Japan.

PubMed

Tokuhira, Natsuko; Shime, Nobuaki; Inoue, Miho; Kawasaki, Tatsuya; Sakurai, Yoshio; Kurosaka, Norimasa; Ueta, Ikuya; Nakagawa, Satoshi

2012-09-01

To outline the characteristics, clinical course, and outcome of pediatric patients requiring mechanical ventilation with influenza A/H1N1 infection in Japan. Prospective case registry analysis. Eleven pediatric or general intensive care units in Japan. Consecutive patients infected with A/H1N1, aged from 1 month to 16 yrs old admitted to the intensive care unit for mechanical ventilation between July 2009 and March 2010. None. Eighty-one children, aged 6.3 [0.8-13.6] (median [interquartile range]) years, were enrolled. Seventy-four (91%) had mechanical ventilation with tracheal intubation. Median duration of mechanical ventilation was 4 days (range 0.04-87) and 18 patients (23%) required mechanical ventilation >7 days. Two patients (2%) required extracorporeal membrane oxygenation. The in-hospital mortality was 1%. Forty-one patients (50%) had at least one underlying chronic condition, including 31 with asthma. Associated clinical symptoms and diagnosis were as follows: acute respiratory distress syndrome (9%), asthma or bronchitis (37%), pneumonia (68%) with 8 (14%) having bacterial pneumonia, neurological symptoms (32%), myocarditis (2%), and rhabdomyolysis (1%). Therapeutic interventions include inotropic support (21%), methylprednisolone therapy (33%), and antimicrobial therapy (88%). Multivariate analysis revealed that inotropic support was the only statistically significant factor associated with mechanical ventilation for more than a week (odds ratio 5.5, 95% confidence interval 1.5-20.5, p = .005). The clinical presentations of pediatric patients requiring mechanical ventilation for A/H1N1 in Japan were diverse. In-hospital mortality of this population was remarkably low. Rapid access to medical facilities in combination with early administration of antiviral agents may have contributed to the low mortality in this population.

[Pressure support ventilation and proportional assist ventilation during weaning from mechanical ventilation].

PubMed

Aguirre-Bermeo, H; Bottiroli, M; Italiano, S; Roche-Campo, F; Santos, J A; Alonso, M; Mancebo, J

2014-01-01

To compare tolerance, duration of mechanical ventilation (MV) and clinical outcomes during weaning from MV in patients subjected to either pressure support ventilation (PSV) or proportional assist ventilation (PAV). A prospective, observational study was carried out. Intensive Care Unit. A total of 40 consecutive subjects were allocated to either the PSV or the PAV group until each group contained 20 patients. Patients were included in the study when they met the criteria to begin weaning and the attending physician decided to initiate the weaning process. The physician selected the modality and set the ventilatory parameters. None. Demographic data, respiratory mechanics, ventilatory parameters, duration of MV, and clinical outcomes (reintubation, tracheostomy, mortality). Baseline characteristics were similar in both groups. No significant differences were observed between the PSV and PAV groups in terms of the total duration of MV (10 [5-18] vs. 9 [7-19] days; P=.85), reintubation (5 [31%] vs. 3 [19%]; P=.69), or mortality (4 [20%] vs. 5 [25%] deaths; P=1). Eight patients (40%) in the PSV group and 6 patients (30%) in the PAV group (P=.74) required a return to volume assist-control ventilation due to clinical deterioration. Tolerance, duration of MV and clinical outcomes during weaning from mechanical ventilation were similar in PSV and PAV. Copyright © 2013 Elsevier España, S.L. and SEMICYUC. All rights reserved.

Effects of Natural Sounds on Pain: A Randomized Controlled Trial with Patients Receiving Mechanical Ventilation Support.

PubMed

Saadatmand, Vahid; Rejeh, Nahid; Heravi-Karimooi, Majideh; Tadrisi, Sayed Davood; Vaismoradi, Mojtaba; Jordan, Sue

2015-08-01

Nonpharmacologic pain management in patients receiving mechanical ventilation support in critical care units is under investigated. Natural sounds may help reduce the potentially harmful effects of anxiety and pain in hospitalized patients. The aim of this study was to examine the effect of pleasant, natural sounds on self-reported pain in patients receiving mechanical ventilation support, using a pragmatic parallel-arm, randomized controlled trial. The study was conducted in a general adult intensive care unit of a high-turnover teaching hospital, in Tehran, Iran. Between October 2011 and June 2012, we recruited 60 patients receiving mechanical ventilation support to the intervention (n = 30) and control arms (n = 30) of a pragmatic parallel-group, randomized controlled trial. Participants in both arms wore headphones for 90 minutes. Those in the intervention arm heard pleasant, natural sounds, whereas those in the control arm heard nothing. Outcome measures included the self-reported visual analog scale for pain at baseline; 30, 60, and 90 minutes into the intervention; and 30 minutes post-intervention. All patients approached agreed to participate. The trial arms were similar at baseline. Pain scores in the intervention arm fell and were significantly lower than in the control arm at each time point (p < .05). Administration of pleasant, natural sounds via headphones is a simple, safe, nonpharmacologic nursing intervention that may be used to allay pain for up to 120 minutes in patients receiving mechanical ventilation support. Copyright © 2015 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

[Lung protective ventilation. Ventilatory modes and ventilator parameters].

PubMed

Schädler, Dirk; Weiler, Norbert

2008-06-01

Mechanical ventilation has a considerable potential for injuring the lung tissue. Therefore, attention has to be paid to the proper choice of ventilatory mode and settings to secure lung-protective ventilation whenever possible. Such ventilator strategy should account for low tidal volume ventilation (6 ml/kg PBW), limited plateau pressure (30 to 35 cm H2O) and positive end-expiratory pressure (PEEP). It is unclear whether pressure controlled or volume controlled ventilation with square flow profile is beneficial. The adjustment of inspiration and expiration time should consider the actual breathing mechanics and anticipate the generation of intrinsic PEEP. Ventilatory modes with the possibility of supporting spontaneous breathing should be used as soon as possible.

Course of Weaning from Prolonged Mechanical Ventilation after Cardiac Surgery

PubMed Central

Herlihy, James P.; Koch, Stephen M.; Jackson, Robert; Nora, Hope

2006-01-01

In order to determine the temporal pattern of weaning from mechanical ventilation for patients undergoing prolonged mechanical ventilation after cardiac surgery, we performed a retrospective review of 21 patients' weaning courses at our long-term acute care hospital. Using multiple regression analysis of an estimate of individual patients' percentage of mechanical ventilator support per day (%MVSD), we determined that 14 of 21 patients (67%) showed a statistically significant quadratic or cubic relationship between time and %MVSD. These patients showed little or no improvement in their ventilator dependence until a point in time when, abruptly, they began to make rapid progress (a “wean turning point”), after which they progressed to discontinuation of mechanical ventilation in a relatively short period of time. The other 7 patients appeared to have a similar weaning pattern, although the data were not statistically significant. Most patients in the study group weaned from the ventilator through a specific temporal pattern that is newly described herein. Data analysis suggested that the mechanism for the development of a wean turning point was improvement of pulmonary mechanics rather than improvement in gas exchange or respiratory load. Although these observations need to be confirmed by a prospective trial, they may have implications for weaning cardiac surgery patients from prolonged mechanical ventilation, and possibly for weaning a broader group of patients who require prolonged mechanical ventilation. PMID:16878611

Reduction of duration and cost of mechanical ventilation in an intensive care unit by use of a ventilatory management team.

PubMed

Cohen, I L; Bari, N; Strosberg, M A; Weinberg, P F; Wacksman, R M; Millstein, B H; Fein, I A

1991-10-01

To test the hypothesis that a formal interdisciplinary team approach to managing ICU patients requiring mechanical ventilation enhances ICU efficiency. Retrospective review with cost-effectiveness analysis. A 20-bed medical-surgical ICU in a 450-bed community referral teaching hospital with a critical care fellowship training program. All patients requiring mechanical ventilation in the ICU were included, comparing patients admitted 1 yr before the inception of the ventilatory management team (group 1) with those patients admitted for 1 yr after the inception of the team (group 2). Group 1 included 198 patients with 206 episodes of mechanical ventilation and group 2 included 165 patients with 183 episodes of mechanical ventilation. A team consisting of an ICU attending physician, nurse, and respiratory therapist was formed to conduct rounds regularly and supervise the ventilatory management of ICU patients who were referred to the critical care service. The two study groups were demographically comparable. However, there were significant reductions in resource use in group 2. The number of days on mechanical ventilation decreased (3.9 days per episode of mechanical ventilation [95% confidence interval 0.3 to 7.5 days]), as did days in the ICU (3.3 days per episode of mechanical ventilation [90% confidence interval 0.3 to 6.3 days]), numbers of arterial blood gases (23.2 per episode of mechanical ventilation; p less than .001), and number of indwelling arterial catheters (1 per episode of mechanical ventilation; p less than .001). The estimated cost savings from these reductions was $1,303 per episode of mechanical ventilation. We conclude that a ventilatory management team, or some component thereof, can significantly and safely expedite the process of "weaning" patients from mechanical ventilatory support in the ICU.

[Concepts and monitoring of pulmonary mechanic in patients under ventilatory support in intensive care unit].

PubMed

Faustino, Eduardo Antonio

2007-06-01

In mechanical ventilation, invasive and noninvasive, the knowledge of respiratory mechanic physiology is indispensable to take decisions and into the efficient management of modern ventilators. Monitoring of pulmonary mechanic parameters is been recommended from all the review works and clinical research. The objective of this study was review concepts of pulmonary mechanic and the methods used to obtain measures in the bed side, preparing a rational sequence to obtain this data. It was obtained bibliographic review through data bank LILACS, MedLine and PubMed, from the last ten years. This review approaches parameters of resistance, pulmonary compliance and intrinsic PEEP as primordial into comprehension of acute respiratory failure and mechanic ventilatory support, mainly in acute respiratory distress syndrome (ARDS) and in chronic obstructive pulmonary disease (COPD). Monitoring pulmonary mechanics in patients under mechanical ventilation in intensive care units gives relevant informations and should be implemented in a rational and systematic way.

Intraoperative mechanical ventilation for the pediatric patient.

PubMed

Kneyber, Martin C J

2015-09-01

Invasive mechanical ventilation is required when children undergo general anesthesia for any procedure. It is remarkable that one of the most practiced interventions such as pediatric mechanical ventilation is hardly supported by any scientific evidence but rather based on personal experience and data from adults, especially as ventilation itself is increasingly recognized as a harmful intervention that causes ventilator-induced lung injury. The use of low tidal volume and higher levels of positive end-expiratory pressure became an integral part of lung-protective ventilation following the outcomes of clinical trials in critically ill adults. This approach has been readily adopted in pediatric ventilation. However, a clear association between tidal volume and mortality has not been ascertained in pediatrics. In fact, experimental studies have suggested that young children might be less susceptible to ventilator-induced lung injury. As such, no recommendations on optimal lung-protective ventilation strategy in children with or without lung injury can be made. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inhalation therapy in mechanical ventilation

PubMed Central

Maccari, Juçara Gasparetto; Teixeira, Cassiano; Gazzana, Marcelo Basso; Savi, Augusto; Dexheimer-Neto, Felippe Leopoldo; Knorst, Marli Maria

2015-01-01

Patients with obstructive lung disease often require ventilatory support via invasive or noninvasive mechanical ventilation, depending on the severity of the exacerbation. The use of inhaled bronchodilators can significantly reduce airway resistance, contributing to the improvement of respiratory mechanics and patient-ventilator synchrony. Although various studies have been published on this topic, little is known about the effectiveness of the bronchodilators routinely prescribed for patients on mechanical ventilation or about the deposition of those drugs throughout the lungs. The inhaled bronchodilators most commonly used in ICUs are beta adrenergic agonists and anticholinergics. Various factors might influence the effect of bronchodilators, including ventilation mode, position of the spacer in the circuit, tube size, formulation, drug dose, severity of the disease, and patient-ventilator synchrony. Knowledge of the pharmacological properties of bronchodilators and the appropriate techniques for their administration is fundamental to optimizing the treatment of these patients. PMID:26578139

Ultrasonographic Evaluation of Diaphragm Thickness During Mechanical Ventilation in Intensive Care Patients.

PubMed

Francis, Colin Anthony; Hoffer, Joaquín Andrés; Reynolds, Steven

2016-01-01

Mechanical ventilation is associated with atrophy and weakness of the diaphragm. Ultrasound is an easy noninvasive way to track changes in thickness of the diaphragm. To validate ultrasound as a means of tracking thickness of the diaphragm in patients undergoing mechanical ventilation by evaluating interobserver and interoperator reliability and to collect initial data on the relationship of mode of ventilation to changes in the diaphragm. Daily ultrasound images of the quadriceps and the right side of the diaphragm were acquired in 8 critically ill patients receiving various modes of mechanical ventilation. Thickness of the diaphragm and the quadriceps was measured, and changes with time were noted. Interoperator and interobserver reliability were measured. Intraclass correlation coefficients between operators and between observers for thickness of the diaphragm and quadriceps were greater than 0.95, indicating excellent interoperator and interobserver reliability. Patients receiving assist-control ventilation (n = 4) showed a mean decline in diaphragm thickness of 4.7% per day. Patients receiving pressure support ventilation (n = 8) showed a mean increase in diaphragm thickness of 1.5% per day. Quadriceps thickness declined in all participants (n = 8) at a mean rate of 2.0% per day. Use of ultrasound to measure thickness of the diaphragm in 8 intensive care patients undergoing various modes of mechanical ventilation was feasible and yielded reproducible results. Ultrasound tracking of changes in thickness of the diaphragm in this small sample indicated that the thickness decreased during assist-control mode and increased during pressure support mode. ©2016 American Association of Critical-Care Nurses.

Recommendations for mechanical ventilation of critically ill children from the Paediatric Mechanical Ventilation Consensus Conference (PEMVECC).

PubMed

Kneyber, Martin C J; de Luca, Daniele; Calderini, Edoardo; Jarreau, Pierre-Henri; Javouhey, Etienne; Lopez-Herce, Jesus; Hammer, Jürg; Macrae, Duncan; Markhorst, Dick G; Medina, Alberto; Pons-Odena, Marti; Racca, Fabrizio; Wolf, Gerhard; Biban, Paolo; Brierley, Joe; Rimensberger, Peter C

2017-12-01

Much of the common practice in paediatric mechanical ventilation is based on personal experiences and what paediatric critical care practitioners have adopted from adult and neonatal experience. This presents a barrier to planning and interpretation of clinical trials on the use of specific and targeted interventions. We aim to establish a European consensus guideline on mechanical ventilation of critically children. The European Society for Paediatric and Neonatal Intensive Care initiated a consensus conference of international European experts in paediatric mechanical ventilation to provide recommendations using the Research and Development/University of California, Los Angeles, appropriateness method. An electronic literature search in PubMed and EMBASE was performed using a combination of medical subject heading terms and text words related to mechanical ventilation and disease-specific terms. The Paediatric Mechanical Ventilation Consensus Conference (PEMVECC) consisted of a panel of 15 experts who developed and voted on 152 recommendations related to the following topics: (1) general recommendations, (2) monitoring, (3) targets of oxygenation and ventilation, (4) supportive measures, (5) weaning and extubation readiness, (6) normal lungs, (7) obstructive diseases, (8) restrictive diseases, (9) mixed diseases, (10) chronically ventilated patients, (11) cardiac patients and (12) lung hypoplasia syndromes. There were 142 (93.4%) recommendations with "strong agreement". The final iteration of the recommendations had none with equipoise or disagreement. These recommendations should help to harmonise the approach to paediatric mechanical ventilation and can be proposed as a standard-of-care applicable in daily clinical practice and clinical research.

Tracheostomy and invasive mechanical ventilation in amyotrophic lateral sclerosis: decision-making factors and survival analysis.

PubMed

Kimura, Fumiharu

2016-04-28

Invasive and/or non-invasive mechanical ventilation are most important options of respiratory management in amyotrophic lateral sclerosis. We evaluated the frequency, clinical characteristics, decision-making factors about ventilation and survival analysis of 190 people with amyotrophic lateral sclerosis patients from 1990 until 2013. Thirty-one percentage of patients underwent tracheostomy invasive ventilation with the rate increasing more than the past 20 years. The ratio of tracheostomy invasive ventilation in patients >65 years old was significantly increased after 2000 (25%) as compared to before (10%). After 2010, the standard use of non-invasive ventilation showed a tendency to reduce the frequency of tracheostomy invasive ventilation. Mechanical ventilation prolonged median survival (75 months in tracheostomy invasive ventilation, 43 months in non-invasive ventilation vs natural course, 32 months). The life-extending effects by tracheostomy invasive ventilation were longer in younger patients ≤65 years old at the time of ventilation support than in older patients. Presence of partners and care at home were associated with better survival. Following factors related to the decision to perform tracheostomy invasive ventilation: patients ≤65 years old: greater use of non-invasive ventilation: presence of a spouse: faster tracheostomy: higher progression rate; and preserved motor functions. No patients who underwent tracheostomy invasive ventilation died from a decision to withdraw mechanical ventilation. The present study provides factors related to decision-making process and survival after tracheostomy and help clinicians and family members to expand the knowledge about ventilation.

Impact of Prolonged Mechanical Ventilation in Very Low Birth Weight Infants: Results From a National Cohort Study.

PubMed

Choi, Young-Bin; Lee, Juyoung; Park, Jisun; Jun, Yong Hoon

2018-03-01

To evaluate the in-hospital consequences of prolonged respiratory support with invasive mechanical ventilation in very low birth weight infants. A cohort study was performed using prospectively collected data from 69 neonatal intensive care units participating in the Korean national registry. In total, 3508 very low birth weight infants born between January 1, 2013 and December 31, 2014 were reviewed. The adjusted hazard ratio for death increased significantly for infants who received mechanical ventilation for more than 2 weeks compared with those were mechanically ventilated for 7 days or less. The individual mortality rate increased after 8 weeks, reaching 50% and 60% at 14 and 16 weeks of cumulative mechanical ventilation, respectively. After adjusting for potential confounders, the cumulative duration of mechanical ventilation was associated with a clinically significant increase in the odds of bronchopulmonary dysplasia and pulmonary hypertension. Mechanical ventilation exposure for longer than 2 weeks, compared with 7 days or less, was associated with retinopathy of prematurity requiring laser coagulation and periventricular leukomalacia. The odds of abnormal auditory screening test results were significantly increased in infants who needed mechanical ventilation for more than 4 weeks. A longer cumulative duration of mechanical ventilation was associated with increased lengths of hospitalization and parenteral nutrition and a higher probability of discharge with poor achievement of physical growth. Although mechanical ventilation is a life-saving intervention for premature infants, these results indicate that it is associated with negative consequences when applied for prolonged periods. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of Multiple Ventilation Courses and Duration of Mechanical Ventilation on Respiratory Outcomes in Extremely Low-Birth-Weight Infants.

PubMed

Jensen, Erik A; DeMauro, Sara B; Kornhauser, Michael; Aghai, Zubair H; Greenspan, Jay S; Dysart, Kevin C

2015-11-01

Extubation failure is common in extremely preterm infants. The current paucity of data on the adverse long-term respiratory outcomes associated with reinitiation of mechanical ventilation prevents assessment of the risks and benefits of a trial of extubation in this population. To evaluate whether exposure to multiple courses of mechanical ventilation increases the risk of adverse respiratory outcomes before and after adjustment for the cumulative duration of mechanical ventilation. We performed a retrospective cohort study of extremely low-birth-weight (ELBW; birth weight <1000 g) infants born from January 1, 2006, through December 31, 2012, who were receiving mechanical ventilation. Analysis was conducted between November 2014 and February 2015. Data were obtained from the Alere Neonatal Database. The primary study exposures were the cumulative duration of mechanical ventilation and the number of ventilation courses. The primary outcome was bronchopulmonary dysplasia (BPD) among survivors. Secondary outcomes were death, use of supplemental oxygen at discharge, and tracheostomy. We identified 3343 ELBW infants, of whom 2867 (85.8%) survived to discharge. Among the survivors, 1695 (59.1%) were diagnosed as having BPD, 856 (29.9%) received supplemental oxygen at discharge, and 31 (1.1%) underwent tracheostomy. Exposure to a greater number of mechanical ventilation courses was associated with a progressive increase in the risk of BPD and use of supplemental oxygen at discharge. Compared with a single ventilation course, the adjusted odds ratios for BPD ranged from 1.88 (95% CI, 1.54-2.31) among infants with 2 ventilation courses to 3.81 (95% CI, 2.88-5.04) among those with 4 or more courses. After adjustment for the cumulative duration of mechanical ventilation, the odds of BPD were only increased among infants exposed to 4 or more ventilation courses (adjusted odds ratio, 1.44; 95% CI, 1.04-2.01). The number of ventilation courses was not associated with increased risk of supplemental oxygen use at discharge after adjustment for the length of ventilation. A greater number of ventilation courses did not increase the risk of tracheostomy. Among ELBW infants, a longer cumulative duration of mechanical ventilation largely accounts for the increased risk of chronic respiratory morbidity associated with reinitiation of mechanical ventilation. These results support attempts of extubation in ELBW infants receiving mechanical ventilation on low ventilator settings, even when success is not guaranteed.

Extracorporeal respiratory support in adult patients

PubMed Central

Romano, Thiago Gomes; Mendes, Pedro Vitale; Park, Marcelo; Costa, Eduardo Leite Vieira

2017-01-01

ABSTRACT In patients with severe respiratory failure, either hypoxemic or hypercapnic, life support with mechanical ventilation alone can be insufficient to meet their needs, especially if one tries to avoid ventilator settings that can cause injury to the lungs. In those patients, extracorporeal membrane oxygenation (ECMO), which is also very effective in removing carbon dioxide from the blood, can provide life support, allowing the application of protective lung ventilation. In this review article, we aim to explore some of the most relevant aspects of using ECMO for respiratory support. We discuss the history of respiratory support using ECMO in adults, as well as the clinical evidence; costs; indications; installation of the equipment; ventilator settings; daily care of the patient and the system; common troubleshooting; weaning; and discontinuation. PMID:28380189

Understanding nurses' decision-making when managing weaning from mechanical ventilation: a study of novice and experienced critical care nurses in Scotland and Greece.

PubMed

Kydonaki, Kalliopi; Huby, Guro; Tocher, Jennifer; Aitken, Leanne M

2016-02-01

To examine how nurses collect and use cues from respiratory assessment to inform their decisions as they wean patients from ventilatory support. Prompt and accurate identification of the patient's ability to sustain reduction of ventilatory support has the potential to increase the likelihood of successful weaning. Nurses' information processing during the weaning from mechanical ventilation has not been well-described. A descriptive ethnographic study exploring critical care nurses' decision-making processes when weaning mechanically ventilated patients from ventilatory support in the real setting. Novice and expert Scottish and Greek nurses from two tertiary intensive care units were observed in real practice of weaning mechanical ventilation and were invited to participate in reflective interviews near the end of their shift. Data were analysed thematically using concept maps based on information processing theory. Ethics approval and informed consent were obtained. Scottish and Greek critical care nurses acquired patient-centred objective physiological and subjective information from respiratory assessment and previous knowledge of the patient, which they clustered around seven concepts descriptive of the patient's ability to wean. Less experienced nurses required more encounters of cues to attain the concepts with certainty. Subjective criteria were intuitively derived from previous knowledge of patients' responses to changes of ventilatory support. All nurses used focusing decision-making strategies to select and group cues in order to categorise information with certainty and reduce the mental strain of the decision task. Nurses used patient-centred information to make a judgment about the patients' ability to wean. Decision-making strategies that involve categorisation of patient-centred information can be taught in bespoke educational programmes for mechanical ventilation and weaning. Advanced clinical reasoning skills and accurate detection of cues in respiratory assessment by critical care nurses will ensure optimum patient management in weaning mechanical ventilation. © 2016 John Wiley & Sons Ltd.

Mechanical ventilation and sepsis impair protein metabolism in the diaphragm of neonatal pigs

USDA-ARS?s Scientific Manuscript database

Mechanical ventilation (MV) impairs diaphragmatic function and diminishes the ability to wean from ventilatory support in adult humans. In normal neonatal pigs, animals that are highly anabolic, endotoxin (LPS) infusion induces sepsis, reduces peripheral skeletal muscle protein synthesis rates, but ...

Special Considerations in Neonatal Mechanical Ventilation.

PubMed

Dalgleish, Stacey; Kostecky, Linda; Charania, Irina

2016-12-01

Care of infants supported with mechanical ventilation is complex, time intensive, and requires constant vigilance by an expertly prepared health care team. Current evidence must guide nursing practice regarding ventilated neonates. This article highlights the importance of common language to establish a shared mental model and enhance clear communication among the interprofessional team. Knowledge regarding the underpinnings of an open lung strategy and the interplay between the pathophysiology and individual infant's response to a specific ventilator strategy is most likely to result in a positive clinical outcome. Copyright © 2016 Elsevier Inc. All rights reserved.

Respiratory muscle dysfunction: a multicausal entity in the critically ill patient undergoing mechanical ventilation.

PubMed

Díaz, Magda C; Ospina-Tascón, Gustavo A; Salazar C, Blanca C

2014-02-01

Respiratory muscle dysfunction, particularly of the diaphragm, may play a key role in the pathophysiological mechanisms that lead to difficulty in weaning patients from mechanical ventilation. The limited mobility of critically ill patients, and of the diaphragm in particular when prolonged mechanical ventilation support is required, promotes the early onset of respiratory muscle dysfunction, but this can also be caused or exacerbated by other factors that are common in these patients, such as sepsis, malnutrition, advanced age, duration and type of ventilation, and use of certain medications, such as steroids and neuromuscular blocking agents. In this review we will study in depth this multicausal origin, in which a common mechanism is altered protein metabolism, according to the findings reported in various models. The understanding of this multicausality produced by the same pathophysiological mechanism could facilitate the management and monitoring of patients undergoing mechanical ventilation. Copyright © 2012 SEPAR. Published by Elsevier Espana. All rights reserved.

The Clinical Utilisation of Respiratory Elastance Software (CURE Soft): a bedside software for real-time respiratory mechanics monitoring and mechanical ventilation management.

PubMed

Szlavecz, Akos; Chiew, Yeong Shiong; Redmond, Daniel; Beatson, Alex; Glassenbury, Daniel; Corbett, Simon; Major, Vincent; Pretty, Christopher; Shaw, Geoffrey M; Benyo, Balazs; Desaive, Thomas; Chase, J Geoffrey

2014-09-30

Real-time patient respiratory mechanics estimation can be used to guide mechanical ventilation settings, particularly, positive end-expiratory pressure (PEEP). This work presents a software, Clinical Utilisation of Respiratory Elastance (CURE Soft), using a time-varying respiratory elastance model to offer this ability to aid in mechanical ventilation treatment. CURE Soft is a desktop application developed in JAVA. It has two modes of operation, 1) Online real-time monitoring decision support and, 2) Offline for user education purposes, auditing, or reviewing patient care. The CURE Soft has been tested in mechanically ventilated patients with respiratory failure. The clinical protocol, software testing and use of the data were approved by the New Zealand Southern Regional Ethics Committee. Using CURE Soft, patient's respiratory mechanics response to treatment and clinical protocol were monitored. Results showed that the patient's respiratory elastance (Stiffness) changed with the use of muscle relaxants, and responded differently to ventilator settings. This information can be used to guide mechanical ventilation therapy and titrate optimal ventilator PEEP. CURE Soft enables real-time calculation of model-based respiratory mechanics for mechanically ventilated patients. Results showed that the system is able to provide detailed, previously unavailable information on patient-specific respiratory mechanics and response to therapy in real-time. The additional insight available to clinicians provides the potential for improved decision-making, and thus improved patient care and outcomes.

Physiology in Medicine: Understanding dynamic alveolar physiology to minimize ventilator-induced lung injury.

PubMed

Nieman, Gary F; Satalin, Josh; Kollisch-Singule, Michaela; Andrews, Penny; Aiash, Hani; Habashi, Nader M; Gatto, Louis A

2017-06-01

Acute respiratory distress syndrome (ARDS) remains a serious clinical problem with the main treatment being supportive in the form of mechanical ventilation. However, mechanical ventilation can be a double-edged sword: if set improperly, it can exacerbate the tissue damage caused by ARDS; this is known as ventilator-induced lung injury (VILI). To minimize VILI, we must understand the pathophysiologic mechanisms of tissue damage at the alveolar level. In this Physiology in Medicine paper, the dynamic physiology of alveolar inflation and deflation during mechanical ventilation will be reviewed. In addition, the pathophysiologic mechanisms of VILI will be reviewed, and this knowledge will be used to suggest an optimal mechanical breath profile (MB P : all airway pressures, volumes, flows, rates, and the duration that they are applied at both inspiration and expiration) necessary to minimize VILI. Our review suggests that the current protective ventilation strategy, known as the "open lung strategy," would be the optimal lung-protective approach. However, the viscoelastic behavior of dynamic alveolar inflation and deflation has not yet been incorporated into protective mechanical ventilation strategies. Using our knowledge of dynamic alveolar mechanics (i.e., the dynamic change in alveolar and alveolar duct size and shape during tidal ventilation) to modify the MB P so as to minimize VILI will reduce the morbidity and mortality associated with ARDS. Copyright © 2017 the American Physiological Society.

Numerical investigation of pulmonary drug delivery under mechanical ventilation conditions

NASA Astrophysics Data System (ADS)

Banerjee, Arindam; van Rhein, Timothy

2012-11-01

The effects of mechanical ventilation waveform on fluid flow and particle deposition were studied in a computer model of the human airways. The frequency with which aerosolized drugs are delivered to mechanically ventilated patients demonstrates the importance of understanding the effects of ventilation parameters. This study focuses specifically on the effects of mechanical ventilation waveforms using a computer model of the airways of patient undergoing mechanical ventilation treatment from the endotracheal tube to generation G7. Waveforms were modeled as those commonly used by commercial mechanical ventilators. Turbulence was modeled with LES. User defined particle force models were used to model the drag force with the Cunningham correction factor, the Saffman lift force, and Brownian motion force. The endotracheal tube (ETT) was found to be an important geometric feature, causing a fluid jet towards the right main bronchus, increased turbulence, and a recirculation zone in the right main bronchus. In addition to the enhanced deposition seen at the carinas of the airway bifurcations, enhanced deposition was also seen in the right main bronchus due to impaction and turbulent dispersion resulting from the fluid structures created by the ETT. Authors acknowledge financial support through University of Missouri Research Board Award.

Protective lung ventilation in operating room: a systematic review.

PubMed

Futier, E; Constantin, J M; Jaber, S

2014-06-01

Postoperative pulmonary and extrapulmonary complications adversely affect clinical outcomes and healthcare utilization, so that prevention has become a measure of the quality of perioperative care. Mechanical ventilation is an essential support therapy to maintain adequate gas exchange during general anesthesia for surgery. Mechanical ventilation using high tidal volume (VT) (between 10 and 15 mL/kg) has been historically encouraged to prevent hypoxemia and atelectasis formation in anesthetized patients undergoing abdominal and thoracic surgery. However, there is accumulating evidence from both experimental and clinical studies that mechanical ventilation, especially the use of high VT and plateau pressure, may potentially aggravate or even initiate lung injury. Ventilator-associated lung injury can result from cyclic alveolar overdistension of non-dependent lung tissue, and repetitive opening and closing of dependent lung tissue resulting in ultrastructural damage at the junction of closed and open alveoli. Lung-protective ventilation, which refers to the use of lower VT and limited plateau pressure to minimize overdistension, and positive end-expiratory pressure to prevent alveolar collapse at end-expiration, was shown to improve outcome in critically ill patients with acute respiratory distress syndrome (ARDS). It has been recently suggested that this approach might also be beneficial in a broader population, especially in critically ill patients without ARDS at the onset of mechanical ventilation. There is, however, little evidence regarding a potential beneficial effect of lung protective ventilation during surgery, especially in patients with healthy lungs. Although surgical patients are frequently exposed to much shorter periods of mechanical ventilation, this is an important gap in knowledge given the number of patients receiving mechanical ventilation in the operating room. This review developed the benefits of lung protective ventilation during surgery and general anesthesia and offers some recommendations for mechanical ventilation in the surgical context.

Mechanical ventilation and sepsis induce skeletal muscle catabolism in neonatal pigs

USDA-ARS?s Scientific Manuscript database

Reduced rates of skeletal muscle accretion are a prominent feature of the metabolic response to sepsis in infants and children. Septic neonates often require medical support with mechanical ventilation (MV). The combined effects of MV and sepsis in muscle have not been examined in neonates, in whom ...

Mechanical ventilation alone, and in the presence of sepsis, impair protein metabolism in the diaphragm of neonatal pigs

USDA-ARS?s Scientific Manuscript database

Mechanical ventilation (MV) impairs diaphragmatic function and diminishes the ability to wean from ventilatory support in adult humans. In normal neonatal pigs, animals that are highly anabolic, endotoxin (LPS) infusion induces sepsis, reduces peripheral skeletal muscle protein synthesis rates, but ...

Atelectasis is inversely proportional to transpulmonary pressure during weaning from ventilator support in a large animal model.

PubMed

Gudmundsson, M; Perchiazzi, G; Pellegrini, M; Vena, A; Hedenstierna, G; Rylander, C

2018-01-01

In mechanically ventilated, lung injured, patients without spontaneous breathing effort, atelectasis with shunt and desaturation may appear suddenly when ventilator pressures are decreased. It is not known how such a formation of atelectasis is related to transpulmonary pressure (P L ) during weaning from mechanical ventilation when the spontaneous breathing effort is increased. If the relation between P L and atelectasis were known, monitoring of P L might help to avoid formation of atelectasis and cyclic collapse during weaning. The main purpose of this study was to determine the relation between P L and atelectasis in an experimental model representing weaning from mechanical ventilation. Dynamic transverse computed tomography scans were acquired in ten anaesthetized, surfactant-depleted pigs with preserved spontaneous breathing, as ventilator support was lowered by sequentially reducing inspiratory pressure and positive end expiratory pressure in steps. The volumes of gas and atelectasis in the lungs were correlated with P L obtained using oesophageal pressure recordings. Work of breathing (WOB) was assessed from Campbell diagrams. Gradual decrease in P L in both end-expiration and end-inspiration caused a proportional increase in atelectasis and decrease in the gas content (linear mixed model with an autoregressive correlation matrix; P < 0.001) as the WOB increased. However, cyclic alveolar collapse during tidal ventilation did not increase significantly. We found a proportional correlation between atelectasis and P L during the 'weaning process' in experimental mild lung injury. If confirmed in the clinical setting, a gradual tapering of ventilator support can be recommended for weaning without risk of sudden formation of atelectasis. © 2017 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Mechanical ventilation for severe asthma.

PubMed

Leatherman, James

2015-06-01

Acute exacerbations of asthma can lead to respiratory failure requiring ventilatory assistance. Noninvasive ventilation may prevent the need for endotracheal intubation in selected patients. For patients who are intubated and undergo mechanical ventilation, a strategy that prioritizes avoidance of ventilator-related complications over correction of hypercapnia was first proposed 30 years ago and has become the preferred approach. Excessive pulmonary hyperinflation is a major cause of hypotension and barotrauma. An appreciation of the key determinants of hyperinflation is essential to rational ventilator management. Standard therapy for patients with asthma undergoing mechanical ventilation consists of inhaled bronchodilators, corticosteroids, and drugs used to facilitate controlled hypoventilation. Nonconventional interventions such as heliox, general anesthesia, bronchoscopy, and extracorporeal life support have also been advocated for patients with fulminant asthma but are rarely necessary. Immediate mortality for patients who are mechanically ventilated for acute severe asthma is very low and is often associated with out-of-hospital cardiorespiratory arrest before intubation. However, patients who have been intubated for severe asthma are at increased risk for death from subsequent exacerbations and must be managed accordingly in the outpatient setting.

A Contemporary Assessment of Acute Mechanical Ventilation in Beijing: Description, Costs, and Outcomes.

PubMed

Ye, Yanping; Zhu, Bo; Jiang, Li; Jiang, Qi; Wang, Meiping; Hua, Lin; Xi, Xiuming

2017-07-01

To evaluate the contemporary practice, outcomes, and costs related to mechanical ventilation among ICUs in China. A prospective observational cohort study. Fourteen ICUs among 13 hospitals in Beijing, China. Seven hundred ninety-three patients who received at least 24 hours of mechanical ventilation within the first 48 hours of ICU stay. None. The mean age was 64 years. Sixty-three percent were male. New acute respiratory failure accounted for 85.5% of mechanical ventilation cases. Only 4.7% of the patients received mechanical ventilation for acute exacerbation of chronic obstructive pulmonary disease. The most widely used ventilation mode was the combination of synchronized intermittent mandatory ventilation and pressure support (43.6%). Use of lung-protective ventilation is widespread with tidal volumes of 7.1 mL/kg (2.1 mL/kg). The ICU/hospital mortality was 27.6%/29.3%, respectively (8.5%/9.7% for surgical patients and 41.3%/43.2% for medical patients, respectively). The mean level of ICU/hospital cost per patient was $15,271 (18,940)/$22,946 (25,575), respectively. The mean daily ICU cost per patient was $1,212. For the first time, we obtained a preliminary epidemiology data of mechanical ventilation in Beijing, China, through the study. Compared with the other nations, our patients are older, predominantly male, and treated according to prevailing international guidelines yet at a relatively high cost and high mortality. The expanding elderly population predicts increase demand for mechanical ventilation that must be met by continuous improvement in quality and efficiency of critical care services.

Mechanical ventilation management during extracorporeal membrane oxygenation for acute respiratory distress syndrome: a retrospective international multicenter study.

PubMed

Schmidt, Matthieu; Stewart, Claire; Bailey, Michael; Nieszkowska, Ania; Kelly, Joshua; Murphy, Lorna; Pilcher, David; Cooper, D James; Scheinkestel, Carlos; Pellegrino, Vincent; Forrest, Paul; Combes, Alain; Hodgson, Carol

2015-03-01

To describe mechanical ventilation settings in adult patients treated for an acute respiratory distress syndrome with extracorporeal membrane oxygenation and assess the potential impact of mechanical ventilation settings on ICU mortality. Retrospective observational study. Three international high-volume extracorporeal membrane oxygenation centers. A total of 168 patients treated with extracorporeal membrane oxygenation for severe acute respiratory distress syndrome from January 2007 to January 2013. We analyzed the association between mechanical ventilation settings (i.e. plateau pressure, tidal volume, and positive end-expiratory pressure) on ICU mortality using multivariable logistic regression model and Cox-proportional hazards model. We obtained detailed demographic, clinical, daily mechanical ventilation settings and ICU outcome data. One hundred sixty-eight patients (41 ± 14 years old; PaO2/FIO2 67 ± 19 mm Hg) fulfilled our inclusion criteria. Median duration of extracorporeal membrane oxygenation and ICU stay were 10 days (6-18 d) and 28 days (16-42 d), respectively. Lower positive end-expiratory pressure levels and significantly lower plateau pressures during extracorporeal membrane oxygenation were used in the French center than in both Australian centers (23.9 ± 1.4 vs 27.6 ± 3.7 and 27.8 ± 3.6; p < 0.0001). Overall ICU mortality was 29%. Lower positive end-expiratory pressure levels (until day 7) and lower delivered tidal volume after 3 days on extracorporeal membrane oxygenation were associated with significantly higher mortality (p < 0.05). In multivariate analysis, higher positive end-expiratory pressure levels during the first 3 days of extracorporeal membrane oxygenation support were associated with lower mortality (odds ratio, 0.75; 95% CI, 0.64-0.88; p = 0.0006). Other independent predictors of ICU mortality included time between ICU admission and extracorporeal membrane oxygenation initiation, plateau pressure greater than 30 cm H2O before extracorporeal membrane oxygenation initiation, and lactate level on day 3 of extracorporeal membrane oxygenation support. Protective mechanical ventilation strategies were routinely used in high-volume extracorporeal membrane oxygenation centers. However, higher positive end-expiratory pressure levels during the first 3 days on extracorporeal membrane oxygenation support were independently associated with improved survival. Further prospective trials on the optimal mechanical ventilation strategy during extracorporeal membrane oxygenation support are warranted.

[Cases and duration of mechanical ventilation in German hospitals : An analysis of DRG incentives and developments in respiratory medicine].

PubMed

Biermann, A; Geissler, A

2016-09-01

Diagnosis-related groups (DRGs) have been used to reimburse hospitals services in Germany since 2003/04. Like any other reimbursement system, DRGs offer specific incentives for hospitals that may lead to unintended consequences for patients. In the German context, specific procedures and their documentation are suspected to be primarily performed to increase hospital revenues. Mechanical ventilation of patients and particularly the duration of ventilation, which is an important variable for the DRG-classification, are often discussed to be among these procedures. The aim of this study was to examine incentives created by the German DRG-based payment system with regard to mechanical ventilation and to identify factors that explain the considerable increase of mechanically ventilated patients in recent years. Moreover, the assumption that hospitals perform mechanical ventilation in order to gain economic benefits was examined. In order to gain insights on the development of the number of mechanically ventilated patients, patient-level data provided by the German Federal Statistical Office and the German Institute for the Hospital Remuneration System were analyzed. The type of performed ventilation, the total number of ventilation hours, the age distribution, mortality and the DRG distribution for mechanical ventilation were calculated, using methods of descriptive and inferential statistics. Furthermore, changes in DRG-definitions and changes in respiratory medicine were compared for the years 2005-2012. Since the introduction of the DRG-based payment system in Germany, the hours of ventilation and the number of mechanically ventilated patients have substantially increased, while mortality has decreased. During the same period there has been a switch to less invasive ventilation methods. The age distribution has shifted to higher age-groups. A ventilation duration determined by DRG definitions could not be found. Due to advances in respiratory medicine, new ventilation methods have been introduced that are less prone to complications. This development has simultaneously improved survival rates. There was no evidence supporting the assumption that the duration of mechanical ventilation is influenced by the time intervals relevant for DRG grouping. However, presumably operational routines such as staff availability within early and late shifts of the hospital have a significant impact on the termination of mechanical ventilation.

Clinical Practice Guideline of Acute Respiratory Distress Syndrome

PubMed Central

Cho, Young-Jae; Moon, Jae Young; Shin, Ein-Soon; Kim, Je Hyeong; Jung, Hoon; Park, So Young; Kim, Ho Cheol; Sim, Yun Su; Rhee, Chin Kook; Lim, Jaemin; Lee, Seok Jeong; Lee, Won-Yeon; Lee, Hyun Jeong; Kwak, Sang Hyun; Kang, Eun Kyeong; Chung, Kyung Soo

2016-01-01

There is no well-stated practical guideline for mechanically ventilated patients with or without acute respiratory distress syndrome (ARDS). We generate strong (1) and weak (2) grade of recommendations based on high (A), moderate (B) and low (C) grade in the quality of evidence. In patients with ARDS, we recommend low tidal volume ventilation (1A) and prone position if it is not contraindicated (1B) to reduce their mortality. However, we did not support high-frequency oscillatory ventilation (1B) and inhaled nitric oxide (1A) as a standard treatment. We also suggest high positive end-expiratory pressure (2B), extracorporeal membrane oxygenation as a rescue therapy (2C), and neuromuscular blockage for 48 hours after starting mechanical ventilation (2B). The application of recruitment maneuver may reduce mortality (2B), however, the use of systemic steroids cannot reduce mortality (2B). In mechanically ventilated patients, we recommend light sedation (1B) and low tidal volume even without ARDS (1B) and suggest lung protective ventilation strategy during the operation to lower the incidence of lung complications including ARDS (2B). Early tracheostomy in mechanically ventilated patients can be performed only in limited patients (2A). In conclusion, of 12 recommendations, nine were in the management of ARDS, and three for mechanically ventilated patients. PMID:27790273

Technology for noninvasive mechanical ventilation: looking into the black box

PubMed Central

Navajas, Daniel; Montserrat, Josep M.

2016-01-01

Current devices for providing noninvasive respiratory support contain sensors and built-in intelligence for automatically modifying ventilation according to the patient's needs. These devices, including automatic continuous positive airway pressure devices and noninvasive ventilators, are technologically complex and offer a considerable number of different modes of ventilation and setting options, the details of which are sometimes difficult to capture by the user. Therefore, better predicting and interpreting the actual performance of these ventilation devices in clinical application requires understanding their functioning principles and assessing their performance under well controlled bench test conditions with simulated patients. This concise review presents an updated perspective of the theoretical basis of intelligent continuous positive airway pressure and noninvasive ventilation devices, and of the tools available for assessing how these devices respond under specific ventilation phenotypes in patients requiring breathing support. PMID:27730162

Effects of ventilation on hearing loss in preterm neonates: Nasal continuous positive pressure does not increase the risk of hearing loss in ventilated neonates.

PubMed

Rastogi, Shantanu; Mikhael, Michel; Filipov, Panayot; Rastogi, Deepa

2013-03-01

There is increased risk of hearing loss in preterm neonates. This risk is further increased by environmental noise exposure especially from life support equipment such as ventilation. Nasal continuous positive airway pressure (NCPAP) used for respiratory support of preterm neonates is known to be associated with prolonged exposure to high levels of noise. However, there is paucity of information on the effect of NCPAP as compared to mechanical ventilation on hearing loss among preterm neonates. A retrospective chart review was performed on neonates with birth weight (BW) <1500g. Association of clinical factors including the use of NCPAP and mechanical ventilation with failure of hearing screen were studied. Those who failed hearing screen were followed for 2 years to observe long term effects of NCPAP on the hearing loss. Of 344 neonates included in the study, 61 failed hearing screen. Gestational age (p=0.008), BW (p=0.03), ventilation (p=0.02), intrauterine growth retardation (p=0.02), necrotizing enterocolitis (NEC) (p=0.02), apnea (p<0.001), use of vancomycin (p=0.01) and furosemide (p=0.01) were associated with failure of hearing screen. On multivariate analysis, ventilation (OR 4.56, p=0.02), apnea (OR 2.2, p<0.001) and NEC (OR 2.4, p=0.02) were predictors of failed hearing screen. As compared to those not ventilated, the odds of failing hearing screen was 4.53 (p<0.01) and 4.59 (p<0.01) for those treated with NCPAP and mechanical ventilation respectively, with there being no difference between these two ventilatory modalities. Of the 61 neonates, 42 were followed for 2 years, of which 19 had confirmed hearing loss. Among these 19 neonates, there was no difference (p=0.12) between those who were treated with NCPAP or with mechanical ventilation. There is no increase in the hearing loss in preterm neonates treated with NCPAP as compared to mechanical ventilation despite being exposed to higher environmental noise generated by the NCPAP. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Lung Volume Reduction Surgery for Respiratory Failure in Infants With Bronchopulmonary Dysplasia.

PubMed

Sohn, Bongyeon; Park, Samina; Park, In Kyu; Kim, Young Tae; Park, June Dong; Park, Sung-Hye; Kang, Chang Hyun

2018-04-01

Lung volume reduction surgery (LVRS) can be performed in patients with severe emphysematous disease. However, LVRS in pediatric patients has not yet been reported. Here, we report our experience with 2 cases of pediatric LVRS. The first patient was a preterm infant girl with severe bronchopulmonary dysplasia, pulmonary hypertension, and hypothyroidism. The emphysematous portion of the right lung was removed via sternotomy and right hemiclamshell incision. The patient was discharged on full-time home ventilator support for 3 months after the surgery. Since then, her respiratory function has improved continuously. She no longer needs oxygen supplementation or ventilator care. Her T-cannula was removed recently. The second patient was also a preterm infant girl with bronchopulmonary dysplasia. She was born with pulmonary hypertension and multiple congenital anomalies, including an atrial septal defect. Despite receiving the best supportive care, she could not be taken off the mechanical ventilator because of severe hypercapnia. We performed LVRS on the right lung via thoracotomy. She was successfully weaned off the mechanical ventilator 1 month after the surgery. She was discharged without severe complications at 3 months after the operation. At present, she is growing well with the help of intermittent home ventilator support. She can now tolerate an oral diet. Our experience shows that LVRS can be considered as a treatment option for pediatric patients with severe emphysematous lung. It is especially helpful for discontinuing prolonged mechanical ventilator care for patients with respiratory failure. Copyright © 2018 by the American Academy of Pediatrics.

A historical perspective on ventilator management.

PubMed

Shapiro, B A

1994-02-01

Paralysis via neuromuscular blockade in ICU patients requires mechanical ventilation. This review historically addresses the technological advances and scientific information upon which ventilatory management concepts are based, with special emphasis on the influence such concepts have had on the use of neuromuscular blocking agents. Specific reference is made to the scientific information and technological advances leading to the newer concepts of ventilatory management. Information from > 100 major studies in the peer-reviewed medical literature, along with the author's 25 yrs of clinical experience and academic involvement in acute respiratory care is presented. Nomenclature related to ventilatory management is specifically defined and consistently utilized to present and interpret the data. Pre-1970 ventilatory management is traced from the clinically unacceptable pressure-limited devices to the reliable performance of volume-limited ventilators. The scientific data and rationale that led to the concept of relatively large tidal volume delivery are reviewed in the light of today's concerns regarding alveolar overdistention, control-mode dyssynchrony, and auto-positive end-expiratory pressure. Also presented are the post-1970 scientific rationales for continuous positive airway pressure/positive end-expiratory pressure therapy, avoidance of alveolar hyperxia, and partial ventilatory support techniques (intermittent mandatory ventilation/synchronized intermittent mandatory ventilation). The development of pressure-support devices is discussed and the capability of pressure-control techniques is presented. The rationale for more recent concepts of total ventilatory support to avoid ventilator-induced lung injury is presented. The traditional techniques utilizing volume-preset ventilators with relatively large tidal volumes remain valid and desirable for the vast majority of patients requiring mechanical ventilation. Neuromuscular blockade is best avoided in these patients. However, adequate analgesia, amnesia, and sedation are required. For patients with severe lung disease, alveolar overdistention and hyperoxia should be avoided and may be best accomplished by total ventilatory support techniques, such as pressure control. Total ventilatory support requires neuromuscular blockade and may not provide eucapnic ventilation.

Mechanical ventilation alone, and in the presence sepsis, induces peripheral skeletal muscle catabolism in neonatal pigs

USDA-ARS?s Scientific Manuscript database

Reduced rates of skeletal muscle accretion are a prominent feature of the metabolic response to sepsis in infants and children. Septic neonates often require medical support with mechanical ventilation (MV). The combined effects of MV and sepsis in muscle have not been examined in neonates, in whom ...

Mechanical ventilation-associated lung fibrosis in acute respiratory distress syndrome: a significant contributor to poor outcome.

PubMed

Cabrera-Benitez, Nuria E; Laffey, John G; Parotto, Matteo; Spieth, Peter M; Villar, Jesús; Zhang, Haibo; Slutsky, Arthur S

2014-07-01

One of the most challenging problems in critical care medicine is the management of patients with the acute respiratory distress syndrome. Increasing evidence from experimental and clinical studies suggests that mechanical ventilation, which is necessary for life support in patients with acute respiratory distress syndrome, can cause lung fibrosis, which may significantly contribute to morbidity and mortality. The role of mechanical stress as an inciting factor for lung fibrosis versus its role in lung homeostasis and the restoration of normal pulmonary parenchymal architecture is poorly understood. In this review, the authors explore recent advances in the field of pulmonary fibrosis in the context of acute respiratory distress syndrome, concentrating on its relevance to the practice of mechanical ventilation, as commonly applied by anesthetists and intensivists. The authors focus the discussion on the thesis that mechanical ventilation-or more specifically, that ventilator-induced lung injury-may be a major contributor to lung fibrosis. The authors critically appraise possible mechanisms underlying the mechanical stress-induced lung fibrosis and highlight potential therapeutic strategies to mitigate this fibrosis.

Reflexology: its effects on physiological anxiety signs and sedation needs.

PubMed

Akin Korhan, Esra; Khorshid, Leyla; Uyar, Mehmet

2014-01-01

To investigate whether reflexology has an effect on the physiological signs of anxiety and level of sedation in patients receiving mechanically ventilated support, a single blinded, randomized controlled design with repeated measures was used in the intensive care unit of a university hospital in Turkey. Patients (n = 60) aged between 18 and 70 years and were hospitalized in the intensive care unit and receiving mechanically ventilated support. Participants were randomized to a control group or an intervention group. The latter received 30 minutes of reflexology therapy on their feet, hands, and ears for 5 days. Subjects had vital signs taken immediately before the intervention and at the 10th, 20th, and 30th minutes of the intervention. In the collection of the data, "American Association of Critical-Care Nurses Sedation Assessment Scale" was used. The reflexology therapy group had a significantly lower heart rate, systolic blood pressure, diastolic blood pressure, and respiratory rate than the control group. A statistically significant difference was found between the averages of the scores that the patients included in the experimental and control groups received from the agitation, anxiety, sleep, and patient-ventilator synchrony subscales of the American Association of Critical-Care Nurses Sedation Assessment Scale. Reflexology can serve as an effective method of decreasing the physiological signs of anxiety and the required level of sedation in patients receiving mechanically ventilated support. Nurses who have appropriate training and certification may include reflexology in routine care to reduce the physiological signs of anxiety of patients receiving mechanical ventilation.

The comparison of manual and LabVIEW-based fuzzy control on mechanical ventilation.

PubMed

Guler, Hasan; Ata, Fikret

2014-09-01

The aim of this article is to develop a knowledge-based therapy for management of rats with respiratory distress. A mechanical ventilator was designed to achieve this aim. The designed ventilator is called an intelligent mechanical ventilator since fuzzy logic was used to control the pneumatic equipment according to the rat's status. LabVIEW software was used to control all equipments in the ventilator prototype and to monitor respiratory variables in the experiment. The designed ventilator can be controlled both manually and by fuzzy logic. Eight female Wistar-Albino rats were used to test the designed ventilator and to show the effectiveness of fuzzy control over manual control on pressure control ventilation mode. The anesthetized rats were first ventilated for 20 min manually. After that time, they were ventilated for 20 min by fuzzy logic. Student's t-test for p < 0.05 was applied to the measured minimum, maximum and mean peak inspiration pressures to analyze the obtained results. The results show that there is no statistical difference in the rat's lung parameters before and after the experiments. It can be said that the designed ventilator and developed knowledge-based therapy support artificial respiration of living things successfully. © IMechE 2014.

Quantification of Age-Related Lung Tissue Mechanics under Mechanical Ventilation.

PubMed

Kim, JongWon; Heise, Rebecca L; Reynolds, Angela M; Pidaparti, Ramana M

2017-09-29

Elderly patients with obstructive lung diseases often receive mechanical ventilation to support their breathing and restore respiratory function. However, mechanical ventilation is known to increase the severity of ventilator-induced lung injury (VILI) in the elderly. Therefore, it is important to investigate the effects of aging to better understand the lung tissue mechanics to estimate the severity of ventilator-induced lung injuries. Two age-related geometric models involving human bronchioles from generation G10 to G23 and alveolar sacs were developed. The first is for a 50-year-old (normal) and second is for an 80-year old (aged) model. Lung tissue mechanics of normal and aged models were investigated under mechanical ventilation through computational simulations. Results obtained indicated that lung tissue strains during inhalation (t = 0.2 s) decreased by about 40% in the alveolar sac (G23) and 27% in the bronchiole (G20), respectively, for the 80-year-old as compared to the 50-year-old. The respiratory mechanics parameters (work of breathing per unit volume and maximum tissue strain) over G20 and G23 for the 80-year-old decreased by about 64% (three-fold) and 80% (four-fold), respectively, during the mechanical ventilation breathing cycle. However, there was a significant increase (by about threefold) in lung compliance for the 80-year-old in comparison to the 50-year-old. These findings from the computational simulations demonstrated that lung mechanical characteristics are significantly compromised in aging tissues, and these effects were quantified in this study.

Enhancing rehabilitation of mechanically ventilated patients in the intensive care unit: a quality improvement project.

PubMed

McWilliams, David; Weblin, Jonathan; Atkins, Gemma; Bion, Julian; Williams, Jenny; Elliott, Catherine; Whitehouse, Tony; Snelson, Catherine

2015-02-01

Prolonged periods of mechanical ventilation are associated with significant physical and psychosocial adverse effects. Despite increasing evidence supporting early rehabilitation strategies, uptake and delivery of such interventions in Europe have been variable. The objective of this study was to evaluate the impact of an early and enhanced rehabilitation program for mechanically ventilated patients in a large tertiary referral, mixed-population intensive care unit (ICU). A new supportive rehabilitation team was created within the ICU in April 2012, with a focus on promoting early and enhanced rehabilitation for patients at high risk for prolonged ICU and hospital stays. Baseline data on all patients invasively ventilated for at least 5 days in the previous 12 months (n = 290) were compared with all patients ventilated for at least 5 days in the 12 months after the introduction of the rehabilitation team (n = 292). The main outcome measures were mobility level at ICU discharge (assessed via the Manchester Mobility Score), mean ICU, and post-ICU length of stay (LOS), ventilator days, and in-hospital mortality. The introduction of the ICU rehabilitation team was associated with a significant increase in mobility at ICU discharge, and this was associated with a significant reduction in ICU LOS (16.9 vs 14.4 days, P = .007), ventilator days (11.7 vs 9.3 days, P < .05), total hospital LOS (35.3 vs 30.1 days, P < .001), and in-hospital mortality (39% vs 28%, P < .05). A quality improvement strategy to promote early and enhanced rehabilitation within this European ICU improved levels of mobility at critical care discharge, and this was associated with reduced ICU and hospital LOS and reduced days of mechanical ventilation. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Predicting the response of the injured lung to the mechanical breath profile

PubMed Central

Smith, Bradford J.; Lundblad, Lennart K. A.; Kollisch-Singule, Michaela; Satalin, Joshua; Nieman, Gary; Habashi, Nader

2015-01-01

Mechanical ventilation is a crucial component of the supportive care provided to patients with acute respiratory distress syndrome. Current practice stipulates the use of a low tidal volume (Vt) of 6 ml/kg ideal body weight, the presumptive notion being that this limits overdistension of the tissues and thus reduces volutrauma. We have recently found, however, that airway pressure release ventilation (APRV) is efficacious at preventing ventilator-induced lung injury, yet APRV has a very different mechanical breath profile compared with conventional low-Vt ventilation. To gain insight into the relative merits of these two ventilation modes, we measured lung mechanics and derecruitability in rats before and following Tween lavage. We fit to these lung mechanics measurements a computational model of the lung that accounts for both the degree of tissue distension of the open lung and the amount of lung derecruitment that takes place as a function of time. Using this model, we predicted how tissue distension, open lung fraction, and intratidal recruitment vary as a function of ventilator settings both for conventional low-Vt ventilation and for APRV. Our predictions indicate that APRV is more effective at recruiting the lung than low-Vt ventilation, but without causing more overdistension of the tissues. On the other hand, low-Vt ventilation generally produces less intratidal recruitment than APRV. Predictions such as these may be useful for deciding on the relative benefits of different ventilation modes and thus may serve as a means for determining how to ventilate a given lung in the least injurious fashion. PMID:25635004

New modes of assisted mechanical ventilation.

PubMed

Suarez-Sipmann, F

2014-05-01

Recent major advances in mechanical ventilation have resulted in new exciting modes of assisted ventilation. Compared to traditional ventilation modes such as assisted-controlled ventilation or pressure support ventilation, these new modes offer a number of physiological advantages derived from the improved patient control over the ventilator. By implementing advanced closed-loop control systems and using information on lung mechanics, respiratory muscle function and respiratory drive, these modes are specifically designed to improve patient-ventilator synchrony and reduce the work of breathing. Depending on their specific operational characteristics, these modes can assist spontaneous breathing efforts synchronically in time and magnitude, adapt to changing patient demands, implement automated weaning protocols, and introduce a more physiological variability in the breathing pattern. Clinicians have now the possibility to individualize and optimize ventilatory assistance during the complex transition from fully controlled to spontaneous assisted ventilation. The growing evidence of the physiological and clinical benefits of these new modes is favoring their progressive introduction into clinical practice. Future clinical trials should improve our understanding of these modes and help determine whether the claimed benefits result in better outcomes. Copyright © 2013 Elsevier España, S.L. and SEMICYUC. All rights reserved.

Model-based setting of inspiratory pressure and respiratory rate in pressure-controlled ventilation.

PubMed

Schranz, C; Becher, T; Schädler, D; Weiler, N; Möller, K

2014-03-01

Mechanical ventilation carries the risk of ventilator-induced-lung-injury (VILI). To minimize the risk of VILI, ventilator settings should be adapted to the individual patient properties. Mathematical models of respiratory mechanics are able to capture the individual physiological condition and can be used to derive personalized ventilator settings. This paper presents model-based calculations of inspiration pressure (pI), inspiration and expiration time (tI, tE) in pressure-controlled ventilation (PCV) and a retrospective evaluation of its results in a group of mechanically ventilated patients. Incorporating the identified first order model of respiratory mechanics in the basic equation of alveolar ventilation yielded a nonlinear relation between ventilation parameters during PCV. Given this patient-specific relation, optimized settings in terms of minimal pI and adequate tE can be obtained. We then retrospectively analyzed data from 16 ICU patients with mixed pathologies, whose ventilation had been previously optimized by ICU physicians with the goal of minimization of inspiration pressure, and compared the algorithm's 'optimized' settings to the settings that had been chosen by the physicians. The presented algorithm visualizes the patient-specific relations between inspiration pressure and inspiration time. The algorithm's calculated results highly correlate to the physician's ventilation settings with r = 0.975 for the inspiration pressure, and r = 0.902 for the inspiration time. The nonlinear patient-specific relations of ventilation parameters become transparent and support the determination of individualized ventilator settings according to therapeutic goals. Thus, the algorithm is feasible for a variety of ventilated ICU patients and has the potential of improving lung-protective ventilation by minimizing inspiratory pressures and by helping to avoid the build-up of clinically significant intrinsic positive end-expiratory pressure.

An Extracorporeal Artificial Placenta Supports Extremely Premature Lambs for One Week

PubMed Central

Bryner, Benjamin; Gray, Brian; Perkins, Elena; Davis, Ryan; Hoffman, Hayley; Barks, John; Owens, Gabe; Bocks, Martin; Rojas-Peña, Alvaro; Hirschl, Ronald; Bartlett, Robert; Mychaliska, George

2015-01-01

Purpose The treatment of extreme prematurity remains an unsolved problem. We developed an artificial placenta (AP) based on extracorporeal life support (ECLS) that simulates the intrauterine environment and provides gas exchange without mechanical ventilation (MV), and compared it to the current standard of neonatal care. Methods Extremely premature lambs (110-120d; term=145d) were used. AP lambs (n=9) were cannulated (jugular drainage, umbilical vein reinfusion) for ECLS .Control lambs (n=7) were intubated, ventilated, given surfactant, and transitioned to high-frequency oscillatory ventilation. All lambs received parenteral nutrition, antibiotics, and steroids. Hemodynamics, blood gases, hemoglobin, and circuit flows were measured. Results Four premature lambs survived for 1 week on the AP; one survived 6 days. Adequate oxygenation and ventilation were provided by the AP. The MV lambs survived 2-8 hours. Each of these lambs experienced a transient improvement with surfactant, but developed progressive hypercapnea and hypoxia despite high airway pressures and HFOV. Conclusions Extremely premature lambs were supported for 1 week with the AP with hemodynamic stability and adequate gas exchange; mechanically ventilated lambs succumbed within 8 hours. Further studies will assess control of fetal circulation and organ maturation on the AP. PMID:25598091

ARDS: challenges in patient care and frontiers in research.

PubMed

Bos, Lieuwe D; Martin-Loeches, Ignacio; Schultz, Marcus J

2018-03-31

This review discusses the clinical challenges associated with ventilatory support and pharmacological interventions in patients with acute respiratory distress syndrome (ARDS). In addition, it discusses current scientific challenges facing researchers when planning and performing trials of ventilatory support or pharmacological interventions in these patients.Noninvasive mechanical ventilation is used in some patients with ARDS. When intubated and mechanically ventilated, ARDS patients should be ventilated with low tidal volumes. A plateau pressure <30 cmH 2 O is recommended in all patients. It is suggested that a plateau pressure <15 cmH 2 O should be considered safe. Patient with moderate and severe ARDS should receive higher levels of positive end-expiratory pressure (PEEP). Rescue therapies include prone position and neuromuscular blocking agents. Extracorporeal support for decapneisation and oxygenation should only be considered when lung-protective ventilation is no longer possible, or in cases of refractory hypoxaemia, respectively. Tracheotomy is only recommended when prolonged mechanical ventilation is expected.Of all tested pharmacological interventions for ARDS, only treatment with steroids is considered to have benefit.Proper identification of phenotypes, known to respond differently to specific interventions, is increasingly considered important for clinical trials of interventions for ARDS. Such phenotypes could be defined based on clinical parameters, such as the arterial oxygen tension/inspiratory oxygen fraction ratio, but biological marker profiles could be more promising. Copyright ©ERS 2018.

The Association of Fever with Total Mechanical Ventilation Time in Critically Ill Patients.

PubMed

Park, Dong Won; Egi, Moritoki; Nishimura, Masaji; Chang, Youjin; Suh, Gee Young; Lim, Chae Man; Kim, Jae Yeol; Tada, Keiichi; Matsuo, Koichi; Takeda, Shinhiro; Tsuruta, Ryosuke; Yokoyama, Takeshi; Kim, Seon Ok; Koh, Younsuck

2016-12-01

This research aims to investigate the impact of fever on total mechanical ventilation time (TVT) in critically ill patients. Subgroup analysis was conducted using a previous prospective, multicenter observational study. We included mechanically ventilated patients for more than 24 hours from 10 Korean and 15 Japanese intensive care units (ICU), and recorded maximal body temperature under the support of mechanical ventilation (MAX(MV)). To assess the independent association of MAX(MV) with TVT, we used propensity-matched analysis in a total of 769 survived patients with medical or surgical admission, separately. Together with multiple linear regression analysis to evaluate the association between the severity of fever and TVT, the effect of MAX(MV) on ventilator-free days was also observed by quantile regression analysis in all subjects including non-survivors. After propensity score matching, a MAX(MV) ≥ 37.5°C was significantly associated with longer mean TVT by 5.4 days in medical admission, and by 1.2 days in surgical admission, compared to those with MAX(MV) of 36.5°C to 37.4°C. In multivariate linear regression analysis, patients with three categories of fever (MAX(MV) of 37.5°C to 38.4°C, 38.5°C to 39.4°C, and ≥ 39.5°C) sustained a significantly longer duration of TVT than those with normal range of MAX(MV) in both categories of ICU admission. A significant association between MAX(MV) and mechanical ventilator-free days was also observed in all enrolled subjects. Fever may be a detrimental factor to prolong TVT in mechanically ventilated patients. These findings suggest that fever in mechanically ventilated patients might be associated with worse mechanical ventilation outcome.

Impact of whole-body rehabilitation in patients receiving chronic mechanical ventilation.

PubMed

Martin, Ubaldo J; Hincapie, Luis; Nimchuk, Mark; Gaughan, John; Criner, Gerard J

2005-10-01

To evaluate the prevalence and magnitude of weakness in patients receiving chronic mechanical ventilation and the impact of providing aggressive whole-body rehabilitation on conventional weaning variables, muscle strength, and overall functional status. Retrospective analysis of 49 consecutive patients. Multidisciplinary ventilatory rehabilitation unit in an academic medical center. Forty-nine consecutive chronic ventilator-dependent patients referred to a tertiary care hospital ventilator rehabilitation unit. None. Patients were 58 +/- 7 yrs old with multiple etiologies for respiratory failure. On admission, all patients were bedridden and had severe weakness of upper and lower extremities measured by a 5-point muscle strength score and a 7-point Functional Independence Measurement. Postrehabilitation, patients had increases in upper and lower extremity strength (p < .05) and were able to stand and ambulate. All weaned from mechanical ventilation, but three required subsequent intermittent support. Six patients died before hospital discharge. Upper extremity strength on admission inversely correlated with time to wean from mechanical ventilation (R = .72, p < .001). : Patients receiving chronic ventilation are weak and deconditioned but respond to aggressive whole-body and respiratory muscle training with an improvement in strength, weaning outcome, and functional status. Whole-body rehabilitation should be considered a significant component of their therapy.

The effect of helium-oxygen-assisted mechanical ventilation on chronic obstructive pulmonary disease exacerbation: A systemic review and meta-analysis.

PubMed

Wu, Xu; Shao, Chuan; Zhang, Liang; Tu, Jinjing; Xu, Hui; Lin, Zhihui; Xu, Shuguang; Yu, Biyun; Tang, Yaodong; Li, Shanqun

2018-03-01

Chronic obstructive pulmonary disease (COPD) is often accompanied by acute exacerbations. Patients of COPD exacerbation suffering from respiratory failure often need the support of mechanical ventilation. Helium-oxygen can be used to reduce airway resistance during mechanical ventilation. The aim of this study is to evaluate the effect of helium-oxygen-assisted mechanical ventilation on COPD exacerbation through a meta-analysis. A comprehensive literature search through databases of Pub Med (1966∼2016), Ovid MEDLINE (1965∼2016), Cochrane EBM (1991∼2016), EMBASE (1974∼2016) and Ovid MEDLINE was performed to identify associated studies. Randomized clinical trials met our inclusion criteria that focus on helium-oxygen-assisted mechanical ventilation on COPD exacerbation were included. The quality of the papers was evaluated after inclusion and information was extracted for meta-analysis. Six articles and 392 patients were included in total. Meta-analysis revealed that helium-oxygen-assisted mechanical ventilation reduced Borg dyspnea scale and increased arterial PH compared with air-oxygen. No statistically significant difference was observed between helium-oxygen and air-oxygen as regards to WOB, PaCO 2 , OI, tracheal intubation rates and mortality within hospital. Our study suggests helium-oxygen-assisted mechanical ventilation can help to reduce Borg dyspnea scale. In terms of the tiny change of PH, its clinical benefit is negligible. There is no conclusive evidence indicating the beneficial effect of helium-oxygen-assisted mechanical ventilation on clinical outcomes or prognosis of COPD exacerbation. © 2017 John Wiley & Sons Ltd.

Automated Weaning from Mechanical Ventilation after Off-Pump Coronary Artery Bypass Grafting.

PubMed

Fot, Evgenia V; Izotova, Natalia N; Yudina, Angelika S; Smetkin, Aleksei A; Kuzkov, Vsevolod V; Kirov, Mikhail Y

2017-01-01

The discontinuation of mechanical ventilation after coronary surgery may prolong and significantly increase the load on intensive care unit personnel. We hypothesized that automated mode using INTELLiVENT-ASV can decrease duration of postoperative mechanical ventilation, reduce workload on medical staff, and provide safe ventilation after off-pump coronary artery bypass grafting (OPCAB). The primary endpoint of our study was to assess the duration of postoperative mechanical ventilation during different modes of weaning from respiratory support (RS) after OPCAB. The secondary endpoint was to assess safety of the automated weaning mode and the number of manual interventions to the ventilator settings during the weaning process in comparison with the protocolized weaning mode. Forty adult patients undergoing elective OPCAB were enrolled into a prospective single-center study. Patients were randomized into two groups: automated weaning ( n  = 20) using INTELLiVENT-ASV mode with quick-wean option; and protocolized weaning ( n  = 20), using conventional synchronized intermittent mandatory ventilation (SIMV) + pressure support (PS) mode. We assessed the duration of postoperative ventilation, incidence and duration of unacceptable RS, and the load on medical staff. We also performed the retrospective analysis of 102 patients (standard weaning) who were weaned from ventilator with SIMV + PS mode based on physician's experience without prearranged algorithm. Realization of the automated weaning protocol required change in respiratory settings in 2 patients vs. 7 (5-9) adjustments per patient in the protocolized weaning group. Both incidence and duration of unacceptable RS were reduced significantly by means of the automated weaning approach. The FiO 2 during spontaneous breathing trials was significantly lower in the automated weaning group: 30 (30-35) vs. 40 (40-45) % in the protocolized weaning group ( p  < 0.01). The average time until tracheal extubation did not differ in the automated weaning and the protocolized weaning groups: 193 (115-309) and 197 (158-253) min, respectively, but increased to 290 (210-411) min in the standard weaning group. The automated weaning system after off-pump coronary surgery might provide postoperative ventilation in a more protective way, reduces the workload on medical staff, and does not prolong the duration of weaning from ventilator. The use of automated or protocolized weaning can reduce the duration of postoperative mechanical ventilation in comparison with non-protocolized weaning based on the physician's decision.

The growing role of noninvasive ventilation in patients requiring prolonged mechanical ventilation.

PubMed

Hess, Dean R

2012-06-01

For many patients with chronic respiratory failure requiring ventilator support, noninvasive ventilation (NIV) is preferable to invasive support by tracheostomy. Currently available evidence does not support the use of nocturnal NIV in unselected patients with stable COPD. Several European studies have reported benefit for high intensity NIV, in which setting of inspiratory pressure and respiratory rate are selected to achieve normocapnia. There have also been studies reporting benefit for the use of NIV as an adjunct to exercise training. NIV may be useful as an adjunct to airway clearance techniques in patients with cystic fibrosis. Accumulating evidence supports the use of NIV in patients with obesity hypoventilation syndrome. There is considerable observational evidence supporting the use of NIV in patients with chronic respiratory failure related to neuromuscular disease, and one randomized controlled trial reported that the use of NIV was life-prolonging in patients with amyotrophic lateral sclerosis. A variety of interfaces can be used to provide NIV in patients with stable chronic respiratory failure. The mouthpiece is an interface that is unique in this patient population, and has been used with success in patients with neuromuscular disease. Bi-level pressure ventilators are commonly used for NIV, although there are now a new generation of intermediate ventilators that are portable, have a long battery life, and can be used for NIV and invasive applications. Pressure support ventilation, pressure controlled ventilation, and volume controlled ventilation have been used successfully for chronic applications of NIV. New modes have recently become available, but their benefits await evidence to support their widespread use. The success of NIV in a given patient population depends on selection of an appropriate patient, selection of an appropriate interface, selection of an appropriate ventilator and ventilator settings, the skills of the clinician, the motivation of the patient, and the support of the family. 2012 Daedalus Enterprises

Ventilatory changes during the use of heat and moisture exchangers in patients submitted to mechanical ventilation with support pressure and adjustments in ventilation parameters to compensate for these possible changes: a self-controlled intervention study in humans.

PubMed

Lucato, Jeanette Janaina Jaber; Cunha, Thiago Marraccini Nogueira da; Reis, Aline Mela Dos; Picanço, Patricia Salerno de Almeida; Barbosa, Renata Cléia Claudino; Liberali, Joyce; Righetti, Renato Fraga

2017-01-01

To evaluate the possible changes in tidal volume, minute volume and respiratory rate caused by the use of a heat and moisture exchanger in patients receiving pressure support mechanical ventilation and to quantify the variation in pressure support required to compensate for the effect caused by the heat and moisture exchanger. Patients under invasive mechanical ventilation in pressure support mode were evaluated using heated humidifiers and heat and moisture exchangers. If the volume found using the heat and moisture exchangers was lower than that found with the heated humidifier, an increase in pressure support was initiated during the use of the heat and moisture exchanger until a pressure support value was obtained that enabled the patient to generate a value close to the initial tidal volume obtained with the heated humidifier. The analysis was performed by means of the paired t test, and incremental values were expressed as percentages of increase required. A total of 26 patients were evaluated. The use of heat and moisture exchangers increased the respiratory rate and reduced the tidal and minute volumes compared with the use of the heated humidifier. Patients required a 38.13% increase in pressure support to maintain previous volumes when using the heat and moisture exchanger. The heat and moisture exchanger changed the tidal and minute volumes and respiratory rate parameters. Pressure support was increased to compensate for these changes.

Ventilatory changes during the use of heat and moisture exchangers in patients submitted to mechanical ventilation with support pressure and adjustments in ventilation parameters to compensate for these possible changes: a self-controlled intervention study in humans

PubMed Central

Lucato, Jeanette Janaina Jaber; da Cunha, Thiago Marraccini Nogueira; dos Reis, Aline Mela; Picanço, Patricia Salerno de Almeida; Barbosa, Renata Cléia Claudino; Liberali, Joyce; Righetti, Renato Fraga

2017-01-01

Objective To evaluate the possible changes in tidal volume, minute volume and respiratory rate caused by the use of a heat and moisture exchanger in patients receiving pressure support mechanical ventilation and to quantify the variation in pressure support required to compensate for the effect caused by the heat and moisture exchanger. Methods Patients under invasive mechanical ventilation in pressure support mode were evaluated using heated humidifiers and heat and moisture exchangers. If the volume found using the heat and moisture exchangers was lower than that found with the heated humidifier, an increase in pressure support was initiated during the use of the heat and moisture exchanger until a pressure support value was obtained that enabled the patient to generate a value close to the initial tidal volume obtained with the heated humidifier. The analysis was performed by means of the paired t test, and incremental values were expressed as percentages of increase required. Results A total of 26 patients were evaluated. The use of heat and moisture exchangers increased the respiratory rate and reduced the tidal and minute volumes compared with the use of the heated humidifier. Patients required a 38.13% increase in pressure support to maintain previous volumes when using the heat and moisture exchanger. Conclusion The heat and moisture exchanger changed the tidal and minute volumes and respiratory rate parameters. Pressure support was increased to compensate for these changes. PMID:28977257

Intraoperative mechanical ventilation: state of the art.

PubMed

Ball, Lorenzo; Costantino, Federico; Orefice, Giulia; Chandrapatham, Karthikka; Pelosi, Paolo

2017-10-01

Mechanical ventilation is a cornerstone of the intraoperative management of the surgical patient and is still mandatory in several surgical procedures. In the last decades, research focused on preventing postoperative pulmonary complications (PPCs), both improving risk stratification through the use of predictive scores and protecting the lung adopting so-called protective ventilation strategies. The aim of this review was to give an up-to-date overview of the currently suggested intraoperative ventilation strategies, along with their pathophysiologic rationale, with a focus on challenging conditions, such as obesity, one-lung ventilation and cardiopulmonary bypass. While anesthesia and mechanical ventilation are becoming increasingly safe practices, the contribution to surgical mortality attributable to postoperative lung injury is not negligible: for these reasons, the prevention of PPCs, including the use of protective mechanical ventilation is mandatory. Mechanical ventilation should be optimized providing an adequate respiratory support while minimizing unwanted negative effects. Due to the high number of surgical procedures performed daily, the impact on patients' health and healthcare costs can be relevant, even when new strategies result in an apparently small improvement of outcome. A protective intraoperative ventilation should include a low tidal volume of 6-8 mL/kg of predicted body weight, plateau pressures ideally below 16 cmH2O, the lowest possible driving pressure, moderate-low PEEP levels except in obese patients, laparoscopy and long surgical procedures that might benefit of a slightly higher PEEP. The work of the anesthesiologist should start with a careful preoperative visit to assess the risk, and a close postoperative monitoring.

Dynamic airway pressure-time curve profile (Stress Index): a systematic review.

PubMed

Terragni, Pierpaolo; Bussone, Guido; Mascia, Luciana

2016-01-01

The assessment of respiratory mechanics at the bedside is necessary in order to identify the most protective ventilatory strategy. Indeed in the last 20 years, adverse effects of positive ventilation to the lung structures have led to a reappraisal of the objectives of mechanical ventilation. The ventilator setting requires repeated readjustment over the period of mechanical ventilation dependency and careful respiratory monitoring to minimize the risks, preventing further injury and permitting the lung and airways healing. Among the different methods that have been proposed and validated, the analysis of dynamic P-t curve (named Stress Index, SI) represents an adequate tool available at the bedside, repeatable and, therefore, able to identify the amount of overdistension occurring in the daily clinical practice, when modifying positive end-expiratory pressure. In this review we will analyze the evidence that supports respiratory mechanics assessment at the bedside and the application of the dynamic P/t curve profile (SI) to optimize protective ventilation in patients with acute respiratory failure.

Preemptive mechanical ventilation can block progressive acute lung injury.

PubMed

Sadowitz, Benjamin; Jain, Sumeet; Kollisch-Singule, Michaela; Satalin, Joshua; Andrews, Penny; Habashi, Nader; Gatto, Louis A; Nieman, Gary

2016-02-04

Mortality from acute respiratory distress syndrome (ARDS) remains unacceptable, approaching 45% in certain high-risk patient populations. Treating fulminant ARDS is currently relegated to supportive care measures only. Thus, the best treatment for ARDS may lie with preventing this syndrome from ever occurring. Clinical studies were examined to determine why ARDS has remained resistant to treatment over the past several decades. In addition, both basic science and clinical studies were examined to determine the impact that early, protective mechanical ventilation may have on preventing the development of ARDS in at-risk patients. Fulminant ARDS is highly resistant to both pharmacologic treatment and methods of mechanical ventilation. However, ARDS is a progressive disease with an early treatment window that can be exploited. In particular, protective mechanical ventilation initiated before the onset of lung injury can prevent the progression to ARDS. Airway pressure release ventilation (APRV) is a novel mechanical ventilation strategy for delivering a protective breath that has been shown to block progressive acute lung injury (ALI) and prevent ALI from progressing to ARDS. ARDS mortality currently remains as high as 45% in some studies. As ARDS is a progressive disease, the key to treatment lies with preventing the disease from ever occurring while it remains subclinical. Early protective mechanical ventilation with APRV appears to offer substantial benefit in this regard and may be the prophylactic treatment of choice for preventing ARDS.

Preemptive mechanical ventilation can block progressive acute lung injury

PubMed Central

Sadowitz, Benjamin; Jain, Sumeet; Kollisch-Singule, Michaela; Satalin, Joshua; Andrews, Penny; Habashi, Nader; Gatto, Louis A; Nieman, Gary

2016-01-01

Mortality from acute respiratory distress syndrome (ARDS) remains unacceptable, approaching 45% in certain high-risk patient populations. Treating fulminant ARDS is currently relegated to supportive care measures only. Thus, the best treatment for ARDS may lie with preventing this syndrome from ever occurring. Clinical studies were examined to determine why ARDS has remained resistant to treatment over the past several decades. In addition, both basic science and clinical studies were examined to determine the impact that early, protective mechanical ventilation may have on preventing the development of ARDS in at-risk patients. Fulminant ARDS is highly resistant to both pharmacologic treatment and methods of mechanical ventilation. However, ARDS is a progressive disease with an early treatment window that can be exploited. In particular, protective mechanical ventilation initiated before the onset of lung injury can prevent the progression to ARDS. Airway pressure release ventilation (APRV) is a novel mechanical ventilation strategy for delivering a protective breath that has been shown to block progressive acute lung injury (ALI) and prevent ALI from progressing to ARDS. ARDS mortality currently remains as high as 45% in some studies. As ARDS is a progressive disease, the key to treatment lies with preventing the disease from ever occurring while it remains subclinical. Early protective mechanical ventilation with APRV appears to offer substantial benefit in this regard and may be the prophylactic treatment of choice for preventing ARDS. PMID:26855896

Interactive simulation system for artificial ventilation on the internet: virtual ventilator.

PubMed

Takeuchi, Akihiro; Abe, Tadashi; Hirose, Minoru; Kamioka, Koichi; Hamada, Atsushi; Ikeda, Noriaki

2004-12-01

To develop an interactive simulation system "virtual ventilator" that demonstrates the dynamics of pressure and flow in the respiratory system under the combination of spontaneous breathing, ventilation modes, and ventilator options. The simulation system was designed to be used by unexperienced health care professionals as a self-training tool. The system consists of a simulation controller and three modules: respiratory, spontaneous breath, and ventilator. The respiratory module models the respiratory system by three resistances representing the main airway, the right and left lungs, and two compliances also representing the right and left lungs. The spontaneous breath module generates inspiratory negative pressure produced by a patient. The ventilator module generates driving force of pressure or flow according to the combination of the ventilation mode and options. These forces are given to the respiratory module through the simulation controller. The simulation system was developed using HTML, VBScript (3000 lines, 100 kB) and ActiveX control (120 kB), and runs on Internet Explorer (5.5 or higher). The spontaneous breath is defined by a frequency, amplitude and inspiratory patterns in the spontaneous breath module. The user can construct a ventilation mode by setting a control variable, phase variables (trigger, limit, and cycle), and options. Available ventilation modes are: controlled mechanical ventilation (CMV), continuous positive airway pressure, synchronized intermittent mandatory ventilation (SIMV), pressure support ventilation (PSV), SIMV + PSV, pressure-controlled ventilation (PCV), pressure-regulated volume control (PRVC), proportional assisted ventilation, mandatory minute ventilation (MMV), bilevel positive airway pressure (BiPAP). The simulation system demonstrates in a graph and animation the airway pressure, flow, and volume of the respiratory system during mechanical ventilation both with and without spontaneous breathing. We developed a web application that demonstrated the respiratory mechanics and the basic theory of ventilation mode.

Randomized prospective crossover study of biphasic intermittent positive airway pressure ventilation (BIPAP) versus pressure support ventilation (PSV) in surgical intensive care patients.

PubMed

Elrazek, E Abd

2004-10-01

The aim of this prospective, randomized and crossover study was to assess the role of a relatively new mode of mechanical ventilation, biphasic intermittent positive airway pressure (BIPAP) in comparison to another well established one, pressure-support ventilation (PSV) in surgical intensive care patients. 24 generally stable patients, breathing on their own after short-term (< 24 hours) postoperative controlled mechanical ventilation (CMV) were randomized to start on either PSV or BIPAP, and indirect calorimetry measurements were performed after 1 hour adaptation period at two time intervals; immediately after the investigated ventilatory mode was started and 1 hour later. Statistics included a two-tailed paired t-test to compare the two sets of different data, p < 0.5 was considered significant. Oxygen consumption (VO2), energy expenditure (EE), Carbon dioxide production (VCO2), and respiratory quotient (RQ) did not differ significantly between the two groups. There were also no significant differences regarding respiratory rate (RR), minute volume (MV) and arterial blood gas analysis (ABGs). Both modes of ventilation were well tolerated by all patients. PSV and BIPAP can be used for weaning patients comfortably in surgical intensive care after short-term postoperative ventilation. BIPAP may have the credit of being smoother than PSV where no patient effort is required.

Automatic control of pressure support for ventilator weaning in surgical intensive care patients.

PubMed

Schädler, Dirk; Engel, Christoph; Elke, Gunnar; Pulletz, Sven; Haake, Nils; Frerichs, Inéz; Zick, Günther; Scholz, Jens; Weiler, Norbert

2012-03-15

Despite its ability to reduce overall ventilation time, protocol-guided weaning from mechanical ventilation is not routinely used in daily clinical practice. Clinical implementation of weaning protocols could be facilitated by integration of knowledge-based, closed-loop controlled protocols into respirators. To determine whether automated weaning decreases overall ventilation time compared with weaning based on a standardized written protocol in an unselected surgical patient population. In this prospective controlled trial patients ventilated for longer than 9 hours were randomly allocated to receive either weaning with automatic control of pressure support ventilation (automated-weaning group) or weaning based on a standardized written protocol (control group) using the same ventilation mode. The primary end point of the study was overall ventilation time. Overall ventilation time (median [25th and 75th percentile]) did not significantly differ between the automated-weaning (31 [19-101] h; n = 150) and control groups (39 [20-118] h; n = 150; P = 0.178). Patients who underwent cardiac surgery (n = 132) exhibited significantly shorter overall ventilation times in the automated-weaning (24 [18-57] h) than in the control group (35 [20-93] h; P = 0.035). The automated-weaning group exhibited shorter ventilation times until the first spontaneous breathing trial (1 [0-15] vs. 9 [1-51] h; P = 0.001) and a trend toward fewer tracheostomies (17 vs. 28; P = 0.075). Overall ventilation times did not significantly differ between weaning using automatic control of pressure support ventilation and weaning based on a standardized written protocol. Patients after cardiac surgery may benefit from automated weaning. Implementation of additional control variables besides the level of pressure support may further improve automated-weaning systems. Clinical trial registered with www.clinicaltrials.gov (NCT 00445289).

Oral care intervention to reduce incidence of ventilator-associated pneumonia in the neurologic intensive care unit.

PubMed

Fields, Lorraine B

2008-10-01

Ventilator-associated pneumonia (VAP) is a preventable secondary consequence of intubation and mechanical ventilation. VAP is pneumonia that develops in an intubated patient after 48 hours or more of mechanical ventilator support. Mechanically ventilated patients in neurologic and other intensive care units (ICUs) are at an increased risk of VAP due to factors such as decreased level of consciousness; dry, open mouth; and microaspiration of secretions. VAP can be prevented by initiating interventions from the Institute of Healthcare Improvement's VAP bundle, including (a) elevating the head of the bed of ventilated patients to 30 degrees, (b) preventing venous thromboembolism through use of sequential compression devices or anticoagulation, (c) administering gastric acid histamine2 blockers, (d) practicing good hand hygiene, (e) initiating early mobilization, and (f) performing daily sedation interruption at 10 am to evaluate neurologic status. The one intervention not included in the IHI bundle is oral hygiene. The purpose of this project is to support the premise that oral care, including timed toothbrushing, combined with the VAP bundle can mitigate and prevent the occurrence of VAP. Our project specifically addressed timed oral care of mechanically ventilated patients on a 24-bed stroke, neurologic, and medical ICU. Patients were randomized into a control group that performed usual oral care or an intervention group that brushed teeth every 8 hours. The results were immediate and startling, as the VAP rate dropped to zero within a week of beginning the every-8-hours toothbrushing regimen in the intervention group. The study was so successful that the control group was dropped after 6 months, and all intubated patients' teeth were brushed every 8 hours, maintaining the zero rate until the end of the study.

Music preferences of mechanically ventilated patients participating in a randomized controlled trial.

PubMed

Heiderscheit, Annie; Breckenridge, Stephanie J; Chlan, Linda L; Savik, Kay

2014-01-01

Mechanical ventilation (MV) is a life-saving measure and supportive modality utilized to treat patients experiencing respiratory failure. Patients experience pain, discomfort, and anxiety as a result of being mechanically ventilated. Music listening is a non-pharmacological intervention used to manage these psychophysiological symptoms associated with mechanical ventilation. The purpose of this secondary analysis was to examine music preferences of 107 MV patients enrolled in a randomized clinical trial that implemented a patient-directed music listening protocol to help manage the psychophysiological symptom of anxiety. Music data presented includes the music genres and instrumentation patients identified as their preferred music. Genres preferred include: classical, jazz, rock, country, and oldies. Instrumentation preferred include: piano, voice, guitar, music with nature sounds, and orchestral music. Analysis of three patients' preferred music received throughout the course of the study is illustrated to demonstrate the complexity of assessing MV patients and the need for an ongoing assessment process.

Music preferences of mechanically ventilated patients participating in a randomized controlled trial

PubMed Central

Heiderscheit, Annie; Breckenridge, Stephanie J.; Chlan, Linda L.; Savik, Kay

2014-01-01

Mechanical ventilation (MV) is a life-saving measure and supportive modality utilized to treat patients experiencing respiratory failure. Patients experience pain, discomfort, and anxiety as a result of being mechanically ventilated. Music listening is a non-pharmacological intervention used to manage these psychophysiological symptoms associated with mechanical ventilation. The purpose of this secondary analysis was to examine music preferences of 107 MV patients enrolled in a randomized clinical trial that implemented a patient-directed music listening protocol to help manage the psychophysiological symptom of anxiety. Music data presented includes the music genres and instrumentation patients identified as their preferred music. Genres preferred include: classical, jazz, rock, country, and oldies. Instrumentation preferred include: piano, voice, guitar, music with nature sounds, and orchestral music. Analysis of three patients’ preferred music received throughout the course of the study is illustrated to demonstrate the complexity of assessing MV patients and the need for an ongoing assessment process. PMID:25574992

Nursing diagnoses in patients having mechanical ventilation support in a respiratory intensive care unit in Turkey.

PubMed

Yücel, Şebnem Çinar; Eşer, Ismet; Güler, Elem Kocaçal; Khorshid, Leyla

2011-10-01

This research was carried out to find out the nursing diagnoses in patients who have mechanical ventilation support in a respiratory intensive care unit. The study was conducted with 51 evaluations of critically ill adult patients who underwent invasive and non-invasive mechanical ventilation therapy in 2008. Data collection was based on Gordon's 11 Functional Health Patterns, and nursing diagnoses were determined according to North American Nursing Diagnosis Association-International (NANDA-I) Taxonomy II. The nursing diagnoses were determined by two researchers separately. The consistency between the nursing diagnoses defined by the two researchers was evaluated by using Cohen's kappa (κ). Forty men (78.4%) and 11 women (21.6%) whose mean ages were 70.19 (SD = 8.96) years were included in the study. Nineteen subgroups of nursing diagnoses about safety/protection domain, and 15 subgroups about activity/rest domain were seen at different rates in the patients. There was a statistically significant difference between mechanical ventilation via tracheostomy or endotracheal tube and decreased cardiac output (d.f. = 1, χ(2) = 4.760, P = 0.029). The relationship between the length of time under mechanical ventilation and impaired physical mobility was considerably significant (d.f. = 3, χ(2) = 24.459, P = 0.000). It was found out that there was a high degree of agreement (96.8%) between the nursing diagnoses defined by the two researchers separately (κ = 0.936, SE = 0.08). © 2011 Blackwell Publishing Asia Pty Ltd.

A miniature mechanical ventilator for newborn mice.

PubMed

Kolandaivelu, K; Poon, C S

1998-02-01

Transgenic/knockout mice with pre-defined mutations have become increasingly popular in biomedical research as models of human diseases. In some instances, the resulting mutation may cause cardiorespiratory distress in the neonatal or adult animals and may necessitate resuscitation. Here we describe the design and testing of a miniature and versatile ventilator that can deliver varying ventilatory support modes, including conventional mechanical ventilation and high-frequency ventilation, to animals as small as the newborn mouse. With a double-piston body chamber design, the device circumvents the problem of air leakage and obviates the need for invasive procedures such as endotracheal intubation, which are particularly important in ventilating small animals. Preliminary tests on newborn mice as early as postnatal day O demonstrated satisfactory restoration of pulmonary ventilation and the prevention of respiratory failure in mutant mice that are prone to respiratory depression. This device may prove useful in the postnatal management of transgenic/knockout mice with genetically inflicted respiratory disorders.

Effect of Ventilation Support on Oxidative Stress and Ischemia-Modified Albumin in Neonates.

PubMed

Dursun, Arzu; Okumuş, Nurullah; Erol, Sara; Bayrak, Tülin; Zenciroğlu, Ayşegül

2016-01-01

Mechanical ventilation (MV) can induce oxidative stress, which plays a critical role in pulmonary injury in intubated neonates. Ischemia-modified albumin (IMA)-a variant of human serum albumin-is a novel biomarker of myocardial ischemia that occurs due to reactive oxygen species during ischemic insult. This study aimed to investigate IMA production due to oxidative stress induced during MV in neonates. This study included 17 neonates that were ventilated using synchronized intermittent mechanical ventilation (SIMV; SIMV group) and 20 neonates ventilated using continuous positive airway pressure (CPAP; CPAP group). Blood samples were collected from each neonate during ventilation support and following cessation of ventilation support. Total antioxidant capacity (TAC) and total oxidant status (TOS) were measured using the Erel method. IMA was measured via an enzyme-linked immunosorbent assay kit (Cusabio Biotech Co., Ltd., Wuhan, China). The oxidant stress index (OSI) was calculated as OSI = TOS/TAC. Statistical analysis was performed using SPSS v.18.0 (SPSS Inc., Chicago, IL) for Windows. Among the neonates included in the study, mean gestational age was 34.7 ± 3.8 weeks, mean birth weight was 2,553 ± 904 g, and 54% were premature. There were not any significant differences in mean gestational age or birth weight between the SIMV and CPAP groups. Among the neonates in both the groups, mean IMA, TOS, and OSI levels were significantly higher during ventilation support (102.2 ± 9.3 IU mL(-1), 15.5 ± 1.3 µmol H2O2 equivalent L(-1), and 0.85 ± 0.22 arbitrary units [ABU], respectively), as compared with following cessation of ventilation support (82.9 ± 11.9 IU mL(-1), 13.4 ± 1.3 µmol H2O2 equivalent L(-1), and 0.64 ± 0.14 ABU, respectively) (p = 0.001). Among all the neonates in the study, mean TAC was significantly lower during ventilation support than the postventilation support (1.82 ± 0.28 mmol 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid [Trolox] equivalent L(-1) vs. 2.16 ± 0.31 mmol Trolox equivalent L(-1)) (p = 0.001). There were no significant differences in mean TAC, OSI, or IMA levels between the SIMV and CPAP groups. The mean TOS level during ventilation support and the mean difference in TOS between during and postventilation support was significantly greater in the CPAP group than in the SIMV group. There were no significant relationships between the mean TOS, TAC, OSI, or IMA levels, and gestational age of the neonates. SIMV and CPAP activated the oxidative stress and increased the IMA level in neonates; therefore, measurement of IMA and oxidant markers may be useful in the follow-up of lung injury in neonates due to ventilation support. Additional prospective studies are needed to compare the effects of various ventilation methods on oxidative stress and the IMA level in neonates. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Challenges on non-invasive ventilation to treat acute respiratory failure in the elderly.

PubMed

Scala, Raffaele

2016-11-15

Acute respiratory failure is a frequent complication in elderly patients especially if suffering from chronic cardio-pulmonary diseases. Non-invasive mechanical ventilation constitutes a successful therapeutic tool in the elderly as, like in younger patients, it is able to prevent endotracheal intubation in a wide range of acute conditions; moreover, this ventilator technique is largely applied in the elderly in whom invasive mechanical ventilation is considered not appropriated. Furthermore, the integration of new technological devices, ethical issues and environment of treatment are still largely debated in the treatment of acute respiratory failure in the elderly.This review aims at reporting and critically analyzing the peculiarities in the management of acute respiratory failure in elderly people, the role of noninvasive mechanical ventilation, the potential advantages of applying alternative or integrated therapeutic tools (i.e. high-flow nasal cannula oxygen therapy, non-invasive and invasive cough assist devices and low-flow carbon-dioxide extracorporeal systems), drawbacks in physician's communication and "end of life" decisions. As several areas of this topic are not supported by evidence-based data, this report takes in account also "real-life" data as well as author's experience.The choice of the setting and of the timing of non-invasive mechanical ventilation in elderly people with advanced cardiopulmonary disease should be carefully evaluated together with the chance of using integrated or alternative supportive devices. Last but not least, economic and ethical issues may often challenges the behavior of the physicians towards elderly people who are hospitalized for acute respiratory failure at the end stage of their cardiopulmonary and neoplastic diseases.

Mechanical ventilation in patients subjected to extracorporeal membrane oxygenation (ECMO).

PubMed

López Sanchez, M

2017-11-01

Mechanical ventilation (MV) is a crucial element in the management of acute respiratory distress syndrome (ARDS), because there is high level evidence that a low tidal volume of 6ml/kg (protective ventilation) improves survival. In these patients with refractory respiratory insufficiency, venovenous extracorporeal membrane oxygenation (ECMO) can be used. This salvage technique improves oxygenation, promotes CO 2 clearance, and facilitates protective and ultraprotective MV, potentially minimizing ventilation-induced lung injury. Although numerous trials have investigated different ventilation strategies in patients with ARDS, consensus is lacking on the optimal MV settings during venovenous ECMO. Although the concept of "lung rest" was introduced years ago, there are no evidence-based guidelines on its use in application to MV in patients supported by ECMO. How MV in ECMO patients can promote lung recovery and weaning from ventilation is not clear. The purpose of this review is to describe the ventilation strategies used during venovenous ECMO in clinical practice. Copyright © 2017 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Mathematics of Ventilator-induced Lung Injury.

PubMed

Rahaman, Ubaidur

2017-08-01

Ventilator-induced lung injury (VILI) results from mechanical disruption of blood-gas barrier and consequent edema and releases of inflammatory mediators. A transpulmonary pressure (P L ) of 17 cmH 2 O increases baby lung volume to its anatomical limit, predisposing to VILI. Viscoelastic property of lung makes pulmonary mechanics time dependent so that stress (P L ) increases with respiratory rate. Alveolar inhomogeneity in acute respiratory distress syndrome acts as a stress riser, multiplying global stress at regional level experienced by baby lung. Limitation of stress (P L ) rather than strain (tidal volume [V T ]) is the safe strategy of mechanical ventilation to prevent VILI. Driving pressure is the noninvasive surrogate of lung strain, but its relations to P L is dependent on the chest wall compliance. Determinants of lung stress (V T , driving pressure, positive end-expiratory pressure, and inspiratory flow) can be quantified in terms of mechanical power, and a safe threshold can be determined, which can be used in decision-making between safe mechanical ventilation and extracorporeal lung support.

Mechanical ventilation weaning and extubation after spinal cord injury: a Western Trauma Association multicenter study.

PubMed

Kornblith, Lucy Z; Kutcher, Matthew E; Callcut, Rachael A; Redick, Brittney J; Hu, Charles K; Cogbill, Thomas H; Baker, Christopher C; Shapiro, Mark L; Burlew, Clay C; Kaups, Krista L; DeMoya, Marc A; Haan, James M; Koontz, Christopher H; Zolin, Samuel J; Gordy, Stephanie D; Shatz, David V; Paul, Doug B; Cohen, Mitchell J

2013-12-01

Respiratory failure after acute spinal cord injury (SCI) is well recognized, but data defining which patients need long-term ventilator support and criteria for weaning and extubation are lacking. We hypothesized that many patients with SCI, even those with cervical SCI, can be successfully managed without long-term mechanical ventilation and its associated morbidity. Under the auspices of the Western Trauma Association Multi-Center Trials Group, a retrospective study of patients with SCI at 14 major trauma centers was conducted. Comprehensive injury, demographic, and outcome data on patients with acute SCI were compiled. The primary outcome variable was the need for mechanical ventilation at discharge. Secondary outcomes included the use of tracheostomy and development of acute lung injury and ventilator-associated pneumonia. A total of 360 patients had SCI requiring mechanical ventilation. Sixteen patients were excluded for death within the first 2 days of hospitalization. Of the 344 patients included, 222 (64.5%) had cervical SCI. Notably, 62.6% of the patients with cervical SCI were ventilator free by discharge. One hundred forty-nine patients (43.3%) underwent tracheostomy, and 53.7% of them were successfully weaned from the ventilator, compared with an 85.6% success rate among those with no tracheostomy (p < 0.05). Patients who underwent tracheostomy had significantly higher rates of ventilator-associated pneumonia (61.1% vs. 20.5%, p < 0.05) and acute lung injury (12.8% vs. 3.6%, p < 0.05) and fewer ventilator-free days (1 vs. 24 p < 0.05). When controlled for injury severity, thoracic injury, and respiratory comorbidities, tracheostomy after cervical SCI was an independent predictor of ventilator dependence with an associated 14-fold higher likelihood of prolonged mechanical ventilation (odds ratio, 14.1; 95% confidence interval, 2.78-71.67; p < 0.05). While many patients with SCI require short-term mechanical ventilation, the majority can be successfully weaned before discharge. In patients with SCI, tracheostomy is associated with major morbidity, and its use, especially among patients with cervical SCI, deserves further study. Prognostic study, level III.

Variability in Usual Care Mechanical Ventilation for Pediatric Acute Respiratory Distress Syndrome: Time for a Decision Support Protocol?

PubMed

Newth, Christopher J L; Sward, Katherine A; Khemani, Robinder G; Page, Kent; Meert, Kathleen L; Carcillo, Joseph A; Shanley, Thomas P; Moler, Frank W; Pollack, Murray M; Dalton, Heidi J; Wessel, David L; Berger, John T; Berg, Robert A; Harrison, Rick E; Holubkov, Richard; Doctor, Allan; Dean, J Michael; Jenkins, Tammara L; Nicholson, Carol E

2017-11-01

Although pediatric intensivists philosophically embrace lung protective ventilation for acute lung injury and acute respiratory distress syndrome, we hypothesized that ventilator management varies. We assessed ventilator management by evaluating changes to ventilator settings in response to blood gases, pulse oximetry, or end-tidal CO2. We also assessed the potential impact that a pediatric mechanical ventilation protocol adapted from National Heart Lung and Blood Institute acute respiratory distress syndrome network protocols could have on reducing variability by comparing actual changes in ventilator settings to those recommended by the protocol. Prospective observational study. Eight tertiary care U.S. PICUs, October 2011 to April 2012. One hundred twenty patients (age range 17 d to 18 yr) with acute lung injury/acute respiratory distress syndrome. Two thousand hundred arterial and capillary blood gases, 3,964 oxygen saturation by pulse oximetry, and 2,757 end-tidal CO2 values were associated with 3,983 ventilator settings. Ventilation mode at study onset was pressure control 60%, volume control 19%, pressure-regulated volume control 18%, and high-frequency oscillatory ventilation 3%. Clinicians changed FIO2 by ±5 or ±10% increments every 8 hours. Positive end-expiratory pressure was limited at ~10 cm H2O as oxygenation worsened, lower than would have been recommended by the protocol. In the first 72 hours of mechanical ventilation, maximum tidal volume/kg using predicted versus actual body weight was 10.3 (8.5-12.9) (median [interquartile range]) versus 9.2 mL/kg (7.6-12.0) (p < 0.001). Intensivists made changes similar to protocol recommendations 29% of the time, opposite to the protocol's recommendation 12% of the time and no changes 56% of the time. Ventilator management varies substantially in children with acute respiratory distress syndrome. Opportunities exist to minimize variability and potentially injurious ventilator settings by using a pediatric mechanical ventilation protocol offering adequately explicit instructions for given clinical situations. An accepted protocol could also reduce confounding by mechanical ventilation management in a clinical trial.

Respiratory support in oncology ward setting: a prospective descriptive study.

PubMed

Mishra, Seema; Bhatnagar, Sushma; Gupta, Deepak; Goyal, Gaurav Nirvani; Agrawal, Ravi; Jain, Roopesh; Chauhan, Himanshu

2009-01-01

Mechanical ventilation in cancer patients is a critical issue The present prospective descriptive study was designed (1) to assess the patient population needing respirator support in ward setting at a premier state-run oncology institute in India, (2) to observe and analyze the course of their disease while on respirator, and (3) to coordinate better quality of life measures in cancer patients at the institute based on the present study's outcomes. Beginning from March 2005 to March 2006, all cancer patients who were connected to respirator in the wards were enrolled in the current study. Our anesthesiology department at the cancer institute also has primary responsibility for airway management and mechanical ventilation in high dependency units of oncology wards. Preventilation variables in cancer patients were assessed to judge the futility of mechanical ventilation in ward setting. Subsequently, patients were observed for disease course while on respirator. Final outcome with its etio-pathogenesis was correlated with predicted futility of mechanical ventilation. Over a period of 1 year, 132 (46 men and 86 women) cancer patients with median age 40 years (range 1-75 years) were connected to respirator in oncology wards. Based on the preventilation variables and indications for respirator support, right prediction of medical futility and hospital discharge was made in 77% of patients. Underestimation and overestimation of survival to hospital discharge was made in 10% cases and 13% cases, respectively. Based on preventilation variables, prediction of outcome in cancer patients needing respirator support can be made in 77% cases. This high probability of prediction can be used to educate patients, and their families and primary physicians, for well-informed and documented advance directives, formulated and regularly revised DNAR policies, and judicious use of respirator support for better quality-of-life outcomes.

Linking lung function to structural damage of alveolar epithelium in ventilator-induced lung injury.

PubMed

Hamlington, Katharine L; Smith, Bradford J; Dunn, Celia M; Charlebois, Chantel M; Roy, Gregory S; Bates, Jason H T

2018-05-06

Understanding how the mechanisms of ventilator-induced lung injury (VILI), namely atelectrauma and volutrauma, contribute to the failure of the blood-gas barrier and subsequent intrusion of edematous fluid into the airspace is essential for the design of mechanical ventilation strategies that minimize VILI. We ventilated mice with different combinations of tidal volume and positive end-expiratory pressure (PEEP) and linked degradation in lung function measurements to injury of the alveolar epithelium observed via scanning electron microscopy. Ventilating with both high inspiratory plateau pressure and zero PEEP was necessary to cause derangements in lung function as well as visually apparent physical damage to the alveolar epithelium of initially healthy mice. In particular, the epithelial injury was tightly associated with indicators of alveolar collapse. These results support the hypothesis that mechanical damage to the epithelium during VILI is at least partially attributed to atelectrauma-induced damage of alveolar type I epithelial cells. Copyright © 2018. Published by Elsevier B.V.

Complementary home mechanical ventilation techniques. SEPAR Year 2014.

PubMed

Chiner, Eusebi; Sancho-Chust, José N; Landete, Pedro; Senent, Cristina; Gómez-Merino, Elia

2014-12-01

This is a review of the different complementary techniques that are useful for optimizing home mechanical ventilation (HMV). Airway clearance is very important in patients with HMV and many patients, particularly those with reduced peak cough flow, require airway clearance (manual or assisted) or assisted cough techniques (manual or mechanical) and suctioning procedures, in addition to ventilation. In the case of invasive HMV, good tracheostomy cannula management is essential for success. HMV patients may have sleep disturbances that must be taken into account. Sleep studies including complete polysomnography or respiratory polygraphy are helpful for identifying patient-ventilator asynchrony. Other techniques, such as bronchoscopy or nutritional support, may be required in patients on HMV, particularly if percutaneous gastrostomy is required. Information on treatment efficacy can be obtained from HMV monitoring, using methods such as pulse oximetry, capnography or the internal programs of the ventilators themselves. Finally, the importance of the patient's subjective perception is reviewed, as this may potentially affect the success of the HMV. Copyright © 2014 SEPAR. Published by Elsevier Espana. All rights reserved.

Severity of illness and outcome in adult patients with primary varicella pneumonia.

PubMed

Gregorakos, Leonidas; Myrianthefs, Pavlos; Markou, Nikolaos; Chroni, Despina; Sakagianni, Ekaterini

2002-01-01

Varicella pneumonia is a serious complication of primary varicella infection in adults that often results in respiratory failure and death. To analyze the clinical and laboratory manifestations of primary varicella pneumonia in patients admitted to our intensive care unit (ICU). Retrospective study on patients treated in our ICU with a diagnosis of primary varicella pneumonia during a period of 15 years. We recorded age, gender, smoking habits, clinical and laboratory findings, arterial blood gases, chest radiograph, illness severity (SAPS II), length of stay, necessity for mechanical ventilation, complications, therapy and survival. We examined the influence of the duration of respiratory symptoms and rash prior to admission, and the influence of illness severity on outcome. There was a statistically significant difference in duration of respiratory symptoms, duration of rash and SAPS II on admission between: (a) mechanically ventilated patients vs. spontaneously breathing patients (p < 0.007, p < 0.00, p < 0.00), (b) patients who survived vs. patients with poor outcome (p < 0.001, p < 0.000, p < 0.000), and (c) mechanically ventilated patients with poor outcome vs. mechanically ventilated patients who survived (p < 0.001, p < 0.00, p < 0.000). Overall mortality was 13.6%; death occurred only in mechanically ventilated patients (mortality 33.3%). Primary varicella pneumonia remains a critical problem with significant mortality. When recognized before respiratory failure ensues and mechanical ventilation becomes mandatory, patients could have an excellent outcome. Adult patients who delay asking for medical support, the disease may lead to the need for mechanical ventilation and severe complications with a fatal outcome. Copyright 2002 S. Karger AG, Basel

AT1 receptor blocker losartan protects against mechanical ventilation-induced diaphragmatic dysfunction

PubMed Central

Kwon, Oh Sung; Smuder, Ashley J.; Wiggs, Michael P.; Hall, Stephanie E.; Sollanek, Kurt J.; Morton, Aaron B.; Talbert, Erin E.; Toklu, Hale Z.; Tumer, Nihal

2015-01-01

Mechanical ventilation is a life-saving intervention for patients in respiratory failure. Unfortunately, prolonged ventilator support results in diaphragmatic atrophy and contractile dysfunction leading to diaphragm weakness, which is predicted to contribute to problems in weaning patients from the ventilator. While it is established that ventilator-induced oxidative stress is required for the development of ventilator-induced diaphragm weakness, the signaling pathway(s) that trigger oxidant production remain unknown. However, recent evidence reveals that increased plasma levels of angiotensin II (ANG II) result in oxidative stress and atrophy in limb skeletal muscles. Using a well-established animal model of mechanical ventilation, we tested the hypothesis that increased circulating levels of ANG II are required for both ventilator-induced diaphragmatic oxidative stress and diaphragm weakness. Cause and effect was determined by administering an angiotensin-converting enzyme inhibitor (enalapril) to prevent ventilator-induced increases in plasma ANG II levels, and the ANG II type 1 receptor antagonist (losartan) was provided to prevent the activation of ANG II type 1 receptors. Enalapril prevented the increase in plasma ANG II levels but did not protect against ventilator-induced diaphragmatic oxidative stress or diaphragm weakness. In contrast, losartan attenuated both ventilator-induced oxidative stress and diaphragm weakness. These findings indicate that circulating ANG II is not essential for the development of ventilator-induced diaphragm weakness but that activation of ANG II type 1 receptors appears to be a requirement for ventilator-induced diaphragm weakness. Importantly, these experiments provide the first evidence that the Food and Drug Administration-approved drug losartan may have clinical benefits to protect against ventilator-induced diaphragm weakness in humans. PMID:26359481

Acetazolamide: a second wind for a respiratory stimulant in the intensive care unit?

PubMed

Heming, Nicholas; Urien, Saïk; Faisy, Christophe

2012-08-07

Patients with chronic obstructive pulmonary disease (COPD) are affected by episodes of respiratory exacerbations, some of which can be severe and may necessitate respiratory support. Prolonged invasive mechanical ventilation is associated with increased mortality rates. Persistent failure to discontinue invasive mechanical ventilation is a major issue in patients with COPD. Pure or mixed metabolic alkalosis is a common finding in the intensive care unit (ICU) and is associated with a worse outcome. In patients with COPD, the condition is called post-hypercapnic alkalosis and is a complication of mechanical ventilation. Reversal of metabolic alkalosis may facilitate weaning from mechanical ventilation of patients with COPD. Acetazolamide, a non-specific carbonic anhydrase inhibitor, is one of the drugs employed in the ICU to reverse metabolic alkalosis. The drug is relatively safe, undesirable effects being rare. The compartmentalization of the different isoforms of the carbonic anhydrase enzyme may, in part, explain the lack of evidence of the efficacy of acetazolamide as a respiratory stimulant. Recent findings suggest that the usually employed doses of acetazolamide in the ICU may be insufficient to significantly improve respiratory parameters in mechanically ventilated patients with COPD. Randomized controlled trials using adequate doses of acetazolamide are required to address this issue.

Modes of mechanical ventilation for the operating room.

PubMed

Ball, Lorenzo; Dameri, Maddalena; Pelosi, Paolo

2015-09-01

Most patients undergoing surgical procedures need to be mechanically ventilated, because of the impact of several drugs administered at induction and during maintenance of general anaesthesia on respiratory function. Optimization of intraoperative mechanical ventilation can reduce the incidence of post-operative pulmonary complications and improve the patient's outcome. Preoxygenation at induction of general anaesthesia prolongs the time window for safe intubation, reducing the risk of hypoxia and overweighs the potential risk of reabsorption atelectasis. Non-invasive positive pressure ventilation delivered through different interfaces should be considered at the induction of anaesthesia morbidly obese patients. Anaesthesia ventilators are becoming increasingly sophisticated, integrating many functions that were once exclusive to intensive care. Modern anaesthesia machines provide high performances in delivering the desired volumes and pressures accurately and precisely, including assisted ventilation modes. Therefore, the physicians should be familiar with the potential and pitfalls of the most commonly used intraoperative ventilation modes: volume-controlled, pressure-controlled, dual-controlled and assisted ventilation. Although there is no clear evidence to support the advantage of any one of these ventilation modes over the others, protective mechanical ventilation with low tidal volume and low levels of positive end-expiratory pressure (PEEP) should be considered in patients undergoing surgery. The target tidal volume should be calculated based on the predicted or ideal body weight rather than on the actual body weight. To optimize ventilation monitoring, anaesthesia machines should include end-inspiratory and end-expiratory pause as well as flow-volume loop curves. The routine administration of high PEEP levels should be avoided, as this may lead to haemodynamic impairment and fluid overload. Higher PEEP might be considered during surgery longer than 3 h, laparoscopy in the Trendelenburg position and in patients with body mass index >35 kg/m(2). Large randomized trials are warranted to identify subgroups of patients and the type of surgery that can potentially benefit from specific ventilation modes or ventilation settings. Copyright © 2015 Elsevier Ltd. All rights reserved.

Early High-Frequency Oscillatory Ventilation in Pediatric Acute Respiratory Failure. A Propensity Score Analysis.

PubMed

Bateman, Scot T; Borasino, Santiago; Asaro, Lisa A; Cheifetz, Ira M; Diane, Shelley; Wypij, David; Curley, Martha A Q

2016-03-01

The use of high-frequency oscillatory ventilation (HFOV) for acute respiratory failure in children is prevalent despite the lack of efficacy data. To compare the outcomes of patients with acute respiratory failure managed with HFOV within 24-48 hours of endotracheal intubation with those receiving conventional mechanical ventilation (CMV) and/or late HFOV. This is a secondary analysis of data from the RESTORE (Randomized Evaluation of Sedation Titration for Respiratory Failure) study, a prospective cluster randomized clinical trial conducted between 2009 and 2013 in 31 U.S. pediatric intensive care units. Propensity score analysis, including degree of hypoxia in the model, compared the duration of mechanical ventilation and mortality of patients treated with early HFOV matched with those treated with CMV/late HFOV. Among 2,449 subjects enrolled in RESTORE, 353 patients (14%) were ever supported on HFOV, of which 210 (59%) had HFOV initiated within 24-48 hours of intubation. The propensity score model predicting the probability of receiving early HFOV included 1,064 patients (181 early HFOV vs. 883 CMV/late HFOV) with significant hypoxia (oxygenation index ≥ 8). The degree of hypoxia was the most significant contributor to the propensity score model. After adjusting for risk category, early HFOV use was associated with a longer duration of mechanical ventilation (hazard ratio, 0.75; 95% confidence interval, 0.64-0.89; P = 0.001) but not with mortality (odds ratio, 1.28; 95% confidence interval, 0.92-1.79; P = 0.15) compared with CMV/late HFOV. In adjusted models including important oxygenation variables, early HFOV was associated with a longer duration of mechanical ventilation. These analyses make supporting the current approach to HFOV less convincing.

Brazilian recommendations of mechanical ventilation 2013. Part 2

PubMed Central

2014-01-01

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document. PMID:25410835

Brazilian recommendations of mechanical ventilation 2013. Part I

PubMed Central

Barbas, Carmen Sílvia Valente; Ísola, Alexandre Marini; Farias, Augusto Manoel de Carvalho; Cavalcanti, Alexandre Biasi; Gama, Ana Maria Casati; Duarte, Antonio Carlos Magalhães; Vianna, Arthur; Serpa, Ary; Bravim, Bruno de Arruda; Pinheiro, Bruno do Valle; Mazza, Bruno Franco; de Carvalho, Carlos Roberto Ribeiro; Toufen, Carlos; David, Cid Marcos Nascimento; Taniguchi, Corine; Mazza, Débora Dutra da Silveira; Dragosavac, Desanka; Toledo, Diogo Oliveira; Costa, Eduardo Leite; Caser, Eliana Bernardete; Silva, Eliezer; Amorim, Fabio Ferreira; Saddy, Felipe; Galas, Filomena Regina Barbosa Gomes; Silva, Gisele Sampaio; de Matos, Gustavo Faissol Janot; Emmerich, João Claudio; Valiatti, Jorge Luis dos Santos; Teles, José Mario Meira; Victorino, Josué Almeida; Ferreira, Juliana Carvalho; Prodomo, Luciana Passuello do Vale; Hajjar, Ludhmila Abrahão; Martins, Luiz Cláudio; Malbouisson, Luiz Marcelo Sá; Vargas, Mara Ambrosina de Oliveira; Reis, Marco Antonio Soares; Amato, Marcelo Brito Passos; Holanda, Marcelo Alcântara; Park, Marcelo; Jacomelli, Marcia; Tavares, Marcos; Damasceno, Marta Cristina Paulette; Assunção, Murillo Santucci César; Damasceno, Moyzes Pinto Coelho Duarte; Youssef, Nazah Cherif Mohamad; Teixeira, Paulo José Zimmermann; Caruso, Pedro; Duarte, Péricles Almeida Delfino; Messeder, Octavio; Eid, Raquel Caserta; Rodrigues, Ricardo Goulart; de Jesus, Rodrigo Francisco; Kairalla, Ronaldo Adib; Justino, Sandra; Nemer, Sérgio Nogueira; Romero, Simone Barbosa; Amado, Verônica Moreira

2014-01-01

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document. PMID:25028944

Brazilian recommendations of mechanical ventilation 2013. Part 2

PubMed Central

Barbas, Carmen Sílvia Valente; Ísola, Alexandre Marini; Farias, Augusto Manoel de Carvalho; Cavalcanti, Alexandre Biasi; Gama, Ana Maria Casati; Duarte, Antonio Carlos Magalhães; Vianna, Arthur; Serpa Neto, Ary; Bravim, Bruno de Arruda; Pinheiro, Bruno do Valle; Mazza, Bruno Franco; de Carvalho, Carlos Roberto Ribeiro; Toufen Júnior, Carlos; David, Cid Marcos Nascimento; Taniguchi, Corine; Mazza, Débora Dutra da Silveira; Dragosavac, Desanka; Toledo, Diogo Oliveira; Costa, Eduardo Leite; Caser, Eliana Bernadete; Silva, Eliezer; Amorim, Fabio Ferreira; Saddy, Felipe; Galas, Filomena Regina Barbosa Gomes; Silva, Gisele Sampaio; de Matos, Gustavo Faissol Janot; Emmerich, João Claudio; Valiatti, Jorge Luis dos Santos; Teles, José Mario Meira; Victorino, Josué Almeida; Ferreira, Juliana Carvalho; Prodomo, Luciana Passuello do Vale; Hajjar, Ludhmila Abrahão; Martins, Luiz Claudio; Malbouisson, Luis Marcelo Sá; Vargas, Mara Ambrosina de Oliveira; Reis, Marco Antonio Soares; Amato, Marcelo Brito Passos; Holanda, Marcelo Alcântara; Park, Marcelo; Jacomelli, Marcia; Tavares, Marcos; Damasceno, Marta Cristina Paulette; Assunção, Murillo Santucci César; Damasceno, Moyzes Pinto Coelho Duarte; Youssef, Nazah Cherif Mohamed; Teixeira, Paulo José Zimmermann; Caruso, Pedro; Duarte, Péricles Almeida Delfino; Messeder, Octavio; Eid, Raquel Caserta; Rodrigues, Ricardo Goulart; de Jesus, Rodrigo Francisco; Kairalla, Ronaldo Adib; Justino, Sandra; Nemer, Sergio Nogueira; Romero, Simone Barbosa; Amado, Verônica Moreira

2014-01-01

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document. PMID:25295817

Brazilian recommendations of mechanical ventilation 2013. Part I

PubMed Central

2014-01-01

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document. PMID:25210957

Application of mid-frequency ventilation in an animal model of lung injury: a pilot study.

PubMed

Mireles-Cabodevila, Eduardo; Chatburn, Robert L; Thurman, Tracy L; Zabala, Luis M; Holt, Shirley J; Swearingen, Christopher J; Heulitt, Mark J

2014-11-01

Mid-frequency ventilation (MFV) is a mode of pressure control ventilation based on an optimal targeting scheme that maximizes alveolar ventilation and minimizes tidal volume (VT). This study was designed to compare the effects of conventional mechanical ventilation using a lung-protective strategy with MFV in a porcine model of lung injury. Our hypothesis was that MFV can maximize ventilation at higher frequencies without adverse consequences. We compared ventilation and hemodynamic outcomes between conventional ventilation and MFV. This was a prospective study of 6 live Yorkshire pigs (10 ± 0.5 kg). The animals were subjected to lung injury induced by saline lavage and injurious conventional mechanical ventilation. Baseline conventional pressure control continuous mandatory ventilation was applied with V(T) = 6 mL/kg and PEEP determined using a decremental PEEP trial. A manual decision support algorithm was used to implement MFV using the same conventional ventilator. We measured P(aCO2), P(aO2), end-tidal carbon dioxide, cardiac output, arterial and venous blood oxygen saturation, pulmonary and systemic vascular pressures, and lactic acid. The MFV algorithm produced the same minute ventilation as conventional ventilation but with lower V(T) (-1 ± 0.7 mL/kg) and higher frequency (32.1 ± 6.8 vs 55.7 ± 15.8 breaths/min, P < .002). There were no differences between conventional ventilation and MFV for mean airway pressures (16.1 ± 1.3 vs 16.4 ± 2 cm H2O, P = .75) even when auto-PEEP was higher (0.6 ± 0.9 vs 2.4 ± 1.1 cm H2O, P = .02). There were no significant differences in any hemodynamic measurements, although heart rate was higher during MFV. In this pilot study, we demonstrate that MFV allows the use of higher breathing frequencies and lower V(T) than conventional ventilation to maximize alveolar ventilation. We describe the ventilatory or hemodynamic effects of MFV. We also demonstrate that the application of a decision support algorithm to manage MFV is feasible. Copyright © 2014 by Daedalus Enterprises.

Assessing Patient and Caregiver Intent to Use Mobile Device Videoconferencing for Remote Mechanically-Ventilated Patient Management

ERIC Educational Resources Information Center

Smith, Brian R.

2017-01-01

The Michigan Medicine adult Assisted Ventilation Clinic (AVC) supports patients with neuromuscular disorders and spinal cord injuries and their caregivers at home, helping them avoid expensive emergency department visits, hospitalization, and unnecessary or excessive treatments. Mobile device videoconferencing provides an effective capability for…

Outcome of Concurrent Occult Hemothorax and Pneumothorax in Trauma Patients Who Required Assisted Ventilation

PubMed Central

Mahmood, Ismail; Tawfeek, Zainab; El-Menyar, Ayman; Zarour, Ahmad; Afifi, Ibrahim; Kumar, Suresh; Latifi, Rifat; Al-Thani, Hassan

2015-01-01

Background. The management and outcomes of occult hemopneumothorax in blunt trauma patients who required mechanical ventilation are not well studied. We aimed to study patients with occult hemopneumothorax on mechanical ventilation who could be carefully managed without tube thoracostomy. Methods. Chest trauma patients with occult hemopneumothorax who were on mechanical ventilation were prospectively evaluated. The presence of hemopneumothorax was confirmed by CT scanning. Hospital length of stay, complications, and outcome were recorded. Results. A total of 56 chest trauma patients with occult hemopneumothorax who were on ventilatory support were included with a mean age of 36 ± 13 years. Hemopneumothorax was managed conservatively in 72% cases and 28% underwent tube thoracostomy as indicated. 29% of patients developed pneumonia, 16% had Acute Respiratory Distress Syndrome (ARDS), and 7% died. Thickness of hemothorax, duration of mechanical ventilation, and development of ARDS were significantly associated with tube thoracostomy in comparison to no-chest tube group. Conclusions. The majority of occult hemopneumothorax can be carefully managed without tube thoracostomy in patients who required positive pressure ventilation. Tube thoracotomy could be restricted to those who had evidence of increase in the size of the hemothorax or pneumothorax on follow-up chest radiographs or developed respiratory compromise. PMID:25785199

Differences in mortality based on worsening ratio of partial pressure of oxygen to fraction of inspired oxygen corrected for immune system status and respiratory support.

PubMed

Miles, Lachlan F; Bailey, Michael; Young, Paul; Pilcher, David V

2012-03-01

To define the relationship between worsening oxygenation status (worst PaO(2)/FiO(2) ratio in the first 24 hours after intensive care unit admission) and mortality in immunosuppressed and immunocompetent ICU patients in the presence and absence of mechanical ventilation. Retrospective cohort study. Data were extracted from the Australian and New Zealand Intensive Care Society Adult Patient Database. Adult patients admitted to 129 ICUs in Australasia, 2000-2010. In hospital and ICU mortality; relationship between mortality and declining PaO(2)/FiO(2) ratio by ventilation status and immune status. 457 750 patient records were analysed. Worsening oxygenation status was associated with increasing mortality in all groups. Higher mortality was seen in immunosuppressed patients than immunocompetent patients. After multivariate analysis, in mechanically ventilated patients, declining PaO(2)/FiO(2) ratio in the first 24 hours of ICU admission was associated with a more rapidly rising mortality rate in immunosuppressed patients than non-immunosuppressed patients. Immunosuppression did not affect the relationship between oxygenation status and mortality in non-ventilated patients. Immunosuppression increases the risk of mortality with progressively worsening oxygenation status, but only in the presence of mechanical ventilation. Further research into the impact of mechanical ventilation in immunosuppressed patients is required.

[Role of noninvasive mechanical ventilation in patients with severe avian influenza A (H7N9) complicated with acute respiratory distress syndrome].

PubMed

Luo, Haili; Wang, Shaohong; Shen, Feng; Yuan, Tongmei; Pan, Xianguo; Liu, Jingtao; Yao, Ling; Wu, Juncheng; Long, Xuemei

2018-05-01

Human infection with avian influenza A (H7N9) is an acute contagious respiratory disease. Acute respiratory distress syndrome (ARDS) is a common complication in patients with severe avian influenza A (H7N9), for whom mechanical ventilation (MV) is an important supportive method. A patient, suffered from severe avian influenza A (H7N9) and complicated with ARDS, was admitted to the Second Affiliated Hospital of Guizhou Medical University in January 2017. With very intensive care for oxygenation, respiration and consciousness, and monitoring, she was successfully cured by comprehensive managements, among which noninvasive mechanical ventilation (NIV) was the major respiratory support method. The result demonstrate that, in patients with conscious state, satisfied expectoration ability and relatively good cooperation, and with close observation of oxygenation and respiratory rate, NIV may be accepted as an effective method for patient with ARDS caused by severe avian influenza A (H7N9).

A new system for continuous and remote monitoring of patients receiving home mechanical ventilation

NASA Astrophysics Data System (ADS)

Battista, L.

2016-09-01

Home mechanical ventilation is the treatment of patients with respiratory failure or insufficiency by means of a mechanical ventilator at a patient's home. In order to allow remote patient monitoring, several tele-monitoring systems have been introduced in the last few years. However, most of them usually do not allow real-time services, as they have their own proprietary communication protocol implemented and some ventilation parameters are not always measured. Moreover, they monitor only some breaths during the whole day, despite the fact that a patient's respiratory state may change continuously during the day. In order to reduce the above drawbacks, this work reports the development of a novel remote monitoring system for long-term, home-based ventilation therapy; the proposed system allows for continuous monitoring of the main physical quantities involved during home-care ventilation (e.g., differential pressure, volume, and air flow rate) and is developed in order to allow observations of different remote therapy units located in different places of a city, region, or country. The developed remote patient monitoring system is able to detect various clinical events (e.g., events of tube disconnection and sleep apnea events) and has been successfully tested by means of experimental tests carried out with pulmonary ventilators typically used to support sick patients.

A new system for continuous and remote monitoring of patients receiving home mechanical ventilation.

PubMed

Battista, L

2016-09-01

Home mechanical ventilation is the treatment of patients with respiratory failure or insufficiency by means of a mechanical ventilator at a patient's home. In order to allow remote patient monitoring, several tele-monitoring systems have been introduced in the last few years. However, most of them usually do not allow real-time services, as they have their own proprietary communication protocol implemented and some ventilation parameters are not always measured. Moreover, they monitor only some breaths during the whole day, despite the fact that a patient's respiratory state may change continuously during the day. In order to reduce the above drawbacks, this work reports the development of a novel remote monitoring system for long-term, home-based ventilation therapy; the proposed system allows for continuous monitoring of the main physical quantities involved during home-care ventilation (e.g., differential pressure, volume, and air flow rate) and is developed in order to allow observations of different remote therapy units located in different places of a city, region, or country. The developed remote patient monitoring system is able to detect various clinical events (e.g., events of tube disconnection and sleep apnea events) and has been successfully tested by means of experimental tests carried out with pulmonary ventilators typically used to support sick patients.

Respiratory system mechanics in acute respiratory distress syndrome.

PubMed

Kallet, Richard H; Katz, Jeffrey A

2003-09-01

Respiratory mechanics research is important to the advancement of ARDS management. Twenty-eight years ago, research on the effects of PEEP and VT indicated that the lungs of ARDS patients did not behave in a manner consistent with homogenously distributed lung injury. Both Suter and colleagues] and Katz and colleagues reported that oxygenation continued to improve as PEEP increased (suggesting lung recruitment), even though static Crs decreased and dead-space ventilation increased (suggesting concurrent lung overdistension). This research strongly suggested that without VT reduction, the favorable effects of PEEP on lung recruitment are offset by lung overdistension at end-inspiration. The implications of these studies were not fully appreciated at that time, in part because the concept of ventilator-associated lung injury was in its nascent state. Ten years later. Gattinoni and colleagues compared measurements of static pressure-volume curves with FRC and CT scans of the chest in ARDS. They found that although PEEP recruits collapsed (primarily dorsal) lung segments, it simultaneously causes overdistension of non-dependent, inflated lung regions. Furthermore, the specific compliance of the aerated, residually healthy lung tissue is essentially normal. The main implication of these findings is that traditional mechanical ventilation practice was injecting excessive volumes of gas into functionally small lungs. Therefore, the emblematic low static Crs measured in ARDS reflects not only surface tension phenomena and recruitment of collapsed airspaces but also overdistension of the remaining healthy lung. The studies reviewed in this article support the concept that lung injury in ARDS is heterogeneously distributed, with resulting disparate mechanical stresses, and indicate the additional complexity from alterations in chest wall mechanics. Most of these studies, however, were published before lung-protective ventilation. Therefore, further studies are needed to refine the understanding of the mechanical effects of lung-protective ventilation. Although low-VT ventilation is becoming a standard of care for ARDS patients, many issues remain unresolved; among them are the role of PEEP and recruitment maneuvers in either preventing or promoting lung injury and the effects of respiratory rate and graded VT reduction on mechanical stress in the lungs. The authors believe that advances in mechanical ventilation that may further improve patient outcomes are likely to come from more sophisticated monitoring capabilities (ie, the ability to measure P1 or perhaps Cslice) than from the creation of new modes of ventilatory support.

Effect of leak and breathing pattern on the accuracy of tidal volume estimation by commercial home ventilators: a bench study.

PubMed

Luján, Manel; Sogo, Ana; Pomares, Xavier; Monsó, Eduard; Sales, Bernat; Blanch, Lluís

2013-05-01

New home ventilators are able to provide clinicians data of interest through built-in software. Monitoring of tidal volume (VT) is a key point in the assessment of the efficacy of home mechanical ventilation. To assess the reliability of the VT provided by 5 ventilators in a bench test. Five commercial ventilators from 4 different manufacturers were tested in pressure support mode with the help of a breathing simulator under different conditions of mechanical respiratory pattern, inflation pressure, and intentional leakage. Values provided by the built-in software of each ventilator were compared breath to breath with the VT monitored through an external pneumotachograph. Ten breaths for each condition were compared for every tested situation. All tested ventilators underestimated VT (ranges of -21.7 mL to -83.5 mL, which corresponded to -3.6% to -14.7% of the externally measured VT). A direct relationship between leak and underestimation was found in 4 ventilators, with higher underestimations of the VT when the leakage increased, ranging between -2.27% and -5.42% for each 10 L/min increase in the leakage. A ventilator that included an algorithm that computes the pressure loss through the tube as a function of the flow exiting the ventilator had the minimal effect of leaks on the estimation of VT (0.3%). In 3 ventilators the underestimation was also influenced by mechanical pattern (lower underestimation with restrictive, and higher with obstructive). The inclusion of algorithms that calculate the pressure loss as a function of the flow exiting the ventilator in commercial models may increase the reliability of VT estimation.

High-frequency oscillatory ventilation in ALI/ARDS.

PubMed

Ali, Sammy; Ferguson, Niall D

2011-07-01

In the last 2 decades, our goals for mechanical ventilatory support in patients with acute respiratory distress syndrome (ARDS) or acute lung injury (ALI) have changed dramatically. Several randomized controlled trials have built on a substantial body of preclinical work to demonstrate that the way in which we employ mechanical ventilation has an impact on important patient outcomes. Avoiding ventilator-induced lung injury (VILI) is now a major focus when clinicians are considering which ventilatory strategy to employ in patients with ALI/ARDS. Physicians are searching for methods that may further limit VILI, while still achieving adequate gas exchange. Copyright © 2011 Elsevier Inc. All rights reserved.

Multicenter review of diaphragm pacing in spinal cord injury: successful not only in weaning from ventilators but also in bridging to independent respiration.

PubMed

Posluszny, Joseph A; Onders, Raymond; Kerwin, Andrew J; Weinstein, Michael S; Stein, Deborah M; Knight, Jennifer; Lottenberg, Lawrence; Cheatham, Michael L; Khansarinia, Saeid; Dayal, Saraswati; Byers, Patricia M; Diebel, Lawrence

2014-02-01

Ventilator-dependent spinal cord-injured (SCI) patients require significant resources related to ventilator dependence. Diaphragm pacing (DP) has been shown to successfully replace mechanical ventilators for chronic ventilator-dependent tetraplegics. Early use of DP following SCI has not been described. Here, we report our multicenter review experience with the use of DP in the initial hospitalization after SCI. Under institutional review board approval for humanitarian use device, we retrospectively reviewed our multicenter nonrandomized interventional protocol of laparoscopic diaphragm motor point mapping with electrode implantation and subsequent diaphragm conditioning and ventilator weaning. Twenty-nine patients with an average age of 31 years (range, 17-65 years) with only two females were identified. Mechanism of injury included motor vehicle collision (7), diving (6), gunshot wounds (4), falls (4), athletic injuries (3), bicycle collision (2), heavy object falling on spine (2), and motorcycle collision (1). Elapsed time from injury to surgery was 40 days (range, 3-112 days). Seven (24%) of the 29 patients who were evaluated for the DP placement had nonstimulatable diaphragms from either phrenic nerve damage or infarction of the involved phrenic motor neurons and were not implanted. Of the stimulatable patients undergoing DP, 72% (16 of 22) were completely free of ventilator support in an average of 10.2 days. For the remaining six DP patients, two had delayed weans of 180 days, three had partial weans using DP at times during the day, and one patient successfully implanted went to a long-term acute care hospital and subsequently had life-prolonging measures withdrawn. Eight patients (36%) had complete recovery of respiration, and DP wires were removed. Early laparoscopic diaphragm mapping and DP implantation can successfully wean traumatic cervical SCI patients from ventilator support. Early laparoscopic mapping is also diagnostic in that a nonstimulatable diaphragm is a convincing evidence of an inability to wean from ventilator support, and long-term ventilator management can be immediately instituted. Therapeutic study, level V.

Outcome of critically ill allogeneic hematopoietic stem-cell transplantation recipients: a reappraisal of indications for organ failure supports.

PubMed

Pène, Frédéric; Aubron, Cécile; Azoulay, Elie; Blot, François; Thiéry, Guillaume; Raynard, Bruno; Schlemmer, Benoît; Nitenberg, Gérard; Buzyn, Agnès; Arnaud, Philippe; Socié, Gérard; Mira, Jean-Paul

2006-02-01

Because the overall outcome of critically ill hematologic patients has improved, we evaluated the short-term and long-term outcomes of the poor risk subgroup of allogeneic hematopoietic stem-cell transplantation (HSCT) recipients requiring admission to the intensive care unit (ICU). This was a retrospective multicenter study of allogeneic HSCT recipients admitted to the ICU between 1997 and 2003. Two hundred nine critically ill allogeneic HSCT recipients were included in the study. Admission in the ICU occurred during the engraftment period (< or = 30 days after transplantation) for 70 of the patients and after the engraftment period for 139 patients. The overall in-ICU, in-hospital, 6-month, and 1-year survival rates were 48.3%, 32.5%, 27.2%, and 21%, respectively. Mechanical ventilation was required in 122 patients and led to a dramatic decrease in survival rates, resulting in in-ICU, in-hospital, 6-month, and 1-year survival rates of 18%, 15.6%, 14%, and 10.6%, respectively. Mechanical ventilation, elevated bilirubin level, and corticosteroid treatment for the indication of active graft-versus-host disease (GVHD) were independent predictors of death in the whole cohort. In the subgroup of patients requiring mechanical ventilation, associated organ failures, such as shock and liver dysfunction, were independent predictors of death. ICU admission during engraftment period was associated with acceptable outcome in mechanically ventilated patients, whereas patients with late complications of HSCT in the setting of active GVHD had a poor outcome. Extensive unlimited intensive care support is justified for allogeneic HSCT recipients with complications occurring during the engraftment period. Conversely, initiation or maintenance of mechanical ventilation is questionable in the setting of active GVHD.

Ventilation Inception and Washout, Scaling, and Effects on Hydrodynamic Performance of a Surface Piercing Strut

NASA Astrophysics Data System (ADS)

Harwood, Casey; Young, Yin Lu; Ceccio, Steven

2014-11-01

High-lift devices that operate at or near a fluid free surface (such as surface-piercing or shallowly-submerged propellers and hydrofoils) are prone to a multiphase flow phenomenon called ventilation, wherein non-condensable gas is entrained in the low-pressure flow, forming a cavity around the body and dramatically altering the global hydrodynamic forces. Experiments are being conducted at the University of Michigan's towing tank using a canonical surface-piercing strut to investigate atmospheric ventilation. The goals of the work are (i) to gain an understanding of the dominant physics in fully wetted, partially ventilated, and fully ventilated flow regimes, (ii) to quantify the effects of governing dimensionless parameters on the transition between flow regimes, and (iii) to develop scaling relations for the transition between flow regimes. Using theoretical arguments and flow visualization techniques, new criteria are developed for classifying flow regimes and transition mechanisms. Unsteady transition mechanisms are described and mapped as functions of the governing non-dimensional parameters. A theoretical scaling relationship is developed for ventilation washout, which is shown to adequately capture the experimentally-observed washout boundary. This material is based upon work supported by the National Science Foundation Graduate Student Research Fellowship under Grant No. DGE 1256260. Support also comes from the Naval Engineering Education Center (Award No. N65540-10-C-003).

Outcome of long-term mechanical ventilation support in children.

PubMed

Hsia, Shao-Hsuan; Lin, Jainn-Jim; Huang, I-Anne; Wu, Chang-Teng

2012-10-01

Improved technology and care in recent years have significantly improved the prognosis and quality of life for patients on long-term mechanical ventilation. This study examined the status of children on long-term mechanical ventilation (MV) support in Taiwan. The medical records of patients between January 1998 and December 2006 were retrospectively reviewed, and the clinical factors were systematically reviewed. One hundred and thirty-nine (139) patients aged 3 months to 18 years, with 53 (38.1%) girls and 86 (61.9%) boys, were enrolled. The common underlying disorders included neurologic/neuromuscular diseases (n=100, 71.9%) and airway/lung dysfunction (n=19, 13.7%). After instituting MV, the children returned to the medical center mainly for infection (n=157, 47.7%) and elective surgery or procedures (n=46, 13.9%). After long-term follow-up, 37 (26.6%) died, 81 (58.3%) were transferred to respiratory care wards in local hospitals, and 21 (15.1%) received home care support. There are now more children on long-term MV support in Taiwan and most are in respiratory care wards in local hospitals. The shift in underlying diagnoses from pulmonary disease to neurogenic respiratory insufficiency affects hospitalization. The main cause of respiratory insufficiency is neurologic insult. Copyright © 2012. Published by Elsevier B.V.

Cost-Effectiveness Analysis of Nasal Continuous Positive Airway Pressure Versus Nasal High Flow Therapy as Primary Support for Infants Born Preterm.

PubMed

Huang, Li; Roberts, Calum T; Manley, Brett J; Owen, Louise S; Davis, Peter G; Dalziel, Kim M

2018-05-01

To compare the cost-effectiveness of 2 common "noninvasive" modes of respiratory support for infants born preterm. An economic evaluation was conducted as a component of a multicenter, randomized control trial from 2013 to 2015 enrolling infants born preterm at ≥28 weeks of gestation with respiratory distress, <24 hours old, who had not previously received endotracheal intubation and mechanical ventilation or surfactant. The economic evaluation was conducted from a healthcare sector perspective and the time horizon was from birth until death or first discharge. The cost-effectiveness of continuous positive airway pressure (CPAP) vs high-flow with "rescue" CPAP backup and high-flow without rescue CPAP backup (as sole primary support) were analyzed by using the hospital cost of inpatient stay in a tertiary center and the rates of endotracheal intubation and mechanical ventilation during admission. Hospital inpatient cost records for 435 infants enrolled in all Australian centers were obtained. With "rescue" CPAP backup, an incremental cost-effectiveness ratio was estimated of A$179 000 (US$123 000) per ventilation avoided if CPAP was used compared with high flow. Without rescue CPAP backup, cost per ventilation avoided was A$7000 (US$4800) if CPAP was used compared with high flow. As sole primary support, CPAP is highly likely to be cost-effective compared with high flow. Neonatal units choosing to use only one device should apply CPAP as primary respiratory support. Compared with high-flow with rescue CPAP backup, CPAP is unlikely to be cost-effective if willingness to pay per ventilation avoided is less than A$179 000 (US$123 000). Copyright © 2018 Elsevier Inc. All rights reserved.

Acetazolamide: a second wind for a respiratory stimulant in the intensive care unit?

PubMed Central

2012-01-01

Patients with chronic obstructive pulmonary disease (COPD) are affected by episodes of respiratory exacerbations, some of which can be severe and may necessitate respiratory support. Prolonged invasive mechanical ventilation is associated with increased mortality rates. Persistent failure to discontinue invasive mechanical ventilation is a major issue in patients with COPD. Pure or mixed metabolic alkalosis is a common finding in the intensive care unit (ICU) and is associated with a worse outcome. In patients with COPD, the condition is called post-hypercapnic alkalosis and is a complication of mechanical ventilation. Reversal of metabolic alkalosis may facilitate weaning from mechanical ventilation of patients with COPD. Acetazolamide, a non-specific carbonic anhydrase inhibitor, is one of the drugs employed in the ICU to reverse metabolic alkalosis. The drug is relatively safe, undesirable effects being rare. The compartmentalization of the different isoforms of the carbonic anhydrase enzyme may, in part, explain the lack of evidence of the efficacy of acetazolamide as a respiratory stimulant. Recent findings suggest that the usually employed doses of acetazolamide in the ICU may be insufficient to significantly improve respiratory parameters in mechanically ventilated patients with COPD. Randomized controlled trials using adequate doses of acetazolamide are required to address this issue. PMID:22866939

Systolic blood pressure is superior to other haemodynamic predictors of outcome in community acquired pneumonia.

PubMed

Chalmers, J D; Singanayagam, A; Hill, A T

2008-08-01

Admission blood pressure (BP) assessment is a central component of severity assessment for community acquired pneumonia. The aim of this study was to establish which readily available haemodynamic measure on admission is most useful for predicting severity in patients admitted with community acquired pneumonia. A prospective observational study of patients admitted with community acquired pneumonia was conducted in Edinburgh, UK. The measurements compared were systolic and diastolic BP, mean arterial pressure and pulse pressure. The outcomes of interest were 30 day mortality and the requirement for mechanical ventilation and/or inotropic support. Admission systolic BP < 90 mm Hg, diastolic BP < or = 60 mm Hg, mean arterial pressure < 70 mm Hg and pulse pressure < or = 40 mm Hg were all associated with increased 30 day mortality and the need for mechanical ventilation and/or inotropic support on multivariate logistic regression. The AUC values for each predictor of 30 day mortality were as follows: systolic BP < 90 mm Hg 0.70; diastolic BP < or = 60 mm Hg 0.59; mean arterial pressure < 70 mm Hg 0.64; and pulse pressure < or = 40 mm Hg 0.60. The AUC values for each predictor of need for mechanical ventilation and/or inotropic support were as follows: systolic BP < 90 mm Hg 0.70; diastolic BP < or = 60 mm Hg 0.68; mean arterial pressure < 70 mm Hg 0.69; and pulse pressure < or = 40 mm Hg 0.59. A simplified CRB65 score containing systolic blood pressure < 90 mm Hg alone performed equally well to standard CRB65 score (AUC 0.76 vs 0.74) and to the standard CURB65 score (0.76 vs 0.76) for the prediction of 30 day mortality. The simplified CRB65 score was equivalent for prediction of mechanical ventilation and/or inotropic support to standard CRB65 (0.77 vs 0.77) and to CURB65 (0.77 vs 0.78). Systolic BP is superior to other haemodynamic predictors of 30 day mortality and need for mechanical ventilation and/or inotropic support in community acquired pneumonia. The CURB65 score can be simplified to a modified CRB65 score by omission of the diastolic BP criterion without compromising its accuracy.

Core Outcomes in Ventilation Trials (COVenT): protocol for a core outcome set using a Delphi survey with a nested randomised trial and observational cohort study.

PubMed

Blackwood, Bronagh; Ringrow, Suzanne; Clarke, Mike; Marshall, John; Rose, Louise; Williamson, Paula; McAuley, Danny

2015-08-20

Among clinical trials of interventions that aim to modify time spent on mechanical ventilation for critically ill patients there is considerable inconsistency in chosen outcomes and how they are measured. The Core Outcomes in Ventilation Trials (COVenT) study aims to develop a set of core outcomes for use in future ventilation trials in mechanically ventilated adults and children. We will use a mixed methods approach that incorporates a randomised trial nested within a Delphi study and a consensus meeting. Additionally, we will conduct an observational cohort study to evaluate uptake of the core outcome set in published studies at 5 and 10 years following core outcome set publication. The three-round online Delphi study will use a list of outcomes that have been reported previously in a review of ventilation trials. The Delphi panel will include a range of stakeholder groups including patient support groups. The panel will be randomised to one of three feedback methods to assess the impact of the feedback mechanism on subsequent ranking of outcomes. A final consensus meeting will be held with stakeholder representatives to review outcomes. The COVenT study aims to develop a core outcome set for ventilation trials in critical care, explore the best Delphi feedback mechanism for achieving consensus and determine if participation increases use of the core outcome set in the long term.

Technical aspects and clinical implications of high frequency jet ventilation with a solenoid valve.

PubMed

Carlon, G C; Miodownik, S; Ray, C; Kahn, R C

1981-01-01

High frequency jet ventilation (HFJV) is an incompletely studied technique of mechanical respiratory support. The authors have built a ventilator based on a solenoid valve, that allows independent selection of respiratory rate and inspiratory/expiratory ratio. The ventilator can be synchronized to the heart rate. Humidification is provided by warm saline dripped in front of the injector nozzle, so that the jet stream itself acts as a nebulizer. Tube diameter, length, and deformability are fundamental determinants of inspiratory flow rate and wave form. Cannula kinking and inadequate humidification were the most significant sources of complications.

Mechanical ventilation in disaster situations: a new paradigm using the AGILITIES Score System.

PubMed

Wilkens, Eric P; Klein, Gary M

2010-01-01

The failure of life-critical systems such as mechanical ventilators in the wake of a pandemic or a disaster may result in death, and therefore, state and federal government agencies must have precautions in place to ensure availability, reliability, and predictability through comprehensive preparedness and response plans. All 50 state emergency preparedness response plans were extensively examined for the attention given to the critically injured and ill patient population during a pandemic or mass casualty event. Public health authorities of each state were contacted as well. Nine of 51 state plans (17.6 percent) included a plan or committee for mechanical ventilation triage and management in a pandemic influenza event. All 51 state plans relied on the Centers for Disease Control and Prevention Flu Surge 2.0 spreadsheet to provide estimates for their influenza planning. In the absence of more specific guidance, the authors have developed and provided guidelines recommended for ventilator triage and the implementation of the AGILITIES Score in the event of a pandemic, mass casualty event, or other catastrophic disaster. The authors present and describe the AGILITIES Score Ventilator Triage System and provide related guidelines to be adopted uniformly by government agencies and hospitals. This scoring system and the set ofguidelines are to be used iA disaster settings, such as Hurricane Katrina, and are based on three key factors: relative health, duration of time on mechanical ventilation, and patients' use of resources during a disaster. For any event requiring large numbers of ventilators for patients, the United States is woefully unprepared. The deficiencies in this aspect of preparedness include (1) lack of accountability for physical ventilators, (2) lack of understanding with which healthcare professionals can safely operate these ventilators, (3) lack of understanding from where additional ventilator resources exist, and (4) a triage strategy to provide ventilator support to those patients with the greatest chances of survival.

Variability of Tidal Volume in Patient-Triggered Mechanical Ventilation in ARDS.

PubMed

Perinel-Ragey, Sophie; Baboi, Loredana; Guérin, Claude

2017-11-01

Limiting tidal volume (V T ) in patients with ARDS may not be achieved once patient-triggered breaths occur. Furthermore, ICU ventilators offer numerous patient-triggered modes that work differently across brands. We systematically investigated, using a bench model, the effect of patient-triggered modes on the size and variability of V T at different breathing frequencies (f), patient effort, and ARDS severity. We used a V500 Infinity ICU ventilator connected to an ASL 5000 lung model whose compliance was mimicking mild, moderate, and severe ARDS. Thirteen patient-triggered modes were tested, falling into 3 categories, namely volume control ventilation with mandatory minute ventilation; pressure control ventilation, including airway pressure release ventilation (APRV); and pressure support ventilation. Two levels of f and effort were tested for each ARDS severity in each mode. Median (first-third quartiles) V T was compared across modes using non-parametric tests. The probability of V T > 6 mL/kg ideal body weight was assessed by binomial regression and expressed as the odds ratio (OR) with 95% CI. V T variability was measured from the coefficient of variation. V T distribution over all f, effort, and ARDS categories significantly differed across modes ( P < .001, Kruskal-Wallis test). V T was significantly greater with pressure support (OR 420 mL, 95% CI 332-527 mL) than with any other mode except for variable pressure support level. Risk for V T to be > 6 mL/kg was significantly increased with spontaneous breaths patient-triggered by pressure support (OR 19.36, 95% CI 12.37-30.65) and significantly reduced in APRV (OR 0.44, 95% CI 0.26-0.72) and pressure support with guaranteed volume mode. The risk increased with increasing effort and decreasing f. Coefficient of variation of V T was greater for low f and volume control-mandatory minute ventilation and pressure control modes. APRV had the greatest within-mode variability. Risk of V T > 6 mL/kg was significantly reduced in APRV and pressure support with guaranteed volume mode. APRV had the highest variability. Pressure support with guaranteed volume could be tested in patients with ARDS. Copyright © 2017 by Daedalus Enterprises.

Home mechanical ventilation: A Canadian Thoracic Society clinical practice guideline

PubMed Central

McKim, Douglas A; Road, Jeremy; Avendano, Monica; Abdool, Steve; Côté, Fabien; Duguid, Nigel; Fraser, Janet; Maltais, François; Morrison, Debra L; O’Connell, Colleen; Petrof, Basil J; Rimmer, Karen; Skomro, Robert

2011-01-01

Increasing numbers of patients are surviving episodes of prolonged mechanical ventilation or benefitting from the recent availability of user-friendly noninvasive ventilators. Although many publications pertaining to specific aspects of home mechanical ventilation (HMV) exist, very few comprehensive guidelines that bring together all of the current literature on patients at risk for or using mechanical ventilatory support are available. The Canadian Thoracic Society HMV Guideline Committee has reviewed the available English literature on topics related to HMV in adults, and completed a detailed guideline that will help standardize and improve the assessment and management of individuals requiring noninvasive or invasive HMV. The guideline provides a disease-specific review of illnesses including amyotrophic lateral sclerosis, spinal cord injury, muscular dystrophies, myotonic dystrophy, kyphoscoliosis, post-polio syndrome, central hypoventilation syndrome, obesity hypoventilation syndrome, and chronic obstructive pulmonary disease as well as important common themes such as airway clearance and the process of transition to home. The guidelines have been extensively reviewed by international experts, allied health professionals and target audiences. They will be updated on a regular basis to incorporate any new information. PMID:22059178

Role of analgesics, sedatives, neuromuscular blockers, and delirium.

PubMed

Hall, Jesse B; Schweickert, William; Kress, John P

2009-10-01

A major focus on critical care medicine concerns the institution of life-support therapies, such as mechanical ventilation, during periods of organ failure to permit a window of opportunity to diagnose and treat underlying disorders so that patients may be returned to their prior functional status upon recovery. With the growing success of these intensive care unit-based therapies and longer-term follow-up of patients, severe weakness involving the peripheral nervous system and muscles has been identified in many recovering patients, often confounding the time course or magnitude of recovery. Mechanical ventilation is often accompanied by pharmacologic treatments including analgesics, sedatives, and neuromuscular blockers. These drugs and the encephalopathies accompanying some forms of critical illness result in a high prevalence of delirium in mechanically ventilated patients. These drug effects likely contribute to an impaired ability to assess the magnitude of intensive care unit-acquired weakness, to additional time spent immobilized and mechanically ventilated, and to additional weakness from the patient's relative immobility and bedridden state. This review surveys recent literature documenting these relationships and identifying approaches to minimize pharmacologic contributions to intensive care unit-acquired weakness.

Randomized clinical trial of extended use of a hydrophobic condenser humidifier: 1 vs. 7 days.

PubMed

Thomachot, Laurent; Leone, Marc; Razzouk, Karim; Antonini, François; Vialet, Renaud; Martin, Claude

2002-01-01

To determine whether extended use (7 days) would affect the efficiency on heat and water preservation of a hydrophobic condenser humidifier as well as the rate of ventilation-acquired pneumonia, compared with 1 day of use. Prospective, controlled, randomized, not blinded, clinical study. Twelve-bed intensive care unit of a university hospital. One hundred and fifty-five consecutive patients undergoing mechanical ventilation for > or = 48 hrs. After randomization, patients were allocated to one of the two following groups: a) heat and moisture exchangers (HMEs) changed every 24 hrs; b) HMEs changed only once a week. Devices in both groups could be changed at the discretion of the staff when signs of occlusion or increased resistance were identified. Efficient airway humidification and heating were assessed by clinical variables (numbers of tracheal suctionings and instillations required, peak and mean airway pressures). The frequency rates of bronchial colonization and ventilation-acquired pneumonia were evaluated by using clinical and microbiological criteria. Endotracheal tube occlusion, ventilatory support variables, duration of mechanical ventilation, length of intensive care, acquired multiorgan dysfunction, and mortality rates also were recorded. The two groups were similar at the time of randomization. Endotracheal tube occlusion never occurred. In the targeted population (patients ventilated for > or = 7 days), the frequency rate of ventilation-acquired pneumonia was 24% in the HME 1-day group and 17% in the HME 7-day group (p > .05, not significant). Ventilation-acquired pneumonia rates per 1000 ventilatory support days were 16.4/1000 in the HME 1-day group and 12.4/1000 in the HME 7-day group (p > .05, not significant). No statistically significant differences were found between the two groups for duration of mechanical ventilation, intensive care unit length of stay, acquired organ system derangements, and mortality rate. There was indirect evidence of very little, if any, change in HME resistance. Changing the studied hydrophobic HME after 7 days did not affect efficiency, increase resistance, or altered bacterial colonization. The frequency rate of ventilation-acquired pneumonia was also unchanged. Use of HMEs for > 24 hrs and up to 7 days is safe.

Lung protective mechanical ventilation strategies in cardiothoracic critical care: a retrospective study.

PubMed

Zochios, Vasileios; Hague, Matthew; Giraud, Kimberly; Jones, Nicola

2016-01-01

A body of evidence supports the use of low tidal volumes in ventilated patients without lung pathology to slow progress to acute respiratory distress syndrome (ARDS) due to ventilator associated lung injury. We undertook a retrospective chart review and tested the hypothesis that tidal volume is a predictor of mortality in cardiothoracic (medical and surgical) critical care patients receiving invasive mechanical ventilation. Independent predictors of mortality in our study included: type of surgery, albumin, H + , bilirubin, and fluid balance. In particular, it is important to note that cardiac, thoracic, and transplant surgical patients were associated with lower mortality. However, our study did not sample equally from The Berlin Definition of ARDS severity categories (mild, moderate, and severe hypoxemia). Although our study was not adequately powered to detect a difference in mortality between these groups, it will inform the development of a large prospective cohort study exploring the role of low tidal volume ventilation in cardiothoracic critically ill patients.

Nocturnal mechanical ventilation for chronic hypoventilation in patients with neuromuscular and chest wall disorders.

PubMed

Annane, Djillali; Orlikowski, David; Chevret, Sylvie

2014-12-13

Chronic alveolar hypoventilation is a common complication of many neuromuscular and chest wall disorders. Long-term nocturnal mechanical ventilation is commonly used to treat it. This is a 2014 update of a review first published in 2000 and previously updated in 2007. To examine the effects on mortality of nocturnal mechanical ventilation in people with neuromuscular or chest wall disorders. Subsidiary endpoints were to examine the effects of respiratory assistance on improvement of chronic hypoventilation, sleep quality, hospital admissions and quality of life. We searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE and EMBASE on 10 June 2014. We contacted authors of identified trials and other experts in the field. We searched for quasi-randomised or randomised controlled trials of participants of all ages with neuromuscular or chest wall disorder-related stable chronic hypoventilation of all degrees of severity, receiving any type and any mode of long-term nocturnal mechanical ventilation. The primary outcome measure was one-year mortality and secondary outcomes were unplanned hospital admission, short-term and long-term reversal of hypoventilation-related clinical symptoms and daytime hypercapnia, improvement of lung function and sleep breathing disorders. We used standard Cochrane methodology to select studies, extract data and assess the risk of bias in included studies. The 10 eligible trials included a total of 173 participants. Roughly half of the trials were at low risk of selection, attrition or reporting bias, and almost all were at high risk of performance and detection bias. Four trials reported mortality data in the long term. The pooled risk ratio (RR) of dying was 0.62 (95% confidence interval (CI) 0.42 to 0.91, P value = 0.01) in favour of nocturnal mechanical ventilation compared to spontaneous breathing. There was considerable and significant heterogeneity between the trials, possibly related to differences between the study populations. Information on unplanned hospitalisation was available from two studies. The corresponding pooled RR was 0.25 (95% CI 0.08 to 0.82, P value = 0.02) in favour of nocturnal mechanical ventilation. For most of the outcome measures there was no significant long-term difference between nocturnal mechanical ventilation and no ventilation. Most of the secondary outcomes were not assessed in the eligible trials. Three out of the 10 trials, accounting for 39 participants, two with a cross-over design and one with two parallel groups, compared volume- and pressure-cycled non-invasive mechanical ventilation in the short term. From the only trial (16 participants) on parallel groups, there was no difference in mortality (one death in each arm) between volume- and pressure-cycled mechanical ventilation. Data from the two cross-over trials suggested that compared with pressure-cycled ventilation, volume-cycled ventilation was associated with less sleep time spent with an arterial oxygen saturation below 90% (mean difference (MD) 6.83 minutes, 95% CI 4.68 to 8.98, P value = 0.00001) and a lower apnoea-hypopnoea (per sleep hour) index (MD -0.65, 95% CI -0.84 to -0.46, P value = 0.00001). We found no study that compared invasive and non-invasive mechanical ventilation or intermittent positive pressure versus negative pressure ventilation. Current evidence about the therapeutic benefit of mechanical ventilation is of very low quality, but is consistent, suggesting alleviation of the symptoms of chronic hypoventilation in the short term. In four small studies, survival was prolonged and unplanned hospitalisation was reduced, mainly in participants with motor neuron diseases. With the exception of motor neuron disease and Duchenne muscular dystrophy, for which the natural history supports the survival benefit of mechanical ventilation against no ventilation, further larger randomised trials should assess the long-term benefit of different types and modes of nocturnal mechanical ventilation on quality of life, morbidity and mortality, and its cost-benefit ratio in neuromuscular and chest wall diseases.

Utility and safety of draining pleural effusions in mechanically ventilated patients: a systematic review and meta-analysis

PubMed Central

2011-01-01

Introduction Pleural effusions are frequently drained in mechanically ventilated patients but the benefits and risks of this procedure are not well established. Methods We performed a literature search of multiple databases (MEDLINE, EMBASE, HEALTHSTAR, CINAHL) up to April 2010 to identify studies reporting clinical or physiological outcomes of mechanically ventilated critically ill patients who underwent drainage of pleural effusions. Studies were adjudicated for inclusion independently and in duplicate. Data on duration of ventilation and other clinical outcomes, oxygenation and lung mechanics, and adverse events were abstracted in duplicate independently. Results Nineteen observational studies (N = 1,124) met selection criteria. The mean PaO2:FiO2 ratio improved by 18% (95% confidence interval (CI) 5% to 33%, I2 = 53.7%, five studies including 118 patients) after effusion drainage. Reported complication rates were low for pneumothorax (20 events in 14 studies including 965 patients; pooled mean 3.4%, 95% CI 1.7 to 6.5%, I2 = 52.5%) and hemothorax (4 events in 10 studies including 721 patients; pooled mean 1.6%, 95% CI 0.8 to 3.3%, I2 = 0%). The use of ultrasound guidance (either real-time or for site marking) was not associated with a statistically significant reduction in the risk of pneumothorax (OR = 0.32; 95% CI 0.08 to 1.19). Studies did not report duration of ventilation, length of stay in the intensive care unit or hospital, or mortality. Conclusions Drainage of pleural effusions in mechanically ventilated patients appears to improve oxygenation and is safe. We found no data to either support or refute claims of beneficial effects on clinically important outcomes such as duration of ventilation or length of stay. PMID:21288334

The Effect of Listening to Holy Quran Recitation on Weaning Patients Receiving Mechanical Ventilation in the Intensive Care Unit: A Pilot Study.

PubMed

Yadak, Mohammad; Ansari, Khalid Aziz; Qutub, Hatem; Al-Otaibi, Hajed; Al-Omar, Omar; Al-Onizi, Nawal; Farooqi, Faraz Ahmed

2017-09-30

Mechanical ventilation (MV) causes high level of stress in hospitalized patients. Weaning is the gradual process of decreasing ventilator support that in turn lead to termination of MV and increased respiratory effort, which may exacerbate symptoms and prolong MV. This study aimed to investigate the effect of listening to Holy Quran recitation (HQR) as a non-pharmacological intervention in patients during weaning from mechanical ventilation. This is a randomized controlled trial in which 55 patients admitted in the intensive care unit (ICU) and on mechanical ventilation were recruited. Patients were divided into experimental (case) and control group. In the experimental group, patients received 30 min of HQR, whereas in the control group, patients had 30 min of rest in bed before the start of the weaning. The physiological and/or clinical parameters of weaning were recorded. These parameters include rapid shallow breathing index, respiratory rate, heart rate, oxygen saturation, exhaled carbon dioxide, and blood pressure. The baseline demographic data for groups were presented in tables. The mean age was 54 ± 0.5 years for the experimental and 56.4 ± 18.5 years for the control groups. The physiological and clinical parameters were compared between case and control and found no significant difference. The preliminary findings of this pilot study suggest that there is no negative effect of HQR on weaning patients from mechanical ventilation in the ICU. The results also outline and explorthe possible utility of HQR further in ICU patients as an intervention in weaning patients off from ventilator in the ICU. Although there remains much to be done, our work generates important findings in the field of critical care management.

Replicating human expertise of mechanical ventilation waveform analysis in detecting patient-ventilator cycling asynchrony using machine learning.

PubMed

Gholami, Behnood; Phan, Timothy S; Haddad, Wassim M; Cason, Andrew; Mullis, Jerry; Price, Levi; Bailey, James M

2018-06-01

- Acute respiratory failure is one of the most common problems encountered in intensive care units (ICU) and mechanical ventilation is the mainstay of supportive therapy for such patients. A mismatch between ventilator delivery and patient demand is referred to as patient-ventilator asynchrony (PVA). An important hurdle in addressing PVA is the lack of a reliable framework for continuously and automatically monitoring the patient and detecting various types of PVA. - The problem of replicating human expertise of waveform analysis for detecting cycling asynchrony (i.e., delayed termination, premature termination, or none) was investigated in a pilot study involving 11 patients in the ICU under invasive mechanical ventilation. A machine learning framework is used to detect cycling asynchrony based on waveform analysis. - A panel of five experts with experience in PVA evaluated a total of 1377 breath cycles from 11 mechanically ventilated critical care patients. The majority vote was used to label each breath cycle according to cycling asynchrony type. The proposed framework accurately detected the presence or absence of cycling asynchrony with sensitivity (specificity) of 89% (99%), 94% (98%), and 97% (93%) for delayed termination, premature termination, and no cycling asynchrony, respectively. The system showed strong agreement with human experts as reflected by the kappa coefficients of 0.90, 0.91, and 0.90 for delayed termination, premature termination, and no cycling asynchrony, respectively. - The pilot study establishes the feasibility of using a machine learning framework to provide waveform analysis equivalent to an expert human. Copyright © 2018 Elsevier Ltd. All rights reserved.

Case-Mix, Care Processes, and Outcomes in Medically-Ill Patients Receiving Mechanical Ventilation in a Low-Resource Setting from Southern India: A Prospective Clinical Case Series.

PubMed

Karthikeyan, Balasubramanian; Kadhiravan, Tamilarasu; Deepanjali, Surendran; Swaminathan, Rathinam Palamalai

2015-01-01

Mechanical ventilation is a resource intensive organ support treatment, and historical studies from low-resource settings had reported a high mortality. We aimed to study the outcomes in patients receiving mechanical ventilation in a contemporary low-resource setting. We prospectively studied the characteristics and outcomes (disease-related, mechanical ventilation-related, and process of care-related) in 237 adults mechanically ventilated for a medical illness at a teaching hospital in southern India during February 2011 to August 2012. Vital status of patients discharged from hospital was ascertained on Day 90 or later. Mean age of the patients was 40 ± 17 years; 140 (51%) were men. Poisoning and envenomation accounted for 98 (41%) of 237 admissions. In total, 87 (37%) patients died in-hospital; 16 (7%) died after discharge; 115 (49%) were alive at 90-day assessment; and 19 (8%) were lost to follow-up. Weaning was attempted in 171 (72%) patients; most patients (78 of 99 [79%]) failing the first attempt could be weaned off. Prolonged mechanical ventilation was required in 20 (8%) patients. Adherence to head-end elevation and deep vein thrombosis prophylaxis were 164 (69%) and 147 (62%) respectively. Risk of nosocomial infections particularly ventilator-associated pneumonia was high (57.2 per 1,000 ventilator-days). Higher APACHE II score quartiles (adjusted HR [95% CI] quartile 2, 2.65 [1.19-5.89]; quartile 3, 2.98 [1.24-7.15]; quartile 4, 5.78 [2.45-13.60]), and new-onset organ failure (2.98 [1.94-4.56]) were independently associated with the risk of death. Patients with poisoning had higher risk of reintubation (43% vs. 20%; P = 0.001) and ventilator-associated pneumonia (75% vs. 53%; P = 0.001). But, their mortality was significantly lower compared to the rest (24% vs. 44%; P = 0.002). The case-mix considerably differs from other settings. Mortality in this low-resource setting is similar to high-resource settings. But, further improvements in care processes and prevention of nosocomial infections are required.

Abdominal Muscle Activity during Mechanical Ventilation Increases Lung Injury in Severe Acute Respiratory Distress Syndrome.

PubMed

Zhang, Xianming; Wu, Weiliang; Zhu, Yongcheng; Jiang, Ying; Du, Juan; Chen, Rongchang

2016-01-01

It has proved that muscle paralysis was more protective for injured lung in severe acute respiratory distress syndrome (ARDS), but the precise mechanism is not clear. The purpose of this study was to test the hypothesis that abdominal muscle activity during mechanically ventilation increases lung injury in severe ARDS. Eighteen male Beagles were studied under mechanical ventilation with anesthesia. Severe ARDS was induced by repetitive oleic acid infusion. After lung injury, Beagles were randomly assigned into spontaneous breathing group (BIPAPSB) and abdominal muscle paralysis group (BIPAPAP). All groups were ventilated with BIPAP model for 8h, and the high pressure titrated to reached a tidal volume of 6ml/kg, the low pressure was set at 10 cmH2O, with I:E ratio 1:1, and respiratory rate adjusted to a PaCO2 of 35-60 mmHg. Six Beagles without ventilator support comprised the control group. Respiratory variables, end-expiratory volume (EELV) and gas exchange were assessed during mechanical ventilation. The levels of Interleukin (IL)-6, IL-8 in lung tissue and plasma were measured by qRT-PCR and ELISA respectively. Lung injury scores were determined at end of the experiment. For the comparable ventilator setting, as compared with BIPAPSB group, the BIPAPAP group presented higher EELV (427±47 vs. 366±38 ml) and oxygenation index (293±36 vs. 226±31 mmHg), lower levels of IL-6(216.6±48.0 vs. 297.5±71.2 pg/ml) and IL-8(246.8±78.2 vs. 357.5±69.3 pg/ml) in plasma, and lower express levels of IL-6 mRNA (15.0±3.8 vs. 21.2±3.7) and IL-8 mRNA (18.9±6.8 vs. 29.5±7.9) in lung tissues. In addition, less lung histopathology injury were revealed in the BIPAPAP group (22.5±2.0 vs. 25.2±2.1). Abdominal muscle activity during mechanically ventilation is one of the injurious factors in severe ARDS, so abdominal muscle paralysis might be an effective strategy to minimize ventilator-induce lung injury.

Low tidal volume mechanical ventilation against no ventilation during cardiopulmonary bypass heart surgery (MECANO): study protocol for a randomized controlled trial.

PubMed

Nguyen, Lee S; Merzoug, Messaouda; Estagnasie, Philippe; Brusset, Alain; Law Koune, Jean-Dominique; Aubert, Stephane; Waldmann, Thierry; Grinda, Jean-Michel; Gibert, Hadrien; Squara, Pierre

2017-12-02

Postoperative pulmonary complications are a leading cause of morbidity and mortality after cardiac surgery. There are no recommendations on mechanical ventilation associated with cardiopulmonary bypass (CPB) during surgery and anesthesiologists perform either no ventilation (noV) at all during CPB or maintain low tidal volume (LTV) ventilation. Indirect evidence points towards better pulmonary outcomes when LTV is performed but no large-scale prospective trial has yet been published in cardiac surgery. The MECANO trial is a single-center, double-blind, randomized, controlled trial comparing two mechanical ventilation strategies, noV and LTV, during cardiac surgery with CPB. In total, 1500 patients are expected to be included, without any restrictions. They will be randomized between noV and LTV on a 1:1 ratio. The noV group will receive no ventilation during CPB. The LTV group will receive 5 breaths/minute with a tidal volume of 3 mL/kg and positive end-expiratory pressure of 5 cmH2O. The primary endpoint will be a composite of all-cause mortality, early respiratory failure defined as a ratio of partial pressure of oxygen/fraction of inspired oxygen <200 mmHg at 1 hour after arrival in the ICU, heavy oxygenation support (defined as a patient requiring either non-invasive ventilation, mechanical ventilation or high-flow oxygen) at 2 days after arrival in the ICU or ventilator-acquired pneumonia defined by the Center of Disease Control. Lung recruitment maneuvers will be performed in the noV and LTV groups at the end of surgery and at arrival in ICU with an insufflation at +30 cmH20 for 5 seconds. Secondary endpoints are those composing the primary endpoint with the addition of pneumothorax, CPB duration, quantity of postoperative bleeding, red blood cell transfusions, revision surgery requirements, length of stay in the ICU and in the hospital and total hospitalization costs. Patients will be followed until hospital discharge. The MECANO trial is the first of its kind to compare in a double-blind design, a no-ventilation to a low-tidal volume strategy for mechanical ventilation during cardiac surgery with CPB, with a primary composite outcome including death, respiratory failure and postoperative pneumonia. ClinicalTrials.gov, NCT03098524 . Registered on 27 February 2017.

Mechanical ventilation in acute respiratory distress syndrome: The open lung revisited.

PubMed

Amado-Rodríguez, L; Del Busto, C; García-Prieto, E; Albaiceta, G M

2017-12-01

Acute respiratory distress syndrome (ARDS) is still related to high mortality and morbidity rates. Most patients with ARDS will require ventilatory support. This treatment has a direct impact upon patient outcome and is associated to major side effects. In this regard, ventilator-associated lung injury (VALI) is the main concern when this technique is used. The ultimate mechanisms of VALI and its management are under constant evolution. The present review describes the classical mechanisms of VALI and how they have evolved with recent findings from physiopathological and clinical studies, with the aim of analyzing the clinical implications derived from them. Lastly, a series of knowledge-based recommendations are proposed that can be helpful for the ventilator assisted management of ARDS at the patient bedside. Copyright © 2017 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Risk of Unsuccessful Noninvasive Ventilation for Acute Respiratory Failure in Heterogeneous Neuromuscular Diseases: A Retrospective Study.

PubMed

Kataoka, Hiroshi; Nanaura, Hitoki; Kinugawa, Kaoru; Uchihara, Yuto; Ohara, Hiroya; Eura, Nobuyuki; Syobatake, Ryogo; Sawa, Nobuhiro; Takao, Kiriyama; Sugie, Kazuma; Ueno, Satoshi

2017-02-20

If invasive ventilation can be avoided by performing noninvasive mechanical ventilation (NIV) in patients with acute respiratory failure (ARF), the disease can be effectively managed. It is important to clarify the characteristics of patients with neuromuscular diseases in whom initial NIV is likely to be unsuccessful. We studied 27 patients in stable neuromuscular condition who initially received NIV to manage fatal ARF to identify differences in factors immediately before the onset of ARF among patients who receive continuous NIV support, patients who are switched from NIV to invasive ventilation, and patients in whom NIV is discontinued. Endpoints were evaluated 24 and 72 hours after the initiation of NIV. After 24 hours, all but 1 patient with amyotrophic lateral sclerosis (ALS) received continuous NIV support. 72 hours later, 5 patients were switched from NIV to invasive ventilation, and 5 patients continued to receive NIV support. 72 hours after the initiation of NIV, the proportion of patients with a diagnosis of ALS differed significantly among the three groups (P=0.039). NIV may be attempted to manage acute fatal respiratory failure associated with neuromuscular diseases, but clinicians should carefully manage the clinical course in patients with ALS.

Are there benefits or harm from pressure targeting during lung-protective ventilation?

PubMed

MacIntyre, Neil R; Sessler, Curtis N

2010-02-01

Mechanically, breath design is usually either flow/volume-targeted or pressure-targeted. Both approaches can effectively provide lung-protective ventilation, but they prioritize different ventilation parameters, so their responses to changing respiratory-system mechanics and patient effort are different. These different response behaviors have advantages and disadvantages that can be important in specific circumstances. Flow/volume targeting guarantees a set minute ventilation but sometimes may be difficult to synchronize with patient effort, and it will not limit inspiratory pressure. In contrast, pressure targeting, with its variable flow, may be easier to synchronize and will limit inspiratory pressure, but it provides no control over delivered volume. Skilled clinicians can maximize benefits and minimize problems with either flow/volume targeting or pressure targeting. Indeed, as is often the case in managing complex life-support devices, it is operator expertise rather than the device design features that most impacts patient outcomes.

Cerebral hypoxia

MedlinePlus

... support is most important. Treatment involves: Breathing assistance (mechanical ventilation) and oxygen Controlling the heart rate and rhythm Fluids, blood products, or medicines to raise blood pressure ...

Anaesthesia ventilators.

PubMed

Jain, Rajnish K; Swaminathan, Srinivasan

2013-09-01

Anaesthesia ventilators are an integral part of all modern anaesthesia workstations. Automatic ventilators in the operating rooms, which were very simple with few modes of ventilation when introduced, have become very sophisticated with many advanced ventilation modes. Several systems of classification of anaesthesia ventilators exist based upon various parameters. Modern anaesthesia ventilators have either a double circuit, bellow design or a single circuit piston configuration. In the bellows ventilators, ascending bellows design is safer than descending bellows. Piston ventilators have the advantage of delivering accurate tidal volume. They work with electricity as their driving force and do not require a driving gas. To enable improved patient safety, several modifications were done in circle system with the different types of anaesthesia ventilators. Fresh gas decoupling is a modification done in piston ventilators and in descending bellows ventilator to reduce th incidence of ventilator induced volutrauma. In addition to the conventional volume control mode, modern anaesthesia ventilators also provide newer modes of ventilation such as synchronised intermittent mandatory ventilation, pressure-control ventilation and pressure-support ventilation (PSV). PSV mode is particularly useful for patients maintained on spontaneous respiration with laryngeal mask airway. Along with the innumerable benefits provided by these machines, there are various inherent hazards associated with the use of the ventilators in the operating room. To use these workstations safely, it is important for every Anaesthesiologist to have a basic understanding of the mechanics of these ventilators and breathing circuits.

Critical care capacity in Canada: results of a national cross-sectional study.

PubMed

Fowler, Robert A; Abdelmalik, Philip; Wood, Gordon; Foster, Denise; Gibney, Noel; Bandrauk, Natalie; Turgeon, Alexis F; Lamontagne, François; Kumar, Anand; Zarychanski, Ryan; Green, Rob; Bagshaw, Sean M; Stelfox, Henry T; Foster, Ryan; Dodek, Peter; Shaw, Susan; Granton, John; Lawless, Bernard; Hill, Andrea; Rose, Louise; Adhikari, Neill K; Scales, Damon C; Cook, Deborah J; Marshall, John C; Martin, Claudio; Jouvet, Philippe

2015-04-01

Intensive Care Units (ICUs) provide life-supporting treatment; however, resources are limited, so demand may exceed supply in the event of pandemics, environmental disasters, or in the context of an aging population. We hypothesized that comprehensive national data on ICU resources would permit a better understanding of regional differences in system capacity. After the 2009-2010 Influenza A (H1N1) pandemic, the Canadian Critical Care Trials Group surveyed all acute care hospitals in Canada to assess ICU capacity. Using a structured survey tool administered to physicians, respiratory therapists and nurses, we determined the number of ICU beds, ventilators, and the ability to provide specialized support for respiratory failure. We identified 286 hospitals with 3170 ICU beds and 4982 mechanical ventilators for critically ill patients. Twenty-two hospitals had an ICU that routinely cared for children; 15 had dedicated pediatric ICUs. Per 100,000 population, there was substantial variability in provincial capacity, with a mean of 0.9 hospitals with ICUs (provincial range 0.4-2.8), 10 ICU beds capable of providing mechanical ventilation (provincial range 6-19), and 15 invasive mechanical ventilators (provincial range 10-24). There was only moderate correlation between ventilation capacity and population size (coefficient of determination (R(2)) = 0.771). ICU resources vary widely across Canadian provinces, and during times of increased demand, may result in geographic differences in the ability to care for critically ill patients. These results highlight the need to evolve inter-jurisdictional resource sharing during periods of substantial increase in demand, and provide background data for the development of appropriate critical care capacity benchmarks.

Older patients with late-stage COPD: Their illness experiences and involvement in decision-making regarding mechanical ventilation and noninvasive ventilation.

PubMed

Jerpseth, Heidi; Dahl, Vegard; Nortvedt, Per; Halvorsen, Kristin

2018-02-01

To explore the illness experiences of older patients with late-stage chronic obstructive pulmonary disease and to develop knowledge about how patients perceive their preferences to be taken into account in decision-making processes concerning mechanical ventilation and/or noninvasive ventilation. Decisions about whether older patients with late-stage chronic obstructive pulmonary disease will benefit from noninvasive ventilation treatment or whether the time has come for palliative treatment are complicated, both medically and ethically. Knowledge regarding patients' values and preferences concerning ventilation support is crucial yet often lacking. Qualitative design with a hermeneutic-phenomenological approach. The data consist of qualitative in-depth interviews with 12 patients from Norway diagnosed with late-stage chronic obstructive pulmonary disease. The data were analysed within the three interpretative contexts described by Kvale and Brinkmann. The participants described their lives as fragile and burdensome, frequently interrupted by unpredictable and frightening exacerbations. They lacked information about their diagnosis and prognosis and were often not included in decisions about noninvasive ventilation or mechanical ventilation. Findings indicate that these patients are highly vulnerable and have complex needs in terms of nursing care and medical treatment. Moreover, they need access to proactive advanced care planning and an opportunity to discuss their wishes for treatment and care. To provide competent care for these patients, healthcare personnel must be aware of how patients experience being seriously ill. Advanced care planning and shared decision-making should be initiated alongside the curative treatment. © 2017 John Wiley & Sons Ltd.

Lung-protective Ventilation in Patients with Brain Injury: A Multicenter Cross-sectional Study and Questionnaire Survey in China

PubMed Central

Luo, Xu-Ying; Hu, Ying-Hong; Cao, Xiang-Yuan; Kang, Yan; Liu, Li-Ping; Wang, Shou-Hong; Yu, Rong-Guo; Yu, Xiang-You; Zhang, Xia; Li, Bao-Shan; Ma, Zeng-Xiang; Weng, Yi-Bing; Zhang, Heng; Chen, De-Chang; Chen, Wei; Chen, Wen-Jin; Chen, Xiu-Mei; Du, Bin; Duan, Mei-Li; Hu, Jin; Huang, Yun-Feng; Jia, Gui-Jun; Li, Li-Hong; Liang, Yu-Min; Qin, Bing-Yu; Wang, Xian-Dong; Xiong, Jian; Yan, Li-Mei; Yang, Zheng-Ping; Dong, Chen-Ming; Wang, Dong-Xin; Zhan, Qing-Yuan; Fu, Shuang-Lin; Zhao, Lin; Huang, Qi-Bing; Xie, Ying-Guang; Huang, Xiao-Bo; Zhang, Guo-Bin; Xu, Wang-Bin; Xu, Yuan; Liu, Ya-Ling; Zhao, He-Ling; Sun, Rong-Qing; Sun, Ming; Cheng, Qing-Hong; Qu, Xin; Yang, Xiao-Feng; Xu, Ming; Shi, Zhong-Hua; Chen, Han; He, Xuan; Yang, Yan-Lin; Chen, Guang-Qiang; Sun, Xiu-Mei; Zhou, Jian-Xin

2016-01-01

Background: Over the years, the mechanical ventilation (MV) strategy has changed worldwide. The aim of the present study was to describe the ventilation practices, particularly lung-protective ventilation (LPV), among brain-injured patients in China. Methods: This study was a multicenter, 1-day, cross-sectional study in 47 Intensive Care Units (ICUs) across China. Mechanically ventilated patients (18 years and older) with brain injury in a participating ICU during the time of the study, including traumatic brain injury, stroke, postoperation with intracranial tumor, hypoxic-ischemic encephalopathy, intracranial infection, and idiopathic epilepsy, were enrolled. Demographic data, primary diagnoses, indications for MV, MV modes and settings, and prognoses on the 60th day were collected. Multivariable logistic analysis was used to assess factors that might affect the use of LPV. Results: A total of 104 patients were enrolled in the present study, 87 (83.7%) of whom were identified with severe brain injury based on a Glasgow Coma Scale ≤8 points. Synchronized intermittent mandatory ventilation (SIMV) was the most frequent ventilator mode, accounting for 46.2% of the entire cohort. The median tidal volume was set to 8.0 ml/kg (interquartile range [IQR], 7.0–8.9 ml/kg) of the predicted body weight; 50 (48.1%) patients received LPV. The median positive end-expiratory pressure (PEEP) was set to 5 cmH2O (IQR, 5–6 cmH2O). No PEEP values were higher than 10 cmH2O. Compared with partially mandatory ventilation, supportive and spontaneous ventilation practices were associated with LPV. There were no significant differences in mortality and MV duration between patients subjected to LPV and those were not. Conclusions: Among brain-injured patients in China, SIMV was the most frequent ventilation mode. Nearly one-half of the brain-injured patients received LPV. Patients under supportive and spontaneous ventilation were more likely to receive LPV. Trial Registration: ClinicalTrials.org NCT02517073 https://clinicaltrials.gov/ct2/show/NCT02517073. PMID:27411450

46 CFR 154.1200 - Mechanical ventilation system: General.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: General. 154.1200 Section... Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a... cargo handling equipment must have a fixed, exhaust-type mechanical ventilation system. (b) The...

[Neurally adjusted ventilatory assist (NAVA). A new mode of assisted mechanical ventilation].

PubMed

Moerer, O; Barwing, J; Quintel, M

2008-10-01

The aim of mechanical ventilation is to assure gas exchange while efficiently unloading the respiratory muscles and mechanical ventilation is an integral part of the care of patients with acute respiratory failure. Modern lung protective strategies of mechanical ventilation include low-tidal-volume ventilation and the continuation of spontaneous breathing which has been shown to be beneficial in reducing atelectasis and improving oxygenation. Poor patient-ventilator interaction is a major issue during conventional assisted ventilation. Neurally adjusted ventilator assist (NAVA) is a new mode of mechanical ventilation that uses the electrical activity of the diaphragm (EAdi) to control the ventilator. First experimental studies showed an improved patient-ventilator synchrony and an efficient unloading of the respiratory muscles. Future clinical studies will have to show that NAVA is of clinical advantage when compared to conventional modes of assisted mechanical ventilation. This review characterizes NAVA according to current publications on this topic.

Mechanical Ventilation–associated Lung Fibrosis in Acute Respiratory Distress Syndrome A Significant Contributor to Poor Outcome

PubMed Central

Cabrera-Benitez, Nuria E.; Laffey, John G.; Parotto, Matteo; Spieth, Peter M.; Villar, Jesús; Zhang, Haibo; Slutsky, Arthur S.

2016-01-01

One of the most challenging problems in critical care medicine is the management of patients with the acute respiratory distress syndrome. Increasing evidence from experimental and clinical studies suggests that mechanical ventilation, which is necessary for life support in patients with acute respiratory distress syndrome, can cause lung fibrosis, which may significantly contribute to morbidity and mortality. The role of mechanical stress as an inciting factor for lung fibrosis versus its role in lung homeostasis and the restoration of normal pulmonary parenchymal architecture is poorly understood. In this review, the authors explore recent advances in the field of pulmonary fibrosis in the context of acute respiratory distress syndrome, concentrating on its relevance to the practice of mechanical ventilation, as commonly applied by anesthetists and intensivists. The authors focus the discussion on the thesis that mechanical ventilation—or more specifically, that ventilator-induced lung injury—may be a major contributor to lung fibrosis. The authors critically appraise possible mechanisms underlying the mechanical stress–induced lung fibrosis and highlight potential therapeutic strategies to mitigate this fibrosis. PMID:24732023

The effect of closed system suction on airway pressures when using the Servo 300 ventilator.

PubMed

Frengley, R W; Closey, D N; Sleigh, J W; Torrance, J M

2001-12-01

To measure airway pressures during closed system suctioning with the ventilator set to three differing modes of ventilation. Closed system suctioning was conducted in 16 patients following cardiac surgery. Suctioning was performed using a 14 French catheter with a vacuum level of -500 cmH2O through an 8.0 mm internal diameter endotracheal tube. The lungs were mechanically ventilated with a Servo 300 ventilator set to one of three ventilation modes: volume-control, pressure-control or CPAP/pressure support. Airway pressures were measured via a 4 French electronic pressure transducer in both proximal and distal airways. Following insertion of the suction catheter, end-expiratory pressure increased significantly (p < 0.001) in both pressure-control and volume-control ventilation. This increase was greatest (p = 0.018) in volume-control mode (2.7 +/- 1.7 cmH2O). On performing a five second suction, airway pressure decreased in all modes, however the lowest airway pressure in volume-control mode (-4.9 +/- 4.0 cmH2O) was significantly (p = 0.001) less than the lowest airway pressure recorded in either pressure-control (0.8 +/- 1.9 cmH2O) or CPAP/pressure support (0.4 +/- 2.8 cmH2O) modes. In CPAP/pressure support mode, 13 of the 16 patients experienced a positive pressure 'breath' at the end of suctioning with airway pressures rising to 21 +/- 1.6 cmH2O. Closed system suctioning in volume control ventilation may result in elevations of end-expiratory pressure following catheter insertion and subatmospheric airway pressures during suctioning. Pressure control ventilation produces less elevation of end-expiratory pressure following catheter insertion and is less likely to be associated with subatmospheric airway pressures during suctioning. CPAP/pressure support has no effect on end-expiratory pressure following catheter insertion and subatmospheric airway pressures are largely avoided during suctioning.

Low-flow venovenous CO₂ removal in association with lung protective ventilation strategy in patients who develop severe progressive respiratory acidosis after lung transplantation.

PubMed

Ruberto, F; Bergantino, B; Testa, M C; D'Arena, C; Zullino, V; Congi, P; Paglialunga, S G; Diso, D; Venuta, F; Pugliese, F

2013-09-01

Primary graft dysfunction (PGD) might occur after lung transplantation. In some severe cases, conventional therapies like ventilatory support, administration of inhaled nitric oxide (iNO), and intravenous prostacyclins are not sufficient to provide an adequate gas exchange. The aim of our study was to evaluate the use of a lung protective ventilation strategy associated with a low-flow venovenous CO2 removal treatment to reduce ventilator-associated injury in patients that develop severe PGD after lung transplantation. From January 2009 to January 2011, 3 patients developed PGD within 24 hours after lung transplantation. In addition to conventional medical treatment, including hemodynamic support, iNO and prostaglandin E1 (PGE1), we initiated a ventilatory protective strategy associated with low-flow venovenous CO2 removal treatment (LFVVECCO2R). Hemodynamic and respiratory parameters were assessed at baseline as well as after 3, 12, 24, and 48 hours. No adverse events were registered. Despite decreased baseline elevated pulmonary positive pressures, application of a protective ventilation strategy with LFVVECCO2R reduced PaCO2 and pulmonary infiltrates as well as increased pH values and PaO2/FiO2 ratios. Every patient showed simultaneous improvement of clinical and hemodynamic conditions. They were weaned from mechanical ventilation and extubated after 24 hours after the use of the low-flow venovenous CO2 removal device. The use of LFVVECCO2R together with a protective lung ventilation strategy during the perioperative period of lung transplantation may be a valid clinical strategy for patients with PGD and severe respiratory acidosis occured despite adequate mechanical ventilation. Copyright © 2013 Elsevier Inc. All rights reserved.

46 CFR 154.1205 - Mechanical ventilation system: Standards.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: Standards. 154.1205... Equipment Cargo Area: Mechanical Ventilation System § 154.1205 Mechanical ventilation system: Standards. (a) Each exhaust type mechanical ventilation system required under § 154.1200 (a) must have ducts for...

Comparison of invasive and noninvasive positive pressure ventilation delivered by means of a helmet for weaning of patients from mechanical ventilation.

PubMed

Carron, Michele; Rossi, Sandra; Carollo, Cristiana; Ori, Carlo

2014-08-01

The effectiveness of noninvasive positive pressure ventilation delivered by helmet (H-NPPV) as a weaning approach in patients with acute respiratory failure is unclear. We randomly and evenly assigned 64 patients intubated for acute respiratory failure to conventional weaning with invasive mechanical ventilation (IMV) or H-NPPV. The primary end point was a reduction in IMV duration by 6 days between the 2 groups. Secondary end points were the occurrence of ventilator-associated pneumonia and major complications, duration of mechanical ventilation and weaning, intensive care unit and hospital length of stay, and survival. The mean duration of IMV was significantly reduced in the H-NPPV group compared with the IMV group (P<.0001), without significant difference in duration of weaning (P=.26) and total ventilatory support (P=.45). In the H-NPPV group, the incidence of major complications was less than the IMV group (P=.032). Compared with the H-NPPV group, the IMV group was associated with a greater incidence of VAP (P=.018) and an increased risk of nosocomial pneumonia (P=.049). The mortality rate was similar between the groups, with no significant difference in overall intensive care unit (P=.47) or hospital length of stay (P=.37). H-NPPV was well tolerated and effective in patients who were difficult to wean. Copyright © 2014 Elsevier Inc. All rights reserved.

Effect Of Pressure Support Versus Unassisted Breathing Through A Tracheostomy Collar On Weaning Duration In Patients Requiring Prolonged Mechanical Ventilation: A Randomized Trial

PubMed Central

Jubran, Amal; Grant, Brydon J.B.; Duffner, Lisa A.; Collins, Eileen G.; Lanuza, Dorothy M.; Hoffman, Leslie A.; Tobin, Martin J.

2013-01-01

Context Patients requiring prolonged mechanical ventilation (more than 21 days) are commonly weaned at long-term acute care hospitals (LTACHs). The most effective method of weaning such patients has not been investigated. Objective To compare weaning duration with pressure support versus unassisted breathing through a tracheostomy (trach collar) in patients transferred to a LTACH for weaning from prolonged ventilation. Design, Settings, and Participants Between 2000 and 2010, a randomized study was conducted in tracheotomized patients transferred to a single LTACH for weaning from prolonged ventilation. Of 500 patients who underwent a five-day screening procedure, 316 failed and were randomly assigned to wean with pressure support (n=155) or a trach collar (n=161). Six- and twelve-month survival was also determined. Main outcome measure Primary outcome was weaning duration. Secondary outcome was survival at six and twelve months after enrollment. Results Of 316 patients, four were withdrawn and not included in analysis. Of 152 patients in the pressure-support arm, 68 (44.7%) were weaned; 22 (14.5%) died. Of 160 patients in the trach-collar arm, 85 (53.1%) were weaned; 16 (10.0%) died. Median weaning time was shorter with trach collar than with pressure support: 15 [interquartile range, 8–25] versus 19 [12–31] days, p=0.004. The hazard ratio (HR) for successful weaning rate was higher with trach collar than with pressure support (HR, 1.43; 95% confidence interval [CI], 1.03–1.98, p<0.03) after adjusting for baseline clinical covariates. Trach collar achieved faster weaning than did pressure support among subjects who failed the screening procedure at 12–120 hours (HR, 3.33; 95% CI, 1.44–7.70, p<0.01), whereas weaning time was equivalent with the two methods in patients who failed the screening procedure within 0–12 hours. Mortality was equivalent in the pressure-support and trach-collar arms at six months (55.9% versus 51.3%; 4.7 difference, 95% CI −6.4 to 15.7%) and twelve months (66.4% versus 60.0%; 6.5 difference, 95% CI −4.2 to 17.1 %). Conclusion Among patients requiring prolonged mechanical ventilation and treated at a single long-term care facility, unassisted breathing through a tracheostomy, compared with pressure support, resulted in shorter median weaning time, although weaning mode had no effect on survival at 6 and 12 months. PMID:23340588

Effect of pressure support vs unassisted breathing through a tracheostomy collar on weaning duration in patients requiring prolonged mechanical ventilation: a randomized trial.

PubMed

Jubran, Amal; Grant, Brydon J B; Duffner, Lisa A; Collins, Eileen G; Lanuza, Dorothy M; Hoffman, Leslie A; Tobin, Martin J

2013-02-20

Patients requiring prolonged mechanical ventilation (>21 days) are commonly weaned at long-term acute care hospitals (LTACHs). The most effective method of weaning such patients has not been investigated. To compare weaning duration with pressure support vs unassisted breathing through a tracheostomy collar in patients transferred to an LTACH for weaning from prolonged ventilation. Between 2000 and 2010, a randomized study was conducted in tracheotomized patients transferred to a single LTACH for weaning from prolonged ventilation. Of 500 patients who underwent a 5-day screening procedure, 316 did not tolerate the procedure and were randomly assigned to receive weaning with pressure support (n = 155) or a tracheostomy collar (n = 161). Survival at 6- and 12-month time points was also determined. Primary outcome was weaning duration. Secondary outcome was survival at 6 and 12 months after enrollment. Of 316 patients, 4 were withdrawn and not included in analysis. Of 152 patients in the pressure-support group, 68 (44.7%) were weaned; 22 (14.5%) died. Of 160 patients in the tracheostomy collar group, 85 (53.1%) were weaned; 16 (10.0%) died. Median weaning time was shorter with tracheostomy collar use (15 days; interquartile range [IQR], 8-25) than with pressure support (19 days; IQR, 12-31), P = .004. The hazard ratio (HR) for successful weaning rate was higher with tracheostomy collar use than with pressure support (HR, 1.43; 95% CI, 1.03-1.98; P = .033) after adjusting for baseline clinical covariates. Use of the tracheostomy collar achieved faster weaning than did pressure support among patients who did not tolerate the screening procedure between 12 and 120 hours (HR, 3.33; 95% CI, 1.44-7.70; P = .005), whereas weaning time was equivalent with the 2 methods in patients who did not tolerate the screening procedure within 0 to 12 hours. Mortality was equivalent in the pressure-support and tracheostomy collar groups at 6 months (55.92% vs 51.25%; 4.67% difference, 95% CI, -6.4% to 15.7%) and at 12 months (66.45% vs 60.00%; 6.45% difference, 95% CI, -4.2% to 17.1%). Among patients requiring prolonged mechanical ventilation and treated at a single long-term care facility, unassisted breathing through a tracheostomy, compared with pressure support, resulted in shorter median weaning time, although weaning mode had no effect on survival at 6 and 12 months. clinicaltrials.gov Identifier: NCT01541462.

[Alveolar ventilation and recruitment under lung protective ventilation].

PubMed

Putensen, Christian; Muders, Thomas; Kreyer, Stefan; Wrigge, Hermann

2008-11-01

Goal of mechanical ventilation is to improve gas exchange and reduce work of breathing without contributing to further lung injury. Besides providing adequate EELV and thereby arterial oxygenation PEEP in addition to a reduction in tidal volume is required to prevent cyclic alveolar collapse and tidal recruitment and hence protective mechanical ventilation. Currently, there is no consensus if and if yes at which price alveolar recruitment with high airway pressures should be intended ("open up the lung"), or if it is more important to reduce the mechanical stress and strain to the lungs as much as possible ("keep the lung closed"). Potential of alveolar recruitment differs from patient to patient but also between lung regions. Potential for recruitment depends probably more on regional lung mechanics - especially on lung elastance - than on the underlying disease. Based on available data neither high PEEP nor other methods used for alveolar recruitment could demonstrate a survival benefit in patients with ARDS. These results may support an individualized titration of PEEP or other manoeuvres used for recruitment taking into consideration the regional effects. Bedside imaging techniques allowing titration of PEEP or other manoeuvres to prevent end-expiratory alveolar collapse (tidal recruitment) and inspiratory overinflation may be a promising development.

Closed loop ventilation mode in Intensive Care Unit: a randomized controlled clinical trial comparing the numbers of manual ventilator setting changes.

PubMed

Arnal, Jean-Michel; Garnero, Aude; Novotni, Dominik; Corno, Gaëlle; Donati, Stéphane-Yannis; Demory, Didier; Quintana, Gabrielle; Ducros, Laurent; Laubscher, Thomas; Durand-Gasselin, Jacques

2018-01-01

There is an equipoise regarding closed-loop ventilation modes and the ability to reduce workload for providers. On one hand some settings are managed by the ventilator but on another hand the automatic mode introduces new settings for the user. This randomized controlled trial compared the number of manual ventilator setting changes between a full closed loop ventilation and oxygenation mode (INTELLiVENT-ASV®) and conventional ventilation modes (volume assist control and pressure support) in Intensive Care Unit (ICU) patients. The secondary endpoints were to compare the number of arterial blood gas analysis, the sedation dose and the user acceptance. Sixty subjects with an expected duration of mechanical ventilation of at least 48 hours were randomized to be ventilated using INTELLiVENT-ASV® or conventional modes with a protocolized weaning. All manual ventilator setting changes were recorded continuously from inclusion to successful extubation or death. Arterial blood gases were performed upon decision of the clinician in charge. User acceptance score was assessed for nurses and physicians once daily using a Likert Scale. The number of manual ventilator setting changes per 24 h-period per subject was lower in INTELLiVENT-ASV® as compared to conventional ventilation group (5 [4-7] versus 10 [7-17]) manuals settings per subject per day [P<0.001]). The number of arterial blood gas analysis and the sedation doses were not significantly different between the groups. Nurses and physicians reported that INTELLiVENT-ASV® was significantly easier to use as compared to conventional ventilation (P<0.001 for nurses and P<0.01 for physicians). For mechanically ventilated ICU patients, INTELLiVENT-ASV® significantly reduces the number of manual ventilator setting changes with the same number of arterial blood gas analysis and sedation dose, and is easier to use for the caregivers as compared to conventional ventilation modes.

Mask leak increases and minute ventilation decreases when chest compressions are added to bag ventilation in a neonatal manikin model.

PubMed

Tracy, Mark B; Shah, Dharmesh; Hinder, Murray; Klimek, Jan; Marceau, James; Wright, Audrey

2014-05-01

To determine changes in respiratory mechanics when chest compressions are added to mask ventilation, as recommended by the International Liaison Committee on Resuscitation (ILCOR) guidelines for newborn infants. Using a Laerdal Advanced Life Support leak-free baby manikin and a 240-mL self-inflating bag, 58 neonatal staff members were randomly paired to provide mask ventilation, followed by mask ventilation with chest compressions with a 1:3 ratio, for two minutes each. A Florian respiratory function monitor was used to measure respiratory mechanics, including mask leak. The addition of chest compressions to mask ventilation led to a significant reduction in inflation rate, from 63.9 to 32.9 breaths per minute (p < 0.0001), mean airway pressure reduced from 7.6 to 4.9 cm H2 O (p < 0.001), minute ventilation reduced from 770 to 451 mL/kg/min (p < 0.0001), and there was a significant increase in paired mask leak of 6.8% (p < 0.0001). Adding chest compressions to mask ventilation, in accordance with the ILCOR guidelines, in a manikin model is associated with a significant reduction in delivered ventilation and increase in mask leak. If similar findings occur in human infants needing an escalation in resuscitation, there is a potential risk of either delay in recovery or inadequate response to resuscitation. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Perioperative lung protective ventilation in obese patients.

PubMed

Fernandez-Bustamante, Ana; Hashimoto, Soshi; Serpa Neto, Ary; Moine, Pierre; Vidal Melo, Marcos F; Repine, John E

2015-05-06

The perioperative use and relevance of protective ventilation in surgical patients is being increasingly recognized. Obesity poses particular challenges to adequate mechanical ventilation in addition to surgical constraints, primarily by restricted lung mechanics due to excessive adiposity, frequent respiratory comorbidities (i.e. sleep apnea, asthma), and concerns of postoperative respiratory depression and other pulmonary complications. The number of surgical patients with obesity is increasing, and facing these challenges is common in the operating rooms and critical care units worldwide. In this review we summarize the existing literature which supports the following recommendations for the perioperative ventilation in obese patients: (1) the use of protective ventilation with low tidal volumes (approximately 8 mL/kg, calculated based on predicted -not actual- body weight) to avoid volutrauma; (2) a focus on lung recruitment by utilizing PEEP (8-15 cmH2O) in addition to recruitment maneuvers during the intraoperative period, as well as incentivized deep breathing and noninvasive ventilation early in the postoperative period, to avoid atelectasis, hypoxemia and atelectrauma; and (3) a judicious oxygen use (ideally less than 0.8) to avoid hypoxemia but also possible reabsorption atelectasis. Obesity poses an additional challenge for achieving adequate protective ventilation during one-lung ventilation, but different lung isolation techniques have been adequately performed in obese patients by experienced providers. Postoperative efforts should be directed to avoid hypoventilation, atelectasis and hypoxemia. Further studies are needed to better define optimum protective ventilation strategies and analyze their impact on the perioperative outcomes of surgical patients with obesity.

Closed-loop mechanical ventilation for lung injury: a novel physiological-feedback mode following the principles of the open lung concept.

PubMed

Schwaiberger, David; Pickerodt, Philipp A; Pomprapa, Anake; Tjarks, Onno; Kork, Felix; Boemke, Willehad; Francis, Roland C E; Leonhardt, Steffen; Lachmann, Burkhard

2018-06-01

Adherence to low tidal volume (V T ) ventilation and selected positive end-expiratory pressures are low during mechanical ventilation for treatment of the acute respiratory distress syndrome. Using a pig model of severe lung injury, we tested the feasibility and physiological responses to a novel fully closed-loop mechanical ventilation algorithm based on the "open lung" concept. Lung injury was induced by surfactant washout in pigs (n = 8). Animals were ventilated following the principles of the "open lung approach" (OLA) using a fully closed-loop physiological feedback algorithm for mechanical ventilation. Standard gas exchange, respiratory- and hemodynamic parameters were measured. Electrical impedance tomography was used to quantify regional ventilation distribution during mechanical ventilation. Automatized mechanical ventilation provided strict adherence to low V T -ventilation for 6 h in severely lung injured pigs. Using the "open lung" approach, tidal volume delivery required low lung distending pressures, increased recruitment and ventilation of dorsal lung regions and improved arterial blood oxygenation. Physiological feedback closed-loop mechanical ventilation according to the principles of the open lung concept is feasible and provides low tidal volume ventilation without human intervention. Of importance, the "open lung approach"-ventilation improved gas exchange and reduced lung driving pressures by opening atelectasis and shifting of ventilation to dorsal lung regions.

Predictive Associations of Music, Anxiety, and Sedative Exposure on Mechanical Ventilation Weaning Trials

PubMed Central

Hetland, Breanna; Lindquist, Ruth; Weinert, Craig R.; Peden-McAlpine, Cynthia; Savik, Kay; Chlan, Linda

2017-01-01

Background Weaning from mechanical ventilation requires increased respiratory effort, which can heighten anxiety and later prolong the need for mechanical ventilation. Objectives To examine the predictive associations of music intervention, anxiety, sedative exposure, and patients’ characteristics on time to initiation and duration of weaning trials of patients receiving mechanical ventilation. Methods A descriptive, correlational design was used for a secondary analysis of data from a randomized trial. Music listening was defined as self-initiated, patient-directed music via headphones. Anxiety was measured daily with a visual analog scale. Sedative exposure was operationalized as a daily sedation intensity score and a sedative dose frequency. Analyses consisted of descriptive statistics, graphing, survival analysis, Cox proportional hazards regression, and linear regression. Results Of 307 patients, 52% were women and 86% were white. Mean age was 59.3 (SD, 14.4) years, mean Acute Physiology and Chronic Health Evaluation III score was 62.9 (SD, 21.6), mean duration of ventilatory support was 8 (range, 1–52) days, and mean stay in the intensive care unit was 18 (range, 2–71) days. Music listening, anxiety levels, and sedative exposure did not influence time to initial weaning trial or duration of trials. Clinical factors of illness severity, days of weaning trials, and tracheostomy placement influenced weaning patterns in this sample. Conclusions Prospective studies of music intervention and other psychophysiological factors during weaning from mechanical ventilation are needed to better understand factors that promote successful weaning. PMID:28461543

Lung Transcriptomics during Protective Ventilatory Support in Sepsis-Induced Acute Lung Injury

PubMed Central

Acosta-Herrera, Marialbert; Lorenzo-Diaz, Fabian; Pino-Yanes, Maria; Corrales, Almudena; Valladares, Francisco; Klassert, Tilman E.; Valladares, Basilio; Slevogt, Hortense; Ma, Shwu-Fan

2015-01-01

Acute lung injury (ALI) is a severe inflammatory process of the lung. The only proven life-saving support is mechanical ventilation (MV) using low tidal volumes (LVT) plus moderate to high levels of positive end-expiratory pressure (PEEP). However, it is currently unknown how they exert the protective effects. To identify the molecular mechanisms modulated by protective MV, this study reports transcriptomic analyses based on microarray and microRNA sequencing in lung tissues from a clinically relevant animal model of sepsis-induced ALI. Sepsis was induced by cecal ligation and puncture (CLP) in male Sprague-Dawley rats. At 24 hours post-CLP, septic animals were randomized to three ventilatory strategies: spontaneous breathing, LVT (6 ml/kg) plus 10 cmH2O PEEP and high tidal volume (HVT, 20 ml/kg) plus 2 cmH2O PEEP. Healthy, non-septic, non-ventilated animals served as controls. After 4 hours of ventilation, lung samples were obtained for histological examination and gene expression analysis using microarray and microRNA sequencing. Validations were assessed using parallel analyses on existing publicly available genome-wide association study findings and transcriptomic human data. The catalogue of deregulated processes differed among experimental groups. The ‘response to microorganisms’ was the most prominent biological process in septic, non-ventilated and in HVT animals. Unexpectedly, the ‘neuron projection morphogenesis’ process was one of the most significantly deregulated in LVT. Further support for the key role of the latter process was obtained by microRNA studies, as four species targeting many of its genes (Mir-27a, Mir-103, Mir-17-5p and Mir-130a) were found deregulated. Additional analyses revealed 'VEGF signaling' as a central underlying response mechanism to all the septic groups (spontaneously breathing or mechanically ventilated). Based on this data, we conclude that a co-deregulation of 'VEGF signaling' along with 'neuron projection morphogenesis', which have been never anticipated in ALI pathogenesis, promotes lung-protective effects of LVT with high levels of PEEP. PMID:26147972

Abdominal Muscle Activity during Mechanical Ventilation Increases Lung Injury in Severe Acute Respiratory Distress Syndrome

PubMed Central

Zhang, Xianming; Wu, Weiliang; Zhu, Yongcheng; Jiang, Ying; Du, Juan; Chen, Rongchang

2016-01-01

Objective It has proved that muscle paralysis was more protective for injured lung in severe acute respiratory distress syndrome (ARDS), but the precise mechanism is not clear. The purpose of this study was to test the hypothesis that abdominal muscle activity during mechanically ventilation increases lung injury in severe ARDS. Methods Eighteen male Beagles were studied under mechanical ventilation with anesthesia. Severe ARDS was induced by repetitive oleic acid infusion. After lung injury, Beagles were randomly assigned into spontaneous breathing group (BIPAPSB) and abdominal muscle paralysis group (BIPAPAP). All groups were ventilated with BIPAP model for 8h, and the high pressure titrated to reached a tidal volume of 6ml/kg, the low pressure was set at 10 cmH2O, with I:E ratio 1:1, and respiratory rate adjusted to a PaCO2 of 35–60 mmHg. Six Beagles without ventilator support comprised the control group. Respiratory variables, end-expiratory volume (EELV) and gas exchange were assessed during mechanical ventilation. The levels of Interleukin (IL)-6, IL-8 in lung tissue and plasma were measured by qRT-PCR and ELISA respectively. Lung injury scores were determined at end of the experiment. Results For the comparable ventilator setting, as compared with BIPAPSB group, the BIPAPAP group presented higher EELV (427±47 vs. 366±38 ml) and oxygenation index (293±36 vs. 226±31 mmHg), lower levels of IL-6(216.6±48.0 vs. 297.5±71.2 pg/ml) and IL-8(246.8±78.2 vs. 357.5±69.3 pg/ml) in plasma, and lower express levels of IL-6 mRNA (15.0±3.8 vs. 21.2±3.7) and IL-8 mRNA (18.9±6.8 vs. 29.5±7.9) in lung tissues. In addition, less lung histopathology injury were revealed in the BIPAPAP group (22.5±2.0 vs. 25.2±2.1). Conclusion Abdominal muscle activity during mechanically ventilation is one of the injurious factors in severe ARDS, so abdominal muscle paralysis might be an effective strategy to minimize ventilator-induce lung injury. PMID:26745868

Respiratory mechanics to understand ARDS and guide mechanical ventilation.

PubMed

Mauri, Tommaso; Lazzeri, Marta; Bellani, Giacomo; Zanella, Alberto; Grasselli, Giacomo

2017-11-30

As precision medicine is becoming a standard of care in selecting tailored rather than average treatments, physiological measurements might represent the first step in applying personalized therapy in the intensive care unit (ICU). A systematic assessment of respiratory mechanics in patients with the acute respiratory distress syndrome (ARDS) could represent a step in this direction, for two main reasons. Approach and Main results: On the one hand, respiratory mechanics are a powerful physiological method to understand the severity of this syndrome in each single patient. Decreased respiratory system compliance, for example, is associated with low end expiratory lung volume and more severe lung injury. On the other hand, respiratory mechanics might guide protective mechanical ventilation settings. Improved gravitationally dependent regional lung compliance could support the selection of positive end-expiratory pressure and maximize alveolar recruitment. Moreover, the association between driving airway pressure and mortality in ARDS patients potentially underlines the importance of sizing tidal volume on respiratory system compliance rather than on predicted body weight. The present review article aims to describe the main alterations of respiratory mechanics in ARDS as a potent bedside tool to understand severity and guide mechanical ventilation settings, thus representing a readily available clinical resource for ICU physicians.

Antibiotic therapy in ventilator-associated tracheobronchitis: a literature review.

PubMed

Alves, Abel Eduardo; Pereira, José Manuel

2018-03-01

The concept of ventilator-associated tracheobronchitis is controversial; its definition is not unanimously accepted and often overlaps with ventilator-associated pneumonia. Ventilator-associated tracheobronchitis has an incidence similar to that of ventilator-associated pneumonia, with a high prevalence of isolated multiresistant agents, resulting in an increase in the time of mechanical ventilation and hospitalization but without an impact on mortality. The performance of quantitative cultures may allow better diagnostic definition of tracheobronchitis associated with mechanical ventilation, possibly avoiding the overdiagnosis of this condition. One of the major difficulties in differentiating between ventilator-associated tracheobronchitis and ventilator-associated pneumonia is the exclusion of a pulmonary infiltrate by chest radiography; thoracic computed tomography, thoracic ultrasonography, or invasive specimen collection may also be required. The institution of systemic antibiotic therapy does not improve the clinical impact of ventilator-associated tracheobronchitis, particularly in reducing time of mechanical ventilation, hospitalization or mortality, despite the possible reduced progression to ventilator-associated pneumonia. However, there are doubts regarding the methodology used. Thus, considering the high prevalence of tracheobronchitis associated with mechanical ventilation, routine treatment of this condition would result in high antibiotic usage without clear benefits. However, we suggest the institution of antibiotic therapy in patients with tracheobronchitis associated with mechanical ventilation and septic shock and/or worsening of oxygenation, and other auxiliary diagnostic tests should be simultaneously performed to exclude ventilator-associated pneumonia. This review provides a better understanding of the differentiation between tracheobronchitis associated with mechanical ventilation and pneumonia associated with mechanical ventilation, which can significantly decrease the use of antibiotics in critically ventilated patients.

Variable mechanical ventilation

PubMed Central

Fontela, Paula Caitano; Prestes, Renata Bernardy; Forgiarini Jr., Luiz Alberto; Friedman, Gilberto

2017-01-01

Objective To review the literature on the use of variable mechanical ventilation and the main outcomes of this technique. Methods Search, selection, and analysis of all original articles on variable ventilation, without restriction on the period of publication and language, available in the electronic databases LILACS, MEDLINE®, and PubMed, by searching the terms "variable ventilation" OR "noisy ventilation" OR "biologically variable ventilation". Results A total of 36 studies were selected. Of these, 24 were original studies, including 21 experimental studies and three clinical studies. Conclusion Several experimental studies reported the beneficial effects of distinct variable ventilation strategies on lung function using different models of lung injury and healthy lungs. Variable ventilation seems to be a viable strategy for improving gas exchange and respiratory mechanics and preventing lung injury associated with mechanical ventilation. However, further clinical studies are necessary to assess the potential of variable ventilation strategies for the clinical improvement of patients undergoing mechanical ventilation. PMID:28444076

Nasal continuous positive airway pressure (CPAP) for the respiratory care of the newborn infant.

PubMed

Diblasi, Robert M

2009-09-01

Nasal continuous positive airway pressure (CPAP) is a noninvasive form of respiratory assistance that has been used to support spontaneously breathing infants with lung disease for nearly 40 years. Following reports that mechanical ventilation contributes to pulmonary growth arrest and the development of chronic lung disease, there is a renewed interest in using CPAP as the prevailing method for supporting newborn infants. Animal and human research has shown that CPAP is less injurious to the lungs than is mechanical ventilation. The major concepts that embrace lung protection during CPAP are the application of spontaneous breathing at a constant distending pressure and avoidance of intubation and positive-pressure inflations. A major topic for current research focuses on whether premature infants should be supported initially with CPAP following delivery, or after the infant has been extubated following prophylactic surfactant administration. Clinical trials have shown that CPAP reduces the need for intubation/mechanical ventilation and surfactant administration, but it is still unclear whether CPAP reduces chronic lung disease and mortality, compared to modern lung-protective ventilation techniques. Despite the successes, little is known about how best to manage patients using CPAP. It is also unclear whether different strategies or devices used to maintain CPAP play a role in improving outcomes in infants. Nasal CPAP technology has evolved over the last 10 years, and bench and clinical research has evaluated differences in physiologic effects related to these new devices. Ultimately, clinicians' abilities to perceive changes in the pathophysiologic conditions of infants receiving CPAP and the quality of airway care provided are likely to be the most influential factors in determining patient outcomes.

A knowledge-based support system for mechanical ventilation of the lungs. The KUSIVAR concept and prototype.

PubMed

Rudowski, R; Frostell, C; Gill, H

1989-09-01

The KUSIVAR is an expert system for mechanical ventilation of adult patients suffering from respiratory insufficiency. Its main objective is to provide guidance in respirator management. The knowledge base includes both qualitative, rule-based knowledge and quantitative knowledge expressed in the form of mathematical models (expert control) which is used for prediction of arterial gas tensions and optimization purposes. The system is data driven and uses a forward chaining mechanism for rule invocation. The interaction with the user will be performed in advisory, critiquing, semi-automatic and automatic modes. The system is at present in an advanced prototype stage. Prototyping is performed using KEE (Knowledge Engineering Environment) on a Sperry Explorer workstation. For further development and clinical use the expert system will be downloaded to an advanced PC. The system is intended to support therapy with a Siemens-Elema Servoventilator 900 C.

Paid carers' experiences of caring for mechanically ventilated children at home: implications for services and training.

PubMed

Maddox, Christina; Pontin, David

2013-06-01

UK survival rates for long-term mechanically ventilated children have increased and paid carers are trained to care for them at home, however there is limited literature on carers' training needs and experience of sharing care. Using a qualitative abductive design, we purposively sampled experienced carers to generate data via diaries, semi-structured interviews, and researcher reflexive notes. Research ethics approval was granted from NHS and University committees. Five analytical themes emerged - Parent as expert; Role definition tensions; Training and Continuing Learning Needs; Mixed Emotions; Support Mechanisms highlighting the challenges of working in family homes for carers and their associated learning needs. Further work on preparing carers to share feelings with parents, using burnout prevention techniques, and building confidence is suggested. Carers highlight the lack of clinical supervision during their night-working hours. One solution may be to provide access to registered nurse support when working out-of-office hours.

Inhibition of forkhead boxO-specific transcription prevents mechanical ventilation-induced diaphragm dysfunction.

PubMed

Smuder, Ashley J; Sollanek, Kurt J; Min, Kisuk; Nelson, W Bradley; Powers, Scott K

2015-05-01

Mechanical ventilation is a lifesaving measure for patients with respiratory failure. However, prolonged mechanical ventilation results in diaphragm weakness, which contributes to problems in weaning from the ventilator. Therefore, identifying the signaling pathways responsible for mechanical ventilation-induced diaphragm weakness is essential to developing effective countermeasures to combat this important problem. In this regard, the forkhead boxO family of transcription factors is activated in the diaphragm during mechanical ventilation, and forkhead boxO-specific transcription can lead to enhanced proteolysis and muscle protein breakdown. Currently, the role that forkhead boxO activation plays in the development of mechanical ventilation-induced diaphragm weakness remains unknown. This study tested the hypothesis that mechanical ventilation-induced increases in forkhead boxO signaling contribute to ventilator-induced diaphragm weakness. University research laboratory. Young adult female Sprague-Dawley rats. Cause and effect was determined by inhibiting the activation of forkhead boxO in the rat diaphragm through the use of a dominant-negative forkhead boxO adeno-associated virus vector delivered directly to the diaphragm. Our results demonstrate that prolonged (12 hr) mechanical ventilation results in a significant decrease in both diaphragm muscle fiber size and diaphragm-specific force production. However, mechanically ventilated animals treated with dominant-negative forkhead boxO showed a significant attenuation of both diaphragm atrophy and contractile dysfunction. In addition, inhibiting forkhead boxO transcription attenuated the mechanical ventilation-induced activation of the ubiquitin-proteasome system, the autophagy/lysosomal system, and caspase-3. Forkhead boxO is necessary for the activation of key proteolytic systems essential for mechanical ventilation-induced diaphragm atrophy and contractile dysfunction. Collectively, these results suggest that targeting forkhead boxO transcription could be a key therapeutic target to combat ventilator-induced diaphragm dysfunction.

Successful Reinnervation of the Diaphragm After Intercostal to Phrenic Nerve Neurotization in Patients With High Spinal Cord Injury.

PubMed

Nandra, Kulvir S; Harari, Martin; Price, Thea P; Greaney, Patrick J; Weinstein, Michael S

2017-08-01

Our objective in this study was to extend diaphragmatic pacing therapy to include paraplegic patients with high cervical spinal cord injuries between C3 and C5. Diaphragmatic pacing has been used in patients experiencing ventilator-dependent respiratory failure due to spinal cord injury as a means to reduce or eliminate the need for mechanical ventilation. However, this technique relies on intact phrenic nerve function. Recently, phrenic nerve reconstruction with intercostal nerve grafting has expanded the indications for diaphragmatic pacing. Our study aimed to evaluate early outcomes and efficacy of intercostal nerve transfer in diaphragmatic pacing. Four ventilator-dependent patients with high cervical spinal cord injuries were selected for this study. Each patient demonstrated absence of phrenic nerve function via external neck stimulation and laparoscopic diaphragm mapping. Each patient underwent intercostal to phrenic nerve grafting with implantation of a phrenic nerve pacer. The patients were followed, and ventilator dependence was reassessed at 1 year postoperatively. Our primary outcome was measured by the amount of time our patients tolerated off the ventilator per day. We found that all 4 patients have tolerated paced breathing independent of mechanical ventilation, with 1 patient achieving 24 hours of tracheostomy collar. From this study, intercostal to phrenic nerve transfer seems to be a promising approach in reducing or eliminating ventilator support in patients with C3 to C5 high spinal cord injury.

Effects of staff training and electronic event monitoring on long-term adherence to lung-protective ventilation recommendations.

PubMed

Castellanos, Ixchel; Martin, Marcus; Kraus, Stefan; Bürkle, Thomas; Prokosch, Hans-Ulrich; Schüttler, Jürgen; Toddenroth, Dennis

2018-02-01

To investigate long-term effects of staff training and electronic clinical decision support (CDS) on adherence to lung-protective ventilation recommendations. In 2012, group instructions and workshops at two surgical intensive care units (ICUs) started, focusing on standardized protocols for mechanical ventilation and volutrauma prevention. Subsequently implemented CDS functions continuously monitor ventilation parameters, and from 2015 triggered graphical notifications when tidal volume (V T ) violated individual thresholds. To estimate the effects of these educational and technical interventions, we retrospectively analyzed nine years of V T records from routine care. As outcome measures, we calculated relative frequencies of settings that conform to recommendations, case-specific mean excess V T , and total ICU survival. Assessing 571,478 V T records from 10,241 ICU cases indicated that adherence during pressure-controlled ventilation improved significantly after both interventions; the share of conforming V T records increased from 61.6% to 83.0% and then 86.0%. Despite increasing case severity, ICU survival remained nearly constant over time. Staff training effectively improves adherence to lung-protective ventilation strategies. The observed CDS effect seemed less pronounced, although it can easily be adapted to new recommendations. Both interventions, which futures studies could deploy in combination, promise to improve the precision of mechanical ventilation. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Intensive care unit readmission during childhood after preterm birth with respiratory failure.

PubMed

Mourani, Peter M; Kinsella, John P; Clermont, Gilles; Kong, Lan; Perkins, Amy M; Weissfeld, Lisa; Cutter, Gary; Linde-Zwirble, Walter T; Abman, Steven H; Angus, Derek C; Watson, R Scott

2014-04-01

To determine the incidence and risk factors for readmission to the intensive care unit (ICU) among preterm infants who required mechanical ventilation at birth. We studied preterm newborns (birth weight 500-1250 g) who required mechanical ventilation at birth and were enrolled in a multicenter trial of inhaled nitric oxide therapy. Patients were assessed up to 4.5 years of age via annual in-person evaluations and structured telephone interviews. Univariate and multivariable analyses of baseline and birth hospitalization predictors of ICU readmission were performed. Of 512 subjects providing follow-up data, 58% were readmitted to the hospital (51% of these had multiple readmissions, averaging 3.9 readmissions per subject), 19% were readmitted to an ICU, and 12% required additional mechanical ventilation support. In univariate analyses, ICU readmission was more common among male subjects (OR 2.01; 95% CI 1.27-3.18), infants with grade 3-4 intracranial hemorrhage (OR 2.13; 95% CI 1.23-3.69), increasing duration of birth hospitalization (OR 1.01 per day; 95% CI 1.00-1.02), and prolonged oxygen therapy (OR 1.01 per day; 95% CI 1.00-1.01). In the first year after birth hospitalization, children readmitted to an ICU incurred greater health care costs (median $69,700 vs $30,200 for subjects admitted to the ward and $9600 for subjects never admitted). Small preterm infants who were mechanically ventilated at birth have substantial risk for readmission to an ICU and late mechanical ventilation, require extensive health care resources, and incur high treatment costs. Copyright © 2014 Mosby, Inc. All rights reserved.

Correlation between the single, high dose of ingested baclofen and clinical symptoms.

PubMed

Anand, Jacek Sein; Zając, Maciej; Waldman, Wojciech; Wojtyła, Andrzej; Biliński, Przemysław; Jaworska-Łuczak, Barbara

2017-12-23

Baclofen is a drug used mainly to treat muscle spasticity. Its overdose can lead to life-threatening clinical symptoms, including acute respiratory failure requiring mechanical ventilation. The aim of this study was to assess the prevalence of selected clinical symptoms associated with baclofen poisoning comparing to an ingested dose. 60 cases of oral baclofen poisoning were analyzed. Gender, age distribution, and correlation between the dose of ingested baclofen were studied, as well as and following clinical parameters: degree of altered consciousness, heart rate, blood pressure, presence of acute respiratory failure, duration of mechanical ventilation, and presence of psychotic symptoms. The study found statistically significant correlations between dosage of ingested baclofen and presence of acute respiratory failure, as well as duration of mechanical ventilation. No statistically significant correlations were found between the dose of ingested baclofen and presence of hypertension, bradycardia, acute psychotic symptoms, or level of consciousness disturbance. However, it was found that patients who suffered from hypertension, bradycardia, and altered mental status ingested a larger dose of baclofen. There is a statistically significant correlation between the dose of ingested baclofen and the presence of acute respiratory failure, and duration of mechanical ventilation. Patients who have taken a single dose of baclofen of 200 mg, or higher, should be managed in centres able to provide continuous monitoring of life functions. Those with a higher level of a single dose of baclofen ingestion (>500 mg), should be hospitalized in a Toxicology Unit or Intensive Care Unit able to provide airway support and mechanical ventilation.

A model of neonatal tidal liquid ventilation mechanics.

PubMed

Costantino, M L; Fiore, G B

2001-09-01

Tidal liquid ventilation (TLV) with perfluorocarbons (PFC) has been proposed to treat surfactant-deficient lungs of preterm neonates, since it may prevent pulmonary instability by abating saccular surface tension. With a previous model describing gas exchange, we showed that ventilator settings are crucial for CO(2) scavenging during neonatal TLV. The present work is focused on some mechanical aspects of neonatal TLV that were hardly studied, i.e. the distribution of mechanical loads in the lungs, which is expected to differ substantially from gas ventilation. A new computational model is presented, describing pulmonary PFC hydrodynamics, where viscous losses, kinetic energy changes and lung compliance are accounted for. The model was implemented in a software package (LVMech) aimed at calculating pressures (and approximately estimate shear stresses) within the bronchial tree at different ventilator regimes. Simulations were run taking the previous model's outcomes into account. Results show that the pressure decrease due to high saccular compliance may compensate for the increased pressure drops due to PFC viscosity, and keep airway pressure low. Saccules are exposed to pressures remarkably different from those at the airway opening; during expiration negative pressures, which may cause airway collapse, are moderate and appear in the upper airways only. Delivering the fluid with a slightly smoothed square flow wave is convenient with respect to a sine wave. The use of LVMech allows to familiarize with LV treatment management taking the lungs' mechanical load into account, consistently with a proper respiratory support.

Response of Preterm Infants to 2 Noninvasive Ventilatory Support Systems: Nasal CPAP and Nasal Intermittent Positive-Pressure Ventilation.

PubMed

Silveira, Carmen Salum Thomé; Leonardi, Kamila Maia; Melo, Ana Paula Carvalho Freire; Zaia, José Eduardo; Brunherotti, Marisa Afonso Andrade

2015-12-01

Noninvasive ventilation (NIV) in preterm infants is currently applied using intermittent positive pressure (2 positive-pressure levels) or in a conventional manner (one pressure level). However, there are no studies in the literature comparing the chances of failure of these NIV methods. The aim of this study was to evaluate the occurrence of failure of 2 noninvasive ventilatory support systems in preterm neonates over a period of 48 h. A randomized, prospective, clinical study was conducted on 80 newborns (gestational age < 37 weeks, birthweight < 2,500 g). The infants were randomized into 2 groups: 40 infants were treated with nasal CPAP and 40 infants with nasal intermittent positive-pressure ventilation (NIPPV). The occurrence of apnea, progression of respiratory distress, nose bleeding, and agitation was defined as ventilation failure. The need for intubation and re-intubation after failure was also observed. There were no significant differences in birth characteristics between groups. Ventilatory support failure was observed in 25 (62.5%) newborns treated with nasal CPAP and in 12 (30%) newborns treated with NIPPV, indicating an association between NIV failure and the absence of intermittent positive pressure (odds ratio [OR] 1.22, P < .05). Apnea (32.5%) was the main reason for nasal CPAP failure. After failure, 25% (OR 0.33) of the newborns receiving nasal CPAP and 12.5% (OR 0.14) receiving NIPPV required invasive mechanical ventilation. Ventilatory support failure was significantly more frequent when nasal CPAP was used. Copyright © 2015 by Daedalus Enterprises.

[Non-invasive mechanical ventilation in postoperative patients. A clinical review].

PubMed

Esquinas, A M; Jover, J L; Úbeda, A; Belda, F J

2015-11-01

Non-invasive ventilation (NIV) is a method of ventilatory support that is increasing in importance day by day in the management of postoperative respiratory failure. Its role in the prevention and treatment of atelectasis is particularly important in the in the period after thoracic and abdominal surgeries. Similarly, in the transplanted patient, NIV can shorten the time of invasive mechanical ventilation, reducing the risk of infectious complications in these high-risk patients. It has been performed A systematic review of the literature has been performed, including examining the technical, clinical experiences and recommendations concerning the application of NIV in the postoperative period. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Humidification on Ventilated Patients: Heated Humidifications or Heat and Moisture Exchangers?

PubMed Central

Cerpa, F; Cáceres, D; Romero-Dapueto, C; Giugliano-Jaramillo, C; Pérez, R; Budini, H; Hidalgo, V; Gutiérrez, T; Molina, J; Keymer, J

2015-01-01

The normal physiology of conditioning of inspired gases is altered when the patient requires an artificial airway access and an invasive mechanical ventilation (IMV). The endotracheal tube (ETT) removes the natural mechanisms of filtration, humidification and warming of inspired air. Despite the noninvasive ventilation (NIMV) in the upper airways, humidification of inspired gas may not be optimal mainly due to the high flow that is being created by the leakage compensation, among other aspects. Any moisture and heating deficit is compensated by the large airways of the tracheobronchial tree, these are poorly suited for this task, which alters mucociliary function, quality of secretions, and homeostasis gas exchange system. To avoid the occurrence of these events, external devices that provide humidification, heating and filtration have been developed, with different degrees of evidence that support their use. PMID:26312102

Humidification on Ventilated Patients: Heated Humidifications or Heat and Moisture Exchangers?

PubMed

Cerpa, F; Cáceres, D; Romero-Dapueto, C; Giugliano-Jaramillo, C; Pérez, R; Budini, H; Hidalgo, V; Gutiérrez, T; Molina, J; Keymer, J

2015-01-01

The normal physiology of conditioning of inspired gases is altered when the patient requires an artificial airway access and an invasive mechanical ventilation (IMV). The endotracheal tube (ETT) removes the natural mechanisms of filtration, humidification and warming of inspired air. Despite the noninvasive ventilation (NIMV) in the upper airways, humidification of inspired gas may not be optimal mainly due to the high flow that is being created by the leakage compensation, among other aspects. Any moisture and heating deficit is compensated by the large airways of the tracheobronchial tree, these are poorly suited for this task, which alters mucociliary function, quality of secretions, and homeostasis gas exchange system. To avoid the occurrence of these events, external devices that provide humidification, heating and filtration have been developed, with different degrees of evidence that support their use.

Academic Emergency Medicine Physicians' Knowledge of Mechanical Ventilation.

PubMed

Wilcox, Susan R; Strout, Tania D; Schneider, Jeffrey I; Mitchell, Patricia M; Smith, Jessica; Lutfy-Clayton, Lucienne; Marcolini, Evie G; Aydin, Ani; Seigel, Todd A; Richards, Jeremy B

2016-05-01

Although emergency physicians frequently intubate patients, management of mechanical ventilation has not been emphasized in emergency medicine (EM) education or clinical practice. The objective of this study was to quantify EM attendings' education, experience, and knowledge regarding mechanical ventilation in the emergency department. We developed a survey of academic EM attendings' educational experiences with ventilators and a knowledge assessment tool with nine clinical questions. EM attendings at key teaching hospitals for seven EM residency training programs in the northeastern United States were invited to participate in this survey study. We performed correlation and regression analyses to evaluate the relationship between attendings' scores on the assessment instrument and their training, education, and comfort with ventilation. Of 394 EM attendings surveyed, 211 responded (53.6%). Of respondents, 74.5% reported receiving three or fewer hours of ventilation-related education from EM sources over the past year and 98 (46%) reported receiving between 0-1 hour of education. The overall correct response rate for the assessment tool was 73.4%, with a standard deviation of 19.9. The factors associated with a higher score were completion of an EM residency, prior emphasis on mechanical ventilation during one's own residency, working in a setting where an emergency physician bears primary responsibility for ventilator management, and level of comfort with managing ventilated patients. Physicians' comfort was associated with the frequency of ventilator changes and EM management of ventilation, as well as hours of education. EM attendings report caring for mechanically ventilated patients frequently, but most receive fewer than three educational hours a year on mechanical ventilation, and nearly half receive 0-1 hour. Physicians' performance on an assessment tool for mechanical ventilation is most strongly correlated with their self-reported comfort with mechanical ventilation.

Pressure support versus T-tube for weaning from mechanical ventilation in adults.

PubMed

Ladeira, Magdaline T; Vital, Flávia M R; Andriolo, Régis B; Andriolo, Brenda N G; Atallah, Alvaro N; Peccin, Maria S

2014-05-27

Mechanical ventilation is important in caring for patients with critical illness. Clinical complications, increased mortality, and high costs of health care are associated with prolonged ventilatory support or premature discontinuation of mechanical ventilation. Weaning refers to the process of gradually or abruptly withdrawing mechanical ventilation. The weaning process begins after partial or complete resolution of the underlying pathophysiology precipitating respiratory failure and ends with weaning success (successful extubation in intubated patients or permanent withdrawal of ventilatory support in tracheostomized patients). To evaluate the effectiveness and safety of two strategies, a T-tube and pressure support ventilation, for weaning adult patients with respiratory failure that required invasive mechanical ventilation for at least 24 hours, measuring weaning success and other clinically important outcomes. We searched the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 6); MEDLINE (via PubMed) (1966 to June 2012); EMBASE (January 1980 to June 2012); LILACS (1986 to June 2012); CINAHL (1982 to June 2012); SciELO (from 1997 to August 2012); thesis repository of CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) (http://capesdw.capes.gov.br/capesdw/) (August 2012); and Current Controlled Trials (August 2012).We reran the search in December 2013. We will deal with any studies of interest when we update the review. We included randomized controlled trials (RCTs) that compared a T-tube with pressure support (PS) for the conduct of spontaneous breathing trials and as methods of gradual weaning of adult patients with respiratory failure of various aetiologies who received invasive mechanical ventilation for at least 24 hours. Two authors extracted data and assessed the methodological quality of the included studies. Meta-analyses using the random-effects model were conducted for nine outcomes. Relative risk (RR) and mean difference (MD) or standardized mean difference (SMD) were used to estimate the treatment effect, with 95% confidence intervals (CI). We included nine RCTs with 1208 patients; 622 patients were randomized to a PS spontaneous breathing trial (SBT) and 586 to a T-tube SBT. The studies were classified into three categories of weaning: simple, difficult, and prolonged. Four studies placed patients in two categories of weaning. Pressure support ventilation (PSV) and a T-tube were used directly as SBTs in four studies (844 patients, 69.9% of the sample). In 186 patients (15.4%) both interventions were used along with gradual weaning from mechanical ventilation; the PS was gradually decreased, twice a day, until it was minimal and periods with a T-tube were gradually increased to two and eight hours for patients with difficult and prolonged weaning. In two studies (14.7% of patients) the PS was lowered to 2 to 4 cm H2O and 3 to 5 cm H2O based on ventilatory parameters until the minimal PS levels were reached. PS was then compared to the trial with the T-tube (TT).We identified 33 different reported outcomes in the included studies; we took 14 of them into consideration and performed meta-analyses on nine. With regard to the sequence of allocation generation, allocation concealment, selective reporting and attrition bias, no study presented a high risk of bias. We found no clear evidence of a difference between PS and TT for weaning success (RR 1.07, 95% CI 0.97 to 1.17, 9 studies, low quality of evidence), intensive care unit (ICU) mortality (RR 0.81, 95% CI 0.53 to 1.23, 5 studies, low quality of evidence), reintubation (RR 0.92, 95% CI 0.66 to 1.26, 7 studies, low quality evidence), ICU and long-term weaning unit (LWU) length of stay (MD -7.08 days, 95% CI -16.26 to 2.1, 2 studies, low quality of evidence) and pneumonia (RR 0.67, 95% CI 0.08 to 5.85, 2 studies, low quality of evidence). PS was significantly superior to the TT for successful SBTs (RR 1.09, 95% CI 1.02 to 1.17, 4 studies, moderate quality of evidence). Four studies reported on weaning duration, however we were unable to combined the study data because of differences in how the studies presented their data. One study was at high risk of other bias and four studies were at high risk for detection bias. Three studies reported that the weaning duration was shorter with PS, and in one study the duration was shorter in patients with a TT. To date, we have found evidence of generally low quality from studies comparing pressure support ventilation (PSV) and with a T-tube. The effects on weaning success, ICU mortality, reintubation, ICU and LWU length of stay, and pneumonia were imprecise. However, PSV was more effective than a T-tube for successful spontaneous breathing trials (SBTs) among patients with simple weaning. Based on the findings of single trials, three studies presented a shorter weaning duration in the group undergoing PS SBT, however a fourth study found a shorter weaning duration with a T-tube.

Daily Goals Formulation and Enhanced Visualization of Mechanical Ventilation Variance Improves Mechanical Ventilation Score.

PubMed

Walsh, Brian K; Smallwood, Craig; Rettig, Jordan; Kacmarek, Robert M; Thompson, John; Arnold, John H

2017-03-01

The systematic implementation of evidence-based practice through the use of guidelines, checklists, and protocols mitigates the risks associated with mechanical ventilation, yet variation in practice remains prevalent. Recent advances in software and hardware have allowed for the development and deployment of an enhanced visualization tool that identifies mechanical ventilation goal variance. Our aim was to assess the utility of daily goal establishment and a computer-aided visualization of variance. This study was composed of 3 phases: a retrospective observational phase (baseline) followed by 2 prospective sequential interventions. Phase I intervention comprised daily goal establishment of mechanical ventilation. Phase II intervention was the setting and monitoring of daily goals of mechanical ventilation with a web-based data visualization system (T3). A single score of mechanical ventilation was developed to evaluate the outcome. The baseline phase evaluated 130 subjects, phase I enrolled 31 subjects, and phase II enrolled 36 subjects. There were no differences in demographic characteristics between cohorts. A total of 171 verbalizations of goals of mechanical ventilation were completed in phase I. The use of T3 increased by 87% from phase I. Mechanical ventilation score improved by 8.4% in phase I and 11.3% in phase II from baseline ( P = .032). The largest effect was in the low risk V T category, with a 40.3% improvement from baseline in phase I, which was maintained at 39% improvement from baseline in phase II ( P = .01). mechanical ventilation score was 9% higher on average in those who survived. Daily goal formation and computer-enhanced visualization of mechanical ventilation variance were associated with an improvement in goal attainment by evidence of an improved mechanical ventilation score. Further research is needed to determine whether improvements in mechanical ventilation score through a targeted, process-oriented intervention will lead to improved patient outcomes. (ClinicalTrials.gov registration NCT02184208.). Copyright © 2017 by Daedalus Enterprises.

Clinical assessment of auto-positive end-expiratory pressure by diaphragmatic electrical activity during pressure support and neurally adjusted ventilatory assist.

PubMed

Bellani, Giacomo; Coppadoro, Andrea; Patroniti, Nicolò; Turella, Marta; Arrigoni Marocco, Stefano; Grasselli, Giacomo; Mauri, Tommaso; Pesenti, Antonio

2014-09-01

Auto-positive end-expiratory pressure (auto-PEEP) may substantially increase the inspiratory effort during assisted mechanical ventilation. Purpose of this study was to assess whether the electrical activity of the diaphragm (EAdi) signal can be reliably used to estimate auto-PEEP in patients undergoing pressure support ventilation and neurally adjusted ventilatory assist (NAVA) and whether NAVA was beneficial in comparison with pressure support ventilation in patients affected by auto-PEEP. In 10 patients with a clinical suspicion of auto-PEEP, the authors simultaneously recorded EAdi, airway, esophageal pressure, and flow during pressure support and NAVA, whereas external PEEP was increased from 2 to 14 cm H2O. Tracings were analyzed to measure apparent "dynamic" auto-PEEP (decrease in esophageal pressure to generate inspiratory flow), auto-EAdi (EAdi value at the onset of inspiratory flow), and IDEAdi (inspiratory delay between the onset of EAdi and the inspiratory flow). The pressure necessary to overcome auto-PEEP, auto-EAdi, and IDEAdi was significantly lower in NAVA as compared with pressure support ventilation, decreased with increase in external PEEP, although the effect of external PEEP was less pronounced in NAVA. Both auto-EAdi and IDEAdi were tightly correlated with auto-PEEP (r = 0.94 and r = 0.75, respectively). In the presence of auto-PEEP at lower external PEEP levels, NAVA was characterized by a characteristic shape of the airway pressure. In patients with auto-PEEP, NAVA, compared with pressure support ventilation, led to a decrease in the pressure necessary to overcome auto-PEEP, which could be reliably monitored by the electrical activity of the diaphragm before inspiratory flow onset (auto-EAdi).

An evaluation of bubble-CPAP in a neonatal unit in a developing country: effective respiratory support that can be applied by nurses.

PubMed

Koyamaibole, Lanieta; Kado, Joseph; Qovu, Josaia D; Colquhoun, Samantha; Duke, Trevor

2006-08-01

To describe the implementation of bubble-CPAP in a referral hospital in a developing country and to investigate: the feasibility of nurses implementing bubble-CPAP and the impact of bubble-CPAP on need for mechanical ventilation and mortality. Retrospective evaluation of prospectively collected data from two time periods: 18 months before and 18 months after the introduction of bubble-CPAP. The introduction of bubble-CPAP was associated with a 50 per cent reduction in the need for mechanical ventilation; from 113 of 1,106 (10.2 per cent) prior to bubble-CPAP to 70 of 1,382 (5.1%) after introduction of CPAP (chi2, p<0.001). In the 18 months prior to bubble-CPAP there were 79 deaths (case fatality of 7.1 per cent). In the 18 months after bubble-CPAP there were 74 deaths (CF 5.4 per cent), relative risk: 0.75 (0.55-1.02, chi2, p=0.065). Nurses could safely apply bubble-CPAP after 1-2 months of on-the-job training. Equipment for Bubble-CPAP cost 15 per cent of the cost of the cheapest mechanical ventilator. The introduction of bubble-CPAP substantially reduced the need for mechanical ventilation, with no difference in mortality. In models of neonatal care for resource-limited countries, bubble-CPAP may be the first type of ventilatory support that is recommended. Its low cost and safety when administered by nurses makes it ideal for this purpose. Bubble-CPAP has the potential for being available at even lower cost than the current commercially available bubble systems used in this study.

Pleural liquid and kinetic friction coefficient of mesothelium after mechanical ventilation.

PubMed

Bodega, Francesca; Sironi, Chiara; Porta, Cristina; Zocchi, Luciano; Agostoni, Emilio

2015-01-15

Volume and protein concentration of pleural liquid in anesthetized rabbits after 1 or 3h of mechanical ventilation, with alveolar pressure equal to atmospheric at end expiration, were compared to those occurring after spontaneous breathing. Moreover, coefficient of kinetic friction between samples of visceral and parietal pleura, obtained after spontaneous or mechanical ventilation, sliding in vitro at physiological velocity under physiological load, was determined. Volume of pleural liquid after mechanical ventilation was similar to that previously found during spontaneous ventilation. This finding is contrary to expectation of Moriondo et al. (2005), based on measurement of lymphatic and interstitial pressure. Protein concentration of pleural liquid after mechanical ventilation was also similar to that occurring after spontaneous ventilation. Coefficient of kinetic friction after mechanical ventilation was 0.023±0.001, similar to that obtained after spontaneous breathing. Copyright © 2014 Elsevier B.V. All rights reserved.

Lung-protective mechanical ventilation does not protect against acute kidney injury in patients without lung injury at onset of mechanical ventilation.

PubMed

Cortjens, Bart; Royakkers, Annick A N M; Determann, Rogier M; van Suijlen, Jeroen D E; Kamphuis, Stephan S; Foppen, Jannetje; de Boer, Anita; Wieland, Cathrien W; Spronk, Peter E; Schultz, Marcus J; Bouman, Catherine S C

2012-06-01

Preclinical and clinical studies suggest that mechanical ventilation contributes to the development of acute kidney injury (AKI), particularly in the setting of lung-injurious ventilator strategies. To determine whether ventilator settings in critically ill patients without acute lung injury (ALI) at onset of mechanical ventilation affect the development of AKI. Secondary analysis of a randomized controlled trial (N = 150), comparing conventional tidal volume (V(T), 10 mL/kg) with low tidal volume (V(T), 6 mL/kg) mechanical ventilation in critically ill patients without ALI at randomization. During the first 5 days of mechanical ventilation, the RIFLE class was determined daily, whereas neutrophil gelatinase-associated lipocalin and cystatin C levels were measured in plasma collected on days 0, 2, and 4. Eighty-six patients had no AKI at inclusion, and 18 patients (21%) subsequently developed AKI, but without significant difference between ventilation strategies. (Cumulative hazard, 0.26 vs 0.23; P = .88.) The courses of neutrophil gelatinase-associated lipocalin and cystatin C plasma levels did not differ significantly between randomization groups. In the present study in critically patients without ALI at onset of mechanical ventilation, lower tidal volume ventilation did not reduce the development or worsening of AKI compared with conventional tidal volume ventilation. Copyright © 2012 Elsevier Inc. All rights reserved.

A dual closed-loop control system for mechanical ventilation.

PubMed

Tehrani, Fleur; Rogers, Mark; Lo, Takkin; Malinowski, Thomas; Afuwape, Samuel; Lum, Michael; Grundl, Brett; Terry, Michael

2004-04-01

Closed-loop mechanical ventilation has the potential to provide more effective ventilatory support to patients with less complexity than conventional ventilation. The purpose of this study was to investigate the effectiveness of an automatic technique for mechanical ventilation. Two closed-loop control systems for mechanical ventilation are combined in this study. In one of the control systems several physiological data are used to automatically adjust the frequency and tidal volume of breaths of a patient. This method, which is patented under US Patent number 4986268, uses the criterion of minimal respiratory work rate to provide the patient with a natural pattern of breathing. The inputs to the system include data representing CO2 and O2 levels of the patient as well as respiratory compliance and airway resistance. The I:E ratio is adjusted on the basis of the respiratory time constant to allow for effective emptying of the lungs in expiration and to avoid intrinsic positive end expiratory pressure (PEEP). This system is combined with another closed-loop control system for automatic adjustment of the inspired fraction of oxygen of the patient. This controller uses the feedback of arterial oxygen saturation of the patient and combines a rapid stepwise control procedure with a proportional-integral-derivative (PID) control algorithm to automatically adjust the oxygen concentration in the patient's inspired gas. The dual closed-loop control system has been examined by using mechanical lung studies, computer simulations and animal experiments. In the mechanical lung studies, the ventilation controller adjusted the breathing frequency and tidal volume in a clinically appropriate manner in response to changes in respiratory mechanics. The results of computer simulations and animal studies under induced disturbances showed that blood gases were returned to the normal physiologic range in less than 25 s by the control system. In the animal experiments understeady-state conditions, the maximum standard deviations of arterial oxygen saturation and the end-tidal partial pressure of CO2 were +/- 1.76% and +/- 1.78 mmHg, respectively. The controller maintained the arterial blood gases within normal limits under steady-state conditions and the transient response of the system was robust under various disturbances. The results of the study have showed that the proposed dual closed-loop technique has effectively controlled mechanical ventilation under different test conditions.

[Reflections on the use of non-invasive mechanical ventilation in acute respiratory failure].

PubMed

Scala, Raffaele

2012-12-01

Given its prevalence into the clinical practice, non-invasive ventilation (NIV) can be included among the cornerstones of medicine. Just think of the acute applications of NIV which are in constant expansion, from COPD exacerbation to severe de novo hypoxemia, from postoperative distress to extra-hospital use in acute pulmonary edema, from ongoing support of interventional procedures to delicate strategies for end of life in terminally ill oncologic and non-oncologic patients. The thought should be focused on how, by whom, where and to whom is delivered this mode of artificial ventilation to avoid the risk of trivialization and flattening.

Implementation of a Goal-Directed Mechanical Ventilation Order Set Driven by Respiratory Therapists Improves Compliance With Best Practices for Mechanical Ventilation.

PubMed

Radosevich, Misty A; Wanta, Brendan T; Meyer, Todd J; Weber, Verlin W; Brown, Daniel R; Smischney, Nathan J; Diedrich, Daniel A

2017-01-01

Data regarding best practices for ventilator management strategies that improve outcomes in acute respiratory distress syndrome (ARDS) are readily available. However, little is known regarding processes to ensure compliance with these strategies. We developed a goal-directed mechanical ventilation order set that included physician-specified lung-protective ventilation and oxygenation goals to be implemented by respiratory therapists (RTs). We sought as a primary outcome to determine whether an RT-driven order set with predefined oxygenation and ventilation goals could be implemented and associated with improved adherence with best practice. We evaluated 1302 patients undergoing invasive mechanical ventilation (1693 separate episodes of invasive mechanical ventilation) prior to and after institution of a standardized, goal-directed mechanical ventilation order set using a controlled before-and-after study design. Patient-specific goals for oxygenation partial pressure of oxygen in arterial blood (Pao 2 ), ARDS Network [Net] positive end-expiratory pressure [PEEP]/fraction of inspired oxygen [Fio 2 ] table use) and ventilation (pH, partial pressure of carbon dioxide) were selected by prescribers and implemented by RTs. Compliance with the new mechanical ventilation order set was high: 88.2% compliance versus 3.8% before implementation of the order set ( P < .001). Adherence to the PEEP/Fio 2 table after implementation of the order set was significantly greater (86.0% after vs 82.9% before, P = .02). There was no difference in duration of mechanical ventilation, intensive care unit (ICU) length of stay, and in-hospital or ICU mortality. A standardized best practice mechanical ventilation order set can be implemented by a multidisciplinary team and is associated with improved compliance to written orders and adherence to the ARDSNet PEEP/Fio 2 table.

Effect of acute kidney injury on weaning from mechanical ventilation in critically ill patients.

PubMed

Vieira, José M; Castro, Isac; Curvello-Neto, Américo; Demarzo, Sérgio; Caruso, Pedro; Pastore, Laerte; Imanishe, Marina H; Abdulkader, Regina C R M; Deheinzelin, Daniel

2007-01-01

Acute kidney injury (AKI) worsens outcome in various scenarios. We sought to investigate whether the occurrence of AKI has any effect on weaning from mechanical ventilation. Observational, retrospective study in a 23-bed medical/surgical intensive care unit (ICU) in a cancer hospital from January to December 2003. The inclusion criterion was invasive mechanical ventilation for > or =48 hrs. AKI was defined as at least one measurement of serum creatinine of > or =1.5 mg/dL during the ICU stay. Patients were then separated into AKI and non-AKI patients (control group). The criterion for weaning was the combination of positive end-expiratory pressure of < or =8 cm H2O, pressure support of < or =10 cm H2O, and Fio2 of < or =0.4, with spontaneous breathing. The primary end point was duration of weaning and the secondary end points were rate of weaning failure, total length of mechanical ventilation, length of stay in the ICU, and ICU mortality. A total of 140 patients were studied: 93 with AKI and 47 controls. The groups were similar in regard to age, sex, and type of tumor. Diagnosis of acute lung injury/acute respiratory distress syndrome as cause of respiratory failure and Simplified Acute Physiology Score II at admission did not differ between groups. During ICU stay, AKI patients had markers of more severe disease: increased occurrence of severe sepsis or septic shock, higher number of antibiotics, and longer use of vasoactive drugs. The median (interquartile range) duration of mechanical ventilation (10 [6-17] vs. 7 [2-12] days, p = .017) and duration of weaning from mechanical ventilation (41 [16-97] vs. 21 [7-33.5] hrs, p = .018) were longer in AKI patients compared with control patients. Cox regression analysis demonstrated that a > or =85% increase in baseline serum creatinine (hazard rate, 2.30; 95% confidence interval, 1.30-4.08), oliguria (hazard rate, 2.51; 95% confidence interval, 1.24-5.08), and the number of antibiotics (hazard rate, 2.64; 95% confidence interval, 1.51-4.63) predicted longer duration of weaning. The length of ICU stay and ICU mortality rate were significantly greater in the AKI patients. After adjusting for Simplified Acute Physiology Score II, oliguria (odds ratio, 30.8; 95% confidence interval, 7.7-123.0) remained as a strong risk factor for mortality. This study shows that renal dysfunction has serious consequences in the duration of mechanical ventilation, weaning from mechanical ventilation, and mortality in critically ill cancer patients.

Accuracy of tidal volume delivered by home mechanical ventilation during mouthpiece ventilation

PubMed Central

Prigent, Helene; Falaize, Line; Leroux, Karl; Santos, Dante; Vaugier, Isabelle; Orlikowski, David; Lofaso, Frederic

2016-01-01

The aim of our study was to evaluate efficacy and reliability of currently available ventilators for mouthpiece ventilation (MPV). Five life-support home ventilators were assessed in a bench test using different settings simulating the specificities of MPV, such as intermittent circuit disconnection and presence of continuous leaks. The intermittent disconnection of the circuit caused relevant swings in the delivered tidal volume (VT), showing a VT overshoot during the disconnection periods and a VT decrease when the interface was reconnected to the test lung. The five ventilators showed substantial differences in the number of respiratory cycles necessary to reach a stable VT in the volume-controlled setting, ranging from 1.3 ± 0.6 to 7.3 ± 1.2 cycles. These differences were less accentuated in the volume-assisted setting (MPV-dedicated mode, when available). Our data show large differences in the capacity of the different ventilators to deal with the rapidly changing respiratory load features that characterize MPV, which can be further accentuated according to the used ventilator setting. The dedicated MPV modes allow improvement in the performance of ventilators only in some defined situations. This has practical consequences for the choice of the ventilator to be used for MPV in a specific patient. PMID:27146811

Home Mechanical Ventilation: A 12-Year Population-Based Retrospective Cohort Study.

PubMed

Povitz, Marcus; Rose, Louise; Shariff, Salimah Z; Leonard, Sean; Welk, Blayne; Jenkyn, Krista Bray; Leasa, David J; Gershon, Andrea S

2018-04-01

Increasing numbers of individuals are being initiated on home mechanical ventilation, including noninvasive (bi-level) and invasive mechanical ventilation delivered via tracheostomy due to chronic respiratory failure to enable symptom management and promote quality of life. Given the high care needs of these individuals, a better understanding of the indications for home mechanical ventilation, and health-care utilization is needed. We performed a retrospective cohort study using provincial health administrative data from Ontario, Canada (population ∼13,000,000). Home mechanical ventilation users were characterized using health administrative data to determine the indications for home mechanical ventilation, the need for acute care at the time of ventilation approval, and their health service use and mortality rates following approval. The annual incidence of home mechanical ventilation approval rose from 1.8/100,000 in 2000 to 5.0/100,000 in 2012, or an annual increase of approximately 0.3/100,000 persons/y. The leading indications were neuromuscular disease, thoracic restriction, and COPD. The indication for the remainder could not be determined due to limitations of the administrative databases. Of the 4,670 individuals, 23.0% commenced home mechanical ventilation following an acute care hospitalization. Among individuals who survived at least 1 y, fewer required hospitalization in the year that followed home mechanical ventilation approval (29.9% vs 39.8%) as compared with the year prior. Utilization of home mechanical ventilation is increasing in Ontario, Canada, and further study is needed to clarify the factors contributing to this and to further optimize utilization of health-care resources. Copyright © 2018 by Daedalus Enterprises.

Glutamine supplemented parenteral nutrition to prevent ventilator-associated pneumonia in the intensive care unit.

PubMed

Aydoğmuş, Meltem Türkay; Tomak, Yakup; Tekin, Murat; Katı, Ismail; Hüseyinoğlu, Urfettin

2012-12-01

Ventilator-associated pneumonia (VAP) is a form of nosocomial pneumonia that increases patient morbidity and mortality, length of hospital stay, and healthcare costs. Glutamine preserves the intestinal mucosal structure, increases immune function, and reduces harmful changes in gut permeability in patients receiving total parenteral nutrition (TPN). We hypothesized that TPN supplemented by glutamine might prevent the development of VAP in patients on mechanical ventilator support in the intensive care unit (ICU). With the approval of the ethics committee and informed consent from relatives, 60 patients who were followed in the ICU with mechanical ventilator support were included in our study. Patients were divided into three groups. The first group received enteral nutrition (n=20), and the second was prescribed TPN (n=20) while the third group was given glutamine-supplemented TPN (n=20). C-reactive protein (CRP), sedimentation rate, body temperature, development of purulent secretions, increase in the amount of secretions, changes in the characteristics of secretions and an increase in requirement of deep tracheal aspiration were monitored for seven days by daily examination and radiographs. No statistically significant difference was found among groups in terms of development of VAP (p=0.622). Although VAP developed at a lower rate in the glutamine-supplemented TPN group, no statistically significant difference was found among any of the groups. Glutamine-supplemented TPN may have no superiority over unsupplemented enteral and TPN in preventing VAP.

Transitions to Home Mechanical Ventilation: The Experiences of Canadian Ventilator-Assisted Adults and Their Family Caregivers.

PubMed

Dale, Craig M; King, Judy; Nonoyama, Mika; Carbone, Sarah; McKim, Douglas; Road, Jeremy; Rose, Louise

2017-12-28

Several studies have explored the experience of ventilator-assisted individual (VAIs) living at home with family caregivers. However, few explore the experiences of these individuals as they transition from a hospital setting to living at home with a view to identifying modifiable processes that could optimize transition. This descriptive, qualitative study sought to elucidate barriers to, and facilitators of, transition to home mechanical ventilation (HMV) from the perspective of Canadian VAIs and their family caregivers. Participant recruitment occurred through hospital and community respiratory clinicians based in the four Canadian provinces of Alberta, British Columbia, Ontario, and Saskatchewan. Semi-structured telephone or face-to-face interviews at home were undertaken with 33 individuals including 19 VAIs and 14 family caregivers between 3 to 24 months of transitioning to HMV. Interview data was analyzed using content analysis. Formal teaching of knowledge and skills relevant to HMV within the hospital setting prior to transition was perceived as having an immediate and enduring positive impact on transition. However, family-clinician conflict, information gaps, and persistent lack of trained personal support workers (PSWs) to provide care in the home contributed to maladjustment relating to transition. Participants strongly recommended improved transitional care in the form of respiratory health professional telephone support, home outreach, in addition to training of PSWs. Transition to HMV is a complex and demanding process. Extended HMV training and support may be helpful in mediating adjustment challenges thus reducing stress, caregiver burden and improving health related quality of life for VAIs and family caregivers.

Gastropulmonary Route of Infection and the Prevalence of Microaspiration in the Elderly Patients with Ventilator-Associated Pneumonia Verified by Molecular Microbiology-GM-PFGE.

PubMed

Liu, Qing-hua; Zhang, Jing; Lin, Dian-jie; Mou, Xiao-yan; He, Li-xian; Qu, Jie-ming; Li, Hua-yin; Hu, Bi-jie; Zhu, Ying-min; Zhu, Du-ming; Gao, Xiao-dong

2015-04-01

Gastropulmonary route of infection was considered to be an important mechanism of ventilator-associated pneumonia (VAP). However there is little evidence to support this assumption. Moreover, the prevalence of microaspiration in elderly ventilated patients was not well understood. To confirm gastropulmonary infection route and investigate the prevalence of microaspiration in elderly ventilated patients using genome macrorestriction-pulsed field gel electrophoresis (GM-PFGE). Patients over 60 years old, expected to receive mechanical ventilation longer than 48 h, were prospectively enrolled from October 2009 to January 2012. Clinical data were collected and recorded until they died, developed pneumonia, or were extubated. Samples from gastric fluid, subglottic secretion and lower respiratory tract (LRT) were collected during the follow-up for microbiological examination. To evaluate the homogeneity, GM-PFGE was performed on strains responsible for VAP that had the same biochemical phenotype as those isolated from gastric juice and subglottic secretions sequentially. Among 44 VAP patients, 76 strains were isolated from LRT and considered responsible for VAP. Twenty-two isolates had the same biochemical phenotype with the corresponding gastric isolates. The homology was further confirmed using GM-PFGE in 12 episodes of VAP. Nearly 30% of VAPs were caused by microaspiration based on the analysis of bacterial phenotype or GM-PFGE. In addition, 58.3% patients with gastric colonization developed VAP, especially late-onset VAP (LOP). Gastropulmonary infection route exists in VAP especially LOP in elderly ventilated patients. It is one of the important mechanisms in the development of VAP.

The respiratory system during resuscitation: a review of the history, risk of infection during assisted ventilation, respiratory mechanics, and ventilation strategies for patients with an unprotected airway.

PubMed

Wenzel, V; Idris, A H; Dörges, V; Nolan, J P; Parr, M J; Gabrielli, A; Stallinger, A; Lindner, K H; Baskett, P J

2001-05-01

The fear of acquiring infectious diseases has resulted in reluctance among healthcare professionals and the lay public to perform mouth-to-mouth ventilation. However, the benefit of basic life support for a patient in cardiopulmonary or respiratory arrest greatly outweighs the risk for secondary infection in the rescuer or the patient. The distribution of ventilation volume between lungs and stomach in the unprotected airway depends on patient variables such as lower oesophageal sphincter pressure, airway resistance and respiratory system compliance, and the technique applied while performing basic or advanced airway support, such as head position, inflation flow rate and time, which determine upper airway pressure. The combination of these variables determines gas distribution between the lungs and the oesophagus and subsequently, the stomach. During bag-valve-mask ventilation of patients in respiratory or cardiac arrest with oxygen supplementation (> or = 40% oxygen), a tidal volume of 6-7 ml kg(-1) ( approximately 500 ml) given over 1-2 s until the chest rises is recommended. For bag-valve-mask ventilation with room-air, a tidal volume of 10 ml kg(-1) (700-1000 ml) in an adult given over 2 s until the chest rises clearly is recommended. During mouth-to-mouth ventilation, a breath over 2 s sufficient to make the chest rise clearly (a tidal volume of approximately 10 ml kg(-1) approximately 700-1000 ml in an adult) is recommended.

Measurement of lung function using Electrical Impedance Tomography (EIT) during mechanical ventilation

NASA Astrophysics Data System (ADS)

Nebuya, Satoru; Koike, Tomotaka; Imai, Hiroshi; Noshiro, Makoto; Brown, Brian H.; Soma, Kazui

2010-04-01

The consistency of regional lung density measurements as estimated by Electrical Impedance Tomography (EIT), in eleven patients supported by a mechanical ventilator, was validated to verify the feasibility of its use in intensive care medicine. There were significant differences in regional lung densities between the normal lung and diseased lungs associated with pneumonia, atelectasis and pleural effusion (Steel-Dwass test, p < 0.05). Temporal changes in regional lung density of patients with atelectasis were observed to be in good agreement with the results of clinical diagnosis. These results indicate that it is feasible to obtain a quantitative value for regional lung density using EIT.

Acute Right Ventricular Dysfunction in Intensive Care Unit

PubMed Central

Domingo, Enric

2017-01-01

The role of the left ventricle in ICU patients with circulatory shock has long been considered. However, acute right ventricle (RV) dysfunction causes and aggravates many common critical diseases (acute respiratory distress syndrome, pulmonary embolism, acute myocardial infarction, and postoperative cardiac surgery). Several supportive therapies, including mechanical ventilation and fluid management, can make RV dysfunction worse, potentially exacerbating shock. We briefly review the epidemiology, pathophysiology, diagnosis, and recommendations to guide management of acute RV dysfunction in ICU patients. Our aim is to clarify the complex effects of mechanical ventilation, fluid therapy, vasoactive drug infusions, and other therapies to resuscitate the critical patient optimally. PMID:29201914

Comparison between a clinical diagnosis method and the surveillance technique of the Center for Disease Control and Prevention for identification of mechanical ventilator-associated pneumonia.

PubMed

Waltrick, Renata; Possamai, Dimitri Sauter; de Aguiar, Fernanda Perito; Dadam, Micheli; de Souza Filho, Valmir João; Ramos, Lucas Rocker; Laurett, Renata da Silva; Fujiwara, Kênia; Caldeira Filho, Milton; Koenig, Álvaro; Westphal, Glauco Adrieno

2015-01-01

>To evaluate the agreement between a new epidemiological surveillance method of the Center for Disease Control and Prevention and the clinical pulmonary infection score for mechanical ventilator-associated pneumonia detection. This was a prospective cohort study that evaluated patients in the intensive care units of two hospitals who were intubated for more than 48 hours between August 2013 and June 2014. Patients were evaluated daily by physical therapist using the clinical pulmonary infection score. A nurse independently applied the new surveillance method proposed by the Center for Disease Control and Prevention. The diagnostic agreement between the methods was evaluated. A clinical pulmonary infection score of ≥ 7 indicated a clinical diagnosis of mechanical ventilator-associated pneumonia, and the association of a clinical pulmonary infection score ≥ 7 with an isolated semiquantitative culture consisting of ≥ 104 colony-forming units indicated a definitive diagnosis. Of the 801 patients admitted to the intensive care units, 198 required mechanical ventilation. Of these, 168 were intubated for more than 48 hours. A total of 18 (10.7%) cases of mechanical ventilation-associated infectious conditions were identified, 14 (8.3%) of which exhibited possible or probable mechanical ventilator-associated pneumonia, which represented 35% (14/38) of mechanical ventilator-associated pneumonia cases. The Center for Disease Control and Prevention method identified cases of mechanical ventilator-associated pneumonia with a sensitivity of 0.37, specificity of 1.0, positive predictive value of 1.0, and negative predictive value of 0.84. The differences resulted in discrepancies in the mechanical ventilator-associated pneumonia incidence density (CDC, 5.2/1000 days of mechanical ventilation; clinical pulmonary infection score ≥ 7, 13.1/1000 days of mechanical ventilation). The Center for Disease Control and Prevention method failed to detect mechanical ventilator-associated pneumonia cases and may not be satisfactory as a surveillance method.

Treatment of ARDS With Prone Positioning.

PubMed

Scholten, Eric L; Beitler, Jeremy R; Prisk, G Kim; Malhotra, Atul

2017-01-01

Prone positioning was first proposed in the 1970s as a method to improve gas exchange in ARDS. Subsequent observations of dramatic improvement in oxygenation with simple patient rotation motivated the next several decades of research. This work elucidated the physiological mechanisms underlying changes in gas exchange and respiratory mechanics with prone ventilation. However, translating physiological improvements into a clinical benefit has proved challenging; several contemporary trials showed no major clinical benefits with prone positioning. By optimizing patient selection and treatment protocols, the recent Proning Severe ARDS Patients (PROSEVA) trial demonstrated a significant mortality benefit with prone ventilation. This trial, and subsequent meta-analyses, support the role of prone positioning as an effective therapy to reduce mortality in severe ARDS, particularly when applied early with other lung-protective strategies. This review discusses the physiological principles, clinical evidence, and practical application of prone ventilation in ARDS. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Autophagy in pulmonary macrophages mediates lung inflammatory injury via NLRP3 inflammasome activation during mechanical ventilation

PubMed Central

Zhang, Yang; Liu, Gongjian; Dull, Randal O.; Schwartz, David E.

2014-01-01

The inflammatory response is a primary mechanism in the pathogenesis of ventilator-induced lung injury. Autophagy is an essential, homeostatic process by which cells break down their own components. We explored the role of autophagy in the mechanisms of mechanical ventilation-induced lung inflammatory injury. Mice were subjected to low (7 ml/kg) or high (28 ml/kg) tidal volume ventilation for 2 h. Bone marrow-derived macrophages transfected with a scrambled or autophagy-related protein 5 small interfering RNA were administered to alveolar macrophage-depleted mice via a jugular venous cannula 30 min before the start of the ventilation protocol. In some experiments, mice were ventilated in the absence and presence of autophagy inhibitors 3-methyladenine (15 mg/kg ip) or trichostatin A (1 mg/kg ip). Mechanical ventilation with a high tidal volume caused rapid (within minutes) activation of autophagy in the lung. Conventional transmission electron microscopic examination of lung sections showed that mechanical ventilation-induced autophagy activation mainly occurred in lung macrophages. Autophagy activation in the lungs during mechanical ventilation was dramatically attenuated in alveolar macrophage-depleted mice. Selective silencing of autophagy-related protein 5 in lung macrophages abolished mechanical ventilation-induced nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome activation and lung inflammatory injury. Pharmacological inhibition of autophagy also significantly attenuated the inflammatory responses caused by lung hyperinflation. The activation of autophagy in macrophages mediates early lung inflammation during mechanical ventilation via NLRP3 inflammasome signaling. Inhibition of autophagy activation in lung macrophages may therefore provide a novel and promising strategy for the prevention and treatment of ventilator-induced lung injury. PMID:24838752

Duration of Mechanical Ventilation in the Emergency Department.

PubMed

Angotti, Lauren B; Richards, Jeremy B; Fisher, Daniel F; Sankoff, Jeffrey D; Seigel, Todd A; Al Ashry, Haitham S; Wilcox, Susan R

2017-08-01

Due to hospital crowding, mechanically ventilated patients are increasingly spending hours boarding in emergency departments (ED) before intensive care unit (ICU) admission. This study aims to evaluate the association between time ventilated in the ED and in-hospital mortality, duration of mechanical ventilation, ICU and hospital length of stay (LOS). This was a multi-center, prospective, observational study of patients ventilated in the ED, conducted at three academic Level I Trauma Centers from July 2011 to March 2013. All consecutive adult patients on invasive mechanical ventilation were eligible for enrollment. We performed a Cox regression to assess for a mortality effect for mechanically ventilated patients with each hour of increasing LOS in the ED and multivariable regression analyses to assess for independently significant contributors to in-hospital mortality. Our primary outcome was in-hospital mortality, with secondary outcomes of ventilator days, ICU LOS and hospital LOS. We further commented on use of lung protective ventilation and frequency of ventilator changes made in this cohort. We enrolled 535 patients, of whom 525 met all inclusion criteria. Altered mental status without respiratory pathology was the most common reason for intubation, followed by trauma and respiratory failure. Using iterated Cox regression, a mortality effect occurred at ED time of mechanical ventilation > 7 hours, and the longer ED stay was also associated with a longer total duration of intubation. However, adjusted multivariable regression analysis demonstrated only older age and admission to the neurosciences ICU as independently associated with increased mortality. Of interest, only 23.8% of patients ventilated in the ED for over seven hours had changes made to their ventilator. In a prospective observational study of patients mechanically ventilated in the ED, there was a significant mortality benefit to expedited transfer of patients into an appropriate ICU setting.

Successful management of drug-induced hypercapnic acidosis with naloxone and noninvasive positive pressure ventilation.

PubMed

Agrafiotis, Michalis; Tryfon, Stavros; Siopi, Demetra; Chassapidou, Georgia; Galanou, Artemis; Tsara, Venetia

2015-02-01

A 74-year-old man was referred to our hospital due to deteriorating level of consciousness and desaturation. His Glasgow Coma Scale was 6, and his pupils were constricted but responded to light. Chest radiograph was negative for significant findings. Arterial blood gas evaluation on supplemental oxygen revealed severe acute on chronic respiratory acidosis: pH 7.15; PCO2, 133 mm Hg; PO2,64 mm Hg; and HCO3, 31 mmol/L. He regained full consciousness (Glasgow Coma Scale, 15) after receiving a 0.4 mg dose of naloxone, but because of persistent severe respiratory acidosis (pH 7.21; PCO2, 105 mm Hg), he was immediately commenced on noninvasive positive pressure ventilation (NIV) displaying a remarkable improvement in arterial blood gas values within the next few hours. However, in the days that followed, he remained dependent on NIV, and he was finally discharged on a home mechanical ventilation prescription. In cases of drug-induced respiratory depression, NIV should be regarded as an acceptable treatment, as it can provide ventilatory support without the increased risks associated with invasive mechanical ventilation.

Continuous High-Frequency Oscillation Therapy in Invasively Ventilated Pediatric Subjects in the Critical Care Setting.

PubMed

Morgan, Stephen; Hornik, Christoph P; Patel, Niyati; Williford, Walter L; Turner, David A; Cheifetz, Ira M

2016-11-01

Continuous high-frequency oscillation (CHFO) creates a pressure gradient in the small airways that accelerates expiratory flow. The intended use of CHFO therapy is to facilitate secretion removal and treat atelectasis. Our objective was to assess the feasibility, safety, and efficacy of CHFO in the mechanically ventilated pediatric population. After institutional review board approval, we retrospectively reviewed medical records of mechanically ventilated children treated with CHFO (the MetaNeb system) at our institution from July 1, 2007 through August 31, 2012. Patients supported with extracorporeal membrane oxygenation were excluded. We evaluated changes in ventilator settings in subjects with ventilator data documented within 6 h pre- and post-treatment. We evaluated arterial blood gas (ABG) results for individual treatments, comparing ABG results within 8 h pre-therapy to ABG results within 3 h post-treatment. Oxygen index and P aO 2 /F IO 2 were calculated. Demographic data, blood pressure, heart rate, and development of new air leak while being treated with CHFO were recorded. Pre- and post-CHFO measurements were compared using Wilcoxon signed-rank testing. Our cohort included 59 invasively ventilated subjects. Median age was 2 y (range 1 month to 19 y), and median weight was 14 kg (2-81 kg). We evaluated data on 528 total treatments (range per subject 1-39 treatments). Peak inspiratory pressure significantly decreased with CHFO, whereas other parameters, including P aCO 2 and breathing frequency, remained stable. There was no significant change in systolic blood pressure, diastolic blood pressure, or heart rate following treatment with CHFO. One subject (2%) developed a clinically insignificant pneumothorax during CHFO. CHFO is feasible and seems safe in our cohort of mechanically ventilated pediatric subjects. The rate of pneumothorax was consistent with that seen in similar pediatric ICU populations. These preliminary results suggest that CHFO may be beneficial by improving lung compliance in pediatric subjects with secretion-induced atelectasis. Prospective clinical studies are needed to further evaluate the clinical efficacy and safety of CHFO in children receiving invasive mechanical ventilation. Copyright © 2016 by Daedalus Enterprises.

Trends in mechanical ventilation: are we ventilating our patients in the best possible way?

PubMed

Dellaca', Raffaele L; Veneroni, Chiara; Farre', Ramon

2017-06-01

This review addresses how the combination of physiology, medicine and engineering principles contributed to the development and advancement of mechanical ventilation, emphasising the most urgent needs for improvement and the most promising directions of future development. Several aspects of mechanical ventilation are introduced, highlighting on one side the importance of interdisciplinary research for further development and, on the other, the importance of training physicians sufficiently on the technological aspects of modern devices to exploit properly the great complexity and potentials of this treatment. To learn how mechanical ventilation developed in recent decades and to provide a better understanding of the actual technology and practice.To learn how and why interdisciplinary research and competences are necessary for providing the best ventilation treatment to patients.To understand which are the most relevant technical limitations in modern mechanical ventilators that can affect their performance in delivery of the treatment.To better understand and classify ventilation modes.To learn the classification, benefits, drawbacks and future perspectives of automatic ventilation tailoring algorithms.

Protective mechanical ventilation does not exacerbate lung function impairment or lung inflammation following influenza A infection.

PubMed

Zosky, Graeme R; Cannizzaro, Vincenzo; Hantos, Zoltan; Sly, Peter D

2009-11-01

The degree to which mechanical ventilation induces ventilator-associated lung injury is dependent on the initial acute lung injury (ALI). Viral-induced ALI is poorly studied, and this study aimed to determine whether ALI induced by a clinically relevant infection is exacerbated by protective mechanical ventilation. Adult female BALB/c mice were inoculated with 10(4.5) plaque-forming units of influenza A/Mem/1/71 in 50 microl of medium or medium alone. This study used a protective ventilation strategy, whereby mice were anesthetized, tracheostomized, and mechanically ventilated for 2 h. Lung mechanics were measured periodically throughout the ventilation period using a modification of the forced oscillation technique to obtain measures of airway resistance and coefficients of tissue damping and tissue elastance. Thoracic gas volume was measured and used to obtain specific airway resistance, tissue damping, and tissue elastance. At the end of the ventilation period, a bronchoalveolar lavage sample was collected to measure inflammatory cells, macrophage inflammatory protein-2, IL-6, TNF-alpha, and protein leak. Influenza infection caused significant increases in inflammatory cells, protein leak, and deterioration in lung mechanics that were not exacerbated by mechanical ventilation, in contrast to previous studies using bacterial and mouse-specific viral infection. This study highlighted the importance of type and severity of lung injury in determining outcome following mechanical ventilation.

Controlled invasive mechanical ventilation strategies in obese patients undergoing surgery.

PubMed

Maia, Lígia de Albuquerque; Silva, Pedro Leme; Pelosi, Paolo; Rocco, Patricia Rieken Macedo

2017-06-01

The obesity prevalence is increasing in surgical population. As the number of obese surgical patients increases, so does the demand for mechanical ventilation. Nevertheless, ventilatory strategies in this population are challenging, since obesity results in pathophysiological changes in respiratory function. Areas covered: We reviewed the impact of obesity on respiratory system and the effects of controlled invasive mechanical ventilation strategies in obese patients undergoing surgery. To date, there is no consensus regarding the optimal invasive mechanical ventilation strategy for obese surgical patients, and no evidence that possible intraoperative beneficial effects on oxygenation and mechanics translate into better postoperative pulmonary function or improved outcomes. Expert commentary: Before determining the ideal intraoperative ventilation strategy, it is important to analyze the pathophysiology and comorbidities of each obese patient. Protective ventilation with low tidal volume, driving pressure, energy, and mechanical power should be employed during surgery; however, further studies are required to clarify the most effective ventilation strategies, such as the optimal positive end-expiratory pressure and whether recruitment maneuvers minimize lung injury. In this context, an ongoing trial of intraoperative ventilation in obese patients (PROBESE) should help determine the mechanical ventilation strategy that best improves clinical outcome in patients with body mass index≥35kg/m 2 .

Development and application of a double-piston configured, total-liquid ventilatory support device.

PubMed

Meinhardt, J P; Quintel, M; Hirschl, R B

2000-05-01

Perfluorocarbon liquid ventilation has been shown to enhance pulmonary mechanics and gas exchange in the setting of respiratory failure. To optimize the total liquid ventilation process, we developed a volume-limited, time-cycled liquid ventilatory support, consisting of an electrically actuated, microprocessor-controlled, double-cylinder, piston pump with two separate limbs for active inspiration and expiration. Prospective, controlled, animal laboratory study, involving sequential application of conventional gas ventilation, partial ventilation (PLV), and total liquid ventilation (TLV). Research facility at a university medical center. A total of 12 normal adult New Zealand rabbits weighing 3.25+/-0.1 kg. Anesthestized rabbits were supported with gas ventilation for 30 mins (respiratory rate, 20 cycles/min; peak inspiratory pressure, 15 cm H2O; end-expiratory pressure, 5 cm H2O), then PLV was established with perflubron (12 mL/kg). After 15 mins, TLV was instituted (tidal volume, 18 mL/kg; respiratory rate, 7 cycles/min; inspiratory/expiratory ratio, 1:2 cycles/min). After 4 hrs of TLV, PLV was re-established. Of 12 animals, nine survived the 4-hr TLV period. During TLV, mean values +/- SEM were as follows: PaO2, 363+/-30 torr; PaCO2, 39+/-1.5 torr; pH, 7.39+/-0.01; static peak inspiratory pressure, 13.2+/-0.2 cm H2O; static endexpiratory pressure, 5.5+/-0.1 cm H2O. No significant changes were observed. When compared with gas ventilation and PLV, significant increases occurred in mean arterial pressure (62.4+/-3.5 torr vs. 74.0+/-1.2 torr) and central venous pressure (5.6+/-0.7 cm H2O vs. 7.8+/-0.2 cm H2O) (p < .05). Total liquid ventilation can be performed successfully utilizing piston pumps with active expiration. Considering the enhanced flow profiles, this device configuration provides advantages over others.

Mechanical ventilation and thoracic artificial lung assistance during mechanical circulatory support with PUCA pump: in silico study.

PubMed

De Lazzari, Claudio; Genuini, Igino; Quatember, Bernhard; Fedele, Francesco

2014-02-01

Patients assisted with left ventricular assist device (LVAD) may require prolonged mechanical ventilatory assistance secondary to postoperative respiratory failure. The goal of this work is the study of the interdependent effects LVAD like pulsatile catheter (PUCA) pump and mechanical ventilatory support or thoracic artificial lung (TAL), by the hemodynamic point of view, using a numerical simulator of the human cardiovascular system. In the simulator, different circulatory sections are described using lumped parameter models. Lumped parameter models have been designed to describe the hydrodynamic behavior of both PUCA pump and thoracic artificial lung. Ventricular behavior atrial and septum functions were reproduced using variable elastance model. Starting from simulated pathological conditions we studied the effects produced on some hemodynamic variables by simultaneous PUCA pump, thoracic artificial lung or mechanical ventilation assistance. Thoracic artificial lung was applied in parallel or in hybrid mode. The effects of mechanical ventilation have been simulated by changing mean intrathoracic pressure value from -4 mmHg to +5 mmHg. The hemodynamic variables observed during the simulations, in different assisted conditions, were: left and right ventricular end systolic (diastolic) volume, systolic/diastolic aortic pressure, mean pulmonary arterial pressure, left and right mean atrial pressure, mean systemic venous pressure and the total blood flow. Results show that the application of PUCA (without mechanical ventilatory assistance) increases the total blood flow, reduces the left ventricular end systolic volume and increases the diastolic aortic pressure. Parallel TAL assistance increases the right ventricular end diastolic (systolic) volume reduction both when PUCA is switched "ON" and both when PUCA is switched "OFF". By switching "OFF" the PUCA pump, it seems that parallel thoracic artificial lung assistance produces a greater cardiac output (respect to hybrid TAL assistance). Results concerning PUCA and TAL interaction produced by simulations cannot be compared with "in vivo" results since they are not presented in literature. But results concerning the effects produced by LVAD and mechanical ventilation have a trend consistent with those presented in literature. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Adaptive support ventilation may deliver unwanted respiratory rate-tidal volume combinations in patients with acute lung injury ventilated according to an open lung concept.

PubMed

Dongelmans, Dave A; Paulus, Frederique; Veelo, Denise P; Binnekade, Jan M; Vroom, Margreeth B; Schultz, Marcus J

2011-05-01

With adaptive support ventilation, respiratory rate and tidal volume (V(T)) are a function of the Otis least work of breathing formula. We hypothesized that adaptive support ventilation in an open lung ventilator strategy would deliver higher V(T)s to patients with acute lung injury. Patients with acute lung injury were ventilated according to a local guideline advising the use of lower V(T) (6-8 ml/kg predicted body weight), high concentrations of positive end-expiratory pressure, and recruitment maneuvers. Ventilation parameters were recorded when the ventilator was switched to adaptive support ventilation, and after recruitment maneuvers. If V(T) increased more than 8 ml/kg predicted body weight, airway pressure was limited to correct for the rise of V(T). Ten patients with a mean (±SD) Pao(2)/Fio(2) of 171 ± 86 mmHg were included. After a switch from pressure-controlled ventilation to adaptive support ventilation, respiratory rate declined (from 31 ± 5 to 21 ± 6 breaths/min; difference = 10 breaths/min, 95% CI 3-17 breaths/min, P = 0.008) and V(T) increased (from 6.5 ± 0.8 to 9.0 ± 1.6 ml/kg predicted body weight; difference = 2.5 ml, 95% CI 0.4-4.6 ml/kg predicted body weight, P = 0.02). Pressure limitation corrected for the rise of V(T), but minute ventilation declined, forcing the user to switch back to pressure-controlled ventilation. Adaptive support ventilation, compared with pressure-controlled ventilation in an open lung strategy setting, delivers a lower respiratory rate-higher V(T) combination. Pressure limitation does correct for the rise of V(T), but leads to a decline in minute ventilation.

Hydrotherapy for the long-term ventilated patient: A case study and implications for practice.

PubMed

Wegner, Sally; Thomas, Peter; James, Christine

2017-11-01

Hydrotherapy of mechanically ventilated patients has been shown to be safe and feasible in both the acute stages of critical illness and in those requiring long term mechanical ventilation. This case study describes the hydrotherapy sessions of a 36 year old female, who after suffering complications of pneumococcal meningitis, became an incomplete quadriplegic and required long term mechanical ventilation. When implementing hydrotherapy with patients on mechanical ventilation a number of factors should be considered. These include staff resources and training, airway and ventilation management, patient preparation and safety procedures. Hydrotherapy can be safely utilised with mechanically ventilated patients, and may facilitate a patient's ability to participate in active exercise and rehabilitation. Copyright © 2017 Australian College of Critical Care Nurses Ltd. All rights reserved.

Noise measurements during high-frequency oscillatory and conventional mechanical ventilation.

PubMed

Berens, R J; Weigle, C G

1995-10-01

To evaluate the noise levels with high-frequency oscillatory ventilation and conventional mechanical ventilation. An observational, prospective study. Pediatric intensive care unit. The caretakers and environment of the pediatric intensive care unit. High-frequency oscillatory and conventional mechanical ventilation. Caretakers evaluated noise using a visual analog scale. Noise was measured with a decibel meter and an octave band frequency filter. There was twice as much noise perceived by the caretakers and as measured on the decibel A scale. All measures showed significantly greater noise, especially at low frequencies, with high-frequency oscillatory ventilation. High-frequency oscillatory ventilation exposes the patient to twice as much noise as does the use of conventional mechanical ventilation.

Ventilation in the patient with unilateral lung disease.

PubMed

Thomas, A R; Bryce, T L

1998-10-01

Severe ULD presents a challenge in ventilator management because of the marked asymmetry in the mechanics of the two lungs. The asymmetry may result from significant decreases or increases in the compliance of the involved lung. Traditional ventilator support may fail to produce adequate gas exchange in these situations and has the potential to cause further deterioration. Fortunately, conventional techniques can be safely and effectively applied in the majority of cases without having to resort to less familiar and potentially hazardous forms of support. In those circumstances when conventional ventilation is unsuccessful in restoring adequate gas exchange, lateral positioning and ILV have proved effective at improving and maintaining gas exchange. Controlled trials to guide clinical decision making are lacking. In patients who have processes associated with decreased compliance in the involved lung, lateral positioning may be a simple method of improving gas exchange but is associated with many practical limitations. ILV in these patients is frequently successful when differential PEEP is applied with the higher pressure to the involved lung. In patients in whom the pathology results in distribution of ventilation favoring the involved lung, particularly BPF, ILV can be used to supply adequate support while minimizing flow through the fistula and allowing it to close. The application of these techniques should be undertaken with an understanding of the pathophysiology of the underlying process; the reported experience with these techniques, including indications and successfully applied methods; and the potential problems encountered with their use. Fortunately, these modalities are infrequently required, but they provide a critical means of support when conventional techniques fail.

Effects of types of ventilation system on indoor particle concentrations in residential buildings.

PubMed

Park, J S; Jee, N-Y; Jeong, J-W

2014-12-01

The objective of this study was to quantify the influence of ventilation systems on indoor particle concentrations in residential buildings. Fifteen occupied, single-family apartments were selected from three sites. The three sites have three different ventilation systems: unbalanced mechanical ventilation, balanced mechanical ventilation, and natural ventilation. Field measurements were conducted between April and June 2012, when outdoor air temperatures were comfortable. Number concentrations of particles, PM2.5 and CO2 , were continuously measured both outdoors and indoors. In the apartments with natural ventilation, I/O ratios of particle number concentrations ranged from 0.56 to 0.72 for submicron particles, and from 0.25 to 0.60 for particles larger than 1.0 μm. The daily average indoor particle concentration decreased to 50% below the outdoor level for submicron particles and 25% below the outdoor level for fine particles, when the apartments were mechanically ventilated. The two mechanical ventilation systems reduced the I/O ratios by 26% for submicron particles and 65% for fine particles compared with the natural ventilation. These results showed that mechanical ventilation can reduce exposure to outdoor particles in residential buildings. Results of this study confirm that mechanical ventilation with filtration can significantly reduce indoor particle levels compared with natural ventilation. The I/O ratios of particles substantially varied at the naturally ventilated apartments because of the influence of variable window opening conditions and unsteadiness of wind flow on the penetration of outdoor air particles. For better prediction of the exposure to outdoor particles in naturally ventilated residential buildings, it is important to understand the penetration of outdoor particles with variable window opening conditions. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Nasal high-flow therapy reduces work of breathing compared with oxygen during sleep in COPD and smoking controls: a prospective observational study

PubMed Central

Kirkness, Jason P.; Grote, Ludger; Fricke, Kathrin; Schwartz, Alan R.; Smith, Philip; Schneider, Hartmut

2017-01-01

Patients with chronic obstructive pulmonary disease (COPD) endure excessive resistive and elastic loads leading to chronic respiratory failure. Oxygen supplementation corrects hypoxemia but is not expected to reduce mechanical loads. Nasal high-flow (NHF) therapy supports breathing by reducing dead space, but it is unclear how it affects mechanical loads of patients with COPD. The objective of this study was to compare the effects of low-flow oxygen and NHF therapy on ventilation and work of breathing (WOB) in patients with COPD and controls during sleep. Patients with COPD (n = 12) and controls (n = 6) were recruited and submitted to polysomnography to measure sleep parameters and ventilation in response to administration of oxygen and NHF. A subset of six patients also had an esophageal catheter inserted for the purpose of measuring WOB. Patients with COPD had similar minute ventilation (V̇e) but lower tidal volumes than matched controls. With oxygen, SaO2was increased and V̇e was reduced in both controls and patients with COPD, but there was an increase in transcutaneous CO2 levels. NHF produced a greater reduction in V̇e and was associated with a reduction in CO2 levels. Although NHF halved WOB, oxygen produced only a minor reduction in this parameter. We conclude that oxygen produced little change in WOB, which was associated with CO2 elevations. On the other hand, NHF produced a large reduction in V̇e and WOB with a concomitant decrease in CO2 levels. Our data indicate that NHF improves alveolar ventilation during sleep compared with oxygen and room air in patients with COPD and therefore can decrease their cost of breathing. NEW & NOTEWORTHY Nasal high-flow (NHF) therapy can support ventilation in patients with chronic obstructive pulmonary disease during sleep by decreasing the work of breathing and improving CO2 levels. On the other hand, oxygen supplementation corrects hypoxemia, but it produces only a minimal reduction in work of breathing and is associated with increased CO2 levels. Therefore, NHF can be a useful method to assist ventilation in patients with increased respiratory mechanical loads. PMID:27815367

Combination of Extracorporeal Life Support and Mesenchymal Stem Cell Therapy for Treatment of ARDS in Combat Casualties and Evacuation of Service Members with ARDS

DTIC Science & Technology

2017-10-01

invasiveness of mechanical ventilation and inflammatory mediators as well as improvement in oxygenation and functional outcome. 4 Keywords Acute...The Clark system is allowing us to measure the mitochondrial activity by the oxygen consumption during activation. Because the LPS-induced injury we... Ventilation • Tidal Volume • Respiratory Rate • Peak inspiratory Pressure • Positive End Expiratory Pressure (PEEP) • Fraction of inspired oxygen

Communicating with individuals receiving home mechanical ventilation: the experiences of key communication partners.

PubMed

Laakso, Katja; Markström, Agneta; Havstam, Christina; Idvall, Markus; Hartelius, Lena

2014-01-01

The aim of the study was to explore the communication experiences of key communications partners (CPs) of individuals receiving home mechanical ventilation (HMV), with particular emphasis on the possibilities, difficulties and limitations CPs experienced in communication, possible support given to facilitate communication and exploring what made a skilled communicator. A qualitative research design using interviews was used. The participants included 19 key CPs of individuals receiving HMV. The analysis resulted in five themes: Encountering communication limitations, Functional communication strategies, Being a communication facilitator, Role insecurity and Emotional reactions and coping. The findings revealed that CPs needed to develop partly new reference frames for communication. In particular, participants emphasised the need to understand and interpret subtle details in the communicative interaction. The findings are discussed in the light of previous research, in particular an earlier study exploring another perspective; the ventilator-supported individuals' experiences of communication. Issues relating to the educational needs of CPs of individuals receiving HMV are discussed. The results are intended to enhance understanding of the challenges that individuals receiving HMV and their CPs face with communication, which should be of relevance not only to speech therapists, but for all healthcare practitioners in the field of HMV.

Management and outcome of mechanically ventilated neurologic patients.

PubMed

Pelosi, Paolo; Ferguson, Niall D; Frutos-Vivar, Fernando; Anzueto, Antonio; Putensen, Christian; Raymondos, Konstantinos; Apezteguia, Carlos; Desmery, Pablo; Hurtado, Javier; Abroug, Fekri; Elizalde, José; Tomicic, Vinko; Cakar, Nahit; Gonzalez, Marco; Arabi, Yaseen; Moreno, Rui; Esteban, Andres

2011-06-01

To describe and compare characteristics, ventilatory practices, and associated outcomes among mechanically ventilated patients with different types of brain injury and between neurologic and nonneurologic patients. Secondary analysis of a prospective, observational, and multicenter study on mechanical ventilation. Three hundred forty-nine intensive care units from 23 countries. We included 552 mechanically ventilated neurologic patients (362 patients with stroke and 190 patients with brain trauma). For comparison we used a control group of 4,030 mixed patients who were ventilated for nonneurologic reasons. None. We collected demographics, ventilatory settings, organ failures, and complications arising during ventilation and outcomes. Multivariate logistic regression analysis was performed with intensive care unit mortality as the dependent variable. At admission, a Glasgow Coma Scale score ≤8 was observed in 68% of the stroke, 77% of the brain trauma, and 29% of the nonneurologic patients. Modes of ventilation and use of a lung-protective strategy within the first week of mechanical ventilation were similar between groups. In comparison with nonneurologic patients, patients with neurologic disease developed fewer complications over the course of mechanical ventilation with the exception of a higher rate of ventilator-associated pneumonia in the brain trauma cohort. Neurologic patients showed higher rates of tracheotomy and longer duration of mechanical ventilation. Mortality in the intensive care unit was significantly (p < .001) higher in patients with stroke (45%) than in brain trauma (29%) and nonneurologic disease (30%). Factors associated with mortality were: stroke (in comparison to brain trauma), Glasgow Coma Scale score on day 1, and severity at admission in the intensive care unit. In our study, one of every five mechanically ventilated patients received this therapy as a result of a neurologic disease. This cohort of patients showed a higher mortality rate than nonneurologic patients despite a lower incidence of extracerebral organ dysfunction.

Analysis of a Pediatric Home Mechanical Ventilator Population.

PubMed

Amirnovin, Rambod; Aghamohammadi, Sara; Riley, Carley; Woo, Marlyn S; Del Castillo, Sylvia

2018-05-01

The population of children requiring home mechanical ventilation has evolved over the years and has grown to include a variety of diagnoses and needs that have led to changes in the care of this unique population. The purpose of this study was to provide a descriptive analysis of pediatric patients requiring home mechanical ventilation after hospitalization and how the evolution of this technology has impacted their care. A retrospective, observational, longitudinal analysis of 164 children enrolled in a university-affiliated home mechanical ventilation program over 26 years was performed. Data included each child's primary diagnosis, date of tracheostomy placement, duration of mechanical ventilation during hospitalization that consisted of home mechanical ventilator initiation, total length of pediatric ICU stay, ventilator settings at time of discharge from pediatric ICU, and disposition (home, facility, or died). Univariate, bivariate, and regression analysis was used as appropriate. The most common diagnosis requiring the use of home mechanical ventilation was neuromuscular disease (53%), followed by chronic pulmonary disease (29%). The median length of stay in the pediatric ICU decreased significantly after the implementation of a ventilator ward (70 d [30-142] vs 36 d [18-67], P = .02). The distribution of subjects upon discharge was home (71%), skilled nursing facility (24%), and died (4%), with an increase in the proportion of subjects discharged on PEEP and those going to nursing facilities over time ( P = 0.02). The evolution of home mechanical ventilation has allowed earlier transition out of the pediatric ICU and with increasing disposition to skilled nursing facilities over time. There has also been a change in ventilator management, including increased use of PEEP upon discharge, possibly driven by changes in ventilators and in-patient practice patterns. Copyright © 2018 by Daedalus Enterprises.

Initial mechanical ventilator settings and lung protective ventilation in the ED.

PubMed

Wilcox, Susan R; Richards, Jeremy B; Fisher, Daniel F; Sankoff, Jeffrey; Seigel, Todd A

2016-08-01

Mechanical ventilation with low tidal volumes has been shown to improve outcomes for patients both with and without acute respiratory distress syndrome. This study aims to characterize mechanically ventilated patients in the emergency department (ED), describe the initial ED ventilator settings, and assess for associations between lung protective ventilation strategies in the ED and outcomes. This was a multicenter, prospective, observational study of mechanical ventilation at 3 academic EDs. We defined lung protective ventilation as a tidal volume of less than or equal to 8 mL/kg of predicted body weight and compared outcomes for patients ventilated with lung protective vs non-lung protective ventilation, including inhospital mortality, ventilator days, intensive care unit length of stay, and hospital length of stay. Data from 433 patients were analyzed. Altered mental status without respiratory pathology was the most common reason for intubation, followed by trauma and respiratory failure. Two hundred sixty-one patients (60.3%) received lung protective ventilation, but most patients were ventilated with a low positive end-expiratory pressure, high fraction of inspired oxygen strategy. Patients were ventilated in the ED for a mean of 5 hours and 7 minutes but had few ventilator adjustments. Outcomes were not significantly different between patients receiving lung protective vs non-lung protective ventilation. Nearly 40% of ED patients were ventilated with non-lung protective ventilation as well as with low positive end-expiratory pressure and high fraction of inspired oxygen. Despite a mean ED ventilation time of more than 5 hours, few patients had adjustments made to their ventilators. Copyright © 2016 Elsevier Inc. All rights reserved.

Invasive Mechanical Ventilation and Mortality in Pediatric Hematopoietic Stem Cell Transplantation: A Multicenter Study.

PubMed

Rowan, Courtney M; Gertz, Shira J; McArthur, Jennifer; Fitzgerald, Julie C; Nitu, Mara E; Loomis, Ashley; Hsing, Deyin D; Duncan, Christine N; Mahadeo, Kris M; Smith, Lincoln S; Moffet, Jerelyn; Hall, Mark W; Pinos, Emily L; Cheifetz, Ira M; Tamburro, Robert F

2016-04-01

To establish the current respiratory practice patterns in pediatric hematopoietic stem cell transplant patients and investigate their associations with mortality across multiple centers. Retrospective cohort between 2009 and 2014. Twelve children's hospitals in the United States. Two hundred twenty-two pediatric allogeneic hematopoietic stem cell transplant recipients with acute respiratory failure using invasive mechanical ventilation. None. PICU mortality of our cohort was 60.4%. Mortality at 180 days post PICU discharge was 74%. Length of PICU stay prior to initiation of invasive mechanical ventilation was significantly lower in survivors, and the odds of mortality increased for longer length of PICU stay prior to intubation. A total of 91 patients (41%) received noninvasive ventilation at some point during their PICU stay prior to intubation. Noninvasive ventilation use preintubation was associated with increased mortality (odds ratio, 2.1; 95% CI, 1.2-3.6; p = 0.010). Patients ventilated longer than 15 days had higher odds of death (odds ratio, 2.4; 95% CI, 1.3-4.2; p = 0.004). Almost 40% of patients (n = 85) were placed on high-frequency oscillatory ventilation with a mortality of 76.5% (odds ratio, 3.3; 95% CI, 1.7-6.5; p = 0.0004). Of the 20 patients who survived high-frequency oscillatory ventilation, 18 were placed on high-frequency oscillatory ventilation no later than the third day of invasive mechanical ventilation. In this subset of 85 patients, transition to high-frequency oscillatory ventilation within 2 days of the start of invasive mechanical ventilation resulted in a 76% decrease in the odds of death compared with those who transitioned to high-frequency oscillatory ventilation later in the invasive mechanical ventilation course. This study suggests that perhaps earlier more aggressive critical care interventions in the pediatric hematopoietic stem cell transplant patient with respiratory failure requiring invasive mechanical ventilation may offer an opportunity to improve outcomes.

Ethical challenges in home mechanical ventilation: a secondary analysis.

PubMed

Dybwik, Knut; Nielsen, Erik Waage; Brinchmann, Berit Støre

2012-03-01

The aim of this study was to explore the ethical challenges in home mechanical ventilation based on a secondary analysis of qualitative empirical data. The data included perceptions of healthcare professionals in hospitals and community health services and family members of children and adults using home mechanical ventilation. The findings show that a number of ethical challenges, or dilemmas, arise at all levels in the course of treatment: deciding who should be offered home mechanical ventilation, respect for patient and family wishes, quality of life, dignity and equal access to home mechanical ventilation. Other challenges were the impacts home mechanical ventilation had on the patient, the family, the healthcare services and the allocation of resources. A better and broader understanding of these issues is crucial in order to improve the quality of care for both patient and family and assist healthcare professionals involved in home mechanical ventilation to make decisions for the good of the patient and his or her family.

Are specialized endotracheal tubes and heat-and-moisture exchangers cost-effective in preventing ventilator associated pneumonia?

PubMed

Gentile, Michael A; Siobal, Mark S

2010-02-01

Ventilator-associated pneumonia (VAP) is a common and serious complication of mechanical ventilation via an artificial airway. As with all nosocomial infections, VAP increases costs, morbidity, and mortality in the intensive care unit (ICU). VAP prevention is a multifaceted priority of the intensive care team, and can include the use of specialized artificial airways and heat-and-moisture exchangers (HME). Substantial evidence supports the use of endotracheal tubes (ETTs) that allow subglottic suctioning; silver-coated and antiseptic-impregnated ETTs; ETTs with thin-walled polyurethane cuffs; and HMEs, but these devices also can have adverse effects. Controversy still exists regarding the evidence, cost-effectiveness, and disadvantages and risks of these devices.

Randomized controlled trial comparing nasal intermittent positive pressure ventilation and nasal continuous positive airway pressure in premature infants after tracheal extubation.

PubMed

Komatsu, Daniela Franco Rizzo; Diniz, Edna Maria de Albuquerque; Ferraro, Alexandre Archanjo; Ceccon, Maria Esther Jurvest Rivero; Vaz, Flávio Adolfo Costa

2016-09-01

To analyze the frequency of extubation failure in premature infants using conventional mechanical ventilation (MV) after extubation in groups subjected to nasal intermittent positive pressure ventilation (nIPPV) and continuous positive airway pressure (nCPAP). Seventy-two premature infants with respiratory failure were studied, with a gestational age (GA) ≤ 36 weeks and birth weight (BW) > 750 g, who required tracheal intubation and mechanical ventilation. The study was controlled and randomized in order to ensure that the members of the groups used in the research were chosen at random. Randomization was performed at the time of extubation using sealed envelopes. Extubation failure was defined as the need for re-intubation and mechanical ventilation during the first 72 hours after extubation. Among the 36 premature infants randomized to nIPPV, six (16.6%) presented extubation failure in comparison to 11 (30.5%) of the 36 premature infants randomized to nCPAP. There was no statistical difference between the two study groups regarding BW, GA, classification of the premature infant, and MV time. The main cause of extubation failure was the occurrence of apnea. Gastrointestinal and neurological complications did not occur in the premature infants participating in the study. We found that, despite the extubation failure of the group of premature infants submitted to nIPPV being numerically smaller than in premature infants submitted to nCPAP, there was no statistically significant difference between the two modes of ventilatory support after extubation.

Mechanical ventilator - infants

MedlinePlus

... this page: //medlineplus.gov/ency/article/007240.htm Mechanical ventilator - infants To use the sharing features on this page, please enable JavaScript. A mechanical ventilator is a machine that assists with breathing. ...

Mechanical ventilation with lower tidal volumes and positive end-expiratory pressure prevents pulmonary inflammation in patients without preexisting lung injury.

PubMed

Wolthuis, Esther K; Choi, Goda; Dessing, Mark C; Bresser, Paul; Lutter, Rene; Dzoljic, Misa; van der Poll, Tom; Vroom, Margreeth B; Hollmann, Markus; Schultz, Marcus J

2008-01-01

Mechanical ventilation with high tidal volumes aggravates lung injury in patients with acute lung injury or acute respiratory distress syndrome. The authors sought to determine the effects of short-term mechanical ventilation on local inflammatory responses in patients without preexisting lung injury. Patients scheduled to undergo an elective surgical procedure (lasting > or = 5 h) were randomly assigned to mechanical ventilation with either higher tidal volumes of 12 ml/kg ideal body weight and no positive end-expiratory pressure (PEEP) or lower tidal volumes of 6 ml/kg and 10 cm H2O PEEP. After induction of anesthesia and 5 h thereafter, bronchoalveolar lavage fluid and/or blood was investigated for polymorphonuclear cell influx, changes in levels of inflammatory markers, and nucleosomes. Mechanical ventilation with lower tidal volumes and PEEP (n = 21) attenuated the increase of pulmonary levels of interleukin (IL)-8, myeloperoxidase, and elastase as seen with higher tidal volumes and no PEEP (n = 19). Only for myeloperoxidase, a difference was found between the two ventilation strategies after 5 h of mechanical ventilation (P < 0.01). Levels of tumor necrosis factor alpha, IL-1alpha, IL-1beta, IL-6, macrophage inflammatory protein 1alpha, and macrophage inflammatory protein 1beta in the bronchoalveolar lavage fluid were not affected by mechanical ventilation. Plasma levels of IL-6 and IL-8 increased with mechanical ventilation, but there were no differences between the two ventilation groups. The use of lower tidal volumes and PEEP may limit pulmonary inflammation in mechanically ventilated patients without preexisting lung injury. The specific contribution of both lower tidal volumes and PEEP on the protective effects of the lung should be further investigated.

Ventilation distribution measured with EIT at varying levels of pressure support and Neurally Adjusted Ventilatory Assist in patients with ALI.

PubMed

Blankman, Paul; Hasan, Djo; van Mourik, Martijn S; Gommers, Diederik

2013-06-01

The purpose of this study was to compare the effect of varying levels of assist during pressure support (PSV) and Neurally Adjusted Ventilatory Assist (NAVA) on the aeration of the dependent and non-dependent lung regions by means of Electrical Impedance Tomography (EIT). We studied ten mechanically ventilated patients with Acute Lung Injury (ALI). Positive-End Expiratory Pressure (PEEP) and PSV levels were both 10 cm H₂O during the initial PSV step. Thereafter, we changed the inspiratory pressure to 15 and 5 cm H₂O during PSV. The electrical activity of the diaphragm (EAdi) during pressure support ten was used to define the initial NAVA gain (100 %). Thereafter, we changed NAVA gain to 150 and 50 %, respectively. After each step the assist level was switched back to PSV 10 cm H₂O or NAVA 100 % to get a new baseline. The EIT registration was performed continuously. Tidal impedance variation significantly decreased during descending PSV levels within patients, whereas not during NAVA. The dorsal-to-ventral impedance distribution, expressed according to the center of gravity index, was lower during PSV compared to NAVA. Ventilation contribution of the dependent lung region was equally in balance with the non-dependent lung region during PSV 5 cm H₂O, NAVA 50 and 100 %. Neurally Adjusted Ventilatory Assist ventilation had a beneficial effect on the ventilation of the dependent lung region and showed less over-assistance compared to PSV in patients with ALI.

Atlantic-Pacific Asymmetry in Deep Water Formation

NASA Astrophysics Data System (ADS)

Ferreira, David; Cessi, Paola; Coxall, Helen K.; de Boer, Agatha; Dijkstra, Henk A.; Drijfhout, Sybren S.; Eldevik, Tor; Harnik, Nili; McManus, Jerry F.; Marshall, David P.; Nilsson, Johan; Roquet, Fabien; Schneider, Tapio; Wills, Robert C.

2018-05-01

While the Atlantic Ocean is ventilated by high-latitude deep water formation and exhibits a pole-to-pole overturning circulation, the Pacific Ocean does not. This asymmetric global overturning pattern has persisted for the past 2–3 million years, with evidence for different ventilation modes in the deeper past. In the current climate, the Atlantic-Pacific asymmetry occurs because the Atlantic is more saline, enabling deep convection. To what extent the salinity contrast between the two basins is dominated by atmospheric processes (larger net evaporation over the Atlantic) or oceanic processes (salinity transport into the Atlantic) remains an outstanding question. Numerical simulations have provided support for both mechanisms; observations of the present climate support a strong role for atmospheric processes as well as some modulation by oceanic processes. A major avenue for future work is the quantification of the various processes at play to identify which mechanisms are primary in different climate states.

Rationale and study design of PROVHILO - a worldwide multicenter randomized controlled trial on protective ventilation during general anesthesia for open abdominal surgery.

PubMed

Hemmes, Sabrine N T; Severgnini, Paolo; Jaber, Samir; Canet, Jaume; Wrigge, Hermann; Hiesmayr, Michael; Tschernko, Edda M; Hollmann, Markus W; Binnekade, Jan M; Hedenstierna, Göran; Putensen, Christian; de Abreu, Marcelo Gama; Pelosi, Paolo; Schultz, Marcus J

2011-05-06

Post-operative pulmonary complications add to the morbidity and mortality of surgical patients, in particular after general anesthesia >2 hours for abdominal surgery. Whether a protective mechanical ventilation strategy with higher levels of positive end-expiratory pressure (PEEP) and repeated recruitment maneuvers; the "open lung strategy", protects against post-operative pulmonary complications is uncertain. The present study aims at comparing a protective mechanical ventilation strategy with a conventional mechanical ventilation strategy during general anesthesia for abdominal non-laparoscopic surgery. The PROtective Ventilation using HIgh versus LOw positive end-expiratory pressure ("PROVHILO") trial is a worldwide investigator-initiated multicenter randomized controlled two-arm study. Nine hundred patients scheduled for non-laparoscopic abdominal surgery at high or intermediate risk for post-operative pulmonary complications are randomized to mechanical ventilation with the level of PEEP at 12 cmH(2)O with recruitment maneuvers (the lung-protective strategy) or mechanical ventilation with the level of PEEP at maximum 2 cmH(2)O without recruitment maneuvers (the conventional strategy). The primary endpoint is any post-operative pulmonary complication. The PROVHILO trial is the first randomized controlled trial powered to investigate whether an open lung mechanical ventilation strategy in short-term mechanical ventilation prevents against postoperative pulmonary complications. ISRCTN: ISRCTN70332574.

[Monitorization of respiratory mechanics in the ventilated patient].

PubMed

García-Prieto, E; Amado-Rodríguez, L; Albaiceta, G M

2014-01-01

Monitoring during mechanical ventilation allows the measurement of different parameters of respiratory mechanics. Accurate interpretation of these data can be useful for characterizing the situation of the different components of the respiratory system, and for guiding ventilator settings. In this review, we describe the basic concepts of respiratory mechanics, their interpretation, and their potential use in fine-tuning mechanical ventilation. Copyright © 2013 Elsevier España, S.L. y SEMICYUC. All rights reserved.

Trends in mechanical ventilation: are we ventilating our patients in the best possible way?

PubMed Central

Veneroni, Chiara; Farre’, Ramon

2017-01-01

This review addresses how the combination of physiology, medicine and engineering principles contributed to the development and advancement of mechanical ventilation, emphasising the most urgent needs for improvement and the most promising directions of future development. Several aspects of mechanical ventilation are introduced, highlighting on one side the importance of interdisciplinary research for further development and, on the other, the importance of training physicians sufficiently on the technological aspects of modern devices to exploit properly the great complexity and potentials of this treatment. Educational aims To learn how mechanical ventilation developed in recent decades and to provide a better understanding of the actual technology and practice. To learn how and why interdisciplinary research and competences are necessary for providing the best ventilation treatment to patients. To understand which are the most relevant technical limitations in modern mechanical ventilators that can affect their performance in delivery of the treatment. To better understand and classify ventilation modes. To learn the classification, benefits, drawbacks and future perspectives of automatic ventilation tailoring algorithms. PMID:28620428

Criteria for Postoperative Mechanical Ventilation After Thymectomy in Patients With Myasthenia Gravis: A Retrospective Analysis.

PubMed

Chigurupati, Keerthi; Gadhinglajkar, Shrinivas; Sreedhar, Rupa; Nair, Muraleedharan; Unnikrishnan, Madathipat; Pillai, Manjusha

2018-02-01

To determine the criteria for postoperative mechanical ventilation after thymectomy in patients with Myasthenia Gravis. Retrospective study. Teritiary care centre. 77 Myasthenia gravis patients operated for thymectomy were studied. After obtaining clearance from Institutional ethics committee, medical records of 77 patients with MG, who were operated for thymectomy between January 2005 and December 2015 were reviewed in a retrospective manner. Perioperative variables collected from the patient records were demographic data, duration of the disease, Osserman and Genkin classification, Anti-acetylcholine antibody (AChR) positivity, preoperative daily dose of drug, history of preoperative myasthenic crisis, preoperative vital capacity, technique of anesthesia, drugs used for anesthesia, perioperative complications, and duration of postoperative mechanical ventilation. The patients were divided into two groups, group I and group II consisting of those who required postoperative ventilation for < 300 minutes and > 300 minutes, respectively. The determinants of prolonged postoperative ventilation were studied. The requirement of mechanical ventilation was higher in patients with higher Osserman's grade of myasthenia gravis. Duration of the disease had no effect on the duration of mechanical ventilation in myasthenic patients post thymectomy (p = 0.89). The patients with a preoperative history of myasthenic crisis had a requirement for prolonged mechanical ventilation (p=0.03). Patients with preoperative vital capacity < 2.9 litres and preoperative CT scan showing thymoma had a requirement for prolonged mechanical ventilation with p values < 0.001 and 0.035, respectively. Patients who showed positivity for anti-acetylcholine antibodies had a prolonged mechanical ventilation (p=0.026). Preoperative dose of pyridostigmine and the choice of continuation or discontinuation of antcholinesterases on the day of surgery had no influence on the duration of mechanical ventilation (p value of 0.19 and 0.36 respectively). Epidural analgesia intra and postoperatively significantly reduced the requirement of mechanical ventilation (p=0.006). The predictors of postoperative ventilation in myasthenic patients undergoing thymectomy as per our study are: 1. Grade of myasthenia; 2. History of preoperative myasthenic crisis; 3. Anti-acetylcholine antibodies positivity; 4. Presence of thymoma; and 5. a vital capacity < 2.9 litres. Use of thoracic epidural as a part of combined anesthetic technique helps to reduce the need of mechanical ventilation in these patients. Copyright © 2018 Elsevier Inc. All rights reserved.

Clinical review: Long-term noninvasive ventilation

PubMed Central

Robert, Dominique; Argaud, Laurent

2007-01-01

Noninvasive positive ventilation has undergone a remarkable evolution over the past decades and is assuming an important role in the management of both acute and chronic respiratory failure. Long-term ventilatory support should be considered a standard of care to treat selected patients following an intensive care unit (ICU) stay. In this setting, appropriate use of noninvasive ventilation can be expected to improve patient outcomes, reduce ICU admission, enhance patient comfort, and increase the efficiency of health care resource utilization. Current literature indicates that noninvasive ventilation improves and stabilizes the clinical course of many patients with chronic ventilatory failure. Noninvasive ventilation also permits long-term mechanical ventilation to be an acceptable option for patients who otherwise would not have been treated if tracheostomy were the only alternative. Nevertheless, these results appear to be better in patients with neuromuscular/-parietal disorders than in chronic obstructive pulmonary disease. This clinical review will address the use of noninvasive ventilation (not including continuous positive airway pressure) mainly in diseases responsible for chronic hypoventilation (that is, restrictive disorders, including neuromuscular disease and lung disease) and incidentally in others such as obstructive sleep apnea or problems of central drive. PMID:17419882

Effects of positive end-expiratory pressure and recruitment maneuvers in a ventilator-induced injury mouse model

PubMed Central

Franzi, Lisa M.; Linderholm, Angela L.; Last, Jerold A.; Adams, Jason Y.; Harper, Richart W.

2017-01-01

Background Positive-pressure mechanical ventilation is an essential therapeutic intervention, yet it causes the clinical syndrome known as ventilator-induced lung injury. Various lung protective mechanical ventilation strategies have attempted to reduce or prevent ventilator-induced lung injury but few modalities have proven effective. A model that isolates the contribution of mechanical ventilation on the development of acute lung injury is needed to better understand biologic mechanisms that lead to ventilator-induced lung injury. Objectives To evaluate the effects of positive end-expiratory pressure and recruitment maneuvers in reducing lung injury in a ventilator-induced lung injury murine model in short- and longer-term ventilation. Methods 5–12 week-old female BALB/c mice (n = 85) were anesthetized, placed on mechanical ventilation for either 2 hrs or 4 hrs with either low tidal volume (8 ml/kg) or high tidal volume (15 ml/kg) with or without positive end-expiratory pressure and recruitment maneuvers. Results Alteration of the alveolar-capillary barrier was noted at 2 hrs of high tidal volume ventilation. Standardized histology scores, influx of bronchoalveolar lavage albumin, proinflammatory cytokines, and absolute neutrophils were significantly higher in the high-tidal volume ventilation group at 4 hours of ventilation. Application of positive end-expiratory pressure resulted in significantly decreased standardized histology scores and bronchoalveolar absolute neutrophil counts at low- and high-tidal volume ventilation, respectively. Recruitment maneuvers were essential to maintain pulmonary compliance at both 2 and 4 hrs of ventilation. Conclusions Signs of ventilator-induced lung injury are evident soon after high tidal volume ventilation (as early as 2 hours) and lung injury worsens with longer-term ventilation (4 hrs). Application of positive end-expiratory pressure and recruitment maneuvers are protective against worsening VILI across all time points. Dynamic compliance can be used guide the frequency of recruitment maneuvers to help ameloriate ventilator-induced lung injury. PMID:29112971

Prediction of inspired oxygen fraction for targeted arterial oxygen tension following open heart surgery in non-smoking and smoking patients.

PubMed

Bou-Khalil, Pierre; Zeineldine, Salah; Chatburn, Robert; Ayyoub, Chakib; Elkhatib, Farouk; Bou-Akl, Imad; El-Khatib, Mohamad

2017-10-01

Simple and accurate expressions describing the P a O 2 -F i O 2 relationship in mechanically ventilated patients are lacking. The current study aims to validate a novel mathematical expression for accurate prediction of the fraction of inspired oxygen that will result in a targeted arterial oxygen tension in non-smoking and smoking patients receiving mechanical ventilation following open heart surgeries. One hundred P a O 2 -F i O 2 data pairs were obtained from 25 non-smoking patients mechanically ventilated following open heart surgeries. One data pair was collected at each of F i O 2 of 40, 60, 80, and 100% while maintaining same mechanical ventilation support settings. Similarly, another 100 hundred P a O 2 -F i O 2 data pairs were obtained from 25 smoking patients mechanically ventilated following open heart surgeries. The utility of the new mathematical expression in accurately describing the P a O 2 -F i O 2 relationship in these patients was assessed by the regression and Bland-Altman analyses. Significant correlations were seen between the true and estimated F i O 2 values in non-smoking (r 2  = 0.9424; p < 0.05) and smoking (r 2  = 0.9466; p < 0.05) patients. Tight biases between the true and estimated F i O 2 values for non-smoking (3.1%) and smoking (4.1%) patients were observed. Also, significant correlations were seen between the true and estimated P a O 2 /F i O 2 ratios in non-smoking (r 2  = 0.9530; p < 0.05) and smoking (r 2  = 0.9675; p < 0.05) patients. Tight biases between the true and estimated P a O 2 /F i O 2 ratios for non-smoking (-18 mmHg) and smoking (-16 mmHg) patients were also observed. The new mathematical expression for the description of the P a O 2 -F i O 2 relationship is valid and accurate in non-smoking and smoking patients who are receiving mechanical ventilation for post cardiac surgery.

Prone position in patients with acute respiratory distress syndrome

PubMed Central

Setten, Mariano; Plotnikow, Gustavo Adrián; Accoce, Matías

2016-01-01

Acute respiratory distress syndrome occupies a great deal of attention in intensive care units. Despite ample knowledge of the physiopathology of this syndrome, the focus in intensive care units consists mostly of life-supporting treatment and avoidance of the side effects of invasive treatments. Although great advances in mechanical ventilation have occurred in the past 20 years, with a significant impact on mortality, the incidence continues to be high. Patients with acute respiratory distress syndrome, especially the most severe cases, often present with refractory hypoxemia due to shunt, which can require additional treatments beyond mechanical ventilation, among which is mechanical ventilation in the prone position. This method, first recommended to improve oxygenation in 1974, can be easily implemented in any intensive care unit with trained personnel. Prone position has extremely robust bibliographic support. Various randomized clinical studies have demonstrated the effect of prone decubitus on the oxygenation of patients with acute respiratory distress syndrome measured in terms of the PaO2/FiO2 ratio, including its effects on increasing patient survival. The members of the Respiratory Therapists Committee of the Sociedad Argentina de Terapia Intensiva performed a narrative review with the objective of discovering the available evidence related to the implementation of prone position, changes produced in the respiratory system due to the application of this maneuver, and its impact on mortality. Finally, guidelines are suggested for decision-making. PMID:27925054

Artificial humidification for the mechanically ventilated patient.

PubMed

Selvaraj, N

Caring for patients who are mechanically ventilated poses many challenges for critical care nurses. It is important to humidify the patient's airways artificially to prevent complications such as ventilator-associated pneumonia. There is no gold standard to determine which type of humidification is best for patients who are artificially ventilated. This article provides an overview of commonly used artificial humidification for mechanically ventilated patients and discusses nurses' responsibilities in caring for patients receiving artificial humidification.

Non-invasive mechanical ventilation and mortality in elderly immunocompromised patients hospitalized with pneumonia: a retrospective cohort study.

PubMed

Johnson, Christopher S; Frei, Christopher R; Metersky, Mark L; Anzueto, Antonio R; Mortensen, Eric M

2014-01-27

Mortality after pneumonia in immunocompromised patients is higher than for immunocompetent patients. The use of non-invasive mechanical ventilation for patients with severe pneumonia may provide beneficial outcomes while circumventing potential complications associated with invasive mechanical ventilation. The aim of our study was to determine if the use of non-invasive mechanical ventilation in elderly immunocompromised patients with pneumonia is associated with higher all-cause mortality. In this retrospective cohort study, data were obtained from the Department of Veterans Affairs administrative databases. We included veterans age ≥65 years who were immunocompromised and hospitalized due to pneumonia. Multilevel logistic regression analysis was used to determine the relationship between the use of invasive versus non-invasive mechanical ventilation and 30-day and 90-day mortality. Of 1,946 patients in our cohort, 717 received non-invasive mechanical ventilation and 1,229 received invasive mechanical ventilation. There was no significant association between all-cause 30-day mortality and non-invasive versus invasive mechanical ventilation in our adjusted model (odds ratio (OR) 0.85, 95% confidence interval (CI) 0.66-1.10). However, those patients who received non-invasive mechanical ventilation had decreased 90-day mortality (OR 0.66, 95% CI 0.52-0.84). Additionally, receipt of guideline-concordant antibiotics in our immunocompromised cohort was significantly associated with decreased odds of 30-day mortality (OR 0.31, 95% CI 0.24-0.39) and 90-day mortality (OR 0.41, 95% CI 0.31-0.53). Our findings suggest that physicians should consider the use of non-invasive mechanical ventilation, when appropriate, for elderly immunocompromised patients hospitalized with pneumonia.

Influence of Mechanical Ventilation on the Incidence of Pneumothorax During Infraclavicular Subclavian Vein Catheterization: A Prospective Randomized Noninferiority Trial.

PubMed

Kim, Eugene; Kim, Hyun Joo; Hong, Deok Man; Park, Hee-Pyoung; Bahk, Jae-Hyon

2016-09-01

It remains unclear whether we have to interrupt mechanical ventilation during infraclavicular subclavian venous catheterization. In practice, the clinicians' choice about lung deflation depends on their own discretion. The purpose of this study was to assess the influence of mechanical ventilation on the incidence of pneumothorax during infraclavicular subclavian venous catheterization. A total of 332 patients, who needed subclavian venous catheterization, were randomly assigned to 1 of the 2 groups: catheterizations were performed with the patients' lungs under mechanical ventilation (ventilation group, n = 165) or without mechanical ventilation (deflation group, n = 167). The incidences of pneumothorax and other complications such as arterial puncture, hemothorax, or catheter misplacements and the success rate of catheterization were compared. The incidences of pneumothorax were 0% (0/165) in the ventilation group and 0.6% (1/167) in the deflation group. The incidence of pneumothorax in the deflation group was 0.6% higher than that in the ventilation group and the 2-sided 90% confidence interval for the difference was (-1.29% to 3.44%). Because the lower bound for the 2-sided 90% confidence interval, -1.29%, was higher than the predefined noninferiority margin of -3%, the inferiority of the ventilation group over the deflation group was rejected at the .05 level of significance. Other complication rates and success rates of catheterization were comparable between 2 groups. The oxygen saturation dropped below 95% in 9 patients in the deflation group, while none in the ventilation group (P = .007). The success and complication rates were similar regardless of mechanical ventilation. During infraclavicular subclavian venous catheterization, interruption of mechanical ventilation does not seem to be necessary for the prevention of pneumothorax.

Tidal volume in acute respiratory distress syndrome: how best to select it.

PubMed

Umbrello, Michele; Marino, Antonella; Chiumello, Davide

2017-07-01

Mechanical ventilation is the type of organ support most widely provided in the intensive care unit. However, this form of support does not constitute a cure for acute respiratory distress syndrome (ARDS), as it mainly works by buying time for the lungs to heal while contributing to the maintenance of vital gas exchange. Moreover, it can further damage the lung, leading to the development of a particular form of lung injury named ventilator-induced lung injury (VILI). Experimental evidence accumulated over the last 30 years highlighted the factors associated with an injurious form of mechanical ventilation. The present paper illustrates the physiological effects of delivering a tidal volume to the lungs of patients with ARDS, and suggests an approach to tidal volume selection. The relationship between tidal volume and the development of VILI, the so called volotrauma, will be reviewed. The still actual suggestion of a lung-protective ventilatory strategy based on the use of low tidal volumes scaled to the predicted body weight (PBW) will be presented, together with newer strategies such as the use of airway driving pressure as a surrogate for the amount of ventilatable lung tissue or the concept of strain, i.e., the ratio between the tidal volume delivered relative to the resting condition, that is the functional residual capacity (FRC). An ultra-low tidal volume strategy with the use of extracorporeal carbon dioxide removal (ECCO 2 R) will be presented and discussed. Eventually, the role of other ventilator-related parameters in the generation of VILI will be considered (namely, plateau pressure, airway driving pressure, respiratory rate (RR), inspiratory flow), and the promising unifying framework of mechanical power will be presented.

Tidal volume in acute respiratory distress syndrome: how best to select it

PubMed Central

Umbrello, Michele; Marino, Antonella

2017-01-01

Mechanical ventilation is the type of organ support most widely provided in the intensive care unit. However, this form of support does not constitute a cure for acute respiratory distress syndrome (ARDS), as it mainly works by buying time for the lungs to heal while contributing to the maintenance of vital gas exchange. Moreover, it can further damage the lung, leading to the development of a particular form of lung injury named ventilator-induced lung injury (VILI). Experimental evidence accumulated over the last 30 years highlighted the factors associated with an injurious form of mechanical ventilation. The present paper illustrates the physiological effects of delivering a tidal volume to the lungs of patients with ARDS, and suggests an approach to tidal volume selection. The relationship between tidal volume and the development of VILI, the so called volotrauma, will be reviewed. The still actual suggestion of a lung-protective ventilatory strategy based on the use of low tidal volumes scaled to the predicted body weight (PBW) will be presented, together with newer strategies such as the use of airway driving pressure as a surrogate for the amount of ventilatable lung tissue or the concept of strain, i.e., the ratio between the tidal volume delivered relative to the resting condition, that is the functional residual capacity (FRC). An ultra-low tidal volume strategy with the use of extracorporeal carbon dioxide removal (ECCO2R) will be presented and discussed. Eventually, the role of other ventilator-related parameters in the generation of VILI will be considered (namely, plateau pressure, airway driving pressure, respiratory rate (RR), inspiratory flow), and the promising unifying framework of mechanical power will be presented. PMID:28828362

Mechanical ventilation causes pulmonary mitochondrial dysfunction and delayed alveolarization in neonatal mice.

PubMed

Ratner, Veniamin; Sosunov, Sergey A; Niatsetskaya, Zoya V; Utkina-Sosunova, Irina V; Ten, Vadim S

2013-12-01

Hyperoxia inhibits pulmonary bioenergetics, causing delayed alveolarization in mice. We hypothesized that mechanical ventilation (MV) also causes a failure of bioenergetics to support alveolarization. To test this hypothesis, neonatal mice were ventilated with room air for 8 hours (prolonged) or for 2 hours (brief) with 15 μl/g (aggressive) tidal volume (Tv), or for 8 hours with 8 μl/g (gentle) Tv. After 24 hours or 10 days of recovery, lung mitochondria were examined for adenosine diphosphate (ADP)-phosphorylating respiration, using complex I (C-I)-dependent, complex II (C-II)-dependent, or cytochrome C oxidase (C-IV)-dependent substrates, ATP production rate, and the activity of C-I and C-II. A separate cohort of mice was exposed to 2,4-dinitrophenol (DNP), a known uncoupler of oxidative phosphorylation. At 10 days of recovery, pulmonary alveolarization and the expression of vascular endothelial growth factor (VEGF) were assessed. Sham-operated littermates were used as control mice. At 24 hours after aggressive MV, mitochondrial ATP production rates and the activity of C-I and C-II were significantly decreased compared with control mice. However, at 10 days of recovery, only mice exposed to prolonged-aggressive MV continued to exhibit significantly depressed mitochondrial respiration. This was associated with significantly poorer alveolarization and VEGF expression. In contrast, mice exposed to brief-aggressive or prolonged-gentle MV exhibited restored mitochondrial ADP-phosphorylation, normal alveolarization and pulmonary VEGF content. Exposure to DNP fully replicated the phenotype consistent with alveolar developmental arrest. Our data suggest that the failure of bioenergetics to support normal lung development caused by aggressive and prolonged ventilation should be considered a fundamental mechanism for the development of bronchopulmonary dysplasia in premature neonates.

Atelectasis after airway extubation during veno-arterial extracorporeal membrane oxygenation support.

PubMed

Wang, Hong; Jia, Ming; Mao, Bin; Hou, Xiaotong

2017-09-01

Veno-arterial extracorporeal membrane oxygenation (VA ECMO) is used in cardiopulmonary failure patients to provide temporary assisted circulation. Usually, prolonged intubation and invasive mechanical ventilation are required in patients with ECMO support. We report on two cases of patients who had no pre-existing injuries of the affected lung, underwent VA ECMO support after open-heart surgery and received airway extubation (AE) or awake ECMO with the recovery of left ventricular ejection fraction. Atelectasis happened after AE and non-invasive positive pressure ventilation attenuated the atelectasis of one patient. The atelectasis of the other patient was corrected 10 hours after weaning from ECMO. Both patients were discharged successfully. Awake VA ECMO for post-cardiac surgery patients should be performed with prudence and needs further research.

Surgical Closure of Patent Ductus Arteriosus in Premature Neonates Weighing Less Than 1,000 grams: Contemporary Outcomes.

PubMed

Lehenbauer, David G; Fraser, Charles D; Crawford, Todd C; Hibino, Naru; Aucott, Susan; Grimm, Joshua C; Patel, Nishant; Magruder, J Trent; Cameron, Duke E; Vricella, Luca

2018-07-01

The safety of surgical closure of patent ductus arteriosus (PDA) in very low birth weight premature neonates has been questioned because of associated morbidities. However, these studies are vulnerable to significant bias as surgical ligation has historically been utilized as "rescue" therapy. The objective of this study was to review our institutions' outcomes of surgical PDA ligation. All neonates with operative weight of ≤1.00 kg undergoing surgical PDA ligation from 2003 to 2015 were analyzed. Records were queried to identify surgical complications, perioperative morbidity, and mortality. Outcomes included pre- and postoperative ventilator requirements, pre- and postoperative inotropic support, acute kidney injury, surgical complications, and 30-day mortality. One hundred sixty-six preterm neonates underwent surgical ligation. One hundred twenty-one (70.3%) had failed indomethacin closure. One hundred sixty-four (98.8%) patients required mechanical ventilation prior to surgery. At 17 postoperative days, freedom from the ventilator reached 50%. Of 109 (66.4%) patients requiring prolonged preoperative inotropic support, 59 (54.1%) were liberated from inotropes by postoperative day 1. Surgical morbidity was encountered in four neonates (2.4%): two (1.2%) patients had a postoperative pneumothorax requiring tube thoracostomy, one (0.6%) patient had a recurrent laryngeal nerve injury, and one (0.6%) patient had significant intraoperative bleeding. The 30-day all-cause mortality was 1.8% (n = 3); no deaths occurred intraoperatively. In this retrospective investigation, surgical PDA closure was associated with low 30-day mortality and minimal morbidity and resulted in rapid discontinuation of inotropic support and weaning from mechanical ventilation. Given the safety of this intervention, surgical PDA ligation merits consideration in the management strategy of the preterm neonate with a PDA.

Effects of Modes, Obesity, and Body Position on Non-invasive Positive Pressure Ventilation Success in the Intensive Care Unit: A Randomized Controlled Study.

PubMed

Türk, Murat; Aydoğdu, Müge; Gürsel, Gül

2018-01-01

Different outcomes and success rates of non-invasive positive pressure ventilation (NPPV) in patients with acute hypercapnic respiratory failure (AHRF) still pose a significant problem in intensive care units. Previous studies investigating different modes, body positioning, and obesity-associated hypoventilation in patients with chronic respiratory failure showed that these factors may affect ventilator mechanics to achieve a better minute ventilation. This study tried to compare pressure support (BiPAP-S) and average volume targeted pressure support (AVAPS-S) modes in patients with acute or acute-on-chronic hypercapnic respiratory failure. In addition, short-term effects of body position and obesity within both modes were analyzed. We conducted a randomized controlled study in a 7-bed intensive care unit. The course of blood gas analysis and differences in ventilation variables were compared between BiPAP-S (n=33) and AVAPS-S (n=29), and between semi-recumbent and lateral positions in both modes. No difference was found in the length of hospital stay and the course of PaCO2, pH, and HCO3 levels between the modes. There was a mean reduction of 5.7±4.1 mmHg in the PaCO2 levels in the AVAPS-S mode, and 2.7±2.3 mmHg in the BiPAP-S mode per session (p<0.05). Obesity didn't have any effect on the course of PaCO2 in both the modes. Body positioning had no notable effect in both modes. Although the decrease in the PaCO2 levels in the AVAPS-S mode per session was remarkably high, the course was similar in both modes. Furthermore, obesity and body positioning had no prominent effect on the PaCO2 response and ventilator mechanics. Post hoc power analysis showed that the sample size was not adequate to detect a significant difference between the modes.

[Likeness between respiratory responses on CO2 in conditions of natural breathing and voluntary-controlled mechanical ventilation].

PubMed

Pogodin, M A; Granstrem, M P; Dimitrienko, A I

2007-04-01

We did Read CO2 rebreathing tests in 8 adult males. Both at natural breathing, and at self-controlled mechanical ventilation, volunteers increased ventilation proportionally to growth end-tidal PCO2. Inside individual distinctions of responses to CO2 during controlled mechanical ventilation are result of the voluntary motor control.

Efficacy and safety of bubble CPAP in neonatal care in low and middle income countries: a systematic review.

PubMed

Martin, Simone; Duke, Trevor; Davis, Peter

2014-11-01

Forty per cent of global child deaths occur in the neonatal period. Low and middle income countries need effective and simple methods to improve hospital-based neonatal care. Bubble continuous positive airway pressure (CPAP) may have a role in improving the quality of respiratory support in hospitals in low and middle income countries. To examine the evidence for the efficacy and safety of bubble CPAP in neonates with respiratory distress in low and middle income settings. A systematic search (1946-March 2014) was performed of Pubmed, Ovid MEDLINE, Web of Science, Google Scholar and the references of relevant articles. Articles meeting inclusion criteria (CPAP for respiratory distress in infants <28 days of age in hospitals in low and middle income countries) were assessed using Grading of Recommendations, Assessment, Development and Evaluation and Newcastle-Ottawa Quality Assessment Scale methodology. Outcomes included need for mechanical ventilation, complications and mortality. In three studies, the initial use of bubble CPAP compared with oxygen therapy, followed by mechanical ventilation if required, reduced the need for mechanical ventilation by 30%-50%. In another three trials comparing bubble CPAP with ventilator CPAP, mortality and complication rates were similar, while meta-analysis of CPAP failure in these same trials showed a lower failure rate in the bubble CPAP groups (p <0.003). There is evidence that bubble CPAP is safe and reduces the need for mechanical ventilation. Further research into the efficacy of bubble CPAP in low-income and middle-income countries is needed. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Heliox Improves Carbon Dioxide Removal during Lung Protective Mechanical Ventilation.

PubMed

Beurskens, Charlotte J; Brevoord, Daniel; Lagrand, Wim K; van den Bergh, Walter M; Vroom, Margreeth B; Preckel, Benedikt; Horn, Janneke; Juffermans, Nicole P

2014-01-01

Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2) diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical ventilation using low tidal volumes. Methods. This is an observational cohort substudy of a single arm intervention study. Twenty-four ICU patients were included, who were admitted after a cardiac arrest and mechanically ventilated for 3 hours with heliox (50% helium; 50% oxygen). A fixed protective ventilation protocol (6 mL/kg) was used, with prospective observation for changes in lung mechanics and gas exchange. Statistics was by Bonferroni post-hoc correction with statistical significance set at P < 0.017. Results. During heliox ventilation, respiratory rate decreased (25 ± 4 versus 23 ± 5 breaths min(-1), P = 0.010). Minute volume ventilation showed a trend to decrease compared to baseline (11.1 ± 1.9 versus 9.9 ± 2.1 L min(-1), P = 0.026), while reducing PaCO2 levels (5.0 ± 0.6 versus 4.5 ± 0.6 kPa, P = 0.011) and peak pressures (21.1 ± 3.3 versus 19.8 ± 3.2 cm H2O, P = 0.024). Conclusions. Heliox improved CO2 elimination while allowing reduced minute volume ventilation in adult patients during protective mechanical ventilation.

[Pulmonary complications associated with mechanical ventilation in neonates].

PubMed

Torres-Castro, Cristabel; Valle-Leal, Jaime; Martínez-Limón, Alba J; Lastra-Jiménez, Zaira; Delgado-Bojórquez, Lesvia Carmina

To determine the incidence of0 associated with mechanical ventilation in patients admitted to a service in a second level hospital NICU. Retrospective analytical study records of newborns admitted to NICU room and receiving mechanical ventilation in a secondary hospital health care. Demographic data, of mechanical ventilation, intubation and complications reported in the clinical record were collected and analyzed in SPSS 20. 53 patients selected a total of 40 complications found. The annual incidence of pulmonary complications associated with mechanical ventilation in the area of service neonatology NICU, at a second level hospital at Sonora was 49.05% (95% CI 0.35 to 0.62). The most frequent pulmonary complications were atelectasis 35%, pneumonia 27.5%, pneumothorax 15%, bronchopulmonary dysplasia 15%, pneumomediastinum 15% and pulmonary hemorrhage 2.5%. The presentation of pulmonary complications secondary to mechanical ventilation in neonatal patients is similar to that reported in developing countries. Atelectasis is the most common pulmonary complication in neonatal patients undergoing mechanical ventilation. Copyright © 2016 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

A new system for understanding modes of mechanical ventilation.

PubMed

Chatburn, R L; Primiano, F P

2001-06-01

Numerous ventilation modes and ventilation options have become available as new mechanical ventilators have reached the market. Ventilator manufacturers have no standardized terminology for ventilator modes and ventilation options, and ventilator operator's manuals do not help the clinician compare the modes of ventilators from different manufacturers. This article proposes a standardized system for classifying ventilation modes, based on general engineering principles and a small set of explicit definitions. Though there may be resistance by ventilator manufacturers to a standardized system of ventilation terminology, clinicians and health care equipment purchasers should adopt such a system in the interest of clear communication--the lack of which prevents clinicians from fully understanding the therapies they administer and could compromise the quality of patient care.

[Mechanical ventilation in acute asthma crisis].

PubMed

Barbas, Carmen Sílvia Valente; Pinheiro, Bruno do Valle; Vianna, Arthur; Magaldi, Ricardo; Casati, Ana; José, Anderson; Okamoto, Valdelis Novis

2007-06-01

The II Brazilian Consensus Conference on Mechanical Ventilation was published in 2000. Knowledge on the field of mechanical ventilation evolved rapidly since then, with the publication of numerous clinical studies with potential impact on the ventilatory management of critically ill patients. Moreover, the evolving concept of evidence - based medicine determined the grading of clinical recommendations according to the methodological value of the studies on which they are based. This explicit approach has broadened the understanding and adoption of clinical recommendations. For these reasons, AMIB - Associação de Medicina Intensiva Brasileira and SBPT - Sociedade Brasileira de Pneumologia e Tisiologia - decided to update the recommendations of the II Brazilian Consensus. Mechanical ventilation in the asthma attack has been one of the updated topics. Describe the most important topics on the mechanical ventilation during the asthma attack and suggest the main therapeutic approaches. Systematic review of the published literature and gradation of the studies in levels of evidence, using the key words "mechanical ventilation" and "asthma". We present recommendations on the ventilatory modes and settings to be adopted when ventilating a patient during an asthma attack, as well as the recommended monitoring. Alternative ventilation techniques are also presented. Protective ventilatory strategies are recommended when ventilating a patient during a severe asthma attack.

Nebulized heparin is associated with fewer days of mechanical ventilation in critically ill patients: a randomized controlled trial.

PubMed

Dixon, Barry; Schultz, Marcus J; Smith, Roger; Fink, James B; Santamaria, John D; Campbell, Duncan J

2010-01-01

Prolonged mechanical ventilation has the potential to aggravate or initiate pulmonary inflammation and cause lung damage through fibrin deposition. Heparin may reduce pulmonary inflammation and fibrin deposition. We therefore assessed whether nebulized heparin improved lung function in patients expected to require prolonged mechanical ventilation. Fifty patients expected to require mechanical ventilation for more than 48 hours were enrolled in a double-blind randomized placebo-controlled trial of nebulized heparin (25,000 U) or placebo (normal saline) 4 or 6 hourly, depending on patient height. The study drug was continued while the patient remained ventilated to a maximum of 14 days from randomization. Nebulized heparin was not associated with a significant improvement in the primary end-point, the average daily partial pressure of oxygen to inspired fraction of oxygen ratio while mechanically ventilated, but was associated with improvement in the secondary end-point, ventilator-free days amongst survivors at day 28 (22.6 ± 4.0 versus 18.0 ± 7.1, treatment difference 4.6 days, 95% CI 0.9 to 8.3, P = 0.02). Heparin administration was not associated with any increase in adverse events. Nebulized heparin was associated with fewer days of mechanical ventilation in critically ill patients expected to require prolonged mechanical ventilation. Further trials are required to confirm these findings. The Australian Clinical Trials Registry (ACTR-12608000121369).

Association Between Noninvasive Ventilation and Mortality Among Older Patients With Pneumonia

PubMed Central

Valley, Thomas S.; Walkey, Allan J.; Lindenauer, Peter K.; Wiener, Renda Soylemez; Cooke, Colin R.

2016-01-01

Objective Despite increasing use, evidence is mixed as to the appropriate use of noninvasive ventilation in patients with pneumonia. We aimed to determine the relationship between receipt of noninvasive ventilation and outcomes for patients with pneumonia in a real-world setting. Design, Setting, Patients We performed a retrospective cohort study of Medicare beneficiaries (aged > 64 yr) admitted to 2,757 acute-care hospitals in the United States with pneumonia, who received mechanical ventilation from 2010 to 2011. Exposures Noninvasive ventilation versus invasive mechanical ventilation. Measurement and Main Results The primary outcome was 30-day mortality with Medicare reimbursement as a secondary outcome. To account for unmeasured confounding associated with noninvasive ventilation use, an instrumental variable was used—the differential distance to a high noninvasive ventilation use hospital. All models were adjusted for patient and hospital characteristics to account for measured differences between groups. Among 65,747 Medicare beneficiaries with pneumonia who required mechanical ventilation, 12,480 (19%) received noninvasive ventilation. Patients receiving noninvasive ventilation were more likely to be older, male, white, rural-dwelling, have fewer comorbidities, and were less likely to be acutely ill as measured by organ failures. Results of the instrumental variable analysis suggested that, among marginal patients, receipt of noninvasive ventilation was not significantly associated with differences in 30-day mortality when compared with invasive mechanical ventilation (54% vs 55%; p = 0.92; 95% CI of absolute difference, –13.8 to 12.4) but was associated with significantly lower Medicare spending ($18,433 vs $27,051; p = 0.02). Conclusions Among Medicare beneficiaries hospitalized with pneumonia who received mechanical ventilation, noninvasive ventilation use was not associated with a real-world mortality benefit. Given the wide CIs, however, substantial harm associated with noninvasive ventilation could not be excluded. The use of noninvasive ventilation for patients with pneumonia should be cautioned, but targeted enrollment of marginal patients with pneumonia could enrich future randomized trials. PMID:27749319

Monitoring of intratidal lung mechanics: a Graphical User Interface for a model-based decision support system for PEEP-titration in mechanical ventilation.

PubMed

Buehler, S; Lozano-Zahonero, S; Schumann, S; Guttmann, J

2014-12-01

In mechanical ventilation, a careful setting of the ventilation parameters in accordance with the current individual state of the lung is crucial to minimize ventilator induced lung injury. Positive end-expiratory pressure (PEEP) has to be set to prevent collapse of the alveoli, however at the same time overdistension should be avoided. Classic approaches of analyzing static respiratory system mechanics fail in particular if lung injury already prevails. A new approach of analyzing dynamic respiratory system mechanics to set PEEP uses the intratidal, volume-dependent compliance which is believed to stay relatively constant during one breath only if neither atelectasis nor overdistension occurs. To test the success of this dynamic approach systematically at bedside or in an animal study, automation of the computing steps is necessary. A decision support system for optimizing PEEP in form of a Graphical User Interface (GUI) was targeted. Respiratory system mechanics were analyzed using the gliding SLICE method. The resulting shapes of the intratidal compliance-volume curve were classified into one of six categories, each associated with a PEEP-suggestion. The GUI should include a graphical representation of the results as well as a quality check to judge the reliability of the suggestion. The implementation of a user-friendly GUI was successfully realized. The agreement between modelled and measured pressure data [expressed as root-mean-square (RMS)] tested during the implementation phase with real respiratory data from two patient studies was below 0.2 mbar for data taken in volume controlled mode and below 0.4 mbar for data taken in pressure controlled mode except for two cases with RMS < 0.6 mbar. Visual inspections showed, that good and medium quality data could be reliably identified. The new GUI allows visualization of intratidal compliance-volume curves on a breath-by-breath basis. The automatic categorisation of curve shape into one of six shape-categories provides the rational decision-making model for PEEP-titration.

Particle size distribution and composition in a mechanically ventilated school building during air pollution episodes.

PubMed

Parker, J L; Larson, R R; Eskelson, E; Wood, E M; Veranth, J M

2008-10-01

Particle count-based size distribution and PM(2.5) mass were monitored inside and outside an elementary school in Salt Lake City (UT, USA) during the winter atmospheric inversion season. The site is influenced by urban traffic and the airshed is subject to periods of high PM(2.5) concentration that is mainly submicron ammonium and nitrate. The school building has mechanical ventilation with filtration and variable-volume makeup air. Comparison of the indoor and outdoor particle size distribution on the five cleanest and five most polluted school days during the study showed that the ambient submicron particulate matter (PM) penetrated the building, but indoor concentrations were about one-eighth of outdoor levels. The indoor:outdoor PM(2.5) mass ratio averaged 0.12 and particle number ratio for sizes smaller than 1 microm averaged 0.13. The indoor submicron particle count and indoor PM(2.5) mass increased slightly during pollution episodes but remained well below outdoor levels. When the building was occupied the indoor coarse particle count was much higher than ambient levels. These results contribute to understanding the relationship between ambient monitoring station data and the actual human exposure inside institutional buildings. The study confirms that staying inside a mechanically ventilated building reduces exposure to outdoor submicron particles. This study supports the premise that remaining inside buildings during particulate matter (PM) pollution episodes reduces exposure to submicron PM. New data on a mechanically ventilated institutional building supplements similar studies made in residences.

Mechanical Ventilation Outcomes in Patients With Pulmonary Hypertension in the United States: A National Retrospective Cohort Analysis.

PubMed

Rush, Barret; Biagioni, Bradly J; Berger, Landon; McDermid, Robert

2017-12-01

The outcome of patients with pulmonary arterial hypertension (PAH) who undergo mechanical ventilation is not well known. The Nationwide Inpatient Sample for 2006 to 2012 was used to isolate patients with a diagnosis of PAH who also underwent invasive (MV) and noninvasive (NIMV) mechanical ventilation. The primary outcome was in-hospital mortality. The hospital records of 55 208 382 patients were studied, and there were 21 070 patients with PAH, of whom 1646 (7.8%) received MV and 834 (4.0%) received NIMV. Those receiving MV had higher mortality (39.1% vs 12.6%, P < .001) and longer hospital stays (11.9 days, interquartile range [IQR] 6.1-22.2 vs 6.7 days, IQR 3.4-11.9, P < .001) than those undergoing NIMV. Of the patients treated with MV, 4.4% also used home oxygen therapy and had similar overall mortality to those who did not use home oxygen (35.3% vs 39.1%, P = .46). Similarly, there was no relationship between home oxygen use and mortality in patients treated with NIMV (10.6% vs 12.6%, P = .48). Notably, more patients treated with NIMV used home oxygen than those treated with MV (14.4% vs 4.4%, P < .001). Patients with PAH who undergo invasive mechanical ventilation have an in-hospital mortality of 39.1%. Future work may help identify the types of patients who benefit most from advanced respiratory support in a critical care setting.

High-Frequency Oscillatory Ventilation Use and Severe Pediatric ARDS in the Pediatric Hematopoietic Cell Transplant Recipient.

PubMed

Rowan, Courtney M; Loomis, Ashley; McArthur, Jennifer; Smith, Lincoln S; Gertz, Shira J; Fitzgerald, Julie C; Nitu, Mara E; Moser, Elizabeth As; Hsing, Deyin D; Duncan, Christine N; Mahadeo, Kris M; Moffet, Jerelyn; Hall, Mark W; Pinos, Emily L; Tamburro, Robert F; Cheifetz, Ira M

2018-04-01

The effectiveness of high-frequency oscillatory ventilation (HFOV) in the pediatric hematopoietic cell transplant patient has not been established. We sought to identify current practice patterns of HFOV, investigate parameters during HFOV and their association with mortality, and compare the use of HFOV to conventional mechanical ventilation in severe pediatric ARDS. This is a retrospective analysis of a multi-center database of pediatric and young adult allogeneic hematopoietic cell transplant subjects requiring invasive mechanical ventilation for critical illness from 2009 through 2014. Twelve United States pediatric centers contributed data. Continuous variables were compared using a Wilcoxon rank-sum test or a Kruskal-Wallis analysis. For categorical variables, univariate analysis with logistic regression was performed. The database contains 222 patients, of which 85 subjects were managed with HFOV. Of this HFOV cohort, the overall pediatric ICU survival was 23.5% ( n = 20). HFOV survivors were transitioned to HFOV at a lower oxygenation index than nonsurvivors (25.6, interquartile range 21.1-36.8, vs 37.2, interquartile range 26.5-52.2, P = .046). Survivors were transitioned to HFOV earlier in the course of mechanical ventilation, (day 0 vs day 2, P = .002). No subject survived who was transitioned to HFOV after 1 week of invasive mechanical ventilation. We compared subjects with severe pediatric ARDS treated only with conventional mechanical ventilation versus early HFOV (within 2 d of invasive mechanical ventilation) versus late HFOV. There was a trend toward difference in survival (conventional mechanical ventilation 24%, early HFOV 30%, and late HFOV 9%, P = .08). In this large database of pediatric allogeneic hematopoietic cell transplant subjects who had acute respiratory failure requiring invasive mechanical ventilation for critical illness with severe pediatric ARDS, early use of HFOV was associated with improved survival compared to late implementation of HFOV, and the subjects had outcomes similar to those treated only with conventional mechanical ventilation. Copyright © 2018 by Daedalus Enterprises.

Respiratory Mechanics and Plasma Levels of Tumor Necrosis Factor Alpha and Interleukin 6 Are Affected by Gas Humidification during Mechanical Ventilation in Dogs

PubMed Central

Hernández-Jiménez, Claudia; García-Torrentera, Rogelio; Olmos-Zúñiga, J. Raúl; Jasso-Victoria, Rogelio; Gaxiola-Gaxiola, Miguel O.; Baltazares-Lipp, Matilde; Gutiérrez-González, Luis H.

2014-01-01

The use of dry gases during mechanical ventilation has been associated with the risk of serious airway complications. The goal of the present study was to quantify the plasma levels of TNF-alpha and IL-6 and to determine the radiological, hemodynamic, gasometric, and microscopic changes in lung mechanics in dogs subjected to short-term mechanical ventilation with and without humidification of the inhaled gas. The experiment was conducted for 24 hours in 10 dogs divided into two groups: Group I (n = 5), mechanical ventilation with dry oxygen dispensation, and Group II (n = 5), mechanical ventilation with oxygen dispensation using a moisture chamber. Variance analysis was used. No changes in physiological, hemodynamic, or gasometric, and radiographic constants were observed. Plasma TNF-alpha levels increased in group I, reaching a maximum 24 hours after mechanical ventilation was initiated (ANOVA p = 0.77). This increase was correlated to changes in mechanical ventilation. Plasma IL-6 levels decreased at 12 hours and increased again towards the end of the study (ANOVA p>0.05). Both groups exhibited a decrease in lung compliance and functional residual capacity values, but this was more pronounced in group I. Pplat increased in group I (ANOVA p = 0.02). Inhalation of dry gas caused histological lesions in the entire respiratory tract, including pulmonary parenchyma, to a greater extent than humidified gas. Humidification of inspired gases can attenuate damage associated with mechanical ventilation. PMID:25036811

Respiratory mechanics and plasma levels of tumor necrosis factor alpha and interleukin 6 are affected by gas humidification during mechanical ventilation in dogs.

PubMed

Hernández-Jiménez, Claudia; García-Torrentera, Rogelio; Olmos-Zúñiga, J Raúl; Jasso-Victoria, Rogelio; Gaxiola-Gaxiola, Miguel O; Baltazares-Lipp, Matilde; Gutiérrez-González, Luis H

2014-01-01

The use of dry gases during mechanical ventilation has been associated with the risk of serious airway complications. The goal of the present study was to quantify the plasma levels of TNF-alpha and IL-6 and to determine the radiological, hemodynamic, gasometric, and microscopic changes in lung mechanics in dogs subjected to short-term mechanical ventilation with and without humidification of the inhaled gas. The experiment was conducted for 24 hours in 10 dogs divided into two groups: Group I (n = 5), mechanical ventilation with dry oxygen dispensation, and Group II (n = 5), mechanical ventilation with oxygen dispensation using a moisture chamber. Variance analysis was used. No changes in physiological, hemodynamic, or gasometric, and radiographic constants were observed. Plasma TNF-alpha levels increased in group I, reaching a maximum 24 hours after mechanical ventilation was initiated (ANOVA p = 0.77). This increase was correlated to changes in mechanical ventilation. Plasma IL-6 levels decreased at 12 hours and increased again towards the end of the study (ANOVA p>0.05). Both groups exhibited a decrease in lung compliance and functional residual capacity values, but this was more pronounced in group I. Pplat increased in group I (ANOVA p = 0.02). Inhalation of dry gas caused histological lesions in the entire respiratory tract, including pulmonary parenchyma, to a greater extent than humidified gas. Humidification of inspired gases can attenuate damage associated with mechanical ventilation.

Comparison between conventional protective mechanical ventilation and high-frequency oscillatory ventilation associated with the prone position.

PubMed

Fioretto, José Roberto; Klefens, Susiane Oliveira; Pires, Rafaelle Fernandes; Kurokawa, Cilmery Suemi; Carpi, Mario Ferreira; Bonatto, Rossano César; Moraes, Marcos Aurélio; Ronchi, Carlos Fernando

2017-01-01

To compare the effects of high-frequency oscillatory ventilation and conventional protective mechanical ventilation associated with the prone position on oxygenation, histology and pulmonary oxidative damage in an experimental model of acute lung injury. Forty-five rabbits with tracheostomy and vascular access were underwent mechanical ventilation. Acute lung injury was induced by tracheal infusion of warm saline. Three experimental groups were formed: healthy animals + conventional protective mechanical ventilation, supine position (Control Group; n = 15); animals with acute lung injury + conventional protective mechanical ventilation, prone position (CMVG; n = 15); and animals with acute lung injury + high-frequency oscillatory ventilation, prone position (HFOG; n = 15). Ten minutes after the beginning of the specific ventilation of each group, arterial gasometry was collected, with this timepoint being called time zero, after which the animal was placed in prone position and remained in this position for 4 hours. Oxidative stress was evaluated by the total antioxidant performance assay. Pulmonary tissue injury was determined by histopathological score. The level of significance was 5%. Both groups with acute lung injury showed worsening of oxygenation after induction of injury compared with the Control Group. After 4 hours, there was a significant improvement in oxygenation in the HFOG group compared with CMVG. Analysis of total antioxidant performance in plasma showed greater protection in HFOG. HFOG had a lower histopathological lesion score in lung tissue than CMVG. High-frequency oscillatory ventilation, associated with prone position, improves oxygenation and attenuates oxidative damage and histopathological lung injury compared with conventional protective mechanical ventilation.

Comparison between conventional protective mechanical ventilation and high-frequency oscillatory ventilation associated with the prone position

PubMed Central

Fioretto, José Roberto; Klefens, Susiane Oliveira; Pires, Rafaelle Fernandes; Kurokawa, Cilmery Suemi; Carpi, Mario Ferreira; Bonatto, Rossano César; Moraes, Marcos Aurélio; Ronchi, Carlos Fernando

2017-01-01

Objective To compare the effects of high-frequency oscillatory ventilation and conventional protective mechanical ventilation associated with the prone position on oxygenation, histology and pulmonary oxidative damage in an experimental model of acute lung injury. Methods Forty-five rabbits with tracheostomy and vascular access were underwent mechanical ventilation. Acute lung injury was induced by tracheal infusion of warm saline. Three experimental groups were formed: healthy animals + conventional protective mechanical ventilation, supine position (Control Group; n = 15); animals with acute lung injury + conventional protective mechanical ventilation, prone position (CMVG; n = 15); and animals with acute lung injury + high-frequency oscillatory ventilation, prone position (HFOG; n = 15). Ten minutes after the beginning of the specific ventilation of each group, arterial gasometry was collected, with this timepoint being called time zero, after which the animal was placed in prone position and remained in this position for 4 hours. Oxidative stress was evaluated by the total antioxidant performance assay. Pulmonary tissue injury was determined by histopathological score. The level of significance was 5%. Results Both groups with acute lung injury showed worsening of oxygenation after induction of injury compared with the Control Group. After 4 hours, there was a significant improvement in oxygenation in the HFOG group compared with CMVG. Analysis of total antioxidant performance in plasma showed greater protection in HFOG. HFOG had a lower histopathological lesion score in lung tissue than CMVG. Conclusion High-frequency oscillatory ventilation, associated with prone position, improves oxygenation and attenuates oxidative damage and histopathological lung injury compared with conventional protective mechanical ventilation. PMID:29236845

Parameter selection for and implementation of a web-based decision-support tool to predict extubation outcome in premature infants.

PubMed

Mueller, Martina; Wagner, Carol L; Annibale, David J; Knapp, Rebecca G; Hulsey, Thomas C; Almeida, Jonas S

2006-03-01

Approximately 30% of intubated preterm infants with respiratory distress syndrome (RDS) will fail attempted extubation, requiring reintubation and mechanical ventilation. Although ventilator technology and monitoring of premature infants have improved over time, optimal extubation remains challenging. Furthermore, extubation decisions for premature infants require complex informational processing, techniques implicitly learned through clinical practice. Computer-aided decision-support tools would benefit inexperienced clinicians, especially during peak neonatal intensive care unit (NICU) census. A five-step procedure was developed to identify predictive variables. Clinical expert (CE) thought processes comprised one model. Variables from that model were used to develop two mathematical models for the decision-support tool: an artificial neural network (ANN) and a multivariate logistic regression model (MLR). The ranking of the variables in the three models was compared using the Wilcoxon Signed Rank Test. The best performing model was used in a web-based decision-support tool with a user interface implemented in Hypertext Markup Language (HTML) and the mathematical model employing the ANN. CEs identified 51 potentially predictive variables for extubation decisions for an infant on mechanical ventilation. Comparisons of the three models showed a significant difference between the ANN and the CE (p = 0.0006). Of the original 51 potentially predictive variables, the 13 most predictive variables were used to develop an ANN as a web-based decision-tool. The ANN processes user-provided data and returns the prediction 0-1 score and a novelty index. The user then selects the most appropriate threshold for categorizing the prediction as a success or failure. Furthermore, the novelty index, indicating the similarity of the test case to the training case, allows the user to assess the confidence level of the prediction with regard to how much the new data differ from the data originally used for the development of the prediction tool. State-of-the-art, machine-learning methods can be employed for the development of sophisticated tools to aid clinicians' decisions. We identified numerous variables considered relevant for extubation decisions for mechanically ventilated premature infants with RDS. We then developed a web-based decision-support tool for clinicians which can be made widely available and potentially improve patient care world wide.

Mechanical ventilation interacts with endotoxemia to induce extrapulmonary organ dysfunction

PubMed Central

O'Mahony, D Shane; Liles, W Conrad; Altemeier, William A; Dhanireddy, Shireesha; Frevert, Charles W; Liggitt, Denny; Martin, Thomas R; Matute-Bello, Gustavo

2006-01-01

Introduction Multiple organ dysfunction syndrome (MODS) is a common complication of sepsis in mechanically ventilated patients with acute respiratory distress syndrome, but the links between mechanical ventilation and MODS are unclear. Our goal was to determine whether a minimally injurious mechanical ventilation strategy synergizes with low-dose endotoxemia to induce the activation of pro-inflammatory pathways in the lungs and in the systemic circulation, resulting in distal organ dysfunction and/or injury. Methods We administered intraperitoneal Escherichia coli lipopolysaccharide (LPS; 1 μg/g) to C57BL/6 mice, and 14 hours later subjected the mice to 6 hours of mechanical ventilation with tidal volumes of 10 ml/kg (LPS + MV). Comparison groups received ventilation but no LPS (MV), LPS but no ventilation (LPS), or neither LPS nor ventilation (phosphate-buffered saline; PBS). Results Myeloperoxidase activity and the concentrations of the chemokines macrophage inflammatory protein-2 (MIP-2) and KC were significantly increased in the lungs of mice in the LPS + MV group, in comparison with mice in the PBS group. Interestingly, permeability changes across the alveolar epithelium and histological changes suggestive of lung injury were minimal in mice in the LPS + MV group. However, despite the minimal lung injury, the combination of mechanical ventilation and LPS resulted in chemical and histological evidence of liver and kidney injury, and this was associated with increases in the plasma concentrations of KC, MIP-2, IL-6, and TNF-α. Conclusion Non-injurious mechanical ventilation strategies interact with endotoxemia in mice to enhance pro-inflammatory mechanisms in the lungs and promote extra-pulmonary end-organ injury, even in the absence of demonstrable acute lung injury. PMID:16995930

Ventilation-induced increases in EGFR ligand mRNA are not altered by intra-amniotic LPS or ureaplasma in preterm lambs.

PubMed

Hillman, Noah H; Gisslen, Tate; Polglase, Graeme R; Kallapur, Suhas G; Jobe, Alan H

2014-01-01

Chorioamnionitis and mechanical ventilation are associated with bronchopulmonary dysplasia (BPD) in preterm infants. Mechanical ventilation at birth activates both inflammatory and acute phase responses. These responses can be partially modulated by previous exposure to intra-amniotic (IA) LPS or Ureaplasma parvum (UP). Epidermal growth factor receptor (EGFR) ligands participate in lung development, and angiotensin converting enzyme (ACE) 1 and ACE2 contribute to lung inflammation. We asked whether brief mechanical ventilation at birth altered EGFR and ACE pathways and if antenatal exposure to IA LPS or UP could modulate these effects. Ewes were exposed to IA injections of UP, LPS or saline multiple days prior to preterm delivery at 85% gestation. Lambs were either immediately euthanized or mechanically ventilated for 2 to 3 hr. IA UP and LPS cause modest changes in the EGFR ligands amphiregulin (AREG), epiregulin (EREG), heparin binding epidermal growth factor (HB-EGF), and betacellulin (BTC) mRNA expression. Mechanical ventilation greatly increased mRNA expression of AREG, EREG, and HB-EGF, with no additional increases resulting from IA LPS or UP. With ventilation AREG and EREG mRNA localized to cells in terminal airspace. EGFR mRNA also increased with mechanical ventilation. IA UP and LPS decreased ACE1 mRNA and increased ACE2 mRNA, resulting in a 4 fold change in the ACE1/ACE2 ratio. Mechanical ventilation with large tidal volumes increased both ACE1 and ACE2 expression. The alterations seen in ACE with IA exposures and EGFR pathways with mechanical ventilation may contribute to the development of BPD in preterm infants.

[Non-invasive mechanical ventilation in the pre- and intraoperative period and difficult airway].

PubMed

Esquinas, A M; Jover, J L; Úbeda, A; Belda, F J

2015-11-01

Non-invasive mechanical ventilation is a method of ventilatory assistance aimed at increasing alveolar ventilation, thus achieving, in selected subjects, the avoidance of endotracheal intubation and invasive mechanical ventilation, with the consequent improvement in survival. There has been a systematic review and study of the technical, clinical experiences, and recommendations concerning the application of non-invasive mechanical ventilation in the pre- and intraoperative period. The use of prophylactic non-invasive mechanical ventilation before surgery that involves significant alterations in the ventilatory function may decrease the incidence of postoperative respiratory complications. Its intraoperative use will mainly depend on the type of surgery, type of anaesthetic technique, and the clinical status of the patient. Its use allows greater anaesthetic depth without deterioration of oxygenation and ventilation of patients. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Effects of positive end-expiratory pressure on intracranial pressure in mechanically ventilated dogs under hyperbaric oxygenation.

PubMed

Sun, Qing; Wu, Di; Yu, Tao; Yang, Ying; Wei, Li; Lv, Fuxiang; Gao, Guangkai

2014-01-01

Mechanical ventilation with positive end-expiratory pressure (PEEP) has been advocated as an essential life support for critical patients. However, its side effect, which is demonstrated by an elevation of intracranial pressure (ICP) under normobaric (NBO2) conditions, is potentially detrimental to patients. Hyperbaric oxygen (HBO2) therapy, on the other hand, is frequently applied for the same group of patients, and its efficacy is shown by maintaining a higher PaO2 and a reduced ICP. Our study investigated the effect of HBO2 and NBO2 on ICP with or without PEEP ventilation on healthy dogs by comparing cerebrospinal fluid pressure (CSFP) and concluded that the elevation of PEEP resulted in a significant increase of ICP (CSFP) under both conditions (p < 0.05). HBO2 leads to a lower ICP increase compared to the NBO2 group. Under the same level of PEEP, the joint use of PEEP and HBO2 is safe and highly practical in clinical medicine.

Humidification during invasive and noninvasive mechanical ventilation: 2012.

PubMed

Restrepo, Ruben D; Walsh, Brian K

2012-05-01

We searched the MEDLINE, CINAHL, and Cochrane Library databases for articles published between January 1990 and December 2011. The update of this clinical practice guideline is based on 184 clinical trials and systematic reviews, and 10 articles investigating humidification during invasive and noninvasive mechanical ventilation. The following recommendations are made following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) scoring system: 1. Humidification is recommended on every patient receiving invasive mechanical ventilation. 2. Active humidification is suggested for noninvasive mechanical ventilation, as it may improve adherence and comfort. 3. When providing active humidification to patients who are invasively ventilated, it is suggested that the device provide a humidity level between 33 mg H(2)O/L and 44 mg H(2)O/L and gas temperature between 34°C and 41°C at the circuit Y-piece, with a relative humidity of 100%. 4. When providing passive humidification to patients undergoing invasive mechanical ventilation, it is suggested that the HME provide a minimum of 30 mg H(2)O/L. 5. Passive humidification is not recommended for noninvasive mechanical ventilation. 6. When providing humidification to patients with low tidal volumes, such as when lung-protective ventilation strategies are used, HMEs are not recommended because they contribute additional dead space, which can increase the ventilation requirement and P(aCO(2)). 7. It is suggested that HMEs are not used as a prevention strategy for ventilator-associated pneumonia.

Variable tidal volumes improve lung protective ventilation strategies in experimental lung injury.

PubMed

Spieth, Peter M; Carvalho, Alysson R; Pelosi, Paolo; Hoehn, Catharina; Meissner, Christoph; Kasper, Michael; Hübler, Matthias; von Neindorff, Matthias; Dassow, Constanze; Barrenschee, Martina; Uhlig, Stefan; Koch, Thea; de Abreu, Marcelo Gama

2009-04-15

Noisy ventilation with variable Vt may improve respiratory function in acute lung injury. To determine the impact of noisy ventilation on respiratory function and its biological effects on lung parenchyma compared with conventional protective mechanical ventilation strategies. In a porcine surfactant depletion model of lung injury, we randomly combined noisy ventilation with the ARDS Network protocol or the open lung approach (n = 9 per group). Respiratory mechanics, gas exchange, and distribution of pulmonary blood flow were measured at intervals over a 6-hour period. Postmortem, lung tissue was analyzed to determine histological damage, mechanical stress, and inflammation. We found that, at comparable minute ventilation, noisy ventilation (1) improved arterial oxygenation and reduced mean inspiratory peak airway pressure and elastance of the respiratory system compared with the ARDS Network protocol and the open lung approach, (2) redistributed pulmonary blood flow to caudal zones compared with the ARDS Network protocol and to peripheral ones compared with the open lung approach, (3) reduced histological damage in comparison to both protective ventilation strategies, and (4) did not increase lung inflammation or mechanical stress. Noisy ventilation with variable Vt and fixed respiratory frequency improves respiratory function and reduces histological damage compared with standard protective ventilation strategies.

A randomized clinical trial comparing an extended-use hygroscopic condenser humidifier with heated-water humidification in mechanically ventilated patients.

PubMed

Kollef, M H; Shapiro, S D; Boyd, V; Silver, P; Von Harz, B; Trovillion, E; Prentice, D

1998-03-01

To determine the safety and cost-effectiveness of mechanical ventilation with an extended-use hygroscopic condenser humidifier (Duration; Nellcor Puritan-Bennett; Eden Prairie, Minn) compared with mechanical ventilation with heated-water humidification. Prospective randomized clinical trial. Medical and surgical ICUs of Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital. Three hundred ten consecutive qualified patients undergoing mechanical ventilation. Patients requiring mechanical ventilation were randomly assigned to receive humidification with either an extended-use hygroscopic condenser humidifier (for up to the first 7 days of mechanical ventilation) or heated-water humidification. Occurrence of ventilator-associated pneumonia, endotracheal tube occlusion, duration of mechanical ventilation, lengths of intensive care and hospitalization, acquired multiorgan dysfunction, and hospital mortality. One hundred sixty-three patients were randomly assigned to receive humidification with an extended-use hygroscopic condenser humidifier, and 147 patients were randomly assigned to receive heated-water humidification. The two groups were similar at the time of randomization with regard to demographic characteristics, ICU admission diagnoses, and severity of illness. Risk factors for the development of ventilator-associated pneumonia were also similar during the study period for both treatment groups. Ventilator-associated pneumonia was seen in 15 (9.2%) patients receiving humidification with an extended-use hygroscopic condenser humidifier and in 15 (10.2%) patients receiving heated-water humidification (relative risk, 0.90; 95% confidence interval=0.46 to 1.78; p=0.766). No statistically significant differences for hospital mortality, duration of mechanical ventilation, lengths of stay in the hospital ICU, or acquired organ system derangements were found between the two treatment groups. No episode of endotracheal tube occlusion occurred during the study period in either treatment group. The total cost of providing humidification was $2,605 for patients receiving a hygroscopic condenser humidifier compared with $5,625 for patients receiving heated-water humidification. Our findings suggest that the initial application of an extended-use hygroscopic condenser humidifier is a safe and more cost-effective method of providing humidification to patients requiring mechanical ventilation compared with heated-water humidification.

Particle size concentration distribution and influences on exhaled breath particles in mechanically ventilated patients.

PubMed

Wan, Gwo-Hwa; Wu, Chieh-Liang; Chen, Yi-Fang; Huang, Sheng-Hsiu; Wang, Yu-Ling; Chen, Chun-Wan

2014-01-01

Humans produce exhaled breath particles (EBPs) during various breath activities, such as normal breathing, coughing, talking, and sneezing. Airborne transmission risk exists when EBPs have attached pathogens. Until recently, few investigations had evaluated the size and concentration distributions of EBPs from mechanically ventilated patients with different ventilation mode settings. This study thus broke new ground by not only evaluating the size concentration distributions of EBPs in mechanically ventilated patients, but also investigating the relationship between EBP level and positive expiratory end airway pressure (PEEP), tidal volume, and pneumonia. This investigation recruited mechanically ventilated patients, with and without pneumonia, aged 20 years old and above, from the respiratory intensive care unit of a medical center. Concentration distributions of EBPs from mechanically ventilated patients were analyzed with an optical particle analyzer. This study finds that EBP concentrations from mechanically ventilated patients during normal breathing were in the range 0.47-2,554.04 particles/breath (0.001-4.644 particles/mL). EBP concentrations did not differ significantly between the volume control and pressure control modes of the ventilation settings in the mechanically ventilated patients. The patient EBPs were sized below 5 µm, and 80% of them ranged from 0.3 to 1.0 µm. The EBPs concentrations in patients with high PEEP (> 5 cmH₂O) clearly exceeded those in patients with low PEEP (≤ 5 cmH₂O). Additionally, a significant negative association existed between pneumonia duration and EBPs concentration. However, tidal volume was not related to EBPs concentration.

An experimental study on the impacts of inspiratory and expiratory muscles activities during mechanical ventilation in ARDS animal model

PubMed Central

Zhang, Xianming; Du, Juan; Wu, Weiliang; Zhu, Yongcheng; Jiang, Ying; Chen, Rongchang

2017-01-01

In spite of intensive investigations, the role of spontaneous breathing (SB) activity in ARDS has not been well defined yet and little has been known about the different contribution of inspiratory or expiratory muscles activities during mechanical ventilation in patients with ARDS. In present study, oleic acid-induced beagle dogs’ ARDS models were employed and ventilated with the same level of mean airway pressure. Respiratory mechanics, lung volume, gas exchange and inflammatory cytokines were measured during mechanical ventilation, and lung injury was determined histologically. As a result, for the comparable ventilator setting, preserved inspiratory muscles activity groups resulted in higher end-expiratory lung volume (EELV) and oxygenation index. In addition, less lung damage scores and lower levels of system inflammatory cytokines were revealed after 8 h of ventilation. In comparison, preserved expiratory muscles activity groups resulted in lower EELV and oxygenation index. Moreover, higher lung injury scores and inflammatory cytokines levels were observed after 8 h of ventilation. Our findings suggest that the activity of inspiratory muscles has beneficial effects, whereas that of expiratory muscles exerts adverse effects during mechanical ventilation in ARDS animal model. Therefore, for mechanically ventilated patients with ARDS, the demands for deep sedation or paralysis might be replaced by the strategy of expiratory muscles paralysis through epidural anesthesia. PMID:28230150

[Oxidative stress in patients on mechanical ventilation].

PubMed

Marjanović, Vesna; Dordević, Vidosava; Marjanović, Goran

2009-01-01

The appearance and intensity of oxidative stress were analyzed in the course of mechanical ventilation and parameters that could point toward potential lung damage. In three time intervals on day 1, 3 and 7 of mechanical ventilation, parameters such as: triglycerides, cholesterol, lactate, serum lactic dehydrogenase, acid-base balance and lipid peroxidation products--thiobarbituric acid reactive substances, were followed in 30 patients with head injuries. A decrease in the level of partial oxygen pressure (PaO2) (p < 0.01) and PaO2/FiO2 index (p < 0.05) in arterial blood was recorded on day 3 of mechanical ventilation. This was accompanied with an increase in alveolar-arterial difference (AaDO2) (p < 0.05), thiobarbituric acid reactive substances (p < 0.001) and lactic dehydrogenase (p < 0.001) comparing to day 1 of mechanical ventilation. The patients with initial PaO2 > 120 mmHg, had significant increase of thiobarbituric acid reactive substances and AaDO2 (p < 0.05) and fall of PaO2 (p < 0.001) on day 3 of mechanical ventilation. Oxidative stress and lipid peroxide production are increased during third day of mechanical ventilation leading to disruption of oxygen diffusion through alveolar-capillary membrane and reduction of parameters of oxygenation.

Education on invasive mechanical ventilation involving intensive care nurses: a systematic review.

PubMed

Guilhermino, Michelle C; Inder, Kerry J; Sundin, Deborah

2018-03-26

Intensive care unit nurses are critical for managing mechanical ventilation. Continuing education is essential in building and maintaining nurses' knowledge and skills, potentially improving patient outcomes. The aim of this study was to determine whether continuing education programmes on invasive mechanical ventilation involving intensive care unit nurses are effective in improving patient outcomes. Five electronic databases were searched from 2001 to 2016 using keywords such as mechanical ventilation, nursing and education. Inclusion criteria were invasive mechanical ventilation continuing education programmes that involved nurses and measured patient outcomes. Primary outcomes were intensive care unit mortality and in-hospital mortality. Secondary outcomes included hospital and intensive care unit length of stay, length of intubation, failed weaning trials, re-intubation incidence, ventilation-associated pneumonia rate and lung-protective ventilator strategies. Studies were excluded if they excluded nurses, patients were ventilated for less than 24 h, the education content focused on protocol implementation or oral care exclusively or the outcomes were participant satisfaction. Quality was assessed by two reviewers using an education intervention critical appraisal worksheet and a risk of bias assessment tool. Data were extracted independently by two reviewers and analysed narratively due to heterogeneity. Twelve studies met the inclusion criteria for full review: 11 pre- and post-intervention observational and 1 quasi-experimental design. Studies reported statistically significant reductions in hospital length of stay, length of intubation, ventilator-associated pneumonia rates, failed weaning trials and improvements in lung-protective ventilation compliance. Non-statistically significant results were reported for in-hospital and intensive care unit mortality, re-intubation and intensive care unit length of stay. Limited evidence of the effectiveness of continuing education programmes on mechanical ventilation involving nurses in improving patient outcomes exists. Comprehensive continuing education is required. Well-designed trials are required to confirm that comprehensive continuing education involving intensive care nurses about mechanical ventilation improves patient outcomes. © 2018 British Association of Critical Care Nurses.

Our great forgotten, chronic respiratory sufferers

PubMed

Bordejé Laguna, María Luisa

2017-05-08

Lung’s own properties make that nutritional support, besides covering the requirements can modulate its infl ammatory response. Lung tissue has a low glucose stock. Fatty acids are the main energy producer of type II pneumocytes, which use them in order to form phospholipids, essential for surfactant whose creation and release decrease in acute lung injury (ALI). Glutamine is a good substratum for endocrine cells and type II pneumocytes. Due to high nutritional risk, it is important its assessments in disorders as COPD and acute respiratory distress syndrome (ADRS). Indirect calorimetry values the effect of ventilation and nutritional support, avoiding overfeeding. Hypophosphatemia and refeeding syndrome are frequent and need to be avoided because of their morbidity. In critically ill patients, malnutrition can lead to respiratory failure and increasing mechanical ventilation time. To avoid hypercapnia in weaning, glucose levels should be controlled. High lipids/carbohydrates ratio do not show usefulness in COPD neither mechanical ventilation removal. ALI patients beneficiate from an early start and the volume administered. Enteral nutrition with high fatty acids ratio (EPA, DHA and γ-linolenic acid) and antioxidants do not show any superiority. Omega-3 fatty acid in parenteral nutrition could modulate infl ammation and immunosuppression in a positive manner. The use of glutamine, vitamins or antioxidants in these patients could be justified.

Spatiotemporal Aeration and Lung Injury Patterns Are Influenced by the First Inflation Strategy at Birth.

PubMed

Tingay, David G; Rajapaksa, Anushi; Zonneveld, C Elroy; Black, Don; Perkins, Elizabeth J; Adler, Andy; Grychtol, Bartłomiej; Lavizzari, Anna; Frerichs, Inéz; Zahra, Valerie A; Davis, Peter G

2016-02-01

Ineffective aeration during the first inflations at birth creates regional aeration and ventilation defects, initiating injurious pathways. This study aimed to compare a sustained first inflation at birth or dynamic end-expiratory supported recruitment during tidal inflations against ventilation without intentional recruitment on gas exchange, lung mechanics, spatiotemporal regional aeration and tidal ventilation, and regional lung injury in preterm lambs. Lambs (127 ± 2 d gestation), instrumented at birth, were ventilated for 60 minutes from birth with either lung-protective positive pressure ventilation (control) or as per control after either an initial 30 seconds of 40 cm H2O sustained inflation (SI) or an initial stepwise end-expiratory pressure recruitment maneuver during tidal inflations (duration 180 s; open lung ventilation [OLV]). At study completion, molecular markers of lung injury were analyzed. The initial use of an OLV maneuver, but not SI, at birth resulted in improved lung compliance, oxygenation, end-expiratory lung volume, and reduced ventilatory needs compared with control, persisting throughout the study. These changes were due to more uniform inter- and intrasubject gravity-dependent spatiotemporal patterns of aeration (measured using electrical impedance tomography). Spatial distribution of tidal ventilation was more stable after either recruitment maneuver. All strategies caused regional lung injury patterns that mirrored associated regional volume states. Irrespective of strategy, spatiotemporal volume loss was consistently associated with up-regulation of early growth response-1 expression. Our results show that mechanical and molecular consequences of lung aeration at birth are not simply related to rapidity of fluid clearance; they are also related to spatiotemporal pressure-volume interactions within the lung during inflation and deflation.

Brain caspase-3 and intestinal FABP responses in preterm and term rats submitted to birth asphyxia.

PubMed

Figueira, R L; Gonçalves, F L; Simões, A L; Bernardino, C A; Lopes, L S; Castro E Silva, O; Sbragia, L

2016-06-23

Neonatal asphyxia can cause irreversible injury of multiple organs resulting in hypoxic-ischemic encephalopathy and necrotizing enterocolitis (NEC). This injury is dependent on time, severity, and gestational age, once the preterm babies need ventilator support. Our aim was to assess the different brain and intestinal effects of ischemia and reperfusion in neonate rats after birth anoxia and mechanical ventilation. Preterm and term neonates were divided into 8 subgroups (n=12/group): 1) preterm control (PTC), 2) preterm ventilated (PTV), 3) preterm asphyxiated (PTA), 4) preterm asphyxiated and ventilated (PTAV), 5) term control (TC), 6) term ventilated (TV), 7) term asphyxiated (TA), and 8) term asphyxiated and ventilated (TAV). We measured body, brain, and intestine weights and respective ratios [(BW), (BrW), (IW), (BrW/BW) and (IW/BW)]. Histology analysis and damage grading were performed in the brain (cortex/hippocampus) and intestine (jejunum/ileum) tissues, as well as immunohistochemistry analysis for caspase-3 and intestinal fatty acid-binding protein (I-FABP). IW was lower in the TA than in the other terms (P<0.05), and the IW/BW ratio was lower in the TA than in the TAV (P<0.005). PTA, PTAV and TA presented high levels of brain damage. In histological intestinal analysis, PTAV and TAV had higher scores than the other groups. Caspase-3 was higher in PTAV (cortex) and TA (cortex/hippocampus) (P<0.005). I-FABP was higher in PTAV (P<0.005) and TA (ileum) (P<0.05). I-FABP expression was increased in PTAV subgroup (P<0.0001). Brain and intestinal responses in neonatal rats caused by neonatal asphyxia, with or without mechanical ventilation, varied with gestational age, with increased expression of caspase-3 and I-FABP biomarkers.

Brain caspase-3 and intestinal FABP responses in preterm and term rats submitted to birth asphyxia

PubMed Central

Figueira, R.L.; Gonçalves, F.L.; Simões, A.L.; Bernardino, C.A.; Lopes, L.S.; Castro e Silva, O.; Sbragia, L.

2016-01-01

Neonatal asphyxia can cause irreversible injury of multiple organs resulting in hypoxic-ischemic encephalopathy and necrotizing enterocolitis (NEC). This injury is dependent on time, severity, and gestational age, once the preterm babies need ventilator support. Our aim was to assess the different brain and intestinal effects of ischemia and reperfusion in neonate rats after birth anoxia and mechanical ventilation. Preterm and term neonates were divided into 8 subgroups (n=12/group): 1) preterm control (PTC), 2) preterm ventilated (PTV), 3) preterm asphyxiated (PTA), 4) preterm asphyxiated and ventilated (PTAV), 5) term control (TC), 6) term ventilated (TV), 7) term asphyxiated (TA), and 8) term asphyxiated and ventilated (TAV). We measured body, brain, and intestine weights and respective ratios [(BW), (BrW), (IW), (BrW/BW) and (IW/BW)]. Histology analysis and damage grading were performed in the brain (cortex/hippocampus) and intestine (jejunum/ileum) tissues, as well as immunohistochemistry analysis for caspase-3 and intestinal fatty acid-binding protein (I-FABP). IW was lower in the TA than in the other terms (P<0.05), and the IW/BW ratio was lower in the TA than in the TAV (P<0.005). PTA, PTAV and TA presented high levels of brain damage. In histological intestinal analysis, PTAV and TAV had higher scores than the other groups. Caspase-3 was higher in PTAV (cortex) and TA (cortex/hippocampus) (P<0.005). I-FABP was higher in PTAV (P<0.005) and TA (ileum) (P<0.05). I-FABP expression was increased in PTAV subgroup (P<0.0001). Brain and intestinal responses in neonatal rats caused by neonatal asphyxia, with or without mechanical ventilation, varied with gestational age, with increased expression of caspase-3 and I-FABP biomarkers. PMID:27356106

Glutamate receptors in the nucleus tractus solitarius contribute to ventilatory acclimatization to hypoxia in rat

PubMed Central

Pamenter, Matthew E; Carr, J Austin; Go, Ariel; Fu, Zhenxing; Reid, Stephen G; Powell, Frank L

2014-01-01

When exposed to a hypoxic environment the body's first response is a reflex increase in ventilation, termed the hypoxic ventilatory response (HVR). With chronic sustained hypoxia (CSH), such as during acclimatization to high altitude, an additional time-dependent increase in ventilation occurs, which increases the HVR. This secondary increase persists after exposure to CSH and involves plasticity within the circuits in the central nervous system that control breathing. Currently these mechanisms of HVR plasticity are unknown and we hypothesized that they involve glutamatergic synapses in the nucleus tractus solitarius (NTS), where afferent endings from arterial chemoreceptors terminate. To test this, we treated rats held in normoxia (CON) or 10% O2 (CSH) for 7 days and measured ventilation in conscious, unrestrained animals before and after microinjecting glutamate receptor agonists and antagonists into the NTS. In normoxia, AMPA increased ventilation 25% and 50% in CON and CSH, respectively, while NMDA doubled ventilation in both groups (P < 0.05). Specific AMPA and NMDA receptor antagonists (NBQX and MK801, respectively) abolished these effects. MK801 significantly decreased the HVR in CON rats, and completely blocked the acute HVR in CSH rats but had no effect on ventilation in normoxia. NBQX decreased ventilation whenever it was increased relative to normoxic controls; i.e. acute hypoxia in CON and CSH, and normoxia in CSH. These results support our hypothesis that glutamate receptors in the NTS contribute to plasticity in the HVR with CSH. The mechanism underlying this synaptic plasticity is probably glutamate receptor modification, as in CSH rats the expression of phosphorylated NR1 and GluR1 proteins in the NTS increased 35% and 70%, respectively, relative to that in CON rats. PMID:24492841

Glutamate receptors in the nucleus tractus solitarius contribute to ventilatory acclimatization to hypoxia in rat.

PubMed

Pamenter, Matthew E; Carr, J Austin; Go, Ariel; Fu, Zhenxing; Reid, Stephen G; Powell, Frank L

2014-04-15

When exposed to a hypoxic environment the body's first response is a reflex increase in ventilation, termed the hypoxic ventilatory response (HVR). With chronic sustained hypoxia (CSH), such as during acclimatization to high altitude, an additional time-dependent increase in ventilation occurs, which increases the HVR. This secondary increase persists after exposure to CSH and involves plasticity within the circuits in the central nervous system that control breathing. Currently these mechanisms of HVR plasticity are unknown and we hypothesized that they involve glutamatergic synapses in the nucleus tractus solitarius (NTS), where afferent endings from arterial chemoreceptors terminate. To test this, we treated rats held in normoxia (CON) or 10% O2 (CSH) for 7 days and measured ventilation in conscious, unrestrained animals before and after microinjecting glutamate receptor agonists and antagonists into the NTS. In normoxia, AMPA increased ventilation 25% and 50% in CON and CSH, respectively, while NMDA doubled ventilation in both groups (P < 0.05). Specific AMPA and NMDA receptor antagonists (NBQX and MK801, respectively) abolished these effects. MK801 significantly decreased the HVR in CON rats, and completely blocked the acute HVR in CSH rats but had no effect on ventilation in normoxia. NBQX decreased ventilation whenever it was increased relative to normoxic controls; i.e. acute hypoxia in CON and CSH, and normoxia in CSH. These results support our hypothesis that glutamate receptors in the NTS contribute to plasticity in the HVR with CSH. The mechanism underlying this synaptic plasticity is probably glutamate receptor modification, as in CSH rats the expression of phosphorylated NR1 and GluR1 proteins in the NTS increased 35% and 70%, respectively, relative to that in CON rats.

Personalizing mechanical ventilation for acute respiratory distress syndrome.

PubMed

Berngard, S Clark; Beitler, Jeremy R; Malhotra, Atul

2016-03-01

Lung-protective ventilation with low tidal volumes remains the cornerstone for treating patient with acute respiratory distress syndrome (ARDS). Personalizing such an approach to each patient's unique physiology may improve outcomes further. Many factors should be considered when mechanically ventilating a critically ill patient with ARDS. Estimations of transpulmonary pressures as well as individual's hemodynamics and respiratory mechanics should influence PEEP decisions as well as response to therapy (recruitability). This summary will emphasize the potential role of personalized therapy in mechanical ventilation.

Outcomes management of mechanically ventilated patients: utilizing informatics technology.

PubMed

Smith, K R

1998-11-01

This article examines an informatics system developed for outcomes management of the mechanically ventilated adult population, focusing on weaning the patient from mechanical ventilation. The link between medical informatics and outcomes management is discussed, along with the development of methods, tools, and data sets for outcomes management of the mechanically ventilated adult population at an acute care academic institution. Pros and cons of this system are identified, and specific areas for improvement of future health care outcomes medical informatics systems are discussed.

Prone versus supine position in mechanically ventilated children: a pilot study.

PubMed

Sawhney, Ashu; Kumar, Nirmal; Sreenivas, Vishnubhatla; Gupta, Sangeeta; Tyagi, Vineet; Puliyel, Jacob M

2005-05-01

It is known that mechanically ventilated patients in the prone position have improved oxygenation compared with those supine. We did a prospective, randomized, controlled trial to evaluate the effect of prone position during mechanical ventilation, on survival in critically ill children. Forty-two children needing mechanical ventilation for various illnesses were randomized to receive initial ventilation for four hours prone or supine by drawing lots. Initial severity of illness and blood gases in all children were noted. In a crossover design, after the initial four hours the children were turned over and ventilated in the alternate posture for an hour. Oxygenation parameters and mean airway pressures were noted at one hour, four hours, and five hours. Mortality, duration of ventilation, and the above parameters were compared in the two groups. Initial PRISM scores were similar in the two groups. Mortality in the prone group was less than in the supine group. The odds ratio of mortality was 0.20 (95% CI 0.05-0.75). Duration of ventilation was similar in the two groups. The oxygenation index was significantly lower in the prone group at one, four, and five hours after onset of ventilation. Prone position in the first few hours of ventilation significantly improves gas exchange and oxygenation, reduces the mean airway pressures required to ventilate children, and may cause significant improvement in survival. Our study protocol allowed ventilator settings to be changed as needed during ventilation.

Pretest Predictions for Phase II Ventilation Tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yiming Sun

The objective of this calculation is to predict the temperatures of the ventilating air, waste package surface, and concrete pipe walls that will be developed during the Phase II ventilation tests involving various test conditions. The results will be used as inputs to validating numerical approach for modeling continuous ventilation, and be used to support the repository subsurface design. The scope of the calculation is to identify the physical mechanisms and parameters related to thermal response in the Phase II ventilation tests, and describe numerical methods that are used to calculate the effects of continuous ventilation. The calculation is limitedmore » to thermal effect only. This engineering work activity is conducted in accordance with the ''Technical Work Plan for: Subsurface Performance Testing for License Application (LA) for Fiscal Year 2001'' (CRWMS M&O 2000d). This technical work plan (TWP) includes an AP-2.21Q, ''Quality Determinations and Planning for Scientific, Engineering, and Regulatory Compliance Activities'', activity evaluation (CRWMS M&O 2000d, Addendum A) that has determined this activity is subject to the YMP quality assurance (QA) program. The calculation is developed in accordance with the AP-3.12Q procedure, ''Calculations''. Additional background information regarding this activity is contained in the ''Development Plan for Ventilation Pretest Predictive Calculation'' (DP) (CRWMS M&O 2000a).« less

46 CFR 111.106-15 - Ventilation of hazardous locations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... its operational controls outside the ventilated space, if the system is mechanical; and (3) Have a... opening. (c) The mechanical ventilation of enclosed flammable or combustible liquid cargo handling or.... The power ventilation system must be designed to remove vapors from the bottom of the space at points...

Integrated Stress Response Mediates Epithelial Injury in Mechanical Ventilation.

PubMed

Dolinay, Tamas; Himes, Blanca E; Shumyatcher, Maya; Lawrence, Gladys Gray; Margulies, Susan S

2017-08-01

Ventilator-induced lung injury (VILI) is a severe complication of mechanical ventilation that can lead to acute respiratory distress syndrome. VILI is characterized by damage to the epithelial barrier with subsequent pulmonary edema and profound hypoxia. Available lung-protective ventilator strategies offer only a modest benefit in preventing VILI because they cannot impede alveolar overdistension and concomitant epithelial barrier dysfunction in the inflamed lung regions. There are currently no effective biochemical therapies to mitigate injury to the alveolar epithelium. We hypothesize that alveolar stretch activates the integrated stress response (ISR) pathway and that the chemical inhibition of this pathway mitigates alveolar barrier disruption during stretch and mechanical ventilation. Using our established rat primary type I-like alveolar epithelial cell monolayer stretch model and in vivo rat mechanical ventilation that mimics the alveolar overdistension seen in acute respiratory distress syndrome, we studied epithelial responses to mechanical stress. Our studies revealed that the ISR signaling pathway is a key modulator of epithelial permeability. We show that prolonged epithelial stretch and injurious mechanical ventilation activate the ISR, leading to increased alveolar permeability, cell death, and proinflammatory signaling. Chemical inhibition of protein kinase RNA-like endoplasmic reticulum kinase, an upstream regulator of the pathway, resulted in decreased injury signaling and improved barrier function after prolonged cyclic stretch and injurious mechanical ventilation. Our results provide new evidence that therapeutic targeting of the ISR can mitigate VILI.

Automated respiratory cycles selection is highly specific and improves respiratory mechanics analysis.

PubMed

Rigo, Vincent; Graas, Estelle; Rigo, Jacques

2012-07-01

Selected optimal respiratory cycles should allow calculation of respiratory mechanic parameters focusing on patient-ventilator interaction. New computer software automatically selecting optimal breaths and respiratory mechanics derived from those cycles are evaluated. Retrospective study. University level III neonatal intensive care unit. Ten mins synchronized intermittent mandatory ventilation and assist/control ventilation recordings from ten newborns. The ventilator provided respiratory mechanic data (ventilator respiratory cycles) every 10 secs. Pressure, flow, and volume waves and pressure-volume, pressure-flow, and volume-flow loops were reconstructed from continuous pressure-volume recordings. Visual assessment determined assisted leak-free optimal respiratory cycles (selected respiratory cycles). New software graded the quality of cycles (automated respiratory cycles). Respiratory mechanic values were derived from both sets of optimal cycles. We evaluated quality selection and compared mean values and their variability according to ventilatory mode and respiratory mechanic provenance. To assess discriminating power, all 45 "t" values obtained from interpatient comparisons were compared for each respiratory mechanic parameter. A total of 11,724 breaths are evaluated. Automated respiratory cycle/selected respiratory cycle selections agreement is high: 88% of maximal κ with linear weighting. Specificity and positive predictive values are 0.98 and 0.96, respectively. Averaged values are similar between automated respiratory cycle and ventilator respiratory cycle. C20/C alone is markedly decreased in automated respiratory cycle (1.27 ± 0.37 vs. 1.81 ± 0.67). Tidal volume apparent similarity disappears in assist/control: automated respiratory cycle tidal volume (4.8 ± 1.0 mL/kg) is significantly lower than for ventilator respiratory cycle (5.6 ± 1.8 mL/kg). Coefficients of variation decrease for all automated respiratory cycle parameters in all infants. "t" values from ventilator respiratory cycle data are two to three times higher than ventilator respiratory cycles. Automated selection is highly specific. Automated respiratory cycle reflects most the interaction of both ventilator and patient. Improving discriminating power of ventilator monitoring will likely help in assessing disease status and following trends. Averaged parameters derived from automated respiratory cycles are more precise and could be displayed by ventilators to improve real-time fine tuning of ventilator settings.

The Effect of Pressure-Controlled Ventilation and Volume-Controlled Ventilation in Prone Position on Pulmonary Mechanics and Inflammatory Markers.

PubMed

Şenay, Hasan; Sıvacı, Remziye; Kokulu, Serdar; Koca, Buğra; Bakı, Elif Doğan; Ela, Yüksel

2016-08-01

The aim of this present study is to compare the effect of pressure-controlled ventilation and volume-controlled ventilation on pulmonary mechanics and inflammatory markers in prone position. The study included 41 patients undergoing to vertebrae surgery. The patients were randomized into two groups: Group 1 received volume-controlled ventilation, while group 2 received pressure-controlled ventilation. The demographic data, pulmonary mechanics, the inflammatory marker levels just after the induction of anesthetics, at the 6th and 12th hours, and gas analysis from arterial blood samples taken at the beginning and the 30th minute were recorded. The inflammatory marker levels increased in both groups, without any significant difference among groups. Peak inspiratory pressure level was higher in the volume-controlled ventilation group. This study revealed that there is no difference regarding inflammatory marker levels between volume- and pressure-controlled ventilation.

Effect on lung function of mounthpiece ventilation in Steinert disease. A case report.

PubMed

Annunziata, Anna; Fiorentino, Giuseppe; Esquinas, Antonio

2017-03-01

In patients with muscular dystrophies both muscle length tension relationship changes and muscle elasticity and plasticity are decreased, resulting in impaired inspiratory muscle function and decreased vital capacity. Furthermore, the loss of deep breathing further increases the risk of alveolar collapse, hypoventilation and atelectasias. In this case report, a stable improvement of vital capacity after treatment with mounthpiece ventilation (MPV), was observed, suggesting that not invasive ventilation (NIV) might help to maintai lung and chest wall compliance, prevent hypoventilation and atelectasias which in turn may slow down the development of the restrictive respiratory pattern. The improvement of vital capacity may have a positive impact on alveolar ventilation by reducing the time with SaO2 values below 90%. This case illustrates that MPV is an effective method to improve respiratory function in patients non-tolerant of nasal mask and a valid alternative option for those who need NIV support for the most part of the day. Furthermore, the use of MPV, alone or combined with other interfaces, improves the quality of life of the neuromuscular patients and promotes a greater adherence to mechanical ventilation.

A taxonomy for mechanical ventilation: 10 fundamental maxims.

PubMed

Chatburn, Robert L; El-Khatib, Mohamad; Mireles-Cabodevila, Eduardo

2014-11-01

The American Association for Respiratory Care has declared a benchmark for competency in mechanical ventilation that includes the ability to "apply to practice all ventilation modes currently available on all invasive and noninvasive mechanical ventilators." This level of competency presupposes the ability to identify, classify, compare, and contrast all modes of ventilation. Unfortunately, current educational paradigms do not supply the tools to achieve such goals. To fill this gap, we expand and refine a previously described taxonomy for classifying modes of ventilation and explain how it can be understood in terms of 10 fundamental constructs of ventilator technology: (1) defining a breath, (2) defining an assisted breath, (3) specifying the means of assisting breaths based on control variables specified by the equation of motion, (4) classifying breaths in terms of how inspiration is started and stopped, (5) identifying ventilator-initiated versus patient-initiated start and stop events, (6) defining spontaneous and mandatory breaths, (7) defining breath sequences (8), combining control variables and breath sequences into ventilatory patterns, (9) describing targeting schemes, and (10) constructing a formal taxonomy for modes of ventilation composed of control variable, breath sequence, and targeting schemes. Having established the theoretical basis of the taxonomy, we demonstrate a step-by-step procedure to classify any mode on any mechanical ventilator. Copyright © 2014 by Daedalus Enterprises.

Lung-protective ventilation in abdominal surgery.

PubMed

Futier, Emmanuel; Jaber, Samir

2014-08-01

To provide the most recent and relevant clinical evidence regarding the use of prophylactic lung-protective mechanical ventilation in abdominal surgery. Evidence is accumulating, suggesting an association between intraoperative mechanical ventilation strategy and postoperative pulmonary complications in patients undergoing abdominal surgery. Nonprotective ventilator settings, especially high tidal volume (>10-12 ml/kg), very low level of positive end-expiratory pressure (PEEP, <5 cm H2O), or no PEEP, may cause alveolar overdistension and repetitive tidal recruitment leading to ventilator-associated lung injury in patients with healthy lungs. Stimulated by the previous findings in patients with acute respiratory distress syndrome, the use of lower tidal volume ventilation is becoming increasingly more common in the operating room. However, lowering tidal volume, though important, is only part of the overall multifaceted approach of lung-protective mechanical ventilation. Recent data provide compelling evidence that prophylactic lung-protective mechanical ventilation using lower tidal volume (6-8 ml/kg of predicted body weight), moderate PEEP (6-8 cm H2O), and recruitment maneuvers is associated with improved functional or physiological and clinical postoperative outcome in patients undergoing abdominal surgery. The use of prophylactic lung-protective ventilation can help in improving the postoperative outcome.

Evidence to Support Tooth Brushing in Critically Ill Patients

PubMed Central

Ames, Nancy J.

2012-01-01

Tooth brushing in critically ill patients has been advocated by many as a standard of care despite the limited evidence to support this practice. Attention has been focused on oral care as the evidence accumulates to support an association between the bacteria in the oral microbiome and those respiratory pathogens that cause pneumonia. It is plausible to assume that respiratory pathogens originating in the oral cavity are aspirated into the lungs, causing infection. A recent study of the effects of a powered toothbrush on the incidence of ventilator-associated pneumonia was stopped early because of a lack of effect in the treatment group. This review summarizes the evidence that supports the effectiveness of tooth brushing in critically ill adults and children receiving mechanical ventilation. Possible reasons for the lack of benefit of tooth brushing demonstrated in clinical trials are discussed. Recommendations for future trials in critically ill patients are suggested. With increased emphasis being placed on oral care, the evidence that supports this intervention must be evaluated carefully. PMID:21532045

Evidence to support tooth brushing in critically ill patients.

PubMed

Ames, Nancy J

2011-05-01

Tooth brushing in critically ill patients has been advocated by many as a standard of care despite the limited evidence to support this practice. Attention has been focused on oral care as the evidence accumulates to support an association between the bacteria in the oral microbiome and those respiratory pathogens that cause pneumonia. It is plausible to assume that respiratory pathogens originating in the oral cavity are aspirated into the lungs, causing infection. A recent study of the effects of a powered toothbrush on the incidence of ventilator-associated pneumonia was stopped early because of a lack of effect in the treatment group. This review summarizes the evidence that supports the effectiveness of tooth brushing in critically ill adults and children receiving mechanical ventilation. Possible reasons for the lack of benefit of tooth brushing demonstrated in clinical trials are discussed. Recommendations for future trials in critically ill patients are suggested. With increased emphasis being placed on oral care, the evidence that supports this intervention must be evaluated carefully.

Analysis of Complaints from Patients During Mechanical Ventilation After Cardiac Surgery: A Retrospective Study.

PubMed

Wang, Yi; Li, Hua; Zou, Honglin; Li, Yaxiong

2015-08-01

This study analyzed major complaints from patients during mechanical ventilation after cardiac surgery and identified the most common complaints to reduce adverse psychologic responses. Retrospective. A single tertiary university hospital. Patients with heart disease who were on mechanical ventilation after cardiac surgery (N = 800). The major complaints of the patients during mechanical ventilation after cardiac surgery were analyzed. Patients' comfort was evaluated using a visual analog scale, and the factors affecting comfort were analyzed. The average visual analog scale score in all patients was 5.8±2.0, and most patients presented moderate discomfort. The factors affecting comfort included dry mouth, thirst, tracheal intubation, aspiration of sputum, communication barriers, limited mobility, fear/anxiety, patient-ventilator dyssynchrony, and poor environmental conditions. Of these factors, 8 were independent predictors of the visual analog scale score. Patients considered mechanical ventilation to be the worst part of their hospitalization. The study identified 8 independent factors causing discomfort in patients during mechanical ventilation after cardiac surgery. Clinicians should take appropriate measures and implement nursing interventions to reduce suffering, physical and psychologic trauma, and adverse psychologic responses and to promote recovery. Copyright © 2015 Elsevier Inc. All rights reserved.

Contributing Factors for Morbidity and Mortality in Patients with Organophosphate Poisoning on Mechanical Ventilation: A Retrospective Study in a Teaching Hospital

PubMed Central

Patil, Gurulingappa; Nikhil, M.

2016-01-01

Introduction One of the most common causes of poisoning in agricultural based developing countries like India is due to Organophosphorus (OP) compound. Its widespread use and easy availability has increased the likelihood of poisoning with these compounds. Aim To study the morbidity and mortality in patients with acute OP poisoning requiring mechanical ventilation. Materials and Methods This was a retrospective study constituting patients of all age groups admitted to the Intensive Care Unit (ICU) with diagnosis of OP poisoning between January 2015 to December 2015. Of 66 OP poisoning cases those patients who went against medical advice, 20 were excluded from the study and thus 46 patients were included. Diagnosis was performed from the history taken either from the patient or from the patient’s relatives and presenting symptoms. Demographic data, month of the year, age of patient, mode of poisoning, cholinesterase levels, duration of mechanical ventilation and mortality were recorded. Data are presented as mean±SD. Results A 97.83% (45/46) of cases were suicidal. Out of 46, 9 were intubated and mechanically ventilated. Duration of mechanical ventilation varied from less than 48 hours to more than 7 days. Mortality rate was 50%, 0% and 100% in those who required mechanical ventilation for more than 7 days, 2 to 7 days and <2days respectively. None of the predictors like age, severity of poisoning, cholinesterase levels and duration of ventilation were independent predictors of death and all of them contributed to the mortality. Overall mortality rate in those who required mechanical ventilation was 22.22%. Conclusion Morbidity and mortality due to OP poisoning is directly proportional to the age, severity of poisoning and duration of mechanical ventilation and inversely proportional to serum cholinesterase level. PMID:28208980

Lung protective mechanical ventilation and two year survival in patients with acute lung injury: prospective cohort study.

PubMed

Needham, Dale M; Colantuoni, Elizabeth; Mendez-Tellez, Pedro A; Dinglas, Victor D; Sevransky, Jonathan E; Dennison Himmelfarb, Cheryl R; Desai, Sanjay V; Shanholtz, Carl; Brower, Roy G; Pronovost, Peter J

2012-04-05

To evaluate the association of volume limited and pressure limited (lung protective) mechanical ventilation with two year survival in patients with acute lung injury. Prospective cohort study. 13 intensive care units at four hospitals in Baltimore, Maryland, USA. 485 consecutive mechanically ventilated patients with acute lung injury. Two year survival after onset of acute lung injury. 485 patients contributed data for 6240 eligible ventilator settings, as measured twice daily (median of eight eligible ventilator settings per patient; 41% of which adhered to lung protective ventilation). Of these patients, 311 (64%) died within two years. After adjusting for the total duration of ventilation and other relevant covariates, each additional ventilator setting adherent to lung protective ventilation was associated with a 3% decrease in the risk of mortality over two years (hazard ratio 0.97, 95% confidence interval 0.95 to 0.99, P=0.002). Compared with no adherence, the estimated absolute risk reduction in two year mortality for a prototypical patient with 50% adherence to lung protective ventilation was 4.0% (0.8% to 7.2%, P=0.012) and with 100% adherence was 7.8% (1.6% to 14.0%, P=0.011). Lung protective mechanical ventilation was associated with a substantial long term survival benefit for patients with acute lung injury. Greater use of lung protective ventilation in routine clinical practice could reduce long term mortality in patients with acute lung injury. Clinicaltrials.gov NCT00300248.

Impact of Individualized Diet Intervention on Body Composition and Respiratory Variables in Children With Respiratory Insufficiency: A Pilot Intervention Study.

PubMed

Martinez, Enid E; Bechard, Lori J; Smallwood, Craig D; Duggan, Christopher P; Graham, Robert J; Mehta, Nilesh M

2015-07-01

Diet modification may improve body composition and respiratory variables in children with respiratory insufficiency. Our objective was to examine the effect of an individualized diet intervention on changes in weight, lean body mass, minute ventilation, and volumetric CO2 production in children dependent on long-term mechanical ventilatory support. Prospective, open-labeled interventional study. Study subjects' homes. Children, 1 month to 17 years old, dependent on at least 12 hr/d of transtracheal mechanical ventilatory support. Twelve weeks of an individualized diet modified to deliver energy at 90-110% of measured energy expenditure and protein intake per age-based guidelines. During a multidisciplinary home visit, we obtained baseline values of height and weight, lean body mass percent by bioelectrical impedance analysis, actual energy and protein intake by food record, and measured energy expenditure by indirect calorimetry. An individualized diet was then prescribed to optimize energy and protein intake. After 12 weeks on this interventional diet, we evaluated changes in weight, height, lean body mass percent, minute ventilation, and volumetric CO2 production. Sixteen subjects, mean age 9.3 years (SD, 4.9), eight male, completed the study. For the diet intervention, a majority of subjects required a change in energy and protein prescription. The mean percentage of energy delivered as carbohydrate was significantly decreased, 51.7% at baseline versus 48.2% at follow-up, p = 0.009. Mean height and weight increased on the modified diet. Mean lean body mass percent increased from 58.3% to 61.8%. Minute ventilation was significantly lower (0.18 L/min/kg vs 0.15 L/min/kg; p = 0.04), and we observed a trend toward lower volumetric CO2 production (5.4 mL/min/kg vs 5.3 mL/min/kg; p = 0.06) after 12 weeks on the interventional diet. Individualized diet modification is feasible and associated with a significant decrease in minute ventilation, a trend toward significant reduction in CO2 production, and improved body composition in children on long-term mechanical ventilation. Optimization of respiratory variables and lean body mass by diet modification may benefit children with respiratory insufficiency in the ICU.

Being the lifeline: the parent experience of caring for a child with neuromuscular disease on home mechanical ventilation.

PubMed

Mah, Jean K; Thannhauser, Jennifer E; McNeil, Deborah A; Dewey, Deborah

2008-12-01

We describe the experience of parents caring for children with neuromuscular disease (NMD) on home mechanical ventilation (HMV). Data was obtained from semi-structured interviews and analyzed using a phenomenological framework. Fifteen families including 19 parents of children with DMD (n=3), SMA (n=5), and other NMD (n=7) participated. The central theme of these parents' experience was being the "lifeline" for their child's life and quality of life. The families' lives changed significantly with the decision to place their child on HMV; over time, these changes became part of their new "normal". Despite becoming expert caregivers, the parents experienced a recurrent sense of loss and uncertainty. Those who perceived insufficient support felt the weight of responsibility as sole care providers for their child with NMD. Beyond recognizing the parents as experts, more support by health care professionals, their extended family, and their community are needed to enable parents to fulfill their vital role.

Mechanical stress induces lung fibrosis by epithelial-mesenchymal transition.

PubMed

Cabrera-Benítez, Nuria E; Parotto, Matteo; Post, Martin; Han, Bing; Spieth, Peter M; Cheng, Wei-Erh; Valladares, Francisco; Villar, Jesús; Liu, Mingayo; Sato, Masaaki; Zhang, Haibo; Slutsky, Arthur S

2012-02-01

Many mechanically ventilated patients with acute respiratory distress syndrome develop pulmonary fibrosis. Stresses induced by mechanical ventilation may explain the development of fibrosis by a number of mechanisms (e.g., damage the alveolar epithelium, biotrauma). The objective of this study was t test the hypothesis that mechanical ventilation plays an important role in the pathogenesis of lung fibrosis. C57BL/6 mice were randomized into four groups: healthy controls; hydrochloric acid aspiration alone; vehicle control solution followed 24 hrs later by mechanical ventilation (peak inspiratory pressure 22 cm H(2)O and positive end-expiratory pressure 2 cm H(2)O for 2 hrs); and acid aspiration followed 24 hrs later by mechanical ventilation. The animals were monitored for up to 15 days after acid aspiration. To explore the direct effects of mechanical stress on lung fibrotic formation, human lung epithelial cells (BEAS-2B) were exposed to mechanical stretch for up to 48 hrs. Impaired lung mechanics after mechanical ventilation was associated with increased lung hydroxyproline content, and increased expression of transforming growth factor-β, β-catenin, and mesenchymal markers (α-smooth muscle actin and vimentin) at both the gene and protein levels. Expression of epithelial markers including cytokeratin-8, E-cadherin, and prosurfactant protein B decreased. Lung histology demonstrated fibrosis formation and potential epithelia-mesenchymal transition. In vitro direct mechanical stretch of BEAS-2B cells resulted in similar fibrotic and epithelia-mesenchymal transition formation. Mechanical stress induces lung fibrosis, and epithelia-mesenchymal transition may play an important role in mediating the ventilator-induced lung fibrosis.

Evaluation of delivery of enteral nutrition in mechanically ventilated Malaysian ICU patients.

PubMed

Yip, Keng F; Rai, Vineya; Wong, Kang K

2014-01-01

There are numerous challenges in providing nutrition to the mechanically ventilated critically ill ICU patient. Understanding the level of nutritional support and the barriers to enteral feeding interruption in mechanically ventilated patients are important to maximise the nutritional benefits to the critically ill patients. Thus, this study aims to evaluate enteral nutrition delivery and identify the reasons for interruptions in mechanically ventilated Malaysian patients receiving enteral feeding. A cross sectional prospective study of 77 consecutive patients who required mechanical ventilation and were receiving enteral nutrition was done in an open 14-bed intensive care unit of a tertiary hospital. Data were collected prospectively over a 3 month period. Descriptive statistical analysis were made with respect to demographical data, time taken to initiate feeds, type of feeds, quantification of feeds attainment, and reasons for feed interruptions. There are no set feeding protocols in the ICU. The usual initial rate of enteral nutrition observed in ICU was 20 ml/hour, assessed every 6 hours and the decision was made thereafter to increase feeds. The target calorie for each patient was determined by the clinician alongside the dietitian. The use of prokinetic agents was also prescribed at the discretion of the attending clinician and is commonly IV metoclopramide 10 mg three times a day. About 66% of patients achieved 80% of caloric requirements within 3 days of which 46.8% achieved full feeds in less than 12 hours. The time to initiate feeds for patients admitted into the ICU ranged from 0 - 110 hours with a median time to start feeds of 15 hours and the interquartile range (IQR) of 6-59 hours. The mean time to achieve at least 80% of nutritional target was 1.8 days ± 1.5 days. About 79% of patients experienced multiple feeding interruptions. The most prevalent reason for interruption was for procedures (45.1%) followed by high gastric residual volume (38.0%), diarrhoea (8.4%), difficulty in nasogastric tube placement (5.6%) and vomiting (2.9%). Nutritional inadequacy in mechanically ventilated Malaysian patients receiving enteral nutrition was not as common as expected. However, there is still room for improvement with regards to decreasing the number of patients who did not achieve their caloric requirement throughout their stay in the ICU.

[Analgesia, sedation and relaxation in the child with mechanical ventilation].

PubMed

Valdivielso-Serna, A

2008-02-01

The basic concepts of sedation and analgesia and the tools to asses the level of sedation and analgesia are review. The different methods of sedation and the non pharmacological interventions are described. Sedatives, analgesics and muscle relaxants, their pharmacodynamics and pharmacokinetics in children, their indications in specific situations (intubation, pain control, sedation and neuromuscular blocking) are reviewed. The etiology of patient-ventilator asynchrony in ventilated children and how to treat it are analyzed, giving guides of how to adapt sedation to the level of mechanical ventilation therapy. Finally, general recommendations are given for the analgesia and sedation in mechanically ventilated children.

Coexistence of Ureaplasma and chorioamnionitis is associated with prolonged mechanical ventilation.

PubMed

Jung, Euiseok; Choi, Chang Won; Kim, Su Yeong; Sung, Tae-Jung; Kim, Haeryoung; Park, Kyoung Un; Kim, Han-Suk; Kim, Beyong Il; Choi, Jung-Hwan

2017-01-01

Both histologic chorioamnionitis (HCAM) and Ureaplasma infection are considered important contributors to perinatal lung injury. We tested the hypothesis that coexistence of maternal HCAM and perinatal Ureaplasma exposure increases the risk of prolonged mechanical ventilation in extremely low-birthweight (ELBW) infants. A retrospective cohort study was carried out of all ELBW infants born between January 2008 and December 2013 at a single academic center. Placental pathology and gastric fluid Ureaplasma data were available for all infants. Culture and polymerase chain reaction were used to detect Ureaplasma in gastric fluid. Prolonged mechanical ventilation was defined as mechanical ventilation that began within 28 days after birth and continued. Of 111 ELBW infants enrolled, 84 survived beyond 36 weeks of postmenstrual age (PMA) and were included in the analysis. Eighteen infants (21.4%) had both HCAM and Ureaplasma exposure. Seven infants (8.3%) required mechanical ventilation beyond 36 weeks of PMA. Coexistence of HCAM and Ureaplasma in gastric fluid was significantly associated with prolonged mechanical ventilation after adjustment for gestational age, sex, mode of delivery, and use of macrolide antibiotics (OR, 8.7; 95%CI: 1.1-67.2). Coexistence of maternal HCAM and perinatal Ureaplasma exposure significantly increases the risk of prolonged mechanical ventilation in ELBW infants. © 2016 Japan Pediatric Society.

Pressure-limited sustained inflation vs. gradual tidal inflations for resuscitation in preterm lambs.

PubMed

Tingay, David G; Polglase, Graeme R; Bhatia, Risha; Berry, Clare A; Kopotic, Robert J; Kopotic, Clinton P; Song, Yong; Szyld, Edgardo; Jobe, Alan H; Pillow, J Jane

2015-04-01

Support of the mechanically complex preterm lung needs to facilitate aeration while avoiding ventilation heterogeneities: whether to achieve this gradually or quickly remains unclear. We compared the effect of gradual vs. constant tidal inflations and a pressure-limited sustained inflation (SI) at birth on gas exchange, lung mechanics, gravity-dependent lung volume distribution, and lung injury in 131-day gestation preterm lambs. Lambs were resuscitated with either 1) a 20-s, 40-cmH2O pressure-limited SI (PressSI), 2) a gradual increase in tidal volume (Vt) over 5-min from 3 ml/kg to 7 ml/kg (IncrVt), or 3) 7 ml/kg Vt from birth. All lambs were subsequently ventilated for 15 min with 7 ml/kg Vt with the same end-expiratory pressure. Lung mechanics, gas exchange and spatial distribution of end-expiratory volume (EEV), and tidal ventilation (electrical impedance tomography) were recorded regularly. At 15 min, early mRNA tissue markers of lung injury were assessed. The IncrVt group resulted in greater tissue hysteresivity at 5 min (P = 0.017; two-way ANOVA), higher alveolar-arterial oxygen difference from 10 min (P < 0.01), and least uniform gravity-dependent distribution of EEV. There were no other differences in lung mechanics between groups, and the PressSI and 7 ml/kg Vt groups behaved similarly throughout. EEV was more uniformly distributed, but Vt least so, in the PressSI group. There were no differences in mRNA markers of lung injury. A gradual increase in Vt from birth resulted in less recruitment of the gravity-dependent lung with worse oxygenation. There was no benefit of a SI at birth over mechanical ventilation with 7 ml/kg Vt. Copyright © 2015 the American Physiological Society.

Does an oral care protocol reduce VAP in patients with a tracheostomy?

PubMed

Conley, Patricia; McKinsey, David; Graff, Jason; Ramsey, Anthony R

2013-07-01

Several studies have demonstrated that oral care with chlorhexidine gluconate (CHG) 0.12% solution reduces the incidence of ventilator-associated pneumonia (VAP) in mechanically ventilated patients with endotracheal tubes in the ICU. Minimal evidence shows the effectiveness of any oral care protocols in preventing VAP in mechanically ventilated patients with tracheostomies in a step-down or progressive care unit (PCU). To determine the effectiveness of an oral care protocol in reducing the VAP rate in mechanically ventilated patients with tracheostomies in the PCU. A 12-month prospective study was conducted on 75 mechanically ventilated patients who had tracheostomies. The oral care protocol consisted of tooth brushing with toothpaste and applying CHG 0.12% solution every 12 hours. At the conclusion of the study, the VAP rate in the study population was compared with the National Health and Safety Network (NHSN) report for 2009 benchmark of 1.5 per 1,000 ventilator days. After the oral care protocol was implemented in the PCU, the VAP rate was 1.1 per 1,000 ventilator days over 12 months, compared with the NHSN report for 2009 of 1.5 per 1,000 ventilator days. Tooth brushing with toothpaste and applying CHG 0.12% solution may be an effective oral care protocol to reduce the VAP rate in patients in PCUs with tracheostomies who are being mechanically ventilated.

Association Between Enteral Feeding, Weight Status, and Mortality in a Medical Intensive Care Unit.

PubMed

Vest, Michael T; Kolm, Paul; Bowen, James; Trabulsi, Jillian; Lennon, Shannon L; Shapero, Mary; McGraw, Patty; Halbert, James; Jurkovitz, Claudine

2018-03-01

Clinical practice guidelines recommend enteral nutrition for most patients receiving mechanical ventilation. However, recently published evidence on the effect of enteral nutrition on mortality, particularly for patients who are well nourished, is conflicting. To examine the association between enteral feeding and hospital mortality in critically ill patients receiving mechanical ventilation and to determine if body mass index mediates this relationship. A retrospective cohort study of patients receiving mechanical ventilation admitted to a medical intensive care unit in 2013. Demographic and clinical variables were collected. Cox proportional hazards regression was used to examine the relationship between an enteral feeding order and hospital mortality and to determine if the relationship was mediated by body mass index. Of 777 patients who had 811 hospitalizations requiring mechanical ventilation, 182 (23.4%) died in the hospital. A total of 478 patients (61.5%) received an order for enteral tube feeding, which was associated with a lower risk of death (hazard ratio, 0.41; 95% CI, 0.29-0.59). Body mass index did not mediate the relationship between mortality and receipt of an order for enteral feeding. Median stay in the unit was 3.6 days. Most deaths (72.0%) occurred more than 48 hours after admission. The finding of a positive association between an order for enteral feeding and survival supports enteral feeding of patients in medical intensive care units. Furthermore, the beneficial effect of enteral feeding appears to apply to patients regardless of body mass index. ©2018 American Association of Critical-Care Nurses.

Comparison of lung protective ventilation strategies in a rabbit model of acute lung injury.

PubMed

Rotta, A T; Gunnarsson, B; Fuhrman, B P; Hernan, L J; Steinhorn, D M

2001-11-01

To determine the impact of different protective and nonprotective mechanical ventilation strategies on the degree of pulmonary inflammation, oxidative damage, and hemodynamic stability in a saline lavage model of acute lung injury. A prospective, randomized, controlled, in vivo animal laboratory study. Animal research facility of a health sciences university. Forty-six New Zealand White rabbits. Mature rabbits were instrumented with a tracheostomy and vascular catheters. Lavage-injured rabbits were randomized to receive conventional ventilation with either a) low peak end-expiratory pressure (PEEP; tidal volume of 10 mL/kg, PEEP of 2 cm H2O); b) high PEEP (tidal volume of 10 mL/kg, PEEP of 10 cm H2O); c) low tidal volume with PEEP above Pflex (open lung strategy, tidal volume of 6 mL/kg, PEEP set 2 cm H2O > Pflex); or d) high-frequency oscillatory ventilation. Animals were ventilated for 4 hrs. Lung lavage fluid and tissue samples were obtained immediately after animals were killed. Lung lavage fluid was assayed for measurements of total protein, elastase activity, tumor necrosis factor-alpha, and malondialdehyde. Lung tissue homogenates were assayed for measurements of myeloperoxidase activity and malondialdehyde. The need for inotropic support was recorded. Animals that received a lung protective strategy (open lung or high-frequency oscillatory ventilation) exhibited more favorable oxygenation and lung mechanics compared with the low PEEP and high PEEP groups. Animals ventilated by a lung protective strategy also showed attenuation of inflammation (reduced tracheal fluid protein, tracheal fluid elastase, tracheal fluid tumor necrosis factor-alpha, and pulmonary leukostasis). Animals treated with high-frequency oscillatory ventilation had attenuated oxidative injury to the lung and greater hemodynamic stability compared with the other experimental groups. Both lung protective strategies were associated with improved oxygenation, attenuated inflammation, and decreased lung damage. However, in this small-animal model of acute lung injury, an open lung strategy with deliberate hypercapnia was associated with significant hemodynamic instability.

[The incidence and risk factors of ventilator-associated pneumonia in patients with severe traumatic brain injury].

PubMed

Marjanović, Vesna; Novak, Vesna; Velicković, Ljubinka; Marjanović, Goran

2011-01-01

Patients with severe traumatic brain injury are at a risk of developing ventilator-associated pneumonia. The aim of this study was to describe the incidence, etiology, risk factors for development of ventilator-associated pneumonia and outcome in patients with severe traumatic brain injury. A retrospective study was done in 72 patients with severe traumatic brain injury, who required mechanical ventilation for more than 48 hours. Ventilator-associated pneumonia was found in 31 of 72 (43.06%) patients with severe traumatic brain injury. The risk factors for ventilator-associated pneumonia were: prolonged mechanical ventilation (12.42 vs 4.34 days, p < 0.001), longer stay at intensive care unit (17 vs 5 days, p < 0.001) and chest injury (51.61 vs 19.51%, p < 0.009) compared to patients without ventilator-associated pneumonia. The mortality rate in the patients with ventilator-associated pneumonia was higher (38.71 vs 21.95%, p = 0.12). The development of ventilator-associated pneumonia in patients with severe traumatic brain injury led to the increased morbidity due to the prolonged mechanical ventilation, longer stay at intensive care unit and chest injury, but had no effect on mortality.

Variation in Definition of Prolonged Mechanical Ventilation.

PubMed

Rose, Louise; McGinlay, Michael; Amin, Reshma; Burns, Karen Ea; Connolly, Bronwen; Hart, Nicholas; Jouvet, Philippe; Katz, Sherri; Leasa, David; Mawdsley, Cathy; McAuley, Danny F; Schultz, Marcus J; Blackwood, Bronagh

2017-10-01

Consistency of definitional criteria for terminology applied to describe subject cohorts receiving mechanical ventilation within ICU and post-acute care settings is important for understanding prevalence, risk stratification, effectiveness of interventions, and projections for resource allocation. Our objective was to quantify the application and definition of terms for prolonged mechanical ventilation. We conducted a scoping review of studies (all designs except single-case study) reporting a study population (adult and pediatric) using the term prolonged mechanical ventilation or a synonym. We screened 5,331 references, reviewed 539 full-text references, and excluded 120. Of the 419 studies (representing 38 countries) meeting inclusion criteria, 297 (71%) reported data on a heterogeneous subject cohort, and 66 (16%) included surgical subjects only (46 of those 66, 70% cardiac surgery). Other studies described COPD (16, 4%), trauma (22, 5%), neuromuscular (17, 4%), and sepsis (1, 0.2%) cohorts. A total of 741 terms were used to refer to the 419 study cohorts. The most common terms were: prolonged mechanical ventilation (253, 60%), admission to specialized unit (107, 26%), and long-term mechanical ventilation (79, 19%). Some authors (282, 67%) defined their cohorts based on duration of mechanical ventilation, with 154 studies (55%) using this as the sole criterion. We identified 37 different durations of ventilation ranging from 5 h to 1 y, with > 21 d being the most common (28 of 282, 7%). For studies describing a surgical cohort, minimum ventilation duration required for inclusion was ≥ 24 h for 20 of 66 studies (30%). More than half of all studies (237, 57%) did not provide a reason/rationale for definitional criteria used, with only 28 studies (7%) referring to a consensus definition. We conclude that substantial variation exists in the terminology and definitional criteria for cohorts of subjects receiving prolonged mechanical ventilation. Standardization of terminology and definitional criteria is required for study data to be maximally informative. Copyright © 2017 by Daedalus Enterprises.

Extracorporeal Life Support for Severe Acute Respiratory Distress Syndrome in Adults

PubMed Central

Hemmila, Mark R.; Rowe, Stephen A.; Boules, Tamer N.; Miskulin, Judiann; McGillicuddy, John W.; Schuerer, Douglas J.; Haft, Jonathan W.; Swaniker, Fresca; Arbabi, Saman; Hirschl, Ronald B.; Bartlett, Robert H.

2004-01-01

Objective: Severe acute respiratory distress syndrome (ARDS) is associated with a high level of mortality. Extracorporeal life support (ECLS) during severe ARDS maintains oxygen and carbon dioxide gas exchange while providing an optimal environment for recovery of pulmonary function. Since 1989, we have used a protocol-driven algorithm for treatment of severe ARDS, which includes the use of ECLS when standard therapy fails. The objective of this study was to evaluate our experience with ECLS in adult patients with severe ARDS with respect to mortality and morbidity. Methods: We reviewed our complete experience with ELCS in adults from January 1, 1989, through December 31, 2003. Severe ARDS was defined as acute onset pulmonary failure, with bilateral infiltrates on chest x-ray, and PaO2/fraction of inspired oxygen (FiO2) ratio ≤100 or A-aDO2 >600 mm Hg despite maximal ventilator settings. The indication for ECLS was acute severe ARDS unresponsive to optimal conventional treatment. The technique of ECLS included veno-venous or veno-arterial vascular access, lung “rest” at low FiO2 and inspiratory pressure, minimal anticoagulation, and optimization of systemic oxygen delivery. Results: During the study period, ECLS was used for 405 adult patients age 17 or older. Of these 405 patients, 255 were placed on ECLS for severe ARDS refractory to all other treatment. Sixty-seven percent were weaned off ECLS, and 52% survived to hospital discharge. Multivariate logistic regression analysis identified the following pre-ELCS variables as significant independent predictors of survival: (1) age (P = 0.01); (2) gender (P = 0.048); (3) pH ≤7.10 (P = 0.01); (4) PaO2/FiO2 ratio (P = 0.03); and (5) days of mechanical ventilation (P < 0.001). None of the patients who survived required permanent mechanical ventilation or supplemental oxygen therapy. Conclusion: Extracorporeal life support for severe ARDS in adults is a successful therapeutic option in those patients who do not respond to conventional mechanical ventilator strategies. PMID:15383787

A comprehensive evaluation of the toxicology resulting from laser-generated ventilation holes in cigarette filters.

PubMed

Coggins, Christopher R E; Merski, Jerome A; Oldham, Michael J

2013-01-01

Recent technological advances allow ventilation holes in (or adjacent to) cigarette filters to be produced using lasers instead of using the mechanical procedures of earlier techniques. Analytical chemistry can be used to compare the composition of mainstream smoke from experimental cigarettes having filters with mechanically produced ventilation holes to that of cigarettes with ventilation holes that were produced using laser technology. Established procedures were used to analyze the smoke composition of 38 constituents of mainstream smoke generated using standard conditions. There were no differences between the smoke composition of cigarettes with filter ventilation holes that were produced mechanically or through use of laser technology. The two methods for producing ventilation holes in cigarette filters are equivalent in terms of resulting mainstream smoke chemistry, at two quite different filter ventilation percentages.

Respiratory pathogen colonization of dental plaque, the lower airways, and endotracheal tube biofilms during mechanical ventilation.

PubMed

Sands, Kirsty M; Wilson, Melanie J; Lewis, Michael A O; Wise, Matt P; Palmer, Nicki; Hayes, Anthony J; Barnes, Rosemary A; Williams, David W

2017-02-01

In mechanically ventilated patients, the endotracheal tube is an essential interface between the patient and ventilator, but inadvertently, it also facilitates the development of ventilator-associated pneumonia (VAP) by subverting pulmonary host defenses. A number of investigations suggest that bacteria colonizing the oral cavity may be important in the etiology of VAP. The present study evaluated microbial changes that occurred in dental plaque and lower airways of 107 critically ill mechanically ventilated patients. Dental plaque and lower airways fluid was collected during the course of mechanical ventilation, with additional samples of dental plaque obtained during the entirety of patients' hospital stay. A "microbial shift" occurred in dental plaque, with colonization by potential VAP pathogens, namely, Staphylococcus aureus and Pseudomonas aeruginosa in 35 patients. Post-extubation analyses revealed that 70% and 55% of patients whose dental plaque included S aureus and P aeruginosa, respectively, reverted back to having a predominantly normal oral microbiota. Respiratory pathogens were also isolated from the lower airways and within the endotracheal tube biofilms. To the best of our knowledge, this is the largest study to date exploring oral microbial changes during both mechanical ventilation and after recovery from critical illness. Based on these findings, it was apparent that during mechanical ventilation, dental plaque represents a source of potential VAP pathogens. Copyright © 2016 Elsevier Inc. All rights reserved.

The effect of music therapy on physiological signs of anxiety in patients receiving mechanical ventilatory support.

PubMed

Korhan, Esra Akin; Khorshid, Leyla; Uyar, Mehmet

2011-04-01

The aim of this study was to investigate if relaxing music is an effective method of reducing the physiological signs of anxiety in patients receiving mechanical ventilatory support. Few studies have focused on the effect of music on physiological signs of anxiety in patients receiving mechanical ventilatory support. A study-case-control, experimental repeated measures design was used. Sixty patients aged 18-70 years, receiving mechanical ventilatory support and hospitalised in the intensive care unit, were taken as a convenience sample. Participants were randomised to a control group or intervention group, who received 60 minutes of music therapy. Classical music was played to patients using media player (MP3) and headphones. Subjects had physiological signs taken immediately before the intervention and at the 30th, 60th and 90th minutes of the intervention. Physiological signs of anxiety assessed in this study were mean systolic and diastolic blood pressure, pulse rate, respiratory rate and oxygen saturation in blood measured by pulse oxymetry. Data were collected over eight months in 2006-2007. The music group had significantly lower respiratory rates, and systolic and diastolic blood pressure, than the control group. This decrease improved progressively in the 30th, 60th and 90th minutes of the intervention, indicating a cumulative dose effect. Music can provide an effective method of reducing potentially harmful physiological responses arising from anxiety. As indicated by the results of this study, music therapy can be supplied to allay anxiety in patients receiving mechanical ventilation. Nurses may include music therapy in the routine care of patients receiving mechanical ventilation. © 2011 Blackwell Publishing Ltd.

Nebulization of antimicrobial agents in mechanically ventilated adults in 2017: an international cross-sectional survey.

PubMed

Alves, Joana; Alp, Emine; Koulenti, Despoina; Zhang, Zhongheng; Ehrmann, Stephan; Blot, Stijn; Bassetti, Matteo; Conway-Morris, Andrew; Reina, Rosa; Teran, Enrique; Sole-Lleonart, Candela; Ruiz-Rodríguez, Maria; Rello, Jordi

2018-04-01

2017 ESCMID practice guidelines reported safety concerns and weak evidence of benefit supporting use of aerosolized antibiotics in mechanically ventilated patients. Our primary goal was to assess current patterns of aerosolized antibiotic prescription in mechanically ventilated patients. A sequential global survey was performed prior to the release of the ESCMID guidelines, from the 1st of February to the 30th of April 2017, using an electronic platform. Responses were analyzed comparing geographical regions. A total of 410 units responded, with 261 (177 from Europe) being eligible for the full survey. 26.8% of units reported not using aerosolized antibiotics. The two major indications amongst prescribing units were ventilator-associated pneumonia and ventilator-associated tracheobronchitis (74.3% and 49.4%, respectively). 63.6% of units indicated prescription solely in response to multi-drug resistant organisms. In comparison with a survey undertaken in 2014, there was a significant reduction in use of aerosolized antibiotics for prophylaxis (50.6% vs 7.7%, p < 0.05) and colonization (52.9% vs 25.3%, p < 0.05). The large majority of units (91.7%) reported only prescribing in patients with positive pulmonary cultures. Asia appeared to be an outlier, with 53.3% of units reporting empirical use. The most commonly used device was the jet nebulizer. The most commonly prescribed drugs were colistin methanesulfonate (57.6%), colistin base (41.9%) and amikacin (31.4%), although there was considerable heterogeneity across geographical areas. A significant gap exists between ESCMID clinical practice recommendations and the use of aerosolized antibiotics in clinical practice. Our findings indicate an urgent need for high-quality education to bring practice into line with evidence-based guidelines.

Mechanics of lung ventilation in a post-metamorphic salamander, Ambystoma Tigrinum.

PubMed

Simons, R S; Bennett, W O; Brainerd, E L

2000-03-01

The mechanics of lung ventilation in frogs and aquatic salamanders has been well characterized, whereas lung ventilation in terrestrial-phase (post-metamorphic) salamanders has received little attention. We used electromyography (EMG), X-ray videography, standard videography and buccal and body cavity pressure measurements to characterize the ventilation mechanics of adult (post-metamorphic) tiger salamanders (Ambystoma tigrinum). Three results emerged: (i) under terrestrial conditions or when floating at the surface of the water, adult A. tigrinum breathed through their nares using a two-stroke buccal pump; (ii) in addition to this narial two-stroke pump, adult tiger salamanders also gulped air in through their mouths using a modified two-stroke buccal pump when in an aquatic environment; and (iii) exhalation in adult tiger salamanders is active during aquatic gulping breaths, whereas exhalation appears to be passive during terrestrial breathing at rest. Active exhalation in aquatic breaths is indicated by an increase in body cavity pressure during exhalation and associated EMG activity in the lateral hypaxial musculature, particularly the M. transversus abdominis. In terrestrial breathing, no EMG activity in the lateral hypaxial muscles is generally present, and body cavity pressure decreases during exhalation. In aquatic breaths, tidal volume is larger than in terrestrial breaths, and breathing frequency is much lower (approximately 1 breath 10 min(-)(1 )versus 4-6 breaths min(-)(1)). The use of hypaxial muscles to power active exhalation in the aquatic environment may result from the need for more complete exhalation and larger tidal volumes when breathing infrequently. This hypothesis is supported by previous findings that terrestrial frogs ventilate their lungs with small tidal volumes and exhale passively, whereas aquatic frogs and salamanders use large tidal volumes and and exhale actively.

Mechanical Ventilation in Patients with the Acute Respiratory Distress Syndrome and Treated with Extracorporeal Membrane Oxygenation: Impact on Hospital and 30 Day Postdischarge Survival.

PubMed

Modrykamien, Ariel M; Hernandez, Omar O; Im, Yunhee; Walters, Ryan W; Schrader, Caleb L; Smith, Lauren E; Lima, Brian

2016-01-01

Mechanical ventilation support for acute respiratory distress syndrome (ARDS) patients involves the use of low tidal volumes and positive end-expiratory pressure. Nevertheless, the optimal ventilator strategy for ARDS patients undergoing extracorporeal membrane oxygenation (ECMO) therapy remains unknown. A retrospective analysis of a consecutive series of adult ARDS patients treated with V-V ECMO from October 2012 to May 2015 was performed. Mechanical ventilation data, as well as demographic and clinical data, were collected. We assessed the association between ventilator data and outcomes of interest. The primary outcome was hospital survival. Secondary outcome was 30 day survival posthospital discharge. Sixty-four ARDS patients were treated with ECMO. Univariate analysis showed that plateau pressure was independently associated with hospital survival. Tidal volume, positive end-expiratory pressure (PEEP), and plateau were independently associated with 30 day survival. Multivariate analysis, after controlling for covariates, revealed that a 1 unit increase in plateau pressure was associated with a 21% decrease in the odds of hospital survival (95% confidence interval [CI] = 6.39-33.42%, p = 0.007). In regards to 30 day survival postdischarge, a 1 unit increase in plateau pressure was associated with a 14.4% decrease in the odds of achieving the aforementioned outcome (95% CI = 1.75-25.4%, p = 0.027). Also, a 1 unit increase in PEEP was associated with a 36.2% decrease in the odds of 30 day survival (95% CI = 10.8-54.4%, p = 0.009). Among ARDS patients undergoing ECMO therapy, only plateau pressure is associated with hospital survival. Plateau pressure and PEEP are both associated with 30 day survival posthospital discharge.

Instituting a music listening intervention for critically ill patients receiving mechanical ventilation: Exemplars from two patient cases

PubMed Central

Heiderscheit, Annie; Chlan, Linda; Donley, Kim

2011-01-01

Music is an ideal intervention to reduce anxiety and promote relaxation in critically ill patients receiving mechanical ventilatory support. This article reviews the basis for a music listening intervention and describes two case examples with patients utilizing a music listening intervention to illustrate the implementation and use of the music listening protocol in this dynamic environment. The case examples illustrate the importance and necessity of engaging a music therapist in not only assessing the music preferences of patients, but also for implementing a music listening protocol to manage the varied and challenging needs of patients in the critical care setting. Additionally, the case examples presented in this paper demonstrate the wide array of music patients prefer and how the ease of a music listening protocol allows mechanically ventilated patients to engage in managing their own anxiety during this distressful experience. PMID:22081788

Combined Effects of Ventilation Mode and Positive End-Expiratory Pressure on Mechanics, Gas Exchange and the Epithelium in Mice with Acute Lung Injury

PubMed Central

Thammanomai, Apiradee; Hamakawa, Hiroshi; Bartolák-Suki, Erzsébet; Suki, Béla

2013-01-01

The accepted protocol to ventilate patients with acute lung injury is to use low tidal volume (VT) in combination with recruitment maneuvers or positive end-expiratory pressure (PEEP). However, an important aspect of mechanical ventilation has not been considered: the combined effects of PEEP and ventilation modes on the integrity of the epithelium. Additionally, it is implicitly assumed that the best PEEP-VT combination also protects the epithelium. We aimed to investigate the effects of ventilation mode and PEEP on respiratory mechanics, peak airway pressures and gas exchange as well as on lung surfactant and epithelial cell integrity in mice with acute lung injury. HCl-injured mice were ventilated at PEEPs of 3 and 6 cmH2O with conventional ventilation (CV), CV with intermittent large breaths (CVLB) to promote recruitment, and a new mode, variable ventilation, optimized for mice (VVN). Mechanics and gas exchange were measured during ventilation and surfactant protein (SP)-B, proSP-B and E-cadherin levels were determined from lavage and lung homogenate. PEEP had a significant effect on mechanics, gas exchange and the epithelium. The higher PEEP reduced lung collapse and improved mechanics and gas exchange but it also down regulated surfactant release and production and increased epithelial cell injury. While CVLB was better than CV, VVN outperformed CVLB in recruitment, reduced epithelial injury and, via a dynamic mechanotransduction, it also triggered increased release and production of surfactant. For long-term outcome, selection of optimal PEEP and ventilation mode may be based on balancing lung physiology with epithelial injury. PMID:23326543

Effects of staff training on the care of mechanically ventilated patients: a prospective cohort study.

PubMed

Bloos, F; Müller, S; Harz, A; Gugel, M; Geil, D; Egerland, K; Reinhart, K; Marx, G

2009-08-01

Adherence to guidelines to avoid complications associated with mechanical ventilation is often incomplete. The goal of this study was to assess whether staff training in pre-defined interventions (bundle) improves the quality of care in mechanically ventilated patients. This study was performed on a 50-bed intensive care unit of a tertiary care university hospital. Application of a ventilator bundle consisting of semirecumbent positioning, lung protective ventilation in patients with acute lung injury (ALI), ulcer prophylaxis, and deep vein thrombosis prophylaxis (DVTP) was assessed before and after staff training in post-surgical patients requiring mechanical ventilation for at least 24 h. A total of 133 patients before and 141 patients after staff training were included. Overall bundle adherence increased from 15 to 33.8% (P<0.001). Semirecumbent position was achieved in 24.9% of patient days before and 46.9% of patient days after staff training (P<0.001). Administration of DVTP increased from 89.5 to 91.5% (P=0.048). Ulcer prophylaxis of >90% was achieved in both groups. Median tidal volume in patients with ALI remained unaltered. Days on mechanical ventilation were reduced from 6 (interquartile range 2.0-15.0) to 4 (2.0-9.0) (P=0.017). Rate of ventilator-associated pneumonia (VAP), ICU length of stay, and ICU mortality remained unaffected. In patients with VAP, the median ICU length of stay was reduced by 9 days (P=0.04). Staff training by an ICU change team improved compliance to a pre-defined ventilator bundle. This led to a reduction in the days spent on mechanical ventilation, despite incomplete bundle implementation.

[Nutritional support response in critically ill patients; differences between medical and surgical patients].

PubMed

Zamora Elson, M; Serón Arbeloa, C; Labarta Monzón, L; Garrido Ramírez de Arellano, I; Lander Azcona, A; Marquina Lacueva, M I; López Claver, J C; Escós Orta, J

2012-01-01

To assess the nutritional response of a group of critically ill patients, as well as the differences in the response to nutritional support between medical and surgical patients. One-year long retrospective study including critically ill patients on artificial nutrition for 7 days. Throughout the first week, three nutritional biochemical controls were done that included albumin, prealbumin, transferrin, cholesterol, and electrolytes. Other data gathered were: nutritional risk index, age, gender, weight, height, APACHE, delay of onset of nutritional support, access route, predicted and real caloric intake, medical or surgical patient, hospital stay, duration of the central venous catheter, urinary tube, and/or mechanical ventilation, incidence and density of incidence of nosocomial infections. Sixty-three patients were studied, 30 (47%) medical and 33 (53%) surgical/trauma patients, with a usage of EN higher among medical patients (16/30, 53% vs. 5/33, 15%), PN higher among surgical patients (25/33, 76%), and mixed nutrition similar in both groups (5 medical and 3 surgical patients) (p = 0.001). There were no differences between medical and surgical patients regarding: both predicted and real caloric and nitrogenous intake, APACHE, delay of onset of nutrition, phosphorus, magnesium or glucose levels, mortality and incidence of nosocomial infections. There were no differences either in hospital stay or use of mechanical ventilation, although these tended to be lower in surgical patients. The baseline biochemical parameters did not show differences between both groups, although they were worse among surgical patients. These patients presented during the study period steady albumin levels with improvement in the remaining parameters, whereas medical patients showed a decrease in albumin and transferrin levels, steady prealbumin levels, and slightly improvement in cholesterol levels. We have observed higher usage of PN among surgical patients, which showed worse baseline nutritional biochemical parameters and responded better to nutritional support and having a trend towards shorter hospital stay and lower mechanical ventilation use than medical patients. We have not observed differences regarding the mortality or nosocomial infection.

High mortality from Guillain-Barré syndrome in Bangladesh.

PubMed

Ishaque, Tanveen; Islam, Mohammad B; Ara, Gulshan; Endtz, Hubert P; Mohammad, Quazi D; Jacobs, Bart C; Islam, Zhahirul

2017-06-01

Although Guillain-Barré syndrome (GBS) has higher incidence and poor outcome in Bangladesh, mortality from GBS in Bangladesh has never been explored before. We sought to explore the frequency, timing, and risk factors for deaths from GBS in Bangladesh. We conducted a prospective study on 407 GBS patients who were admitted to Dhaka Medical College Hospital, Dhaka, Bangladesh from 2010 to 2013. We compared deceased and alive patients to identify risk factors. Cox regression model was used to adjust for confounders. Of the 407 GBS patients, 50 (12%) died, with the median time interval between the onset of weakness and death of 18 days. Among the fatal cases, 24 (48%) were ≥40 years, 36 (72%) had a Medical Research Council sum score ≤20 at entry, 33 (66%) had a progressive phase <8 days, and 27 (54%) required ventilation support. Ten patients (20%) died due to unavailability of ventilator. The strongest risk factor for deaths was lack of ventilator support when it was required (HR: 11.9; 95% confidence interval [CI]: 4.6-30.7). Other risk factors for death included age ≥40 years (HR: 5.9; 95% CI: 2.1-16.7), mechanical ventilation (HR: 2.3; 95% CI: 1.02-5.2), longer progressive phase (>8 days) (HR: 2.06; 95% CI: 1.1-3.8), autonomic dysfunction (HR: 1.9; 95% CI: 1.05-3.6), and bulbar nerve involvement (HR: 5.4; 95% CI: 1.5-19.2). In Bangladesh, GBS is associated with higher mortality rates, which is related to lack of ventilator support, disease severity, longer progressive phase of the disease, autonomic dysfunction, and involvement of the bulbar nerves. © 2017 Peripheral Nerve Society.

Rescue therapeutic strategy combining ultra-protective mechanical ventilation with extracorporeal CO2 removal membrane in near-fatal asthma with severe pulmonary barotraumas: A case report.

PubMed

Pavot, Arthur; Mallat, Jihad; Vangrunderbeeck, Nicolas; Thevenin, Didier; Lemyze, Malcolm

2017-10-01

Mechanical ventilation of severe acute asthma is still considered a challenging issue, mainly because of the gas trapping phenomenon with the potential for life-threatening barotraumatic pulmonary complications. Herein, we describe 2 consecutive cases of near-fatal asthma for whom the recommended protective mechanical ventilation approach using low tidal volume of 6 mL/kg and small levels of PEEP was rapidly compromised by giant pneumomediastinum with extensive subcutaneousemphysema. Near fatal asthma. A rescue therapeutic strategy combining extracorporeal CO2 removal membrane with ultra-protective extremely low tidal volume (3 mL/kg) ventilation was applied. Both patients survived hospital discharge. These 2 cases indicate that ECCO2R associated with ultra-protective ventilation could be an alternative to surgery in case of life-threatening barotrauma occurring under mechanical ventilation.

Diaphragm pacing system implanted in a patient with ALS.

PubMed

Kotan, Dilcan; Kaymak, Kamil; Gündogdu, Aslı Aksoy

2016-08-10

The diaphragm pacing system (DPS) is a life quality improving operation in amyotrophic lateral sclerosis (ALS) patients who need mechanical ventilation or have chronic respiratory insufficiency. This procedure is gaining in popularity, and the number of centers implanting diaphragm pacing systems (DPS) is increasing. DPS delays the need for a ventilation machine in the early stages of Amyotrophic lateral sclerosis (ALS) disease. In this case study, we present a young female ALS patient. A DPS was implanted after respiratory insufficiency began. In the one-year follow-up period following her operation, her need for ventilatory support disappeared.

Variability in usual care mechanical ventilation for pediatric acute lung injury: the potential benefit of a lung protective computer protocol.

PubMed

Khemani, Robinder G; Sward, Katherine; Morris, Alan; Dean, J Michael; Newth, Christopher J L

2011-11-01

Although pediatric intensivists claim to embrace lung protective ventilation for acute lung injury (ALI), ventilator management is variable. We describe ventilator changes clinicians made for children with hypoxemic respiratory failure, and evaluate the potential acceptability of a pediatric ventilation protocol. This was a retrospective cohort study performed in a tertiary care pediatric intensive care unit (PICU). The study period was from January 2000 to July 2007. We included mechanically ventilated children with PaO(2)/FiO(2) (P/F) ratio less than 300. We assessed variability in ventilator management by evaluating actual changes to ventilator settings after an arterial blood gas (ABG). We evaluated the potential acceptability of a pediatric mechanical ventilation protocol we adapted from National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI) Acute Respiratory Distress Syndrome (ARDS) Network protocols by comparing actual practice changes in ventilator settings to changes that would have been recommended by the protocol. A total of 2,719 ABGs from 402 patients were associated with 6,017 ventilator settings. Clinicians infrequently decreased FiO(2), even when the PaO(2) was high (>68 mmHg). The protocol would have recommended more positive end expiratory pressure (PEEP) than was used in actual practice 42% of the time in the mid PaO(2) range (55-68 mmHg) and 67% of the time in the low PaO(2) range (<55 mmHg). Clinicians often made no change to either peak inspiratory pressure (PIP) or ventilator rate (VR) when the protocol would have recommended a change, even when the pH was greater than 7.45 with PIP at least 35 cmH(2)O. There may be lost opportunities to minimize potentially injurious ventilator settings for children with ALI. A reproducible pediatric mechanical ventilation protocol could prompt clinicians to make ventilator changes that are consistent with lung protective ventilation.

Inadequate humidification of respiratory gases during mechanical ventilation of the newborn.

PubMed Central

Tarnow-Mordi, W O; Sutton, P; Wilkinson, A R

1986-01-01

Proximal airway humidity was measured during mechanical ventilation in 14 infants using an electronic hygrometer. Values below recommended minimum humidity of adult inspired gas were recorded on 251 of 396 occasions. Inadequate humidification, largely due to inadequate proximal airway temperature, is commoner than recognised in infants receiving mechanical ventilation. PMID:3740912

The use of tracheostomy speaking valves in mechanically ventilated patients results in improved communication and does not prolong ventilation time in cardiothoracic intensive care unit patients.

PubMed

Sutt, Anna-Liisa; Cornwell, Petrea; Mullany, Daniel; Kinneally, Toni; Fraser, John F

2015-06-01

The aim of this study was to assess the effect of the introduction of in-line tracheostomy speaking valves (SVs) on duration of mechanical ventilation and time to verbal communication in patients requiring tracheostomy for prolonged mechanical ventilation in a predominantly cardiothoracic intensive care unit (ICU). We performed a retrospective preobservational-postobservational study using data from the ICU clinical information system and medical record. Extracted data included demographics, diagnoses and disease severity, mechanical ventilation requirements, and details on verbal communication and oral intake. Data were collected on 129 patients. Mean age was 59 ± 16 years, with 75% male. Demographics, case mix, and median time from intubation to tracheostomy (6 days preimplementation-postimplementation) were unchanged between timepoints. A significant decrease in time from tracheostomy to establishing verbal communication was observed (18 days preimplementation and 9 days postimplementation, P <.05). There was no difference in length of mechanical ventilation (20 days preimplementation-post) or time to decannulation (14 days preimplementation-postimplementation). No adverse events were documented in relation to the introduction of in-line SVs. In-line SVs were successfully implemented in mechanically ventilated tracheostomized patient population. This resulted in earlier verbal communication, no detrimental effect on ventilator weaning times, and no change in decannulation times. The purpose of the study was to compare tracheostomy outcomes in mechanically ventilated patients in a cardiothoracic ICU preintroduction and postintroduction of in-line SVs. It was hypothesized that in-line SVs would improve communication and swallowing specific outcomes with no increase in average time to decannulation or the number of adverse events. Copyright © 2015 Elsevier Inc. All rights reserved.

WE-AB-202-06: Correlating Lung CT HU with Transformation-Based and Xe-CT Derived Ventilation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Du, K; Patton, T; Bayouth, J

Purpose: Regional lung ventilation is useful to reduce radiation-induced function damage during lung cancer radiation therapy. Recently a new direct HU (Hounsfield unit)-based method was proposed to estimate the ventilation potential without image registration. The purpose of this study is to examine if there is a functional dependence between HU values and transformation-based or Xe-CT derived ventilation. Methods: 4DCT images acquired from 13 patients prior to radiation therapy and 4 mechanically ventilated sheep subjects which also have associated Xe-CT images were used for this analysis. Transformation-based ventilation was computed using Jacobian determinant of the transformation field between peak-exhale and peak-inhalemore » 4DCT images. Both transformation and Xe-CT derived ventilation was computed for each HU bin. Color scatter plot and cumulative histogram were used to compare and validate the direct HU-based method. Results: There was little change of the center and shape of the HU histograms between free breathing CT and 4DCT average, with or without smoothing, and between the repeated 4DCT scans. HU of −750 and −630 were found to have the greatest transformation-based ventilation for human and sheep subjects, respectively. Maximum Xe-CT derived ventilation was found to locate at HU of −600 in sheep subjects. The curve between Xe-CT ventilation and HU was noisy for tissue above HU −400, possibly due to less intensity change of Xe gas during wash-out and wash-in phases. Conclusion: Both transformation-based and Xe-CT ventilation demonstrated that lung tissues with HU values in the range of (-750, −600) HU have the maximum ventilation potential. The correlation between HU and ventilation suggests that HU might be used to help guide the ventilation calculation and make it more robust to noise and image registration errors. Research support from NIH grants CA166703 and CA166119 and a gift from Roger Koch.« less

Mild hypothermia attenuates changes in respiratory system mechanics and modifies cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation.

PubMed

Dostál, P; Senkeřík, M; Pařízková, R; Bareš, D; Zivný, P; Zivná, H; Cerný, V

2010-01-01

Hypothermia was shown to attenuate ventilator-induced lung injury due to large tidal volumes. It is unclear if the protective effect of hypothermia is maintained under less injurious mechanical ventilation in animals without previous lung injury. Tracheostomized rats were randomly allocated to non-ventilated group (group C) or ventilated groups of normothermia (group N) and mild hypothermia (group H). After two hours of mechanical ventilation with inspiratory fraction of oxygen 1.0, respiratory rate 60 min(-1), tidal volume 10 ml x kg(-1), positive end-expiratory pressure (PEEP) 2 cm H2O or immediately after tracheostomy in non-ventilated animals inspiratory pressures were recorded, rats were sacrificed, pressure-volume (PV) curve of respiratory system constructed, bronchoalveolar lavage (BAL) fluid and aortic blood samples obtained. Group N animals exhibited a higher rise in peak inspiratory pressures in comparison to group H animals. Shift of the PV curve to right, higher total protein and interleukin-6 levels in BAL fluid were observed in normothermia animals in comparison with hypothermia animals and non-ventilated controls. Tumor necrosis factor-alpha was lower in the hypothermia group in comparison with normothermia and non-ventilated groups. Mild hypothermia attenuated changes in respiratory system mechanics and modified cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation in animals without previous lung injury.

Variable versus conventional lung protective mechanical ventilation during open abdominal surgery: study protocol for a randomized controlled trial.

PubMed

Spieth, Peter M; Güldner, Andreas; Uhlig, Christopher; Bluth, Thomas; Kiss, Thomas; Schultz, Marcus J; Pelosi, Paolo; Koch, Thea; Gama de Abreu, Marcelo

2014-05-02

General anesthesia usually requires mechanical ventilation, which is traditionally accomplished with constant tidal volumes in volume- or pressure-controlled modes. Experimental studies suggest that the use of variable tidal volumes (variable ventilation) recruits lung tissue, improves pulmonary function and reduces systemic inflammatory response. However, it is currently not known whether patients undergoing open abdominal surgery might benefit from intraoperative variable ventilation. The PROtective VARiable ventilation trial ('PROVAR') is a single center, randomized controlled trial enrolling 50 patients who are planning for open abdominal surgery expected to last longer than 3 hours. PROVAR compares conventional (non-variable) lung protective ventilation (CV) with variable lung protective ventilation (VV) regarding pulmonary function and inflammatory response. The primary endpoint of the study is the forced vital capacity on the first postoperative day. Secondary endpoints include further lung function tests, plasma cytokine levels, spatial distribution of ventilation assessed by means of electrical impedance tomography and postoperative pulmonary complications. We hypothesize that VV improves lung function and reduces systemic inflammatory response compared to CV in patients receiving mechanical ventilation during general anesthesia for open abdominal surgery longer than 3 hours. PROVAR is the first randomized controlled trial aiming at intra- and postoperative effects of VV on lung function. This study may help to define the role of VV during general anesthesia requiring mechanical ventilation. Clinicaltrials.gov NCT01683578 (registered on September 3 3012).

Evaluation of a flexible bronchoscope prototype designed for bronchoscopy during mechanical ventilation: a proof-of-concept study.

PubMed

Nay, M-A; Auvet, A; Mankikian, J; Herve, V; Dequin, P-F; Guillon, A

2017-06-01

Bronchoscopy during mechanical ventilation of patients' lungs significantly affects ventilation because of partial obstruction of the tracheal tube, and may thus be omitted in the most severely ill patients. It has not previously been possible to reduce the external diameter of the bronchoscope without reducing the diameter of the suction channel, thus reducing the suctioning capacity of the device. We believed that a better-designed bronchoscope could improve the safety of bronchoscopy in patients whose lungs were ventilated. We designed a flexible bronchoscope prototype with a drumstick-shaped head consisting of a long, thin proximal portion; a short and large distal portion for camera docking; and a large suction channel throughout the length of the device. The aims of our study were to test the impact of our prototype on mechanical ventilation when inserted into the tracheal tube, and to assess suctioning capacity. We first tested the efficiency of the suction channel, and demonstrated that the suction flow of the prototype was similar to that of conventional adult bronchoscopes. We next evaluated the consequences of bronchoscopy when using the prototype on minute ventilation and intrathoracic pressures during mechanical ventilation: firstly, in vitro using a breathing simulator; and secondly, in vivo using a porcine model of pulmonary ventilation. The insertion of adult bronchoscopes into the tracheal tube immediately impaired the protective ventilation strategy employed, whereas the prototype preserved it. For the first time, we have developed an innovative flexible bronchoscope designed for bronchoscopy during invasive mechanical ventilation, that both preserved the protective ventilation strategy, and enabled efficient suction flow. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

Measurement of changes in respiratory mechanics during partial liquid ventilation using jet pulses.

PubMed

Schmalisch, Gerd; Schmidt, Mario; Proquitté, Hans; Foitzik, Bertram; Rüdiger, Mario; Wauer, Roland R

2003-05-01

To compare the changes in respiratory mechanics within the breathing cycle in healthy lungs between gas ventilation and partial liquid ventilation using a special forced-oscillation technique. Prospective animal trial. Animal laboratory in a university setting. A total of 12 newborn piglets (age, <12 hrs; mean weight, 725 g). After intubation and instrumentation, lung mechanics of the anesthetized piglets were measured by forced-oscillation technique at the end of inspiration and the end of expiration. The measurements were performed during gas ventilation and 80 mins after instillation of 30 mL/kg perfluorocarbon PF 5080. Brief flow pulses (width, 10 msec; peak flow, 16 L/min) were generated by a jet generator to measure the end-inspiratory and the end-expiratory respiratory input impedance in the frequency range of 4-32 Hz. The mechanical variables resistance, inertance, and compliance were determined by model fitting, using the method of least squares. At least in the lower frequency range, respiratory mechanics could be described adequately by an RIC single-compartment model in all piglets. During gas ventilation, the respiratory variables resistance and inertance did not differ significantly between end-inspiratory and end-expiratory measurements (mean [sd]: 4.2 [0.7] vs. 4.1 [0.6] kPa x L(-1) x sec, 30.0 [3.2] vs. 30.7 [3.1] Pa x L(-1) x sec2, respectively), whereas compliance decreased during inspiration from 14.8 (2.0) to 10.2 (2.4) mL x kPa(-1) x kg(-1) due to a slight lung overdistension. During partial liquid ventilation, the end-inspiratory respiratory mechanics was not different from the end-inspiratory respiratory mechanics measured during gas ventilation. However, in contrast to gas ventilation during partial liquid ventilation, compliance rose from 8.2 (1.0) to 13.0 (3.0) mL x kPa(-1) x kg(-1) during inspiration. During expiration, when perfluorocarbon came into the upper airways, both resistance and inertance increased considerably (mean with 95% confidence interval) by 34.3% (23.1%-45.8%) and 104.1% (96.0%-112.1%), respectively. The changes in the respiratory mechanics within the breathing cycle are considerably higher during partial liquid ventilation compared with gas ventilation. This dependence of lung mechanics from the pulmonary gas volume hampers the comparability of dynamic measurements during partial liquid ventilation, and the magnitude of these changes cannot be detected by conventional respiratory-mechanical analysis using time-averaged variables.

Lung protective mechanical ventilation and two year survival in patients with acute lung injury: prospective cohort study

PubMed Central

Colantuoni, Elizabeth; Mendez-Tellez, Pedro A; Dinglas, Victor D; Sevransky, Jonathan E; Dennison Himmelfarb, Cheryl R; Desai, Sanjay V; Shanholtz, Carl; Brower, Roy G; Pronovost, Peter J

2012-01-01

Objective To evaluate the association of volume limited and pressure limited (lung protective) mechanical ventilation with two year survival in patients with acute lung injury. Design Prospective cohort study. Setting 13 intensive care units at four hospitals in Baltimore, Maryland, USA. Participants 485 consecutive mechanically ventilated patients with acute lung injury. Main outcome measure Two year survival after onset of acute lung injury. Results 485 patients contributed data for 6240 eligible ventilator settings, as measured twice daily (median of eight eligible ventilator settings per patient; 41% of which adhered to lung protective ventilation). Of these patients, 311 (64%) died within two years. After adjusting for the total duration of ventilation and other relevant covariates, each additional ventilator setting adherent to lung protective ventilation was associated with a 3% decrease in the risk of mortality over two years (hazard ratio 0.97, 95% confidence interval 0.95 to 0.99, P=0.002). Compared with no adherence, the estimated absolute risk reduction in two year mortality for a prototypical patient with 50% adherence to lung protective ventilation was 4.0% (0.8% to 7.2%, P=0.012) and with 100% adherence was 7.8% (1.6% to 14.0%, P=0.011). Conclusions Lung protective mechanical ventilation was associated with a substantial long term survival benefit for patients with acute lung injury. Greater use of lung protective ventilation in routine clinical practice could reduce long term mortality in patients with acute lung injury. Trial registration Clinicaltrials.gov NCT00300248. PMID:22491953

Iatrogenic pneumothorax related to mechanical ventilation

PubMed Central

Hsu, Chien-Wei; Sun, Shu-Fen

2014-01-01

Pneumothorax is a potentially lethal complication associated with mechanical ventilation. Most of the patients with pneumothorax from mechanical ventilation have underlying lung diseases; pneumothorax is rare in intubated patients with normal lungs. Tension pneumothorax is more common in ventilated patients with prompt recognition and treatment of pneumothorax being important to minimize morbidity and mortality. Underlying lung diseases are associated with ventilator-related pneumothorax with pneumothoraces occurring most commonly during the early phase of mechanical ventilation. The diagnosis of pneumothorax in critical illness is established from the patients’ history, physical examination and radiological investigation, although the appearances of a pneumothorax on a supine radiograph may be different from the classic appearance on an erect radiograph. For this reason, ultrasonography is beneficial for excluding the diagnosis of pneumothorax. Respiration-dependent movement of the visceral pleura and lung surface with respect to the parietal pleura and chest wall can be easily visualized with transthoracic sonography given that the presence of air in the pleural space prevents sonographic visualization of visceral pleura movements. Mechanically ventilated patients with a pneumothorax require tube thoracostomy placement because of the high risk of tension pneumothorax. Small-bore catheters are now preferred in the majority of ventilated patients. Furthermore, if there are clinical signs of a tension pneumothorax, emergency needle decompression followed by tube thoracostomy is widely advocated. Patients with pneumothorax related to mechanical ventilation who have tension pneumothorax, a higher acute physiology and chronic health evaluation II score or PaO2/FiO2 < 200 mmHg were found to have higher mortality. PMID:24834397

Mechanical ventilation in abdominal surgery.

PubMed

Futier, E; Godet, T; Millot, A; Constantin, J-M; Jaber, S

2014-01-01

One of the key challenges in perioperative care is to reduce postoperative morbidity and mortality. Patients who develop postoperative morbidity but survive to leave hospital have often reduced functional independence and long-term survival. Mechanical ventilation provides a specific example that may help us to shift thinking from treatment to prevention of postoperative complications. Mechanical ventilation in patients undergoing surgery has long been considered only as a modality to ensure gas exchange while allowing maintenance of anesthesia with delivery of inhaled anesthetics. Evidence is accumulating, however, suggesting an association between intraoperative mechanical ventilation strategy and postoperative pulmonary function and clinical outcome in patients undergoing abdominal surgery. Non-protective ventilator settings, especially high tidal volume (VT) (>10-12mL/kg) and the use of very low level of positive end-expiratory pressure (PEEP) (PEEP<5cmH2O) or no PEEP, may cause alveolar overdistension and repetitive tidal recruitment leading to ventilator-associated lung injury in patients with healthy lungs. Stimulated by previous findings in patients with acute respiratory distress syndrome, the use of lower tidal volume ventilation is becoming increasingly more common in the operating room. However, lowering tidal volume, though important, is only part of the overall multifaceted approach of lung protective mechanical ventilation. In this review, we aimed at providing the most recent and relevant clinical evidence regarding the use of mechanical ventilation in patients undergoing abdominal surgery. Copyright © 2014 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.

Novel analysis of 4DCT imaging quantifies progressive increases in anatomic dead space during mechanical ventilation in mice.

PubMed

Kim, Elizabeth H; Preissner, Melissa; Carnibella, Richard P; Samarage, Chaminda R; Bennett, Ellen; Diniz, Marcio A; Fouras, Andreas; Zosky, Graeme R; Jones, Heather D

2017-09-01

Increased dead space is an important prognostic marker in early acute respiratory distress syndrome (ARDS) that correlates with mortality. The cause of increased dead space in ARDS has largely been attributed to increased alveolar dead space due to ventilation/perfusion mismatching and shunt. We sought to determine whether anatomic dead space also increases in response to mechanical ventilation. Mice received intratracheal lipopolysaccharide (LPS) or saline and mechanical ventilation (MV). Four-dimensional computed tomography (4DCT) scans were performed at onset of MV and after 5 h of MV. Detailed measurements of airway volumes and lung tidal volumes were performed using image analysis software. The forced oscillation technique was used to obtain measures of airway resistance, tissue damping, and tissue elastance. The ratio of airway volumes to total tidal volume increased significantly in response to 5 h of mechanical ventilation, regardless of LPS exposure, and airways demonstrated significant variation in volumes over the respiratory cycle. These findings were associated with an increase in tissue elastance (decreased lung compliance) but without changes in tidal volumes. Airway volumes increased over time with exposure to mechanical ventilation without a concomitant increase in tidal volumes. These findings suggest that anatomic dead space fraction increases progressively with exposure to positive pressure ventilation and may represent a pathological process. NEW & NOTEWORTHY We demonstrate that anatomic dead space ventilation increases significantly over time in mice in response to mechanical ventilation. The novel functional lung-imaging techniques applied here yield sensitive measures of airway volumes that may have wide applications. Copyright © 2017 the American Physiological Society.

[Nasal CPAP versus mechanical ventilation in 28 to 32-week preterm infants with early surfactant administration].

PubMed

Pérez, Luis Alfonso; González, Diana Marcela; Álvarez, Karen Margarita de Jesús; Díaz-Martínez, Luis Alfonso

2014-01-01

Continuous positive airway pressure (CPAP) is useful in low birth weight infants with respiratory distress, but it is not known if it is a better alternative to mechanical ventilation after early pulmonary surfactant administration. To compare the incidence of adverse events in 28 to 32-week newborns with respiratory distress managed with mechanical ventilation or CPAP after early surfactant administration. In total, 176 newborns were treated with CPAP and 147 with mechanical ventilation, all with Apgar scores >3 at five minutes and without apnea. The incidence of CPAP failure was 6.5% (95% CI: 11.3-22.8%); 29 patients died: 7 with CPAP (4.0%) and 22 with mechanical ventilation (15.0%, p<0.001). The relative risk of dying with CPAP versus mechanical ventilation was 0.27 (95% CI: 0.12-0.61), but after adjusting for confounding factors, CPAP use did not imply a higher risk of dying (RR=0.60; 95% CI: 0.29-1.24). Mechanical ventilation fatality rate was 5.70 (95% CI: 3.75-8.66) deaths/1,000 days-patient, while with CPAP it was 1.37 (95% CI: 0.65-2.88, p<0.001). Chronic lung disease incidence was lower with CPAP than with mechanical ventilation (RR=0.71; 95% CI: 0.54-0.96), as were intracranial hemorrhage (RR=0.28, 95% CI: 0.09-0.84) and sepsis (RR=0.67; 95%CI: 0.52-0.86), and it was similar for air leaks (RR=2.51; 95% CI: 0.83-7.61) and necrotizing enterocolitis (RR=1.68, 95% CI: 0.59-4.81). CPAP exposure of premature infants with respiratory distress syndrome is protective against chronic lung disease, intraventricular hemorrhage and sepsis compared to mechanical ventilation. No differences were observed regarding air leak syndrome or death.

Recurrent Recruitment Manoeuvres Improve Lung Mechanics and Minimize Lung Injury during Mechanical Ventilation of Healthy Mice

PubMed Central

Reiss, Lucy Kathleen; Kowallik, Anke; Uhlig, Stefan

2011-01-01

Introduction Mechanical ventilation (MV) of mice is increasingly required in experimental studies, but the conditions that allow stable ventilation of mice over several hours have not yet been fully defined. In addition, most previous studies documented vital parameters and lung mechanics only incompletely. The aim of the present study was to establish experimental conditions that keep these parameters within their physiological range over a period of 6 h. For this purpose, we also examined the effects of frequent short recruitment manoeuvres (RM) in healthy mice. Methods Mice were ventilated at low tidal volume VT = 8 mL/kg or high tidal volume VT = 16 mL/kg and a positive end-expiratory pressure (PEEP) of 2 or 6 cmH2O. RM were performed every 5 min, 60 min or not at all. Lung mechanics were followed by the forced oscillation technique. Blood pressure (BP), electrocardiogram (ECG), heart frequency (HF), oxygen saturation and body temperature were monitored. Blood gases, neutrophil-recruitment, microvascular permeability and pro-inflammatory cytokines in bronchoalveolar lavage (BAL) and blood serum as well as histopathology of the lung were examined. Results MV with repetitive RM every 5 min resulted in stable respiratory mechanics. Ventilation without RM worsened lung mechanics due to alveolar collapse, leading to impaired gas exchange. HF and BP were affected by anaesthesia, but not by ventilation. Microvascular permeability was highest in atelectatic lungs, whereas neutrophil-recruitment and structural changes were strongest in lungs ventilated with high tidal volume. The cytokines IL-6 and KC, but neither TNF nor IP-10, were elevated in the BAL and serum of all ventilated mice and were reduced by recurrent RM. Lung mechanics, oxygenation and pulmonary inflammation were improved by increased PEEP. Conclusions Recurrent RM maintain lung mechanics in their physiological range during low tidal volume ventilation of healthy mice by preventing atelectasis and reduce the development of pulmonary inflammation. PMID:21935418

National Trends (2009-2013) for Palliative Care Utilization for Patients Receiving Prolonged Mechanical Ventilation.

PubMed

Chatterjee, Kshitij; Goyal, Abhinav; Kakkera, Krishna; Harrington, Sarah; Corwin, Howard L

2018-05-04

Patients requiring mechanical ventilation have high morbidity and mortality. Providing palliative care services has been suggested as a way to improve comprehensive management of critically ill patients. We examined the trend in the utilization of palliative care among adults who require prolonged mechanical ventilation. Primary objectives were to determine the trend in palliative care utilization over time, predictors for palliative care utilization, and palliative care impact on hospital length of stay. Retrospective, cross-sectional study. The National Inpatient Sample data between 2009 and 2013 was used for this study. Adults (age ≥ 18 yr) who underwent prolonged mechanical ventilation (≥ 96 consecutive hr) were studied. Palliative care and mechanical ventilation were identified using the corresponding International Classification of Diseases, 9th revision, Clinical Modification, codes. A total of 1,751,870 hospitalizations with prolonged mechanical ventilation were identified between 2009 and 2013. The utilization of palliative care increased yearly from 6.5% in 2009 to 13.1% in 2013 (p < 0.001). Among the mechanically ventilated patients who died, palliative care increased from 15.9% in 2009 to 33.3% in 2013 (p < 0.001). Median hospital length of stay for patients with and without palliative care was 13 and 17 days, respectively (p < 0.001). Patients discharged to either short- or long-term care facilities had a shorter length of stay if palliative care was provided (15 vs 19 d; p < 0.001). The factors associated with a higher palliative care utilization included older age, malignancy, larger hospitals in urban areas, and teaching hospitals. Non-Caucasian race was associated with lower palliative care utilization. Among patients who undergo prolonged mechanical ventilation, palliative care utilization is increasing, particularly in patients who die during hospitalization. Using palliative care for mechanically ventilated patients who are discharged to either short- or long-term care facilities is associated with a shorter hospital length of stay.

pRotective vEntilation with veno-venouS lung assisT in respiratory failure: A protocol for a multicentre randomised controlled trial of extracorporeal carbon dioxide removal in patients with acute hypoxaemic respiratory failure.

PubMed

McNamee, J J; Gillies, M A; Barrett, N A; Agus, A M; Beale, R; Bentley, A; Bodenham, A; Brett, S J; Brodie, D; Finney, S J; Gordon, A J; Griffiths, M; Harrison, D; Jackson, C; McDowell, C; McNally, C; Perkins, G D; Tunnicliffe, W; Vuylsteke, A; Walsh, T S; Wise, M P; Young, D; McAuley, D F

2017-05-01

One of the few interventions to demonstrate improved outcomes for acute hypoxaemic respiratory failure is reducing tidal volumes when using mechanical ventilation, often termed lung protective ventilation. Veno-venous extracorporeal carbon dioxide removal (vv-ECCO 2 R) can facilitate reducing tidal volumes. pRotective vEntilation with veno-venouS lung assisT (REST) is a randomised, allocation concealed, controlled, open, multicentre pragmatic trial to determine the clinical and cost-effectiveness of lower tidal volume mechanical ventilation facilitated by vv-ECCO 2 R in patients with acute hypoxaemic respiratory failure. Patients requiring intubation and mechanical ventilation for acute hypoxaemic respiratory failure will be randomly allocated to receive either vv-ECCO 2 R and lower tidal volume mechanical ventilation or standard care with stratification by recruitment centre. There is a need for a large randomised controlled trial to establish whether vv-ECCO 2 R in acute hypoxaemic respiratory failure can allow the use of a more protective lung ventilation strategy and is associated with improved patient outcomes.

Optimal ventilation of the anesthetized pediatric patient.

PubMed

Feldman, Jeffrey M

2015-01-01

Mechanical ventilation of the pediatric patient is challenging because small changes in delivered volume can be a significant fraction of the intended tidal volume. Anesthesia ventilators have traditionally been poorly suited to delivering small tidal volumes accurately, and pressure-controlled ventilation has become used commonly when caring for pediatric patients. Modern anesthesia ventilators are designed to deliver small volumes accurately to the patient's airway by compensating for the compliance of the breathing system and delivering tidal volume independent of fresh gas flow. These technology advances provide the opportunity to implement a lung-protective ventilation strategy in the operating room based upon control of tidal volume. This review will describe the capabilities of the modern anesthesia ventilator and the current understanding of lung-protective ventilation. An optimal approach to mechanical ventilation for the pediatric patient is described, emphasizing the importance of using bedside monitors to optimize the ventilation strategy for the individual patient.

Noninvasive Mechanical Ventilation in Acute Ventilatory Failure: Rationale and Current Applications.

PubMed

Esquinas, Antonio M; Benhamou, Maly Oron; Glossop, Alastair J; Mina, Bushra

2017-12-01

Noninvasive ventilation plays a pivotal role in acute ventilator failure and has been shown, in certain disease processes such as acute exacerbation of chronic obstructive pulmonary disease, to prevent and shorten the duration of invasive mechanical ventilation, reducing the risks and complications associated with it. The application of noninvasive ventilation is relatively simple and well tolerated by patients and in the right setting can change the course of their illness. Copyright © 2017 Elsevier Inc. All rights reserved.

One-year trajectories of care and resource utilization for recipients of prolonged mechanical ventilation: a cohort study.

PubMed

Unroe, Mark; Kahn, Jeremy M; Carson, Shannon S; Govert, Joseph A; Martinu, Tereza; Sathy, Shailaja J; Clay, Alison S; Chia, Jessica; Gray, Alice; Tulsky, James A; Cox, Christopher E

2010-08-03

Growing numbers of critically ill patients receive prolonged mechanical ventilation. Little is known about the patterns of care as patients transition from acute care hospitals to postacute care facilities or about the associated resource utilization. To describe 1-year trajectories of care and resource utilization for patients receiving prolonged mechanical ventilation. 1-year prospective cohort study. 5 intensive care units at Duke University Medical Center, Durham, North Carolina. 126 patients receiving prolonged mechanical ventilation (defined as ventilation for >or=4 days with tracheostomy placement or ventilation for >or=21 days without tracheostomy), as well as their 126 surrogates and 54 intensive care unit physicians, enrolled consecutively over 1 year. Patients and surrogates were interviewed in the hospital, as well as 3 and 12 months after discharge, to determine patient survival, functional status, and facility type and duration of postdischarge care. Physicians were interviewed in the hospital to elicit prognoses. Institutional billing records were used to assign costs for acute care, outpatient care, and interfacility transportation. Medicare claims data were used to assign costs for postacute care. 103 (82%) hospital survivors had 457 separate transitions in postdischarge care location (median, 4 transitions [interquartile range, 3 to 5 transitions]), including 68 patients (67%) who were readmitted at least once. Patients spent an average of 74% (95% CI, 68% to 80%) of all days alive in a hospital or postacute care facility or receiving home health care. At 1 year, 11 patients (9%) had a good outcome (alive with no functional dependency), 33 (26%) had a fair outcome (alive with moderate dependency), and 82 (65%) had a poor outcome (either alive with complete functional dependency [4 patients; 21%] or dead [56 patients; 44%]). Patients with poor outcomes were older, had more comorbid conditions, and were more frequently discharged to a postacute care facility than patients with either fair or good outcomes (P < 0.05 for all). The mean cost per patient was $306,135 (SD, $285,467), and total cohort cost was $38.1 million, for an estimated $3.5 million per independently functioning survivor at 1 year. The results of this single-center study may not be applicable to other centers. Patients receiving prolonged mechanical ventilation have multiple transitions of care, resulting in substantial health care costs and persistent, profound disability. The optimism of surrogate decision makers should be balanced by discussions of these outcomes when considering a course of prolonged life support. None.

Automatic control of arterial carbon dioxide tension in mechanically ventilated patients.

PubMed

Fernando, Tyrone; Cade, John; Packer, John

2002-12-01

This paper presents a method of controlling the arterial carbon dioxide tension of patients receiving mechanical ventilation. Controlling of the CO2 tension is achieved by regulating the ventilator initiated breath frequency and also volume per breath.

Personal care assistants' experiences of caring for people on home mechanical ventilation.

PubMed

Israelsson-Skogsberg, Åsa; Lindahl, Berit

2017-03-01

The aim of this study was to describe personal care assistants' (PCA) experiences of working with a ventilator-assisted person at home. Data were collected from fifteen audiotaped semistructured interviews with PCAs supporting a child or adult using home mechanical ventilation (HMV). Thirteen women and two men participated; their working experience with HMV users ranged from one to 17 years (median 6 years). Data were subjected to qualitative content analysis in an inductive and interpretive manner. Five categories emerged from the data: Being part of a complex work situation; Taking on a multidimensional responsibility; Caring carried out in someone's home; Creating boundaries in an environment with indistinct limits; and Being close to another's body and soul. The participants felt very close to the person they worked with, both physically and emotionally. They had a great responsibility and therefore a commensurate need for support, guidance and a well-functioning organisation around the HMV user. There is international consensus that advanced home care will continue to expand and personal care assistance is key in this development. We suggest that one way to move forward for PCAs working with HMV users is to create multiprofessional teams led by a key-person who coordinates the individual needs. More research is needed within this area from a broad perspective including the HMV-assisted persons, relatives, personal care assistants and management organisations. © 2016 Nordic College of Caring Science.

Chest ultrasounds to guide manual reexpansion of a postoperative pulmonary atelectasis: a case report.

PubMed

Cavaliere, F; Biasucci, D; Costa, R; Soave, M; Addabbo, G; Proietti, R

2011-07-01

Reexpansion of a pulmonary atelectasis is often difficult, even after removing possible causes of bronchial obstruction. Chest ultrasounds, inexpensive and readily available at the patient bedside, may offer valuable support to guide recruitment maneuvers. We report the case of a 57-year-old woman that developed a complete collapse of the left lung seven days after undergoing an intestinal resection for perforation. A mucous plug occluding the main bronchus was removed with bronchoscopy, but persistent hypoxemia required mechanical ventilation; 24 hours later, an attempt to wean the patient from the ventilator failed. Chest X-rays revealed the persistence of a partial collapse of the left inferior lobe associated with a pleural effusion. A chest ultrasound confirmed the presence of a lung consolidation and of a modest pleural effusion. Manual reexpansion was then attempted, and ventilatory pressures as well as the duration of forced inspirations were based on real-time ultrasound images. Complete reexpansion was achieved within a few minutes and confirmed by chest X-ray. The patient was weaned from mechanical ventilation on the same day and discharged from ICU three days later.

Potential clinical application of surface electromyography as indicator of neuromuscular recovery during weaning tests after organophosphate poisoning.

PubMed

Sánchez, Maria Bernarda Salazar; Valdivieso, Alher Mauricio Hernández; Villanueva, Miguel Ángel Mañanas; Salazar, Andrés Felipe Zuluaga

2017-01-01

This study aimed to explore the usefulness of measuring respiratory muscle activity in mechanically ventilated patients suffering from acute organophosphate poisoning, with a view towards providing complementary information to determine the best time to suspend ventilatory support. Surface electromyography in respiratory muscles (diaphragm, external intercostal and sternocleidomastoid muscles) was recorded in a young man affected by self-poisoning with an unknown amount of parathion to determine the muscle activity level during several weaning attempts from mechanical ventilation. The energy distribution of each surface electromyography signal frequency, the synchronization between machine and patient and between muscles, acetylcholinesterase enzyme activity, and work of breathing and rapid shallow breathing indices were calculated in each weaning attempt. The work of breathing and rapid shallow breathing indices were not correlated with the failure/success of the weaning attempt. The diaphragm gradually increased its engagement with ventilation, achieving a maximal response that correlated with successful weaning and maximal acetylcholinesterase enzyme activity; in contrast, the activity of accessory respiratory muscles showed an opposite trend.

Potential clinical application of surface electromyography as indicator of neuromuscular recovery during weaning tests after organophosphate poisoning

PubMed Central

Sánchez, Maria Bernarda Salazar; Valdivieso, Alher Mauricio Hernández; Villanueva, Miguel Ángel Mañanas; Salazar, Andrés Felipe Zuluaga

2017-01-01

This study aimed to explore the usefulness of measuring respiratory muscle activity in mechanically ventilated patients suffering from acute organophosphate poisoning, with a view towards providing complementary information to determine the best time to suspend ventilatory support. Surface electromyography in respiratory muscles (diaphragm, external intercostal and sternocleidomastoid muscles) was recorded in a young man affected by self-poisoning with an unknown amount of parathion to determine the muscle activity level during several weaning attempts from mechanical ventilation. The energy distribution of each surface electromyography signal frequency, the synchronization between machine and patient and between muscles, acetylcholinesterase enzyme activity, and work of breathing and rapid shallow breathing indices were calculated in each weaning attempt. The work of breathing and rapid shallow breathing indices were not correlated with the failure/success of the weaning attempt. The diaphragm gradually increased its engagement with ventilation, achieving a maximal response that correlated with successful weaning and maximal acetylcholinesterase enzyme activity; in contrast, the activity of accessory respiratory muscles showed an opposite trend. PMID:28977266

Poor Adherence to Lung-Protective Mechanical Ventilation in Pediatric Acute Respiratory Distress Syndrome.

PubMed

Ward, Shan L; Quinn, Carson M; Valentine, Stacey L; Sapru, Anil; Curley, Martha A Q; Willson, Douglas F; Liu, Kathleen D; Matthay, Michael A; Flori, Heidi R

2016-10-01

To determine the frequency of low-tidal volume ventilation in pediatric acute respiratory distress syndrome and assess if any demographic or clinical factors improve low-tidal volume ventilation adherence. Descriptive post hoc analysis of four multicenter pediatric acute respiratory distress syndrome studies. Twenty-six academic PICU. Three hundred fifteen pediatric acute respiratory distress syndrome patients. All patients who received conventional mechanical ventilation at hours 0 and 24 of pediatric acute respiratory distress syndrome who had data to calculate ideal body weight were included. Two cutoff points for low-tidal volume ventilation were assessed: less than or equal to 6.5 mL/kg of ideal body weight and less than or equal to 8 mL/kg of ideal body weight. Of 555 patients, we excluded 240 for other respiratory support modes or missing data. The remaining 315 patients had a median PaO2-to-FIO2 ratio of 140 (interquartile range, 90-201), and there were no differences in demographics between those who did and did not receive low-tidal volume ventilation. With tidal volume cutoff of less than or equal to 6.5 mL/kg of ideal body weight, the adherence rate was 32% at hour 0 and 33% at hour 24. A low-tidal volume ventilation cutoff of tidal volume less than or equal to 8 mL/kg of ideal body weight resulted in an adherence rate of 58% at hour 0 and 60% at hour 24. Low-tidal volume ventilation use was no different by severity of pediatric acute respiratory distress syndrome nor did adherence improve over time. At hour 0, overweight children were less likely to receive low-tidal volume ventilation less than or equal to 6.5 mL/kg ideal body weight (11% overweight vs 38% nonoverweight; p = 0.02); no difference was noted by hour 24. Furthermore, in the overweight group, using admission weight instead of ideal body weight resulted in misclassification of up to 14% of patients as receiving low-tidal volume ventilation when they actually were not. Low-tidal volume ventilation is underused in the first 24 hours of pediatric acute respiratory distress syndrome. Age, Pediatric Risk of Mortality-III, and pediatric acute respiratory distress syndrome severity were not associated with improved low-tidal volume ventilation adherence nor did adherence improve over time. Overweight children were less likely to receive low-tidal volume ventilation strategies in the first day of illness.

Procedures and Standards for Residential Ventilation System Commissioning: An Annotated Bibliography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stratton, J. Chris; Wray, Craig P.

2013-04-01

Beginning with the 2008 version of Title 24, new homes in California must comply with ANSI/ASHRAE Standard 62.2-2007 requirements for residential ventilation. Where installed, the limited data available indicate that mechanical ventilation systems do not always perform optimally or even as many codes and forecasts predict. Commissioning such systems when they are installed or during subsequent building retrofits is a step towards eliminating deficiencies and optimizing the tradeoff between energy use and acceptable IAQ. Work funded by the California Energy Commission about a decade ago at Berkeley Lab documented procedures for residential commissioning, but did not focus on ventilation systems.more » Since then, standards and approaches for commissioning ventilation systems have been an active area of work in Europe. This report describes our efforts to collect new literature on commissioning procedures and to identify information that can be used to support the future development of residential-ventilation-specific procedures and standards. We recommend that a standardized commissioning process and a commissioning guide for practitioners be developed, along with a combined energy and IAQ benefit assessment standard and tool, and a diagnostic guide for estimating continuous pollutant emission rates of concern in residences (including a database that lists emission test data for commercially-available labeled products).« less

Airway Strain during Mechanical Ventilation in an Intact Animal Model

PubMed Central

Sinclair, Scott E.; Molthen, Robert C.; Haworth, Steve T.; Dawson, Christopher A.; Waters, Christopher M.

2007-01-01

Rationale: Mechanical ventilation with large tidal volumes causes ventilator-induced lung injury in animal models. Little direct evidence exists regarding the deformation of airways in vivo during mechanical ventilation, or in the presence of positive end-expiratory pressure (PEEP). Objectives: To measure airway strain and to estimate airway wall tension during mechanical ventilation in an intact animal model. Methods: Sprague-Dawley rats were anesthetized and mechanically ventilated with tidal volumes of 6, 12, and 25 cm3/kg with and without 10–cm H2O PEEP. Real-time tantalum bronchograms were obtained for each condition, using microfocal X-ray imaging. Images were used to calculate circumferential and longitudinal airway strains, and on the basis of a simplified mathematical model we estimated airway wall tensions. Measurements and Main Results: Circumferential and longitudinal airway strains increased with increasing tidal volume. Levels of mechanical strain were heterogeneous throughout the bronchial tree. Circumferential strains were higher in smaller airways (less than 800 μm). Airway size did not influence longitudinal strain. When PEEP was applied, wall tensions increased more rapidly than did strain levels, suggesting that a “strain limit” had been reached. Airway collapse was not observed under any experimental condition. Conclusions: Mechanical ventilation results in significant airway mechanical strain that is heterogeneously distributed in the uninjured lung. The magnitude of circumferential but not axial strain varies with airway diameter. Airways exhibit a “strain limit” above which an abrupt dramatic rise in wall tension is observed. PMID:17626911

Benefits of Manometer in Non-Invasive Ventilatory Support.

PubMed

Lacerda, Rodrigo Silva; de Lima, Fernando Cesar Anastácio; Bastos, Leonardo Pereira; Fardin Vinco, Anderson; Schneider, Felipe Britto Azevedo; Luduvico Coelho, Yves; Fernandes, Heitor Gomes Costa; Bacalhau, João Marcus Ramos; Bermudes, Igor Matheus Simonelli; da Silva, Claudinei Ferreira; da Silva, Luiza Paterlini; Pezato, Rogério

2017-12-01

Introduction Effective ventilation during cardiopulmonary resuscitation (CPR) is essential to reduce morbidity and mortality rates in cardiac arrest. Hyperventilation during CPR reduces the efficiency of compressions and coronary perfusion. Problem How could ventilation in CPR be optimized? The objective of this study was to evaluate non-invasive ventilator support using different devices. The study compares the regularity and intensity of non-invasive ventilation during simulated, conventional CPR and ventilatory support using three distinct ventilation devices: a standard manual resuscitator, with and without airway pressure manometer, and an automatic transport ventilator. Student's t-test was used to evaluate statistical differences between groups. P values <.05 were regarded as significant. Peak inspiratory pressure during ventilatory support and CPR was significantly increased in the group with manual resuscitator without manometer when compared with the manual resuscitator with manometer support (MS) group or automatic ventilator (AV) group. The study recommends for ventilatory support the use of a manual resuscitator equipped with MS or AVs, due to the risk of reduction in coronary perfusion pressure and iatrogenic thoracic injury during hyperventilation found using manual resuscitator without manometer. Lacerda RS , de Lima FCA , Bastos LP , Vinco AF , Schneider FBA , Coelho YL , Fernandes HGC , Bacalhau JMR , Bermudes IMS , da Silva CF , da Silva LP , Pezato R . Benefits of manometer in non-invasive ventilatory support. Prehosp Disaster Med. 2017;32(6):615-620.

Efficacy of respiratory muscle training in weaning of mechanical ventilation in patients with mechanical ventilation for 48hours or more: A Randomized Controlled Clinical Trial.

PubMed

Sandoval Moreno, L M; Casas Quiroga, I C; Wilches Luna, E C; García, A F

2018-02-02

To evaluate the efficacy of respiratory muscular training in the weaning of mechanical ventilation and respiratory muscle strength in patients on mechanical ventilation of 48hours or more. Randomized controlled trial of parallel groups, double-blind. Ambit: Intensive Care Unit of a IV level clinic in the city of Cali. 126 patients in mechanical ventilation for 48hours or more. The experimental group received daily a respiratory muscle training program with treshold, adjusted to 50% of maximal inspiratory pressure, additional to standard care, conventional received standard care of respiratory physiotherapy. MAIN INTEREST VARIABLES: weaning of mechanical ventilation. Other variables evaluated: respiratory muscle strength, requirement of non-invasive mechanical ventilation and frequency of reintubation. intention-to-treat analysis was performed with all variables evaluated and analysis stratified by sepsis condition. There were no statistically significant differences in the median weaning time of the MV between the groups or in the probability of extubation between groups (HR: 0.82 95% CI: 0.55-1.20 P=.29). The maximum inspiratory pressure was increased in the experimental group on average 9.43 (17.48) cmsH20 and in the conventional 5.92 (11.90) cmsH20 (P=.48). The difference between the means of change in maximal inspiratory pressure was 0.46 (P=.83 95%CI -3.85 to -4.78). respiratory muscle training did not demonstrate efficacy in the reduction of the weaning period of mechanical ventilation nor in the increase of respiratory muscle strength in the study population. Registered study at ClinicalTrials.gov (NCT02469064). Copyright © 2017 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

Can routine surveillance samples from tracheal aspirate predict bacterial flora in cases of ventilator-associated pneumonia?

PubMed

Lampati, L; Maggioni, E; Langer, M; Malacarne, P; Mozzo, R; Pesenti, A; Fumagalli, R

2009-10-01

The aim of this study was to investigate the hypothesis that periodical sampling of the tracheo-bronchial tree in the absence of clinical suspicion of pneumonia is useful to identify bacteria responsible for subsequent late ventilator associated pneumonia (VAP). This was a retrospective observational human study carried out in two medical-surgical intensive care units of two different hospitals. From January 1999 to December 2000, 559 patients, who received invasive respiratory support for more than 48 hours, were screened. Tracheal aspiration (TA) was performed once or twice weekly in all mechanically ventilated patients. The microbiological findings from TA surveillance cultures done in the eight days before suspicion of VAP were compared to those isolated from the positive diagnostic samples done for late onset VAP (after more than four days of mechanical ventilation). The sensitivity, specificity, and positive/negative predictive values of the ability of the surveillance sample to anticipate the VAP pathogen were calculated. Among the microorganisms isolated from TA, 68% were retrieved from diagnostic samples. All VAP pathogens previously isolated were from 43% of the TA samples. If TA was collected 2-4 days before the clinical diagnosis of VAP, pathogens were detected in 58% of samples. In contrast, only 27% were collected more than four days earlier (P<0.05). The positive predictive values for Pseudomonas aeruginosa and methicillin resistant Staphylococcus aureus from routine TA samples were 92% and 90%, respectively. The negative predictive values for Pseudomonas aeruginosa and methicillin resistant Staphylococcus aureus from routine TA samples were 75% and 89%, respectively. TA cultures in ventilated patients may help to predict pathogens. Early detection may lead to earlier treatment in long term ventilated patients when VAP is suspected.

The effects of exogenous surfactant administration on ventilation-induced inflammation in mouse models of lung injury.

PubMed

Puntorieri, Valeria; Hiansen, Josh Qua; McCaig, Lynda A; Yao, Li-Juan; Veldhuizen, Ruud A W; Lewis, James F

2013-11-20

Mechanical ventilation (MV) is an essential supportive therapy for acute lung injury (ALI); however it can also contribute to systemic inflammation. Since pulmonary surfactant has anti-inflammatory properties, the aim of the study was to investigate the effect of exogenous surfactant administration on ventilation-induced systemic inflammation. Mice were randomized to receive an intra-tracheal instillation of a natural exogenous surfactant preparation (bLES, 50 mg/kg) or no treatment as a control. MV was then performed using the isolated and perfused mouse lung (IPML) set up. This model allowed for lung perfusion during MV. In experiment 1, mice were exposed to mechanical ventilation only (tidal volume =20 mL/kg, 2 hours). In experiment 2, hydrochloric acid or air was instilled intra-tracheally four hours before applying exogenous surfactant and ventilation (tidal volume =5 mL/kg, 2 hours). For both experiments, exogenous surfactant administration led to increased total and functional surfactant in the treated groups compared to the controls. Exogenous surfactant administration in mice exposed to MV only did not affect peak inspiratory pressure (PIP), lung IL-6 levels and the development of perfusate inflammation compared to non-treated controls. Acid injured mice exposed to conventional MV showed elevated PIP, lung IL-6 and protein levels and greater perfusate inflammation compared to air instilled controls. Instillation of exogenous surfactant did not influence the development of lung injury. Moreover, exogenous surfactant was not effective in reducing the concentration of inflammatory cytokines in the perfusate. The data indicates that exogenous surfactant did not mitigate ventilation-induced systemic inflammation in our models. Future studies will focus on altering surfactant composition to improve its immuno-modulating activity.

Stockpiling Ventilators for Influenza Pandemics.

PubMed

Huang, Hsin-Chan; Araz, Ozgur M; Morton, David P; Johnson, Gregory P; Damien, Paul; Clements, Bruce; Meyers, Lauren Ancel

2017-06-01

In preparing for influenza pandemics, public health agencies stockpile critical medical resources. Determining appropriate quantities and locations for such resources can be challenging, given the considerable uncertainty in the timing and severity of future pandemics. We introduce a method for optimizing stockpiles of mechanical ventilators, which are critical for treating hospitalized influenza patients in respiratory failure. As a case study, we consider the US state of Texas during mild, moderate, and severe pandemics. Optimal allocations prioritize local over central storage, even though the latter can be deployed adaptively, on the basis of real-time needs. This prioritization stems from high geographic correlations and the slightly lower treatment success assumed for centrally stockpiled ventilators. We developed our model and analysis in collaboration with academic researchers and a state public health agency and incorporated it into a Web-based decision-support tool for pandemic preparedness and response.

Fifty Years of Research in ARDS. Respiratory Mechanics in Acute Respiratory Distress Syndrome.

PubMed

Henderson, William R; Chen, Lu; Amato, Marcelo B P; Brochard, Laurent J

2017-10-01

Acute respiratory distress syndrome is a multifactorial lung injury that continues to be associated with high levels of morbidity and mortality. Mechanical ventilation, although lifesaving, is associated with new iatrogenic injury. Current best practice involves the use of small Vt, low plateau and driving pressures, and high levels of positive end-expiratory pressure. Collectively, these interventions are termed "lung-protective ventilation." Recent investigations suggest that individualized measurements of pulmonary mechanical variables rather than population-based ventilation prescriptions may be used to set the ventilator with the potential to improve outcomes beyond those achieved with standard lung protective ventilation. This review outlines the measurement and application of clinically applicable pulmonary mechanical concepts, such as plateau pressures, driving pressure, transpulmonary pressures, stress index, and measurement of strain. In addition, the concept of the "baby lung" and the utility of dynamic in addition to static measures of pulmonary mechanical variables are discussed.

Equation Discovery for Model Identification in Respiratory Mechanics of the Mechanically Ventilated Human Lung

NASA Astrophysics Data System (ADS)

Ganzert, Steven; Guttmann, Josef; Steinmann, Daniel; Kramer, Stefan

Lung protective ventilation strategies reduce the risk of ventilator associated lung injury. To develop such strategies, knowledge about mechanical properties of the mechanically ventilated human lung is essential. This study was designed to develop an equation discovery system to identify mathematical models of the respiratory system in time-series data obtained from mechanically ventilated patients. Two techniques were combined: (i) the usage of declarative bias to reduce search space complexity and inherently providing the processing of background knowledge. (ii) A newly developed heuristic for traversing the hypothesis space with a greedy, randomized strategy analogical to the GSAT algorithm. In 96.8% of all runs the applied equation discovery system was capable to detect the well-established equation of motion model of the respiratory system in the provided data. We see the potential of this semi-automatic approach to detect more complex mathematical descriptions of the respiratory system from respiratory data.

Ventilatory strategies and supportive care in acute respiratory distress syndrome.

PubMed

Luks, Andrew M

2013-11-01

While antiviral therapy is an important component of care in patients with the acute respiratory distress syndrome (ARDS) following influenza infection, it is not sufficient to ensure good outcomes, and additional measures are usually necessary. Patients usually receive high levels of supplemental oxygen to counteract the hypoxemia resulting from severe gas exchange abnormalities. Many patients also receive invasive mechanical ventilation for support for oxygenation, while in resource-poor settings, supplemental oxygen via face mask may be the only available intervention. Patients with ARDS receiving mechanical ventilation should receive lung-protective ventilation, whereby tidal volume is decreased to 6 ml/kg of their predicted weight and distending pressures are maintained ≤ 30 cm H2 O, as well as increased inspired oxygen concentrations and positive end-expiratory pressure (PEEP) to prevent atelectasis and support oxygenation. While these measures are sufficient in most patients, a minority develop refractory hypoxemia and may receive additional therapies, including prone positioning, inhaled vasodilators, extracorporeal membrane oxygenation, recruitment maneuvers followed by high PEEP, and neuromuscular blockade, although recent data suggest that this last option may be warranted earlier in the clinical course before development of refractory hypoxemia. Application of these "rescue strategies" is complicated by the lack of guidance in the literature regarding implementation. While much attention is devoted to these strategies, clinicians must not lose sight of simple interventions that affect patient outcomes including head of bed elevation, prophylaxis against venous thromboembolism and gastrointestinal bleeding, judicious use of fluids in the post-resuscitative phase, and a protocol-based approach to sedation and spontaneous breathing trials. © 2013 Blackwell Publishing Ltd.

Pneumococcal pneumonia - Are the new severity scores more accurate in predicting adverse outcomes?

PubMed

Ribeiro, C; Ladeira, I; Gaio, A R; Brito, M C

2013-01-01

The site-of-care decision is one of the most important factors in the management of patients with community-acquired pneumonia. The severity scores are validated prognostic tools for community-acquired pneumonia mortality and treatment site decision. The aim of this paper was to compare the discriminatory power of four scores - the classic PSI and CURB65 ant the most recent SCAP and SMART-COP - in predicting major adverse events: death, ICU admission, need for invasive mechanical ventilation or vasopressor support in patients admitted with pneumococcal pneumonia. A five year retrospective study of patients admitted for pneumococcal pneumonia. Patients were stratified based on admission data and assigned to low-, intermediate-, and high-risk classes for each score. Results were obtained comparing low versus non-low risk classes. We studied 142 episodes of hospitalization with 2 deaths and 10 patients needing mechanical ventilation and vasopressor support. The majority of patients were classified as low risk by all scores - we found high negative predictive values for all adverse events studied, the most negative value corresponding to the SCAP score. The more recent scores showed better accuracy for predicting ICU admission and need for ventilation or vasopressor support (mostly for the SCAP score with higher AUC values for all adverse events). The rate of all adverse outcomes increased directly with increasing risk class in all scores. The new gravity scores appear to have a higher discriminatory power in all adverse events in our study, particularly, the SCAP score. Copyright © 2012 Sociedade Portuguesa de Pneumologia. Published by Elsevier España. All rights reserved.

[Treatment of acute respiratory distress syndrome using pressure and volume controlled ventilation with lung protective strategy].

PubMed

Ge, Ying; Wan, Yong; Wang, Da-qing; Su, Xiao-lin; Li, Jun-ying; Chen, Jing

2004-07-01

To investigate the significance and effect of pressure controlled ventilation (PCV) as well as volume controlled ventilation (VCV) by lung protective strategy on respiratory mechanics, blood gas analysis and hemodynamics in patients with acute respiratory distress syndrome (ARDS). Fifty patients with ARDS were randomly divided into PCV and VCV groups with permissive hypercapnia and open lung strategy. Changes in respiratory mechanics, blood gas analysis and hemodynamics were compared between two groups. Peak inspiration pressure (PIP) in PCV group was significantly lower than that in VCV group, while mean pressure of airway (MPaw) was significantly higher than that in VCV after 24 hours mechanical ventilation. After 24 hours mechanical ventilation, there were higher central venous pressure (CVP) and slower heart rate (HR) in two groups, CVP was significantly higher in VCV compared with PCV, and PCV group had slower HR than VCV group, the two groups had no differences in mean blood pressure (MBP) at various intervals. All patients showed no ventilator-induced lung injury. Arterial blood oxygenations were obviously improved in two groups after 24 hours mechanical ventilation, PCV group had better partial pressure of oxygen in artery (PaO2) than VCV group. Both PCV and VCV can improve arterial blood oxygenations, prevent ventilator-induced lung injury, and have less disturbance in hemodynamic parameters. PCV with lung protective ventilatory strategy should be early use for patients with ARDS.

Clinical factors associated with success of proportional assist ventilation in the acute phase of critical illness: pilot study.

PubMed

Delgado, M; Zavala, E; Tomás, R; Fernandez, R

2014-03-01

Proportional assist ventilation plus (PAV+) applies pressure depending on the patient's inspiratory effort, automatically adjusting flow and volume assist to changes in respiratory mechanics. We aimed to assess the clinical factors associated with the success of PAV+ as first-line support in the acute phase of critical illness. A prospective cohort study was carried out. Mechanically ventilated patients>24h were switched from assist-control ventilation to PAV+ as soon as they regained spontaneous breathing activity. PAV+ was set to deliver the highest assistance. We compared patients in whom PAV+ succeeded versus those in whom it failed. PAV+ succeeded in 12 (63%) patients, but failed in 7 (37%) due to tachypnea (n=4), hypercapnia (n=2), and metabolic acidosis (n=1), but without statistical significance. Both groups had similar clinical parameters. On the day of inclusion, total work of breathing per breath was lower in the successful PAV+ group (WOBTOT: 0.95 [0.8-1.35] vs. 1.6 [1.4-1.8] J/L; P<.007). The area under the ROC curve was 0.89 ± 0.08 for WOBTOT. The best cut-off for predicting PAV+ success was WOBTOT<1.4 J/L (sensitivity: 1 [0.7-1], specificity: 0.6 [0.4-0.6], PPV: 0.7 [0.5-0.7], and NPV: 1 [0.6-1]). PAV+ proved feasible as first-line ventilatory support in 63% of the patients, mostly in individuals without extreme derangements in WOBTOT. Tachypnea and hypercapnia were the clinical factors associated with failure, though statistical significance was not reached. Copyright © 2013 Elsevier España, S.L. and SEMICYUC. All rights reserved.

Simulation of late inspiratory rise in airway pressure during pressure support ventilation.

PubMed

Yu, Chun-Hsiang; Su, Po-Lan; Lin, Wei-Chieh; Lin, Sheng-Hsiang; Chen, Chang-Wen

2015-02-01

Late inspiratory rise in airway pressure (LIRAP, Paw/ΔT) caused by inspiratory muscle relaxation or expiratory muscle contraction is frequently seen during pressure support ventilation (PSV), although the modulating factors are unknown. We investigated the effects of respiratory mechanics (normal, obstructive, restrictive, or mixed), inspiratory effort (-2, -8, or -15 cm H2O), flow cycle criteria (5-40% peak inspiratory flow), and duration of inspiratory muscle relaxation (0.18-0.3 s) on LIRAP during PSV using a lung simulator and 4 types of ventilators. LIRAP occurred with all lung models when inspiratory effort was medium to high and duration of inspiratory muscle relaxation was short. The normal lung model was associated with the fastest LIRAP, whereas the obstructive lung model was associated with the slowest. Unless lung mechanics were normal or mixed, LIRAP was unlikely to occur when inspiratory effort was low. Different ventilators were also associated with differences in LIRAP speed. Except for within the restrictive lung model, changes in flow cycle level did not abolish LIRAP if inspiratory effort was medium to high. Increased duration of inspiratory relaxation also led to the elimination of LIRAP. Simulation of expiratory muscle contraction revealed that LIRAP occurred only when expiratory muscle contraction occurred sometime after the beginning of inspiration. Our simulation study reveals that both respiratory resistance and compliance may affect LIRAP. Except for under restrictive lung conditions, LIRAP is unlikely to be abolished by simply lowering flow cycle criteria when inspiratory effort is strong and relaxation time is rapid. LIRAP may be caused by expiratory muscle contraction when it occurs during inspiration. Copyright © 2015 by Daedalus Enterprises.

Ventilatory support in critically ill hematology patients with respiratory failure

PubMed Central

2012-01-01

Introduction Hematology patients admitted to the ICU frequently experience respiratory failure and require mechanical ventilation. Noninvasive mechanical ventilation (NIMV) may decrease the risk of intubation, but NIMV failure poses its own risks. Methods To establish the impact of ventilatory management and NIMV failure on outcome, data from a prospective, multicenter, observational study were analyzed. All hematology patients admitted to one of the 34 participating ICUs in a 17-month period were followed up. Data on demographics, diagnosis, severity, organ failure, and supportive therapies were recorded. A logistic regression analysis was done to evaluate the risk factors associated with death and NIVM failure. Results Of 450 patients, 300 required ventilatory support. A diagnosis of congestive heart failure and the initial use of NIMV significantly improved survival, whereas APACHE II score, allogeneic transplantation, and NIMV failure increased the risk of death. The risk factors associated with NIMV success were age, congestive heart failure, and bacteremia. Patients with NIMV failure experienced a more severe respiratory impairment than did those electively intubated. Conclusions NIMV improves the outcome of hematology patients with respiratory insufficiency, but NIMV failure may have the opposite effect. A careful selection of patients with rapidly reversible causes of respiratory failure may increase NIMV success. PMID:22827955

Resistive pressure of a condenser humidifier in mechanically ventilated patients.

PubMed

Manthous, C A; Schmidt, G A

1994-11-01

Heat and moisture exchangers (or "nose" humidifiers) are commonly used to aid in the humidification of inspired gases of mechanically ventilated patients. These devices add resistance to the ventilator circuit that has heretofore not been quantified in critically ill patients. Accordingly, we determined the resistive pressures associated with new and old (but < 24 hrs in the circuit) humidifiers in 23 critically ill, mechanically ventilated patients. Prospective study. Adult medical and surgical intensive care units at a university center. Twenty-three critically ill, mechanically ventilated patients using a condenser humidifier between the wye and the endotracheal tube. Peak and plateau airway pressures were determined with the humidifier in place. These measurements were repeated without the humidifier, then after insertion of a fresh humidifier into the circuit. In five patients, measurements were repeated after humidifiers had remained in place for a full 24 hrs. The new humidifiers increased the resistive pressure of the ventilator circuit by 4.8 +/- 2.6 cm H2O compared with no humidifier (p < .01) and had a mean resistance of 4.2 +/- 1.5 cm H2O/L/sec. Old humidifiers increased resistive pressure by 6.3 +/- 3.6 cm H2O compared with no humidifier (p < .01) and had a mean resistance of 5.1 +/- 1.8 cm H2O/L/sec. The resistive pressure doubled from 3.4 +/- 1.2 to 7.0 +/- 1.8 cm H2O (p < .01) in five patients in whom the humidifiers were left in the ventilator circuit for a full 24 hrs. The humidifier adds a significant resistance to the ventilator circuit which may lead to incorrect assessment of respiratory system mechanics, to inappropriate therapy (e.g., bronchodilators), or to difficulty in weaning from mechanical ventilation.

Intraoperative protective mechanical ventilation for prevention of postoperative pulmonary complications: a comprehensive review of the role of tidal volume, positive end-expiratory pressure, and lung recruitment maneuvers.

PubMed

Güldner, Andreas; Kiss, Thomas; Serpa Neto, Ary; Hemmes, Sabrine N T; Canet, Jaume; Spieth, Peter M; Rocco, Patricia R M; Schultz, Marcus J; Pelosi, Paolo; Gama de Abreu, Marcelo

2015-09-01

Postoperative pulmonary complications are associated with increased morbidity, length of hospital stay, and mortality after major surgery. Intraoperative lung-protective mechanical ventilation has the potential to reduce the incidence of postoperative pulmonary complications. This review discusses the relevant literature on definition and methods to predict the occurrence of postoperative pulmonary complication, the pathophysiology of ventilator-induced lung injury with emphasis on the noninjured lung, and protective ventilation strategies, including the respective roles of tidal volumes, positive end-expiratory pressure, and recruitment maneuvers. The authors propose an algorithm for protective intraoperative mechanical ventilation based on evidence from recent randomized controlled trials.

A quasi-experimental, before-after trial examining the impact of an emergency department mechanical ventilator protocol on clinical outcomes and lung-protective ventilation in acute respiratory distress syndrome

PubMed Central

Fuller, Brian M.; Ferguson, Ian T.; Mohr, Nicholas M.; Drewry, Anne M.; Palmer, Christopher; Wessman, Brian T.; Ablordeppey, Enyo; Keeperman, Jacob; Stephens, Robert J.; Briscoe, Cristopher C.; Kolomiets, Angelina A.; Hotchkiss, Richard S.; Kollef, Marin H.

2017-01-01

Objective To evaluate the impact of an emergency department (ED) mechanical ventilation protocol on clinical outcomes and adherence to lung-protective ventilation in patients with acute respiratory distress syndrome (ARDS). Design Quasi-experimental, before-after trial. Setting ED and intensive care units (ICU) of an academic center. Patients Mechanically ventilated ED patients experiencing ARDS while in the ED or after admission to the ICU. Interventions An ED ventilator protocol which targeted parameters in need of quality improvement, as identified by prior work: 1) lung-protective tidal volume; 2) appropriate setting of positive end-expiratory pressure (PEEP); 3) oxygen weaning; and 4) head-of-bed elevation. Measurements and Main Results A total of 229 patients (186 pre-intervention group, 43 intervention group) were studied. In the ED, the intervention was associated with significant changes (P < 0.01 for all) in tidal volume, PEEP, respiratory rate, oxygen administration, and head-of-bed elevation. There was a reduction in ED tidal volume from 8.1 mL/kg PBW (7.0 – 9.1) to 6.4 mL/kg PBW (6.1 – 6.7), and an increase in lung-protective ventilation from 11.1% to 61.5%, P < 0.01. The intervention was associated with a reduction in mortality from 54.8% to 39.5% (OR 0.38, 95% CI 0.17 – 0.83, P = 0.02), and a 3.9 day increase in ventilator-free days, P = 0.01. Conclusions This before-after study of mechanically ventilated patients with ARDS demonstrates that implementing a mechanical ventilator protocol in the ED is feasible, and associated with improved clinical outcomes. PMID:28157140

A Quasi-Experimental, Before-After Trial Examining the Impact of an Emergency Department Mechanical Ventilator Protocol on Clinical Outcomes and Lung-Protective Ventilation in Acute Respiratory Distress Syndrome.

PubMed

Fuller, Brian M; Ferguson, Ian T; Mohr, Nicholas M; Drewry, Anne M; Palmer, Christopher; Wessman, Brian T; Ablordeppey, Enyo; Keeperman, Jacob; Stephens, Robert J; Briscoe, Cristopher C; Kolomiets, Angelina A; Hotchkiss, Richard S; Kollef, Marin H

2017-04-01

To evaluate the impact of an emergency department mechanical ventilation protocol on clinical outcomes and adherence to lung-protective ventilation in patients with acute respiratory distress syndrome. Quasi-experimental, before-after trial. Emergency department and ICUs of an academic center. Mechanically ventilated emergency department patients experiencing acute respiratory distress syndrome while in the emergency department or after admission to the ICU. An emergency department ventilator protocol which targeted variables in need of quality improvement, as identified by prior work: 1) lung-protective tidal volume, 2) appropriate setting of positive end-expiratory pressure, 3) oxygen weaning, and 4) head-of-bed elevation. A total of 229 patients (186 preintervention group, 43 intervention group) were studied. In the emergency department, the intervention was associated with significant changes (p < 0.01 for all) in tidal volume, positive end-expiratory pressure, respiratory rate, oxygen administration, and head-of-bed elevation. There was a reduction in emergency department tidal volume from 8.1 mL/kg predicted body weight (7.0-9.1) to 6.4 mL/kg predicted body weight (6.1-6.7) and an increase in lung-protective ventilation from 11.1% to 61.5%, p value of less than 0.01. The intervention was associated with a reduction in mortality from 54.8% to 39.5% (odds ratio, 0.38; 95% CI, 0.17-0.83; p = 0.02) and a 3.9 day increase in ventilator-free days, p value equals to 0.01. This before-after study of mechanically ventilated patients with acute respiratory distress syndrome demonstrates that implementing a mechanical ventilator protocol in the emergency department is feasible and associated with improved clinical outcomes.

Setting individualized positive end-expiratory pressure level with a positive end-expiratory pressure decrement trial after a recruitment maneuver improves oxygenation and lung mechanics during one-lung ventilation.

PubMed

Ferrando, Carlos; Mugarra, Ana; Gutierrez, Andrea; Carbonell, Jose Antonio; García, Marisa; Soro, Marina; Tusman, Gerardo; Belda, Francisco Javier

2014-03-01

We investigated whether individualized positive end-expiratory pressure (PEEP) improves oxygenation, ventilation, and lung mechanics during one-lung ventilation compared with standardized PEEP. Thirty patients undergoing thoracic surgery were randomly allocated to the study or control group. Both groups received an alveolar recruitment maneuver at the beginning and end of one-lung ventilation. After the alveolar recruitment maneuver, the control group had their lungs ventilated with a 5 cm·H2O PEEP, while the study group had their lungs ventilated with an individualized PEEP level determined by a PEEP decrement trial. Arterial blood samples, lung mechanics, and volumetric capnography were recorded at multiple timepoints throughout the procedure. The individualized PEEP values in study group were higher than the standardized PEEP values (10 ± 2 vs 5 cm·H2O; P < 0.001). In both groups, arterial oxygenation decreased when bilateral-lung ventilation was switched to one-lung ventilation and increased after the alveolar recruitment maneuver. During one-lung ventilation, oxygenation was maintained in the study group but decreased in the control group. After one-lung ventilation, arterial oxygenation was significantly higher in the study group (306 vs 231 mm·Hg, P = 0.007). Static compliance decreased in both groups when bilateral-lung ventilation was switched to one-lung ventilation. Static compliance increased significantly only in the study group (P < 0.001) after the alveolar recruitment maneuver and optimal PEEP adjustment. The alveolar recruitment maneuver did not decrease cardiac index in any patient. During one-lung ventilation, the improvements in oxygenation and lung mechanics after an alveolar recruitment maneuver were better preserved by ventilation by using individualized PEEP with a PEEP decrement trial than with a standardized 5 cm·H2O of PEEP.

Massive gas insufflation without effect on esophageal reflectometry profiles

NASA Astrophysics Data System (ADS)

Raphael, David T.; Arnaudov, Dimiter; Benbassat, Maxim

2003-10-01

Time-domain acoustic reflectometry generates a ``one-dimensional'' image of the interior of a cavity in the form of an area-distance profile. After patient intubation with a breathing tube, the characteristic reflectometry profile consists of a constant-area segment corresponding to the length of the tube, followed either by a rapid increase in the area beyond the carina (lung) or by a sudden decrease in the area to zero (esophagus). In the cardiac arrest setting, during mistaken placement of the breathing tube into the esophagus, followed by aggressive manual ventilation, is it possible to markedly distend the esophagus, such that the esophageal profile looks like a tracheal profile? With approval of the USC IUCAC Committee, an animal study was conducted with anesthetized, tracheally intubated, and mechanically ventilated dogs. With a separate breathing tube in the esophagus, aggressive esophageal ventilation (comparable to that seen in the cardiopulmonary resuscitation setting) was accomplished with a manual resuscitation bag. A Benson Hood Labs two-microphone reflectometer was used to obtain esophageal profiles with and without the above ventilation. In this pilot study, there was no significant esophageal distention as a result of the above ventilation. [Research supported by the Alfred E. Mann Institute.

Lung and Diaphragm Damage at Varying Oxygen Levels and Ventilator Modes Pst Hemorrhagic

DTIC Science & Technology

2011-12-20

scavenging in prenatal neonates (Vento et al., 2009). In addition, Lee et al. found that mice breathing 40% oxygen had elevated tissue levels of...pulmonary mechanics. Another limitation was that we did not administer any fluid resuscitation to correct the hemorrhagic shock during mechanical... resuscitation . Testing only a controlled mode of mechanical ventilation was a limitation to our study. Most mechanical ventilations offer a mixed mode of

Mechanical Ventilation during Extracorporeal Membrane Oxygenation in Patients with Acute Severe Respiratory Failure.

PubMed

Zhang, Zhongheng; Gu, Wan-Jie; Chen, Kun; Ni, Hongying

2017-01-01

Conventionally, a substantial number of patients with acute respiratory failure require mechanical ventilation (MV) to avert catastrophe of hypoxemia and hypercapnia. However, mechanical ventilation per se can cause lung injury, accelerating the disease progression. Extracorporeal membrane oxygenation (ECMO) provides an alternative to rescue patients with severe respiratory failure that conventional mechanical ventilation fails to maintain adequate gas exchange. The physiology behind ECMO and its interaction with MV were reviewed. Next, we discussed the timing of ECMO initiation based on the risks and benefits of ECMO. During the running of ECMO, the protective ventilation strategy can be employed without worrying about catastrophic hypoxemia and carbon dioxide retention. There is a large body of evidence showing that protective ventilation with low tidal volume, high positive end-expiratory pressure, and prone positioning can provide benefits on mortality outcome. More recently, there is an increasing popularity on the use of awake and spontaneous breathing for patients undergoing ECMO, which is thought to be beneficial in terms of rehabilitation.

Mechanical Ventilation during Extracorporeal Membrane Oxygenation in Patients with Acute Severe Respiratory Failure

PubMed Central

Gu, Wan-Jie; Chen, Kun; Ni, Hongying

2017-01-01

Conventionally, a substantial number of patients with acute respiratory failure require mechanical ventilation (MV) to avert catastrophe of hypoxemia and hypercapnia. However, mechanical ventilation per se can cause lung injury, accelerating the disease progression. Extracorporeal membrane oxygenation (ECMO) provides an alternative to rescue patients with severe respiratory failure that conventional mechanical ventilation fails to maintain adequate gas exchange. The physiology behind ECMO and its interaction with MV were reviewed. Next, we discussed the timing of ECMO initiation based on the risks and benefits of ECMO. During the running of ECMO, the protective ventilation strategy can be employed without worrying about catastrophic hypoxemia and carbon dioxide retention. There is a large body of evidence showing that protective ventilation with low tidal volume, high positive end-expiratory pressure, and prone positioning can provide benefits on mortality outcome. More recently, there is an increasing popularity on the use of awake and spontaneous breathing for patients undergoing ECMO, which is thought to be beneficial in terms of rehabilitation. PMID:28127231

[Lung protective ventilation - pathophysiology and diagnostics].

PubMed

Uhlig, Stefan; Frerichs, Inéz

2008-06-01

Mechanical ventilation may lead to lung injury depending on the ventilatory settings (e.g. pressure amplitudes, endexpiratory pressures, frequency) and the length of mechanical ventilation. Particularly in the inhomogeneously injured lungs of ARDS patients, alveolar overextension results in volutrauma, cyclic opening and closure of alveolar units in atelectrauma. Particularly important appears to be the fact that these processes may also cause biotrauma, i.e. the ventilator-induced hyperactivation of inflammatory responses in the lung. These side effects are reduced, but not eliminated with the currently recommended ventilation strategy with a tidal volume of 6 ml/kg idealized body weight. It is our hope that in the future optimization of ventilator settings will be facilated by bedside monitoring of novel indices of respiratory mechanics such as the stress index or the Slice technique, and by innovative real-time imaging technologies such as electrical impedance tomography.

Preferences for Life-Sustaining Treatments and Associations With Accurate Prognostic Awareness and Depressive Symptoms in Terminally Ill Cancer Patients' Last Year of Life.

PubMed

Tang, Siew Tzuh; Wen, Fur-Hsing; Hsieh, Chia-Hsun; Chou, Wen-Chi; Chang, Wen-Cheng; Chen, Jen-Shi; Chiang, Ming-Chu

2016-01-01

The stability of life-sustaining treatment (LST) preferences at end of life (EOL) has been established. However, few studies have assessed preferences more than two times. Furthermore, associations of LST preferences with modifiable variables of accurate prognostic awareness, physician-patient EOL care discussions, and depressive symptoms have been investigated in cross-sectional studies only. To explore longitudinal changes in LST preferences and their associations with accurate prognostic awareness, physician-patient EOL care discussions, and depressive symptoms in terminally ill cancer patients' last year. LST preferences (cardiopulmonary resuscitation, intensive care unit [ICU] care, intubation, and mechanical ventilation) were measured approximately every two weeks. Changes in LST preferences and their associations with independent variables were examined by hierarchical generalized linear modeling with logistic regression. Participants (n = 249) predominantly rejected cardiopulmonary resuscitation, ICU care, intubation, and mechanical ventilation at EOL without significant changes as death approached. Patients with inaccurate prognostic awareness were significantly more likely than those with accurate understanding to prefer ICU care, intubation, and mechanical ventilation than to reject these LSTs. Patients with more severe depressive symptoms were less likely to prefer ICU care and to be undecided about wanting ICU care and mechanical ventilation than to reject such LSTs. LST preferences were not associated with physician-patient EOL care discussions, which were rare in our sample. LST preferences are stable in cancer patients' last year. Facilitating accurate prognostic awareness and providing adequate psychological support may counteract the increasing trend for aggressive EOL care and minimize emotional distress during EOL care decisions. Copyright © 2016 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Practice of mechanical ventilation in cardiac arrest patients and effects of targeted temperature management: A substudy of the targeted temperature management trial.

PubMed

Harmon, Matthew B A; van Meenen, David M P; van der Veen, Annelou L I P; Binnekade, Jan M; Dankiewicz, Josef; Ebner, Florian; Nielsen, Niklas; Pelosi, Paolo; Schultz, Marcus J; Horn, Janneke; Friberg, Hans; Juffermans, Nicole P

2018-05-12

Mechanical ventilation practices in patients with cardiac arrest are not well described. Also, the effect of temperature on mechanical ventilation settings is not known. The aims of this study were 1) to describe practice of mechanical ventilation and its relation with outcome 2) to determine effects of different target temperatures strategies (33 °C versus 36 °C) on mechanical ventilation settings. This is a substudy of the TTM-trial in which unconscious survivors of a cardiac arrest due to a cardiac cause were randomized to two TTM strategies, 33 °C (TTM33) and 36 °C (TTM36). Mechanical ventilation data were obtained at three time points: 1) before TTM; 2) at the end of TTM (before rewarming) and 3) after rewarming. Logistic regression was used to determine an association between mechanical ventilation variables and outcome. Repeated-measures mixed modelling was performed to determine the effect of TTM on ventilation settings. Mechanical ventilation data was available for 567 of the 950 TTM patients. Of these, 81% was male with a mean (SD) age of 64 (12) years. At the end of TTM median tidal volume was 7.7 ml/kg predicted body weight (PBW)(6.4-8.7) and 60% of patients were ventilated with a tidal volume ≤ 8 ml/kg PBW. Median PEEP was 7.7cmH 2 O (6.4-8.7) and mean driving pressure was 14.6 cmH 2 O (±4.3). The median FiO 2 fraction was 0.35 (0.30-0.45). Multivariate analysis showed an independent relationship between increased respiratory rate and 28-day mortality. TTM33 resulted in lower end-tidal CO 2 (Pgroup = 0.0003) and higher alveolar dead space fraction (Pgroup = 0.003) compared to TTM36, while PCO 2 levels and respiratory minute volume were similar between groups. In the majority of the cardiac arrest patients, protective ventilation settings are applied, including low tidal volumes and driving pressures. High respiratory rate was associated with mortality. TTM33 results in lower end-tidal CO 2 levels and a higher alveolar dead space fraction compared to TTTM36. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Intra-aortic balloon pump combined with mechanical ventilation for treating patients aged > 60 years in cardiogenic shock: Retrospective analysis

PubMed Central

Liu, Hongwei; Wu, Xueping; Zhao, Xiaoning; Zhu, Ping

2016-01-01

Objective To examine if mechanical ventilation with positive end-expiratory pressure (PEEP) combined with intra-aortic balloon pump (IABP) provided a better outcome than IABP alone for the treatment of cardiogenic shock after acute myocardial infarction in patients aged > 60 years. Methods This was a retrospective analysis of data from patients in cardiogenic shock, refractory to pharmacological therapy and treated at a geriatric coronary care unit. Results Sixty-two patients were eligible for study inclusion: 33 received IABP alone; 29 received IABP combined with mechanical ventilation. Patients in the IABP + mechanical ventilation group had lower mean arterial blood pressure (BP), systolic BP and partial pressure of oxygen compared with the IABP group, indicating worse cardiac and pulmonary function. In addition, higher rates of pulmonary infection and renal insufficiency were observed in the IABP + mechanical ventilation group than in the IABP group. A statistically significant improvement of left ventricular function before and after treatment was observed in the IABP + mechanical ventilation group, but not in the IABP group. Pulmonary infection and renal insufficiency were risk factors for all-cause in-hospital mortality; successful revascularization was a negative risk factor. There was no between-group difference in survival. Conclusion Mechanical ventilation with an appropriate level of PEEP appears to enhance the beneficial effects of IABP on left ventricular function for patients in cardiogenic shock. PMID:27020597

Protective mechanical ventilation in United Kingdom critical care units: A multicentre audit

PubMed Central

Martin, Matthew J; Richardson, Neil; Bourdeaux, Christopher P

2016-01-01

Lung protective ventilation is becoming increasingly used for all critically ill patients being mechanically ventilated on a mandatory ventilator mode. Compliance with the universal application of this ventilation strategy in intensive care units in the United Kingdom is unknown. This 24-h audit of ventilation practice took place in 16 intensive care units in two regions of the United Kingdom. The mean tidal volume for all patients being ventilated on a mandatory ventilator mode was 7.2(±1.4) ml kg−1 predicted body weight and overall compliance with low tidal volume ventilation (≤6.5 ml kg−1 predicted body weight) was 34%. The mean tidal volume for patients ventilated with volume-controlled ventilation was 7.0(±1.2) ml kg−1 predicted body weight and 7.9(±1.8) ml kg−1 predicted body weight for pressure-controlled ventilation (P < 0.0001). Overall compliance with recommended levels of positive end-expiratory pressure was 72%. Significant variation in practice existed both at a regional and individual unit level. PMID:28979556

Protective mechanical ventilation in United Kingdom critical care units: A multicentre audit.

PubMed

Newell, Christopher P; Martin, Matthew J; Richardson, Neil; Bourdeaux, Christopher P

2017-05-01

Lung protective ventilation is becoming increasingly used for all critically ill patients being mechanically ventilated on a mandatory ventilator mode. Compliance with the universal application of this ventilation strategy in intensive care units in the United Kingdom is unknown. This 24-h audit of ventilation practice took place in 16 intensive care units in two regions of the United Kingdom. The mean tidal volume for all patients being ventilated on a mandatory ventilator mode was 7.2(±1.4) ml kg -1 predicted body weight and overall compliance with low tidal volume ventilation (≤6.5 ml kg -1 predicted body weight) was 34%. The mean tidal volume for patients ventilated with volume-controlled ventilation was 7.0(±1.2) ml kg -1 predicted body weight and 7.9(±1.8) ml kg -1 predicted body weight for pressure-controlled ventilation ( P  < 0.0001). Overall compliance with recommended levels of positive end-expiratory pressure was 72%. Significant variation in practice existed both at a regional and individual unit level.

Respirator triggering of electron-beam computed tomography (EBCT): differences in dynamic changes between augmented ventilation and controlled mechanical ventilation

NASA Astrophysics Data System (ADS)

Recheis, Wolfgang A.; Kleinsasser, Axel; Schuster, Antonius H.; Loeckinger, Alexander; Frede, Thomas; Springer, Peter; Hoermann, Christoph; zur Nedden, Dieter

2000-04-01

The purpose was to evaluate differences in dynamic changes of the lung aeration (air-tissue ratio) between augmented modes of ventilation (AMV) and controlled mechanical ventilation (CMV) in normal subjects. 4 volunteers, ventilated with the different respirator protocols via face mask, were scanned using the EBCT in the 50 ms mode. A software analyzed the respirator's digitized pressure and volume signals of two subsequent ventilation phases. Using these values it was possible to calculate the onset of inspiration or expiration of the next respiratory phase. The calculated starting point was then used to trigger the EBCT. The dynamic changes of air- tissue ratios were evaluated in three separate regions: a ventral, an intermediate and a dorsal area. AMV results in increase of air-tissue ratio in the dorsal lung area due to the active contraction of the diaphragm, whereas CMV results in a more pronounced increase in air-tissue ratio of the ventral lung area. This study gives further insight into the dynamic changes of the lung's biomechanics by comparing augmented ventilation and controlled mechanical ventilation in the healthy proband.

Effects of music intervention on physiological stress response and anxiety level of mechanically ventilated patients in China: a randomised controlled trial.

PubMed

Han, Lin; Li, Ji P; Sit, Janet W H; Chung, Loretta; Jiao, Zuo Y; Ma, Wei G

2010-04-01

To examine the effects of music intervention on the physiological stress response and the anxiety level among mechanically ventilated patients in intensive care unit. Despite the fact that previous studies have found music interventions to be effective in stress and anxiety reduction, effects of music on the Chinese population are inconclusive and warranted systematic study to evaluate its effect fully for a different Asian culture. A randomised placebo-controlled trial. A total of 137 patients receiving mechanical ventilation were randomly assigned to either music listening group, headphone group or control group. Outcome measures included the Chinese version of Spielberger State-Trait Anxiety Scale and physiological parameters (heart rate, respiratory rate, saturation of oxygen and blood pressure). Comparison of mean differences (pretest score-posttest score) showed significant differences in heart rate, respiratory rate, systolic blood pressure and diastolic blood pressure as well as the Chinese version of Spielberger State-Trait Anxiety Scale, but not in SaO(2) among the three groups (ranging from p < 0.001 to p = 0.007), of which greater mean differences were found in music listening group. A significant reduction in physiological stress response (heart rate and respiratory rate) over time was found in music listening group (p < 0.001 for both variables) and a significant increase in heart rate and respiratory rate over time in control group (p < 0.001 and p = 0.032), with no significant change over time in headphone group. Within group pretest-posttest comparison of the Chinese version of Spielberger State-Trait Anxiety Scale demonstrated a significant reduction in anxiety for the music listening group (p < 0.001) and headphone group (p < 0.001) but not the control group. Our findings confirm that short-term therapeutic effects of music listening results in substantial reduction in physiological stress responses arising from anxiety in mechanically ventilated patients. Music as a non-pharmacological nursing intervention can be used as complementary adjunct in the care of patients with low-energy states who tire easily, such as those requiring mechanical ventilator support.

Natural ventilation for the prevention of airborne contagion.

PubMed

Escombe, A Roderick; Oeser, Clarissa C; Gilman, Robert H; Navincopa, Marcos; Ticona, Eduardo; Pan, William; Martínez, Carlos; Chacaltana, Jesus; Rodríguez, Richard; Moore, David A J; Friedland, Jon S; Evans, Carlton A

2007-02-01

Institutional transmission of airborne infections such as tuberculosis (TB) is an important public health problem, especially in resource-limited settings where protective measures such as negative-pressure isolation rooms are difficult to implement. Natural ventilation may offer a low-cost alternative. Our objective was to investigate the rates, determinants, and effects of natural ventilation in health care settings. The study was carried out in eight hospitals in Lima, Peru; five were hospitals of "old-fashioned" design built pre-1950, and three of "modern" design, built 1970-1990. In these hospitals 70 naturally ventilated clinical rooms where infectious patients are likely to be encountered were studied. These included respiratory isolation rooms, TB wards, respiratory wards, general medical wards, outpatient consulting rooms, waiting rooms, and emergency departments. These rooms were compared with 12 mechanically ventilated negative-pressure respiratory isolation rooms built post-2000. Ventilation was measured using a carbon dioxide tracer gas technique in 368 experiments. Architectural and environmental variables were measured. For each experiment, infection risk was estimated for TB exposure using the Wells-Riley model of airborne infection. We found that opening windows and doors provided median ventilation of 28 air changes/hour (ACH), more than double that of mechanically ventilated negative-pressure rooms ventilated at the 12 ACH recommended for high-risk areas, and 18 times that with windows and doors closed (p < 0.001). Facilities built more than 50 years ago, characterised by large windows and high ceilings, had greater ventilation than modern naturally ventilated rooms (40 versus 17 ACH; p < 0.001). Even within the lowest quartile of wind speeds, natural ventilation exceeded mechanical (p < 0.001). The Wells-Riley airborne infection model predicted that in mechanically ventilated rooms 39% of susceptible individuals would become infected following 24 h of exposure to untreated TB patients of infectiousness characterised in a well-documented outbreak. This infection rate compared with 33% in modern and 11% in pre-1950 naturally ventilated facilities with windows and doors open. Opening windows and doors maximises natural ventilation so that the risk of airborne contagion is much lower than with costly, maintenance-requiring mechanical ventilation systems. Old-fashioned clinical areas with high ceilings and large windows provide greatest protection. Natural ventilation costs little and is maintenance free, and is particularly suited to limited-resource settings and tropical climates, where the burden of TB and institutional TB transmission is highest. In settings where respiratory isolation is difficult and climate permits, windows and doors should be opened to reduce the risk of airborne contagion.

Does Bilevel Positive Airway Pressure Improve Outcome of Acute Respiratory Failure after Open-heart Surgery?

PubMed Central

Elgebaly, Ahmed Said

2017-01-01

Background: Respiratory failure is of concern in the postoperative period after cardiac surgeries. Invasive ventilation (intermittent positive pressure ventilation [IPPV]) carries the risks and complications of intubation and mechanical ventilation (MV). Aims: Noninvasive positive pressure ventilation (NIPPV) is an alternative method and as effective as IPPV in treating insufficiency of respiration with less complications and minimal effects on respiratory and hemodynamic parameters next to open-heart surgery. Design: This is a prospective, randomized and controlled study. Materials and Methods: Forty-four patients scheduled for cardiac surgery were divided into two equal groups: Group I (IPPV) and Group II (NIPPV). Heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR), oxygen saturation (SpO2), arterial blood gas, weaning time, reintubation, tracheotomy rate, MV time, postoperative hospital stay, and ventilator-associated pneumonia during the period of hospital stay were recorded. Results: There was statistically significant difference in HR between groups with higher in Group I at 30 and 60 min and at 12 and 24 h. According to MAP, it started to increase significantly at hypoxemia, 15 min, 30 min, 4 h, 12 h, and at 24 h which was higher in Group I also. RR, PaO2, and PaCO2 showed significant higher in Group II at 15, 30, and 60 min and 4 h. According to pH, there was a significant difference between groups at 15, 30, and 60 min and at 4, 12, and 24 h postoperatively. SpO2 showed higher significant values in Group I at 15 and 30 min and at 12 h postoperatively. Duration of postoperative supportive ventilation was higher in Group I than that of Group II with statistically significant difference. Complications were statistically insignificant between Group I and Group II. Conclusion: Our study showed superiority of invasive over noninvasive mode of ventilator support. However, NIPPV (bilevel positive airway pressure) was proved to be a safe method. PMID:28994676

Small scale power generation from biomass-technical potential

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lepori, W.A.; Cardenas, M.M.; Carney, O.B.

1983-12-01

System and nursery pig performance data for the Winter of 1983 were collected for a 96-pig capacity modified-open-front (MOF) naturally ventilated and a 96-pig capacity mechanically ventilated swine nurseries. Both nurseries utilized active solar collectors to provide in-floor heating at the rear of each pen along with hovers. The mechanically ventilated nursery utilized solar preheated ventilation air. The naturally ventilated nursery had double glazed solar windows to passively heat the interior space. The relative humidity in the naturally ventilated (NV) nursery averaged 20 percentage points higher than the mechanically ventilated (MV) nursery with no significant differences in air temperature. Themore » MV nursery used 50% more energy than the NV nursery and the NV nursery required 1.9 kWh/pig marketed less than that needed for the MV nursery. Pig performance figure were not significantly different between the two buildings. The feed to gain ration were 2.0 + or - 0.35 and 1.96 + or 0.38 for the MV and NV nurseries respectively.« less

Early mobilization and recovery in mechanically ventilated patients in the ICU: a bi-national, multi-centre, prospective cohort study.

PubMed

Hodgson, Carol; Bellomo, Rinaldo; Berney, Susan; Bailey, Michael; Buhr, Heidi; Denehy, Linda; Harrold, Megan; Higgins, Alisa; Presneill, Jeff; Saxena, Manoj; Skinner, Elizabeth; Young, Paul; Webb, Steven

2015-02-26

The aim of this study was to investigate current mobilization practice, strength at ICU discharge and functional recovery at 6 months among mechanically ventilated ICU patients. This was a prospective, multi-centre, cohort study conducted in twelve ICUs in Australia and New Zealand. Patients were previously functionally independent and expected to be ventilated for >48 hours. We measured mobilization during invasive ventilation, sedation depth using the Richmond Agitation and Sedation Scale (RASS), co-interventions, duration of mechanical ventilation, ICU-acquired weakness (ICUAW) at ICU discharge, mortality at day 90, and 6-month functional recovery including return to work. We studied 192 patients (mean age 58.1 ± 15.8 years; mean Acute Physiology and Chronic Health Evaluation (APACHE) (IQR) II score, 18.0 (14 to 24)). Mortality at day 90 was 26.6% (51/192). Over 1,351 study days, we collected information during 1,288 planned early mobilization episodes in patients on mechanical ventilation for the first 14 days or until extubation (whichever occurred first). We recorded the highest level of early mobilization. Despite the presence of dedicated physical therapy staff, no mobilization occurred in 1,079 (84%) of these episodes. Where mobilization occurred, the maximum levels of mobilization were exercises in bed (N = 94, 7%), standing at the bed side (N = 11, 0.9%) or walking (N = 26, 2%). On day three, all patients who were mobilized were mechanically ventilated via an endotracheal tube (N = 10), whereas by day five 50% of the patients mobilized were mechanically ventilated via a tracheostomy tube (N = 18). Early mobilization of patients receiving mechanical ventilation was uncommon. More than 50% of patients discharged from the ICU had developed ICU-acquired weakness, which was associated with death between ICU discharge and day-90. ClinicalTrials.gov NCT01674608. Registered 14 August 2012.

Evaluation of Mechanical Ventilator Use with Liquid Oxygen Systems

DTIC Science & Technology

2017-02-22

patients using long-term liquid oxygen differ from those on traditional treatment with oxygen concentrators and/or compressed gas cylinders? A...AFRL-SA-WP-SR-2017-0006 Evaluation of Mechanical Ventilator Use with Liquid Oxygen Systems Thomas Blakeman, MSc, RRT; Dario...To) August 2014 – September 2016 4. TITLE AND SUBTITLE Evaluation of Mechanical Ventilator Use with Liquid Oxygen Systems 5a. CONTRACT NUMBER

Caring for critically ill oldest old patients: a clinical review.

PubMed

Vargas, Nicola; Tibullo, Loredana; Landi, Emanuela; Carifi, Giovanni; Pirone, Alfonso; Pippo, Antonio; Alviggi, Immacolata; Tizzano, Renato; Salsano, Elisa; Di Grezia, Francesco; Vargas, Maria

2017-10-01

Despite technological advances, the mortality rate for critically ill oldest old patients remains high. The intensive caring should be able to combine technology and a deep humanity considering that the patients are living the last part of their lives. In addition to the traditional goals of ICU of reducing morbidity and mortality, of maintaining organ functions and restoring health, caring for seriously oldest old patients should take into account their end-of-life preferences, the advance or proxy directives if available, the prognosis, the communication, their life expectancy and the impact of multimorbidity. The aim of this review was to focus on all these aspects with an emphasis on some intensive procedures such as mechanical ventilation, noninvasive mechanical ventilation, cardiopulmonary resuscitation, renal replacement therapy, hemodynamic support, evaluation of delirium and malnutrition in this heterogeneous frail ICU population.

Contributors to fatigue in patients receiving mechanical ventilatory support: A descriptive correlational study.

PubMed

Chlan, Linda L; Savik, Kay

2015-10-01

To describe levels of fatigue and explore clinical factors that might contribute to fatigue in critically ill patients receiving mechanical ventilation. Descriptive, correlational design. Sample was a sub-set of patients enrolled in a randomised clinical trial testing patient-directed music for anxiety self-management. Clinical factors included age, gender, length of ICU stay, length of ventilatory support, illness severity (APACHE III), and sedative exposure (sedation intensity and frequency). Descriptive statistics and mixed models were used to address the study objectives. Medical and surgical intensive care units in the Midwestern United States. Fatigue was measured daily via a 100-mm Visual Analogue Scale, up to 25 days. A sample of 80 patients (50% female) receiving ventilatory support for a median 7.9 days (range 1-46) with a mean age of 61.2 years (SD 14.8) provided daily fatigue ratings. ICU admission APACHE III was 61.5 (SD 19.8). Baseline mean fatigue ratings were 60.7 (SD 27.9), with fluctuations over time indicating a general trend upward. Mixed models analysis implicated illness severity (β(se(β))=.27(.12)) and sedation frequency (β(se(β))=1.2(.52)) as significant contributors to fatigue ratings. Illness severity and more frequent sedative administration were related to higher fatigue ratings in these mechanically ventilated patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

CONTRIBUTORS TO FATIGUE IN PATIENTS RECEIVING MECHANICAL VENTILATORY SUPPORT: A DESCRIPTIVE CORRELATIONAL STUDY

PubMed Central

Chlan, Linda L.; Savik, Kay

2015-01-01

Objectives To describe levels of fatigue and explore clinical factors that might contribute to fatigue in critically ill patients receiving mechanical ventilation. Research Methodology/Design Descriptive, correlational design. Sample was a sub-set of patients enrolled in a randomized clinical trial testing patient-directed music for anxiety self-management. Clinical factors included age, gender, length of ICU stay, length of ventilatory support, illness severity (APACHE III), and sedative exposure (sedation intensity and frequency). Descriptive statistics and mixed models were used to address the study objectives. Setting Medical and surgical intensive care units in the Midwestern U.S.A. Main Outcome Measures Fatigue was measured daily via a 100-mm Visual Analog Scale, up to 25 days. Results A sample of 80 patients (50% female) receiving ventilatory support for a median 7.9 days (range 1-46) with a mean age of 61.2 years (SD 14.8) provided daily fatigue ratings. ICU admission APACHE III was 61.5 (SD 19.8). Baseline mean fatigue ratings were 60.7 (SD 27.9), with fluctuations over time indicating a general trend upward. Mixed models analysis implicated illness severity (β(se(β)) = .27(.12)) and sedation frequency (β(se(β)) = 1.2(.52)) as significant contributors to fatigue ratings. Conclusion Illness severity and more frequent sedative administration were related to higher fatigue ratings in these mechanically ventilated patients. PMID:26005034

The Society for Translational Medicine: clinical practice guidelines for mechanical ventilation management for patients undergoing lobectomy.

PubMed

Gao, Shugeng; Zhang, Zhongheng; Brunelli, Alessandro; Chen, Chang; Chen, Chun; Chen, Gang; Chen, Haiquan; Chen, Jin-Shing; Cassivi, Stephen; Chai, Ying; Downs, John B; Fang, Wentao; Fu, Xiangning; Garutti, Martínez I; He, Jianxing; He, Jie; Hu, Jian; Huang, Yunchao; Jiang, Gening; Jiang, Hongjing; Jiang, Zhongmin; Li, Danqing; Li, Gaofeng; Li, Hui; Li, Qiang; Li, Xiaofei; Li, Yin; Li, Zhijun; Liu, Chia-Chuan; Liu, Deruo; Liu, Lunxu; Liu, Yongyi; Ma, Haitao; Mao, Weimin; Mao, Yousheng; Mou, Juwei; Ng, Calvin Sze Hang; Petersen, René H; Qiao, Guibin; Rocco, Gaetano; Ruffini, Erico; Tan, Lijie; Tan, Qunyou; Tong, Tang; Wang, Haidong; Wang, Qun; Wang, Ruwen; Wang, Shumin; Xie, Deyao; Xue, Qi; Xue, Tao; Xu, Lin; Xu, Shidong; Xu, Songtao; Yan, Tiansheng; Yu, Fenglei; Yu, Zhentao; Zhang, Chunfang; Zhang, Lanjun; Zhang, Tao; Zhang, Xun; Zhao, Xiaojing; Zhao, Xuewei; Zhi, Xiuyi; Zhou, Qinghua

2017-09-01

Patients undergoing lobectomy are at significantly increased risk of lung injury. One-lung ventilation is the most commonly used technique to maintain ventilation and oxygenation during the operation. It is a challenge to choose an appropriate mechanical ventilation strategy to minimize the lung injury and other adverse clinical outcomes. In order to understand the available evidence, a systematic review was conducted including the following topics: (I) protective ventilation (PV); (II) mode of mechanical ventilation [e.g., volume controlled (VCV) versus pressure controlled (PCV)]; (III) use of therapeutic hypercapnia; (IV) use of alveolar recruitment (open-lung) strategy; (V) pre-and post-operative application of positive end expiratory pressure (PEEP); (VI) Inspired Oxygen concentration; (VII) Non-intubated thoracoscopic lobectomy; and (VIII) adjuvant pharmacologic options. The recommendations of class II are non-intubated thoracoscopic lobectomy may be an alternative to conventional one-lung ventilation in selected patients. The recommendations of class IIa are: (I) Therapeutic hypercapnia to maintain a partial pressure of carbon dioxide at 50-70 mmHg is reasonable for patients undergoing pulmonary lobectomy with one-lung ventilation; (II) PV with a tidal volume of 6 mL/kg and PEEP of 5 cmH 2 O are reasonable methods, based on current evidence; (III) alveolar recruitment [open lung ventilation (OLV)] may be beneficial in patients undergoing lobectomy with one-lung ventilation; (IV) PCV is recommended over VCV for patients undergoing lung resection; (V) pre- and post-operative CPAP can improve short-term oxygenation in patients undergoing lobectomy with one-lung ventilation; (VI) controlled mechanical ventilation with I:E ratio of 1:1 is reasonable in patients undergoing one-lung ventilation; (VII) use of lowest inspired oxygen concentration to maintain satisfactory arterial oxygen saturation is reasonable based on physiologic principles; (VIII) Adjuvant drugs such as nebulized budesonide, intravenous sivelestat and ulinastatin are reasonable and can be used to attenuate inflammatory response.

The Society for Translational Medicine: clinical practice guidelines for mechanical ventilation management for patients undergoing lobectomy

PubMed Central

Zhang, Zhongheng; Brunelli, Alessandro; Chen, Chang; Chen, Chun; Chen, Gang; Chen, Haiquan; Chen, Jin-Shing; Cassivi, Stephen; Chai, Ying; Downs, John B.; Fang, Wentao; Fu, Xiangning; Garutti, Martínez I.; He, Jianxing; Hu, Jian; Huang, Yunchao; Jiang, Gening; Jiang, Hongjing; Jiang, Zhongmin; Li, Danqing; Li, Gaofeng; Li, Hui; Li, Qiang; Li, Xiaofei; Li, Yin; Li, Zhijun; Liu, Chia-Chuan; Liu, Deruo; Liu, Lunxu; Liu, Yongyi; Ma, Haitao; Mao, Weimin; Mao, Yousheng; Mou, Juwei; Ng, Calvin Sze Hang; Petersen, René H.; Qiao, Guibin; Rocco, Gaetano; Ruffini, Erico; Tan, Lijie; Tan, Qunyou; Tong, Tang; Wang, Haidong; Wang, Qun; Wang, Ruwen; Wang, Shumin; Xie, Deyao; Xue, Qi; Xue, Tao; Xu, Lin; Xu, Shidong; Xu, Songtao; Yan, Tiansheng; Yu, Fenglei; Yu, Zhentao; Zhang, Chunfang; Zhang, Lanjun; Zhang, Tao; Zhang, Xun; Zhao, Xiaojing; Zhao, Xuewei; Zhi, Xiuyi; Zhou, Qinghua

2017-01-01

Patients undergoing lobectomy are at significantly increased risk of lung injury. One-lung ventilation is the most commonly used technique to maintain ventilation and oxygenation during the operation. It is a challenge to choose an appropriate mechanical ventilation strategy to minimize the lung injury and other adverse clinical outcomes. In order to understand the available evidence, a systematic review was conducted including the following topics: (I) protective ventilation (PV); (II) mode of mechanical ventilation [e.g., volume controlled (VCV) versus pressure controlled (PCV)]; (III) use of therapeutic hypercapnia; (IV) use of alveolar recruitment (open-lung) strategy; (V) pre-and post-operative application of positive end expiratory pressure (PEEP); (VI) Inspired Oxygen concentration; (VII) Non-intubated thoracoscopic lobectomy; and (VIII) adjuvant pharmacologic options. The recommendations of class II are non-intubated thoracoscopic lobectomy may be an alternative to conventional one-lung ventilation in selected patients. The recommendations of class IIa are: (I) Therapeutic hypercapnia to maintain a partial pressure of carbon dioxide at 50–70 mmHg is reasonable for patients undergoing pulmonary lobectomy with one-lung ventilation; (II) PV with a tidal volume of 6 mL/kg and PEEP of 5 cmH2O are reasonable methods, based on current evidence; (III) alveolar recruitment [open lung ventilation (OLV)] may be beneficial in patients undergoing lobectomy with one-lung ventilation; (IV) PCV is recommended over VCV for patients undergoing lung resection; (V) pre- and post-operative CPAP can improve short-term oxygenation in patients undergoing lobectomy with one-lung ventilation; (VI) controlled mechanical ventilation with I:E ratio of 1:1 is reasonable in patients undergoing one-lung ventilation; (VII) use of lowest inspired oxygen concentration to maintain satisfactory arterial oxygen saturation is reasonable based on physiologic principles; (VIII) Adjuvant drugs such as nebulized budesonide, intravenous sivelestat and ulinastatin are reasonable and can be used to attenuate inflammatory response. PMID:29221302

Current practice in airway management: A descriptive evaluation.

PubMed

Kjonegaard, Rebecca; Fields, Willa; King, Major L

2010-03-01

Ventilator-associated pneumonia, a common complication of mechanical ventilation, could be reduced if health care workers implemented evidence-based practices that decrease the risk for this complication. To determine current practice and differences in practices between registered nurses and respiratory therapists in managing patients receiving mechanical ventilation. A descriptive comparative design was used. A convenience sample of 41 registered nurses and 25 respiratory therapists who manage critical care patients treated with mechanical ventilation at Sharp Grossmont Hospital, La Mesa, California, completed a survey on suctioning techniques and airway management practices. Descriptive and inferential statistics were used to analyze the data. Significant differences existed between nurses and respiratory therapists for hyperoxygenation before suctioning (P =.03). In the 2 groups, nurses used the ventilator for hyper-oxygenation more often, and respiratory therapists used a bag-valve device more often (P =.03). Respiratory therapists instilled saline (P <.001) and rinsed the closed system with saline after suctioning (P =.003) more often than nurses did. Nurses suctioned oral secretions (P <.001) and the nose of orally intubated patients (P =.01), brushed patients' teeth with a toothbrush (P<.001), and used oral swabs to clean the mouth (P <.001) more frequently than respiratory therapists did. Nurses and respiratory therapists differed significantly in the management of patients receiving mechanical ventilation. To reduce the risk of ventilator-associated pneumonia, both nurses and respiratory therapists must be consistent in using best practices when managing patients treated with mechanical ventilation.

Effect of heat and moisture exchangers on the prevention of ventilator-associated pneumonia in critically ill patients.

PubMed

Auxiliadora-Martins, M; Menegueti, M G; Nicolini, E A; Alkmim-Teixeira, G C; Bellissimo-Rodrigues, F; Martins-Filho, O A; Basile-Filho, A

2012-12-01

Ventilator-associated pneumonia (VAP) remains one of the major causes of infection in the intensive care unit (ICU) and is associated with the length of hospital stay, duration of mechanical ventilation, and use of broad-spectrum antibiotics. We compared the frequency of VAP 10 months prior to (pre-intervention group) and 13 months after (post-intervention group) initiation of the use of a heat and moisture exchanger (HME) filter. This is a study with prospective before-and-after design performed in the ICU in a tertiary university hospital. Three hundred and fourteen patients were admitted to the ICU under mechanical ventilation, 168 of whom were included in group HH (heated humidifier) and 146 in group HME. The frequency of VAP per 1000 ventilator-days was similar for both the HH and HME groups (18.7 vs 17.4, respectively; P = 0.97). Duration of mechanical ventilation (11 vs 12 days, respectively; P = 0.48) and length of ICU stay (11 vs 12 days, respectively; P = 0.39) did not differ between the HH and HME groups. The chance of developing VAP was higher in patients with a longer ICU stay and longer duration of mechanical ventilation. This finding was similar when adjusted for the use of HME. The use of HME in intensive care did not reduce the incidence of VAP, the duration of mechanical ventilation, or the length of stay in the ICU in the study population.

Effect of heat and moisture exchangers on the prevention of ventilator-associated pneumonia in critically ill patients

PubMed Central

Auxiliadora-Martins, M.; Menegueti, M.G.; Nicolini, E.A.; Alkmim-Teixeira, G.C.; Bellissimo-Rodrigues, F.; Martins-Filho, O.A.; Basile-Filho, A.

2012-01-01

Ventilator-associated pneumonia (VAP) remains one of the major causes of infection in the intensive care unit (ICU) and is associated with the length of hospital stay, duration of mechanical ventilation, and use of broad-spectrum antibiotics. We compared the frequency of VAP 10 months prior to (pre-intervention group) and 13 months after (post-intervention group) initiation of the use of a heat and moisture exchanger (HME) filter. This is a study with prospective before-and-after design performed in the ICU in a tertiary university hospital. Three hundred and fourteen patients were admitted to the ICU under mechanical ventilation, 168 of whom were included in group HH (heated humidifier) and 146 in group HME. The frequency of VAP per 1000 ventilator-days was similar for both the HH and HME groups (18.7 vs 17.4, respectively; P = 0.97). Duration of mechanical ventilation (11 vs 12 days, respectively; P = 0.48) and length of ICU stay (11 vs 12 days, respectively; P = 0.39) did not differ between the HH and HME groups. The chance of developing VAP was higher in patients with a longer ICU stay and longer duration of mechanical ventilation. This finding was similar when adjusted for the use of HME. The use of HME in intensive care did not reduce the incidence of VAP, the duration of mechanical ventilation, or the length of stay in the ICU in the study population. PMID:23044627

Amyotrophic Lateral Sclerosis Patients' Perspectives on Use of Mechanical Ventilation.

ERIC Educational Resources Information Center

Young, Jenny M.; And Others

1994-01-01

Interviewed 13 amyotrophic lateral sclerosis patients. All believed that they alone should make decision regarding use of mechanical ventilation. Factors they considered important were quality of life, severity of disability, availability of ventilation by means of nasal mask, possible admission to long-term care facility, ability to discontinue…

High tidal volume ventilation induces NOS2 and impairs cAMP- dependent air space fluid clearance.

PubMed

Frank, James A; Pittet, Jean-Francois; Lee, Hyon; Godzich, Micaela; Matthay, Michael A

2003-05-01

Tidal volume reduction during mechanical ventilation reduces mortality in patients with acute lung injury and the acute respiratory distress syndrome. To determine the mechanisms underlying the protective effect of low tidal volume ventilation, we studied the time course and reversibility of ventilator-induced changes in permeability and distal air space edema fluid clearance in a rat model of ventilator-induced lung injury. Anesthetized rats were ventilated with a high tidal volume (30 ml/kg) or with a high tidal volume followed by ventilation with a low tidal volume of 6 ml/kg. Endothelial and epithelial protein permeability were significantly increased after high tidal volume ventilation but returned to baseline levels when tidal volume was reduced. The basal distal air space fluid clearance (AFC) rate decreased by 43% (P < 0.05) after 1 h of high tidal volume but returned to the preventilation rate 2 h after tidal volume was reduced. Not all of the effects of high tidal volume ventilation were reversible. The cAMP-dependent AFC rate after 1 h of 30 ml/kg ventilation was significantly reduced and was not restored when tidal volume was reduced. High tidal volume ventilation also increased lung inducible nitric oxide synthase (NOS2) expression and air space total nitrite at 3 h. Inhibition of NOS2 activity preserved cAMP-dependent AFC. Because air space edema fluid inactivates surfactant and reduces ventilated lung volume, the reduction of cAMP-dependent AFC by reactive nitrogen species may be an important mechanism of clinical ventilator-associated lung injury.

Health and Wellbeing of Occupants in Highly Energy Efficient Buildings: A Field Study.

PubMed

Wallner, Peter; Tappler, Peter; Munoz, Ute; Damberger, Bernhard; Wanka, Anna; Kundi, Michael; Hutter, Hans-Peter

2017-03-19

Passive houses and other highly energy-efficient buildings need mechanical ventilation. However, ventilation systems in such houses are regarded with a certain degree of skepticism by parts of the public due to alleged negative health effects. Within a quasi-experimental field study, we investigated if occupants of two types of buildings (mechanical vs. natural ventilation) experience different health, wellbeing and housing satisfaction outcomes and if associations with indoor air quality exist. We investigated 123 modern homes (test group: with mechanical ventilation; control group: naturally ventilated) built in the years 2010 to 2012 in the same geographic area and price range. Interviews of occupants based on standardized questionnaires and measurements of indoor air quality parameters were conducted twice (three months after moving in and one year later). In total, 575 interviews were performed (respondents' mean age 37.9 ± 9 years in the test group, 37.7 ± 9 years in the control group). Occupants of the test group rated their overall health status and that of their children not significantly higher than occupants of the control group at both time points. Adult occupants of the test group reported dry eyes statistically significantly more frequently compared to the control group (19.4% vs. 12.5%). Inhabitants of energy-efficient, mechanically ventilated homes rated the quality of indoor air and climate significantly higher. Self-reported health improved more frequently in the mechanically ventilated new homes ( p = 0.005). Almost no other significant differences between housing types and measuring time points were observed concerning health and wellbeing or housing satisfaction. Associations between vegetative symptoms (dizziness, nausea, headaches) and formaldehyde concentrations as well as between CO₂ levels and perceived stale air were observed. However, both associations were independent of the type of ventilation. In summary, occupants of the mechanically ventilated homes rated their health status slightly higher and their health improved significantly more frequently than in occupants of the control group. As humidity in homes with mechanical ventilation was lower, it seems plausible that the inhabitants reported dry eyes more frequently.

The Fluid Mechanics of Natural Ventilation

NASA Astrophysics Data System (ADS)

Linden, P. F.

1999-01-01

Natural ventilation of buildings is the flow generated by temperature differences and by the wind. The governing feature of this flow is the exchange between an interior space and the external ambient. Although the wind may often appear to be the dominant driving mechanism, in many circumstances temperature variations play a controlling feature on the ventilation since the directional buoyancy force has a large influence on the flow patterns within the space and on the nature of the exchange with the outside. Two forms of ventilation are discussed: mixing ventilation, in which the interior is at an approximately uniform temperature, and displacement ventilation, where there is strong internal stratification. The dynamics of these buoyancy-driven flows are considered, and the effects of wind on them are examined. The aim behind this work is to give designers rules and intuition on how air moves within a building; the research reveals a fascinating branch of fluid mechanics.

"Fighting the system": Families caring for ventilator-dependent children and adults with complex health care needs at home

PubMed Central

2011-01-01

Background An increasing number of individuals with complex health care needs now receive life-long and life-prolonging ventilatory support at home. Family members often take on the role of primary caregivers. The aim of this study was to explore the experiences of families giving advanced care to family members dependent on home mechanical ventilation. Methods Using qualitative research methods, a Grounded Theory influenced approach was used to explore the families' experiences. A total of 15 family members with 11 ventilator-dependent individuals (three children and eight adults) were recruited for 10 in-depth interviews. Results The core category, "fighting the system," became the central theme as family members were asked to describe their experiences. In addition, we identified three subcategories, "lack of competence and continuity", "being indispensable" and "worth fighting for". This study revealed no major differences in the families' experiences that were dependent on whether the ventilator-dependent individual was a child or an adult. Conclusions These findings show that there is a large gap between family members' expectations and what the community health care services are able to provide, even when almost unlimited resources are available. A number of measures are needed to reduce the burden on these family members and to make hospital care at home possible. In the future, the gap between what the health care can potentially provide and what they can provide in real life will rapidly increase. New proposals to limit the extremely costly provision of home mechanical ventilation in Norway will trigger new ethical dilemmas that should be studied further. PMID:21726441

Optimizing Hemodynamic Support of Acute Spinal Cord Injury Based on Injury Mechanism

DTIC Science & Technology

2015-10-01

energy production. tPO2 represents the balance between oxygen delivery and oxygen consumption . The oxygen portion of the Oxylite probe emits short...extubated (Mechanical ventilation was provided with 100% oxygen ). Over the time course of the next 2 days, SCBF returned to baseline values...1 sheds light on the dynamic changes that occur with oxygenation , blood flow, and metabolic responses in the penumbra of the traumatic spinal cord

Volatile anesthetic rescue therapy in children with acute asthma: innovative but costly or just costly?.

PubMed

Char, Danton S; Ibsen, Laura M; Ramamoorthy, Chandra; Bratton, Susan L

2013-05-01

To describe volatile anesthesia (VA) use for pediatric asthma, including complications and outcomes. Retrospective cohort study. Children's hospitals contributing to the Pediatric Health Information System between 2004-2008. Children 2-18 years old with a primary diagnosis code for asthma supported with mechanical ventilation. Those treated with VA were compared to those not treated with VA or extracorporeal membrane oxygenation. Hospital VA use was grouped as none, <5%, 5-10% and >10% among intubated children. One thousand five hundred and fifty-eight patients received mechanical ventilation at 40 hospitals for asthma: 47 (3%) received VA treatment at 11 (28%) hospitals. Those receiving a VA were significantly less likely to receive inhaled b-agonists, ipratropium bromide, and heliox, but more likely to receive neuromuscular blocking agents than patients treated without VA. Length of mechanical ventilation, hospital stay (length of stay [LOS]) and charges were significantly greater for those treated with VA. Aspiration was more common but death and air leak did not differ. Patients at hospitals with VA use >10% were significantly less likely to receive inhaled b agonist, ipratropium bromide, methylxanthines, and heliox, but more likely to receive systemic b agonist, neuromuscular blocking agents compared to those treated at hospitals not using VA. LOS, duration of ventilation, and hospital charges were significantly greater for patients treated at centers with high VA use. Mortality does not differ between centers that use VA or not. Patients treated at centers with high VA use had significantly increased hospital charges and increased LOS.

The effect of low level laser therapy on ventilator-induced lung injury in mice (Conference Presentation)

NASA Astrophysics Data System (ADS)

Szabari, Margit V.; Miller, Alyssa J.; Hariri, Lida P.; Hamblin, Michael R.; Musch, Guido; Stroh, Helene; Suter, Melissa J.

2016-03-01

Although mechanical ventilation (MV) is necessary to support gas exchange in critically ill patients, it can contribute to the development of lung injury and multiple organ dysfunction. It is known that high tidal volume (Vt) MV can cause ventilator-induced lung injury (VILI) in healthy lungs and increase the mortality of patients with Acute Respiratory Distress Syndrome. Low level laser therapy (LLLT) has demonstrated to have anti-inflammatory effects. We investigated whether LLLT could alleviate inflammation from injurious MV in mice. Adult mice were assigned to 2 groups: VILI+LLLT group (3 h of injurious MV: Vt=25-30 ml/kg, respiratory rate (RR)=50/min, positive end-expiratory pressure (PEEP)=0 cmH20, followed by 3 h of protective MV: Vt=9 ml/kg, RR=140/min, PEEP=2 cmH20) and VILI+no LLLT group. LLLT was applied during the first 30 min of the MV (810 nm LED system, 5 J/cm2, 1 cm above the chest). Respiratory impedance was measured in vivo with forced oscillation technique and lung mechanics were calculated by fitting the constant phase model. At the end of the MV, bronchoalveolar lavage (BAL) was performed and inflammatory cells counted. Lungs were removed en-bloc and fixed for histological evaluation. We hypothesize that LLLT can reduce lung injury and inflammation from VILI. This therapy could be translated into clinical practice, where it can potentially improve outcomes in patients requiring mechanical ventilation in the operating room or in the intensive care units.

Field and Laboratory Testing of Approaches to Smart Whole-House Mechanical Ventilation Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Eric; Fenaughty, Karen; Parker, Danny

Whole-house mechanical ventilation is a critical component to a comprehensive strategy for good indoor air quality (IAQ). However, due to lack of integration with standard heating and cooling systems, and perceptions from a portion of the homebuilding industry about risks related to increased energy use, increased cost, and decreased comfort, voluntary and code-required adoption varies among regions. Smart ventilation controls (SVC) balance energy consumption, comfort, and IAQ by optimizing mechanical ventilation operation to reduce the heating and/or cooling loads, improve management of indoor moisture, and maintain IAQ equivalence according to ASHRAE 62.2.

Field and Laboratory Testing of Approaches to Smart Whole-House Mechanical Ventilation Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Eric; Fenaughty, Karen; Parker, Danny

Whole-house mechanical ventilation is a critical component to a comprehensive strategy for good indoor air quality (IAQ). However, due to lack of integration with standard heating and cooling systems, and perceptions from a portion of the homebuilding industry about risks related to increased energy use, increased cost, and decreased comfort, voluntary and code-required adoption varies amongst regions. Smart ventilation controls (SVC) balance energy consumption, comfort, and IAQ by optimizing mechanical ventilation operation to reduce the heating and/or cooling loads, improve management of indoor moisture, and maintain IAQ equivalence according to ASHRAE 62.2.

Reducing heat stress under thermal insulation in protective clothing: microclimate cooling by a 'physiological' method.

PubMed

Glitz, K J; Seibel, U; Rohde, U; Gorges, W; Witzki, A; Piekarski, C; Leyk, D

2015-01-01

Heat stress caused by protective clothing limits work time. Performance improvement of a microclimate cooling method that enhances evaporative and to a minor extent convective heat loss was tested. Ten male volunteers in protective overalls completed a work-rest schedule (130 min; treadmill: 3 × 30 min, 3 km/h, 5% incline) with or without an additional air-diffusing garment (climatic chamber: 25°C, 50% RH, 0.2 m/s wind). Heat loss was supported by ventilating the garment with dry air (600 l/min, ≪5% RH, 25°C). Ventilation leads (M ± SD, n = 10, ventilated vs. non-ventilated) to substantial strain reduction (max. HR: 123 ± 12 b/min vs. 149 ± 24 b/min) by thermal relief (max. core temperature: 37.8 ± 0.3°C vs. 38.4 ± 0.4°C, max. mean skin temperature: 34.7 ± 0.8°C vs. 37.1 ± 0.3°C) and offers essential extensions in performance and work time under thermal insulation. Heat stress caused by protective clothing limits work time. Performance can be improved by a microclimate cooling method that supports evaporative and to a minor extent convective heat loss. Sweat evaporation is the most effective thermoregulatory mechanism for heat dissipation and can be enhanced by insufflating dry air into clothing.

Protective versus Conventional Ventilation for Surgery: A Systematic Review and Individual Patient Data Meta-analysis.

PubMed

Serpa Neto, Ary; Hemmes, Sabrine N T; Barbas, Carmen S V; Beiderlinden, Martin; Biehl, Michelle; Binnekade, Jan M; Canet, Jaume; Fernandez-Bustamante, Ana; Futier, Emmanuel; Gajic, Ognjen; Hedenstierna, Göran; Hollmann, Markus W; Jaber, Samir; Kozian, Alf; Licker, Marc; Lin, Wen-Qian; Maslow, Andrew D; Memtsoudis, Stavros G; Reis Miranda, Dinis; Moine, Pierre; Ng, Thomas; Paparella, Domenico; Putensen, Christian; Ranieri, Marco; Scavonetto, Federica; Schilling, Thomas; Schmid, Werner; Selmo, Gabriele; Severgnini, Paolo; Sprung, Juraj; Sundar, Sugantha; Talmor, Daniel; Treschan, Tanja; Unzueta, Carmen; Weingarten, Toby N; Wolthuis, Esther K; Wrigge, Hermann; Gama de Abreu, Marcelo; Pelosi, Paolo; Schultz, Marcus J

2015-07-01

Recent studies show that intraoperative mechanical ventilation using low tidal volumes (VT) can prevent postoperative pulmonary complications (PPCs). The aim of this individual patient data meta-analysis is to evaluate the individual associations between VT size and positive end-expiratory pressure (PEEP) level and occurrence of PPC. Randomized controlled trials comparing protective ventilation (low VT with or without high levels of PEEP) and conventional ventilation (high VT with low PEEP) in patients undergoing general surgery. The primary outcome was development of PPC. Predefined prognostic factors were tested using multivariate logistic regression. Fifteen randomized controlled trials were included (2,127 patients). There were 97 cases of PPC in 1,118 patients (8.7%) assigned to protective ventilation and 148 cases in 1,009 patients (14.7%) assigned to conventional ventilation (adjusted relative risk, 0.64; 95% CI, 0.46 to 0.88; P < 0.01). There were 85 cases of PPC in 957 patients (8.9%) assigned to ventilation with low VT and high PEEP levels and 63 cases in 525 patients (12%) assigned to ventilation with low VT and low PEEP levels (adjusted relative risk, 0.93; 95% CI, 0.64 to 1.37; P = 0.72). A dose-response relationship was found between the appearance of PPC and VT size (R2 = 0.39) but not between the appearance of PPC and PEEP level (R2 = 0.08). These data support the beneficial effects of ventilation with use of low VT in patients undergoing surgery. Further trials are necessary to define the role of intraoperative higher PEEP to prevent PPC during nonopen abdominal surgery.

Ventilator use, respiratory problems, and caregiver well-being in korean patients with amyotrophic lateral sclerosis receiving home-based care.

PubMed

Kim, Chul-Hoon; Kim, Myoung Soo

2014-10-01

The purpose of this study was to describe the status of ventilator use, respiratory problems, and caregiver well-being relating to patients with amyotrophic lateral sclerosis (ALS) using a home-based ventilator as well as to examine the relationship among ventilator use, respiratory problems, and caregiver well-being. Patients with ALS (n = 141) registered in the Severe-Rare Disease Center of the Korean Center for Disease Control and their caregivers (n = 83) were surveyed from August 2008 to April 2009. Trained research assistants visited patient homes; collected data using questionnaires; and then performed analyses with descriptive statistics, χ test, and t test as well as partial correlation analysis using SPSS WIN 18.0. Thirty-two patients used noninvasive ventilation (NIV), and 109 used tracheostomy and mechanical ventilation (TMV). One hundred of the TMV patients used the ventilator 24 hours per day. The ventilator circuit exchange cycle was 0.96 times per month for NIV patients and 1.17 times per month for TMV patients (t = -4.91, p < .001). However, NIV patients had a higher level of tidal volume than TMV patients (t = 3.34, p = .001). Approximately 22% of NIV patients and 24% of TMV patients used one or more physiotherapies for airway clearance. There was a significant relationship between hypoventilation symptoms and caregiver burden (r = .31, p = .006). Hypoventilation symptoms were positively related to physiotherapy (r = .24, p = .042), and physiotherapy was positively related to caregiver burden (r = .24, p = .043). On the basis of the findings of this study, care management for patients with ALS with a home-based ventilator as well as their caregiver's well-being was relatively inappropriate. We recommend that community-based support programs and burden relief programs be considered as managerial interventions.

[A young child with respiratory acidosis and hypoxia from mechanical ventilation with equipment made for adults].

PubMed

Joor, Fleur; Markhorst, Dick G; Kneyber, Martin C J; van Heerde, Marc

2011-01-01

During mechanical ventilation of young children, problems may arise due to the additional dead space of the ventilation circuit. This may lead to respiratory acidosis and even hypoxia in the child. A 3-month-old boy suffered from frequent apnoea. He was mechanically ventilated for this. Shortly after its initiation, he developed severe respiratory acidosis, hypoxemia and circulatory insufficiency. This was due to a large additional dead space caused by the use of equipment components made for adults. After he was switched to a circuit suitable for himself, he recovered rapidly. As a rule of thumb, an additional dead space of 1.5-2 ml/kg body weight is acceptable in young children. Emergency wards for young children should have specific equipment to mechanically ventilate them, and have a protocol paying explicit attention to the dead space.

Stockpiling Ventilators for Influenza Pandemics

PubMed Central

Araz, Ozgur M.; Morton, David P.; Johnson, Gregory P.; Damien, Paul; Clements, Bruce; Meyers, Lauren Ancel

2017-01-01

In preparing for influenza pandemics, public health agencies stockpile critical medical resources. Determining appropriate quantities and locations for such resources can be challenging, given the considerable uncertainty in the timing and severity of future pandemics. We introduce a method for optimizing stockpiles of mechanical ventilators, which are critical for treating hospitalized influenza patients in respiratory failure. As a case study, we consider the US state of Texas during mild, moderate, and severe pandemics. Optimal allocations prioritize local over central storage, even though the latter can be deployed adaptively, on the basis of real-time needs. This prioritization stems from high geographic correlations and the slightly lower treatment success assumed for centrally stockpiled ventilators. We developed our model and analysis in collaboration with academic researchers and a state public health agency and incorporated it into a Web-based decision-support tool for pandemic preparedness and response. PMID:28518041

Reducing the Indication for Ventilatory Support in the Severely Burned Patient: Results of a New Protocol Approach at a Regional Burn Center.

PubMed

Gille, Jochen; Bauer, Nicole; Malcharek, Michael J; Dragu, Adrian; Sablotzki, Armin; Taha, Hischam; Czeslick, Elke

2016-01-01

Initial management of the severely injured routinely includes sedation and mechanical ventilatory support. However, nonjudiciously applied mechanical ventilatory support can itself lead to poorer patient outcomes. In an attempt to reduce this iatrogenic risk, a standardized, in-house, five-point protocol providing clinical guidance on the use and duration of ventilation was introduced and analyzed, and the impact on patient outcomes was assessed. In 2007, a protocol for early spontaneous breathing was introduced and established in clinical practice. This protocol included: 1) early extubation (≤6 hours after admission) in the absence of absolute ventilatory indication; 2) avoidance of "routine intubation" in spontaneously breathing patients; 3) early postoperative extubation, including patients requiring multiple surgical interventions; 4) intensive chest and respiratory physiotherapy with routine application of expectorants; and 5) early active mobilization. A retrospective clinical study compared patients (group A) over a 2-year period admitted under the new protocol with a historical patient group (group B). Patients in group A (n = 38) had fewer ventilator days over the time-course of treatment (3 [1; 5.8] vs 18.5 days [0.5; 20.5]; P = .0001) with a lower rate of tracheostomies (15.8 vs 54%; P = .0003). Patients on ventilation at admission in group A had shorter ventilation periods after admission (4.75 [4; 22.25] vs 378 hours [8.5; 681.5]; P = .0003), and 66.7% of these patients were extubated within 6 hours of admission (vs 9.1% in group B). No patients fulfilling the inclusion criteria required re- or emergency intubation. In the first 5 days of treatment, significantly lower Sequential Organ Failure Assessment scores were recorded in group A. There was also a trend for lower mortality rates (0 [0%] vs 6 [14%]), sepsis rates (24 [63.2%] vs 37 [88.1%]), and cumulative fluid balance on days 3 and 7 in group A. In contrast, group A demonstrated an elevated rate of pneumonia (15 [39.5%] vs 8 [19%]). These trends, however, lacked statistical significance. Our five-point protocol was safe and easily translated into clinical practice. In the authors experience, this protocol significantly reduced the ventilatory period in severely injured. Furthermore, this study suggests that many injured may be over-treated with routine ventilation, which carries accompanying risks.

Epithelial and endothelial damage induced by mechanical ventilation modes.

PubMed

Suki, Béla; Hubmayr, Rolf

2014-02-01

The adult respiratory distress syndrome (ARDS) is a common cause of respiratory failure with substantial impact on public health. Patients with ARDS generally require mechanical ventilation, which risks further lung damage. Recent improvements in ARDS outcomes have been attributed to reductions in deforming stress associated with lung protective mechanical ventilation modes and settings. The following review details the mechanics of the lung parenchyma at different spatial scales and the response of its resident cells to deforming stress in order to provide the biologic underpinnings of lung protective care. Although lung injury is typically viewed through the lens of altered barrier properties and mechanical ventilation-associated immune responses, in this review, we call attention to the importance of heterogeneity and the physical failure of the load bearing cell and tissue elements in the pathogenesis of ARDS. Specifically, we introduce a simple elastic network model to better understand the deformations of lung regions, intra-acinar alveoli and cells within a single alveolus, and consider the role of regional distension and interfacial stress-related injury for various ventilation modes. Heterogeneity of stiffness and intercellular and intracellular stress failure are fundamental components of ARDS and their development also depends on the ventilation mode.

Non-invasive mechanical ventilation with spinal anesthesia for cesarean delivery.

PubMed

Erdogan, G; Okyay, D Z; Yurtlu, S; Hanci, V; Ayoglu, H; Koksal, B; Turan, I O

2010-10-01

We present the successful use of perioperative non-invasive mechanical ventilation in a morbidly obese pregnant woman with bronchial asthma, severe preeclampsia and pulmonary edema undergoing an emergency cesarean delivery with spinal anesthesia. The combination of non-invasive mechanical ventilation with neuraxial anesthesia may be of value in selected parturients with acute or chronic respiratory insufficiency requiring surgery. Copyright © 2010 Elsevier Ltd. All rights reserved.

[Determination of resting energy expenditure in critically ill children experiencing mechanical ventilation].

PubMed

Dong, Hong-ba; Yang, Yan-wen; Wang, Ying; Hong, Li

2012-11-01

Energy metabolism of critically ill children has its own characteristics, especially for those undergoing mechanical ventilation. We tried to assess the energy expenditure status and evaluate the use of predictive equations in such children. Moreover, the characteristics of the energy metabolism among various situation were explored. Fifty critically ill children undergoing mechanical ventilation were selected in this study. Data produced during the 24 hours of mechanical ventilation were collected for computation of severity of illness. Resting energy expenditure (REE) was determined at 24 hours after mechanical ventilation (MREE). Predictive resting energy expenditure (PREE) was calculated for each subject using age-appropriate equations (Schofield-HTWT, White). The study was approved by the hospital medical ethics committee and obtained parental written informed consent. The pediatric risk of mortality score 3 (PRISM3) and pediatric critical illness score (PCIS) were (7 ± 3) and (82 ± 4), respectively. MREE, Schofield-HTWT equation PREE and White equation PREE were (404.80 ± 178.28), (462.82 ± 160.38) and (427.97 ± 152.30) kcal/d, respectively; 70% were hypometabolic and 10% were hypermetabolic. MREE and PREE which were calculated using Schofield-HTWT equation and White equation, both were higher than MREE (P = 0.029). Correlation analysis was performed between PRISM3 and PCIS with MREE. There were no statistically significant correlation (P > 0.05). The hypometabolic response is apparent in critically ill children with mechanical ventilation; Schofield-HTWT equation and White equation could not predict energy requirements within acceptable clinical accuracy. In critically ill children undergoing mechanical ventilation, the energy expenditure is not correlated with the severity of illness.

Outcomes for patients with Guillain-Barré syndrome requiring mechanical ventilation: a literature review.

PubMed

de Boisanger, L

2016-02-01

This is a literature review of outcomes for patients with Guillain-Barré Syndrome (GBS) who require admission to the intensive care unit for mechanical ventilation. Respiratory distress is the leading cause of death in the acute phase, and occurs in about 25 % of patients. The aim of this review is to compile, analyse, and summarise the most relevant literature looking at outcomes for Guillain-Barré (GB) patients requiring admission to the intensive care unit and mechanical ventilation. A PubMed and Google-Scholar literature search was performed using the key words 'Guillain-Barré, Outcomes, Mechanical Ventilation, Prognosis, Mortality, ICU. All 7 papers from the years 2000-2014 which assessed outcomes for GBS patients requiring mechanical ventilation were included, and critically analysed. The parameters recorded by these studies looked at mortality, disability, length of hospitalisation, and complications. The mortality of GB patients requiring mechanical ventilation varied from 8.3 to 20 %, Disability was primarily measured by the GBS disability scale. One study deemed that a score of 0-1 was a positive outcome, and found that slightly over half 53.8 % of the patients fulfilled that criteria. Over half of the mechanically ventilated patients were required to be admitted for over 3 weeks. Complications during ICU admission are common, with bed-sores (40 %), pneumonia (30.2 %) and sepsis (17.4) being the most frequently encountered in one study. Accurate data are limited by the fact that these studies are retrospective, often covering long periods in the past. Larger, more recent, prospective, multi-centre studies will be required.

Partial Support Ventilation and Mitochondrial-Targeted Antioxidants Protect against Ventilator-Induced Decreases in Diaphragm Muscle Protein Synthesis.

PubMed

Hudson, Matthew B; Smuder, Ashley J; Nelson, W Bradley; Wiggs, Michael P; Shimkus, Kevin L; Fluckey, James D; Szeto, Hazel H; Powers, Scott K

2015-01-01

Mechanical ventilation (MV) is a life-saving intervention in patients in respiratory failure. Unfortunately, prolonged MV results in the rapid development of diaphragm atrophy and weakness. MV-induced diaphragmatic weakness is significant because inspiratory muscle dysfunction is a risk factor for problematic weaning from MV. Therefore, developing a clinical intervention to prevent MV-induced diaphragm atrophy is important. In this regard, MV-induced diaphragmatic atrophy occurs due to both increased proteolysis and decreased protein synthesis. While efforts to impede MV-induced increased proteolysis in the diaphragm are well-documented, only one study has investigated methods of preserving diaphragmatic protein synthesis during prolonged MV. Therefore, we evaluated the efficacy of two therapeutic interventions that, conceptually, have the potential to sustain protein synthesis in the rat diaphragm during prolonged MV. Specifically, these experiments were designed to: 1) determine if partial-support MV will protect against the decrease in diaphragmatic protein synthesis that occurs during prolonged full-support MV; and 2) establish if treatment with a mitochondrial-targeted antioxidant will maintain diaphragm protein synthesis during full-support MV. Compared to spontaneously breathing animals, full support MV resulted in a significant decline in diaphragmatic protein synthesis during 12 hours of MV. In contrast, diaphragm protein synthesis rates were maintained during partial support MV at levels comparable to spontaneous breathing animals. Further, treatment of animals with a mitochondrial-targeted antioxidant prevented oxidative stress during full support MV and maintained diaphragm protein synthesis at the level of spontaneous breathing animals. We conclude that treatment with mitochondrial-targeted antioxidants or the use of partial-support MV are potential strategies to preserve diaphragm protein synthesis during prolonged MV.

Role of non-invasive ventilation in difficult-to-wean children with acute neuromuscular disease.

PubMed

Reddy, V G; Nair, M P; Bataclan, F

2004-05-01

Weaning from mechanical ventilation in children could be time-consuming and on many occasions, leads to reintubation with its associate complications. We report two children with acute neuromuscular disease, in whom bi-level positive airway pressure (BiPAP) as a mode of non-invasive ventilation was successfully used to wean the child from ventilators and prevented the need for tracheostomy. Despite the limited number of studies published in the literature suggesting BiPAP as a mode of weaning from mechanical ventilation, the technique when applied correctly seems to be safe and effective in weaning and avoiding tracheostomy.

Predictors for mechanical ventilation and short-term prognosis in patients with Guillain-Barré syndrome.

PubMed

Wu, Xiujuan; Li, Chunrong; Zhang, Bing; Shen, Donghui; Li, Ting; Liu, Kangding; Zhang, Hong-Liang

2015-09-02

Guillain-Barré syndrome (GBS) is an immune-mediated disorder of the peripheral nervous system. Respiratory failure requiring mechanical ventilation (MV) is a serious complication of GBS. Identification of modifiable risk factors for MV and poor short-term prognosis in mechanically ventilated patients with GBS may contribute to the individualized management and may help improve the outcome of the patients. We retrospectively analyzed the clinical data of 541 patients who were diagnosed with GBS from 2003 to 2014. Independent predictors for MV and short-term prognosis in mechanically ventilated patients were identified via multivariate logistic regression analysis. The mean age was 41.6 years with a male predilection (61.2%). Eighty patients (14.8%) required MV. Multivariate analysis revealed that shorter interval from onset to admission (p < 0.05), facial nerve palsy (p < 0.01), glossopharyngeal and vagal nerve deficits (p < 0.01) and lower Medical Research Council (MRC) sum score at nadir (p < 0.01) were risk factors for MV; disease occurrence in summer (p < 0.01) was a protective factor. As to prognostic factors, absence of antecedent infections (p < 0.01) and lower MRC sum score at nadir (p < 0.01) were predictors of poor short-term prognosis in mechanically ventilated patients regardless of treatment modality. We further investigated the predictors of poor short-term prognosis in patients requiring MV with different nadir MRC sum scores. Combined use of intravenous corticosteroids with intravenous immunoglobulin (odds ratio 10.200, 95% confidence interval 1.068-97.407, p < 0.05) was an independent predictor of poor short-term prognosis in mechanically ventilated patients with a nadir MRC sum score from 0 to 12 points, regardless of existence of antecedent infection. Clinical predictors of MV and poor short-term prognosis in mechanically ventilated GBS patients were distinct. Add-on use of intravenous corticosteroids was a risk factor for poor short-term prognosis in mechanically ventilated patients with a nadir MRC sum score from 0 to 12 points.

[Unexpected treatable dyspnea caused by intratracheal granuloma in an amyotrophic lateral sclerosis patient with mechanical ventilation].

PubMed

Ishida, Shimon; Kimura, Fumiharu; Hosokawa, Takafumi; Satoh, Toshihiko; Furutama, Daisuke; Sugino, Masakazu

2007-09-01

Respiratory insufficiency is a problem that develops in nearly all people diagnosed with amyotrophic lateral sclerosis (ALS). A 46-year-old man with ALS, who had been in a bedridden state with tracheal ventilation support, complained of faintness and dyspnea. The airway pressure of the ventilator had increased, and bleeding from the trachea had occurred several times. A fiberoptic bronchoscopy showed granulation located on the anterior wall of the trachea and severe airway obstruction of the tracheostomy tube. Although a long tracheostomy tube had been intubated for the initial management of the tracheal granulation, a tumor on the posterior tracheal wall had relapsed and occluded the tracheal lumen. A self-expandable metallic airway stent was placed into the tracheal stenosis. After stenting, his symptoms of dyspnea and syncope imploved, and the increased airway pressure of the ventilator was normalized. We speculated that the tracheal granuloma had occurred due to a tracheal mucosal injury related to endotracheal suctioning. We should pay attention to complaints of dyspnea in ALS patients with tracheostomy and make a careful consideration to airway care including suction management.

Gastro-oesophageal reflux disease increases the risk of intensive care unit admittance and mechanical ventilation use among patients with chronic obstructive pulmonary disease: a nationwide population-based cohort study.

PubMed

Tsai, Chen-Liang; Lin, Yu-Huei; Wang, Meng-Ting; Chien, Li-Nien; Jeng, Chii; Chian, Chih-Feng; Perng, Wann-Cherng; Chiang, Chi-Huei; Chiou, Hung-Yi

2015-03-24

Gastro-oesophageal reflux disease (GORD) is common among chronic obstructive pulmonary disease (COPD) patients and may have a deleterious effect on COPD prognosis. However, few studies have investigated whether GORD increases the risk of severe outcomes such as intensive care unit (ICU) admittance or mechanical ventilator use among COPD patients. Propensity score matching by age, sex, comorbidities and COPD severity was used to match the 1,210 COPD patients with GORD sourced in this study to 2,420 COPD patients without GORD. The Kaplan-Meier method was used to explore the incidence of ICU admittance and machine ventilation with the log rank test being used to test for differences. Cox regression analysis was used to explore the risk of ICU admittance and mechanical ventilation use for patients with and without GORD. During the 12-month follow-up, GORD patients and non-GORD patients had 5.22 and 3.01 ICU admittances per 1000 person-months, and 4.34 and 2.41 mechanical ventilation uses per 1000 person-month, respectively. The log rank test revealed a difference in the incidence of ICU admittance and machine ventilation between the two cohorts. GORD was found to be an independent predicator of ICU admittance (adjusted hazard ratio (HRadj) 1.75, 95% confidence interval (CI) 1.28-2.38) and mechanical ventilation (HRadj 1.92, 95% CI 1.35-2.72). This is the first investigation to detect a significantly higher incidence rate and independently increased risk of admission to an ICU and mechanical ventilation use among COPD patients who subsequently developed GORD during the first year following their GORD diagnosis than COPD patients who did not develop GORD.

Effect of Heliox on Respiratory Outcomes during Rigid Bronchoscopy in Term Lambs.

PubMed

Sowder, Justin C; Dahl, Mar Janna; Zuspan, Kaitlin R; Albertine, Kurt H; Null, Donald M; Barneck, Mitchell D; Grimmer, J Fredrik

2018-03-01

Objective To (1) compare physiologic changes during rigid bronchoscopy during spontaneous and mechanical ventilation and (2) evaluate the efficacy of a helium-oxygen (heliox) gas mixture as compared with room air during rigid bronchoscopy. Study Design Crossover animal study evaluating physiologic parameters during rigid bronchoscopy. Outcomes were compared with predicted computational fluid analysis. Setting Simulated ventilation via computational fluid dynamics analysis and term lambs undergoing rigid bronchoscopy. Methods Respiratory and physiologic outcomes were analyzed in a lamb model simulating bronchoscopy during foreign body aspiration to compare heliox with room air. The main outcome measures were blood oxygen saturation, heart rate, blood pressure, partial pressure of oxygen, and partial pressure of carbon dioxide. Computational fluid dynamics analysis was performed with SOLIDWORKS within a rigid pediatric bronchoscope during simulated ventilation comparing heliox with room air. Results For room air, lambs desaturated within 3 minutes during mechanical ventilation versus normal oxygen saturation during spontaneous ventilation ( P = .01). No improvement in respiratory outcomes was seen between heliox and room air during mechanical ventilation. Computational fluid dynamics analysis demonstrates increased turbulence within size 3.5 bronchoscopes when comparing heliox and room air. Meaningful comparisons could not be made due to the intolerance of the lambs to heliox in vivo. Conclusion During mechanical ventilation on room air, lambs desaturate more quickly during rigid bronchoscopy on settings that should be adequate. Heliox does not improve ventilation during rigid bronchoscopy.

Efficacy of continuous versus intermittent subglottic secretion drainage in preventing ventilator-associated pneumonia in patients requiring mechanical ventilation: A single-center randomized controlled trial.

PubMed

Fujimoto, Hiroko; Yamaguchi, Osamu; Hayami, Hajime; Shimosaka, Mika; Tsuboi, Sayaka; Sato, Mitsunori; Takebayashi, Shigeo; Morita, Satoshi; Saito, Mari; Goto, Takahisa; Kurahashi, Kiyoyasu

2018-03-23

Aspiration of subglottic secretion is a widely used intervention to prevent ventilator-associated pneumonia (VAP). This study aimed to compare the efficacy of continuous and intermittent subglottic secretion drainage (SSD) in preventing VAP. A single-center randomized controlled trial was conducted on adult postoperative patients who were expected to undergo mechanical ventilation for more than 48 hours. Primary outcome measure was incidence of VAP and secondary outcome measures were length of mechanical ventilation and intensive-care unit (ICU) stay. Fifty-nine patients received continuous SSD, while 60 patients received intermittent SSD. Of these 119 patients, 88 (74%) were excluded and 15 and 16 patients were allocated to receive continuous and intermittent SSD, respectively. VAP was detected in 4 (26.7%) and 7 (43.8%) patients in the continuous and intermittent groups, respectively, (p=0.320). The length of mechanical ventilation was significantly shorter (p=0.034) in the continuous group (99.5±47.1 h) than in the intermittent group (159.9±94.5 h). The length of ICU stay was also shorter (p=0.0097) in the continuous group (6.3±2.1 days) than the intermittent group (9.8±4.8 days). Although continuous SSD did not reduce the incidence of VAP, it reduced the length of mechanical ventilation and ICU stay when compared to intermittent SSD.

Acute respiratory failure requiring mechanical ventilation in severe chronic obstructive pulmonary disease (COPD)

PubMed Central

Gadre, Shruti K.; Duggal, Abhijit; Mireles-Cabodevila, Eduardo; Krishnan, Sudhir; Wang, Xiao-Feng; Zell, Katrina; Guzman, Jorge

2018-01-01

Abstract There are limited data on the epidemiology of acute respiratory failure necessitating mechanical ventilation in patients with severe chronic obstructive pulmonary disease (COPD). The prognosis of acute respiratory failure requiring invasive mechanical ventilation is believed to be grim in this population. The purpose of this study was to illustrate the epidemiologic characteristics and outcomes of patients with underlying severe COPD requiring mechanical ventilation. A retrospective study of patients admitted to a quaternary referral medical intensive care unit (ICU) between January 2008 and December 2012 with a diagnosis of severe COPD and requiring invasive mechanical ventilation for acute respiratory failure. We evaluated 670 patients with an established diagnosis of severe COPD requiring mechanical ventilation for acute respiratory failure of whom 47% were male with a mean age of 63.7 ± 12.4 years and Acute physiology and chronic health evaluation (APACHE) III score of 76.3 ± 27.2. Only seventy-nine (12%) were admitted with a COPD exacerbation, 27(4%) had acute respiratory distress syndrome (ARDS), 78 (12%) had pneumonia, 78 (12%) had sepsis, and 312 (47%) had other causes of respiratory failure, including pulmonary embolism, pneumothorax, etc. Eighteen percent of the patients received a trial of noninvasive positive pressure ventilation. The median duration of mechanical ventilation was 3 days (interquartile range IQR 2–7); the median duration for ICU length of stay (LOS) was 5 (IQR 2–9) days and the median duration of hospital LOS was 12 (IQR 7–22) days. The overall ICU mortality was 25%. Patients with COPD exacerbation had a shorter median duration of mechanical ventilation (2 vs 4 days; P = .04), ICU (3 vs 5 days; P = .01), and hospital stay (10 vs 13 days; P = .01). The ICU mortality (9% vs 27%; P < .001), and the hospital mortality (17% vs 32%; P = .004) for mechanically ventilated patients with an acute exacerbation of severe COPD were lower than those with other etiologies of acute respiratory failure. A 1-unit increase in the APACHE III score was associated with a 1% decrease and having an active cancer was associated with a 45% decrease in ICU survival (P < .001). A discharge home at the time of index admission was associated an increased overall survival compared with any other discharge location (P < .001). We report good early outcomes, but significant long-term morbidity in patients with severe COPD requiring invasive mechanical ventilation for acute respiratory failure. A higher APACHE score and presence of active malignancy are associated with a decrease in ICU survival, whereas a discharge home is associated with an increase in the overall survival. PMID:29703009

Acute respiratory failure requiring mechanical ventilation in severe chronic obstructive pulmonary disease (COPD).

PubMed

Gadre, Shruti K; Duggal, Abhijit; Mireles-Cabodevila, Eduardo; Krishnan, Sudhir; Wang, Xiao-Feng; Zell, Katrina; Guzman, Jorge

2018-04-01

There are limited data on the epidemiology of acute respiratory failure necessitating mechanical ventilation in patients with severe chronic obstructive pulmonary disease (COPD). The prognosis of acute respiratory failure requiring invasive mechanical ventilation is believed to be grim in this population. The purpose of this study was to illustrate the epidemiologic characteristics and outcomes of patients with underlying severe COPD requiring mechanical ventilation.A retrospective study of patients admitted to a quaternary referral medical intensive care unit (ICU) between January 2008 and December 2012 with a diagnosis of severe COPD and requiring invasive mechanical ventilation for acute respiratory failure.We evaluated 670 patients with an established diagnosis of severe COPD requiring mechanical ventilation for acute respiratory failure of whom 47% were male with a mean age of 63.7 ± 12.4 years and Acute physiology and chronic health evaluation (APACHE) III score of 76.3 ± 27.2. Only seventy-nine (12%) were admitted with a COPD exacerbation, 27(4%) had acute respiratory distress syndrome (ARDS), 78 (12%) had pneumonia, 78 (12%) had sepsis, and 312 (47%) had other causes of respiratory failure, including pulmonary embolism, pneumothorax, etc. Eighteen percent of the patients received a trial of noninvasive positive pressure ventilation. The median duration of mechanical ventilation was 3 days (interquartile range IQR 2-7); the median duration for ICU length of stay (LOS) was 5 (IQR 2-9) days and the median duration of hospital LOS was 12 (IQR 7-22) days. The overall ICU mortality was 25%. Patients with COPD exacerbation had a shorter median duration of mechanical ventilation (2 vs 4 days; P = .04), ICU (3 vs 5 days; P = .01), and hospital stay (10 vs 13 days; P = .01). The ICU mortality (9% vs 27%; P < .001), and the hospital mortality (17% vs 32%; P = .004) for mechanically ventilated patients with an acute exacerbation of severe COPD were lower than those with other etiologies of acute respiratory failure. A 1-unit increase in the APACHE III score was associated with a 1% decrease and having an active cancer was associated with a 45% decrease in ICU survival (P < .001). A discharge home at the time of index admission was associated an increased overall survival compared with any other discharge location (P < .001).We report good early outcomes, but significant long-term morbidity in patients with severe COPD requiring invasive mechanical ventilation for acute respiratory failure. A higher APACHE score and presence of active malignancy are associated with a decrease in ICU survival, whereas a discharge home is associated with an increase in the overall survival.

Utilizing a Suited Manikin Test Apparatus and Spacesuit Ventilation Loop to Evaluate Carbon Dioxide Washout

NASA Technical Reports Server (NTRS)

Chullen, Cinda; Conger, Bruce; Korona, Adam; Kanne, Bryan; McMillin, Summer; Norcross, Jason; Jeng, Frank; Swickrath, Mike

2014-01-01

NASA is pursuing technology development of an Advanced Extravehicular Mobility Unit (AEMU) which is an integrated assembly made up of primarily a pressure garment system and a Portable Life Support System (PLSS). The PLSS is further composed of an oxygen subsystem, a ventilation subsystem, and a thermal subsystem. One of the key functions of the ventilation system is to remove and control the carbon dioxide delivered to the crewmember. Carbon dioxide washout is the mechanism by which CO2 levels are controlled within the spacesuit helmet to limit the concentration of CO2 inhaled by the crew member. CO2 washout performance is a critical parameter needed to ensure proper and robust designs that are insensitive to human variabilities in a spacesuit. A Suited Manikin Test Apparatus (SMTA) is being developed to augment testing of the PLSS ventilation loop in order to provide a lower cost and more controlled alternative to human testing. The CO2 removal function is performed by the regenerative Rapid Cycle Amine (RCA) within the PLSS ventilation loop and its performance is evaluated within the integrated SMTA and Ventilation Loop test system. This paper will provide a detailed description of the schematics, test configurations, and hardware components of this integrated system. Results and analysis of testing performed with this integrated system will be presented within this paper.

Utilizing a Suited Manikin Test Apparatus and Space Suit Ventilation Loop to Evaluate Carbon Dioxide Washout

NASA Technical Reports Server (NTRS)

Chullen, Cinda; Conger, Bruce; Korona, Adam; Kanne, Bryan; McMillin, Summer; Paul, Thomas; Norcross, Jason; Alonso, Jesus Delgado; Swickrath, Mike

2015-01-01

NASA is pursuing technology development of an Advanced Extravehicular Mobility Unit (AEMU) which is an integrated assembly made up of primarily a pressure garment system and a portable life support subsystem (PLSS). The PLSS is further composed of an oxygen subsystem, a ventilation subsystem, and a thermal subsystem. One of the key functions of the ventilation system is to remove and control the carbon dioxide (CO2) delivered to the crewmember. Carbon dioxide washout is the mechanism by which CO2 levels are controlled within the space suit helmet to limit the concentration of CO2 inhaled by the crew member. CO2 washout performance is a critical parameter needed to ensure proper and robust designs that are insensitive to human variabilities in a space suit. A suited manikin test apparatus (SMTA) was developed to augment testing of the PLSS ventilation loop in order to provide a lower cost and more controlled alternative to human testing. The CO2 removal function is performed by the regenerative Rapid Cycle Amine (RCA) within the PLSS ventilation loop and its performance is evaluated within the integrated SMTA and Ventilation Loop test system. This paper will provide a detailed description of the schematics, test configurations, and hardware components of this integrated system. Results and analysis of testing performed with this integrated system will be presented within this paper.

Hypercapnic encephalopathy syndrome: a new frontier for non-invasive ventilation?

PubMed

Scala, Raffaele

2011-08-01

According to the classical international guidelines, non-invasive ventilation is contraindicated in hypercapnic encephalopathy syndrome (HES) due to the poor compliance to ventilatory treatment of confused/agitated patients and the risk of aspirative pneumonia related to lack of airways protection. As a matter of fact, conventional mechanical ventilation has been recommended as "golden standard" in these patients. However, up to now there are not controlled data that have demonstrated in HES the advantage of conventional mechanical ventilation vs non-invasive ventilation. In fact, patients with altered mental status have been systematically excluded from the randomised and controlled trials performed with non-invasive ventilation in hypercapnic acute respiratory failure. Recent studies have clearly demonstrated that an initial cautious NPPV trial in selected HES patients may be attempt as long as there are no other contraindications and the technique is provided by experienced caregivers in a closely monitored setting where ETI is always readily available. The purpose of this review is to report the physiologic rationale, the clinical feasibility and the still open questions about the careful use of non-invasive ventilation in HES as first-line ventilatory strategy in place of conventional mechanical ventilation via endotracheal intubation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Avoiding endotracheal intubation of neonates undergoing laser surgery for retinopathy of prematurity.

PubMed

Woodhead, D D; Lambert, D K; Molloy, D A; Schmutz, N; Righter, E; Baer, V L; Christensen, R D

2007-04-01

Respiratory support of neonates during and following laser surgery for retinopathy of prematurity (ROP) is commonly accomplished using endotracheal intubation and mechanical ventilation. However, most patients undergoing ROP surgery have been weaned off mechanical ventilation days or weeks before the surgery. When they are electively re-intubated for ROP surgery, it can be difficult to extubate them postoperatively. One of the three level III neonatal intensive care units (NICUs) in the Intermountain Healthcare system initiated a program of using nasopharyngeal prongs, rather than endotracheal intubation, for respiratory support during ROP surgery. We performed an historic cohort analysis of all neonates undergoing ROP surgery during their NICU stay at the three level III NICU's between 1 January 2002 and 31 March 2006. Data collected included birth weight, gestational age at delivery and corrected gestational age at ROP surgery, whether or not they were intubated in the days immediately preceding the ROP surgery, whether or not they were electively intubated for the ROP surgery, the respiratory modality used during and the 3 days following ROP surgery, and all blood gas determinations and respiratory charges during this period. Fifty-four patients underwent ROP surgery during this period. All 23 from NICUs 'A' and 'B' had endotracheal intubation for surgery, while in NICU 'C' 24 were managed using nasopharyngeal prongs. The birth weights of those intubated for surgery (661+/-180 g, mean+/-s.d.) were similar to those not intubated (732+/-180 g). Similarly, the gestational age at birth did not differ between those intubated for surgery (25.2+/-1.3 week) and those not (25.6+/-2.1 week). The day following surgery, 77% (23/30) of those who had been intubated for surgery remained intubated and on mechanical ventilation, whereas only one (4%) of those not intubated for surgery was intubated in the postoperative period (P<0.001). On day 3 following surgery, 50% (15/30) of those intubated for surgery remained intubated and on mechanical ventilation, whereas none of those not intubated for surgery were intubated (P<0.001). Management with nasopharyngeal prongs did not result in higher PCO(2)s, or lower pH values, during or after surgery. Respiratory charges for the 3 days following surgery were 1762+/-678 dollars (mean+/-s.d.)/patient among those intubated versus 357+/-352 dollars/patient for those managed with nasopharyngeal prongs (P<0.001). Neonates undergoing laser surgery for ROP can often be supported intraoperatively and postoperatively using nasopharyngeal prongs, thus avoiding the need for endotracheal intubation.

Intraoperative ventilation strategy during cardiopulmonary bypass attenuates the release of matrix metalloproteinases and improves oxygenation.

PubMed

Beer, Lucian; Warszawska, Joanna Maria; Schenk, Peter; Debreceni, Tamás; Dworschak, Martin; Roth, Georg A; Szerafin, Tamás; Ankersmit, Hendrik Jan

2015-05-01

Patients undergoing open heart surgery with cardiopulmonary bypass (CPB) often develop a systemic immune reaction, characterized by an increase of proinflammatory and anti-inflammatory mediators. We previously demonstrated that continued mechanical ventilation during CPB reduces this response. We hypothesized that this strategy may also impact on matrix metalloproteinase (MMP) release. Thirty consecutive patients undergoing coronary artery bypass grafting with CPB were randomized into a ventilated (VG) (n = 15) and a standard non-ventilated group (NVG) (n = 15). Blood was collected at the beginning, at the end of surgery, and on the five consecutive days. MMPs, tissue inhibitor of matrix metalloproteinase 1 (TIMP-1), and lipocalin 2 (LCN2) were measured by enzyme-linked immunosorbent assay. Parameters of transpulmonary oxygen transport were assessed at different time points. MMP-8, MMP-9, and LCN2 were significantly lower at the end of surgery in VG compared with those in NVG patients (MMP-8 [ng/mL]: 7.1 [3.5] versus 12.5 [7.7], P = 0.02; MMP-9 [ng/mL]: 108 [42] versus 171 [98], P = 0.029; LCN2 [ng/mL]: 109 [42] versus 171 [98], P = 0.03). TIMP-1 concentrations were lower on postoperative day one, (TIMP-1 [ng/mL]: 174 [55] versus 273 [104], P = 0.003), whereas MMP-3 levels were lower on postoperative days four and five (MMP-3 [ng/mL]: 44 [17] versus 67 [35], P = 0.026). The arterial partial pressure of oxygen/fraction of inspired oxygen ratio was significantly higher in VG patients throughout the postoperative observation period, which did not affect the length of postoperative ventilatory support. Continued mechanical ventilation during CPB reduces serum levels of MMPs, their inhibitor TIMP-1 and LCN2, which preserves MMP-9 activity. The present study suggests that continued mechanical ventilation improves postoperative oxygenation and could potentially prevent aggravation of lung injury after CPB. Copyright © 2015 Elsevier Inc. All rights reserved.

Creation and Validation of an Automated Algorithm to Determine Postoperative Ventilator Requirements After Cardiac Surgery.

PubMed

Gabel, Eilon; Hofer, Ira S; Satou, Nancy; Grogan, Tristan; Shemin, Richard; Mahajan, Aman; Cannesson, Maxime

2017-05-01

In medical practice today, clinical data registries have become a powerful tool for measuring and driving quality improvement, especially among multicenter projects. Registries face the known problem of trying to create dependable and clear metrics from electronic medical records data, which are typically scattered and often based on unreliable data sources. The Society for Thoracic Surgery (STS) is one such example, and it supports manually collected data by trained clinical staff in an effort to obtain the highest-fidelity data possible. As a possible alternative, our team designed an algorithm to test the feasibility of producing computer-derived data for the case of postoperative mechanical ventilation hours. In this article, we study and compare the accuracy of algorithm-derived mechanical ventilation data with manual data extraction. We created a novel algorithm that is able to calculate mechanical ventilation duration for any postoperative patient using raw data from our EPIC electronic medical record. Utilizing nursing documentation of airway devices, documentation of lines, drains, and airways, and respiratory therapist ventilator settings, the algorithm produced results that were then validated against the STS registry. This enabled us to compare our algorithm results with data collected by human chart review. Any discrepancies were then resolved with manual calculation by a research team member. The STS registry contained a total of 439 University of California Los Angeles cardiac cases from April 1, 2013, to March 31, 2014. After excluding 201 patients for not remaining intubated, tracheostomy use, or for having 2 surgeries on the same day, 238 cases met inclusion criteria. Comparing the postoperative ventilation durations between the 2 data sources resulted in 158 (66%) ventilation durations agreeing within 1 hour, indicating a probable correct value for both sources. Among the discrepant cases, the algorithm yielded results that were exclusively correct in 75 (93.8%) cases, whereas the STS results were exclusively correct once (1.3%). The remaining 4 cases had inconclusive results after manual review because of a prolonged documentation gap between mechanical and spontaneous ventilation. In these cases, STS and algorithm results were different from one another but were both within the transition timespan. This yields an overall accuracy of 99.6% (95% confidence interval, 98.7%-100%) for the algorithm when compared with 68.5% (95% confidence interval, 62.6%-74.4%) for the STS data (P < .001). There is a significant appeal to having a computer algorithm capable of calculating metrics such as total ventilator times, especially because it is labor intensive and prone to human error. By incorporating 3 different sources into our algorithm and by using preprogrammed clinical judgment to overcome common errors with data entry, our results proved to be more comprehensive and more accurate, and they required a fraction of the computation time compared with manual review.

Humidification of inspired gases during mechanical ventilation.

PubMed

Gross, J L; Park, G R

2012-04-01

Humidification of inspired gas is mandatory for all mechanically ventilated patients to prevent secretion retention, tracheal tube blockage and adverse changes occurring to the respiratory tract epithelium. However, the debate over "ideal" humidification continues. Several devices are available that include active and passive heat and moisture exchangers and hot water humidifiers Each have their advantages and disadvantages in mechanically ventilated patients. This review explores each device in turn and defines their role in clinical practice.

Effect of prone positioning during mechanical ventilation on mortality among patients with acute respiratory distress syndrome: a systematic review and meta-analysis.

PubMed

Sud, Sachin; Friedrich, Jan O; Adhikari, Neill K J; Taccone, Paolo; Mancebo, Jordi; Polli, Federico; Latini, Roberto; Pesenti, Antonio; Curley, Martha A Q; Fernandez, Rafael; Chan, Ming-Cheng; Beuret, Pascal; Voggenreiter, Gregor; Sud, Maneesh; Tognoni, Gianni; Gattinoni, Luciano; Guérin, Claude

2014-07-08

Mechanical ventilation in the prone position is used to improve oxygenation and to mitigate the harmful effects of mechanical ventilation in patients with acute respiratory distress syndrome (ARDS). We sought to determine the effect of prone positioning on mortality among patients with ARDS receiving protective lung ventilation. We searched electronic databases and conference proceedings to identify relevant randomized controlled trials (RCTs) published through August 2013. We included RCTs that compared prone and supine positioning during mechanical ventilation in patients with ARDS. We assessed risk of bias and obtained data on all-cause mortality (determined at hospital discharge or, if unavailable, after longest follow-up period). We used random-effects models for the pooled analyses. We identified 11 RCTs (n=2341) that met our inclusion criteria. In the 6 trials (n=1016) that used a protective ventilation strategy with reduced tidal volumes, prone positioning significantly reduced mortality (risk ratio 0.74, 95% confidence interval 0.59-0.95; I2=29%) compared with supine positioning. The mortality benefit remained in several sensitivity analyses. The overall quality of evidence was high. The risk of bias was low in all of the trials except one, which was small. Statistical heterogeneity was low (I2<50%) for most of the clinical and physiologic outcomes. Our analysis of high-quality evidence showed that use of the prone position during mechanical ventilation improved survival among patients with ARDS who received protective lung ventilation. © 2014 Canadian Medical Association or its licensors.

Effect of prone positioning during mechanical ventilation on mortality among patients with acute respiratory distress syndrome: a systematic review and meta-analysis

PubMed Central

Sud, Sachin; Friedrich, Jan O.; Adhikari, Neill K. J.; Taccone, Paolo; Mancebo, Jordi; Polli, Federico; Latini, Roberto; Pesenti, Antonio; Curley, Martha A.Q.; Fernandez, Rafael; Chan, Ming-Cheng; Beuret, Pascal; Voggenreiter, Gregor; Sud, Maneesh; Tognoni, Gianni; Gattinoni, Luciano; Guérin, Claude

2014-01-01

Background: Mechanical ventilation in the prone position is used to improve oxygenation and to mitigate the harmful effects of mechanical ventilation in patients with acute respiratory distress syndrome (ARDS). We sought to determine the effect of prone positioning on mortality among patients with ARDS receiving protective lung ventilation. Methods: We searched electronic databases and conference proceedings to identify relevant randomized controlled trials (RCTs) published through August 2013. We included RCTs that compared prone and supine positioning during mechanical ventilation in patients with ARDS. We assessed risk of bias and obtained data on all-cause mortality (determined at hospital discharge or, if unavailable, after longest follow-up period). We used random-effects models for the pooled analyses. Results: We identified 11 RCTs (n = 2341) that met our inclusion criteria. In the 6 trials (n = 1016) that used a protective ventilation strategy with reduced tidal volumes, prone positioning significantly reduced mortality (risk ratio 0.74, 95% confidence interval 0.59–0.95; I2 = 29%) compared with supine positioning. The mortality benefit remained in several sensitivity analyses. The overall quality of evidence was high. The risk of bias was low in all of the trials except one, which was small. Statistical heterogeneity was low (I2 < 50%) for most of the clinical and physiologic outcomes. Interpretation: Our analysis of high-quality evidence showed that use of the prone position during mechanical ventilation improved survival among patients with ARDS who received protective lung ventilation. PMID:24863923

Atelectasis and mechanical ventilation mode during conservative oxygen therapy: A before-and-after study.

PubMed

Suzuki, Satoshi; Eastwood, Glenn M; Goodwin, Mark D; Noë, Geertje D; Smith, Paul E; Glassford, Neil; Schneider, Antoine G; Bellomo, Rinaldo

2015-12-01

The purpose of the study is to assess the effect of a conservative oxygen therapy (COT) (target SpO2 of 90%-92%) on radiological atelectasis and mechanical ventilation modes. We conducted a secondary analysis of 105 intensive care unit patients from a pilot before-and-after study. The primary outcomes of this study were changes in atelectasis score (AS) of 555 chest radiographs assessed by radiologists blinded to treatment allocation and time to weaning from mandatory ventilation and first spontaneous ventilation trial (SVT). There was a significant difference in overall AS between groups, and COT was associated with lower time-weighted average AS. In addition, in COT patients, change from mandatory to spontaneous ventilation or time to first SVT was shortened. After adjustment for baseline characteristics and interactions between oxygen therapy, radiological atelectasis, and mechanical ventilation management, patients in the COT group had significantly lower "best" AS (adjusted odds ratio, 0.28 [95% confidence interval {CI}, 0.12-0.66]; P=.003) and greater improvement in AS in the first 7 days (adjusted odds ratio, 0.42 [95% CI, 0.17-0.99]; P=.049). Moreover, COT was associated with significantly earlier successful weaning from a mandatory ventilation mode (adjusted hazard ratio, 2.96 [95% CI, 1.73-5.04]; P<.001) and with shorter time to first SVT (adjusted hazard ratio, 1.77 [95% CI, 1.13-2.78]; P=.013). In mechanically ventilated intensive care unit patients, COT might be associated with decreased radiological evidence of atelectasis, earlier weaning from mandatory ventilation modes, and earlier first trial of spontaneous ventilation. Copyright © 2015 Elsevier Inc. All rights reserved.

Extracorporeal respiratory support in adult patients.

PubMed

Romano, Thiago Gomes; Mendes, Pedro Vitale; Park, Marcelo; Costa, Eduardo Leite Vieira

2017-01-01

In patients with severe respiratory failure, either hypoxemic or hypercapnic, life support with mechanical ventilation alone can be insufficient to meet their needs, especially if one tries to avoid ventilator settings that can cause injury to the lungs. In those patients, extracorporeal membrane oxygenation (ECMO), which is also very effective in removing carbon dioxide from the blood, can provide life support, allowing the application of protective lung ventilation. In this review article, we aim to explore some of the most relevant aspects of using ECMO for respiratory support. We discuss the history of respiratory support using ECMO in adults, as well as the clinical evidence; costs; indications; installation of the equipment; ventilator settings; daily care of the patient and the system; common troubleshooting; weaning; and discontinuation. RESUMO Em pacientes com insuficiência respiratória grave (hipoxêmica ou hipercápnica), o suporte somente com ventilação mecânica pode ser insuficiente para suas necessidades, especialmente quando se tenta evitar o uso de parâmetros ventilatórios que possam causar danos aos pulmões. Nesses pacientes, extracorporeal membrane oxygenation (ECMO, oxigenação extracorpórea por membrana), que também é muito eficaz na remoção de dióxido de carbono do sangue, pode manter a vida, permitindo o uso de ventilação pulmonar protetora. No presente artigo de revisão, objetivamos explorar alguns dos aspectos mais relevantes do suporte respiratório por ECMO. Discutimos a história do suporte respiratório por ECMO em adultos; evidências clínicas; custos; indicações; instalação do equipamento; parâmetros ventilatórios; cuidado diário do paciente e do sistema; solução de problemas comuns; desmame e descontinuação.

Assessing Respiratory System Mechanical Function.

PubMed

Restrepo, Ruben D; Serrato, Diana M; Adasme, Rodrigo

2016-12-01

The main goals of assessing respiratory system mechanical function are to evaluate the lung function through a variety of methods and to detect early signs of abnormalities that could affect the patient's outcomes. In ventilated patients, it has become increasingly important to recognize whether respiratory function has improved or deteriorated, whether the ventilator settings match the patient's demand, and whether the selection of ventilator parameters follows a lung-protective strategy. Ventilator graphics, esophageal pressure, intra-abdominal pressure, and electric impedance tomography are some of the best-known monitoring tools to obtain measurements and adequately evaluate the respiratory system mechanical function. Copyright © 2016 Elsevier Inc. All rights reserved.

Low-tidal volume mechanical ventilation in patients with acute respiratory distress syndrome caused by pandemic influenza A/H1N1 infection.

PubMed

Oh, Dong Kyu; Lee, Myung Goo; Choi, Eun Young; Lim, Jaemin; Lee, Hyun-Kyung; Kim, Seok Chan; Lim, Chae-Man; Koh, Younsuck; Hong, Sang-Bum

2013-08-01

Low-tidal volume (TV) mechanical ventilation is an important manipulation in managing patients with acute respiratory distress syndrome (ARDS). However, there is no definite evidence to support the use of this intervention in patients with viral etiologies. A retrospective observational study of 104 patients with ARDS caused by pandemic influenza A/H1N1 infection admitted to 28 intensive care units (ICUs) in Korea was performed. Patients were categorized into 3 groups according to the TV they received: TV less than or equal to 7 mL/kg, TV greater than 7 mL/kg but less than or equal to 9 mL/kg, or TV greater than 9 mL/kg. The mean age was 55.1 years, and 55.8% were male (n = 58). Patients with TV greater than 9 mL/kg showed higher 28-day ICU mortality than the 2 other groups (vs TV < 7 mL/kg, P = .007 and vs 7 mL/kg < TV ≤ 9 mL/kg, P = .004, respectively). Patients with TV less than or equal to 7 mL/kg required ventilators, ICU admissions, and hospitalizations for fewer days than those with TV greater than 7 mL/kg (11.4 vs 6.1 days for 28-day ventilator-free days, 9.7 vs 4.9 days for 28-day ICU-free days, and 5.2 vs 2.4 days for 28-day hospital-free days, respectively). Tidal volume greater than 9 mL/kg (hazard rate, 2.459; P = .003) and Sequential Organ Failure Assessment score (hazard rate, 1.158; P = .014) were significant predictors of 28-day ICU mortality. Low-TV mechanical ventilation still benefits patients with ARDS caused by viral pneumonia. Copyright © 2013 Elsevier Inc. All rights reserved.

Efficacy of a bundle approach in preventing the incidence of ventilator associated pneumonia (VAP)

PubMed Central

Burja, Sandra; Belec, Tina; Bizjak, Nika; Mori, Jernej; Markota, Andrej; Sinkovič, Andreja

2018-01-01

Ventilator-associated pneumonia (VAP) is a potentially preventable iatrogenic illness that may develop following mechanical ventilation. A bundle for the prevention of VAP consists of different measures which may vary between institutions, and may include: elevation of the head of the bed, oral care with chlorhexidine, subglottic suctioning, daily assessment for extubation and the need for proton-pump inhibitors, use of closed suction systems, and maintaining endotracheal cuff pressure at 25 cmH2O. Our aim was to determine the efficacy of a VAP prevention bundle, consisting of the above-mentioned measures, by evaluating the incidence of VAP before (no-VAP-B group) and after (VAP-B group) the introduction of the bundle. We retrospectively evaluated the data for patients who were mechanically ventilated with an endotracheal tube, in the period between 1 September and 31 December 2014 (no-VAP-B group, n = 55, 54.5% males, mean age 67.8 ± 14.5 years) and between 1 January to 30 April 2015 (VAP-B group, n = 74, 62.1% males, mean age 64.8 ± 13.7 years). There were no statistically significant differences between no-VAP-B and VAP-B groups in demographic data, intensive care unit (ICU) mortality, hospital mortality, duration of ICU treatment, and duration of mechanical ventilation. No significant differences in the rates of VAP and early VAP (onset ≤7 days after intubation) were found between no-VAP-B and VAP-B groups (41.8% versus 25.7%, p = 0.06 and 10.9% versus 12.2%, p > 0.99, respectively). However, a significant decrease in the late VAP (onset >8 days after intubation) was found in VAP-B group compared to no-VAP-B group (13.5% versus 30.9%, p = 0.027). Overall, our results support the use of VAP prevention bundle in clinical practice. PMID:28976870

Death by acid rain: VAP or EXIT?

PubMed

Thorburn, Kentigern; Darbyshire, Andrew

2009-01-01

Ventilator-associated pneumonia (VAP) is a new (nosocomial) lower respiratory tract infection diagnosed in mechanically ventilated patients 48 or more hours after intubation. There is no gold standard for establishing the diagnosis and its pathogenesis is iatrogenic and multifactorial. Gastro-oesophageal reflux is common in mechanically ventilated children, but its role in VAP remains speculative. VAP is associated with increased mortality and morbidity, prolonged duration of ventilation and hospital stay, and escalated costs of hospitalisation. VAP 'bundles' are championed as the antidote.

Effect of early versus late or no tracheostomy on mortality and pneumonia of critically ill patients receiving mechanical ventilation: a systematic review and meta-analysis.

PubMed

Siempos, Ilias I; Ntaidou, Theodora K; Filippidis, Filippos T; Choi, Augustine M K

2015-02-01

Delay of tracheostomy for roughly 2 weeks after translaryngeal intubation of critically ill patients is the presently recommended practice and is supported by findings from large trials. However, these trials were suboptimally powered to detect small but clinically important effects on mortality. We aimed to assess the benefit of early versus late or no tracheostomy on mortality and pneumonia in critically ill patients who need mechanical ventilation. We systematically searched PubMed, CINAHL, Embase, Web of Science, DOAJ, the Cochrane Library, references of relevant articles, scientific conference proceedings, and grey literature up to Aug 31, 2013, to identify randomised controlled trials comparing early tracheostomy (done within 1 week after translaryngeal intubation) with late (done any time after the first week of mechanical ventilation) or no tracheostomy and reporting on mortality or incidence of pneumonia in critically ill patients under mechanical ventilation. Our primary outcomes were all-cause mortality during the stay in the intensive-care unit and incidence of ventilator-associated pneumonia. Mortality during the stay in the intensive-care unit was a composite endpoint of definite intensive-care-unit mortality, presumed intensive-care-unit mortality, and 28-day mortality. We calculated pooled odds ratios (OR), pooled risk ratios (RR), and 95% CIs with a random-effects model. All but complications analyses were done on an intention-to-treat basis. Analyses of 13 trials (2434 patients, 648 deaths) showed that all-cause mortality in the intensive-care unit was not significantly lower in patients assigned to the early versus the late or no tracheostomy group (OR 0·80, 95% CI 0·59-1·09; p=0·16). This result persisted when we considered only trials with a low risk of bias (511 deaths; OR 0·80, 95% CI 0·59-1·09; p=0·16; eight trials with 1934 patients). Incidence of ventilator-associated pneumonia was lower in mechanically ventilated patients assigned to the early versus the late or no tracheostomy group (691 cases; OR 0·60, 95% CI 0·41-0·90; p=0·01; 13 trials with 1599 patients). There was no evidence of a difference between the compared groups for 1-year mortality (788 deaths; RR 0·93, 95% CI 0·85-1·02; p=0·14; three trials with 1529 patients). The synthesised evidence suggests that early tracheostomy is not associated with lower mortality in the intensive-care unit than late or no tracheostomy. However, early, compared with late or no, tracheostomy might be associated with a lower incidence of pneumonia; a finding that could question the present practice of delaying tracheostomy beyond the first week after translaryngeal intubation in mechanically ventilated patients. Nevertheless, the scarcity of a beneficial effect on long-term mortality and the potential complications associated with tracheostomy need careful consideration; thus, further studies focusing on long-term outcomes are warranted. None. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Suspension of Respiratory Support in Patients with Amyotrophic Lateral Sclerosis].

PubMed

Silberberg, Agustín A; Robetto, Josefina; Achával, Mora

2018-01-01

Decision making in advanced Amyotrophic Lateral Sclerosis (ALS) patients keeps on being a controversial issue. The aim of this work is to discuss ethical implications of withdrawing respiratory support treatment in patients with ALS. Through a bibliographic search on Pubmed database (2010-2016) we investigated whether or not the use of Non-Invasive Ventilation (NIV) and Mechanical Ventilation (MV) would increase survival and quality of life. We included 38 review articles. From these papers, results and ethical implications of initiating and mainly withdrawing respiratory support were analyzed. Survival time increased with NIV and with MV. Quality of life, above all according to physiological criteria, improved with NIV but regarding MV it remained controversial. Implementation and future withdrawal of MV seemed open to medical and ethical discussion. From a perspective of the intrinsic dignity of every human being, whatever its quality of life was, and knowing that no effective therapies for the underlying disease are available, the decision to remove MV in a patient with advanced ALS requires: knowledge of the will of the patient and, above all, evaluating whether this respiratory support measure is becoming objectively disproportionate.

The influence of mechanical ventilation on physiological parameters in ball pythons (Python regius).

PubMed

Jakobsen, Sashia L; Williams, Catherine J A; Wang, Tobias; Bertelsen, Mads F

2017-05-01

Mechanical ventilation is widely recommended for reptiles during anesthesia, and while it is well-known that their low ectothermic metabolism requires much lower ventilation than in mammals, very little is known about the influence of ventilation protocol on the recovery from anesthesia. Here, 15 ball pythons (Python regius) were induced and maintained with isoflurane for 60min at one of three ventilation protocols (30, 125, or 250mlmin -1 kg -1 body mass) while an arterial catheter was inserted, and ventilation was then continued on 100% oxygen at the specified rate until voluntary extubation. Mean arterial blood pressure and heart rate (HR) were measured, and arterial blood samples collected at 60, 80, 180min and 12 and 24h after intubation. In all three groups, there was evidence of a metabolic acidosis, and snakes maintained at 30mlmin -1 kg -1 experienced an additional respiratory acidosis, while the two other ventilation protocols resulted in normal or low arterial PCO 2 . In general, normal acid-base status was restored within 12h in all three protocols. HR increased by 143±64% during anesthesia with high mechanical ventilation (250mlmin -1 kg -1 ) in comparison with recovered values. Recovery times after mechanical ventilation at 30, 125, or 250mlmin -1 kg -1 were 289±70, 126±16, and 68±7min, respectively. Mild overventilation may result in a faster recovery, and the associated lowering of arterial PCO 2 normalised arterial pH in the face of metabolic acidosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Rescue therapy by switching to total face mask after failure of face mask-delivered noninvasive ventilation in do-not-intubate patients in acute respiratory failure.

PubMed

Lemyze, Malcolm; Mallat, Jihad; Nigeon, Olivier; Barrailler, Stéphanie; Pepy, Florent; Gasan, Gaëlle; Vangrunderbeeck, Nicolas; Grosset, Philippe; Tronchon, Laurent; Thevenin, Didier

2013-02-01

To evaluate the impact of switching to total face mask in cases where face mask-delivered noninvasive mechanical ventilation has already failed in do-not-intubate patients in acute respiratory failure. Prospective observational study in an ICU and a respiratory stepdown unit over a 12-month study period. Switching to total face mask, which covers the entire face, when noninvasive mechanical ventilation using facial mask (oronasal mask) failed to reverse acute respiratory failure. Seventy-four patients with a do-not-intubate order and treated by noninvasive mechanical ventilation for acute respiratory failure. Failure of face mask-delivered noninvasive mechanical ventilation was associated with a three-fold increase in in-hospital mortality (36% vs. 10.5%; p = 0.009). Nevertheless, 23 out of 36 patients (64%) in whom face mask-delivered noninvasive mechanical ventilation failed to reverse acute respiratory failure and, therefore, switched to total face mask survived hospital discharge. Reasons for switching from facial mask to total face mask included refractory hypercapnic acute respiratory failure (n = 24, 66.7%), painful skin breakdown or facial mask intolerance (n = 11, 30%), and refractory hypoxemia (n = 1, 2.7%). In the 24 patients switched from facial mask to total face mask because of refractory hypercapnia, encephalopathy score (3 [3-4] vs. 2 [2-3]; p < 0.0001), PaCO2 (87 ± 25 mm Hg vs. 70 ± 17 mm Hg; p < 0.0001), and pH (7.24 ± 0.1 vs. 7.32 ± 0.09; p < 0.0001) significantly improved after 2 hrs of total face mask-delivered noninvasive ventilation. Patients switched early to total face mask (in the first 12 hrs) developed less pressure sores (n = 5, 24% vs. n = 13, 87%; p = 0.0002), despite greater length of noninvasive mechanical ventilation within the first 48 hrs (44 hrs vs. 34 hrs; p = 0.05) and less protective dressings (n = 2, 9.5% vs. n = 8, 53.3%; p = 0.007). The optimal cutoff value for face mask-delivered noninvasive mechanical ventilation duration in predicting facial pressure sores was 11 hrs (area under the receiver operating characteristic curve, 0.86 ± 0.04; 95% confidence interval 0.76-0.93; p < 0.0001; sensitivity, 84%; specificity, 71%). In patients in hypercapnic acute respiratory failure, for whom escalation to intubation is deemed inappropriate, switching to total face mask can be proposed as a last resort therapy when face mask-delivered noninvasive mechanical ventilation has already failed to reverse acute respiratory failure. This strategy is particularly adapted to provide prolonged periods of continuous noninvasive mechanical ventilation while preventing facial pressure sores.

Intravenous immunoglobulins in severe Guillian-Barre syndrome in childhood.

PubMed

Shanbag, Preeti; Amirtharaj, Cynthia; Pathak, Ashish

2003-07-01

This is a retrospective analysis of 25 children with severe Guillain-Barre syndrome admitted to our PICU. All children were treated with intravenous immunoglobulins (IVIG) in a dose of 2 g/kg body weight over 2-5 days in addition to supportive and respiratory care. Seventeen children were elective admissions to the PICU whereas 8 children were transferred from other hospitals in a critical condition. Five of 8 of the late referrals died as compared to none of the elective admissions. All 8 of the late referrals required mechanical ventilation as against 3 of the 17 elective admissions. Mean duration of PICU stay in the late referrals was 27 days as compared to 15 days in the elective admissions. The authors concur with previously published reports, that early use of IVIG could reduce the mortality and the need for intubation and mechanical ventilation.

An evaluation of instruments for scoring physiological and behavioral cues of pain, non-pain related distress, and adequacy of analgesia and sedation in pediatric mechanically ventilated patients: A systematic review.

PubMed

Dorfman, Tamara L; Sumamo Schellenberg, Elizabeth; Rempel, Gwen R; Scott, Shannon D; Hartling, Lisa

2014-04-01

Advancing technology allows for successful treatment of children with life-threatening illnesses. Effectively assessing and optimally treating a child's distress during their stay in the Pediatric Intensive Care Unit (PICU) is paramount. Objective measures of distress in mechanically ventilated pediatric patients are increasingly available but few have been evaluated. The objectives of this systematic review were to identify available instruments appropriate for measuring physiological and behavioral cues of pain, non-pain related distress, and adequacy of analgesia and sedation in mechanically ventilated pediatric patients, and evaluate these instruments in terms of their psychometric properties. A systematic review of original and validation reports of objective instruments to measure pain and non-pain related distress, and adequacy of analgesia and sedation in mechanically ventilated PICU patients was undertaken. A comprehensive search was conducted in 10 databases from January 1970 to June 2011. Reference lists of relevant articles were reviewed to identify additional articles. Studies were included in the review if they met pre-established eligibility criteria. Two independent reviewers reviewed studies for inclusion, assessed quality, and extracted data. Twenty-five articles were included, identifying 15 instruments. The instruments had different foci including: assessing pain, non-pain related distress, and sedation (n=2); assessing pain exclusively (n=4); assessing sedation exclusively (n=7), assessing sedation in mechanically ventilated muscle relaxed PICU patients (n=1); and assessing delirium in mechanically ventilated PICU patients (n=1). The Comfort Scale demonstrated the greatest clinical utility in the assessment of pain, non-pain related distress, and sedation in mechanically ventilated pediatric patients. Modified FLACC and the MAPS are more appropriate, however, for the assessment of procedural pain and other brief painful events. More work is required on instruments for the assessment of distress in mechanically ventilated muscle relaxed PICU patients, and the assessment of delirium in PICU patients. This review provides essential information to guide PICU clinicians in choosing instruments to assess pain, non-pain related distress, and adequacy of analgesia and sedation in mechanically ventilated pediatric patients. Effective knowledge translation is essential in the implementation, adoption, and successful use of these instruments. Copyright © 2013 Elsevier Ltd. All rights reserved.

Iterative integral parameter identification of a respiratory mechanics model.

PubMed

Schranz, Christoph; Docherty, Paul D; Chiew, Yeong Shiong; Möller, Knut; Chase, J Geoffrey

2012-07-18

Patient-specific respiratory mechanics models can support the evaluation of optimal lung protective ventilator settings during ventilation therapy. Clinical application requires that the individual's model parameter values must be identified with information available at the bedside. Multiple linear regression or gradient-based parameter identification methods are highly sensitive to noise and initial parameter estimates. Thus, they are difficult to apply at the bedside to support therapeutic decisions. An iterative integral parameter identification method is applied to a second order respiratory mechanics model. The method is compared to the commonly used regression methods and error-mapping approaches using simulated and clinical data. The clinical potential of the method was evaluated on data from 13 Acute Respiratory Distress Syndrome (ARDS) patients. The iterative integral method converged to error minima 350 times faster than the Simplex Search Method using simulation data sets and 50 times faster using clinical data sets. Established regression methods reported erroneous results due to sensitivity to noise. In contrast, the iterative integral method was effective independent of initial parameter estimations, and converged successfully in each case tested. These investigations reveal that the iterative integral method is beneficial with respect to computing time, operator independence and robustness, and thus applicable at the bedside for this clinical application.

Advanced Clinical Decision Support for Transport of the Critically Ill Patient

DTIC Science & Technology

2012-10-01

status   epilepticus ...2013   Q2   2013   Q3   Status   1                   On  Schedule   1a...ii. status  asthmaticus,     iii. sedation  and  analgesia,     iv. mechanical  ventilator  management  for  children

Sulforhodamine B interacts with albumin to lower surface tension and protect against ventilation injury of flooded alveoli

PubMed Central

Kharge, Angana Banerjee; Wu, You

2014-01-01

In the acute respiratory distress syndrome, alveolar flooding by proteinaceous edema liquid impairs gas exchange. Mechanical ventilation is used as a supportive therapy. In regions of the edematous lung, alveolar flooding is heterogeneous, and stress is concentrated in aerated alveoli. Ventilation exacerbates stress concentrations and injuriously overexpands aerated alveoli. Injury degree is proportional to surface tension, T. Lowering T directly lessens injury. Furthermore, as heterogeneous flooding causes the stress concentrations, promoting equitable liquid distribution between alveoli should, indirectly, lessen injury. We present a new theoretical analysis suggesting that liquid is trapped in discrete alveoli by a pressure barrier that is proportional to T. Experimentally, we identify two rhodamine dyes, sulforhodamine B and rhodamine WT, as surface active in albumin solution and investigate whether the dyes lessen ventilation injury. In the isolated rat lung, we micropuncture a surface alveolus, instill albumin solution, and obtain an area with heterogeneous alveolar flooding. We demonstrate that rhodamine dye addition lowers T, reduces ventilation-induced injury, and facilitates liquid escape from flooded alveoli. In vitro we show that rhodamine dye is directly surface active in albumin solution. We identify sulforhodamine B as a potential new therapeutic agent for the treatment of the acute respiratory distress syndrome. PMID:25414246

Respiratory muscle activity and patient–ventilator asynchrony during different settings of noninvasive ventilation in stable hypercapnic COPD: does high inspiratory pressure lead to respiratory muscle unloading?

PubMed Central

Duiverman, Marieke L; Huberts, Anouk S; van Eykern, Leo A; Bladder, Gerrie; Wijkstra, Peter J

2017-01-01

Introduction High-intensity noninvasive ventilation (NIV) has been shown to improve outcomes in stable chronic obstructive pulmonary disease patients. However, there is insufficient knowledge about whether with this more controlled ventilatory mode optimal respiratory muscle unloading is provided without an increase in patient–ventilator asynchrony (PVA). Patients and methods Ten chronic obstructive pulmonary disease patients on home mechanical ventilation were included. Four different ventilatory settings were investigated in each patient in random order, each for 15 min, varying the inspiratory positive airway pressure and backup breathing frequency. With surface electromyography (EMG), activities of the intercostal muscles, diaphragm, and scalene muscles were determined. Furthermore, pressure tracings were derived simultaneously in order to assess PVA. Results Compared to spontaneous breathing, the most pronounced decrease in EMG activity was achieved with the high-pressure settings. Adding a high breathing frequency did reduce EMG activity per breath, while the decrease in EMG activity over 1 min was comparable with the high-pressure, low-frequency setting. With high backup breathing frequencies less breaths were pressure supported (25% vs 97%). PVAs occurred more frequently with the low-frequency settings (P=0.017). Conclusion High-intensity NIV might provide optimal unloading of respiratory muscles, without undue increases in PVA. PMID:28138234

Respiratory muscle activity and patient-ventilator asynchrony during different settings of noninvasive ventilation in stable hypercapnic COPD: does high inspiratory pressure lead to respiratory muscle unloading?

PubMed

Duiverman, Marieke L; Huberts, Anouk S; van Eykern, Leo A; Bladder, Gerrie; Wijkstra, Peter J

2017-01-01

High-intensity noninvasive ventilation (NIV) has been shown to improve outcomes in stable chronic obstructive pulmonary disease patients. However, there is insufficient knowledge about whether with this more controlled ventilatory mode optimal respiratory muscle unloading is provided without an increase in patient-ventilator asynchrony (PVA). Ten chronic obstructive pulmonary disease patients on home mechanical ventilation were included. Four different ventilatory settings were investigated in each patient in random order, each for 15 min, varying the inspiratory positive airway pressure and backup breathing frequency. With surface electromyography (EMG), activities of the intercostal muscles, diaphragm, and scalene muscles were determined. Furthermore, pressure tracings were derived simultaneously in order to assess PVA. Compared to spontaneous breathing, the most pronounced decrease in EMG activity was achieved with the high-pressure settings. Adding a high breathing frequency did reduce EMG activity per breath, while the decrease in EMG activity over 1 min was comparable with the high-pressure, low-frequency setting. With high backup breathing frequencies less breaths were pressure supported (25% vs 97%). PVAs occurred more frequently with the low-frequency settings ( P =0.017). High-intensity NIV might provide optimal unloading of respiratory muscles, without undue increases in PVA.

A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure

PubMed Central

Chang, Suchi; Shi, Jindong; Fu, Cuiping; Wu, Xu; Li, Shanqun

2016-01-01

Background COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Intensive care unit patients with acute exacerbations of COPD requiring mechanical ventilation have higher mortality rates than other hospitalized patients. Although mechanical ventilation is the most effective intervention for these conditions, invasive ventilation techniques have yielded variable effects. Objective We evaluated pressure-regulated volume control (PRVC) ventilation treatment efficacy and preventive effects on pulmonary barotrauma in elderly COPD patients with respiratory failure. Patients and methods Thirty-nine intubated patients were divided into experimental and control groups and treated with the PRVC and synchronized intermittent mandatory ventilation – volume control methods, respectively. Vital signs, respiratory mechanics, and arterial blood gas analyses were monitored for 2–4 hours and 48 hours. Results Both groups showed rapidly improved pH, partial pressure of oxygen (PaO2), and PaO2 per fraction of inspired O2 levels and lower partial pressure of carbon dioxide (PaCO2) levels. The pH and PaCO2 levels at 2–4 hours were lower and higher, respectively, in the test group than those in the control group (P<0.05 for both); after 48 hours, blood gas analyses showed no statistical difference in any marker (P>0.05). Vital signs during 2–4 hours and 48 hours of treatment showed no statistical difference in either group (P>0.05). The level of peak inspiratory pressure in the experimental group after mechanical ventilation for 2–4 hours and 48 hours was significantly lower than that in the control group (P<0.05), while other variables were not significantly different between groups (P>0.05). Conclusion Among elderly COPD patients with respiratory failure, application of PRVC resulted in rapid improvement in arterial blood gas analyses while maintaining a low peak inspiratory pressure. PRVC can reduce pulmonary barotrauma risk, making it a safer protective ventilation mode than synchronized intermittent mandatory ventilation – volume control. PMID:27274223

A comparison of synchronized intermittent mandatory ventilation and pressure-regulated volume control ventilation in elderly patients with acute exacerbations of COPD and respiratory failure.

PubMed

Chang, Suchi; Shi, Jindong; Fu, Cuiping; Wu, Xu; Li, Shanqun

2016-01-01

COPD is the third leading cause of death worldwide. Acute exacerbations of COPD may cause respiratory failure, requiring intensive care unit admission and mechanical ventilation. Intensive care unit patients with acute exacerbations of COPD requiring mechanical ventilation have higher mortality rates than other hospitalized patients. Although mechanical ventilation is the most effective intervention for these conditions, invasive ventilation techniques have yielded variable effects. We evaluated pressure-regulated volume control (PRVC) ventilation treatment efficacy and preventive effects on pulmonary barotrauma in elderly COPD patients with respiratory failure. Thirty-nine intubated patients were divided into experimental and control groups and treated with the PRVC and synchronized intermittent mandatory ventilation - volume control methods, respectively. Vital signs, respiratory mechanics, and arterial blood gas analyses were monitored for 2-4 hours and 48 hours. Both groups showed rapidly improved pH, partial pressure of oxygen (PaO2), and PaO2 per fraction of inspired O2 levels and lower partial pressure of carbon dioxide (PaCO2) levels. The pH and PaCO2 levels at 2-4 hours were lower and higher, respectively, in the test group than those in the control group (P<0.05 for both); after 48 hours, blood gas analyses showed no statistical difference in any marker (P>0.05). Vital signs during 2-4 hours and 48 hours of treatment showed no statistical difference in either group (P>0.05). The level of peak inspiratory pressure in the experimental group after mechanical ventilation for 2-4 hours and 48 hours was significantly lower than that in the control group (P<0.05), while other variables were not significantly different between groups (P>0.05). Among elderly COPD patients with respiratory failure, application of PRVC resulted in rapid improvement in arterial blood gas analyses while maintaining a low peak inspiratory pressure. PRVC can reduce pulmonary barotrauma risk, making it a safer protective ventilation mode than synchronized intermittent mandatory ventilation - volume control.

Clinical outcome associated with the use of different inhalation method with and without humidification in asthmatic mechanically ventilated patients.

PubMed

Moustafa, Islam O F; ElHansy, Muhammad H E; Al Hallag, Moataz; Fink, James B; Dailey, Patricia; Rabea, Hoda; Abdelrahim, Mohamed E A

2017-08-01

Inhaled-medication delivered during mechanical-ventilation is affected by type of aerosol-generator and humidity-condition. Despite many in-vitro studies related to aerosol-delivery to mechanically-ventilated patients, little has been reported on clinical effects of these variables. The aim of this study was to determine effect of humidification and type of aerosol-generator on clinical status of mechanically ventilated asthmatics. 72 (36 females) asthmatic subjects receiving invasive mechanical ventilation were enrolled and assigned randomly to 6 treatment groups of 12 (6 females) subjects each received, as possible, all inhaled medication using their assigned aerosol generator and humidity condition during delivery. Aerosol-generators were placed immediately after humidifier within inspiratory limb of mechanical ventilation circuit. First group used vibrating-mesh-nebulizer (Aerogen Solo; VMN) with humidification; Second used VMN without humidification; Third used metered-dose-inhaler with AeroChamber Vent (MDI-AV) with humidification; Forth used MDI-AV without humidification; Fifth used Oxycare jet-nebulizer (JN) with humidification; Sixth used JN without humidification. Measured parameters included clinical-parameters reflected patient response (CP) and endpoint parameters e.g. length-of-stay in the intensive-care-unit (ICU-days) and mechanical-ventilation days (MV-days). There was no significant difference between studied subjects in the 6 groups in baseline of CP. VMN resulted in trend to shorter ICU-days (∼1.42days) compared to MDI-AV (p = 0.39) and relatively but not significantly shorter ICU-days (∼0.75days) compared JN. Aerosol-delivery with or without humidification did not have any significant effect on any of parameters studied with very light insignificant tendency of delivery at humid condition to decrease MV-days and ICU-days. No significant effect was found of changing humidity during aerosol-delivery to ventilated-patient. VMN to deliver aerosol in ventilated patient resulted in trend to decreased ICU-days compared to JN and MDI-AV. Aerosol-delivery with or without humidification did not have any significant effect on any of parameters studied. However, we recommend increasing the number of patients studied to corroborate this finding. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sleep Disturbances in Patients Admitted to a Step-Down Unit After ICU Discharge: the Role of Mechanical Ventilation

PubMed Central

Fanfulla, Francesco; Ceriana, Piero; D'Artavilla Lupo, Nadia; Trentin, Rossella; Frigerio, Francesco; Nava, Stefano

2011-01-01

Background: Severe sleep disruption is a well-documented problem in mechanically ventilated, critically ill patients during their time in the intensive care unit (ICU), but little attention has been paid to the period when these patients become clinically stable and are transferred to a step-down unit (SDU). We monitored the 24-h sleep pattern in 2 groups of patients, one on mechanical ventilation and the other breathing spontaneously, admitted to our SDU to assess the presence of sleep abnormalities and their association with mechanical ventilation. Methods: Twenty-two patients admitted to an SDU underwent 24-h polysomnography with monitoring of noise and light. Results: One patient did not complete the study. At night, 10 patients showed reduced sleep efficiency, 6 had reduced percentage of REM sleep, and 3 had reduced percentage of slow wave sleep (SWS). Sleep amount and quality did not differ between patients breathing spontaneously and those on mechanical ventilation. Clinical severity (SAPSII score) was significantly correlated with daytime total sleep time and efficiency (r = 0.51 and 0.5, P < 0.05, respectively); higher pH was correlated with reduced sleep quantity and quality; and higher PaO2 was correlated with increased SWS (r = 0.49; P = 0.02). Conclusions: Patients admitted to an SDU after discharge from an ICU still have a wide range of sleep abnormalities. These abnormalities are mainly associated with a high severity score and alkalosis. Mechanical ventilation does not appear to be a primary cause of sleep impairment. Citation: Fanfulla F; Ceriana P; Lupo ND; Trentin R; Frigerio F; Nava S. Sleep disturbances in patients admitted to a step-down unit after ICU discharge: the role of mechanical ventilation. SLEEP 2011;34(3):355-362. PMID:21358853

Prolonged Mechanical Ventilation as a Predictor of Mortality After Cardiac Surgery.

PubMed

Fernandez-Zamora, Maria Dolores; Gordillo-Brenes, Antonio; Banderas-Bravo, Esther; Arboleda-Sánchez, José Andrés; Hinojosa-Pérez, Rafael; Aguilar-Alonso, Eduardo; Herruzo-Aviles, Ángel; Curiel-Balsera, Emilio; Sánchez-Rodríguez, Ángel; Rivera-Fernández, Ricardo

2018-05-01

Mortality among the small percentage of cardiac surgery patients receiving prolonged mechanical ventilation is high, but this issue appears to be inadequately addressed in guidelines. This study is a retrospective analysis of prospective, multi-center, and observational study in Spain including all adults undergoing cardiac surgery in 3 Andalusian hospitals between June 2008 and December 2012. The study included 3,588 adults with mean ± SD age of 63.5 ± 12.8 y and with median (interquartile range) EuroSCORE of 5 (3-7) points. Prolonged mechanical ventilation (> 24 h) was required by 415 subjects (11.6%), with ICU mortality of 44.3% (184 subjects), and was not required by 3,173 subjects (88.4%), with ICU mortality of 3.1% (99 subjects, P < .001). Prolonged mechanical ventilation was associated with more complications and was required by 4.5% of subjects with a EuroSCORE <5, 11.2% with a score of 5-7, 27.2% with a score of 8-10, and 32.2% with a score > 10. In the multivariable analysis, ICU mortality was associated with illness severity, duration of bypass surgery, surgery type, and prolonged mechanical ventilation (odds ratio 15.19, 95% CI 11.56-22.09). The main cause of death was multiple organ failure and sepsis in subjects who required prolonged mechanical ventilation (50.3%) and cardiogenic shock in those who did not (59.2%). Prolonged postoperative mechanical ventilation was required by 10-20% of cardiac surgery subjects, who constitute a specific group that represents most of the postoperative mortality, which is associated with multiple organ failure and sepsis. Copyright © 2018 by Daedalus Enterprises.

Open lung approach vs acute respiratory distress syndrome network ventilation in experimental acute lung injury.

PubMed

Spieth, P M; Güldner, A; Carvalho, A R; Kasper, M; Pelosi, P; Uhlig, S; Koch, T; Gama de Abreu, M

2011-09-01

Setting and strategies of mechanical ventilation with positive end-expiratory pressure (PEEP) in acute lung injury (ALI) remains controversial. This study compares the effects between lung-protective mechanical ventilation according to the Acute Respiratory Distress Syndrome Network recommendations (ARDSnet) and the open lung approach (OLA) on pulmonary function and inflammatory response. Eighteen juvenile pigs were anaesthetized, mechanically ventilated, and instrumented. ALI was induced by surfactant washout. Animals were randomly assigned to mechanical ventilation according to the ARDSnet protocol or the OLA (n=9 per group). Gas exchange, haemodynamics, pulmonary blood flow (PBF) distribution, and respiratory mechanics were measured at intervals and the lungs were removed after 6 h of mechanical ventilation for further analysis. PEEP and mean airway pressure were higher in the OLA than in the ARDSnet group [15 cmH(2)O, range 14-18 cmH(2)O, compared with 12 cmH(2)O; 20.5 (sd 2.3) compared with 18 (1.4) cmH(2)O by the end of the experiment, respectively], and OLA was associated with improved oxygenation compared with the ARDSnet group after 6 h. OLA showed more alveolar overdistension, especially in gravitationally non-dependent regions, while the ARDSnet group was associated with more intra-alveolar haemorrhage. Inflammatory mediators and markers of lung parenchymal stress did not differ significantly between groups. The PBF shifted from ventral to dorsal during OLA compared with ARDSnet protocol [-0.02 (-0.09 to -0.01) compared with -0.08 (-0.12 to -0.06), dorsal-ventral gradients after 6 h, respectively]. According to the OLA, mechanical ventilation improved oxygenation and redistributed pulmonary perfusion when compared with the ARDSnet protocol, without differences in lung inflammatory response.

The Association Between Daytime Intensivist Physician Staffing and Mortality in the Context of Other ICU Organizational Practices: A Multicenter Cohort Study.

PubMed

Costa, Deena Kelly; Wallace, David J; Kahn, Jeremy M

2015-11-01

Daytime intensivist physician staffing is associated with improved outcomes in the ICU. However, it is unclear whether this association persists in the era of interprofessional, protocol-directed critical care. We sought to reexamine the association between daytime intensivist physician staffing and ICU mortality and determine if interprofessional rounding and protocols for mechanical ventilation in part mediate this relationship. Retrospective cohort study of ICUs in the Acute Physiology and Chronic Health Evaluation clinical information system from 2009 to 2010. Forty-nine ICUs in 25 U.S. hospitals. Adults (17 yr and older) admitted to a study ICU. None. We defined high-intensity daytime intensivist staffing as either a mandatory consult or closed ICU model; interprofessional rounds as rounds that included a respiratory therapist, pharmacist, physician and nurse; and protocol use as having protocols for liberation from mechanical ventilation and lung protective mechanical ventilation. Using multivariable logistic regression, we estimated the independent effect of daytime intensivist physician staffing on in-hospital mortality controlling for interprofessional rounds and protocols for mechanical ventilation, as well as other patient and hospital characteristics. Twenty-seven ICUs (55%) reported high-intensity daytime physician staffing, 42 ICUs (85%) reported daily interprofessional rounds, and 31 (63%) reported having protocols for mechanical ventilation. There was no association between daytime intensivist physician staffing and in-hospital mortality (adjusted odds ratio, 0.86; 95% CI, 0.65-1.14). After adjusting for interprofessional rounds and protocols for mechanical ventilation, the effect of daytime intensivist physician staffing remained nonsignificant (adjusted odds ratio, 0.90; 95% CI, 0.70-1.17). High-intensity daytime physician staffing in the ICU was not significantly associated with lower mortality in a modern cohort. This association was not affected by interprofessional rounds or protocols for mechanical ventilation.

Optimal support techniques when providing mechanical ventilation to patients with acute respiratory distress syndrome.

PubMed

Parissopoulos, Stelios; Mpouzika, Meropi DA; Timmins, Fiona

2017-01-01

Adult respiratory distress syndrome (ARDS) is a type of acute diffuse lung injury characterized by severe inflammation, increased pulmonary vascular permeability and a loss of aerated lung tissue. The effects of high fraction of inspired oxygen (FiO 2 ) include oxygen toxicity manifested by damage to the lung parenchyma in the acute phase of lung injury. There is still a high mortality rate among this group of patients, so clinically sensitive evidence-based interventions are paramount to maximize survival chances during critical care. The aim of this article is to explore the current opinion concerning optimal mechanical ventilation support techniques for patients with acute respiratory distress syndrome. A literature search of clinical trials and observation studies, reviews, discussion papers, meta-analyses and clinical guidelines written in English up to 2015, derived from the databases of Scopus, CINAHL, Cochrane Library databases and PubMed was conducted. Low tidal volume, pressure limitation and prone positioning in severe ARDS patients appear to be of some benefit. More research is required and further development and use of standardized protocols is an important strategy for reducing practice variations across disciplines, as well as giving clear guidelines to nurses practising in critical care. There is also evidence that this syndrome is under-diagnosed and the utilization of lung protective ventilation is still variable. It is important that nurses have underlying knowledge of both aetiology of ARDS and ventilation management, and that they monitor patients very closely. The adoption of a low tidal ventilation protocol, which is based on quality evidence guidelines, the value of rescue therapies and patient observation practices in the overall patient management, and the need to place emphasis on long-term patient outcomes, all these emerge as key factors for consideration and future research. However, there is also a need for more research that would explore the unique contribution of nurses in the management of this patient group, as it is difficult to discern this in the current literature. © 2015 British Association of Critical Care Nurses.

Driving Pressure and Hospital Mortality in Patients Without ARDS: A Cohort Study.

PubMed

Schmidt, Marcello F S; Amaral, Andre C K B; Fan, Eddy; Rubenfeld, Gordon D

2018-01-01

Driving pressure (ΔP) is associated with mortality in patients with ARDS and with pulmonary complications in patients undergoing general anesthesia. Whether ΔP is associated with outcomes of patients without ARDS who undergo ventilation in the ICU is unknown. Our objective was to determine the independent association between ΔP and outcomes in mechanically ventilated patients without ARDS on day 1 of mechanical ventilation. This was a retrospective analysis of a cohort of 622 mechanically ventilated adult patients without ARDS on day 1 of mechanical ventilation from five ICUs in a tertiary center in the United States. The primary outcome was hospital mortality. The presence of ARDS was determined using the minimum daily Pao 2 to Fio 2 (PF) ratio and an automated text search of chest radiography reports. The data set was validated by first testing the model in 543 patients with ARDS. In patients without ARDS on day 1 of mechanical ventilation, ΔP was not independently associated with hospital mortality (OR, 1.01; 95% CI, 0.97-1.05). The results of the primary analysis were confirmed in a series of preplanned sensitivity analyses. In this cohort of patients without ARDS on day 1 of mechanical ventilation and within the limits of ventilatory settings normally used by clinicians, ΔP was not associated with hospital mortality. This study also confirms the association between ΔP and mortality in patients with ARDS not enrolled in a trial and in hypoxemic patients without ARDS. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Prolonged weaning: from the intensive care unit to home.

PubMed

Navalesi, P; Frigerio, P; Patzlaff, A; Häußermann, S; Henseke, P; Kubitschek, M

2014-01-01

Weaning is the process of withdrawing mechanical ventilation which starts with the first spontaneous breathing trial (SBT). Based on the degree of difficulty and duration, weaning is classified as simple, difficult and prolonged. Prolonged weaning, which includes patients who fail 3 SBTs or are still on mechanical ventilation 7 days after the first SBT, affects a relatively small fraction of mechanically ventilated ICU patients but these, however, requires disproportionate resources. There are several potential causes which can lead to prolonged weaning. It is nonetheless important to understand the problem from the point of view of each individual patient in order to adopt appropriate treatment and define precise prognosis. An otherwise stable patient who remains on mechanical ventilation will be considered for transfer to a specialized weaning unit (SWU). Though there is not a precise definition, SWU can be considered as highly specialized and protected environments for patients requiring mechanical ventilation despite resolution of the acute disorder. Proper staffing, well defined short-term and long-term goals, attention to psychological and social problems represent key determinants of SWU success. Some patients cannot be weaned, either partly or entirely, and may require long-term home mechanical ventilation. In these cases the logistics relating to caregivers and the equipment must be carefully considered and addressed. Copyright © 2014 Sociedade Portuguesa de Pneumologia. Published by Elsevier España. All rights reserved.

Mechanical Ventilation-Related Safety Incidents in General Care Wards and ICU Settings.

PubMed

Kamio, Tadashi; Masamune, Ken

2018-05-29

Although the ICU is the most appropriate place to care for mechanically ventilated patients, a considerable number are ventilated in general medical care wards all over the world. However, adverse events focusing on mechanically ventilated patients in general care have not been explored. Data from the Japan Council for Quality Health Care database were analyzed. Patient safety incidents from January 2010 to November 2017 regarding mechanical ventilation were collected, and comparisons of patient safety incidents between ICUs/high care units (HCUs) and general care wards were made. We identified 261 adverse events (with at least 20 adverse events resulting in death) and 702 near-miss events related to mechanical ventilation in Japan between 2010 and 2017. Furthermore, among all adverse events, 19% (49 of 261 events) caused serious harm (residual disability or death). Human-factor issues were most frequent in both ICU/HCU and general care settings (55% and 53%, respectively), while knowledge-based errors were higher in the general care setting. Human-factor issues were the most frequent reasons in both settings, while knowledge-based error rates were higher in general care. Our results suggest that proper education and training is needed to minimize patient safety incidents in facilities without respiratory therapists. Copyright © 2018 by Daedalus Enterprises.

Tracheo-bronchitis and pneumonia associated with mechanical ventilation by Chryseobacterium indologenes.

PubMed

González-Castro, A; Alsasua, A; Peñasco, Y; Rodríguez, J C; Duerto, J

2017-05-01

The development of nosocomial infections by germs resistant to carbapenems inherently increases mortality, and causes an increase in health spending. The knowledge and study of these infections is important in improving epidemiological and therapeutic performance protocols. We present a descriptive study of eight patients diagnosed with tracheobronchitis (TAVM) and pneumonia (NAVM) associated with mechanical ventilation Chryseobacterium indologenes (CBI), over a period of five years. CBI isolation occurred at 11 days on average (rank 7-18) of remaining patients connected to mechanical ventilation. The average length of patients on mechanical ventilation was 36 days (range 10-140). The average ICU stay was 49 days (range 14-180). There was no death at 28 days, but the intra-hospital mortality was 2 cases (25%). Nosocomial respiratory infection secondary to CBI in mechanically ventilated patients has increased in recent years, so that should be included in the differential diagnostic of NAMV. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Risk factors associated with development of ventilator associated pneumonia.

PubMed

Noor, Ahmed; Hussain, Syed Fayyaz

2005-02-01

To assess the risk factors associated with development of ventilator associated pneumonia (VAP). A case control study. Intensive Care Unit (ICU) at the Aga Khan University Hospital, Karachi, between January 1999 and June 2000. All patients with assisted mechanical ventilation were assessed for the development of VAP. Risk factors associated with development of VAP were determined. Adult patients who developed pneumonia, 48 hours after ventilation, were called cases while those who did not develop pneumonia were called controls. Seventy (28%) out of 250 mechanically ventilated patients developed VAP (rate of VAP was 26 cases per 1000 ventilator days). Shock during first 48 hours of ventilation (odds ratio (OR), 5.95; 95% confidence interval (CI), 2.83-12.52), transport out of ICU during mechanical ventilation (OR, 6.0; 95% CI, 2.92-12.37), re-intubation (OR, 4.23; 95% CI, 2.53-9.85), prior episode of aspiration of gastric content (OR, 3.07; 95% CI, 1.35-7.01), and use of antibiotics prior to intubation (OR,2.55; 95% CI, 1.20-5.41) were found to be independently associated with a higher risk of developing VAP. Gram negative organisms and Staphylococcus aureus were responsible for over 90% of cases. Patients with VAP had higher crude mortality rate (57.1%) compared with controls (32.2%). Ventilator associated pneumonia is associated with a high mortality. This study has identified risk factors associated with VAP.

Bundles to prevent ventilator-associated pneumonia: how valuable are they?

PubMed

Wip, Charity; Napolitano, Lena

2009-04-01

To review the value of care bundles to prevent ventilator-associated pneumonia (VAP). The Ventilator Bundle contains four components, elevation of the head of the bed to 30-45 degrees, daily 'sedation vacation' and daily assessment of readiness to extubate, peptic ulcer disease prophylaxis, and deep venous thrombosis prophylaxis, aimed to improve outcome in mechanically ventilated patients, but not all are associated with VAP prevention. Daily spontaneous awakening and breathing trials are associated with early liberation from mechanical ventilation and VAP reduction. Although a small prospective, randomized clinical study documented that the semirecumbent position was associated with a significant reduction in VAP, more recent studies have documented that the semirecumbent position is difficult to maintain in mechanically ventilated patients and may not impact VAP reduction. Prophylaxis for peptic ulcer disease and deep venous thrombosis do not directly impact VAP reduction. Other methods to reduce VAP, such as oral care and hygiene, chlorhexidine in the posterior pharynx, and specialized endotracheal tubes (continuous aspiration of subglottic secretions, silver-coated), should be considered for inclusion in a revised Ventilator Bundle more specifically aimed at VAP prevention. The Ventilator Bundle is an effective method to reduce VAP rates in ICUs. The ventilator bundle should be modified and expanded to include specific processes of care that have been definitively demonstrated to be effective in VAP reduction or a specific VAP bundle created to focus on VAP prevention.

Accelerated deflation promotes homogeneous airspace liquid distribution in the edematous lung.

PubMed

Wu, You; Nguyen, Tam L; Perlman, Carrie E

2017-04-01

Edematous lungs contain regions with heterogeneous alveolar flooding. Liquid is trapped in flooded alveoli by a pressure barrier-higher liquid pressure at the border than in the center of flooded alveoli-that is proportional to surface tension, T Stress is concentrated between aerated and flooded alveoli, to a degree proportional to T Mechanical ventilation, by cyclically increasing T , injuriously exacerbates stress concentrations. Overcoming the pressure barrier to redistribute liquid more homogeneously between alveoli should reduce stress concentration prevalence and ventilation injury. In isolated rat lungs, we test whether accelerated deflation can overcome the pressure barrier and catapult liquid out of flooded alveoli. We generate a local edema model with normal T by microinfusing liquid into surface alveoli. We generate a global edema model with high T by establishing hydrostatic edema, which does not alter T , and then gently ventilating the edematous lungs, which increases T at 15 cmH 2 O transpulmonary pressure by 52%. Thus ventilation of globally edematous lungs increases T , which should increase stress concentrations and, with positive feedback, cause escalating ventilation injury. In the local model, when the pressure barrier is moderate, accelerated deflation causes liquid to escape from flooded alveoli and redistribute more equitably. Flooding heterogeneity tends to decrease. In the global model, accelerated deflation causes liquid escape, but-because of elevated T -the liquid jumps to nearby, aerated alveoli. Flooding heterogeneity is unaltered. In pulmonary edema with normal T , early ventilation with accelerated deflation might reduce the positive feedback mechanism through which ventilation injury increases over time. NEW & NOTEWORTHY We introduce, in the isolated rat lung, a new model of pulmonary edema with elevated surface tension. We first generate hydrostatic edema and then ventilate gently to increase surface tension. We investigate the mechanical mechanisms through which 1 ) ventilation injures edematous lungs and 2 ) ventilation with accelerated deflation might lessen ventilation injury. Copyright © 2017 the American Physiological Society.

Accelerated deflation promotes homogeneous airspace liquid distribution in the edematous lung

PubMed Central

Wu, You; Nguyen, Tam L.

2017-01-01

Edematous lungs contain regions with heterogeneous alveolar flooding. Liquid is trapped in flooded alveoli by a pressure barrier—higher liquid pressure at the border than in the center of flooded alveoli—that is proportional to surface tension, T. Stress is concentrated between aerated and flooded alveoli, to a degree proportional to T. Mechanical ventilation, by cyclically increasing T, injuriously exacerbates stress concentrations. Overcoming the pressure barrier to redistribute liquid more homogeneously between alveoli should reduce stress concentration prevalence and ventilation injury. In isolated rat lungs, we test whether accelerated deflation can overcome the pressure barrier and catapult liquid out of flooded alveoli. We generate a local edema model with normal T by microinfusing liquid into surface alveoli. We generate a global edema model with high T by establishing hydrostatic edema, which does not alter T, and then gently ventilating the edematous lungs, which increases T at 15 cmH2O transpulmonary pressure by 52%. Thus ventilation of globally edematous lungs increases T, which should increase stress concentrations and, with positive feedback, cause escalating ventilation injury. In the local model, when the pressure barrier is moderate, accelerated deflation causes liquid to escape from flooded alveoli and redistribute more equitably. Flooding heterogeneity tends to decrease. In the global model, accelerated deflation causes liquid escape, but—because of elevated T—the liquid jumps to nearby, aerated alveoli. Flooding heterogeneity is unaltered. In pulmonary edema with normal T, early ventilation with accelerated deflation might reduce the positive feedback mechanism through which ventilation injury increases over time. NEW & NOTEWORTHY We introduce, in the isolated rat lung, a new model of pulmonary edema with elevated surface tension. We first generate hydrostatic edema and then ventilate gently to increase surface tension. We investigate the mechanical mechanisms through which 1) ventilation injures edematous lungs and 2) ventilation with accelerated deflation might lessen ventilation injury. PMID:27979983

Home mechanical ventilation in Canada: a national survey.

PubMed

Rose, Louise; McKim, Douglas A; Katz, Sherri L; Leasa, David; Nonoyama, Mika; Pedersen, Cheryl; Goldstein, Roger S; Road, Jeremy D

2015-05-01

No comprehensive Canadian national data describe the prevalence of and service provision for ventilator-assisted individuals living at home, data critical to health-care system planning for appropriate resourcing. Our objective was to generate national data profiling service providers, users, types of services, criteria for initiation and monitoring, ventilator servicing arrangements, education, and barriers to home transition. Eligible providers delivering services to ventilator-assisted individuals (adult and pediatric) living at home were identified by our national provider inventory and referrals from other providers. The survey was administered via a web link from August 2012 to April 2013. The survey response rate was 152/171 (89%). We identified 4,334 ventilator-assisted individuals: an estimated prevalence of 12.9/100,000 population, with 73% receiving noninvasive ventilation (NIV) and 18% receiving intermittent mandatory ventilation (9% not reported). Services were delivered by 39 institutional providers and 113 community providers. We identified variation in initiation criteria for NIV, with polysomnography demonstrating nocturnal hypoventilation (57%), daytime hypercapnia (38%), and nocturnal hypercapnia (32%) as the most common criteria. Various models of ventilator servicing were reported. Most providers (64%) stated that caregiver competency was a prerequisite for home discharge; however, repeated competency assessment and retraining were offered by only 45%. Important barriers to home transition were: insufficient funding for paid caregivers, equipment, and supplies; a shortage of paid caregivers; and negotiating public funding arrangements. Ventilatory support in the community appears well-established, with most individuals managed with NIV. Although caregiver competency is a prerequisite to discharge, ongoing assessment and retraining were infrequent. Funding and caregiver availability were important barriers to home transition. Copyright © 2015 by Daedalus Enterprises.

Informatics infrastructure for syndrome surveillance, decision support, reporting, and modeling of critical illness.

PubMed

Herasevich, Vitaly; Pickering, Brian W; Dong, Yue; Peters, Steve G; Gajic, Ognjen

2010-03-01

To develop and validate an informatics infrastructure for syndrome surveillance, decision support, reporting, and modeling of critical illness. Using open-schema data feeds imported from electronic medical records (EMRs), we developed a near-real-time relational database (Multidisciplinary Epidemiology and Translational Research in Intensive Care Data Mart). Imported data domains included physiologic monitoring, medication orders, laboratory and radiologic investigations, and physician and nursing notes. Open database connectivity supported the use of Boolean combinations of data that allowed authorized users to develop syndrome surveillance, decision support, and reporting (data "sniffers") routines. Random samples of database entries in each category were validated against corresponding independent manual reviews. The Multidisciplinary Epidemiology and Translational Research in Intensive Care Data Mart accommodates, on average, 15,000 admissions to the intensive care unit (ICU) per year and 200,000 vital records per day. Agreement between database entries and manual EMR audits was high for sex, mortality, and use of mechanical ventilation (kappa, 1.0 for all) and for age and laboratory and monitored data (Bland-Altman mean difference +/- SD, 1(0) for all). Agreement was lower for interpreted or calculated variables, such as specific syndrome diagnoses (kappa, 0.5 for acute lung injury), duration of ICU stay (mean difference +/- SD, 0.43+/-0.2), or duration of mechanical ventilation (mean difference +/- SD, 0.2+/-0.9). Extraction of essential ICU data from a hospital EMR into an open, integrative database facilitates process control, reporting, syndrome surveillance, decision support, and outcome research in the ICU.

Respiratory mechanics in mechanically ventilated patients.

PubMed

Hess, Dean R

2014-11-01

Respiratory mechanics refers to the expression of lung function through measures of pressure and flow. From these measurements, a variety of derived indices can be determined, such as volume, compliance, resistance, and work of breathing. Plateau pressure is a measure of end-inspiratory distending pressure. It has become increasingly appreciated that end-inspiratory transpulmonary pressure (stress) might be a better indicator of the potential for lung injury than plateau pressure alone. This has resulted in a resurgence of interest in the use of esophageal manometry in mechanically ventilated patients. End-expiratory transpulmonary pressure might also be useful to guide the setting of PEEP to counterbalance the collapsing effects of the chest wall. The shape of the pressure-time curve might also be useful to guide the setting of PEEP (stress index). This has focused interest in the roles of stress and strain to assess the potential for lung injury during mechanical ventilation. This paper covers both basic and advanced respiratory mechanics during mechanical ventilation. Copyright © 2014 by Daedalus Enterprises.

Pneumothorax - infants

MedlinePlus

... easily. If the baby needs a breathing machine (mechanical ventilator), extra pressure on the baby's lungs, from ... problems. If the baby needs a breathing machine (mechanical ventilator), extra pressure on the baby's lungs from ...

Lung Transplant

MedlinePlus

... in the hospital's intensive care unit (ICU). A mechanical ventilator will help you breathe for a few ... condition improves, you'll no longer need the mechanical ventilator, and you'll be moved out of ...

Risk factors for 2009 pandemic influenza A (H1N1)-related hospitalization and death among racial/ethnic groups in New Mexico.

PubMed

Thompson, Deborah L; Jungk, Jessica; Hancock, Emily; Smelser, Chad; Landen, Michael; Nichols, Megin; Selvage, David; Baumbach, Joan; Sewell, Mack

2011-09-01

We assessed risk factors for 2009 pandemic influenza A (H1N1)-related hospitalization, mechanical ventilation, and death among New Mexico residents. We calculated population rate ratios using Poisson regression to analyze risk factors for H1N1-related hospitalization. We performed a cross-sectional analysis of hospitalizations during September 14, 2009 through January 13, 2010, using logistic regression to assess risk factors for mechanical ventilation and death among those hospitalized. During the study period, 926 laboratory-confirmed H1N1-related hospitalizations were identified. H1N1-related hospitalization was significantly higher among American Indians (risk ratio [RR] = 2.6; 95% confidence interval [CI] = 2.2, 3.2), Blacks (RR = 1.7; 95% CI = 1.2, 2.4), and Hispanics (RR = 1.8; 95% CI = 1.5, 2.0) than it was among non-Hispanic Whites, and also was higher among persons of younger age and lower household income. Mechanical ventilation was significantly associated with age 25 years and older, obesity, and lack of or delayed antiviral treatment. Death was significantly associated with male gender, cancer during the previous 12 months, and liver disorder. This analysis supports recent national efforts to include American Indian/Alaska Native race as a group at high risk for complications of influenza with respect to vaccination and antiviral treatment recommendations.

Prevention of bronchopulmonary dysplasia in extremely low gestational age neonates: current evidence.

PubMed

Poets, Christian F; Lorenz, Laila

2018-05-01

Bronchopulmonary dysplasia (BPD) is one of the most frequent complications in extremely low gestational age neonates, but has remained largely unchanged in rate. We reviewed data on BPD prevention focusing on recent meta-analyses. Interventions with proven effectiveness in reducing BPD include the primary use of non-invasive respiratory support, the application of surfactant without endotracheal ventilation and the use of volume-targeted ventilation in infants requiring endotracheal intubation. Following extubation, synchronised nasal ventilation is more effective than continuous positive airway pressure in reducing BPD. Pharmacologically, commencing caffeine citrate on postnatal day 1 or 2 seems more effective than a later start. Applying intramuscular vitamin A for the first 4 weeks reduces BPD, but is expensive and painful and thus not widely used. Low-dose hydrocortisone for the first 10 days prevents BPD, but was associated with almost twice as many cases of late-onset sepsis in infants born at 24-25 weeks' gestation. Inhaled corticosteroids, despite reducing BPD, were associated with a higher mortality rate. Administering dexamethasone to infants still requiring mechanical ventilation around postnatal weeks 2-3 may represent the best trade-off between restricting steroids to infants at risk of BPD while still affording high efficacy. Finally, identifying infants colonised with ureaplasma and treating those requiring intubation and mechanical ventilation with azithromycin is another promising approach to BPD prevention. Further interventions yet only backed by cohort studies include exclusive breastmilk feeding and a better prevention of nosocomial infections. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Subglottic secretion drainage for the prevention of ventilator-associated pneumonia: a systematic review and meta-analysis.

PubMed

Muscedere, John; Rewa, Oleksa; McKechnie, Kyle; Jiang, Xuran; Laporta, Denny; Heyland, Daren K

2011-08-01

Aspiration of secretions containing bacterial pathogens into the lower respiratory tract is the main cause of ventilator-associated pneumonia. Endotracheal tubes with subglottic secretion drainage can potentially reduce this and, therefore, the incidence of ventilator-associated pneumonia. New evidence on subglottic secretion drainage as a preventive measure for ventilator-associated pneumonia has been recently published and to consider the evidence in totality, we conducted an updated systematic review and meta-analysis. We searched computerized databases, reference lists, and personal files. We included randomized clinical trials of mechanically ventilated patients comparing standard endotracheal tubes to those with subglottic secretion drainage and reporting on the occurrence of ventilator-associated pneumonia. Studies were meta-analyzed for the primary outcome of ventilator-associated pneumonia and secondary clinical outcomes. We identified 13 randomized clinical trials that met the inclusion criteria with a total of 2442 randomized patients. Of the 13 studies, 12 reported a reduction in ventilator-associated pneumonia rates in the subglottic secretion drainage arm; in meta-analysis, the overall risk ratio for ventilator-associated pneumonia was 0.55 (95% confidence interval, 0.46-0.66; p < .00001) with no heterogeneity (I = 0%). The use of subglottic secretion drainage was associated with reduced intensive care unit length of stay (-1.52 days; 95% confidence interval, -2.94 to -0.11; p = .03); decreased duration of mechanically ventilated (-1.08 days; 95% confidence interval, -2.04 to -0.12; p = .03), and increased time to first episode of ventilator-associated pneumonia (2.66 days; 95% confidence interval, 1.06-4.26; p = .001). There was no effect on adverse events or on hospital or intensive care unit mortality. In those at risk for ventilator-associated pneumonia, the use of endotracheal tubes with subglottic secretion drainage is effective for the prevention of ventilator-associated pneumonia and may be associated with reduced duration of mechanical ventilation and intensive care unit length of stay.

Comparison of exogenous surfactant therapy, mechanical ventilation with high end-expiratory pressure and partial liquid ventilation in a model of acute lung injury.

PubMed

Hartog, A; Vazquez de Anda, G F; Gommers, D; Kaisers, U; Verbrugge, S J; Schnabel, R; Lachmann, B

1999-01-01

We have compared three treatment strategies, that aim to prevent repetitive alveolar collapse, for their effect on gas exchange, lung mechanics, lung injury, protein transfer into the alveoli and surfactant system, in a model of acute lung injury. In adult rats, the lungs were ventilated mechanically with 100% oxygen and a PEEP of 6 cm H2O, and acute lung injury was induced by repeated lung lavage to obtain a PaO2 value < 13 kPa. Animals were then allocated randomly (n = 12 in each group) to receive exogenous surfactant therapy, ventilation with high PEEP (18 cm H2O), partial liquid ventilation or ventilation with low PEEP (8 cm H2O) (ventilated controls). Blood-gas values were measured hourly. At the end of the 4-h study, in six animals per group, pressure-volume curves were constructed and bronchoalveolar lavage (BAL) was performed, whereas in the remaining animals lung injury was assessed. In the ventilated control group, arterial oxygenation did not improve and protein concentration of BAL and conversion of active to non-active surfactant components increased significantly. In the three treatment groups, PaO2 increased rapidly to > 50 kPa and remained stable over the next 4 h. The protein concentration of BAL fluid increased significantly only in the partial liquid ventilation group. Conversion of active to non-active surfactant components increased significantly in the partial liquid ventilation group and in the group ventilated with high PEEP. In the surfactant group and partial liquid ventilation groups, less lung injury was found compared with the ventilated control group and the group ventilated with high PEEP. We conclude that although all three strategies improved PaO2 to > 50 kPa, the impact on protein transfer into the alveoli, surfactant system and lung injury differed markedly.

Physiologic response to varying levels of pressure support and neurally adjusted ventilatory assist in patients with acute respiratory failure.

PubMed

Colombo, Davide; Cammarota, Gianmaria; Bergamaschi, Valentina; De Lucia, Marta; Corte, Francesco Della; Navalesi, Paolo

2008-11-01

Neurally adjusted ventilatory assist (NAVA) is a new mode wherein the assistance is provided in proportion to diaphragm electrical activity (EAdi). We assessed the physiologic response to varying levels of NAVA and pressure support ventilation (PSV). ICU of a University Hospital. Fourteen intubated and mechanically ventilated patients. DESIGN AND PROTOCOL: Cross-over, prospective, randomized controlled trial. PSV was set to obtain a VT/kg of 6-8 ml/kg with an active inspiration. NAVA was matched with a dedicated software. The assistance was decreased and increased by 50% with both modes. The six assist levels were randomly applied. Arterial blood gases (ABGs), tidal volume (VT/kg), peak EAdi, airway pressure (Paw), neural and flow-based timing. Asynchrony was calculated using the asynchrony index (AI). There was no difference in ABGs regardless of mode and assist level. The differences in breathing pattern, ventilator assistance, and respiratory drive and timing between PSV and NAVA were overall small at the two lower assist levels. At the highest assist level, however, we found greater VT/kg (9.1 +/- 2.2 vs. 7.1 +/- 2 ml/kg, P < 0.001), and lower breathing frequency (12 +/- 6 vs. 18 +/- 8.2, P < 0.001) and peak EAdi (8.6 +/- 10.5 vs. 12.3 +/- 9.0, P < 0.002) in PSV than in NAVA; we found mismatch between neural and flow-based timing in PSV, but not in NAVA. AI exceeded 10% in five (36%) and no (0%) patients with PSV and NAVA, respectively (P < 0.05). Compared to PSV, NAVA averted the risk of over-assistance, avoided patient-ventilator asynchrony, and improved patient-ventilator interaction.

Protective mechanical ventilation, why use it?

PubMed

Seiberlich, Emerson; Santana, Jonas Alves; Chaves, Renata de Andrade; Seiberlich, Raquel Carvalho

2011-01-01

Mechanical ventilation (MV) strategies have been modified over the last decades with a tendency for increasingly lower tidal volumes (VT). However, in patients without acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) the use of high VTs is still very common. Retrospective studies suggest that this practice can be related to mechanical ventilation-associated ALI. The objective of this review is to search for evidence to guide protective MV in patients with healthy lungs and to suggest strategies to properly ventilate lungs with ALI/ARDS. A review based on the main articles that focus on the use of strategies of mechanical ventilation was performed. Consistent studies to determine which would be the best way to ventilate a patient with healthy lungs are lacking. Expert recommendations and current evidence presented in this article indicate that the use of a VT lower than 10 mL.kg(-1), associated with positive end-expiratory pressure (PEEP) ≥ 5 cmH(2)O without exceeding a pressure plateau of 15 to 20 cmH(2)O could minimize alveolar stretching at the end of inspiration and avoid possible inflammation or alveolar collapse. Copyright © 2011 Elsevier Editora Ltda. All rights reserved.

Four-dimensional optical coherence tomography imaging of total liquid ventilated rats

NASA Astrophysics Data System (ADS)

Kirsten, Lars; Schnabel, Christian; Gaertner, Maria; Koch, Edmund

2013-06-01

Optical coherence tomography (OCT) can be utilized for the spatially and temporally resolved visualization of alveolar tissue and its dynamics in rodent models, which allows the investigation of lung dynamics on the microscopic scale of single alveoli. The findings could provide experimental input data for numerical simulations of lung tissue mechanics and could support the development of protective ventilation strategies. Real four-dimensional OCT imaging permits the acquisition of several OCT stacks within one single ventilation cycle. Thus, the entire four-dimensional information is directly obtained. Compared to conventional virtual four-dimensional OCT imaging, where the image acquisition is extended over many ventilation cycles and is triggered on pressure levels, real four-dimensional OCT is less vulnerable against motion artifacts and non-reproducible movement of the lung tissue over subsequent ventilation cycles, which widely reduces image artifacts. However, OCT imaging of alveolar tissue is affected by refraction and total internal reflection at air-tissue interfaces. Thus, only the first alveolar layer beneath the pleura is visible. To circumvent this effect, total liquid ventilation can be carried out to match the refractive indices of lung tissue and the breathing medium, which improves the visibility of the alveolar structure, the image quality and the penetration depth and provides the real structure of the alveolar tissue. In this study, a combination of four-dimensional OCT imaging with total liquid ventilation allowed the visualization of the alveolar structure in rat lung tissue benefiting from the improved depth range beneath the pleura and from the high spatial and temporal resolution.

Results from Carbon Dioxide Washout Testing Using a Suited Manikin Test Apparatus with a Space Suit Ventilation Test Loop

NASA Technical Reports Server (NTRS)

Chullen, Cinda; Conger, Bruce; McMillin, Summer; Vonau, Walt; Kanne, Bryan; Korona, Adam; Swickrath, Mike

2016-01-01

NASA is developing an advanced portable life support system (PLSS) to meet the needs of a new NASA advanced space suit. The PLSS is one of the most critical aspects of the space suit providing the necessary oxygen, ventilation, and thermal protection for an astronaut performing a spacewalk. The ventilation subsystem in the PLSS must provide sufficient carbon dioxide (CO2) removal and ensure that the CO2 is washed away from the oronasal region of the astronaut. CO2 washout is a term used to describe the mechanism by which CO2 levels are controlled within the helmet to limit the concentration of CO2 inhaled by the astronaut. Accumulation of CO2 in the helmet or throughout the ventilation loop could cause the suited astronaut to experience hypercapnia (excessive carbon dioxide in the blood). A suited manikin test apparatus (SMTA) integrated with a space suit ventilation test loop was designed, developed, and assembled at NASA in order to experimentally validate adequate CO2 removal throughout the PLSS ventilation subsystem and to quantify CO2 washout performance under various conditions. The test results from this integrated system will be used to validate analytical models and augment human testing. This paper presents the system integration of the PLSS ventilation test loop with the SMTA including the newly developed regenerative Rapid Cycle Amine component used for CO2 removal and tidal breathing capability to emulate the human. The testing and analytical results of the integrated system are presented along with future work.

Extra corporeal membrane oxygenation to facilitate lung protective ventilation and prevent ventilator-induced lung injury in severe Pneumocystis pneumonia with pneumomediastinum: a case report and short literature review.

PubMed

Ali, Husain Shabbir; Hassan, Ibrahim Fawzy; George, Saibu

2016-04-14

Pulmonary infections caused by Pneumocystis jirovecii in immunocompromised host can be associated with cysts, pneumatoceles and air leaks that can progress to pneumomediastinum and pneumothoraxes. In such cases, it can be challenging to maintain adequate gas exchange by conventional mechanical ventilation and at the same time prevent further ventilator-induced lung injury. We report a young HIV positive male with poorly compliant lungs and pneumomediastinum secondary to severe Pneumocystis infection, rescued with veno-venous extra corporeal membrane oxygenation (V-V ECMO). A 26 year old male with no significant past medical history was admitted with fever, cough and shortness of breath. He initially required non-invasive ventilation for respiratory failure. However, his respiratory function progressively deteriorated due to increasing pulmonary infiltrates and development of pneumomediastinum, eventually requiring endotracheal intubation and invasive ventilation. Despite attempts at optimizing gas exchange by ventilatory maneuvers, patients' pulmonary parameters worsened necessitating rescue ECMO therapy. The introduction of V-V ECMO facilitated the use of ultra-protective lung ventilation and prevented progression of pneumomediastinum, maintaining optimal gas exchange. It allowed time for the antibiotics to show effect and pulmonary parenchyma to heal. Further diagnostic workup revealed Pneumocystis jirovecii as the causative organism for pneumonia and serology confirmed Human Immunodeficiency Virus infection. Patient was successfully treated with appropriate antimicrobials and de-cannulated after six days of ECMO support. ECMO was an effective salvage therapy in HIV positive patient with an otherwise fatal respiratory failure due to Pneumocystis pneumonia and air leak syndrome.

A novel sampling method to detect airborne influenza and other respiratory viruses in mechanically ventilated patients: a feasibility study.

PubMed

Mitchell, Alicia B; Tang, Benjamin; Shojaei, Maryam; Barnes, Lachlan S; Nalos, Marek; Oliver, Brian G; McLean, Anthony S

2018-04-17

Respiratory viruses circulate constantly in the ambient air. The risk of opportunistic infection from these viruses can be increased in mechanically ventilated patients. The present study evaluates the feasibility of detecting airborne respiratory viruses in mechanically ventilated patients using a novel sample collection method involving ventilator filters. We collected inspiratory and expiratory filters from the ventilator circuits of mechanically ventilated patients in an intensive care unit over a 14-month period. To evaluate whether we could detect respiratory viruses collected in these filters, we performed a reverse transcription polymerase chain reaction on the extracted filter membrane with primers specific for rhinovirus, respiratory syncytial virus, influenza virus A and B, parainfluenza virus (type 1, 2 and 3) and human metapneumovirus. For each patient, we also performed a full virology screen (virus particles, antibody titres and virus-induced biomarkers) on respiratory samples (nasopharyngeal swab, tracheal aspirate or bronchoalveolar fluid) and blood samples. Respiratory viruses were detected in the ventilator filters of nearly half the patients in the study cohort (n = 33/70). The most common virus detected was influenza A virus (n = 29). There were more viruses detected in the inspiratory filters (n = 18) than in the expiratory filters (n = 15). A third of the patients with a positive virus detection in the ventilator filters had a hospital laboratory confirmed viral infection. In the remaining cases, the detected viruses were different from viruses already identified in the same patient, suggesting that these additional viruses come from the ambient air or from cross-contamination (staff or visitors). In patients in whom new viruses were detected in the ventilator filters, there was no evidence of clinical signs of an active viral infection. Additionally, the levels of virus-induced biomarker in these patients were not statistically different from those of non-infected patients (p = 0.33). Respiratory viruses were present within the ventilator circuits of patients receiving mechanical ventilation. Although no adverse clinical effect was evident in these patients, further studies are warranted, given the small sample size of the study and the recognition that ventilated patients are potentially susceptible to opportunistic infection from airborne respiratory viruses.

Impact of Extraperitoneal Dioxyde Carbon Insufflation on Respiratory Function in Anesthetized Adults: A Preliminary Study Using Electrical Impedance Tomography and Wash-out/Wash-in Technic

PubMed Central

Bordes, Julien; Mazzeo, Cecilia; Gourtobe, Philippe; Cungi, Pierre Julien; Antonini, Francois; Bourgoin, Stephane; Kaiser, Eric

2015-01-01

Background: Extraperitoneal laparoscopy has become a common technique for many surgical procedures, especially for inguinal hernia surgery. Investigations of physiological changes occurring during extraperitoneal carbon dioxide (CO2) insufflation mostly focused on blood gas changes. To date, the impact of extraperitoneal CO2 insufflation on respiratory mechanics remains unknown, whereas changes in respiratory mechanics have been extensively studied in intraperitoneal insufflation. Objectives: The aim of this study was to investigate the effects of extraperitoneal CO2 insufflation on respiratory mechanics. Patients and Methods: A prospective and observational study was performed on nine patients undergoing laparoscopic inguinal hernia repair. Anesthetic management and intraoperative care were standardized. All patients were mechanically ventilated with a tidal volume of 8 mL/kg using an Engström Carestation ventilator (GE Healthcare). Ventilation distribution was assessed by electrical impedance tomography (EIT). End-expiratory lung volume (EELV) was measured by a nitrogen wash-out/wash-in method. Ventilation distribution, EELV, ventilator pressures and hemodynamic parameters were assessed before extraperitoneal insufflation, and during insufflation with a PEEP of 0 cmH2O, 5 cmH20 and of 10 cmH20. Results: EELV and thoracopulmonary compliance were significantly decreased after extraperitoneal insufflation. Ventilation distribution was significantly higher in ventral lung regions during general anesthesia and was not modified after insufflation. A 10 cmH20 PEEP application resulted in a significant increase in EELV, and a shift of ventilation toward the dorsal lung regions. Conclusions: Extraperitoneal insufflation decreased EELV and thoracopulmonary compliance. Application of a 10 cmH20 PEEP increased EELV and homogenized ventilation distribution. This preliminary clinical study showed that extraperitoneal insufflation worsened respiratory mechanics, which may justify further investigations to evaluate the clinical impact. PMID:25789238

Morphine and outcomes in acute decompensated heart failure: an ADHERE analysis.

PubMed

Peacock, W F; Hollander, J E; Diercks, D B; Lopatin, M; Fonarow, G; Emerman, C L

2008-04-01

Morphine is a long-standing therapy in acute decompensated heart failure (ADHF), despite few supporting data. A study was undertaken to compare the outcomes of patients who did and did not receive morphine for ADHF. The study was a retrospective analysis of the Acute Decompensated Heart Failure National Registry (ADHERE) which enrols hospitalised patients with treatment for, or a primary discharge diagnosis of, ADHF. Patients were stratified into cohorts based on whether or not they received intravenous morphine. ANOVA, Wilcoxon and chi(2) tests were used in univariate analysis, followed by multivariate analysis controlling for parameters previously associated with mortality. Analyses were repeated for ejection fraction subgroups and in patients not on mechanical ventilation. There were 147 362 hospitalisations in ADHERE at December 2004, 20 782 of whom (14.1%) received morphine and 126 580 (85.9%) did not. There were no clinically relevant differences between the groups in the initial age, heart rate, blood pressure, blood urea nitrogen, creatinine, haemoglobin, ejection fraction or atrial fibrillation. A higher prevalence of rest dyspnoea, congestion on chest radiography, rales and raised troponin occurred in the morphine group. Patients on morphine received more inotropes and vasodilators, were more likely to require mechanical ventilation (15.4% vs 2.8%), had a longer median hospitalisation (5.6 vs 4.2 days), more ICU admissions (38.7% vs 14.4%), and had greater mortality (13.0% vs 2.4%) (all p<0.001). Even after risk adjustment and exclusion of ventilated patients, morphine was an independent predictor of mortality (OR 4.84 (95% CI 4.52 to 5.18), p<0.001). Morphine is associated with increased adverse events in ADHF which includes a greater frequency of mechanical ventilation, prolonged hospitalisation, more ICU admissions and higher mortality.

[Effectiveness of implementing the reiki method to reduce the weaning failure. A clinical trial].

PubMed

Saiz-Vinuesa, M D; Rodríguez-Moreno, E; Carrilero-López, C; García Vitoria, J; Garrido-Moya, D; Claramonte-Monedero, R; Piqueras-Carrión, A M

2016-01-01

Admission to intensive care unit (ICU) is a difficult and stressful time for the patient, with the application of different techniques, such as intubation and ventilation support withdrawal or "weaning", which may fail due to anxiety. To determine whether Reiki is useful in reducing weaning failure, as well as reducing the number of days of mechanical ventilation (MV), length of stay in ICU, amount of sedatives, amines, and antipsychotics. Randomized clinical trial. ICU of a Level III University Hospital. ICU patients connected to Mechanical Ventilation for more than 48hours, with a signed informed consent. Patients in a terminal condition or potential organ donors were excluded. 256 patients divided into two groups: intervention group (GI) and placebo (GP). The intervention involves the application of Reiki, and a simulated technique within the placebo group. An analysis was made of the absolute and relative frequencies, with a significance level of P<.05, 95% CI RESULTS: The percentage of failures at weaning was 9% in GI and 9.5% in GP (P=.42). The mean number of days on MV was 8.85 days for GI and 9.66 for the GP (P=.53). The mean dose of sedatives: GI 1078mg and 1491mg GP. The dose of Haloperidol was lower in the GI (5.30mg vs 16.81mg GP) (P=.03, 95% CI; -21.9 to -1.13). Reiki reduces the agitation of patients. A decrease was objectively observed in the number of days of Mechanical Ventilation, length of stay, lower doses of sedatives, and a slight decrease in the weaning failure in the GI. No statistically significant difference was found in the main variable. Copyright © 2015 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

Analysis of the systems of ventilation of residential houses of Ukraine and Estonia

NASA Astrophysics Data System (ADS)

Savchenko, Olena; Zhelykh, Vasyl; Voll, Hendrik

2017-12-01

The most common ventilation system in residential buildings in Ukraine is natural ventilation. In recent years, due to increased tightness of structures, an increase in the content of synthetic finishing materials in them, the quality of microclimate parameters deteriorated. One of the measures to improve the parameters of indoor air in residential buildings is the use of mechanical inflow and exhaust ventilation system. In this article the regulatory documents concerning the design of ventilation systems in Ukraine and Estonia and the requirements for air exchange in residential buildings are considered. It is established that the existing normative documents in Ukraine are analogous to European norms, which allow design the system of ventilation of residential buildings according to European standards. However, the basis for the design of ventilation systems in Ukraine is the national standards, in which mechanical ventilation, unfortunately, is provided only for the design of high-rise buildings. To maintain acceptable microclimate parameters in residential buildings, it is advisable for designers to apply the requirements for designing ventilation systems in accordance with European standards.

Humidification during mechanical ventilation in the adult patient.

PubMed

Al Ashry, Haitham S; Modrykamien, Ariel M

2014-01-01

Humidification of inhaled gases has been standard of care in mechanical ventilation for a long period of time. More than a century ago, a variety of reports described important airway damage by applying dry gases during artificial ventilation. Consequently, respiratory care providers have been utilizing external humidifiers to compensate for the lack of natural humidification mechanisms when the upper airway is bypassed. Particularly, active and passive humidification devices have rapidly evolved. Sophisticated systems composed of reservoirs, wires, heating devices, and other elements have become part of our usual armamentarium in the intensive care unit. Therefore, basic knowledge of the mechanisms of action of each of these devices, as well as their advantages and disadvantages, becomes a necessity for the respiratory care and intensive care practitioner. In this paper, we review current methods of airway humidification during invasive mechanical ventilation of adult patients. We describe a variety of devices and describe the eventual applications according to specific clinical conditions.

30 CFR 57.22201 - Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines). 57.22201 Section 57.22201 Mineral Resources MINE SAFETY AND HEALTH....22201 Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines). All mines shall...

30 CFR 57.22201 - Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines). 57.22201 Section 57.22201 Mineral Resources MINE SAFETY AND HEALTH....22201 Mechanical ventilation (I-A, I-B, I-C, II-A, II-B, III, IV, V-A, and V-B mines). All mines shall...

46 CFR 185.352 - Ventilation of gasoline machinery spaces.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Ventilation of gasoline machinery spaces. 185.352... (UNDER 100 GROSS TONS) OPERATIONS Miscellaneous Operating Requirements § 185.352 Ventilation of gasoline machinery spaces. The mechanical exhaust for the ventilation of a gasoline machinery space, required by...

46 CFR 185.352 - Ventilation of gasoline machinery spaces.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Ventilation of gasoline machinery spaces. 185.352... (UNDER 100 GROSS TONS) OPERATIONS Miscellaneous Operating Requirements § 185.352 Ventilation of gasoline machinery spaces. The mechanical exhaust for the ventilation of a gasoline machinery space, required by...

46 CFR 185.352 - Ventilation of gasoline machinery spaces.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Ventilation of gasoline machinery spaces. 185.352... (UNDER 100 GROSS TONS) OPERATIONS Miscellaneous Operating Requirements § 185.352 Ventilation of gasoline machinery spaces. The mechanical exhaust for the ventilation of a gasoline machinery space, required by...

46 CFR 127.260 - Ventilation for accommodations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation for accommodations. 127.260 Section 127.260... ARRANGEMENTS Particular Construction and Arrangements § 127.260 Ventilation for accommodations. (a) Each... vessel of 100 or more gross tons must be provided with a mechanical ventilation system unless the...

Operating and maintaining your heat recovery ventilator (HRV) -- Revised edition. Home heating and cooling series, Number 8

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Heat recovery ventilators (HRVs) differ from other mechanical ventilation devices by their ability to exchange heat between supply and exhaust air streams, which reduces the cost of heating or cooling fresh air. This booklet discusses the need for mechanical ventilation in conventional and energy-efficient homes, an explains the components of a HRV system, how to operate and maintain the system, and how to solve operating problems. A maintenance chart and schedule and a HRV troubleshooting guide are included.

Development of an Outdoor Temperature-Based Control Algorithm for Residential Mechanical Ventilation Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Less, Brennan; Walker, Iain; Tang, Yihuan

2014-06-01

Smart ventilation systems use controls to ventilate more during those periods that provide either an energy or IAQ advantage (or both) and less during periods that provide a dis advantage. Using detailed building simulations, this study addresses one of the simplest and lowest cost types of smart controllers —outdoor temperature- based control. If the outdoor temperature falls below a certain cut- off, the fan is simply turned off. T he main principle of smart ventilation used in this study is to shift ventilation from time periods with large indoor -outdoor temperature differences, to periods where these differences are smaller, andmore » their energy impacts are expected to be less. Energy and IAQ performance are assessed relative to a base case of a continuously operated ventilation fan sized to comply with ASHRAE 62.2-2013 whole house ventilation requirements. In order to satisfy 62.2-2013, annual pollutant exposure must be equivalent between the temperature controlled and continuous fan cases. This requires ventilation to be greater than 62.2 requirements when the ventilation system operates. This is achieved by increasing the mechanical ventilation system air flow rates.« less