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1

How is mechanical ventilation employed in the intensive care unit? An international utilization review.  

PubMed

A 1-d point-prevalence study was performed with the aim of describing the characteristics of conventional mechanical ventilation in intensive care units ICUs from North America, South America, Spain, and Portugal. The study involved 412 medical-surgical ICUs and 1,638 patients receiving mechanical ventilation at the moment of the study. The main outcome measures were characterization of the indications for initiation of mechanical ventilation, the artificial airways used to deliver mechanical ventilation, the ventilator modes and settings, and the methods of weaning. The median age of the study patients was 61 yr, and the median duration of mechanical ventilation at the time of the study was 7 d. Common indications for the initiation of mechanical ventilation included acute respiratory failure (66%), acute exacerbation of chronic obstructive pulmonary disease (13%), coma (10%), and neuromuscular disorders (10%). Mechanical ventilation was delivered via an endotracheal tube in 75% of patients, a tracheostomy in 24%, and a facial mask in 1%. Ventilator modes consisted of assist/control ventilation in 47% of patients and 46% were ventilated with synchronized intermittent mandatory ventilation, pressure support, or the combination of both. The median tidal volume setting was 9 ml/kg in patients receiving assist/control and the median setting of pressure support was 18 cm H(2)O. Positive end-expiratory pressure was not employed in 31% of patients. Method of weaning varied considerably from country to country, and even within a country several methods were in use. We conclude that the primary indications for mechanical ventilation and the ventilator settings were remarkably similar across countries, but the selection of modes of mechanical ventilation and methods of weaning varied considerably from country to country. PMID:10806138

Esteban, A; Anzueto, A; Alía, I; Gordo, F; Apezteguía, C; Pálizas, F; Cide, D; Goldwaser, R; Soto, L; Bugedo, G; Rodrigo, C; Pimentel, J; Raimondi, G; Tobin, M J

2000-05-01

2

Respiratory care year in review 2013: airway management, noninvasive monitoring, and invasive mechanical ventilation.  

PubMed

Fundamental to respiratory care practice are airway management, noninvasive monitoring, and invasive mechanical ventilation. The purpose of this paper is to review the recent literature related to these topics in a manner that is most likely to have interest to the readers of Respiratory Care. PMID:24713763

Durbin, Charles G; Blanch, Lluís; Fan, Eddy; Hess, Dean R

2014-04-01

3

A student paper: music in critical care setting for clients on mechanical ventilators: a student perspective.  

PubMed

This article written by baccalaureate nursing students briefly discusses the use of music therapy in clients on mechanical ventilation in intensive care units. The article explores the possible benefits of music therapy and its use in other aspects of health care. PMID:23042464

Ho, Van; Chang, Sue; Olivas, Rosa; Almacen, Catherine; Dimanlig, Marbert; Rodriguez, Heather

2012-01-01

4

DNR directives are established early in mechanically ventilated intensive care unit patients  

Microsoft Academic Search

Purpose  Setting treatment goals in the intensive care unit (ICU) often involves resuscitation decisions. Our objective was to study\\u000a the rate of establishing do-not-resuscitate (DNR) directives, determinants, and outcomes of those directives for mechanically\\u000a ventilated patients.\\u000a \\u000a \\u000a \\u000a Methods  In a multicentre observational study, we included consecutive adults with no DNR directives within 24 hr of ICU admission\\u000a who were mechanically ventilated for at

Tasnim Sinuff; Deborah J. Cook; Graeme M. Rocker; Lauren E. Griffith; Stephen D. Walter; Malcolm M. Fisher; Peter M. Dodek; Peter Sjokvist; Ellen McDonald; John C. Marshall; Peter A. Kraus; Mitchell M. Levy; Neil M. Lazar; Gordon H. Guyatt

2004-01-01

5

Home mechanical ventilation and specialised health care in the community: Between a rock and a hard place  

Microsoft Academic Search

Background  Home mechanical ventilation probably represents the most advanced and complicated type of medical treatment provisioned outside\\u000a a hospital setting. The aim of this study was both to explore the challenges experienced by health care professionals in community\\u000a health care services when caring for patients dependent on home mechanical ventilation, continual care and highly advanced\\u000a technology, and their proposed solutions to

Knut Dybwik; Erik W Nielsen; Berit S Brinchmann

2011-01-01

6

Liberation of neurosurgical patients from mechanical ventilation and tracheostomy in neurocritical care.  

PubMed

Neurosurgical patients commonly require mechanical ventilation and monitoring in a neurocritical care unit. There are only few studies that specifically address the process of liberation from mechanical ventilation in this population. Patients who remain ventilator or artificial airway dependent receive a tracheostomy. The appropriate timing for the procedure is not well defined and may be different among an inhomogeneous population of critically ill patients. In this article, we review the general principles of liberation and the current literature as it pertains to neurosurgical patients with primary brain injury. The criteria for "readiness of extubation" include a combination of neurologic assessment, hemodynamic, and respiratory parameters. Future studies are required to better assess indicators for extubation readiness, evaluate the predictors of extubation failure in brain-injured patients, and define the most appropriate timing for a tracheostomy. PMID:22033050

Lazaridis, Christos; DeSantis, Stacia M; McLawhorn, Marc; Krishna, Vibhor

2012-08-01

7

Sedation and memories of patients subjected to mechanical ventilation in an intensive care unit  

PubMed Central

Objective To investigate the relationship between sedation and the memories reported by patients subjected to mechanical ventilation following discharge from the intensive care unit. Methods This prospective, observational, cohort study was conducted with individuals subjected to mechanical ventilation who remained in the intensive care unit for more than 24 hours. Clinical statistics and sedation records were extracted from the participants' clinical records; the data relative to the participants' memories were collected using a specific validated instrument. Assessment was performed three months after discharge from the intensive care unit. Results A total of 128 individuals were assessed, most of whom (84.4%) reported recollections from their stay in the intensive care unit as predominantly a combination of real and illusory events. The participants subjected to sedation (67.2%) at deep levels (Richmond Agitation-Sedation Scale [RASS] -4 and -5) for more than two days and those with psychomotor agitation (33.6%) exhibited greater susceptibility to occurrence of illusory memories (p>0.001). Conclusion The probability of the occurrence of illusory memories was greater among the participants who were subjected to deep sedation. Sedation seems to be an additional factor that contributed to the occurrence of illusory memories in severely ill individuals subjected to mechanical ventilation.

da Costa, Jaquilene Barreto; Marcon, Sonia Silva; de Macedo, Claudia Rejane Lima; Jorge, Amaury Cesar; Duarte, Pericles Almeida Delfino

2014-01-01

8

Conventional mechanical ventilation  

PubMed Central

The provision of mechanical ventilation for the support of infants and children with respiratory failure or insufficiency is one of the most common techniques that are performed in the Pediatric Intensive Care Unit (PICU). Despite its widespread application in the PICUs of the 21st century, before the 1930s, respiratory failure was uniformly fatal due to the lack of equipment and techniques for airway management and ventilatory support. The operating rooms of the 1950s and 1960s provided the arena for the development of the manual skills and the refinement of the equipment needed for airway management, which subsequently led to the more widespread use of endotracheal intubation thereby ushering in the era of positive pressure ventilation. Although there seems to be an ever increasing complexity in the techniques of mechanical ventilation, its successful use in the PICU should be guided by the basic principles of gas exchange and the physiology of respiratory function. With an understanding of these key concepts and the use of basic concepts of mechanical ventilation, this technique can be successfully applied in both the PICU and the operating room. This article reviews the basic physiology of gas exchange, principles of pulmonary physiology, and the concepts of mechanical ventilation to provide an overview of the knowledge required for the provision of conventional mechanical ventilation in various clinical arenas.

Tobias, Joseph D.

2010-01-01

9

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

PubMed

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 (?). 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, ?(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, ?(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 (? = 0.936, SE = 0.08). PMID:21939482

Yücel, ?ebnem Çinar; E?er, Ismet; Güler, Elem Kocaçal; Khorshid, Leyla

2011-10-01

10

Prediction of prolonged mechanical ventilation in patients in the intensive care unit A cohort study  

PubMed Central

Introduction: There are no established guidelines for selecting patients for early tracheostomy. The aim was to determine the factors that could predict the possibility of intubation longer than 7 days in critically ill adult patients. Methods: This is cohort study made at a general intensive care unit. Patients who required at least 48 hours of mechanical ventilation were included. Data on the clinical and physiologic features were collected for every intubated patient on the third day. Uni- and multivariate statistical analyses were conducted to determine the variables associated with extubation. Results: 163 (62%) were male, and the median age was 59±17 years. Almost one-third (36%) of patients required mechanical ventilation longer than 7 days. The variables strongly associated with prolonged mechanical ventilation were: age (HR 0.97 (95% CI 0.96-0.99); diagnosis of surgical emergency in a patient with a medical condition (HR 3.68 (95% CI 1.62-8.35), diagnosis of surgical condition-non emergency (HR 8.17 (95% CI 2.12-31.3); diagnosis of non-surgical-medical condition (HR 5.26 (95% CI 1.85-14.9); APACHE II (HR 0.91 (95% CI 0.85-0.97) and SAPS II score (HR 1.04 (95% CI 1.00-1.09) The area under ROC curve used for prediction was 0.52. 16% of patients were extubated after day 8 of intubation. Conclusions: It was not possible to predict early extubation in critically ill adult patients with invasive mechanical ventilation with common clinical scales used at the ICU. However, the probability of successfully weaning patients from mechanical ventilation without a tracheostomy is low after the eighth day of intubation.

Gomez, Ximena; Vega, Valentin; Dominguez, Luis Carlos; Osorio, Camilo

2013-01-01

11

Mechanical ventilator - infants  

MedlinePLUS

Ventilator - infants; Respirator - infants ... WHY IS A MECHANICAL VENTILATOR USED? A ventilator is used to provide breathing support for ill or immature babies. Sick or premature babies are often ...

12

One-year trajectories of care and resource utilization for recipients of prolonged mechanical ventilation: a cohort study  

PubMed Central

Background Growing numbers of critically ill patients receive prolonged mechanical ventilation. Little is known about their patterns of care as they transition from the acute hospital to post-acute care facilities or the associated resource utilization. Objectives To describe one-year trajectories of care and resource utilization for prolonged mechanical ventilation patients. Design One-year prospective cohort study. Setting 5 ICUs at Duke University Medical Center. Participants 126 prolonged mechanical ventilation patients as well as their 126 surrogates and 54 ICU physicians were enrolled consecutively during one year. Prolonged mechanical ventilation was defined as ventilation for ?4 days with tracheostomy placement or ventilation for ?21 days without tracheostomy. Measurements Patients and surrogates were interviewed in hospital, as well as 3 and 12 months later to determine patient survival, functional status, and facility type and duration of post-discharge care. Physicians were interviewed in-hospital to elicit prognoses. Institutional billing records were used to assign costs for acute care, outpatient care, and inter-facility transportation. We used Medicare claims data to assign costs for post-acute care. Results 103 (82%) hospital survivors experienced 457 separate transitions in post-discharge care location (median 4 [interquartile range 3, 5]), including 68 (67%) patients who were readmitted at least once. Patients spent an average of 74% (CI, 68% to 80%) of all days alive in a hospital, post-acute care facility, or receiving home health care. At one year, 11 (9%) patients 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 (n=4, 21%) or dead (n=56, 44%). Patients experiencing a poor outcome were older, had more comorbidities, and were more frequently discharged to a post-acute care facility than patients with either fair or good outcomes (all p <0.05). Costs per patient were $306,135 (SD $285,467) and total cohort costs totaled $38.1 million, for an estimated $3.5 million per one-year independently functioning survivor. Limitations The results of this single center study may not be applicable to other centers. Conclusions Prolonged mechanical ventilation patients experience multiple transitions of care, resulting in extraordinary 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.

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.

2010-01-01

13

Exploring the competency of the Jordanian intensive care nurses towards endotracheal tube and oral care practices for mechanically ventilated patients: an observational study.  

PubMed

Oral care is an important feature of nursing; it is known that oropharynx is considered the main reservoir of bacterial colonization, so the removal of oral infection is a major duty of all health care providers, particularly nurses. We performed this study to explore endotracheal tube and oral care practices for mechanically ventilated patients of Jordanian intensive care nurses, and to study Jordanian intensive care nurses' practices during, prior to, and post endotracheal tube and oral care for mechanically ventilated patients. Endotracheal tube and oral care of Jordanian intensive care nurses for mechanically ventilated patients was compared with recommendations for endotracheal tube and oral care of American Association of Critical Care Nurses and guidelines of Centers for Disease Control and Prevention. Non- participant structured observational design was conducted using a 24 -item structured observational schedule. The findings show that nurses different in their oral care practices; did not follow American Association of Critical Care Nurses recommendations; and therefore delivered lower-quality oral care than predictable. Important inconsistencies were observed in the nurses' hyperoxygenation, respiratory assessment techniques and infection control practices. PMID:23283054

Batiha, Abdul-Monim Mohammad; Bashaireh, Ibrahim; Albashtawy, Mohammed; Shennaq, Sami

2013-01-01

14

Derivation and validation of a search algorithm to retrospectively identify mechanical ventilation initiation in the intensive care unit  

PubMed Central

Background The development and validation of automated electronic medical record (EMR) search strategies are important for establishing the timing of mechanical ventilation initiation in the intensive care unit (ICU). Thus, we sought to develop and validate an automated EMR search algorithm (strategy) for time zero, the moment of mechanical ventilation initiation in the critically ill patient. Methods The EMR search algorithm was developed on the basis of several mechanical ventilation parameters, with the final parameter being positive end-expiratory pressure (PEEP), and was applied to a comprehensive institutional EMR database. The search algorithm was derived from a secondary retrospective analysis of a subset of 450 patients from a cohort of 2,684 patients admitted to a medical ICU and a surgical ICU from January 1, 2010, through December 31, 2011. It was then validated in an independent subset of 450 patients from the same period. The overall percent of agreement between our search algorithm and a comprehensive manual medical record review in the derivation and validation subsets, using peak inspiratory pressure (PIP) as the reference standard, was compared to assess timing of mechanical ventilation initiation. Results In the derivation subset, the automated electronic search strategy achieved an 87% (??=?0.87) perfect agreement, with 94% agreement to within one minute. In validating this search algorithm, perfect agreement was found in 92% (??=?0.92) of patients, with 99% agreement occurring within one minute. Conclusions The use of an electronic search strategy resulted in highly accurate extraction of mechanical ventilation initiation in the ICU. The search algorithm of mechanical ventilation initiation is highly efficient and reliable and can facilitate both clinical research and patient care management in a timely manner.

2014-01-01

15

Mechanical ventilation in rural ICUs  

PubMed Central

Background: In recent years, rural hospitals have expanded their scope of specialized services, which has led to the development and staffing of rural intensive care units (ICUs). There is little information about the breadth, quality or outcomes of these services. This is particularly true for specialized ICU services such as mechanical ventilation, where little, if any, information exists specifically for rural hospitals. The long-term objectives of this project were to evaluate the quality of medical care provided to mechanically ventilated patients in rural ICUs and to improve patient care through an educational intervention. This paper reports baseline data on patient and hospital characteristics for both rural and rural referral hospitals. Results: Twenty Iowa hospitals were evaluated. Data collected on 224 patients demonstrated a mean age of 70 years and a mean ICU admission Acute Physiology and Chronic Health Evaluation (APACHE) II score of 22, with an associated 36% mortality. Mean length of ICU stay was 10 days, with 7.7 ventilated days. Significant differences were found in both institutional and patient variables between rural referral hospitals and rural hospitals with more limited resources. A subgroup of patients with diagnoses associated with complex ventilation had higher mortality rates than patients without these conditions. Patients who developed nosocomial events had longer mean ventilator and ICU days than patients without nosocomial events. This study also found ICU practices that frequently fell outside the guidelines recommended by a task force describing minimum standards of care for critically ill patients with acute respiratory failure on mechanical ventilation. Conclusions: Despite distinct differences in the available resources between rural referral and rural hospitals, overall mortality rates of ventilated patients are similar. Considering the higher mortality rates observed in patients with complicated medical conditions requiring complex ventilation management, the data may suggest that this subgroup could benefit from treatment at a tertiary center with greater resources and technology.

Fieselmann, John F; Bock, M Jeanne; Hendryx, Michael S; Wakefield, Douglas; Helms, Charles M; Bentler, Suzanne E

1999-01-01

16

Mechanical ventilation in rural ICUs.  

PubMed

BACKGROUND: In recent years, rural hospitals have expanded their scope of specialized services, which has led to the development and staffing of rural intensive care units (ICUs). There is little information about the breadth, quality or outcomes of these services. This is particularly true for specialized ICU services such as mechanical ventilation, where little, if any, information exists specifically for rural hospitals. The long-term objectives of this project were to evaluate the quality of medical care provided to mechanically ventilated patients in rural ICUs and to improve patient care through an educational intervention. This paper reports baseline data on patient and hospital characteristics for both rural and rural referral hospitals. RESULTS: Twenty Iowa hospitals were evaluated. Data collected on 224 patients demonstrated a mean age of 70 years and a mean ICU admission Acute Physiology and Chronic Health Evaluation (APACHE) II score of 22, with an associated 36% mortality. Mean length of ICU stay was 10 days, with 7.7 ventilated days. Significant differences were found in both institutional and patient variables between rural referral hospitals and rural hospitals with more limited resources. A subgroup of patients with diagnoses associated with complex ventilation had higher mortality rates than patients without these conditions. Patients who developed nosocomial events had longer mean ventilator and ICU days than patients without nosocomial events. This study also found ICU practices that frequently fell outside the guidelines recommended by a task force describing minimum standards of care for critically ill patients with acute respiratory failure on mechanical ventilation. CONCLUSIONS: Despite distinct differences in the available resources between rural referral and rural hospitals, overall mortality rates of ventilated patients are similar. Considering the higher mortality rates observed in patients with complicated medical conditions requiring complex ventilation management, the data may suggest that this subgroup could benefit from treatment at a tertiary center with greater resources and technology. PMID:11056720

Fieselmann; Bock; Hendryx; Wakefield; Helms; Bentler

1999-01-01

17

Clinical review: Liberation from mechanical ventilation  

PubMed Central

Mechanical ventilation is the defining event of intensive care unit (ICU) management. Although it is a life saving intervention in patients with acute respiratory failure and other disease entities, a major goal of critical care clinicians should be to liberate patients from mechanical ventilation as early as possible to avoid the multitude of complications and risks associated with prolonged unnecessary mechanical ventilation, including ventilator induced lung injury, ventilator associated pneumonia, increased length of ICU and hospital stay, and increased cost of care delivery. This review highlights the recent developments in assessing and testing for readiness of liberation from mechanical ventilation, the etiology of weaning failure, the value of weaning protocols, and a simple practical approach for liberation from mechanical ventilation.

El-Khatib, Mohamad F; Bou-Khalil, Pierre

2008-01-01

18

Patient-ventilator dyssynchrony during assisted invasive mechanical ventilation.  

PubMed

Patient-ventilator dyssynchrony is common during mechanical ventilation. Dyssynchrony decreases comfort, prolongs mechanical ventilation and intensive care unit stays, and might lead to worse outcome. Dyssynchrony can occur during the triggering of the ventilator, the inspiration period after triggering, the transition from inspiration to expiration, and the expiratory phase. The most common dyssynchronies are delayed triggering, autotriggering, ineffective inspiratory efforts (which can occur at any point in the respiratory cycle), mismatch between the patient's and ventilator's inspiratory times, and double triggering. At present, the detection of dyssynchronies usually depends on healthcare staff observing ventilator waveforms; however, performance is suboptimal and many events go undetected. To date, technological complexity has made it impossible to evaluate patient-ventilator synchrony throughout the course of mechanical ventilation. Studies have shown that a high index of dyssynchrony may increase the duration of mechanical ventilation. Better training, better ventilatory modes, and/or computerized systems that permit better synchronization of patients' demands and ventilator outputs are necessary to improve patient-ventilator synchrony. PMID:23254162

Murias, G; Villagra, A; Blanch, L

2013-04-01

19

[Chronic dependence on mechanical pulmonary ventilation in pediatric care: a necessary debate for Brazil's Unified Health System].  

PubMed

People with prolonged dependence on mechanical ventilation require permanent care and the use of equipment that can result in longer term hospital internment. This can lead to difficulty of access for patients with acute injuries, as well as personal difficulties and stress with reduced quality of life for their families or caregivers due to such longer hospital internment. This critical review of publications dealing with dependence on mechanical ventilation among children and adolescents aimed at making information organized in a systematic manner available in order to support discussion on the subject. It should be borne in mind that changes in epidemiological profile and growing technological access determine needs such as intensive therapy hospital beds and complex home care for chronic patients, which still have limits of supply and regulatory restrictions in the Brazilian public health system. PMID:22031144

Costa, Maria Tereza Fonseca da; Gomes, Maria Auxiliadora; Pinto, Márcia

2011-10-01

20

Cerebrospinal Fluid Penetration and Pharmacokinetics of Vancomycin Administered by Continuous Infusion to Mechanically Ventilated Patients in an Intensive Care Unit  

Microsoft Academic Search

Cerebrospinal fluid (CSF) penetration and the pharmacokinetics of vancomycin were studied after contin- uous infusion (50 to 60 mg\\/kg of body weight\\/day after a loading dose of 15 mg\\/kg) in 13 mechanically ventilated patients hospitalized in an intensive care unit. Seven patients were treated for a sensitive bacterial meningitis and the other six patients, who had a severe concomitant neurologic

JACQUES ALBANESE; MARC LEONE; BERNARD BRUGUEROLLE; MARIE-LAURE AYEM; BRUNO LACARELLE; CLAUDE MARTIN

2000-01-01

21

Factors related to compliance among critical care nurses with performing oral care protocols for mechanically ventilated patients in the intensive care unit.  

PubMed

Oral care is an important component of the ventilator bundle; however, few studies have investigated the factors related to compliance with performing oral care among critical care nurses. In this observational study of 759 oral care opportunities performed by 133 critical care nurses, we found that the overall oral care compliance rate was 83.3%. Multivariate analysis revealed that nurses' age, academic degree, intensive care unit license, and location were independent predictors of performing oral care for patients in the intensive care unit. PMID:24773790

Lin, Hsin-Lan; Yang, Li-Yu; Lai, Chih-Cheng

2014-05-01

22

Diaphragmatic dysfunction in the intensive care unit: caught in the cross-fire between sepsis and mechanical ventilation  

PubMed Central

Accumulating evidence indicates that diaphragmatic weakness is common and frequently severe in mechanically ventilated patients. Supinski and Callahan now report that infection is a major risk factor for diaphragmatic weakness in this patient population. Importantly, they show that patients with the greatest levels of diaphragmatic dysfunction have a much poorer prognosis in terms of more prolonged ventilation as well as higher mortality. Mechanical ventilation itself has also been found to induce diaphragmatic weakness along with cellular changes resembling those found in sepsis. Future studies should be directed at understanding the interaction between sepsis and mechanical ventilation, and to developing therapeutic approaches that target their common cellular pathways implicated in diaphragmatic weakness.

2013-01-01

23

Nontraditional modes of mechanical ventilation: progress or distraction?  

PubMed

As technology continues to develop, a wide range of novel and nontraditional modes of mechanical ventilation have become available for the management of critically ill patients. Proportional assist ventilation, neurally adjusted ventilatory assist and adaptive support ventilation are three novel modes of ventilation, which attempt to optimize patient-ventilator synchrony. Improved interactions between patient and ventilator may be important in improving clinical outcomes. Another important priority for mechanically ventilated patients is lung protection, and nontraditional modes of ventilation that may be implemented to minimize ventilator-associated lung injury include airway pressure release ventilation and high-frequency ventilation. Novel and nontraditional modes of ventilation may represent important tools in the critical care environment; however, continued investigation is needed to determine the overall impact of these various approaches on outcomes for mechanically ventilated patients. PMID:22788942

Turner, David A; Rehder, Kyle J; Cheifetz, Ira M

2012-06-01

24

The mechanical ventilator: past, present, and future.  

PubMed

The use of ventilatory assistance can be traced back to biblical times. However, mechanical ventilators, in the form of negative-pressure ventilation, first appeared in the early 1800s. Positive-pressure devices started to become available around 1900 and today's typical intensive care unit (ICU) ventilator did not begin to be developed until the 1940s. From the original 1940s ventilators until today, 4 distinct generations of ICU ventilators have existed, each with features different from that of the previous generation. All of the advancements in ICU ventilator design over these generations provide the basis for speculation on the future. ICU ventilators of the future will be able to integrate electronically with other bedside technology; they will be able to effectively ventilate all patients in all settings, invasively and noninvasively; ventilator management protocols will be incorporated into the basic operation of the ventilator; organized information will be presented instead of rows of unrelated data; alarm systems will be smart; closed-loop control will be present on most aspects of ventilatory support; and decision support will be available. The key term that will be used to identify these future ventilators will be smart! PMID:21801579

Kacmarek, Robert M

2011-08-01

25

Gastroesophageal reflux in mechanically ventilated pediatric patients and its relation to ventilator-associated pneumonia  

Microsoft Academic Search

ABSTRACT: INTRODUCTION: The objective was to determine the frequency of gastroesophageal reflux (GER) in mechanically ventilated pediatric patients and its role as a risk factor for ventilator-associated pneumonia (VAP), which may be enhanced among those patients. METHODS: The study is a prospective cohort study of mechanically ventilated pediatric patients in the pediatric intensive care unit (PICU) of Ain Shams University

Tarek A Abdel-Gawad; Mostafa A El-Hodhod; Hanan M Ibrahim; Yousef W Michael

2009-01-01

26

Low mechanical ventilation times and reintubation rates associated with a specific weaning protocol in an intensive care unit setting: a retrospective study  

PubMed Central

OBJECTIVES: A number of complications exist with invasive mechanical ventilation and with the use of and withdrawal from prolonged ventilator support. The use of protocols that enable the systematic identification of patients eligible for an interruption in mechanical ventilation can significantly reduce the number of complications. This study describes the application of a weaning protocol and its results. METHODS: Patients who required invasive mechanical ventilation for more than 24 hours were included and assessed daily to identify individuals who were ready to begin the weaning process. RESULTS: We studied 252 patients with a median mechanical ventilation time of 3.7 days (interquartile range of 1 to 23 days), a rapid shallow breathing index value of 48 (median), a maximum inspiratory pressure of 40 cmH2O, and a maximum expiratory pressure of 40 cm H2O (median). Of these 252 patients, 32 (12.7%) had to be reintubated, which represented weaning failure. Noninvasive ventilation was used postextubation in 170 (73%) patients, and 15% of these patients were reintubated, which also represented weaning failure. The mortality rate of the 252 patients studied was 8.73% (22), and there was no significant difference in the age, gender, mechanical ventilation time, and maximum inspiratory pressure between the survivors and nonsurvivors. CONCLUSIONS: The use of a specific weaning protocol resulted in a lower mechanical ventilation time and an acceptable reintubation rate. This protocol can be used as a comparative index in hospitals to improve the weaning system, its monitoring and the informative reporting of patient outcomes and may represent a future tool and source of quality markers for patient care.

de Medeiros Silva, Cilene Saghabi; Timenetsky, Karina T.; Taniguchi, Corinne; Calegaro, Sedila; Azevedo, Carolina Sant'Anna A.; Stus, Ricardo; de Matos, Gustavo Faissol Janot; Eid, Raquel A.C.; Barbas, Carmen Silvia Valente

2012-01-01

27

Invasive fungal infection among hematopoietic stem cell transplantation patients with mechanical ventilation in the intensive care unit  

PubMed Central

Background Invasive fungal infection (IFI) is associated with high morbidity and high mortality in hematopoietic stem cell transplantation (HSCT) patientsThe purpose of this study was to assess the characteristics and outcomes of HSCT patients with IFIs who are undergoing MV at a single institution in Taiwan. Methods We performed an observational retrospective analysis of IFIs in HSCT patients undergoing mechanical ventilation (MV) in an intensive care unit (ICU) from the year 2000 to 2009. The characteristics of these HSCT patients and risk factors related to IFIs were evaluated. The status of discharge, length of ICU stay, date of death and cause of death were also recorded. Results There were 326 HSCT patients at the Linkou Chang-Gung Memorial Hospital (Taipei, Taiwan) during the study period. Sixty of these patients (18%) were transferred to the ICU and placed on mechanical ventilators. A total of 20 of these 60 patients (33%) had IFIs. Multivariate analysis indicated that independent risk factors for IFI were admission to an ICU more than 40 days after HSCT, graft versus host disease (GVHD), and high dose corticosteroid (p < 0.01 for all). The overall ICU mortality rate was 88% (53 of 60 patients), and was not significantly different for patients with IFIs (85%) and those without IFIs (90%, p = 0.676). Conclusion There was a high incidence of IFIs in HSCT patients requiring MV in the ICU in our study cohort. The independent risk factors for IFI are ICU admission more than 40 days after HSCT, GVHD, and use of high-dose corticosteroid.

2012-01-01

28

Impact of enhanced ventilator care bundle checklist on nursing documentation in an intensive care unit.  

PubMed

Ventilator-associated pneumonia is a hospital-acquired infection that may develop in patients 48 hours after mechanical ventilation. The project goal was to determine whether a ventilator-associated pneumonia care bundle checklist embedded into an existing electronic health record would increase completeness of nursing documentation in an intensive care unit setting. With the embedded checklist, there were significant improvements in nursing documentation and a decreased incidence of ventilator-associated pneumonia. PMID:23291742

Malouf-Todaro, Nabia; Barker, James; Jupiter, Daniel; Tipton, Phyllis Hart; Peace, Jane

2013-01-01

29

New Aspects in Mechanical Ventilation  

Microsoft Academic Search

We present a short overview on what is state of the art in mechanical ventilation with emphasis on acute lung injury and acute\\u000a respiratory distress syndrome as well as on some newer trends for weaning of the patients from mechanical ventilation.

Christoph Haberthür; Reto Stocker

2006-01-01

30

Can Selection of Mechanical Ventilation Mode Prevent Increased Intra-Abdominal Pressure in Patients Admitted to the Intensive Care Unit?  

PubMed Central

Background: Increased intra-abdominal pressure (IAP) results in dysfunction of vital organs. The aim of the present study was to evaluate the effect of mechanical ventilation mode on IAP. Methods: In a cohort study, a total of 60 patients aged 20-70 years who were admitted to the ICU and underwent mechanical ventilation were recruited. Mechanical ventilation included one of the three modes: Biphasic positive airway pressure (BIPAP) group, synchronize intermittent mandatory ventilation (SIMV) group, or continuous positive airway pressure (CPAP) group. For each patient, mechanical ventilation mode and its parameters, blood pressure, SpO2, and status of tube feeding and IAP were recorded. Results: Our findings indicate that the study groups were not significantly different in terms of anthropometric characteristics including age (64.5 ± 4, P = 0.1), gender (male/female 31/29, P = 0.63), and body mass index (24 ± 1.2, P = 0.11). Increase IAP was related to the type of respiratory mode with the more increased IAP observed in SIMV mode, followed by BIPAP and CPAP modes (P = 0.01). There were significant correlations between increased IAP and respiratory variables including respiratory rate, pressure support ventilation, and inspiratory pressure (P < 0.05). Tube feeding tolerance through NG-tube was lower in SIMV group, followed by BIPAP and CPAP groups (P < 0.05). Conclusions: There is a significant relationship between respiratory modes and IAP; therefore, it is better to utilize those types of mechanical ventilation like CPAP and BIPAP mode in patients who are prone to Intra-abdominal hypertension.

Rafiei, Mohammad Reza; Aghadavoudi, Omid; Shekarchi, Babak; Sajjadi, Seyed Sajed; Masoudifar, Mehrdad

2013-01-01

31

Volume Assessment in Mechanically Ventilated Critical Care Patients Using Bioimpedance Vectorial Analysis, Brain Natriuretic Peptide, and Central Venous Pressure  

PubMed Central

Purpose. Strategies for volume assessment of critically ill patients are limited, yet early goal-directed therapy improves outcomes. Central venous pressure (CVP), Bioimpedance Vectorial Analysis (BIVA), and brain natriuretic peptide (BNP) are potentially useful tools. We studied the utility of these measures, alone and in combination, to predict changing oxygenation. Methods. Thirty-four mechanically ventilated patients, 26 of whom had data beyond the first study day, were studied. Relationships were assessed between CVP, BIVA, BNP, and oxygenation index (O2I) in a cross-sectional (baseline) and longitudinal fashion using both univariate and multivariable modeling. Results. At baseline, CVP and O2I were positively correlated (R = 0.39; P = .021), while CVP and BIVA were weakly correlated (R = ?0.38; P = .025). The association between slopes of variables over time was negligible, with the exception of BNP, whose slope was correlated with O2I (R = 0.40; P = .044). Comparing tertiles of CVP, BIVA, and BNP slopes with the slope of O2I revealed only modest agreement between BNP and O2I (kappa = 0.25; P = .067). In a regression model, only BNP was significantly associated with O2I; however, this was strengthened by including CVP in the model. Conclusions. BNP seems to be a valuable noninvasive measure of volume status in critical care and should be assessed in a prospective manner.

House, Andrew A.; Haapio, Mikko; Lentini, Paolo; Bobek, Ilona; de Cal, Massimo; Cruz, Dinna N.; Virzi, Grazia M.; Carraro, Rizzieri; Gallo, Giampiero; Piccinni, Pasquale; Ronco, Claudio

2011-01-01

32

Emerging modes of ventilation in the intensive care unit.  

PubMed

Potentially harmful effects of positive pressure mechanical ventilation have been recognized since its inception in the 1950s. Since then, the risk factors for and mechanisms of ventilator-induced lung injury (VILI) have been further characterized. Publication of the ARDSnet tidal volume trial in 2000 demonstrated that a ventilator strategy limiting tidal volumes and plateau pressure in patients with acute respiratory distress syndrome was associated with a 22% reduction in mortality. Since then, a variety of ventilator modes have emerged seeking to improve gas exchange, reduce injurious effects of ventilation, and improve weaning from the ventilator. We review here emerging ventilator modes in the intensive care unit (ICU). Airway pressure release ventilation seeks to optimize alveolar recruitment and maintain spontaneous ventilatory effort. It is associated with improved indices of respiratory and cardiovascular physiology, but data to support outcome benefit are lacking. High-frequency oscillatory ventilation is associated with improvements in gas exchange, but outcome data are conflicting. Extracorporeal modes of ventilation continue to evolve, and extra-corporeal CO(2) removal is a technique that could be used in non-specialist ICUs. Proportional-assist ventilation and neutrally adjusted ventilator assist are modes that vary level of assistance with patient ventilatory effort. They result in greater patient-ventilator synchrony, but at present there is no evidence of a reduction in the duration of mechanical ventilation or outcome benefit. Although the use of many of these modes is likely to increase in intensive care units, further evidence of a beneficial effect is desirable before they are recommended. PMID:21613281

Stewart, N I; Jagelman, T A J; Webster, N R

2011-07-01

33

Genetic Relationships between Respiratory Pathogens Isolated from Dental Plaque and Bronchoalveolar Lavage Fluid from Patients in the Intensive Care Unit Undergoing Mechanical Ventilation  

PubMed Central

Background Ventilator-associated pneumonia (VAP) is a leading cause of morbidity and mortality in patients hospitalized in intensive care units. Recent studies suggest that dental plaque biofilms serve as a reservoir for respiratory pathogens. The goal of this study was to determine the genetic relationship between strains of respiratory pathogens first isolated from the oral cavity and later isolated from bronchoalveolar lavage fluid from the same patient undergoing mechanical ventilation with suspected VAP. Methods Plaque and tracheal secretion samples were obtained on the day of hospital admission and every other day thereafter until discharge from the intensive care unit from 100 patients who underwent mechanical ventilation. Bronchoalveolar lavage was performed for 30 patients with suspected VAP. Pulse-field gel electrophoresis and multilocus sequence typing were used to determine the genetic relatedness of strains obtained from oral, tracheal, and bronchoalveolar lavage samples. Results Isolates of Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter species, and enteric species recovered from plaque from most patients were indistinguishable from isolates recovered from bronchoalveolar lavage fluid (i.e., had >95% similarity of pulse-field gel electrophoresis patterns). Nearly one-half of the Pseudomonas strains showed identical genetic profiles between patients, which suggested a common environmental source of infection. Conclusions Respiratory pathogens isolated from the lung are often genetically indistinguishable from strains of the same species isolated from the oral cavity in patients who receive mechanical ventilation who are admitted to the hospital from the community. Thus, dental plaque serves as an important reservoir for respiratory pathogens in patients who undergo mechanical ventilation. Trial registration ClinicalTrials.gov identifier: NCT00123123

Heo, Seok-Mo; Haase, Elaine M.; Lesse, Alan J.; Gill, Steven R.; Scannapieco, Frank A.

2013-01-01

34

Benefits and risks of manual hyperinflation in intubated and mechanically ventilated intensive care unit patients: a systematic review  

PubMed Central

Introduction Manual hyperinflation (MH), a frequently applied maneuver in critically ill intubated and mechanically ventilated patients, is suggested to mimic a cough so that airway secretions are mobilized toward the larger airways, where they can easily be removed. As such, MH could prevent plugging of the airways. Methods We performed a search in the databases of Medline, Embase, and the Cochrane Library from January 1990 to April 2012. We systematically reviewed the literature on evidence for postulated benefits and risks of MH in critically ill intubated and mechanically ventilated patients. Results The search identified 50 articles, of which 19 were considered relevant. We included 13 interventional studies and six observational studies. The number of studies evaluating physiological effects of MH is limited. Trials differed too much to permit meta-analysis. It is uncertain whether MH was applied similarly in the retrieved studies. Finally, most studies are underpowered to show clinical benefit of MH. Use of MH is associated with short-term improvements in lung compliance, oxygenation, and secretion clearance, without changes in outcomes. MH has been reported to be associated with short-term and probably clinically insignificant side effects, including decreases in cardiac output, alterations of heart rates, and increased central venous pressures. Conclusions Studies have failed to show that MH benefits critically ill intubated and mechanically ventilated patients. MH is infrequently associated with short-term side effects.

2012-01-01

35

Anxiety and Agitation in Mechanically Ventilated Patients  

PubMed Central

During an ethnography conducted in an intensive care unit (ICU), we found that anxiety and agitation occurred frequently, and were important considerations in the care of 30 patients weaning from prolonged mechanical ventilation. We conducted a secondary analysis to (a) describe characteristics of anxiety and agitation experienced by mechanically ventilated patients; (b) explore how clinicians recognize and interpret anxiety and agitation and (c) describe strategies and interventions used to manage anxiety and agitation with mechanically ventilated patients. We constructed the Anxiety-Agitation in Mechanical Ventilation Model to illustrate the multidimensional features of symptom recognition and management. Patients’ ability to interact with the environment served as a basis for identification and management of anxiety or agitation. Clinicians’ attributions about anxiety or agitation and “knowing the patient” contributed to their assessment of patient responses. Clinicians chose strategies to overcome either the stimulus or patient’s appraisal of risk of the stimulus. This article contributes to the body of knowledge about symptom recognition and management in the ICU by providing a comprehensive model to guide future research and practice.

Tate, Judith Ann; Dabbs, Annette Devito; Hoffman, Leslie; Milbrandt, Eric; Happ, Mary Beth

2013-01-01

36

Effectiveness of Medical Resident Education in Mechanical Ventilation  

Microsoft Academic Search

Specific methods of mechanical ventilation management reduce 3), and reduce costs and ICU complications (3) for the nearly mortality and lower health care costs. However, in the face of a 1.5 million U.S. patients who require mechanical ventilation predicted deficit of intensivists, it is unclear whether residency pro- each year (4). Critically ill patients with acute respiratory grams are training

Christopher E. Cox; Shannon S. Carson; E. Wesley Ely; Joseph A. Govert; Joanne M. Garrett; Roy G. Brower; David G. Morris; Edward Abraham; Vincent Donnabella; Antoinette Spevetz; Jesse B. Hall

2003-01-01

37

Novel modes of mechanical ventilation.  

PubMed

The overarching goal of positive pressure mechanical ventilation is to provide adequate gas exchange support while not causing harm. Indeed, positive pressure mechanical ventilators are only support technologies, not therapeutic technologies. As such they cannot be expected to "cure" disease; they can only "buy time" for other therapies (including the patient's own defenses) to work.Conventional approaches to positive pressure ventilation involve applying ventilatory patterns mimicking normal ones through either masks or artificial airways. This is usually done with modes of support incorporating assist/control breath-triggering mechanisms, gas delivery patterns governed by either a set flow or pressure, and breath cycling based on either a set volume, a set inspiratory time, or a set flow. Often this support includes positive end-expiratory pressure and supplemental oxygen. In recent decades several novel or unconventional approaches to providing mechanical ventilatory support have been introduced. For these to be considered of value, however, it would seem reasonable that they address important clinical challenges and be shown to improve important clinical outcomes (e.g., mortality, duration of ventilation, sedation needs, complications). This article focuses on challenges facing clinicians in providing mechanical ventilatory support and assesses several novel approaches introduced over the last 2 decades in the context of these challenges. PMID:23934718

Al-Hegelan, Mashael; MacIntyre, Neil R

2013-08-01

38

An Economic Evaluation of Prolonged Mechanical Ventilation  

PubMed Central

Objective Patients who receive prolonged mechanical ventilation (PMV) have high resource utilization and relatively poor outcomes, especially the elderly, and are increasing in number. The economic implications of PMV provision however are uncertain and would be helpful to providers and policymakers. Therefore, we aimed to determine the lifetime societal value of PMV. Design and Patients Adopting the perspective of a healthcare payor, we developed a Markov model to determine the cost-effectiveness of providing mechanical ventilation for at least 21 days to a 65 year-old critically ill base-case patient compared to the provision of comfort care resulting in withdrawal of ventilation. Input data were derived from the medical literature, Medicare, and a recent large cohort study of ventilated patients. Measurements and Main Results We determined lifetime costs and survival, quality-adjusted life expectancy, and cost-effectiveness as reflected by costs per quality-adjusted life year gained ($ per QALY). Providing PMV to the base-case patient cost $55,460 per life-year gained and $82,411 per QALY gained compared to withdrawal of ventilation. Cost-effectiveness ratios were most sensitive to variation in age, hospital costs, and probability of readmission, though less sensitive to post-acute care facility costs. Specifically, incremental costs per QALY gained by PMV provision exceeded $100,000 with age ?68 and when predicted one-year mortality was >50%. Conclusions The cost-effectiveness of PMV provision varies dramatically based on age and likelihood of poor short- and long-term outcomes. Identifying patients likely to have unfavorable outcomes, lowering intensity of care for appropriate patients, and reducing costly readmissions should be future priorities in improving the value of PMV.

Cox, Christopher E.; Carson, Shannon S.; Govert, Joseph A.; Chelluri, Lakshmipathi; Sanders, Gillian D.

2009-01-01

39

Not-So-Trivial Pursuit: Mechanical Ventilation Risk Reduction  

PubMed Central

As many as half of critically ill patients require mechanical ventilation. In this article, a program of research focused on reduction of risk associated with mechanical ventilation is reviewed. Airway management practices can have profound effects on outcomes in these patients. How patients are suctioned, types of processes used, effects of suctioning in patients with lung injury, and open versus closed suctioning systems all have been examined to determine best practices. Pneumonia is a common complication of mechanical ventilation (ventilator-associated pneumonia), and use of higher backrest elevations reduces risk of pneumonia, although compliance with such recommendations varies. The studies reviewed here describe backrest elevation practices, factors that affect backrest elevation, and the effect of backrest elevation on ventilator-associated pneumonia. Oral care strategies also have been investigated to determine their effect on ventilator-associated pneumonia. Oral care practices are reported to hold a low care priority, vary widely across care providers, and differ in intubated versus nonintubated patients. However, in several studies, oral applications of chlorhexidine have reduced the occurrence of ventilator-associated pneumonia. Although ventilator patients require sedation, sedation is associated with significant risks. The overall goals of sedation are to provide physiological stability, to maintain ventilator synchrony, and to ensure patients' comfort–although methods to evaluate achievement of these goals are limited. Reducing risks associated with mechanical ventilation in critically ill patients is a complex and interdisciplinary process. Our understanding of the risks associated with mechanical ventilation is constantly changing, but care of these patients must be based on the best evidence.

Grap, Mary Jo

2013-01-01

40

Weaning from mechanical ventilation  

Microsoft Academic Search

Weaning covers the entire process of liberating the patient from mechanical support and from the endotracheal tube. Many controversial questions remain concerning the best methods for conducting this process. An International Consensus Conference was held in April 2005 to provide recommendations regarding the management of this process. An 11-member international jury answered five pre-defined questions. 1) What is known about

J. M. Boles; J. Bion; A. Connors; M. Herridge; B. Marsh; C. Melote; R. Pearl; H. Silverman; M. Stanchina; A. Vieillard-Baron; T. Welte

2007-01-01

41

Amyotrophic Lateral Sclerosis Patients' Perspectives on Use of Mechanical Ventilation.  

ERIC Educational Resources Information Center

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…

Young, Jenny M.; And Others

1994-01-01

42

Ventilator-associated pneumonia bundle: reconstruction for best care.  

PubMed

The ventilator-associated pneumonia (VAP) bundle is a focus of many health care institutions. Many hospitals are conducting process-improvement projects in an attempt to improve VAP rates by implementing the bundle. However, this bundle is controversial in the literature, because the evidence supporting the VAP interventions is weak. In addition, definitions used for surveillance are interpreted differently than definitions used for clinical diagnosis. The variance in definitions has led to lower reported VAP rates, which may not be accurate. Because of the variance in definitions, the Centers for Disease Control and Prevention developed a ventilator-associated event algorithm. Health care institutions are under pressure to reduce the VAP infection rate, but correctly identifying VAP can be very challenging. This article reviews the current evidence related to VAP and provides insight into implementing a suggested revision of the care of patients being treated with mechanical ventilation. PMID:24752029

Munro, Nancy; Ruggiero, Margaret

2014-01-01

43

Pressure modes of invasive mechanical ventilation.  

PubMed

Pressure modes of invasive mechanical ventilation generate a tidal breath by delivering pressure over time. Pressure control ventilation (PC) is the prototypical pressure mode and is patient- or time-triggered, pressure-limited, and time-cycled. Other pressure modes include pressure support ventilation (PSV), pressure-regulated volume control (PRVC, also known as volume control plus [VC+]), airway pressure release ventilation (APRV), and biphasic ventilation (also known as BiLevel). Despite their complexity, modern ventilators respond to patient effort and respiratory system mechanics in a fairly predictable fashion. No single mode has consistently demonstrated superiority in clinical trials; however, empiric management with a pressure mode may achieve the goals of patient-ventilator synchrony, effective respiratory system support, adequate gas exchange, and limited ventilator-induced lung injury. PMID:21941160

Singer, Benjamin D; Corbridge, Thomas C

2011-10-01

44

A comparison of gradual sedation levels using the Comfort-B scale and bispectral index in children on mechanical ventilation in the pediatric intensive care unit  

PubMed Central

Objective Compare the scores resulting from the Comfort-B scale with the bispectral index in children in an intensive care unit. Methods Eleven children between the ages of 1 month and 16 years requiring mechanical ventilation and sedation were simultaneously classified based on the bispectral index and the Comfort-B scale. Their behavior was recorded using digital photography, and the record was later evaluated by three independent evaluators. Agreement tests (Bland-Altman and Kappa) were then performed. The correlation between the two methods (Pearson correlation) was tested. Results In total, 35 observations were performed on 11 patients. Based on the Kappa coefficient, the agreement among evaluators ranged from 0.56 to 0.75 (p<0.001). There was a positive and consistent association between the bispectral index and the Comfort-B scale [r=0.424 (p=0.011) to r=0.498 (p=0.002)]. Conclusion Due to the strong correlation between the independent evaluators and the consistent correlation between the two methods, the results suggest that the Comfort-B scale is reproducible and useful in classifying the level of sedation in children requiring mechanical ventilation.

Silva, Claudia da Costa; Alves, Marta Maria Osorio; El Halal, Michel Georges dos Santos; Pinheiro, Sabrina dos Santos; Carvalho, Paulo Roberto Antonacci

2013-01-01

45

[Mechanical ventilation in acute respiratory distress syndrome].  

PubMed

The goal of mechanically ventilating patients with acute respiratory distress syndrome (ARDS) is to ensure adequate oxygenation and minimal ventilator-associated lung injury. Non-invasive ventilation should be cautiously used in patients with ARDS. Protective ARDS mechanical ventilation strategies with low tidal volumes can reduce mortality. Driving pressure is the most reasonable parameter to optimize tidal volume. Available evidence does not support the routine use of higher positive end expiratory pressure (PEEP) in patients with ARDS. The optimal level of PEEP may be titrated by the inflection point obtained from static pressure-volume curve. Promising therapies include prone position ventilation, high frequency oscillatory ventilation and extracorporeal membrane oxygenation as salvage treatment. While mechanically ventilating, it is also important for ARDS patients to maintain spontaneous breathing via assisted ventilation mode such as bilevel positive airway pressure, pressure support ventilation and neurally adjusted ventilation assist. Exogenous surfactant, inhaled nitric oxide, bronchodilators, airway pressure release ventilation and partial liquid ventilation are not recommended therapies. PMID:23791070

Wang, Ya-Mei; Tao, Yu-Hong

2013-06-01

46

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

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.

2011-01-01

47

Mechanical Ventilation and the Kidney  

PubMed Central

Acute lung injury (ALI) and acute kidney injury (AKI) are complications often encountered in the setting of critical illness. Both forms of end-organ injury commonly occur in similar settings of systemic inflammatory response syndrome, shock, and evolving multiple organ dysfunction. Recent elucidation of the pathobiology of critical illness has led to a more basic mechanistic understanding of the complex interplay between injured organs in patients with multiple organ dysfunction syndrome; this has been aptly called ‘the slippery slope of critical illness’ [Kidney Int Suppl 1998;66:S25–S33]. Distant organ effects of apparently isolated injuries to the lungs, gut, and kidneys have all been discovered in recent years. In this article, we will review the harmful bidirectional interaction between ALI and AKI, which appears to be a common clinical syndrome with routine clinical implications. We will review the current understanding of lung-kidney interactions from both perspectives, including the renal effects of ALI and mechanical ventilation, and the pulmonary sequelae of AKI. In this review of the emerging evidence of deleterious bidirectional organ cross talk between lung and kidney, we will focus on the role of ventilator-induced kidney injury in the pathogenesis of AKI in patients with ALI.

Koyner, Jay L.; Murray, Patrick T.

2010-01-01

48

The basis and basics of mechanical ventilation.  

PubMed

The development of mechanical ventilators and the procedures for their application began with the simple foot pump developed by Fell O'Dwyer in 1888. Ventilators have progressed through three generations, beginning with intermittent positive pressure breathing units such as the Bird and Bennett device in the 1960s. These were followed by second-generation units--represented by the Bennett MA-2 ventilator--in the 1970s, and the third-generation microprocessor-controlled units of today. During this evolutionary process clinicians recognized Types I and II respiratory failure as being indicators for mechanical ventilatory support. More recently investigators have expanded, clarified, and clinically applied the physiology of the work of breathing (described by Julius Comroe and other pioneers) to muscle fatigue, requiring ventilatory support. A ventilator classification system can help the clinician understand how ventilators function and under what conditions they may fail to operate as desired. Pressure-support ventilation is an example of how industry has responded to a clinical need--that is, to unload the work of breathing. All positive pressure ventilators generate tidal volumes by using power sources such as medical gas cylinders, air compressors, electrically driven turbines, or piston driven motors. Positive end-expiratory pressures, synchronized intermittent mandatory ventilation, pressure support ventilation, pressure release ventilation, and mandatory minute ventilation, are examples of the special functions available on modern ventilators. Modern third-generation ventilators use microprocessors to control operational functions and monitors. Because these units have incorporated the experience learned from earlier ventilators, it is imperative that clinicians understand basic ventilator operation and application in order to most effectively prescribe and assess their use. PMID:2036934

Bone, R C; Eubanks, D H

1991-06-01

49

Mechanical Ventilation Drives Inflammation in Severe Viral Bronchiolitis  

PubMed Central

Introduction Respiratory insufficiency due to severe respiratory syncytial virus (RSV) infection is the most frequent cause of paediatric intensive care unit admission in infants during the winter season. Previous studies have shown increased levels of inflammatory mediators in airways of mechanically ventilated children compared to spontaneous breathing children with viral bronchiolitis. In this prospective observational multi-center study we aimed to investigate whether this increase was related to disease severity or caused by mechanical ventilation. Materials and Methods Nasopharyngeal aspirates were collected <1 hour before intubation and 24 hours later in RSV bronchiolitis patients with respiratory failure (n?=?18) and non-ventilated RSV bronchiolitis controls (n?=?18). Concentrations of the following cytokines were measured: interleukin (IL)-1?, IL-1?, IL-6, monocyte chemotactic protein (MCP)-1 and macrophage inflammatory protein (MIP)-1?. Results Baseline cytokine levels were comparable between ventilated and non-ventilated infants. After 24 hours of mechanical ventilation mean cytokine levels, except for MIP-1?, were elevated compared to non-ventilated infected controls: IL-1? (159 versus 4 pg/ml, p<0.01), IL-1? (1068 versus 99 pg/ml, p<0.01), IL-6 (2343 versus 958 pg/ml, p<0.05) and MCP-1 (174 versus 26 pg/ml, p<0.05). Conclusions Using pre- and post-intubation observations, this study suggests that endotracheal intubation and subsequent mechanical ventilation cause a robust pulmonary inflammation in infants with RSV bronchiolitis.

Hennus, Marije P.; van Vught, Adrianus J.; Brabander, Mark; Brus, Frank; Jansen, Nicolaas J.; Bont, Louis J.

2013-01-01

50

Influence of body mass index on outcome of the mechanically ventilated patients  

Microsoft Academic Search

BackgroundThere are limited data on the impact of body mass index on outcomes in mechanically ventilated patients.MethodsSecondary analysis of a cohort including 4698 patients mechanically ventilated. Patients were screened daily for management of mechanical ventilation, complications (acute respiratory distress syndrome, sepsis, ventilator associated pneumonia, barotrauma), organ failure (cardiovascular, respiratory, renal, hepatic, haematological) and mortality in the intensive care unit. To

A Anzueto; F Frutos-Vivar; A Esteban; N Bensalami; D Marks; K Raymondos; C Apezteguía; Y Arabi; J Hurtado; M González; V Tomicic; F Abroug; J Elizalde; N Cakar; P Pelosi; N D Ferguson

2010-01-01

51

Spontaneous breathing during mechanical ventilation in ARDS  

Microsoft Academic Search

The objective of mechanical ventilation used in the management of Acute Respiratory Distress Syn- drome (ARDS) is to ensure adequate tissue oxygen- ation and alveolar ventilation while limiting the pa- tients' work of breathing and preventing further dam- age to the lungs. Although the \\

Ross Freebairn; Keith Hickling

2005-01-01

52

Nurse-led weaning from mechanical ventilation: where’s the evidence?  

Microsoft Academic Search

Several authors have suggested clinical protocols as a means of shortening ventilation time and the important role of the nurse in reducing ventilation time has also been highlighted. Despite the many references in the literature to reducing weaning times using clinical protocols, it is not clear whether nurse-led weaning strategies hasten weaning from mechanical ventilation compared with physician-led care. Objective:

Ann M. Price

2001-01-01

53

Negative pressure ventilation versus conventional mechanical ventilation in the treatment of acute respiratory failure in COPD patients  

Microsoft Academic Search

This case-control study was aimed to evaluate the effectiveness of nega- tive pressure ventilation (NPV) versus conventional mechanical ventilation (CMV) for the treatment of acute respiratory failure (ARF) in patients with chronic obstructive pulmonary disease (COPD) admitted to a respiratory intermediate intensive care unit (RIICU) and four general intensive care units (ICU). Twenty-six COPD patients in ARF admitted in 1994-95

A. Corrado; M. Gorini; R. Ginanni; C. Pelagatti; G. Villella; U. Buoncristiano; F. Guidi; E. Pagni; A. Peris; E. De Paola

1998-01-01

54

Evolution of mortality over time in patients receiving mechanical ventilation.  

PubMed

Rationale: Baseline characteristics and management have changed over time in patients requiring mechanical ventilation; however, the impact of these changes on patient outcomes is unclear. Objectives: To estimate whether mortality in mechanically ventilated patients has changed over time. Methods: Prospective cohort studies conducted in 1998, 2004, and 2010, including patients receiving mechanical ventilation for more than 12 hours in a 1-month period, from 927 units in 40 countries. To examine effects over time on mortality in intensive care units, we performed generalized estimating equation models. Measurements and Main Results: We included 18,302 patients. The reasons for initiating mechanical ventilation varied significantly among cohorts. Ventilatory management changed over time (P < 0.001), with increased use of noninvasive positive-pressure ventilation (5% in 1998 to 14% in 2010), a decrease in tidal volume (mean 8.8 ml/kg actual body weight [SD = 2.1] in 1998 to 6.9 ml/kg [SD = 1.9] in 2010), and an increase in applied positive end-expiratory pressure (mean 4.2 cm H2O [SD = 3.8] in 1998 to 7.0 cm of H2O [SD = 3.0] in 2010). Crude mortality in the intensive care unit decreased in 2010 compared with 1998 (28 versus 31%; odds ratio, 0.87; 95% confidence interval, 0.80-0.94), despite a similar complication rate. Hospital mortality decreased similarly. After adjusting for baseline and management variables, this difference remained significant (odds ratio, 0.78; 95% confidence interval, 0.67-0.92). Conclusions: Patient characteristics and ventilation practices have changed over time, and outcomes of mechanically ventilated patients have improved. Clinical trials registered with www.clinicaltrials.gov (NCT01093482). PMID:23631814

Esteban, Andrés; Frutos-Vivar, Fernando; Muriel, Alfonso; Ferguson, Niall D; Peñuelas, Oscar; Abraira, Victor; Raymondos, Konstantinos; Rios, Fernando; Nin, Nicolas; Apezteguía, Carlos; Violi, Damian A; Thille, Arnaud W; Brochard, Laurent; González, Marco; Villagomez, Asisclo J; Hurtado, Javier; Davies, Andrew R; Du, Bin; Maggiore, Salvatore M; Pelosi, Paolo; Soto, Luis; Tomicic, Vinko; D'Empaire, Gabriel; Matamis, Dimitrios; Abroug, Fekri; Moreno, Rui P; Soares, Marco Antonio; Arabi, Yaseen; Sandi, Freddy; Jibaja, Manuel; Amin, Pravin; Koh, Younsuck; Kuiper, Michael A; Bülow, Hans-Henrik; Zeggwagh, Amine Ali; Anzueto, Antonio

2013-07-15

55

Optimization of mechanical ventilator settings for pulmonary disease states.  

PubMed

The selection of mechanical ventilator settings that ensure adequate oxygenation and carbon dioxide clearance while minimizing the risk of ventilator-associated lung injury (VALI) is a significant challenge for intensive-care clinicians. Current guidelines are largely based on previous experience combined with recommendations from a limited number of in vivo studies whose data are typically more applicable to populations than to individuals suffering from particular diseases of the lung. By combining validated computational models of pulmonary pathophysiology with global optimization algorithms, we generate in silico experiments to examine current practice and uncover optimal combinations of ventilator settings for individual patient and disease states. Formulating the problem as a multiobjective, multivariable constrained optimization problem, we compute settings of tidal volume, ventilation rate, inspiratory/expiratory ratio, positive end-expiratory pressure and inspired fraction of oxygen that optimally manage the tradeoffs between ensuring adequate oxygenation and carbon dioxide clearance and minimizing the risk of VALI for different pulmonary disease scenarios. PMID:23322759

Das, Anup; Menon, Prathyush P; Hardman, Jonathan G; Bates, Declan G

2013-06-01

56

Brazilian recommendations of mechanical ventilation 2013. Part I  

PubMed Central

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.

Barbas, Carmen Silvia Valente; Isola, Alexandre Marini; Farias, Augusto Manoel de Carvalho; Cavalcanti, Alexandre Biasi; Gama, Ana Maria Casati; Duarte, Antonio Carlos Magalhaes; 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, Debora 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, Joao Claudio; Valiatti, Jorge Luis dos Santos; Teles, Jose Mario Meira; Victorino, Josue Almeida; Ferreira, Juliana Carvalho; Prodomo, Luciana Passuello do Vale; Hajjar, Ludhmila Abrahao; Martins, Luiz Claudio; Malbouisson, Luiz Marcelo Sa; Vargas, Mara Ambrosina de Oliveira; Reis, Marco Antonio Soares; Amato, Marcelo Brito Passos; Holanda, Marcelo Alcantara; Park, Marcelo; Jacomelli, Marcia; Tavares, Marcos; Damasceno, Marta Cristina Paulette; Assuncao, Murillo Santucci Cesar; Damasceno, Moyzes Pinto Coelho Duarte; Youssef, Nazah Cherif Mohamad; Teixeira, Paulo Jose Zimmermann; Caruso, Pedro; Duarte, Pericles 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, Veronica Moreira

2014-01-01

57

Iatrogenic pneumothorax related to mechanical ventilation  

PubMed Central

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.

Hsu, Chien-Wei; Sun, Shu-Fen

2014-01-01

58

Iatrogenic pneumothorax related to mechanical ventilation.  

PubMed

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

Hsu, Chien-Wei; Sun, Shu-Fen

2014-02-01

59

42 CFR 440.185 - Respiratory care for ventilator-dependent individuals.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Respiratory care for ventilator-dependent individuals. 440.185... § 440.185 Respiratory care for ventilator-dependent individuals. (a) âRespiratory care for ventilator-dependent individualsâ...

2013-10-01

60

Clinical review: Mechanical ventilation in severe asthma  

PubMed Central

Respiratory failure from severe asthma is a potentially reversible, life-threatening condition. Poor outcome in this setting is frequently a result of the development of gas-trapping. This condition can arise in any mechanically ventilated patient, but those with severe airflow limitation have a predisposition. It is important that clinicians managing these types of patients understand that the use of mechanical ventilation can lead to or worsen gas-trapping. In this review we discuss the development of this complication during mechanical ventilation, techniques to measure it and strategies to limit its severity. We hope that by understanding such concepts clinicians will be able to reduce further the poor outcomes occasionally related to severe asthma.

Stather, David R; Stewart, Thomas E

2005-01-01

61

Interfaces and humidification for noninvasive mechanical ventilation.  

PubMed

During noninvasive ventilation (NIV) for acute respiratory failure, the patient's comfort may be less important than the efficacy of the treatment. However, mask fit and care are needed to prevent skin damage and air leaks that can dramatically reduce patient tolerance and the efficacy of NIV. Choice of interface is a major determinant of NIV success or failure. The number and types of NIV interface has increased and new types are in development. Oronasal mask is the most commonly used interface in acute respiratory failure, followed by nasal mask, helmet, and mouthpiece. There is no perfect NIV interface, and interface choice requires careful evaluation of the patient's characteristics, ventilation modes, and type of acute respiratory failure. Every effort should be made to minimize air leaks, maximize patient comfort, and optimize patient-ventilator interaction. Technological issues to consider when choosing the NIV interface include dead space (dynamic, apparatus, and physiologic), the site and type of exhalation port, and the functioning of the ventilator algorithm with different masks. Heating and humidification may be needed to prevent adverse effects from cool dry gas. Heated humidifier provides better CO(2) clearance and lower work of breathing than does heat-and-moisture exchanger, because heated humidifier adds less dead space. PMID:19111108

Nava, Stefano; Navalesi, Paolo; Gregoretti, Cesare

2009-01-01

62

Frequency and Intensive Care Related Risk Factors of Pneumothorax in Ventilated Neonates  

PubMed Central

Objectives. Relationships of mechanical ventilation to pneumothorax in neonates and care procedures in particular are rarely studied. We aimed to evaluate the relationship of selected ventilator variables and risk events to pneumothorax. Methods. Pneumothorax was defined as accumulation of air in pleural cavity as confirmed by chest radiograph. Relationship of ventilator mode, selected settings, and risk procedures prior to detection of pneumothorax was studied using matched controls. Results. Of 540 neonates receiving mechanical ventilation, 10 (1.85%) were found to have pneumothorax. Respiratory distress syndrome, meconium aspiration syndrome, and pneumonia were the underlying lung pathology. Pneumothorax mostly (80%) occurred within 48 hours of life. Among ventilated neonates, significantly higher percentage with pneumothorax received mandatory ventilation than controls (70% versus 20%; P < 0.01). Peak inspiratory pressure >20?cm H2O and overventilation were not significantly associated with pneumothorax. More cases than controls underwent care procedures in the preceding 3 hours of pneumothorax event. Mean airway pressure change (P = 0.052) and endotracheal suctioning (P = 0.05) were not significantly associated with pneumothorax. Reintubation (P = 0.003), and bagging (P = 0.015) were significantly associated with pneumothorax. Conclusion. Pneumothorax among ventilated neonates occurred at low frequency. Mandatory ventilation and selected care procedures in the preceding 3 hours had significant association.

Bhat Yellanthoor, Ramesh; Ramdas, Vidya

2014-01-01

63

Frequency of hypoxic events in patients on a mechanical ventilator  

PubMed Central

Background: Mechanical ventilation is an important tool in the management of respiratory failure in the critically ill patient. Although mechanical ventilation can be a life-saving intervention, it is also known to carry several side-effects and risks. Adequate oxygenation is one of the primary goals of mechanical ventilation. However, while on mechanical ventilation, patients frequently experience hypoxic events resulting from various causes, which need to be properly evaluated and treated. Materials and Methods: Data were obtained by prospectively reviewing all intensive care admissions during the period from March 2009 to March 2010 at a 651-bed urban medical center. Patients who developed hypoxemia (oxygen saturation ?88% and a PaO2?60 torrs) while on mechanical ventilation were investigated for the cause of hypoxic event. Results: During the study period, 955 patients required mechanical ventilation from which 79 developed acute hypoxia. The causes of acute hypoxia in decreasing order of occurrences were pulmonary edema, atelectasis, pneumothorax, pneumonia, ARDS, endotracheal tube malfunction, airway bleeding, and pulmonary embolism. Conclusions: Appropriate evaluation of all hypoxic events must begin at the bedside. A step-by-step approach must include a thorough physical examination. Evaluation of the endotracheal tube can immediately reveal dislodgement, bleeding, and secretions. Correlation of physical examination findings with those on chest radiograph is essential. Each hypoxic event requires a different intervention depending on its etiology. Instead of simply increasing the fraction of oxygen in the inspired air to overcome hypoxia, a concerted effort in appropriate problem solving can reduce the likelihood of an incorrect diagnosis and management response.

Mahmood, Nader A.; Chaudry, Fawad A.; Azam, Hamad; Ali, M. Imran; Khan, M. Anees

2013-01-01

64

Delirium during Weaning from Mechanical Ventilation  

PubMed Central

Background. We compare the incidence of delirium before and after extubation and identify the risk factors and possible predictors for the occurrence of delirium in this group of patients. Methods. Patients weaned from mechanical ventilation (MV) and extubated were included. The assessment of delirium was conducted using the confusion assessment method for the ICU and completed twice per day until discharge from the intensive care unit. Results. Sixty-four patients were included in the study, 53.1% of whom presented with delirium. The risk factors of delirium were age (P = 0.01), SOFA score (P = 0.03), APACHE score (P = 0.01), and a neurological cause of admission (P = 0.01). The majority of the patients began with delirium before or on the day of extubation. Hypoactive delirium was the most common form. Conclusion. Acute (traumatic or medical) neurological injuries were important risk factors in the development of delirium. During the weaning process, delirium developed predominantly before or on the same day of extubation and was generally hypoactive (more difficult to detect). Therefore, while planning early prevention strategies, attention must be focused on neurological patients who are receiving MV and possibly even on patients who are still under sedation.

Osaku, Erica Fernanda; Costa, Claudia Rejane Lima de Macedo; Candia, Maria Fernanda; Toccolini, Beatriz; Covatti, Caroline; Costa, Nicolle Lamberti; Nogueira, Sandy Teixeira; Ogasawara, Suely Mariko; de Albuquerque, Carlos Eduardo; Piana, Pitagoras Augusto; Jorge, Amaury Cezar; Duarte, Pericles Almeida Delfino

2014-01-01

65

Enclosure Smoke Filling and Management with Mechanical Ventilation  

Microsoft Academic Search

Enclosure smoke filling and management are addressed from the standpoint of the volumetric flow rates commonly used for mechanical ventilation system design. In this context, fire-induced gasexpans ion istreated asa volumetric s ource term. A two-layer analysis developed previously for enclosure smoke filling without mechanical ventilation is extended to consider the impact of mechanical ventilation on smoke layer descent rates

Frederick W. Mowrer

2002-01-01

66

Enclosure Smoke Filling and Management with Mechanical Ventilation  

Microsoft Academic Search

Enclosure smoke filling and management are addressed from the standpoint of the volumetric flow rates commonly used for mechanical ventilation system design. In this context, fire-induced gas expansion is treated as a volumetric source term. A two-layer analysis developed previously for enclosure smoke filling without mechanical ventilation is extended to consider the impact of mechanical ventilation on smoke layer descent

Frederick W. Mowrer

2002-01-01

67

Expectations and Outcomes of Prolonged Mechanical Ventilation  

PubMed Central

Objective: Prolonged mechanical ventilation (PMV) provision is increasing markedly despite poor patient outcomes. Misunderstanding prognosis in the PMV decision making process could provide an explanation to this phenomenon. Therefore, we aimed to compare PMV decision makers' expectations for long-term patient outcomes with prospectively observed outcomes. Design, Setting, and Patients: 126 patients undergoing PMV, their surrogates, and their intensive care unit physicians were enrolled consecutively (total n=378) at an academic medical center between April 2006 and April 2007 and followed prospectively for one year. Measurements: Participants were interviewed at the time of tracheostomy placement about their expectations for one-year patient survival, functional status, and quality of life. These expectations were then compared to observed one-year outcomes measured with validated questionnaires. Results: One-year follow up was 100%, with the exception of patient death or cognitive inability to complete interviews. At one year, only 11 (9%) patients were alive and independent of major functional status limitations. Most surrogates reported high baseline expectations for one-year patient survival (117 [93%]), functional status (90 [71%]), and quality of life (105 [83%]). In contrast, fewer physicians described high expectations for survival (54 [43%]), functional status (7 [6%]), and quality of life (5 [4%]). Surrogate-physician pair concordance in expectations was poor (all ?<0.08), as was their accuracy in outcome prediction (range 23-44%). Just 33 (26%) surrogates reported that physicians discussed what to expect for patients' likely future survival, general health, and caregiving needs. Conclusions: One-year patient outcomes for PMV patients were significantly worse than expected by patients' surrogates and physicians. Lack of prognostication about outcomes, discordance between surrogates and physicians about potential outcomes, and surrogates' unreasonably optimistic expectations appear to be potentially modifiable deficiencies in surrogate-physician interactions.

Cox, Christopher E.; Martinu, Tereza; Sathy, Shailaja J.; Clay, Alison S.; Chia, Jessica; Gray, Alice L.; Olsen, Maren K.; Govert, Joseph A.; Carson, Shannon S.; Tulsky, James A.

2009-01-01

68

[Perspectives in mechanical ventilation in ARDS].  

PubMed

Despite more than 25 years of extensive research, the mortality of ARDS patients remains high. The inflammatory process within the lung and the associated gas exchange disturbances require an aggressive ventilatory regimen, which itself may harm the lung. Therapeutic measures which are used to reduce iatrogenic damage to the lung are pressure controlled mechanical ventilation in combination with PEEP and permissive hypercapnia, dehydration and extracorporeal gas exchange. At present, new strategies such as intratracheal instillation of surfactant, partial liquid ventilation and inhalation of nitric oxide (NO) are being evaluated. Surfactant reduces the surface tension, forming a monomolecular layer at the air/tissue interface. It thereby decreases the forces necessary to expand the alveoli and prevents alveoli with small diameter from collapsing. In ARDS, a disturbance of surfactant synthesis, function and re-uptake is the rationale for treatment with exogenous surfactant. Initial clinical results suggest a limited positive effect independently of the surfactant preparation used, the dose and the application mode. Experience with partial liquid ventilation with perfluorocarbons in ARDS has also been reported. Perfluorocarbons are liquids with a high binding capacity for oxygen and carbon dioxide. During normal mechanical ventilation with gas, repetitive doses of perfluorocarbons are instilled into the lungs up to a volume equal to the functional residual capacity. The liquid is pushed into collapsed alveoli and keeps them open by reducing the surface tension. First clinical studies have demonstrated the possible improvement in pulmonary gas exchange. In ARDS, inhalation of NO may cause a predominantly selective vasodilation in blood vessels of ventilated lung regions, resulting in an increase in PaO2 and a decrease in pulmonary artery pressure. The effect of NO on the pulmonary vasculature also induces a reduction in right ventricular afterload and also in pulmonary capillary pressure, which may lead to a faster resolution of pulmonary edema. However, in spite of the promising results of these new strategies, further studies are needed to evaluate their influence on morbidity and mortality. PMID:9289830

Max, M; Kaisers, U; Rossaint, R

1997-06-14

69

Principles of mechanical ventilation--a critical review.  

PubMed

This article is the first of a two-part review focusing on mechanical ventilation, with particular emphasis on non-invasive ventilation when managing patients suffering from respiratory failure. This article explores the principles underpinning artificial ventilation, explains the difference between positive and negative pressure ventilation, and differentiates between invasive and non-invasive modes of ventilation. Finally it examines the various operational features, flexibility in use and limitations that artificial ventilation therapy presents. Optimum ventilatory practice requires knowledge to ensure the choosing of the 'right' ventilator. It ensures informed practice and maintains optimum patient safety. PMID:19717989

Pertab, Dhanishwar

70

Clinical review: Independent lung ventilation in critical care  

PubMed Central

Independent lung ventilation (ILV) can be classified into anatomical and physiological lung separation. It requires either endobronchial blockade or double-lumen endotracheal tube intubation. Endobronchial blockade or selective double-lumen tube ventilation may necessitate temporary one lung ventilation. Anatomical lung separation isolates a diseased lung from contaminating the non-diseased lung. Physiological lung separation ventilates each lung as an independent unit. There are some clear indications for ILV as a primary intervention and as a rescue ventilator strategy in both anatomical and physiological lung separation. Potential pitfalls are related to establishing and maintaining lung isolation. Nevertheless, ILV can be used in the intensive care setting safely with a good understanding of its limitations and potential complications.

Anantham, Devanand; Jagadesan, Raghuram; Tiew, Philip Eng Cher

2005-01-01

71

Carbon Dioxide and Oxygen Levels in Disposable Individually Ventilated Cages after Removal from Mechanical Ventilation  

PubMed Central

Disposable individually ventilated cages have lids that restrict air exchange when the cage is not mechanically ventilated. This design feature may cause intracage CO2 to increase and O2 to decrease (hypercapnic and hypoxic conditions, respectively) when the electrical supply to the ventilated rack fails, the ventilated rack malfunctions, cages are docked in the rack incorrectly, or cages are removed from the ventilated rack for extended periods of time. We investigated how quickly hypercapnic and hypoxic conditions developed within disposable individually ventilated cages after removal from mechanical ventilation and compared the data with nondisposable static cages, disposable static cages, and unventilated nondisposable individually ventilated cages. When disposable individually ventilated cages with 5 adult mice per cage were removed from mechanical ventilation, CO2 concentrations increased from less than 1% at 0 h to approximately 5% at 3 h and O2 levels dropped from more than 20% at 0 h to 11.7% at 6 h. The breathing pattern of the mice showed a prominent abdominal component (hyperventilation). Changes were similar for 4 adult mice per cage, reaching at least 5% CO2 at 4 h and 13.0% O2 at 6 h. For 3 or 2 mice per cage, values were 4.6% CO2 and 14.7% O2 and 3.04% CO2 and 17.1% O2, respectively, at 6 h. These results document that within disposable individually ventilated cages, a hypercapnic and hypoxic microenvironment develops within hours in the absence of mechanical ventilation.

Nagamine, Claude M; Long, C Tyler; McKeon, Gabriel P; Felt, Stephen A

2012-01-01

72

Sizing the lung of mechanically ventilated patients  

Microsoft Academic Search

Introduction  This small observational study was motivated by our belief that scaling the tidal volume in mechanically ventilated patients\\u000a to the size of the injured lung is safer and more 'physiologic' than scaling it to predicted body weight, i.e. its size before\\u000a it was injured. We defined Total Lung Capacity (TLC) as the thoracic gas volume at an airway pressure of

Jennifer S Mattingley; Steven R Holets; Richard A Oeckler; Randolph W Stroetz; Curtis F Buck; Rolf D Hubmayr

2011-01-01

73

Mechanical ventilation in ICUs in Poland: A multi-center point-prevalence study  

PubMed Central

Background Mechanical ventilation is the primary method of supporting organ function in patients treated in intensive care units (ICUs). Lung damage from mechanical ventilation can be avoided by using the correct ventilation modes. This study was designed to assess the epidemiology and treatment strategies of patients receiving mechanical ventilation in ICUs in Poland. Material/Methods This study was done using a point-prevalence methodology. Questionnaires requesting demographic data, indications for ventilation, variables involved in ventilation, airway access, methods of sedation, and mode of weaning were sent to 148 ICUs. Results Eighty-three ICUs took part in the study. The rate of ventilated patients was 73.6%. The indications for mechanical ventilation were: acute respiratory failure (40%), coma (40%), chronic obstructive pulmonary disease (COPD) exacerbation (14%), and neuromuscular diseases (5%). Patients were ventilated by orotracheal tube (58%), tracheostomy tube (41%), and mask/helmet (1%). The mean tidal volume was 8 ml/kg and positive end-expiratory pressure was commonly used. The mean oxygen concentration was 40%. Synchronized intermittent mandatory ventilation with pressure support was the most frequently used ventilatory mode. Benzodiazepine and opioids were used for sedation in 91% of centers. A systematic testing of the depth of sedation was performed at 48% surveyed ICUs. Ventilation monitoring with biomechanical methods was used at 53% of centers. Conclusions Mechanical ventilation is commonly used in ICUs in Poland. Almost half of the ventilated patients had extrapulmonary indications. Patients were ventilated with low concentrations of oxygen, and positive end-expiratory pressure (PEEP) was commonly employed.

Kubler, Andrzej; Maciejewski, Dariusz; Adamik, Barbara; Kaczorowska, Malgorzata

2013-01-01

74

Louisiana's Ventilator Assisted Care Program: Case Management Services to Link Tertiary with Community-Based Care.  

ERIC Educational Resources Information Center

The Ventilator Assisted Care Program provides centralized case management services to ventilator-using youths and their families in Louisiana. Case managers develop individualized, comprehensive plans to be implemented locally using community resources; plans are based on needs identified by tertiary care providers and family members and are…

Kirkhart, Kathryn A.; And Others

1988-01-01

75

The Changing Epidemiology of Mechanical Ventilation: A Population-Based Study  

Microsoft Academic Search

The number of critical care beds in the United States has been increasing considerably, but it is unclear how these additional beds have been used. Mechanical ventilation for acute respiratory failure almost always demands ICU care and is likely to be a reliable indicator of critical care resource requirements on a population level. The objective of this study was to

Shannon S. Carson; Christopher E. Cox; George M. Holmes; Ann Howard; Timothy S. Carey

2006-01-01

76

Protocolized eye care prevents corneal complications in ventilated patients in a medical intensive care unit  

PubMed Central

Background: Eye care is an essential component in the management of critically ill patients. Standardized eye care can prevent corneal complications in ventilated patients. Objective: This study was designed to compare old and new practices of corneal care for reduction in corneal complications in ventilated patients. Methods: This study was done in three phases each of six month duration. Phase 1 was the ongoing practice of eye care in the unit. Before the start of phase 2, a new protocol was made for eye care. Corneal complications were observed in terms of haziness, dryness, and ulceration. All nursing staffs were educated and made compliant with the new protocol. In phase 2, a follow-up audit was done to check the effectiveness and compliance to protocol. In phase 3, a follow-up audit was started 3 months after phase 2. Results: In phase 1, total ventilated patients were 40 with 240 ventilator days. The corneal dryness rate was 40 per 1000 ventilator days while the haziness and ulceration rate was 16 per 1000 ventilator days each. In the second phase 2, total ventilated patients were 53 making 561 ventilator days. The rate of corneal haziness and dryness was 3.52 and 1.78 per 1000 ventilator days, respectively, with no case of corneal ulceration. In phase 3, the number of ventilated patients was 91 with 1114 ventilator days. The corneal dryness rate was 2.69 while the haziness and ulceration rate was 1.79 each. Conclusion: Protocolized eye care can reduce the risk of corneal complications in ventilated patients.

Azfar, Mohammad Feroz; Khan, Muhammad Faisal; Alzeer, Abdulaziz H.

2013-01-01

77

Depressive Disorders during Weaning from Prolonged Mechanical Ventilation  

PubMed Central

Purpose Patients who require mechanical ventilation are at risk of emotional stress because of total dependence on a machine for breathing. The stress may negatively impact ventilator weaning and survival. The purpose of this study was to determine whether depressive disorders in patients being weaned from prolonged mechanical ventilation are linked to weaning failure and decreased survival. Methods A prospective study of 478 consecutive patients transferred to a long-term acute care hospital for weaning from prolonged ventilation was undertaken. A clinical psychologist conducted a psychiatric interview to assess for the presence of depressive disorders. Results Of the 478 patients, 142 had persistent coma or delirium and were unable to be evaluated for depressive disorders. Of the remaining 336 patients, 142 (42%) were diagnosed with depressive disorders. In multivariate analysis, co-morbidity score (odds ratio [OR], 1.23, p=0.007), functional dependence before the acute illness (OR, 1.70, p=0.03), and history of psychiatric disorders (OR, 3.04, p=0.0001) were independent predictors of depressive disorders. The rate of weaning failure was higher in patients with depressive disorders than in those without such disorders (61% versus 33%, p=0.0001), as was mortality (24% versus 10%, p=0.0008). The presence of depressive disorders was independently associated with mortality (OR, 4.3; p=0.0002); age (OR, 1.06; p=0.001) and co-morbidity score (OR, 1.24; p=0.02) also predicted mortality. Conclusion Depressive disorders were diagnosed in 42% of patients who are being weaned from prolonged ventilation. Patients with depressive disorders were more likely to experience weaning failure and death.

Jubran, Amal; Lawm, Gerald; Kelly, Joanne; Duffner, Lisa A.; Gungor, Gokay; Collins, Eileen G.; Lanuza, Dorothy M.; Hoffman, Leslie A.; Tobin, Martin J.

2010-01-01

78

Impact of the ventilator bundle on ventilator-associated pneumonia in intensive care unit  

PubMed Central

Objectives The ventilator bundle is being promoted to prevent adverse events in ventilated patients including ventilator-associated pneumonia (VAP). We aimed to: (i) examine adoption of the ventilator bundle elements; (ii) determine effectiveness of individual elements and setting characteristics in reducing VAP; (iii) determine effectiveness of two infection-specific elements on reducing VAP; and, (iv) assess crossover effects of complying with VAP elements on central line-associated bloodstream infections. Design Cross-sectional survey. Setting Four hundred and fifteen ICUs from 250 US hospitals. Participants Managers/directors of infection prevention and control departments. Interventions Adoption and compliance with ventilator bundle elements. Main Outcome Measures VAP rates. Results The mean VAP rate was 2.7/1000 ventilator days. Two-thirds (n = 284) reported presence of the full ventilator bundle policy. However, only 66% (n = 188/284) monitored implementation; of those, 39% (n = 73/188) reported high compliance. Only when an intensive care unit (ICU) had a policy, monitored compliance and achieved high compliance were VAP rates lower. Compliance with individual elements or just one of two infection-related element had no impact on VAP (? = ?0.79, P= 0.15). There was an association between complying with two infection elements and lower rates (? = ?1.81, P< 0.01). There were no crossover effects. Presence of a full-time hospital epidemiologist (HE) was significantly associated with lower VAP rates (? = ?3.62, P< 0.01). Conclusions The ventilator bundle was frequently present but not well implemented. Individual elements did not appear effective; strict compliance with infection elements was needed. Efforts to prevent VAP may be successful in settings of high levels of compliance with all infection-specific elements and in settings with full-time HEs.

Pogorzelska, Monika; Stone, Patricia W.; Furuya, E. Yoko; Perencevich, Eli N.; Larson, Elaine L.; Goldmann, Donald; Dick, Andrew

2011-01-01

79

[Mechanical ventilation in chronic ventilatory insufficiency].  

PubMed

Mechanical ventilation has become an important treatment option in chronic ventilatory failure. There are different diseases which lead to ventilatory failure and to home mechanical ventilation (HMV). A primary loss of in- and expiratory muscle strength is the reason for respiratory deterioration in neuromuscular disease. In most of these diseases ventilatory failure develops because of the progressive character of muscular damage. Initially, ventilatory failure can be found during night-time. In the case of hypercapnia at daytime, life expectancy is strongly reduced, especially in amyotrophic lateral sclerosis and Duchenne muscular dystrophy. HMV leads to a prolongation of life and to an increase in quality of life, if bulbar involvement is not severe. Impressive clinical improvements under HMV have been found in restrictive disorders of the rib cage like kyphoscoliosis or posttuberculosis sequelae, with an increase of quality of life, walking distance and a decrease in pulmonary hypertension. Only few data are published about long-term results of HMV in Obesity Hypoventilation. In terms of retrospective analyses of clinical data HMV seems to improve survival in this population. Some patients only need CPAP treatment, but most patients have to be treated with ventilatory support. The application of HMV in patients with chronic ventilatory failure due to chronic obstructive pulmonary disease (COPD) is growing, but there are controversial results in randomised clinical trials. Analysis of these data suggest better results of HMV in patients with severe hypercapnia, with the application of higher effective ventilatory pressure and a ventilator mode with a significant reduction in the work of breathing. Under such conditions HMV leads to a reduction of hypercapnia, an improvement in sleep quality, walking distance and quality of life, but until now there is no evidence in reduction of mortality in COPD. PMID:17620231

Schucher, B; Magnussen, H

2007-10-01

80

Mechanical ventilation: past lessons and the near future  

PubMed Central

The ability to compensate for life-threatening failure of respiratory function is perhaps the signature technology of intensive care medicine. Unchanging needs for providing effective life-support with minimized risk and optimized comfort have been, are now, and will be the principal objectives of providing mechanical ventilation. Important lessons acquired over nearly half-a-century of ICU care have brought us closer to meeting them, as technological advances in instrumentation now effectively put this hard-won knowledge into action. Rising demand in the face of economic constraints is likely to drive future innovations focused on reducing the need for user input, automating multi-element protocols, and carefully monitoring the patient for progress and complications.

2013-01-01

81

Mechanical ventilation: past lessons and the near future.  

PubMed

The ability to compensate for life-threatening failure of respiratory function is perhaps the signature technology of intensive care medicine. Unchanging needs for providing effective life-support with minimized risk and optimized comfort have been, are now, and will be the principal objectives of providing mechanical ventilation. Important lessons acquired over nearly half-a-century of ICU care have brought us closer to meeting them, as technological advances in instrumentation now effectively put this hard-won knowledge into action. Rising demand in the face of economic constraints is likely to drive future innovations focused on reducing the need for user input, automating multi-element protocols, and carefully monitoring the patient for progress and complications. PMID:23514222

Marini, John J

2013-01-01

82

Improved control of gas humidity in neonatal intensive care ventilators  

Microsoft Academic Search

Difficulties experienced by nursing staff in controlling humidity in neonatal intensive care ventilators are shown to originate in the use of a single control, namely a heater, to condition two parameters, namely temperature and humidity, at the inlet to the inspiratory tube. It is shown that better control can be achieved by separating the gas flow through the humidifier into

Tim Drew; Alan Vardy

1998-01-01

83

The fluid mechanics of natural ventilation  

Microsoft Academic Search

Natural ventilation of buildings is the flow generated by temperature differences and by the wind. Modern buildings have extreme designs with large, tall open plan spaces and large cooling requirements. Natural ventilation offers a means of cooling these buildings and providing good indoor air quality. The essential feature of ventilation is an exchange between an interior space and the external

Paul Linden

1999-01-01

84

Inhaled antibiotics in mechanically ventilated patients.  

PubMed

During the last decade, inhaled antibiotics, especially colistin, has been widely used worldwide as a therapeutic option, supplementary to conventional intravenous antibiotics, for the treatment of multidrug-resistant (MDR) Gram-negative nosocomial and ventilator-associated pneumonia (VAP). Antimicrobial aerosols are commonly used in mechanically ventilated patients with VAP, although information regarding their efficacy and optimal technique of administration has been limited. Recent studies showed that the administration of inhaled antibiotics in addition to systemic antibiotics provided encouraging results associated with low toxicity for the management of VAP mainly due to MDR Gram negative bacteria. Although the theory behind aerosolized administration of antibiotics seems to be sound, there are limited data available to support the routine use of this modality since very few randomized controlled trials (RCTs) have still examined the efficacy of this approach in patients with VAP. Additionally, this route of antibiotic delivery has not been approved until now neither by the FDA nor by the European Medicines Agency (EMEA) in patients with VAP. However, since the problem of VAP due to MDR bacteria has been increased worldwide RCTs are urgently needed in order to prove the safety, efficiency and efficacy of inhaled antimicrobial agents administered alone or in conjunction with parenteral antibiotics for the management of VAP in critically ill patients. Indeed, more data are needed to establish the appropriate role of inhaled antibiotics for the treatment of VAP. PMID:24107830

Michalopoulos, A S; Falagas, M E

2014-02-01

85

Early physical and occupational therapy in mechanically ventilated, critically ill patients: a randomised controlled trial  

Microsoft Academic Search

Summary Background Long-term complications of critical illness include intensive care unit (ICU)-acquired weakness and neuropsychiatric disease. Immobilisation secondary to sedation might potentiate these problems. We assessed the effi cacy of combining daily interruption of sedation with physical and occupational therapy on functional outcomes in patients receiving mechanical ventilation in intensive care. Methods Sedated adults (?18 years of age) in the

William D Schweickert; Mark C Pohlman; Anne S Pohlman; Celerina Nigos; Amy J Pawlik; Cheryl L Esbrook; Linda Spears; Megan Miller; Mietka Franczyk; Deanna Deprizio; Gregory A Schmidt; Amy Bowman; Rhonda Barr; Kathryn E McCallister; Jesse B Hall; John P Kress

2009-01-01

86

Oral decontamination for prevention of pneumonia in mechanically ventilated adults: systematic review and meta-analysis  

PubMed Central

Objective To evaluate the effect of oral decontamination on the incidence of ventilator associated pneumonia and mortality in mechanically ventilated adults. Design Systematic review and meta-analysis. Data sources Medline, Embase, CINAHL, the Cochrane Library, trials registers, reference lists, conference proceedings, and investigators in the specialty. Review methods Two independent reviewers screened studies for inclusion, assessed trial quality, and extracted data. Eligible trials were randomised controlled trials enrolling mechanically ventilated adults that compared the effects of daily oral application of antibiotics or antiseptics with no prophylaxis. Results 11 trials totalling 3242 patients met the inclusion criteria. Among four trials with 1098 patients, oral application of antibiotics did not significantly reduce the incidence of ventilator associated pneumonia (relative risk 0.69, 95% confidence interval 0.41 to 1.18). In seven trials with 2144 patients, however, oral application of antiseptics significantly reduced the incidence of ventilator associated pneumonia (0.56, 0.39 to 0.81). When the results of the 11 trials were pooled, rates of ventilator associated pneumonia were lower among patients receiving either method of oral decontamination (0.61, 0.45 to 0.82). Mortality was not influenced by prophylaxis with either antibiotics (0.94, 0.73 to 1.21) or antiseptics (0.96, 0.69 to 1.33) nor was duration of mechanical ventilation or stay in the intensive care unit. Conclusions Oral decontamination of mechanically ventilated adults using antiseptics is associated with a lower risk of ventilator associated pneumonia. Neither antiseptic nor antibiotic oral decontamination reduced mortality or duration of mechanical ventilation or stay in the intensive care unit.

Ruest, Annie; Meade, Maureen O; Cook, Deborah J

2007-01-01

87

Airway pressure release ventilation: an alternative mode of mechanical ventilation in acute respiratory distress syndrome.  

PubMed

Acute respiratory distress syndrome (ARDS) results in collapse of alveoli and therefore poor oxygenation. In this article, we review airway pressure release ventilation (APRV), a mode of mechanical ventilation that may be useful when, owing to ARDS, areas of the lungs are collapsed and need to be reinflated ("recruited"), avoiding cyclic alveolar collapse and reopening. PMID:21285342

Modrykamien, Ariel; Chatburn, Robert L; Ashton, Rendell W

2011-02-01

88

Weaning of mechanically ventilated chronic obstructive pulmonary disease patients by using non-invasive positive pressure ventilation: A prospective study  

PubMed Central

Background: Chronic obstructive pulmonary disease (COPD) patients frequently pose difficulty in weaning from invasive mechanical ventilation (MV). Prolonged invasive ventilation brings along various complications. Non-invasive positive pressure ventilation (NIPPV) is proposed to be a useful weaning modality in such cases. Objective: To evaluate the usefulness of NIPPV in weaning COPD patients from invasive MV, and compare it with weaning by conventional pressure support ventilation (PSV). Materials and Methods: For this prospective randomized controlled study, we included 50 COPD patients with type II respiratory failure requiring initial invasive MV. Upon satisfying weaning criteria and failing a t-piece weaning trial, they were randomized into two groups: Group I (25 patients) weaned by NIPPV, and group II (25 patients) weaned by conventional PSV. The groups were similar in terms of disease severity, demographic, clinical and biochemical parameters. They were compared in terms of duration of MV, weaning duration, length of intensive care unit (ICU) stay, occurrence of nosocomial pneumonia and outcome. Results: Statistically significant difference was found between the two groups in terms of duration of MV, weaning duration, length of ICU stay, occurrence of nosocomial pneumonia and outcome. Conclusion: NIPPV appears to be a promising weaning modality for mechanically ventilated COPD patients and should be tried in resource-limited settings especially in developing countries.

Mishra, Mayank; Chaudhri, Sudhir; Tripathi, Vidisha; Verma, Ajay K.; Sampath, Arun; Chauhan, Nishant K.

2014-01-01

89

Very Low Birth Weight Infant Necessitating Nissen Fundoplication for Weaning off the Mechanical Ventilator  

PubMed Central

Gastro-esophageal reflux (GER) is one of the common problems of neonatal intensive care units. Although this condition does not always need to be treated, it occasionally causes clinically serious consequences. Initial management is medical; however, in some cases surgery might be required. A premature neonate with birth weight of 1370 grams was managed in our ICU. The patient was mechanical ventilator dependent due to GER. The patient needed Nissen fundoplication for successfully weaning off the ventilator.

Koksal, Nilgun; Ozkan, Hilal; Dogan, Pelin; Bagc?, Onur; Dogruyol, Hasan; Gurp?nar, Arif

2014-01-01

90

Mechanical ventilation competencies of the respiratory therapist in 2015 and Beyond.  

PubMed

The evolution of critical care and mechanical ventilation has been dramatic and rapid over the last 10 years and can be expected to continue at this pace into the future. As a result, the competencies of the respiratory therapist regarding mechanical ventilation in 2015 and beyond are expected to also markedly increase. Respiratory therapists are expected to be the experts on the mechanical ventilator and all aspects of the application of mechanical ventilation. They will be considered consultants on all aspect of ventilatory support. This requires an expanded education in a number of areas. To achieve these levels of competency, as recommended by the third "2015 and Beyond" conference, the entry level education of the respiratory therapist of the future must be at the baccalaureate level. PMID:23709202

Kacmarek, Robert M

2013-06-01

91

Update on modalities of mechanical ventilators  

Microsoft Academic Search

Recent advances in ventilator technology have often not been confirmed by randomised trials and instead serious shortcomings have been highlighted. Ventilation modes should only be introduced into routine clinical practice when proved efficacious in appropriately designed studies and no adverse outcomes identified by long term follow up.

A Greenough

2002-01-01

92

Acute kidney injury is an independent risk factor for pediatric intensive care unit mortality, longer length of stay and prolonged mechanical ventilation in critically ill children: a two-center retrospective cohort study  

PubMed Central

Introduction In adults, small (< 50%) serum creatinine (SCr) increases predict mortality. It is unclear whether different baseline serum creatinine (bSCr) estimation methods affect findings of acute kidney injury (AKI)-outcome associations. We characterized pediatric AKI, evaluated the effect of bSCr estimation approaches on AKI-outcome associations and evaluated the use of small SCr increases to predict AKI development. Methods We conducted a retrospective cohort database study of children (excluding postoperative cardiac or renal transplant patients) admitted to two pediatric intensive care units (PICUs) for at least one night in Montreal, QC, Canada. The AKI definition was based on the Acute Kidney Injury Network staging system, excluding the requirement of SCr increase within 48 hours, which was impossible to evaluate on the basis of our data set. We estimated bSCr two ways: (1) the lowest SCr level in the three months before admission or the average age- and gender-based norms (the standard method) or (2) by using average norms in all patients. Outcomes were PICU mortality and length of stay as well as required mechanical ventilation. We used multiple logistic regression analysis to evaluate AKI risk factors and the association between AKI and mortality. We used multiple linear regression analysis to evaluate the effect of AKI on other outcomes. We calculated diagnostic characteristics for early SCr increase (< 50%) to predict AKI development. Results Of 2,106 admissions (mean age ± SD = 5.0 ± 5.5 years; 47% female), 377 patients (17.9%) developed AKI (using the standard bSCr method) during PICU admission. Higher Pediatric Risk of Mortality score, required mechanical ventilation, documented infection and having a bSCr measurement were independent predictors of AKI development. AKI was associated with increased mortality (adjusted odds ratio (OR) = 3.7, 95% confidence interval (95% CI) = 2.1 to 6.4, using the standard bSCr method; OR = 4.5, 95% CI = 2.6 to 7.9, using normative bSCr values in all patients). AKI was independently associated with longer PICU stay and required mechanical ventilation. In children with no admission AKI, the initial percentage SCr increase predicted AKI development (area under the curve = 0.67, 95% CI = 0.60 to 0.74). Conclusions AKI is associated with increased mortality and morbidity in critically ill children, regardless of the bSCr used. Paying attention to small early SCr increases may contribute to early AKI diagnosis in conjunction with other new AKI biomarkers.

2011-01-01

93

Critical pertussis in a young infant requiring mechanical ventilation.  

PubMed

Pertussis may likely be misdiagnosed in its initial or catarrhal phase as a common respiratory infection. The earlier diagnosis of pertussis really depends on the capability of the medical professional especially in the first line public health services. The lack of awareness in diagnosis of severe pertussis as one of the causes of severe respiratory problems may likely misdiagnose pertussis as respiratory failure or even septic shock. In fact, pertussis may manifest as a critical pertussis which can be fatal due to the respiratory failure that require pediatric intensive care unit using mechanical ventilation. We reported a confirmed pertussis case of a 7-weeks-old female infant referred to our tertiary hospital with gasping leading to respiratory failure and septic shock requiring mechanical ventilation, aggressive fluid therapy, and antibiotics. Pertussis was diagnosed late during the course of illness when the patient was hospitalized. Improvement was noted after administering macrolide which gave a good response. Bordetella pertussis isolation from Bordet-Gengou media culture yielded positive result. PMID:23738154

Nataprawira, Heda Melinda; Somasetia, Dadang Hudaya; Sudarwati, Sri; Kadir, Minerva; Sekarwana, Nanan

2013-01-01

94

Critical Pertussis in a Young Infant Requiring Mechanical Ventilation  

PubMed Central

Pertussis may likely be misdiagnosed in its initial or catarrhal phase as a common respiratory infection. The earlier diagnosis of pertussis really depends on the capability of the medical professional especially in the first line public health services. The lack of awareness in diagnosis of severe pertussis as one of the causes of severe respiratory problems may likely misdiagnose pertussis as respiratory failure or even septic shock. In fact, pertussis may manifest as a critical pertussis which can be fatal due to the respiratory failure that require pediatric intensive care unit using mechanical ventilation. We reported a confirmed pertussis case of a 7-weeks-old female infant referred to our tertiary hospital with gasping leading to respiratory failure and septic shock requiring mechanical ventilation, aggressive fluid therapy, and antibiotics. Pertussis was diagnosed late during the course of illness when the patient was hospitalized. Improvement was noted after administering macrolide which gave a good response. Bordetella pertussis isolation from Bordet-Gengou media culture yielded positive result.

Nataprawira, Heda Melinda; Somasetia, Dadang Hudaya; Sudarwati, Sri; Kadir, Minerva; Sekarwana, Nanan

2013-01-01

95

Newer modes of mechanical ventilation for the neonate.  

PubMed

For decades, the overwhelming majority of infants requiring mechanical ventilation for respiratory failure were treated with standard time-cycled, pressure-limited intermittent mandatory ventilation. Technologic advances in the 1990s brought forth sophisticated transducers and microprocessor-based mechanical ventilators that enabled implementation of many newer modes of mechanical ventilation. Some of these are volume-targeted rather than pressure-targeted, and many allow an element of patient control of the ventilator, including initiation and termination of inspiration and control of flow. Some modes are even hybrids, combining the best features of both pressure-targeted and volume-targeted modes. This article reviews the principles and salient clinical features of the newer ventilatory modes for newborns with respiratory failure. PMID:11317048

Donn, S M; Sinha, S K

2001-04-01

96

Ammonia emissions from two mechanically ventilated UK livestock buildings  

NASA Astrophysics Data System (ADS)

Ammonia emission rates from livestock buildings are required to construct an accurate emission inventory for the UK. Ventilation and ammonia emission rates from a fattening pig unit and a broiler house, both mechanically ventilated, were estimated using fan wheel anemometers and thermal converters with a chemiluminescence NO x-analyser to measure the ventilation rate and the ammonia concentration, respectively. The estimated ammonia emission factors were 46.9 and 16.6 kg lu -1 a -1 for the fattening pig unit and the broiler house, respectively. Both emission factors were within the range reported in the literature. A tracer gas (CO) method, based on a constant tracer release rate, was validated for measuring ventilation rates from naturally ventilated livestock buildings. Air inlets and outlets were identified using the air temperature or tracer concentration in the opening. Tracer concentration was found to be a more suitable criterion than temperature. In both houses, a significant correlation between the estimated ventilation rate using the tracer method and the measured ventilation rate using fan wheel anemometers was found. The ventilation rate was underestimated by 12 and 6% for the piggery and broiler house, respectively. The instantaneous ammonia emission derived from the tracer gas method was lower than the ammonia emission derived from the fan wheel anemometer method by 14 and 16% for the piggery and broiler house, respectively. The ventilation and ammonia emission estimates using the tracer method were within acceptable range from the ventilation and emission rates measured using measuring fans, but because of its accuracy and simplicity the fan wheel anemometer method is preferred for long-term measurements of ventilation rate in mechanically ventilated buildings.

Demmers, T. G. M.; Burgess, L. R.; Short, J. L.; Phillips, V. R.; Clark, J. A.; Wathes, C. M.

97

A Porcine Model for Initial Surge Mechanical Ventilator Assessment and Evaluation of Two Limited Function Ventilators  

PubMed Central

Objective To adapt an animal model of acute lung injury for use as a standard protocol for a screening, initial evaluation of limited function, or “surge,” ventilators for use in mass casualty scenarios. Design Prospective, experimental animal study. Setting University research laboratory. Subjects 12 adult pigs. Interventions 12 spontaneously breathing pigs (6 in each group) were subjected to acute lung injury/acute respiratory distress syndrome (ALI/ARDS) via pulmonary artery infusion of oleic acid. Following development of respiratory failure, animals were mechanically ventilated with a limited function ventilator (Simplified Automatic Ventilator [SAVe] I or II; Automedx) for one hour or until the ventilator could not support the animal. The limited function ventilator was then exchanged for a full function ventilator (Servo 900C; Siemens). Measurements and Main Results Reliable and reproducible levels of ALI/ARDS were induced. The SAVe I was unable to adequately oxygenate 5 animals, with PaO2 (52.0 ± 11.1 torr) compared to the Servo (106.0 ± 25.6 torr; p=0.002). The SAVe II was able to oxygenate and ventilate all 6 animals for one hour with no difference in PaO2 (141.8 ± 169.3 torr) compared to the Servo (158.3 ± 167.7 torr). Conclusions We describe a novel in vivo model of ALI/ARDS that can be used to initially screen limited function ventilators considered for mass respiratory failure stockpiles, and is intended to be combined with additional studies to defintively assess appropriateness for mass respiratory failure. Specifically, during this study we demonstrate that the SAVe I ventilator is unable to provide sufficient gas exchange, while the SAVe II, with several more functions, was able to support the same level of hypoxemic respiratory failure secondary to ALI/ARDS for one hour.

Dickson, Robert P; Hotchkin, David L; Lamm, Wayne JE; Hinkson, Carl; Pierson, David J; Glenny, Robb W; Rubinson, Lewis

2013-01-01

98

Mechanical ventilation causes airway distension with proinflammatory sequelae in mice.  

PubMed

The pathogenesis of ventilator-induced lung injury has predominantly been attributed to overdistension or mechanical opening and collapse of alveoli, whereas mechanical strain on the airways is rarely taken into consideration. Here, we hypothesized that mechanical ventilation may cause significant airway distension, which may contribute to the pathological features of ventilator-induced lung injury. C57BL/6J mice were anesthetized and mechanically ventilated at tidal volumes of 6, 10, or 15 ml/kg body wt. Mice were imaged by flat-panel volume computer tomography, and central airways were segmented and rendered in 3D for quantitative assessment of airway distension. Alveolar distension was imaged by intravital microscopy. Functional dead space was analyzed in vivo, and proinflammatory cytokine release was analyzed in isolated, ventilated tracheae. CT scans revealed a reversible, up to 2.5-fold increase in upper airway volume during mechanical ventilation compared with spontaneous breathing. Airway distension was most pronounced in main bronchi, which showed the largest volumes at tidal volumes of 10 ml/kg body wt. Conversely, airway distension in segmental bronchi and functional dead space increased almost linearly, and alveolar distension increased even disproportionately with higher tidal volumes. In isolated tracheae, mechanical ventilation stimulated the release of the early-response cytokines TNF-? and IL-1?. Mechanical ventilation causes a rapid, pronounced, and reversible distension of upper airways in mice that is associated with an increase in functional dead space. Upper airway distension is most pronounced at moderate tidal volumes, whereas higher tidal volumes redistribute preferentially to the alveolar compartment. Airway distension triggers proinflammatory responses and may thus contribute relevantly to ventilator-induced pathologies. PMID:24816486

Nickles, Hannah T; Sumkauskaite, Migle; Wang, Xin; Wegner, Ingmar; Puderbach, Michael; Kuebler, Wolfgang M

2014-07-01

99

Control of Breathing During Mechanical Ventilation: Who Is the Boss?  

PubMed Central

Over the past decade, concepts of control of breathing have increasingly moved from being theoretical concepts to “real world” applied science. The purpose of this review is to examine the basics of control of breathing, discuss the bidirectional relationship between control of breathing and mechanical ventilation, and critically assess the application of this knowledge at the patient’s bedside. The principles of control of breathing remain under-represented in the training curriculum of respiratory therapists and pulmonologists, whereas the day-to-day bedside application of the principles of control of breathing continues to suffer from a lack of outcomes-based research in the intensive care unit. In contrast, the bedside application of the principles of control of breathing to ambulatory subjects with sleep-disordered breathing has out-stripped that in critically ill patients. The evolution of newer technologies, faster real-time computing abilities, and miniaturization of ventilator technology can bring the concepts of control of breathing to the bedside and benefit the critically ill patient. However, market forces, lack of scientific data, lack of research funding, and regulatory obstacles need to be surmounted.

Williams, Kathleen; Hinojosa-Kurtzberg, Marina; Parthasarathy, Sairam

2011-01-01

100

The effects of an oral care practice on incidence of pneumonia among ventilator patients in ICUs of selected hospitals in Isfahan, 2010  

PubMed Central

Background: Oral care plays an inevitable role in health and well-being of patients in intensive care units (ICUs). Poor oral care causes colonization of respiratory pathogens and secondary respiratory infections. Ventilator-associated pneumonia occurs in patients on mechanical ventilation for more than 48 hours. It results in prolonged duration of mechanical ventilation, mortality and health expenses. The present study aimed to review the effects of an oral care practice on the incidence of ventilator-associated pneumonia in patients on mechanical ventilation admitted in ICUs. Materials and Methods: This was a clinical trial study conducted in the ICUs of selected hospitals in Isfahan during 2010. We randomly divided 54 patients into the intervention and control groups. Intubation was performed during the 48 hours before the study. The intervention group received an oral care practice along with brushing and the control group received routine oral care twice daily. The incidence of ventilator-associated pneumonia was diagnosed through clinical pulmonary infection score (CPIS). Findings: The two groups were compared in terms of underlying criteria (APACHE-II). The incidence of ventilator-associated pneumonia did not statistically differ between the intervention and control groups (37% vs. 48.1%; p = 0.41). Conclusions: The results of the present study showed that brushing and standard oral care practice had no effects on ventilator-associated pneumonia. Therefore, the incidence of such complication might be affected by many different factors.

Khalifehzadeh, Asghar; Parizade, Ahmad; Hosseini, Abbas; Yousefi, Hojatollah

2012-01-01

101

An Economic Evaluation of Propofol and Lorazepam for Critically Ill Patients Undergoing Mechanical Ventilation  

PubMed Central

Objective The economic implications of sedative choice in the management of patients receiving mechanical ventilation are unclear because of differences in costs and clinical outcomes associated with specific sedatives. Therefore, we aimed to determine the cost-effectiveness of the most commonly used sedatives prescribed for mechanically ventilated critically ill patients. Design, Setting, and Patients Adopting the perspective of a hospital, we developed a probabilistic decision model to determine if continuous propofol or intermittent lorazepam was associated with greater value when combined with daily awakenings. We also evaluated the comparative value of continuous midazolam in secondary analyses. We assumed that patients were managed in a medical intensive care unit and expected to require ventilation for at least 48 hours. Model inputs were derived from primary analysis of randomized controlled trial data, medical literature, Medicare reimbursement rates, pharmacy databases, and institutional data. Main Results We measured cost-effectiveness as costs per mechanical ventilator-free day within the first 28 days after intubation. Our base-case probabilistic analysis demonstrated that propofol dominated lorazepam in 91% of simulations and, on average, was both $6,378 less costly per patient and associated with over three additional mechanical ventilator-free days. The model did not reveal clinically meaningful differences between propofol and midazolam on costs or measures of effectiveness. Conclusion Propofol has superior value compared to lorazepam when used for sedation among the critically ill who require mechanical ventilation when used in the setting of daily sedative interruption.

Cox, Christopher E.; Reed, Shelby D.; Govert, Joseph A.; Rodgers, Jo E.; Campbell-Bright, Stacy; Kress, John P.; Carson, Shannon S.

2009-01-01

102

Predictors of extubation failure and reintubation in newborn infants subjected to mechanical ventilation  

PubMed Central

Objective To identify risk factors for extubation failure and reintubation in newborn infants subjected to mechanical ventilation and to establish whether ventilation parameters and blood gas analysis behave as predictors of those outcomes. Methods Prospective study conducted at a neonatal intensive care unit from May to November 2011. A total of 176 infants of both genders subjected to mechanical ventilation were assessed after extubation. Extubation failure was defined as the need to resume mechanical ventilation within less than 72 hours. Reintubation was defined as the need to reintubate the infants any time after the first 72 hours. Results Based on the univariate analysis, the variables gestational age <28 weeks, birth weight <1,000g and low Apgar scores were associated with extubation failure and reintubation. Based on the multivariate analysis, the variables length of mechanical ventilation (days), potential of hydrogen (pH) and partial pressure of oxygen (pO2) remained associated with extubation failure, and the five-minute Apgar score and age at extubation were associated with reintubation. Conclusion Low five-minute Apgar scores, age at extubation, length of mechanical ventilation, acid-base disorders and hyperoxia exhibited associations with the investigated outcomes of extubation failure and reintubation.

Costa, Ana Cristina de Oliveira; Schettino, Renata de Carvalho; Ferreira, Sandra Clecencio

2014-01-01

103

Disability among Elderly Survivors of Mechanical Ventilation  

PubMed Central

Rationale: Studies of long-term functional outcomes of elderly survivors of mechanical ventilation (MV) are limited to local samples and biased retrospective, proxy-reported preadmission functional status. Objectives: To assess the impact on disability of hospitalization with MV, compared with hospitalization without MV, accounting for prospectively assessed prior functional status. Methods: Retrospective population-based longitudinal cohort study of Medicare beneficiaries age 65 and older enrolled in the Medicare Current Beneficiary Survey, 1996–2003. Measurements and Main Results: Premeasures and postmeasures of disability included mobility difficulty and weighted activities of daily living disability scores ranging from 0 (not disabled) to 100 (completely disabled) based on self-reported health and functional status collected 1 year apart. Among 54,771 person-years (PY) of observation over 7 calendar years of data, 42,890 PY involved no hospitalization, 11,347 PY involved a hospitalization without MV, and 534 PY included a hospitalization with MV. Mortality at 1 year was 8.9%, 23.9%, and 72.5%, respectively. The level of disability at the postassessment was substantially higher for a prototypical patient who survived after hospitalization with MV (adjusted activities of daily living disability score [95% confidence interval] 14.9 [12.2–17.7]; adjusted mobility difficulty score [95% confidence interval] 25.4 [22.4–28.4]) compared with an otherwise identical patient who survived hospitalization without MV (11.5 [11.1–11.9] and 22.3 [21.8–22.9]) or who was not hospitalized (8.0 [7.9–8.1] and 13.4 [13.3–13.6]). Conclusions: The greater marginal increase in disability among survivors of MV compared with survivors of hospitalization without MV is larger than would be predicted from prior functional status.

Barnato, Amber E.; Albert, Steven M.; Angus, Derek C.; Lave, Judith R.; Degenholtz, Howard B.

2011-01-01

104

Airway Strain during Mechanical Ventilation in an Intact Animal Model  

PubMed Central

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 ?m). 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.

Sinclair, Scott E.; Molthen, Robert C.; Haworth, Steve T.; Dawson, Christopher A.; Waters, Christopher M.

2007-01-01

105

A Prospective, Controlled Trial of a Protocol-based Strategy to Discontinue Mechanical Ventilation  

Microsoft Academic Search

Weaning protocols can improve outcomes, but their efficacy may vary with patient and staff characteristics. In this prospective, controlled trial, we compared protocol-based weaning to usual, physician- directed weaning in a closed medical intensive care unit (ICU) with high physician staffing levels and structured, system-based rounds. Adult patients requiring mechanical ventilation for more than 24 hours were assigned to usual

Jerry A. Krishnan; Dana Moore; Carey Robeson; Cynthia S. Rand; Henry E. Fessler

2004-01-01

106

Clinician discomfort with life support plans for mechanically ventilated patients  

Microsoft Academic Search

ObjectiveTo examine the incidence and predictors of clinician discomfort with life support plans for ICU patients.Design and settingProspective cohort in 13 medical-surgical ICUs in four countries.Patients657 mechanically ventilated adults expected to stay in ICU at least 72 h.Measurements and resultsDaily we documented the life support plan for mechanical ventilation, inotropes and dialysis, and clinician comfort with these plans. If uncomfortable, clinicians

Lauren Griffith; Deborah Cook; Steven Hanna; Graeme Rocker; Peter Sjokvist; Peter Dodek; John Marshall; Mitchell Levy; Joseph Varon; Simon Finfer; Roman Jaeschke; Lisa Buckingham; Gordon Guyatt

2004-01-01

107

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

PubMed

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 cmH?O) clearly exceeded those in patients with low PEEP (? 5 cmH?O). Additionally, a significant negative association existed between pneumonia duration and EBPs concentration. However, tidal volume was not related to EBPs concentration. PMID:24475230

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

2014-01-01

108

AssociaÁªo entre Ìndice de ventilaÁªo e tempo de ventilaÁªo mec‚nica em lactentes com bronquiolite viral aguda Association between ventilation index and time on mechanical ventilation in infants with acute viral bronchiolitis  

Microsoft Academic Search

Objective: To evaluate the association between time on mechanical ventilation and anthropometric, clinical and pulmonary function variables, measured early, in infants on invasive mechanical ventilation with acute respiratory failure due to viral bronchiolitis, and the temporal progression of variables with significant correlations. Methods: Twenty-nine infants admitted to the pediatric intensive care unit of UNICAMP university hospital were studied. Acute viral

Armando A. Almeida-Jœnior; Marcos T. N. da Silva; C. B. Almeida; Breno M. Nery; D. Ribeiro

2005-01-01

109

Low energy intake during the first week in an emergency intensive care unit is associated with reduced duration of mechanical ventilation in critically ill, underweight patients: a single-center retrospective chart review.  

PubMed

Background: Although nutrition support is essential in intensive care units, optimal energy intake remains unclear. Here, we assessed the influence of energy intake on outcomes of critically ill, underweight patients. Methods: A retrospective chart review was conducted in patients with body mass index (BMI) of <20.0 kg/m(2) in an emergency intensive care unit (EICU). Patients were categorized into 4 groups by initial Sequential Organ Failure Assessment score (I-SOFA) and average daily energy intake during the first week: group M-1, I-SOFA ?8 and <16 kcal/kg/d; group M-2, I-SOFA ?8 and ?16 kcal/kg/d; group S-1, I-SOFA >8 and <16 kcal/kg/d; and group S-2, I-SOFA >8 and ?16 kcal/kg/d. Results: The study included 51 patients with a median age of 69 years. No significant differences were noted in all-cause mortality and length of stay in the EICU and hospital between groups M-1 and M-2 or groups S-1 and S-2. The mechanical ventilation duration (MVD) was significantly shorter in group M-1 than M-2 (2.7 [1.0-5.7] vs 9.2 [4.2-17.4] days; P = .040) and in group S-1 than S-2 (3.1 [0.7-6.0] vs 8.8 [6.1-23.1] days; P = .006). The number of patients who underwent tracheostomy in hospital was significantly lower in group S-1 than in S-2 (20% vs 32%; P = .002). Multivariable analyses to adjust for confounders revealed that average energy intake during the first week in EICU was a significant factor independently associated with MVD but not with the requirement of tracheostomy. Conclusion: Reduced energy intake during the first week in EICU was associated with a reduced MVD in clinically ill patients with BMI <20.0 kg/m(2). PMID:24740496

Ichimaru, Satomi; Fujiwara, Hidetoshi; Amagai, Teruyoshi; Atsumi, Takahiro

2014-06-01

110

Newly identified precipitating factors in mechanical ventilation-induced brain damage: implications for treating ICU delirium.  

PubMed

Delirium is 1.5 to 4.1 times as likely in intensive care unit patients when they are mechanically ventilated. While progress in treatment has occurred, delirium is still a major problem in mechanically ventilated patients. Based on studies of a murine mechanical ventilation model, we summarize evidence here for a novel mechanism by which such ventilation can quickly initiate brain damage likely to cause cognitive deficits expressed as delirium. That mechanism consists of aberrant vagal sensory input driving sustained dopamine D2 receptor (D2R) signaling in the hippocampal formation, which induces apoptosis in that brain area within 90 min without causing hypoxia, oxidative stress, or inflammatory responses. This argues for minimizing the duration and tidal volumes of mechanical ventilation and for more effectively reducing sustained D2R signaling than achieved with haloperidol alone. The latter might be accomplished by reducing D2R cell surface expression and D2R-mediated Akt inhibition by elevating protein expression of dysbindin-1C. PMID:24852225

González-López, Adrián; Albaiceta, Guillermo M; Talbot, Konrad

2014-06-01

111

Actual performance of mechanical ventilators in ICU: a multicentric quality control study.  

PubMed

Even if the performance of a given ventilator has been evaluated in the laboratory under very well controlled conditions, inappropriate maintenance and lack of long-term stability and accuracy of the ventilator sensors may lead to ventilation errors in actual clinical practice. The aim of this study was to evaluate the actual performances of ventilators during clinical routines. A resistance (7.69 cmH(2)O/L/s) - elastance (100 mL/cmH(2)O) test lung equipped with pressure, flow, and oxygen concentration sensors was connected to the Y-piece of all the mechanical ventilators available for patients in four intensive care units (ICUs; n = 66). Ventilators were set to volume-controlled ventilation with tidal volume = 600 mL, respiratory rate = 20 breaths/minute, positive end-expiratory pressure (PEEP) = 8 cmH(2)O, and oxygen fraction = 0.5. The signals from the sensors were recorded to compute the ventilation parameters. The average ± standard deviation and range (min-max) of the ventilatory parameters were the following: inspired tidal volume = 607 ± 36 (530-723) mL, expired tidal volume = 608 ± 36 (530-728) mL, peak pressure = 20.8 ± 2.3 (17.2-25.9) cmH(2)O, respiratory rate = 20.09 ± 0.35 (19.5-21.6) breaths/minute, PEEP = 8.43 ± 0.57 (7.26-10.8) cmH(2)O, oxygen fraction = 0.49 ± 0.014 (0.41-0.53). The more error-prone parameters were the ones related to the measure of flow. In several cases, the actual delivered mechanical ventilation was considerably different from the set one, suggesting the need for improving quality control procedures for these machines. PMID:23293543

Govoni, Leonardo; Dellaca', Raffaele L; Peñuelas, Oscar; Bellani, Giacomo; Artigas, Antonio; Ferrer, Miquel; Navajas, Daniel; Pedotti, Antonio; Farré, Ramon

2012-01-01

112

Effective inhaled drug administration to mechanically ventilated patients.  

PubMed

Inhaled therapy is commonly employed in mechanically ventilated patients with chronic obstructive pulmonary disease or asthma. The efficacy of inhaled drugs is comparable to that achieved with systemic routes of administration, but the dose of drug required to achieve a therapeutic effect is generally much smaller. Moreover, limited systemic absorption of inhaled drugs minimises systemic side effects. Aerosol administration to ventilated patients differs from that in ambulatory patients in several respects. Optimal techniques for using pressurised metered-dose inhalers and nebulisers in ventilator circuits have been developed. With these techniques, the efficiency of inhaled drug delivery in mechanically ventilated patients is now comparable to that in ambulatory patients. Pressurised metered-dose inhalers are chiefly used to deliver bronchodilator and corticosteroid aerosols, and are more efficient and convenient to use than nebulisers for routine therapy in ventilated patients. However, nebulisers are more versatile and are employed to generate aerosols of bronchodilators, corticosteroids, antibiotics, prostaglandins, surfactant and mucolytic agents. Improvements in drug formulations and the design and efficiency of aerosol generating devices have led to increasing application of inhaled therapies in mechanically ventilated patients. PMID:17184162

Dhand, Rajiv; Mercier, Emmanuelle

2007-01-01

113

Cardiac output estimation using pulmonary mechanics in mechanically ventilated patients.  

PubMed

The application of positive end expiratory pressure (PEEP) in mechanically ventilated (MV) patients with acute respiratory distress syndrome (ARDS) decreases cardiac output (CO). Accurate measurement of CO is highly invasive and is not ideal for all MV critically ill patients. However, the link between the PEEP used in MV, and CO provides an opportunity to assess CO via MV therapy and other existing measurements, creating a CO measure without further invasiveness.This paper examines combining models of diffusion resistance and lung mechanics, to help predict CO changes due to PEEP. The CO estimator uses an initial measurement of pulmonary shunt, and estimations of shunt changes due to PEEP to predict CO at different levels of PEEP. Inputs to the cardiac model are the PV loops from the ventilator, as well as the oxygen saturation values using known respiratory inspired oxygen content. The outputs are estimates of pulmonary shunt and CO changes due to changes in applied PEEP. Data from two published studies are used to assess and initially validate this model.The model shows the effect on oxygenation due to decreased CO and decreased shunt, resulting from increased PEEP. It concludes that there is a trade off on oxygenation parameters. More clinically importantly, the model also examines how the rate of CO drop with increased PEEP can be used as a method to determine optimal PEEP, which may be used to optimise MV therapy with respect to the gas exchange achieved, as well as accounting for the impact on the cardiovascular system and its management. PMID:21108836

Sundaresan, Ashwath; Chase, J Geoffrey; Hann, Christopher E; Shaw, Geoffrey M

2010-01-01

114

How outcomes are defined in clinical trials of mechanically ventilated adults and children.  

PubMed

Systematic reviews have considerable potential to provide evidence-based data to aid clinical decision-making. However, there is growing recognition that trials involving mechanical ventilation lack consistency in the definition and measurement of ventilation outcomes, creating difficulties in combining data for meta-analyses. To address the inconsistency in outcome definitions, international standards for trial registration and clinical trial protocols published recommendations, effectively setting the "gold standard" for reporting trial outcomes. In this Critical Care Perspective, we review the problems resulting from inconsistent outcome definitions and inconsistent reporting of outcomes (outcome sets). We present data highlighting the variability of the most commonly reported ventilation outcome definitions. Ventilation outcomes reported in trials over the last 6 years typically fall into four domains: measures of ventilator dependence; adverse outcomes; mortality; and resource use. We highlight the need, first, for agreement on outcome definitions and, second, for a minimum core outcome set for trials involving mechanical ventilation. A minimum core outcome set would not restrict trialists from measuring additional outcomes, but would overcome problems of variability in outcome selection, measurement, and reporting, thereby enhancing comparisons across trials. PMID:24512505

Blackwood, Bronagh; Clarke, Mike; McAuley, Danny F; McGuigan, Peter J; Marshall, John C; Rose, Louise

2014-04-15

115

Ventilator Dependent Unit Demonstration. Outcome Evaluation and Assessment of Post Acute Care.  

National Technical Information Service (NTIS)

The report presents the findings from the outcome evaluation and post-acute care analysis of the Ventilator Dependent Unit Payment Demonstration, sponsored by the Health Care Finance Administration (HCFA). The main purpose of the Demonstration is to evalu...

D. C. Stapleton S. J. Kaplan

1996-01-01

116

Trend of Maximal Inspiratory Pressure in Mechanically Ventilated Patients: Predictors  

PubMed Central

INTRODUCTION It is known that mechanical ventilation and many of its features may affect the evolution of inspiratory muscle strength during ventilation. However, this evolution has not been described, nor have its predictors been studied. In addition, a probable parallel between inspiratory and limb muscle strength evolution has not been investigated. OBJECTIVE To describe the variation over time of maximal inspiratory pressure during mechanical ventilation and its predictors. We also studied the possible relationship between the evolution of maximal inspiratory pressure and limb muscle strength. METHODS A prospective observational study was performed in consecutive patients submitted to mechanical ventilation for > 72 hours. The maximal inspiratory pressure trend was evaluated by the linear regression of the daily maximal inspiratory pressure and a logistic regression analysis was used to look for independent maximal inspiratory pressure trend predictors. Limb muscle strength was evaluated using the Medical Research Council score. RESULTS One hundred and sixteen patients were studied, forty-four of whom (37.9%) presented a decrease in maximal inspiratory pressure over time. The members of the group in which maximal inspiratory pressure decreased underwent deeper sedation, spent less time in pressure support ventilation and were extubated less frequently. The only independent predictor of the maximal inspiratory pressure trend was the level of sedation (OR=1.55, 95% CI 1.003 – 2.408; p = 0.049). There was no relationship between the maximal inspiratory pressure trend and limb muscle strength. CONCLUSIONS Around forty percent of the mechanically ventilated patients had a decreased maximal inspiratory pressure during mechanical ventilation, which was independently associated with deeper levels of sedation. There was no relationship between the evolution of maximal inspiratory pressure and the muscular strength of the limb.

Caruso, Pedro; Carnieli, Denise Simao; Kagohara, Keila Harue; Anciaes, Adriana; Segarra, Jacqueline Santos; Deheinzelin, Daniel

2008-01-01

117

[Chronic respiratory failure: the role of home mechanical ventilation].  

PubMed

While negative pressure ventilation using cuirass respirators or iron-lung machines was prevailing in the first part of the 20th century, the polio epidemic in Copenhagen 1952 marks the turning point at which positive pressure ventilation following tracheotomy was started. Furthermore, following the introduction of facial masks and starting 1985 in Germany non-invasive positive pressure ventilation has meanwhile been developed as a routine procedure for the long-term treatment of patients with chronic ventilatory failure today. The current article provides an overview of these developments and also outlines the role of two particular national societies: "Deutsche Gesellschaft für Pneumologie und Beatmungsmedizin (DGP) e.?V." (German Medical Association of Pneumology and Ventilatory Support) and "Deutsche Interdisziplinäre Gesellschaft für außerklinische Beatmung (DIGAB) e.?V." (German Interdisciplinary Society for Home Mechanical Ventilation). PMID:20827646

Windisch, W

2010-09-01

118

Sleep quality in mechanically ventilated patients: comparison between NAVA and PSV modes  

PubMed Central

Background Mechanical ventilation seems to occupy a major source in alteration in the quality and quantity of sleep among patients in intensive care. Quality of sleep is negatively affected with frequent patient-ventilator asynchronies and more specifically with modes of ventilation. The quality of sleep among ventilated patients seems to be related in part to the alteration between the capacities of the ventilator to meet patient demand. The objective of this study was to compare the impact of two modes of ventilation and patient-ventilator interaction on sleep architecture. Methods Prospective, comparative crossover study in 14 conscious, nonsedated, mechanically ventilated adults, during weaning in a university hospital medical intensive care unit. Patients were successively ventilated in a random ordered cross-over sequence with neurally adjusted ventilatory assist (NAVA) and pressure support ventilation (PSV). Sleep polysomnography was performed during four 4-hour periods, two with each mode in random order. Results The tracings of the flow, airway pressure, and electrical activity of the diaphragm were used to diagnose central apneas and ineffective efforts. The main abnormalities were a low percentage of rapid eye movement (REM) sleep, for a median (25th-75th percentiles) of 11.5% (range, 8-20%) of total sleep, and a highly fragmented sleep with 25 arousals and awakenings per hour of sleep. Proportions of REM sleep duration were different in the two ventilatory modes (4.5% (range, 3-11%) in PSV and 16.5% (range, 13-29%) during NAVA (p = 0.001)), as well as the fragmentation index, with 40 ± 20 arousals and awakenings per hour in PSV and 16 ± 9 during NAVA (p = 0.001). There were large differences in ineffective efforts (24 ± 23 per hour of sleep in PSV, and 0 during NAVA) and episodes of central apnea (10.5 ± 11 in PSV vs. 0 during NAVA). Minute ventilation was similar in both modes. Conclusions NAVA improves the quality of sleep over PSV in terms of REM sleep, fragmentation index, and ineffective efforts in a nonsedated adult population.

2011-01-01

119

Mechanical Ventilation for Comatose Patients with Inoperative Acute Intracerebral Hemorrhage: Possible Futility of Treatment  

PubMed Central

Background Comatose patients with acute intracerebral hemorrhage (ICH) diagnosed as inoperative due to their severe comorbidity will be treated differently between countries. In certain countries including Japan, aggressive medical care may be performed according to the patients' family requests although the effects on the outcome are obscure. For respiratory distress in comatose patients with inoperative acute ICH, the role of mechanical ventilation on the outcome is unknown. We speculated that the efficacy of a ventilator in such a specific condition is limited and possibly futile. Methods We retrospectively evaluated the in-hospital mortality and further outcome of 65 comatose patients with inoperative ICH. Among the patients, 56 manifested respiratory distress, and the effect of the ventilator was evaluated by comparing the patients treated with and without the ventilator. Results The in-hospital mortality was calculated as 80%. A statistically significant parameter affecting the mortality independently was the motor subset on the Glasgow Coma Scale (P?=?0.015). Among the patients who manifested respiratory distress, 7.7% of patients treated with a ventilator and 14.0% of patients not treated with a ventilator survived; an outcome is not significantly different. The mean survival duration of patients treated with a ventilator was significantly longer than the mean survival duration of patients not treated with a ventilator (P?=?0.021). Among the surviving 13 patients, 7 patients died 5 to 29 months after onset without significant consciousness recovery. Another 6 patients suffered continuous disablement due to prolonged severe consciousness disturbances. Conclusion The current results indicate that treating comatose patients resulting from inoperative acute ICH may be futile. In particular, treating these patients with a ventilator only has the effect of prolonging unresponsive life, and the treatment may be criticized from the perspective of the appropriate use of public medical resources.

Fukuhara, Toru; Aoi, Mizuho; Namba, Yoichiro

2014-01-01

120

The efficacy of eye care for ventilated patients: outline of an experimental comparative research pilot study.  

PubMed

The aim in this study was to investigate the efficacy of eye care given to mechanically ventilated and unconscious patients in an intensive care unit; and to answer the research question: "Is eye surface integrity maintained after the application of a "Geliperm" dressing to the closed eye of a ventilated patient?' Six patients formed the sample group. In each patient one eye received standard eye care, forming the control group, and the other eye received a 'geliperm' dressing, forming the treatment group. Tear production, using the Schirmer test, and the degree of eye surface staining by rose bengal were used as the measurement indicators. As a pilot study this project was primarily concerned with establishing a sound methodology for further enquiry. There were some difficulties in validating the degree of rose bengal staining; no statistically significant difference could be demonstrated between outcomes of the two forms of eye care after a 24-hour test period, with a P = 0.05 significance level, using the Mann-Whitney-U test. It should be noted, however, that the sample size was too small to measure a statistically significant change or its absence, in either the treatment or control eye between pre- and post-test results, with the same significance level, and using the Wilcoxon signed rank test. This study does provide evidence to support the need for eye care for critically ill patients. The methodology may offer a way forward for future investigation in the search for optimal eye surface preservation. PMID:8696019

Laight, S E

1996-02-01

121

Cerebral Arterial Air Embolism Associated with Mechanical Ventilation and Deep Tracheal Aspiration  

PubMed Central

Arterial air embolism associated with pulmonary barotrauma has been considered a rare but a well-known complication of mechanical ventilation. A 65-year-old man, who had subarachnoid hemorrhage with Glasgow coma scale of 8, was admitted to intensive care unit and ventilated with the help of mechanical ventilator. Due to the excessive secretions, deep tracheal aspirations were made frequently. GCS decreased from 8–10 to 4-5, and the patient was reevaluated with cranial CT scan. In CT scan, air embolism was detected in the cerebral arteries. The patient deteriorated and spontaneous respiratory activity lost just after the CT investigation. Thirty minutes later cardiac arrest appeared. Despite the resuscitation, the patient died. We suggest that pneumonia and frequent tracheal aspirations are predisposing factors for cerebral vascular air embolism.

Gursoy, S.; Duger, C.; Kaygusuz, K.; Ozdemir Kol, I.; Gurelik, B.; Mimaroglu, C.

2012-01-01

122

We do not need mechanical ventilation any more.  

PubMed

Mechanical ventilation is a lifesaving treatment delivered to patients with a wide spectrum of medical and surgical diseases. However, significant limitations of the clinical application of mechanical ventilation in current practice have emerged, prompting the definition of novel therapeutic perspectives, especially concerning the prevention and treatment of acute respiratory failure. In the past few decades, there has been a consistent scientific and technologic effort to develop alternative strategies to avoid the need for mechanical ventilation. In particular, several studies have explored the feasibility and efficacy of extracorporeal oxygenation and carbon dioxide removal. Furthermore, promising results on the prevention of the occurrence of severe acute respiratory failure have been provided by clinical studies on the noninvasive application of continuous positive airway pressure as well as by experimental investigations in basic science. Therefore, further development in this direction will occur only with a permanent integration and exchange of knowledge among industry, clinicians, and scientific investigators. PMID:21164397

Del Sorbo, Lorenzo; Ranieri, V Marco

2010-10-01

123

[Interface type helmet non-invasive mechanical ventilation].  

PubMed

Non-invasive mechanical ventilation is a technique that has ceased to be exclusively used in intensive medicine services to form part of the armamentarium of emergency and critical services, assuming an adaptation to this procedure by the nursing staff whose participation is crucial to achieve the triumph of technique. Composed basically of a mechanical ventilator and a mask (interface) which is interposed between the patient and the fan without invading the airway, requires the collaboration of the patient unlike conventional mechanical ventilation and, initially, a longer time of dedication of the nurse. Interfaces models and the evolution of the same to achieve the effects desired with good tolerance by the patient came to the development of the Helmet, a device in the form of diving, well tolerated by the patient, allowing the use of high pressure for alveolar recruitment, but that, by design, has connotations that must be known before use. PMID:24547633

Migallón Buitrago, M Elvira; García-Velasco Sánchez-Morago, Santiago; Ramírez de Orol, Miguel Angel; Puyana Manrique de Lara, M del Carmen

2013-12-01

124

Propofol is associated with favorable outcomes compared with benzodiazepines in ventilated intensive care unit patients.  

PubMed

Rationale: Mechanically ventilated intensive care unit (ICU) patients are frequently managed using a continuous-infusion sedative. Although recent guidelines suggest avoiding benzodiazepines for sedation, this class of drugs is still widely used. There are limited data comparing sedative agents in terms of clinical outcomes in an ICU setting. Objectives: Comparison of propofol to midazolam and lorazepam in adult ICU patients. Methods: Data were obtained from a multicenter ICU database (2003-2009). Patient selection criteria included age greater than or equal to 18 years, single ICU admission with single ventilation event (>48 h), and treatment with continuously infused sedation (propofol, midazolam, or lorazepam). Propensity score analysis (1:1) was used and mortality measured. Cumulative incidence and competing risk methodology were used to examine time to ICU discharge and ventilator removal. Measurements and Main Results: There were 2,250 propofol-midazolam and 1,054 propofol-lorazepam matched patients. Hospital mortality was statistically lower in propofol-treated patients as compared with midazolam- or lorazepam-treated patients (risk ratio, 0.76; 95% confidence interval [CI], 0.69-0.82 and risk ratio, 0.78; 95% CI, 0.68-0.89, respectively). Competing risk analysis for 28-day ICU time period showed that propofol-treated patients had a statistically higher probability for ICU discharge (78.9% vs. 69.5%; 79.2% vs. 71.9%; P < 0.001) and earlier removal from the ventilator (84.4% vs. 75.1%; 84.3% vs. 78.8%; P < 0.001) when compared with midazolam- and lorazepam-treated patients, respectively. Conclusions: In this large, propensity-matched ICU population, patients treated with propofol had a reduced risk of mortality and had both an increased likelihood of earlier ICU discharge and earlier discontinuation of mechanical ventilation. PMID:24720509

Lonardo, Nick W; Mone, Mary C; Nirula, Raminder; Kimball, Edward J; Ludwig, Kyle; Zhou, Xi; Sauer, Brian C; Nechodom, Kevin; Teng, Chiachen; Barton, Richard G

2014-06-01

125

Multicenter Evaluation of a Novel Surveillance Paradigm for Complications of Mechanical Ventilation  

PubMed Central

Background Ventilator-associated pneumonia (VAP) surveillance is time consuming, subjective, inaccurate, and inconsistently predicts outcomes. Shifting surveillance from pneumonia in particular to complications in general might circumvent the VAP definition's subjectivity and inaccuracy, facilitate electronic assessment, make interfacility comparisons more meaningful, and encourage broader prevention strategies. We therefore evaluated a novel surveillance paradigm for ventilator-associated complications (VAC) defined by sustained increases in patients' ventilator settings after a period of stable or decreasing support. Methods We assessed 600 mechanically ventilated medical and surgical patients from three hospitals. Each hospital contributed 100 randomly selected patients ventilated 2–7 days and 100 patients ventilated >7 days. All patients were independently assessed for VAP and for VAC. We compared incidence-density, duration of mechanical ventilation, intensive care and hospital lengths of stay, hospital mortality, and time required for surveillance for VAP and for VAC. A subset of patients with VAP and VAC were independently reviewed by a physician to determine possible etiology. Results Of 597 evaluable patients, 9.3% had VAP (8.8 per 1,000 ventilator days) and 23% had VAC (21.2 per 1,000 ventilator days). Compared to matched controls, both VAP and VAC prolonged days to extubation (5.8, 95% CI 4.2–8.0 and 6.0, 95% CI 5.1–7.1 respectively), days to intensive care discharge (5.7, 95% CI 4.2–7.7 and 5.0, 95% CI 4.1–5.9), and days to hospital discharge (4.7, 95% CI 2.6–7.5 and 3.0, 95% CI 2.1–4.0). VAC was associated with increased mortality (OR 2.0, 95% CI 1.3–3.2) but VAP was not (OR 1.1, 95% CI 0.5–2.4). VAC assessment was faster (mean 1.8 versus 39 minutes per patient). Both VAP and VAC events were predominantly attributable to pneumonia, pulmonary edema, ARDS, and atelectasis. Conclusions Screening ventilator settings for VAC captures a similar set of complications to traditional VAP surveillance but is faster, more objective, and a superior predictor of outcomes.

Klompas, Michael; Khan, Yosef; Kleinman, Kenneth; Evans, R. Scott; Lloyd, James F.; Stevenson, Kurt; Samore, Matthew; Platt, Richard

2011-01-01

126

Effects of increasing compliance with minimal sedation on duration of mechanical ventilation: a quality improvement intervention  

PubMed Central

Introduction In the past two decades, healthcare adopted industrial strategies for process measurement and control. In the industry model, care is taken to avoid minimal deviations from a standard. In healthcare there is scarce data to support that a similar strategy can lead to better outcomes. Briefly, when compliance is high, further attempts to improve uptake of a process are seldom made. Our intensive care unit (ICU) improved the compliance with minimizing sedation from a high baseline of 80.4% (95% CI: 66.9 to 90.2) to 96.2% (95% CI: 95.2 to 97.0) 12 months after a quality improvement initiative. We sought to measure whether this minute improvement in compliance led to a reduction in duration of mechanical ventilation. Methods We collected data on compliance with the process during 12 months. A trained data collector abstracted data from charts every other day. Our database contains data for length of mechanical ventilation, mortality, type of admission, and acute physiology and chronic health evaluation (APACHE) II scores for the 12 months before and after the process improvement. To control for secular trends we used an interrupted-time series with adjustment for auto-correlation. We calculated the expected length of mechanical ventilation on each month by the end of the intervention period, and calculated the fitted value for the post-intervention months. Results We included 1556 patients. There was an immediate effect of the intervention (regression coefficient = -0.129, P value < 0.001) and the secular trend was a determinant of length of mechanical ventilation (regression coefficient = 0.010, P value = 0.004). The trend post-intervention was not significant (regression coefficient = 0.004, P value = 0.380). The relative change in the length of mechanical ventilation was 14.5% (IQR 13.8% to 15.8%) and the total expected decrease in mechanical ventilation days was 502.7 days (95% CI 300.9 to 729.1) over one year. Conclusions In a system already working at high levels of compliance, outcomes can still be improved. Our intervention was successful in reducing the length of mechanical ventilation. ICUs should have a process of quality assurance in place to provide constant monitoring of key quality of care processes and correct deviations from the proposed standard.

2012-01-01

127

Both High Level Pressure Support Ventilation and Controlled Mechanical Ventilation Induce Diaphragm Dysfunction and Atrophy  

PubMed Central

Rationale Previous workers have demonstrated that controlled mechanical ventilation (CMV) results in diaphragm inactivity and elicits a rapid development of diaphragm weakness due to both contractile dysfunction and fiber atrophy. Limited data exist regarding the impact of pressure support ventilation (PSV),a commonly used mode of mechanical ventilation--that permits partial mechanical activity of the diaphragm—on diaphragm structure and function. Objectives We carried out the present study to test the hypothesis that high level PSV decreases the diaphragm pathology associated with CMV. Methods Sprague-Dawley rats were randomly assigned to one of the following five groups:1) control (no mechanical ventilation); 2) 12 hours of CMV (12CMV); 3) 18 hours of CMV (18CMV); 4) 12 hours of PSV (12PSV); or 5) 18 hours of PSV (18PSV). Measurements and main results We carried out the following measurements on diaphragm specimens: 4-hydroxynonenal (HNE)—a marker of oxidative stress, active caspase-3 (casp-3),active calpain-1 (calp-1), fiber type cross-sectional area (CSA), and specific force (sp F). Compared to control, both 12PSV and 18PSV promoted a significant decrement in diaphragmatic specific force production, but to a lesser degree than 12CMV and 18CMV. Further, 12CMV, 18PSV, and 18CMV resulted in significant atrophy in all diaphragm fiber types, as well as significant increases in a biomarker of oxidative stress (4-HNE) and increased proteolytic activity (20S proteasome, calpain-1, and caspase-3). Further, while no inspiratory effort occurs during CMV, it was observed that PSV resulted in large decrement, ~96%, in inspiratory effort compared to spontaneous breathing animals. Conclusion High levels of prolonged PSV promotes diaphragmatic atrophy and contractile dysfunction. Further, similar to CMV, PSV-induced diaphragmatic atrophy and weakness is associated with both diaphragmatic oxidative stress and protease activation. .

Hudson, Matthew B.; Smuder, Ashley J.; Nelson, W. Bradley; Bruells, Christian S.; Levine, Sanford; Powers, Scott K.

2011-01-01

128

Interval neurophysiological changes in non septic critically ill mechanically ventilated patients.  

PubMed

Peripheral nerve changes in critically ill patients are common, sepsis being the most important risk factor. The aim of our study is to investigate interval neurophysiological changes in non septic mechanically ventilated critically ill patients, a group who has not been the focus of previous studies. Consecutive non septic mechanically ventilated critically ill patients were included. Baseline nerve conduction studies (NCS) were done within 3 days of intensive care unit admission, and 48 hours after the initiation of mechanical ventilation, and were followed up 7-8 days later. Sural and ulnar sensory, and median and peroneal motor nerves were tested. Nine patients were studied, five (56%) showed significant changes in their NCS compared to baseline. The peroneal and sural nerve amplitudes significantly dropped in all of the five affected patients, with drop of those of the median motor nerves in two, and ulnar sensory nerves in three patients. In conclusion, interval changes in peripheral nerves can exist in critically ill mechanically ventilated non septic patients. The pattern is similar to critically ill patients with sepsis. Theories of possible pathophysiology of critical illness neuropathy should not merely depend on the presence of sepsis as a trigger and other mechanisms should be investigated. PMID:22854770

El-Salem, Khalid; Khassawneh, Basheer; Alrefai, Ali; Dwairy, Abdel Raheem; Rawashdeh, Sukaina

2012-08-01

129

[Respiratory failure in mitochondrial myopathy treated with noninvasive mechanical ventilation].  

PubMed

Young man suffering from mitochondrial myopathy was admitted to our Institute due to severe hypercapnic respiratory failure. Noninvasive mechanical ventilation (NWM) during sleep using nasal mask was instituted with positive results. Diurnal blood gases breathing air also ameliorated suggesting improvement of respiratory muscles function. PMID:10391964

Biele?, P; Sliwi?ski, P; Kami?ski, D; Zieli?ski, J

1998-01-01

130

Gastric acidity and duodenogastric reflux during nasojejunal tube feeding in mechanically ventilated patients  

Microsoft Academic Search

Objective: In order to prevent gastric microbial overgrowth, which may complicate nasogastric feeding, administration of nutrients\\u000a more distally into the gut has been advocated in intensive care patients, as it offers the advantage of keeping the stomach\\u000a empty and acid. In this study, we assessed the impact of jejunal feeding upon gastic pH in a group of mechanically ventilated,\\u000a critically

A. Dive; I. Michel; L. Galanti; J. Jamart; T. Vander Borght; E. Installé

1999-01-01

131

Gastric emptying in mechanically ventilated critically ill patients: effect of neuromuscular blocking agent  

Microsoft Academic Search

ObjectiveTo assess gastrointestinal function in critically ill patients receiving muscle relaxant and to test clinical tolerance to enteral nutrition.Design and settingProspective study in an intensive care unit.Patients20 critically ill patients requiring sedation with muscle relaxant to obtain adequate mechanical ventilation.Measurements and resultsPatients were randomly selected to receive infusions of opioid sedation during the first session (session 1) and the same

Fabienne Tamion; Karine Hamelin; Annie Duflo; Christophe Girault; Jean-Christophe Richard; Guy Bonmarchand

2003-01-01

132

Ventilator-associated pneumonia in a tertiary care intensive care unit: Analysis of incidence, risk factors and mortality  

PubMed Central

Background: Ventilator-associated pneumonia (VAP) is the most common nosocomial infection diagnosed in the intensive care unit (ICU) and in spite of advances in diagnostic techniques and management it remains a common cause of hospital morbidity and mortality. Objective: The primary objective of the following study is to determine the incidence, various risk factors and attributable mortality associated with VAP and secondary objective is to identify the various bacterial pathogens causing VAP in the ICU. Materials and Methods: This prospective observational study was carried out over a period of 1 year. VAP was diagnosed using the clinical pulmonary infection score. Endotracheal aspirate (ETA) and bronchoalveolar lavage (BAL) samples of suspected cases of VAP were collected from ICU patients and processed as per standard protocols. Statistical Analysis: Fisher's exact test was applied when to compare two or more set of variables were compared. Results: The incidence of VAP in our study was 57.14% and the incidence density of VAP was 31.7/1000 ventilator days. Trauma was the commonest underlying condition associated with VAP. The incidence of VAP increased as the duration of mechanical ventilation increased and there was a total agreement in bacteriology between semi-quantitative ETAs and BALs in our study. The overall mortality associated with VAP was observed to be 48.33%. Conclusions: The incidence of VAP was 57.14%. Study showed that the incidence of VAP is directly proportional to the duration of mechanical ventilation. The most common pathogens causing VAP were Acinetobacter spp. and Pseudomonas aeruginosa and were associated with a high fatality rate.

Ranjan, Neelima; Chaudhary, Uma; Chaudhry, Dhruva; Ranjan, K. P.

2014-01-01

133

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

PubMed Central

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.

2012-01-01

134

Negative pressure ventilation in pediatric critical care setting  

Microsoft Academic Search

Invasive ventilation is associated with both pulmonary and non-pulmonary complications. There has been a renewed interest\\u000a in the use of negative pressure ventilation (NPV) for various medical conditions to minimise the complications associated\\u000a with positive pressure ventilation. The routine use of NPV in an ICU setting still requires further studies and research.\\u000a In this article, the authors review the clinical

Akash Deep; Claudine De Munter; Ajay Desai

2007-01-01

135

Absolute electrical impedance tomography (aEIT) guided ventilation therapy in critical care patients: simulations and future trends.  

PubMed

Thoracic electrical impedance tomography (EIT) is a noninvasive, radiation-free monitoring technique whose aim is to reconstruct a cross-sectional image of the internal spatial distribution of conductivity from electrical measurements made by injecting small alternating currents via an electrode array placed on the surface of the thorax. The purpose of this paper is to discuss the fundamentals of EIT and demonstrate the principles of mechanical ventilation, lung recruitment, and EIT imaging on a comprehensive physiological model, which combines a model of respiratory mechanics, a model of the human lung absolute resistivity as a function of air content, and a 2-D finite-element mesh of the thorax to simulate EIT image reconstruction during mechanical ventilation. The overall model gives a good understanding of respiratory physiology and EIT monitoring techniques in mechanically ventilated patients. The model proposed here was able to reproduce consistent images of ventilation distribution in simulated acutely injured and collapsed lung conditions. A new advisory system architecture integrating a previously developed data-driven physiological model for continuous and noninvasive predictions of blood gas parameters with the regional lung function data/information generated from absolute EIT (aEIT) is proposed for monitoring and ventilator therapy management of critical care patients. PMID:19906599

Denaï, Mouloud A; Mahfouf, Mahdi; Mohamad-Samuri, Suzani; Panoutsos, George; Brown, Brian H; Mills, Gary H

2010-05-01

136

Mechanical Ventilation in Hypobaric Atmosphere - Aeromedical Transport of Critically Ill Patients.  

National Technical Information Service (NTIS)

Mechanical ventilation is used in most of the aeroevacuations of critically ill patients. Patients and mechanical ventilators suffer from variations in the environmental pressure, partial pressure of oxygen, humidity, luminosity, accelerations and vibrati...

A. Hernandez Abadia de Barbara A. Gil Heras J. A. Lopez Lopez F. Rios Tejada

2004-01-01

137

Mechanical exsufflation, noninvasive ventilation, and new strategies for pulmonary rehabilitation and sleep disordered breathing.  

PubMed Central

Manual and mechanical exsufflation are important but underutilized ways to clear airway secretions. These methods are especially useful when used in concert with noninvasive intermittent positive airway pressure ventilatory assistance to facilitate extubation and ventilator weaning. This can be used as much as 24 hours a day as an alternative to tracheostomy ventilation or body ventilator use for patients with paralytic restrictive ventilatory insufficiency. These techniques expedite community management of ventilator assisted individuals by avoiding tracheostomy and need for invasive suctioning and ongoing wound care. For these techniques to be effective and to prevent further suppression of ventilatory drive, supplemental oxygen administration must be avoided unless pO2 is less than 60 mm Hg despite normalization of pCO2. Custom molded interfaces for the delivery of noninvasive intermittent positive airway pressure ventilatory assistance can also be used to facilitate the delivery of variable inspiratory expiratory positive airway pressure for patients with obstructive sleep apnea. Noninvasive intermittent positive airway pressure ventilatory assistance or body ventilator use can rest the respiratory muscles of patients with advanced chronic obstructive pulmonary disease. This and pulmonary rehabilitation programs geared to exercise reconditioning are therapeutic options that significantly improve the quality of life of these patients. For both paralytic restrictive and obstructive pulmonary patients, these techniques decrease cost and frequency of hospitalizations. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6

Bach, J. R.

1992-01-01

138

Breathing cardiovascular variability and baroreflex in mechanically ventilated patients.  

PubMed

Heart rate and blood pressure variations during spontaneous ventilation are related to the negative airway pressure during inspiration. Inspiratory airway pressure is positive during mechanical ventilation, suggesting that reversal of the normal baroreflex-mediated pattern of variability may occur. We investigated heart rate and blood pressure variability and baroreflex sensitivity in 17 mechanically ventilated patients. ECG (RR intervals), invasive systolic blood pressure (SBP), and respiratory flow signals were recorded. High-frequency (HF) amplitude of RR and SBP time series and HF phase differences between RR, SBP, and ventilatory signals were continuously computed by Complex DeModulation (CDM). Cross-spectral analysis was used to assess the coherence and the gain functions between RR and SBP, yielding baroreflex sensitivity indices. The HF phase difference between SBP and ventilatory signals was nearly constant in all patients with inversion of SBP variability during the ventilator cycle compared with cycling with negative inspiratory pressure to replicate spontaneous breathing. In 12 patients (group 1), the phase difference between RR and ventilatory signals changed over time and the HF-RR amplitude varied. In the remaining five patients (group 2), RR-ventilatory signal phase and HF-RR amplitude showed little change; however, only one of these patients exhibited a RR-ventilatory signal phase difference mimicking the normal pattern of respiratory sinus arrhythmia. Spectral coherence between RR and SBP was lower in the group with phase difference changes. Positive pressure ventilation exerts mainly a mechanical effect on SBP, whereas its influence on HR variability seems more complex, suggesting a role for neural influences. PMID:18922962

Van de Louw, Andry; Médigue, Claire; Papelier, Yves; Cottin, François

2008-12-01

139

Ventilation distribution and chest wall mechanics in microgravity  

NASA Technical Reports Server (NTRS)

The effect of gravity on lung ventilation distribution and the mechanisms of the chest wall were investigated. The following tests were performed with the respiratory monitoring system of the Anthorack, flown onboard Spacelab D2 mission: single breath washout (SBW), multiple breath washout (MBW) and argon rebreathing (ARB). In order to study chest wall mechanisms in microgravity, a respiratory inductive plethysmograph was used. The SBW tests did not reach statistical significance, while the ARB tests showed that gravity independent inhomogeneity of specific ventilation is larger than gravity dependent inhomogeneity. In which concerns the chest wall mechanisms, the analysis on the four astronauts during the normal respirations of the relaxation maneuver showed a 40 percent increase on the abdominal contribution to respiration.

Paiva, M.; Wantier, M.; Verbanck, S.; Engel, L. A.; Prisk, G. K.; Guy, H. J. B.; West, J. B.

1997-01-01

140

Weaning Preterm Infants from Mechanical Ventilation  

Microsoft Academic Search

Mechanical ventilatory support is required by a large number of neonates in respiratory failure. However, its use in preterm infants is frequently associated with acute complications and long-term respiratory sequelae. Therefore, it is recommended to avoid or limit the exposure to ventilatory support. This is a review of existing practices and novel strategies to achieve weaning of ventilatory support in

Eduardo Bancalari; Nelson Claure

2008-01-01

141

NATURAL HISTORY OF DENTAL PLAQUE ACCUMULATION IN MECHANICALLY VENTILATED ADULTS: A DESCRIPTIVE CORRELATIONAL STUDY  

PubMed Central

Summary Objective The purpose of this study was to describe the pattern of dental plaque accumulation in mechanically ventilated adults. Accumulation of dental plaque and bacterial colonization of the oropharynx is associated with a number of systemic diseases including ventilator associated pneumonia. Research Methodology/Design Data were collected from mechanically ventilated critically ill adults (n=137), enrolled within 24 hours of intubation. Dental plaque, counts of decayed, missing and filled teeth and systemic antibiotic use was assessed on study days 1, 3, 5 and 7. Dental plaque averages per study day, tooth type and tooth location were analyzed. Setting Medical Respiratory, Surgical Trauma and Neuroscience ICU’s of a large tertiary care center in the southeast United States. Results Plaque: All surfaces > 60% plaque coverage from day 1 to day 7; Molars and Premolars contained greatest plaque average >70%. Systemic antibiotic use on day 1 had no significant effect on plaque accumulation on day 3 (p=0.73). Conclusions Patients arrive in critical care units with preexisting oral hygiene issues. Dental plaque tends to accumulate in the posterior teeth (molars and premolars) that may be hard for nurses to visualize and reach; this problem may be exacerbated by endotracheal tubes and other equipment. Knowing accumulation trends of plaque will guide the development of effective oral care protocols.

Jones, Deborah J.; Munro, Cindy L.; Grap, Mary Jo

2011-01-01

142

Tilt Table Practice Improved Ventilation in a Patient with Prolonged Artificial Ventilation Support in Intensive Care Unit  

PubMed Central

Patients who are on prolonged ventilator support in critical care unit present wide variety of complications, which range from reduction in oxygen uptake to various musculoskeletal impairments. Early mobilization and rehabilitation are encouraged to manage these complications effectively. Use of tilt table to motivate early mobilization in the intensive care unit for ventilator practices is not a usual practice. However, this new technique has attracted involvements of clinicians and therapists for its therapeutic benefits to the patient. Herein we describe a case of a seventy eight-year-old male patient who suffered Motor car accident, and was on ventilator support in intensive care unit for more than one month. He underwent treatment using a tilt table protocol with other routine treatment, which benefited him based on clinical as well as physiological variables. For practitioners in intensive care units, this report may offer perceptivity into the alternate practice of early mobilization using tilt table, and for investigators it may promote interest for further studies.

Hashim, Asiah M; Joseph, Leonard H; Embong, Juleida; Kasim, Zalila; Mohan, Vikram

2012-01-01

143

Advanced ventilator modes and techniques.  

PubMed

In addition to improving gas exchange by mechanical ventilation, minimizing iatrogenic lung injury and making the patient comfortable are important goals. This article reviews advanced ventilator modes and techniques that might help to accomplish these goals. Small tidal volumes (VT) and low ventilation pressure minimize ventilator-induced lung injury. Airway pressure release ventilation and high-frequency oscillatory ventilation may provide lung-protective ventilation in certain patients with refractory hypoxemia. Adaptive support ventilation (ASV) automatically adjusts VT and rate on the basis of the patient's respiratory mechanics to provide "safe" settings. When ventilator output does not match patient respiratory center timing, patient-ventilator asynchrony occurs. Proportional assist ventilation and neutrally adjusted ventilatory assist are unique modes of ventilation that provide ventilatory support in direct proportion to patient effort and therefore may be able to better match patient need and improve comfort. Weaning protocols reduce duration of ventilation and intensive care unit stay. Certain ventilator modes purport to automate part of the ventilator discontinuance process. The ASV progressively reduces support as the patient's lung condition improves, while SmartCare/pressure support (Dräger, Lübeck, Germany) reduces support and then initiates a spontaneous breathing trial. Further research is required to determine the proper place these new modes have in the intensive care unit. PMID:22157490

Haas, Carl F; Bauser, Kimberly A

2012-01-01

144

Expiratory flow limitation in morbidly obese postoperative mechanically ventilated patients.  

PubMed

Although obesity promotes tidal expiratory flow limitation (EFL), with concurrent dynamic hyperinflation (DH), intrinsic PEEP (PEEPi) and risk of low lung volume injury, the prevalence and magnitude of EFL, DH and PEEPi have not yet been studied in mechanically ventilated morbidly obese subjects. In 15 postoperative mechanically ventilated morbidly obese subjects, we assessed the prevalence of EFL [using the negative expiratory pressure (NEP) technique], PEEPi, DH, respiratory mechanics, arterial oxygenation and PEEPi inequality index as well as the levels of PEEP required to abolish EFL. In supine position at zero PEEP, 10 patients exhibited EFL with a significantly higher PEEPi and DH and a significantly lower PEEPi inequality index than found in the five non-EFL (NEFL) subjects. Impaired gas exchange was found in all cases without significant differences between the EFL and NEFL subjects. Application of 7.5 +/- 2.5 cm H2O of PEEP (range: 4-16) abolished EFL with a reduction of PEEPi and DH and an increase in FRC and the PEEPi inequality index but no significant effect on gas exchange. The present study indicates that: (a) on zero PEEP, EFL is present in most postoperative mechanically ventilated morbidly obese subjects; (b) EFL (and concurrent risk of low lung volume injury) is abolished with appropriate levels of PEEP; and (c) impaired gas exchange is common in these patients, probably mainly due to atelectasis. PMID:15352952

Koutsoukou, A; Koulouris, N; Bekos, B; Sotiropoulou, C; Kosmas, E; Papadima, K; Roussos, C

2004-10-01

145

Patient Machine Interface for the Control of Mechanical Ventilation Devices  

PubMed Central

The potential of Brain Computer Interfaces (BCIs) to translate brain activity into commands to control external devices during mechanical ventilation (MV) remains largely unexplored. This is surprising since the amount of patients that might benefit from such assistance is considerably larger than the number of patients requiring BCI for motor control. Given the transient nature of MV (i.e., used mainly over night or during acute clinical conditions), precluding the use of invasive methods, and inspired by current research on BCIs, we argue that scalp recorded EEG (electroencephalography) signals can provide a non-invasive direct communication pathway between the brain and the ventilator. In this paper we propose a Patient Ventilator Interface (PVI) to control a ventilator during variable conscious states (i.e., wake, sleep, etc.). After a brief introduction on the neural control of breathing and the clinical conditions requiring the use of MV we discuss the conventional techniques used during MV. The schema of the PVI is presented followed by a description of the neural signals that can be used for the on-line control. To illustrate the full approach, we present data from a healthy subject, where the inspiration and expiration periods during voluntary breathing were discriminated with a 92% accuracy (10-fold cross-validation) from the scalp EEG data. The paper ends with a discussion on the advantages and obstacles that can be forecasted in this novel application of the concept of BCI.

Grave de Peralta, Rolando; Gonzalez Andino, Sara; Perrig, Stephen

2013-01-01

146

A Prognostic Model for One-year Mortality in Patients Requiring Prolonged Mechanical Ventilation  

PubMed Central

Objective A measure that identifies patients who are at high risk of mortality after prolonged ventilation will help physicians communicate prognosis to patients or surrogate decision-makers. Our objective was to develop and validate a prognostic model for 1-year mortality in patients ventilated for 21 days or more. Design Prospective cohort study. Setting University-based tertiary care hospital Patients 300 consecutive medical, surgical, and trauma patients requiring mechanical ventilation for at least 21 days were prospectively enrolled. Measurements and Main Results Predictive variables were measured on day 21 of ventilation for the first 200 patients and entered into logistic regression models with 1-year and 3-month mortality as outcomes. Final models were validated using data from 100 subsequent patients. One-year mortality was 51% in the development set and 58% in the validation set. Independent predictors of mortality included requirement for vasopressors, hemodialysis, platelet count ?150 ×109/L, and age ?50. Areas under the ROC curve for the development model and validation model were 0.82 (se 0.03) and 0.82 (se 0.05) respectively. The model had sensitivity of 0.42 (se 0.12) and specificity of 0.99 (se 0.01) for identifying patients who had ?90% risk of death at 1 year. Observed mortality was highly consistent with both 3- and 12-month predicted mortality. These four predictive variables can be used in a simple prognostic score that clearly identifies low risk patients (no risk factors, 15% mortality) and high risk patients (3 or 4 risk factors, 97% mortality). Conclusions Simple clinical variables measured on day 21 of mechanical ventilation can identify patients at highest and lowest risk of death from prolonged ventilation.

Carson, Shannon S.; Garrett, Joanne; Hanson, Laura C.; Lanier, Joyce; Govert, Joe; Brake, Mary C.; Landucci, Dante L.; Cox, Christopher E.; Carey, Timothy S.

2009-01-01

147

Resting energy expenditure in Duchenne patients using home mechanical ventilation  

Microsoft Academic Search

Nutritional status is both important and difficult to assess in patients with Duchenne muscular dystrophy (DMD), particularly in those requiring mechanical ventilation (MV). The current authors evaluated body composition (bio-impedancemetry), resting energy expenditure (REE; indirect calorimetry) and energy intake in 20 adult patients with DMD using home MV (nocturnal: n513; continuous: n57) and 12 age-matched healthy controls. The patients were

J. Gonzalez-Bermejo; F. Lofaso; L. Falaize; M. Lejaille; T. Similowski

2005-01-01

148

[Weaning from mechanical ventilation. The aim of nursing research].  

PubMed

Management of patients difficult to wean from the ventilator is a practical challenge in which professional nurses are deeply involved.The clinical research applied over the last years has tried to describe the characteristics of weaning phenomenon and the associated factors, to find predictive outcomes to guide clinical decisions, to search new strategies to conduct the protocols and to identify the most effective modes of weaning. In this paper a critical review of the current knowledge from a nursing perspective is done. The weaning conceptual model proposed by the American Association of Critical Care Nurses (AACN) group has been used as a theoretical framework. PMID:11459536

Giménez, A M; Marín, B; Serrano, P; Fernández-Reyes, I; Ciudad, A; Asiain, M C; Montes, Y; Gómez, D; García, M R; Larrión, M M; Nicolás, M; Zazpe, C; Zubiri, M S

2001-01-01

149

Predictors of Time to Death After Terminal Withdrawal of Mechanical Ventilation in the ICU  

PubMed Central

Background: Little information exists about the expected time to death after terminal withdrawal of mechanical ventilation. We sought to determine the independent predictors of time to death after withdrawal of mechanical ventilation. Methods: We conducted a secondary analysis from a cluster randomized trial of an end-of-life care intervention. We studied 1,505 adult patients in 14 hospitals in Washington State who died within or shortly after discharge from an ICU following terminal withdrawal of mechanical ventilation (August 2003 to February 2008). Time to death and its predictors were abstracted from the patients’ charts and death certificates. Predictors included demographics, proxies of severity of illness, life-sustaining therapies, and International Classification of Diseases, 9th ed., Clinical Modification codes. Results: The median (interquartile range [IQR]) age of the cohort was 71 years (58-80 years), and 44% were women. The median (IQR) time to death after withdrawal of ventilation was 0.93 hours (0.25-5.5 hours). Using Cox regression, the independent predictors of a shorter time to death were nonwhite race (hazard ratio [HR], 1.17; 95% CI, 1.01-1.35), number of organ failures (per-organ HR, 1.11; 95% CI, 1.04-1.19), vasopressors (HR, 1.67; 95% CI, 1.49-1.88), IV fluids (HR, 1.16; 95% CI, 1.01-1.32), and surgical vs medical service (HR, 1.29; 95% CI, 1.06-1.56). Predictors of longer time to death were older age (per-decade HR, 0.95; 95% CI, 0.90-0.99) and female sex (HR, 0.86; 95% CI, 0.77-0.97). Conclusions: Time to death after withdrawal of mechanical ventilation varies widely, yet the majority of patients die within 24 hours. Subsequent validation of these predictors may help to inform family counseling at the end of life.

Hotchkin, David L.; Engelberg, Ruth A.; Rubinson, Lewis; Curtis, J. Randall

2010-01-01

150

Flexible bronchoscopy during mechanical ventilation in the prone position to treat acute lung injury.  

PubMed

In patients with severe acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) the prone position has been shown to improve survival of patients who are severely hypoxemic with an arterial oxygen tension to inspiratory oxygen fraction ratio (PaO(2)/FiO(2))<100. In those patients tracheobronchial toilette is crucial in preventing or treating airways obstructed by secretions and deterioration of oxygenation. Flexible fiberoptic bronchoscopy is widely recognized as an effective technique to perform bronchial toilette in the intensive care unit (ICU). Flexible bronchoscopy performed during prone mechanical ventilation in two cardiosurgical patients who developed ALI after complex surgery, proved feasible and safe and helped to avoid undesirable earlier cessation of prone mechanical ventilation. However decision making about bronchoscopy in severe hypoxia should be even more cautious than in the supine patient, as dangerous delay in resuscitation manoeuvres due to postponed switching the patient to the supine position should always be prevented. PMID:22868006

Guarracino, F; Bertini, P; Bortolotti, U; Stefani, M; Ambrosino, N

2013-01-01

151

[Design of a lung simulator for teaching lung mechanics in mechanical ventilation].  

PubMed

Over the last 10 years, noninvasive ventilation has become a treatment option for respiratory insufficiency in pulmonology services. The technique is currently included in pulmonology teaching programs. Physicians and nurses should understand the devices they use and the interaction between the patient and the ventilator in terms of respiratory mechanics, adaptation, and synchronization. We present a readily assembled lung simulator for teaching purposes that is reproducible and interactive. Based on a bag-in-box system, this model allows the concepts of respiratory mechanics in mechanical ventilation to be taught simply and graphically in that it reproduces the patterns of restriction, obstruction, and the presence of leaks. It is possible to demonstrate how each ventilation parameter acts and the mechanical response elicited. It can also readily simulate asynchrony and demonstrate how this problem can be corrected. PMID:18053545

Heili-Frades, Sarah; Peces-Barba, Germán; Rodríguez-Nieto, María Jesús

2007-12-01

152

Mechanical ventilation modulates TLR4 and IRAK3 in a non-infectious, ventilator-induced lung injury model  

Microsoft Academic Search

BACKGROUND: Previous experimental studies have shown that injurious mechanical ventilation has a direct effect on pulmonary and systemic immune responses. How these responses are propagated or attenuated is a matter of speculation. The goal of this study was to determine the contribution of mechanical ventilation in the regulation of Toll-like receptor (TLR) signaling and interleukin-1 receptor associated kinase-3 (IRAK-3) during

Jesús Villar; Nuria E Cabrera; Milena Casula; Carlos Flores; Francisco Valladares; Lucio Díaz-Flores; Mercedes Muros; Arthur S Slutsky; Robert M Kacmarek

2010-01-01

153

Differences in one-year health outcomes and resource utilization by definition of prolonged mechanical ventilation: a prospective cohort study  

PubMed Central

Introduction The outcomes of patients ventilated for longer than average are unclear, in part because of the lack of an accepted definition of prolonged mechanical ventilation (PMV). To better understand the implications of PMV provision, we compared one-year health outcomes between two common definitions of PMV as well as between PMV patients and those ventilated for shorter periods of time. Methods We conducted a secondary analysis of prospectively collected data from medical and surgical intensive care units at an academic tertiary care medical center. The study included 817 critically ill patients ventilated for ? 48 hours, 267 (33%) of whom received PMV based on receipt of a tracheostomy and ventilation for ? 96 hours. A total of 114 (14%) patients met the alternate definition of PMV by being ventilated for ? 21 days. Survival, functional status, and costs were measured at baseline and at 2, 6, and 12 months after discharge. Of one-year survivors, 71 (17%) were lost to follow up. Results PMV patients ventilated for ? 21 days had greater costs ($140,409 versus $143,389) and higher one-year mortality (58% versus 48%) than did PMV patients with tracheostomies who were ventilated for ? 96 hours. The majority of PMV deaths (58%) occurred after hospital discharge whereas 67% of PMV patients aged 65 years or older had died by one year. At one year PMV patients on average had limitations in two basic and five instrumental elements of functional status that exceeded both their pre-admission status and the one-year disability of those ventilated for < 96 hours. Costs per one-year survivor were $423,596, $266,105, and $165,075 for patients ventilated ? 21 days, ? 96 hours with a tracheostomy, and < 96 hours, respectively. Conclusion Contrasting definitions of PMV capture significantly different patient populations, with ? 21 days of ventilation specifying the most resource-intensive recipients of critical care. PMV patients, particularly the elderly, suffer from a significant burden of costly, chronic critical illness and are at high risk for death throughout the first year after intensive care.

Cox, Christopher E; Carson, Shannon S; Lindquist, Jennifer H; Olsen, Maren K; Govert, Joseph A; Chelluri, Lakshmipathi

2007-01-01

154

Should tracheostomy be performed as early as 72 hours in patients requiring prolonged mechanical ventilation?  

PubMed

Advances in treating the critically ill have resulted in more patients requiring prolonged airway intubation and respiratory support. If intubation is projected to be longer than several weeks, tracheostomy is often recommended. Tracheostomy offers the potential benefits of improved patient comfort, the ability to communicate, opportunity for oral feeding, and easier, safer nursing care. In addition, less need for sedation and lower airway resistance (than through an endotracheal tube) may facilitate the weaning process and shorten intensive care unit and hospital stay. By preventing microaspiration of secretions, tracheostomy might reduce ventilator-associated pneumonia. There is controversy, however, over the optimal timing of the procedure. While there have been many randomized controlled trials on tracheostomy timing, most were insufficiently powered to detect important differences, and systematic reviews and meta-analyses are limited by the heterogeneity of the primary studies. Based on the available data, we think it is reasonable to perform early tracheostomy in all patients projected to require prolonged mechanical ventilation. Unfortunately, identifying those patients can be difficult, and for many patient populations we lack the necessary tools to predict prolonged ventilation. We propose an early-tracheostomy decision algorithm. PMID:20040126

Durbin, Charles G; Perkins, Michael P; Moores, Lisa K

2010-01-01

155

A closed-loop controller for mechanical ventilation of patients with ARDS.  

PubMed

Mechanical ventilators are routinely used to care for patients who cannot adequately breath on their own. Management of mechanical ventilation often involves a careful watch of the patient's arterial blood-oxygen tension and requires frequent adjustment of ventilation parameters to optimize the therapy. This situation lends itself as a candidate for closed-loop control. This report describes a closed-loop control system based on well-established protocols to systematically maintain appropriate levels of positive end-expiratory pressure (PEEP) and inspired oxygen (FiO2) in patients with Adult Respiratory Distress Syndrome (ARDS). The closed-loop control system consists of an in-dwelling arterial oxygenation (PaO2) sensor (Pfizer Continucath), coupled to a Macintosh computer that continuously controls FiO2 and PEEP settings on a Hamilton Amadeus ventilator. The implemented protocols provide continuous closed-loop control of oxygenation and a balance between patient need and minimal therapy. The controller is based on a traditional proportional-integral-derivative (PID) approach. The idea is to control, or maintain, the patient's PaO2 level at a target value determined, or set, by the patient's physician. The controller also features non-linear and adaptive characteristics that allow the system to respond more aggressively to "threatening" levels of PaO2. Another benefit of the control system is the ability to display, monitor, record and store all system parameters, settings, and control variables for future analysis and study. The system was extensively tested in the laboratory and in animal trials prior to use on human subjects. The results of a small clinical trial indicated that the system maintained control of the patient's therapy nearly 84% of the time. During the remainder of this time, the controller was interrupted primarily for suctioning, PaO2 sensor calibration or replacement. The response of the closed-loop controller was found to be appropriate, reliable and safe in patients with ARDS. PMID:12085618

Anderson, Jeffrey R; East, Thomas D

2002-01-01

156

Ventilator-associated lung injury in patients without acute lung injury at the onset of mechanical ventilation  

Microsoft Academic Search

of mechanical ventilation. When expressed per predicted body weight, women were ventilated with larger tidal volume than men (mean 11.4 vs. 10.4 mL\\/kg predicted body weight, p < .001) and tended to develop acute lung injury more often (29% vs. 20%, p .068). In a multivariate analysis, the main risk factors associated with the development of acute lung injury were

Ognjen Gajic; Saqib I. Dara; Jose L. Mendez; Adebola O. Adesanya; Emir Festic; Sean M. Caples; Rimki Rana; Jennifer L. St. Sauver; James F. Lymp; Bekele Afessa; Rolf D. Hubmayr

2004-01-01

157

Ventilator-Associated Pneumonia in Neonatal and Pediatric Intensive Care Unit Patients  

PubMed Central

Ventilator-associated pneumonia (VAP) is the second most common hospital-acquired infection among pediatric intensive care unit (ICU) patients. Empiric therapy for VAP accounts for approximately 50% of antibiotic use in pediatric ICUs. VAP is associated with an excess of 3 days of mechanical ventilation among pediatric cardiothoracic surgery patients. The attributable mortality and excess length of ICU stay for patients with VAP have not been defined in matched case control studies. VAP is associated with an estimated $30,000 in attributable cost. Surveillance for VAP is complex and usually performed using clinical definitions established by the CDC. Invasive testing via bronchoalveolar lavage increases the sensitivity and specificity of the diagnosis. The pathogenesis in children is poorly understood, but several prospective cohort studies suggest that aspiration and immunodeficiency are risk factors. Educational interventions and efforts to improve adherence to hand hygiene for children have been associated with decreased VAP rates. Studies of antibiotic cycling in pediatric patients have not consistently shown this measure to prevent colonization with multidrug-resistant gram-negative rods. More consistent and precise approaches to the diagnosis of pediatric VAP are needed to better define the attributable morbidity and mortality, pathophysiology, and appropriate interventions to prevent this disease.

Foglia, Elizabeth; Meier, Mary Dawn; Elward, Alexis

2007-01-01

158

Inhibition of Janus kinase signaling during controlled mechanical ventilation prevents ventilation-induced diaphragm dysfunction  

PubMed Central

Controlled mechanical ventilation (CMV) is associated with the development of diaphragm atrophy and contractile dysfunction, and respiratory muscle weakness is thought to contribute significantly to delayed weaning of patients. Therefore, therapeutic strategies for preventing these processes may have clinical benefit. The aim of the current study was to investigate the role of the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in CMV-mediated diaphragm wasting and weakness in rats. CMV-induced diaphragm atrophy and contractile dysfunction coincided with marked increases in STAT3 phosphorylation on both tyrosine 705 (Tyr705) and serine 727 (Ser727). STAT3 activation was accompanied by its translocation into mitochondria within diaphragm muscle and mitochondrial dysfunction. Inhibition of JAK signaling during CMV prevented phosphorylation of both target sites on STAT3, eliminated the accumulation of phosphorylated STAT3 within the mitochondria, and reversed the pathologic alterations in mitochondrial function, reduced oxidative stress in the diaphragm, and maintained normal diaphragm contractility. In addition, JAK inhibition during CMV blunted the activation of key proteolytic pathways in the diaphragm, as well as diaphragm atrophy. These findings implicate JAK/STAT3 signaling in the development of diaphragm muscle atrophy and dysfunction during CMV and suggest that the delayed extubation times associated with CMV can be prevented by inhibition of Janus kinase signaling.—Smith, I. J., Godinez, G. L., Singh, B. K., McCaughey, K. M., Alcantara, R. R., Gururaja, T., Ho, M. S., Nguyen, H. N., Friera, A. M., White, K. A., McLaughlin, J. R., Hansen, D., Romero, J. M., Baltgalvis, K. A., Claypool, M. D., Li, W., Lang, W., Yam, G. C., Gelman, M. S., Ding, R., Yung, S. L., Creger, D. P., Chen, Y., Singh, R., Smuder, A. J., Wiggs, M. P., Kwon, O.-S., Sollanek, K. J., Powers, S. K., Masuda, E. S., Taylor, V. C., Payan, D. G., Kinoshita, T., Kinsella, T. M. Inhibition of Janus kinase signaling during controlled mechanical ventilation prevents ventilation-induced diaphragm dysfunction.

Smith, Ira J.; Godinez, Guillermo L.; Singh, Baljit K.; McCaughey, Kelly M.; Alcantara, Raniel R.; Gururaja, Tarikere; Ho, Melissa S.; Nguyen, Henry N.; Friera, Annabelle M.; White, Kathy A.; McLaughlin, John R.; Hansen, Derek; Romero, Jason M.; Baltgalvis, Kristen A.; Claypool, Mark D.; Li, Wei; Lang, Wayne; Yam, George C.; Gelman, Marina S.; Ding, Rongxian; Yung, Stephanie L.; Creger, Daniel P.; Chen, Yan; Singh, Rajinder; Smuder, Ashley J.; Wiggs, Michael P.; Kwon, Oh-Sung; Sollanek, Kurt J.; Powers, Scott K.; Masuda, Esteban S.; Taylor, Vanessa C.; Payan, Donald G.; Kinoshita, Taisei; Kinsella, Todd M.

2014-01-01

159

Bronchodilator delivery with metered-dose inhaler during mechanical ventilation  

PubMed Central

The delivery of bronchodilators with metered-dose inhaler (MDI) in mechanically ventilated patients has attracted considerable interest in recent years. This is because the use of the MDI has several advantages over the nebulizer, such as reduced cost, ease of administration, less personnel time, reliability of dosing and a lower risk of contamination. A spacer device is fundamental in order to demonstrate the efficacy of the bronchodilatory therapy delivered by MDI. Provided that the technique of administration is appropriate, MDIs are as effective as nebulizers, despite a significantly lower dose of bronchodilator given by the MDI.

Georgopoulos, Dimitris; Mouloudi, Eleni; Kondili, Eumorfia; Klimathianaki, Maria

2000-01-01

160

Prolonged mechanical ventilation associated with hypothyroidism after paediatric cardiac surgery.  

PubMed

Hypothyroidism in patients undergoing congenital heart defect surgery is known to be possible. This generally temporary condition can progress as it involves yet other factors, increasing the patients' time to heal. The case presented here is that of a 5-month-old girl who was dependent in the long term on mechanical ventilation following cardiac surgery. After having been diagnosed with hypothyroidism, she was extubated on the fourth day of her hormone replacement therapy, and discharged from hospital on the tenth day. PMID:23985069

Tanidir, Ibrahim C; Unuvar, Tolga; Haydin, Sertac

2014-08-01

161

Brief mechanical ventilation impacts airway cartilage properties in neonatal lambs  

PubMed Central

Ultrasound imaging allows in vivo assessment of tracheal kinetics and cartilage structure. To date, the impact of mechanical ventilation (MV) on extracellular matrix (ECM) in airway cartilage is unclear, but an indication of its functional and structural change may support the development of protective therapies. The objective of this study was to characterize changes in mechanical properties of the neonatal airway during MV with alterations in cartilage ECM. Trachea segments were isolated in a neonatal lamb model; ultrasound dimensions and pressure-volume relationships were measured on sham (no MV; n = 6) and MV (n = 7) airways for 4 h. Tracheal cross-sections were harvested at 4 h, tissues were fixed and stained, and Fourier transform infrared imaging spectroscopy (FT-IRIS) was performed. Over 4 h of MV, bulk modulus (28%) and elastic modulus (282%) increased. The MV tracheae showed higher collagen, proteoglycan content, and collagen integrity (new tissue formation); whereas no changes were seen in the controls. These data are clinically relevant in that airway properties can be correlated with MV and changes in cartilage extracellular matrix. Mechanical ventilation increases the in vivo dimensions of the trachea, and is associated with evidence of airway tissue remodeling. Injury to the neonatal airway from MV may have relevance for the development of tracheomalacia. We demonstrated active airway tissue remodeling during MV using a FT-IRIS technique which identifies changes in ECM.

Kim, Minwook; Pugarelli, Joan; Miller, Thomas L.; Wolfson, Marla R.; Dodge, George R.; Shaffer, Thomas H.

2012-01-01

162

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

NASA Astrophysics Data System (ADS)

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.

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

2010-04-01

163

Impact of tongue biofilm removal on mechanically ventilated patients  

PubMed Central

Objective To evaluate the effectiveness of a tongue cleaner in the removal of tongue biofilm in mechanically ventilated patients. Methods Tongue biofilm and tracheal secretion samples were collected from a total of 50 patients: 27 in the study group (SG) who were intubated or tracheostomized under assisted ventilation and treated with the tongue cleaner and 23 in the control group (CG) who did not undergo tongue cleaning. Oral and tracheal secretion cultures of the SG (initially and after 5 days) and the CG (at a single time-point) were performed to evaluate the changes in bacterial flora. Results The median age of the SG patients was 77 years (45-99 years), and that of the CG patients was 79 years (21-94 years). The length of hospital stay ranged from 17-1,370 days for the SG with a median stay of 425 days and from 4-240 days for the CG with a median stay of 120 days. No significant differences were found when the dental plaque indexes were compared between the SG and the CG. There was no correlation between the index and the length of hospital stay. The same bacterial flora was found in the dental plaque of 9 of the 27 SG patients before and after the tongue scraper was used for 5 days compared with the CG (p=0.683). Overall, 7 of the 27 SG patients had positive bacterial cultures for the same strains in both tongue biofilm and tracheal secretions compared with the CG (p=0.003). Significant similarities in strain resistance and susceptibility of the assessed microorganisms were observed between oral and tracheal microflora in 6/23 cases in the CG (p=0.006). Conclusion The use of a tongue cleaner is effective at reducing tongue biofilm in patients on mechanical ventilation and facilitates oral hygiene interventions performed by caregivers. Clinical Trials Registry NCT01294943

Santos, Paulo Sergio da Silva; Mariano, Marcelo; Kallas, Monira Samaan; Vilela, Maria Carolina Nunes

2013-01-01

164

Respirator triggering of electron-beam computed tomography (EBCT): differences in dynamic changes between augmented ventilation and controlled mechanical ventilation  

NASA Astrophysics Data System (ADS)

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.

Recheis, Wolfgang A.; Kleinsasser, Axel; Schuster, Antonius H.; Loeckinger, Alexander; Frede, Thomas; Springer, Peter; Hoermann, Christoph; zur Nedden, Dieter

2000-04-01

165

Mechanical ventilation during acute lung injury: current recommendations and new concepts.  

PubMed

Despite a very large body of investigations, no effective pharmacological therapies have been found to cure acute lung injury. Hence, supportive care with mechanical ventilation remains the cornerstone of treatment. However, several experimental and clinical studies showed that mechanical ventilation, especially at high tidal volumes and pressures, can cause or aggravate ALI. Therefore, current clinical recommendations are developed with the aim of avoiding ventilator-induced lung injury (VILI) by limiting tidal volume and distending ventilatory pressure according to the results of the ARDS Network trial, which has been to date the only intervention that has showed success in decreasing mortality in patients with ALI/ARDS. In the past decade, a very large body of investigations has determined significant achievements on the pathophysiological knowledge of VILI. Therefore, new perspectives, which will be reviewed in this article, have been defined in terms of the efficiency and efficacy of recognizing, monitoring and treating VILI, which will eventually lead to further significant improvement of outcome in patients with ARDS. PMID:22104487

Del Sorbo, Lorenzo; Goffi, Alberto; Ranieri, V Marco

2011-12-01

166

Mechanical ventilation, diaphragm weakness and weaning: a rehabilitation perspective.  

PubMed

Most patients are easily liberated from mechanical ventilation (MV) following resolution of respiratory failure and a successful trial of spontaneous breathing, but about 25% of patients experience difficult weaning. MV use leads to cellular changes and weakness, which has been linked to weaning difficulties and has been labeled ventilator induced diaphragm dysfunction (VIDD). Aggravating factors in human studies with prolonged weaning include malnutrition, chronic electrolyte abnormalities, hyperglycemia, excessive resistive and elastic loads, corticosteroids, muscle relaxant exposure, sepsis and compromised cardiac function. Numerous animal studies have investigated the effects of MV on diaphragm function. Virtually all these studies have concluded that MV use rapidly leads to VIDD and have identified cellular and molecular mechanisms of VIDD. Molecular and functional studies on the effects of MV on the human diaphragm have largely confirmed the animal results and identified potential treatment strategies. Only recently potential VIDD treatments have been tested in humans, including pharmacologic interventions and diaphragm "training". A limited number of human studies have found that specific diaphragm training can increase respiratory muscle strength in FTW patients and facilitate weaning, but larger, multicenter trials are needed. PMID:23692928

Daniel Martin, A; Smith, Barbara K; Gabrielli, Andrea

2013-11-01

167

Prevention of ventilator-associated pneumonia, mortality and all intensive care unit acquired infections by topically applied antimicrobial or antiseptic agents: a meta-analysis of randomized controlled trials in intensive care units  

Microsoft Academic Search

Introduction  Given the high morbidity and mortality attributable to ventilator-associated pneumonia (VAP) in intensive care unit (ICU)\\u000a patients, prevention plays a key role in the management of patients undergoing mechanical ventilation. One of the candidate\\u000a preventive interventions is the selective decontamination of the digestive or respiratory tract (SDRD) by topical antiseptic\\u000a or antimicrobial agents. We performed a meta-analysis to investigate the

Claudia Pileggi; Aida Bianco; Domenico Flotta; Carmelo GA Nobile; Maria Pavia

2011-01-01

168

A control system for mechanical ventilation of passive and active subjects.  

PubMed

Synchronization of spontaneous breathing with breaths supplied by the ventilator is essential for providing optimal ventilation to patients on mechanical ventilation. Some ventilation techniques such as Adaptive Support Ventilation (ASV), Proportional Assist Ventilation (PAV), and Neurally Adjusted Ventilatory Assist (NAVA) are designed to address this problem. In PAV, the pressure support is proportional to the patient's ongoing effort during inspiration. However, there is no guarantee that the patient receives adequate ventilation. The system described in this article is designed to automatically control the support level in PAV to guarantee delivery of patient's required ventilation. This system can also be used to control the PAV support level based on the patient's work of breathing. This technique further incorporates some of the features of ASV to deliver mandatory breaths for passive subjects. The system has been tested by using computer simulations and the controller has been implemented by using a prototype. PMID:23422078

Tehrani, Fleur T

2013-06-01

169

Development and validation of an algorithm for identifying prolonged mechanical ventilation in administrative data  

Microsoft Academic Search

Patients requiring prolonged mechanical ventilation (PMV) are a subset of critically ill patients with high resource utilization\\u000a and poor long-term outcomes. We sought to develop an algorithm for identifying patients receiving PMV, defined as either 14\\u000a or 21 days of mechanical ventilation, in administrative and claims data. The algorithm was derived in mechanically ventilated\\u000a patients at an academic medical center (n = 1,500)

Jeremy M. Kahn; Shannon S. Carson; Derek C. Angus; Walter T. Linde-Zwirble; Theodore J. Iwashyna

2009-01-01

170

[Pneumomediastinum: An aspect of pulmonary barotrauma during mechanical ventilation of acute respiratory distress syndrome].  

PubMed

Mechanical ventilation is a fundamental treatment of acute respiratory distress syndrome (ARDS). Despite compliance with the recommendations of protective mechanical ventilation, it can results in serious complications including the pulmonary barotrauma. This is often manifested by a pneumothorax. This observation describes an unusual aspect of barotrauma which is pneumomediastinum. The authors also point out the role of chest imaging in the management of mechanical ventilation during ARDS. PMID:24646783

Aissaoui, Y; En-Nafaa, I; Chkoura, K; Boughalem, M; Kamili, N Drissi

2014-06-01

171

Early tracheostomy in severe traumatic brain injury: evidence for decreased mechanical ventilation and increased hospital mortality  

PubMed Central

Objective: In the past, the authors performed a comprehensive literature review to identify all randomized controlled trials assessing the impact of early tracheostomy on severe brain injury outcomes. The search produced only two trials, one by Sugerman and another by Bouderka. Subjects and methods: The current authors initiated an Institutional Review Board-approved severe brain injury randomized trial to evaluate the impact of early tracheostomy on ventilator-associated pneumonia rates, intensive care unit (ICU)/ventilator days, and hospital mortality. Current study results were compared with the other randomized trials and a meta-analysis was performed. Results: Early tracheostomy pneumonia rates were Sugerman-48.6%, Bouderka-58.1%, and current study-46.7%. No early tracheostomy pneumonia rates were Sugerman-53.1%, Bouderka-61.3%, and current study-44.4%. Pneumonia rate meta-analysis showed no difference for early tracheostomy and no early tracheostomy (OR 0.89; p = 0.71). Early tracheostomy ICU/ventilator days were Sugerman-16 ± 5.9, Bouderka-14.5 ± 7.3, and current study-14.1 ± 5.7. No early tracheostomy ICU/ventilator days were Sugerman-19 ± 11.3, Bouderka-17.5 ± 10.6, and current study-17 ± 5.4. ICU/ventilator day meta-analysis showed 2.9 fewer days with early tracheostomy (p = 0.02). Early tracheostomy mortality rates were Sugerman-14.3%, Bouderka-38.7%, and current study-0%. No early tracheostomy mortality rates were Sugerman-3.2%, Bouderka-22.6%, and current study-0%. Randomized trial mortality rate meta-analysis showed a higher rate for early tracheostomy (OR 2.68; p = 0.05). Because the randomized trials were small, a literature assessment was undertaken to find all retrospective studies describing the association of early tracheostomy on severe brain injury hospital mortality. The review produced five retrospective studies, with a total of 3,356 patients. Retrospective study mortality rate meta-analysis demonstrated a larger mortality for early tracheostomy (OR 1.97; p < 0.0001). Conclusion: For severe brain injury, analyses indicate that ventilator-associated pneumonia rates are not decreased with early tracheostomy. Further, this study implies that mechanical ventilation is reduced with early tracheostomy. Both the randomized trial and retrospective meta-analysis indicate that risk for hospital death increases with early tracheostomy. Findings imply that early tracheostomy for severe brain injury is not a prudent routine policy.

Dunham, C Michael; Cutrona, Anthony F; Gruber, Brian S; Calderon, Javier E; Ransom, Kenneth J; Flowers, Laurie L

2014-01-01

172

Survival and quality of life outcome after mechanical ventilation in elderly stroke patients  

PubMed Central

Objectives: Mortality is high and functional outcome poor in mechanically ventilated stroke patients. In addition, age >65 years is an independent predictor of death at 2 months among these patients. Our objective was to determine survival rates, functional outcome, and quality of life (QoL) in stroke patients older than 65 years requiring mechanical ventilation. Methods: A prospective cohort study with an additional cross-sectional survey in 65 patients aged 65 years and older (mean age (SD): 75.6 (6.0) years) with ischaemic or haemorrhagic stroke who underwent mechanical ventilation. Main outcome measures were survival rate at 6 months, and Barthel Index (BI), modified Rankin Scale, and QoL at 15.8 (SD 8.0) months. Results: Survival rate at 6 months was 40%. Elective intubation (odds ratio (OR) 13.6; p = 0.002) was the only independent positive predictor for survival, while age >77.5 years (OR 0.1; p = 0.004) and white blood count >10/nl at admission (OR 0.31; p = 0.032) were independent negative predictors for survival at 6 months. At the time of the cross-sectional survey, BI was >70 in five out of 22 patients, 35–70 in three and <35 in the remaining 14 patients. QoL was impaired primarily in the physical domain, whereas the psychosocial domain was less affected. Conclusions: Although only 40% of elderly patients intubated in the acute phase of stroke survived at least 6 months, one in four survivors recovered to a good functional outcome with a reasonable QoL. Elderly stroke patients need to be selected carefully for intensive care treatment, but elective intubation to allow diagnostic procedures should not be withheld primarily based on their age.

Foerch, C; Kessler, K; Steckel, D; Steinmetz, H; Sitzer, M

2004-01-01

173

Injurious mechanical ventilation in the normal lung causes a progressive pathologic change in dynamic alveolar mechanics  

PubMed Central

Introduction Acute respiratory distress syndrome causes a heterogeneous lung injury, and without protective mechanical ventilation a secondary ventilator-induced lung injury can occur. To ventilate noncompliant lung regions, high inflation pressures are required to 'pop open' the injured alveoli. The temporal impact, however, of these elevated pressures on normal alveolar mechanics (that is, the dynamic change in alveolar size and shape during ventilation) is unknown. In the present study we found that ventilating the normal lung with high peak pressure (45 cmH20) and low positive end-expiratory pressure (PEEP of 3 cmH2O) did not initially result in altered alveolar mechanics, but alveolar instability developed over time. Methods Anesthetized rats underwent tracheostomy, were placed on pressure control ventilation, and underwent sternotomy. Rats were then assigned to one of three ventilation strategies: control group (n = 3, Pcontrol = 14 cmH2O, PEEP = 3 cmH2O), high pressure/low PEEP group (n = 6, Pcontrol = 45 cmH2O, PEEP = 3 cmH2O), and high pressure/high PEEP group (n = 5, Pcontrol = 45 cmH2O, PEEP = 10 cmH2O). In vivo microscopic footage of subpleural alveolar stability (that is, recruitment/derecruitment) was taken at baseline and than every 15 minutes for 90 minutes following ventilator adjustments. Alveolar recruitment/derecruitment was determined by measuring the area of individual alveoli at peak inspiration (I) and end expiration (E) by computer image analysis. Alveolar recruitment/derecruitment was quantified by the percentage change in alveolar area during tidal ventilation (%I – E?). Results Alveoli were stable in the control group for the entire experiment (low %I – E?). Alveoli in the high pressure/low PEEP group were initially stable (low %I – E?), but with time alveolar recruitment/derecruitment developed. The development of alveolar instability in the high pressure/low PEEP group was associated with histologic lung injury. Conclusion A large change in lung volume with each breath will, in time, lead to unstable alveoli and pulmonary damage. Reducing the change in lung volume by increasing the PEEP, even with high inflation pressure, prevents alveolar instability and reduces injury. We speculate that ventilation with large changes in lung volume over time results in surfactant deactivation, which leads to alveolar instability.

Pavone, Lucio A; Albert, Scott; Carney, David; Gatto, Louis A; Halter, Jeffrey M; Nieman, Gary F

2007-01-01

174

The role of tracheostomy in weaning from mechanical ventilation.  

PubMed

A common clinical observation is that patients wean more rapidly from mechanical ventilation following tracheotomy. Expected changes in tube resistance and dead space are not adequate to explain this observation in adult patients. Theoretical considerations are too complicated to allow evaluation of expected changes in work of breathing following tracheotomy. The resistance of the upper airway is about the same as breathing quietly through an 8.0 mm endotracheal tube; however, many patients experience a higher work of breathing following extubation. This is not true in infants, in whom the reduction in airway diameter is profound and a marked reduction in resistance is seen following extubation. The other benefits of tracheostomy include better secretion removal, improved oral hygiene, less laryngeal damage, and ability to eat and speak. These should be considered when proposing this procedure. There may be less late ventilator-associated pneumonia following early tracheotomy. The assumed better safety of tracheostomy has been questioned. That patients appear to wean more rapidly is probably accounted for by the variety of factors mentioned above. PMID:11929618

Jaeger, J Michael; Littlewood, Keith A; Durbin, Charles G

2002-04-01

175

Developing a readiness assessment tool for weaning patients under mechanical ventilation  

PubMed Central

Background: Mechanical ventilation is one of the major supportive interventions in intensive care units. Weaning the patients from mechanical ventilation and its related criteria are of great importance due to the related complications. As there is no comprehensive standard to allocate the time of weaning and due to lack of local research in this field, development of a comprehensive tool to measure patients’ readiness for weaning from mechanical ventilation is essential. Therefore, the present study was conducted with an aim to develop a readiness assessment tool for weaning patients from mechanical ventilation. Materials and Methods: This was a qualitative study with Delphi multi-triangulation design. In the first stage, the related items were extracted from the textbook and through searching the databases. In the second stage, after primary development of the items and based on supervisors’ indications, a questionnaire was made and used for assessment through Delphi methods. Twenty individuals, meeting the inclusion criteria, were selected through purposive sampling and their viewpoints concerning acceptability of the items were collected. In the third stage, the items with appropriateness over 70% were selected, and in the fourth stage, the final questionnaire was developed after a session with a panel of experts and supervisors. In the present study, in the first stage, the needed items were collected from various articles and books to provide items extraction. In stages two to four, manual calculation and investigation made by a panel of experts and the research team were adopted. Results: In the first stage, 100 articles and 51 related books were selected. In the second stage, 87 items were extracted from the articles and books and were sent as semi-open questions of assessment. In the third stage, 28 items with consensus >70% were extracted, and in the fourth stage, 26 items were selected by a panel of experts and the finalized questionnaire with the title “Persian Weaning Tool” (PWT) was developed in three domains: Respiration with 9 items, cardiovascular with 4 items, and other related factors with 13 items. Conclusions: A three-domain questionnaire is the product of experts’ consensus in the present study, which can be used to reduce the length of connection to mechanical ventilation and its complications.

Irajpour, Alireza; Khodaee, Mahnaz; Yazdannik, Ahmadreza; Abbasi, Saeed

2014-01-01

176

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

PubMed

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. PMID:22663966

Hess, Dean R

2012-06-01

177

Validity of the Modified Richmond Agitation-Sedation Scale for Use in Sedated, Mechanically Ventilated Swine  

PubMed Central

A valid and reliable scale for assessing level of sedation would facilitate appropriate sedation management in a porcine intensive care unit (ICU) model. The Richmond Agitation–Sedation Scale (RASS) is used often for human ICU patients. The purpose of this study was to estimate the content validity of the modified RASS for use in sedated, mechanically ventilated swine. The modified RASS includes descriptors specific for swine. A content validity assessment form was developed with 4 items and 5 response choices to assess the modified RASS for relevancy, sufficiency, clarity, and representativeness. The modified RASS and content validity assessment form were emailed to 23 veterinarians with experience in the care of swine or other large animals; participants judged the extent to which the modified RASS is valid for assessing sedation in mechanically ventilated critically ill swine. The criterion for acceptable validity evidence was a content validity index (CVI) of 0.80 or greater. Eight (67%) of 12 veterinarians who responded to the invitation to participate completed the assessment form. The item CVI varied from 0.50 to 0.88; scale CVI was 0.66. Because these values did not meet the a priori criterion, we concluded that the modified RASS does not have sufficient evidence of content validity for use with swine. The reliability of the modified RASS will be tested in the porcine ICU model, and experience with its use in swine will inform refinement of the scale descriptors for repeat assessment of content validity.

Leyden, Katrina N; Hanneman, Sandra K

2012-01-01

178

Increased duration of mechanical ventilation is associated with decreased diaphragmatic force: a prospective observational study  

Microsoft Academic Search

INTRODUCTION: Respiratory muscle weakness is an important risk factor for delayed weaning. Animal data show that mechanical ventilation itself can cause atrophy and weakness of the diaphragm, called ventilator-induced diaphragmatic dysfunction (VIDD). Transdiaphragmatic pressure after magnetic stimulation (TwPdi BAMPS) allows evaluation of diaphragm strength. We aimed to evaluate the repeatability of TwPdi BAMPS in critically ill, mechanically ventilated patients and

Greet Hermans; Anouk Agten; Dries Testelmans; Marc Decramer; Ghislaine Gayan-Ramirez

2010-01-01

179

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

PubMed

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

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

2014-07-01

180

Sleep Disturbances in Patients Admitted to a Step-Down Unit After ICU Discharge: the Role of Mechanical Ventilation  

PubMed Central

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.

Fanfulla, Francesco; Ceriana, Piero; D'Artavilla Lupo, Nadia; Trentin, Rossella; Frigerio, Francesco; Nava, Stefano

2011-01-01

181

A multicenter mortality prediction model for patients receiving prolonged mechanical ventilation  

PubMed Central

Objective Significant deficiencies exist in the communication of prognosis for patients requiring prolonged mechanical ventilation after acute illness, in part because of clinician uncertainty about long-term outcomes. We sought to refine a mortality prediction model for patients requiring prolonged ventilation using a multicentered study design. Design Cohort study. Setting Five geographically diverse tertiary care medical centers in the United States (California, Colorado, North Carolina, Pennsylvania, Washington). Patients Two hundred sixty adult patients who received at least 21 days of mechanical ventilation after acute illness. Interventions None. Measurements and Main Results For the probability model, we included age, platelet count, and requirement for vasopressors and/or hemodialysis, each measured on day 21 of mechanical ventilation, in a logistic regression model with 1-yr mortality as the outcome variable. We subsequently modified a simplified prognostic scoring rule (ProVent score) by categorizing the risk variables (age 18–49, 50–64, and >65 yrs; platelet count 0–150 and >150; vasopressors; hemodialysis) in another logistic regression model and assigning points to variables according to ? coefficient values. Overall mortality at 1 yr was 48%. The area under the curve of the receiver operator characteristic curve for the primary ProVent probability model was 0.79 (95% confidence interval, 0.75–0.81), and the p value for the Hosmer-Lemeshow goodness-of-fit statistic was .89. The area under the curve for the categorical model was 0.77, and the p value for the goodness-of-fit statistic was .34. The area under the curve for the ProVent score was 0.76, and the p value for the Hosmer-Lemeshow goodness-of-fit statistic was .60. For the 50 patients with a ProVent score >2, only one patient was able to be discharged directly home, and 1-yr mortality was 86%. Conclusion The ProVent probability model is a simple and reproducible model that can accurately identify patients requiring prolonged mechanical ventilation who are at high risk of 1-yr mortality.

Carson, Shannon S.; Kahn, Jeremy M.; Hough, Catherine L.; Seeley, Eric J.; White, Douglas B.; Douglas, Ivor S.; Cox, Christopher E.; Caldwell, Ellen; Bangdiwala, Shrikant I.; Garrett, Joanne M.; Rubenfeld, Gordon D.

2012-01-01

182

Stable Small Animal Mechanical Ventilation for Dynamic Lung Imaging to Support Computational Fluid Dynamics Models  

SciTech Connect

Pulmonary computational fluid dynamics models require 3D images to be acquired over multiple points in the dynamic breathing cycle, with no breath holds or changes in ventilatory mechanics. With small animals, these requirements result in long imaging times ({approx}90 minutes), over which lung mechanics, such as compliance, can gradually change if not carefully monitored and controlled. These changes, caused by derecruitment of parenchymal tissue, are manifested as an upward drift in peak inspiratory pressure or by changes in the pressure waveform and/or lung volume over the course of the experiment. We demonstrate highly repeatable mechanical ventilation in anesthetized rats over a long duration for pulmonary CT imaging throughout the dynamic breathing cycle. We describe significant updates to a basic commercial ventilator that was acquired for these experiments. Key to achieving consistent results was the implementation of periodic deep breaths, or sighs, of extended duration to maintain lung recruitment. In addition, continuous monitoring of breath-to-breath pressure and volume waveforms and long-term trends in peak inspiratory pressure and flow provide diagnostics of changes in breathing mechanics.

Jacob, Rick E.; Lamm, W. J.

2011-11-08

183

Construction of Prediction Module for Successful Ventilator Weaning  

Microsoft Academic Search

Ventilator weaning is the process of discontinuing mechanical ventilation from patients with respiratory failure. Previous\\u000a investigations reported that 39%-40% of the intensive care unit (ICU) patients need mechanical ventilator for sustaining their\\u000a lives. Among them, 90% of the patients can be weaned from the ventilator in several days while other 5%-15% of the patients\\u000a need longer ventilator support. Modern mechanical

Jiin-chyr Hsu; Yung-fu Chen; Hsuan-hung Lin; Chi-hsiang Li; Xiaoyi Jiang

2007-01-01

184

Effects of prolonged mechanical ventilation on respiratory muscle ultrastructure and mitochondrial respiration in rabbits  

Microsoft Academic Search

Objective. To investigate in rabbits whether prolonged mechanical ventilation (PMV) leads to ultrastructural changes in respiratory muscles and alters diaphragm mitochondrial respiration. Design and setting. Experimental prospective study in a university laboratory. Animals and interventions. We studied respiratory muscles of seven rabbits after 49ǃ h of controlled mechanical ventilation. Ten nonventilated rabbits were used as a control group. Measurements and

Nathalie Bernard; Stefan Matecki; Guillaume Py; Sandrine Lopez; Jacques Mercier; Xavier Capdevila

2003-01-01

185

Bronchodilator delivery by metered-dose inhaler in mechanically ventilated COPD patients: influence of flow pattern  

Microsoft Academic Search

Bronchodilator delivery by metered-dose inhaler in mechanically ventilated COPD patients: influence of flow pattern. E. Mouloudi, G. Prinianakis, E. Kondili, D. Georgopoulos. #ERS Journals Ltd 2000. ABSTRACT: In mechanically ventilated patients the flow pattern during bronch- odilator delivery by metered-dose inhaler (MDI) could be a factor that might influence the effectiveness of this therapy. In order to test this the

E. Mouloudi; G. Prinianakis; E. Kondili; D. Georgopoulos

2000-01-01

186

New perspectives on the evolution of lung ventilation mechanisms in vertebrates  

Microsoft Academic Search

In the traditional view of vertebrate lung ventilation mechanisms, air-breathing fishes and amphibians breathe with a buccal pump, and amniotes breathe with an aspiration pump. According to this view, no extant animal exhibits a mechanism that is intermediate between buccal pumping and aspiration breathing; all lung ventilation is produced either by expansion and compression of the mouth cavity via the

E. L. Brainerd

1999-01-01

187

Outcome of mechanical ventilation for acute respiratory failure in patients with pulmonary fibrosis  

Microsoft Academic Search

Objective: During the course of idiopathic pulmonary fibrosis patients may need invasive mechanical ventilation because of acute respiratory failure. We reviewed the charts of all patients with idiopathic pulmonary fibrosis admitted to our ICU for mechanical ventilation to describe their ICU course and prognosis. Design and setting: Retrospective, observational case series, from December 1996 to March 2001, in an 18-bed

Thierry Fumeaux; Claudia Rothmeier; Philippe Jolliet

2001-01-01

188

TLR2 Deficiency Aggravates Lung Injury Caused by Mechanical Ventilation.  

PubMed

Innate immunity pathways are found to play an important role in ventilator-induced lung injury. We analyzed pulmonary expression of Toll-like receptor 2 (TLR2) in humans and mice and determined the role of TLR2 in the pathogenesis of ventilator-induced lung injury in mice. Toll-like receptor 2 gene expression was analyzed in human bronchoalveolar lavage fluid (BALF) cells and murine lung tissue after 5 h of ventilation. In addition, wild-type (WT) and TLR2 knockout (KO) mice were ventilated with either lower tidal volumes (VT) of 7 mL/kg with positive end-expiratory pressure (PEEP) or higher VT of 15 mL/kg without PEEP for 5 h. Spontaneously breathing mice served as controls. Total protein and immunoglobulin M levels in BALF, neutrophil influx into the alveolar compartment, and interleukin 6 (IL-6), IL-1?, and keratinocyte-derived chemokine concentrations in lung tissue homogenates were measured. We observed enhanced TLR2 gene expression in BALF cells of ventilated patients and in lung tissue of ventilated mice. In WT mice, ventilation with higher VT without PEEP resulted in lung injury and inflammation with higher immunoglobulin M levels, neutrophil influx, and levels of inflammatory mediators compared with controls. In TLR2 KO mice, neutrophil influx and IL-6, IL-1?, and keratinocyte-derived chemokine were enhanced by this ventilation strategy. Ventilation with lower VT with PEEP only increased neutrophil influx and was similar in WT and TLR2 KO mice. In summary, injurious ventilation enhances TLR2 expression in lungs. Toll-like receptor 2 deficiency does not protect lungs from ventilator-induced lung injury. In contrast, ventilation with higher VT without PEEP aggravates inflammation in TLR2 KO mice. PMID:24667617

Kuipers, Maria Theresa; Jongsma, Geartsje; Hegeman, Maria A; Tuip-de Boer, Anita M; Wolthuis, Esther K; Choi, Goda; Bresser, Paul; van der Poll, Tom; Schultz, Marcus J; Wieland, Catharina W

2014-07-01

189

The impact of respiratory variables on mortality in non-ARDS and ARDS patients requiring mechanical ventilation  

Microsoft Academic Search

Objectives: Primarily, to determine if respiratory variables, assessed on a daily basis on days 1–6 after ICU admission, were associated\\u000a with mortality in non-ARDS and ARDS patients with respiratory failure requiring mechanical ventilation. Secondarily, to determine\\u000a non-respiratory factors associated with mortality in ARDS and non-ARDS patients. Design: Prospective multicentre clinical study. Setting: Seventy-eight intensive care units in Sweden and Iceland.

O. R. Luhr; M. Karlsson; A. Thorsteinsson; C. Rylander; C. G. Frostell

2000-01-01

190

Anaesthesia ventilators  

PubMed Central

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.

Jain, Rajnish K; Swaminathan, Srinivasan

2013-01-01

191

Anaesthesia ventilators.  

PubMed

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. PMID:24249886

Jain, Rajnish K; Swaminathan, Srinivasan

2013-09-01

192

Early and small changes in serum creatinine concentrations are associated with mortality in mechanically ventilated patients.  

PubMed

Emerging evidence suggests that minor changes in serum creatinine concentrations are associated with increased hospital mortality rates. However, whether serum creatinine concentration (SCr) on admission and its change are associated with an increased mortality rate in mechanically ventilated patients is not known. We have conducted an international, prospective, observational cohort study enrolling adult intensive care unit patients under mechanical ventilation (MV). Recursive partitioning was used to determine the values of SCr at the start of MV (SCr0) and the change in SCr ([DeltaSCr] defined as the maximal difference between the value at start of MV [day 0] and the value on MV day 2 at 8:00 am) that best discriminate mortality. In-hospital mortality, adjusted by a proportional hazards model, was the primary outcome variable. A total of 2,807 patients were included; median age was 59 years and median Simplified Acute Physiology Score II was 44. All-cause in-hospital mortality was 44%. The variable that best discriminated outcome was a SCr0 greater than 1.40 mg/dL (mortality, 57% vs. 36% for patients with SCr0 mechanically ventilated patients. PMID:20634655

Nin, Nicolás; Lombardi, Raúl; Frutos-Vivar, Fernando; Esteban, Andrés; Lorente, José A; Ferguson, Niall D; Hurtado, Javier; Apezteguia, Carlos; Brochard, Laurent; Schortgen, Fréderique; Raymondos, Konstantinos; Tomicic, Vinko; Soto, Luis; González, Marco; Nightingale, Peter; Abroug, Fekri; Pelosi, Paolo; Arabi, Yaseen; Moreno, Rui; Anzueto, Antonio

2010-08-01

193

Use of the oxygen cost of breathing as an index of weaning ability from mechanical ventilation  

Microsoft Academic Search

The oxygen cost of breathing (which is the difference in oxygen consumption measured during controlled ventilation and again\\u000a during spontaneous ventilation) was measured in 30 patients between the ages of 17 and 96 years at the time of commencement\\u000a of weaning from mechanical ventilation. There was a significant exponential correlation between the oxygen cost of breathing\\u000a in ml\\/m2\\/min and the

N. J. McDonald; P. Lavelle; W. N. Gallacher; R. P. Harpin

1988-01-01

194

Effects of ventilation in ventral decubitus position on respiratory mechanics in adult respiratory distress syndrome  

Microsoft Academic Search

Objective: To assess the potential benefits of a period of ventilation in ventral decubitus (VD) on oxygenation and respiratory mechanics\\u000a in the adult respiratory distress syndrome (ARDS).\\u000a \\u000a \\u000a Design: In a stable condition during baseline ventilation in dorsal decubitus (DD), after 15 min of ventilation in VD and after 10\\u000a min of restored DD, the following parameters were studied: arterial blood

G. Servillo; E. De Robertis; F. Rossano; R. Tufano; E. Roupie; L. Brochard; F. Lemaire

1997-01-01

195

Shortening the length of stay and mechanical ventilation time by using positive suggestions via MP3 players for ventilated patients  

PubMed Central

Long stay in intensive care unit (ICU) and prolonged ventilation are deleterious for subsequent quality of life and surcharge financial capacity. We have already demonstrated the beneficial effects of using suggestive communication on recovery time during intensive care. The aim of our present study was to prove the same effects with standardized positive suggestive message delivered by an MP3 player. Patients ventilated in ICU were randomized into a control group receiving standard ICU treatment and two groups with a standardized pre-recorded material delivered via headphones: a suggestive message about safety, self-control, and recovery for the study group and a relaxing music for the music group. Groups were similar in terms of age, gender, and mortality, but the SAPS II scores were higher in the study group than that in the controls (57.8 ± 23.6 vs. 30.1 ± 15.5 and 33.7 ± 17.4). Our post-hoc analysis results showed that the length of ICU stay (134.2 ± 73.3 vs. 314.2 ± 178.4 h) and the time spent on ventilator (85.2 ± 34.9 vs. 232.0 ± 165.6 h) were significantly shorter in the study group compared to the unified control. The advantage of the structured positive suggestive message was proven against both music and control groups.

Dioszeghy, Csaba; Frituz, Gabor; Gal, Janos; Varga, Katalin

2014-01-01

196

Implementing early mobilization interventions in mechanically ventilated patients in the ICU.  

PubMed

As ICU survival continues to improve, clinicians are faced with short- and long-term consequences of critical illness. Deconditioning and weakness have become common problems in survivors of critical illness requiring mechanical ventilation. Recent literature, mostly from a medical population of patients in the ICU, has challenged the patient care model of prolonged bed rest. Instead, the feasibility, safety, and benefits of early mobilization of mechanically ventilated ICU patients have been reported in recent publications. The benefits of early mobilization include reductions in length of stay in the ICU and hospital as well as improvements in strength and functional status. Such benefits can be accomplished with a remarkably acceptable patient safety profile. The importance of interactions between mind and body are highlighted by these studies, with improvements in patient awareness and reductions in ICU delirium being noted. Future research to address the benefits of early mobilization in other patient populations is needed. In addition, the potential for early mobilization to impact long-term outcomes in ICU survivors requires further study. PMID:22147819

Schweickert, William D; Kress, John P

2011-12-01

197

Recombinant Human Deoxyribonuclease Improves Atelectasis in Mechanically Ventilated Children with Cardiac Disease  

PubMed Central

Objective To investigate if a mucolytic agent, recombinant human deoxyribonuclease (rhDNase), improves atelectasis in children with cardiac illness requiring mechanical ventilation. Design A retrospective cohort study on consecutive patients receiving short-term (? 14 days) rhDNase therapy for atelectasis in the cardiac intensive care unit from January 2005 through February 2007 was carried out. Data relating to patient characteristics, gas exchange, ventilatory parameters and chest radiographs was collected and analyzed. The effectiveness of rhDNase therapy in the presence of neutrophils and/ or bacteria in the pre-rhDNase therapy tracheal aspirates was also investigated. Results rhDNase was effective in significantly improving established atelectasis without any major changes in gas exchange and ventilatory parameters. Therapeutic effect of rhDNase is most effective in ameliorating atelectasis in the lungs within 10 doses. rhDNase was more effective in improving chest radiographic atelectasis score in patients who had > moderate amounts PMN (p value= 0.0008), or bacteria (p value=0.007) or both (p value =0.004) present in their pre-rhDNase therapy trachea aspirate. No adverse effects were seen with rhDNase administration in the study cohort. Conclusions rhDNase can be safely and effectively used to improve atelectasis in mechanically ventilated children with cardiac disease especially in the presence of bacteria and/ or moderate amounts of PMN in the pre-rhDNase therapy tracheal aspirate.

Prodhan, P; Greenberg, B; Bhutta, AT; Hyde, C; Vankatesan, A; Imamura, M; Jaquiss, RDB; Dyamenahalli, U

2010-01-01

198

Numerical investigation of aerosolized drug delivery in the human lungs under mechanical ventilator conditions  

NASA Astrophysics Data System (ADS)

Particle deposition for aerosolized drug delivery in the human airways is heavily dependent upon flow conditions. Numerical modeling techniques have proven valuable for determining particle deposition characteristics under steady flow conditions. For the case of patients under mechanical ventilation, however, flow conditions change drastically and there is an increased importance to understand particle deposition characteristics. This study focuses on mechanically ventilated conditions in the upper trachea-bronchial (TB) region of the human airways. Solution of the continuous phase flow is done under ventilator waveform conditions with a suitable turbulence model in conjunction with a realistic model of upper TB airways. A discrete phase Euler-Lagrange approach is applied to solve for particle deposition characteristics with a focus on the effect of the ventilator inlet waveform. The purpose of this study is to accurately model flow conditions in the upper TB airways under mechanically ventilated conditions with a focus on real-time patient specific targeted aerosolized drug delivery.

Vanrhein, Timothy; Banerjee, Arindam

2010-11-01

199

Reduced mite allergen levels in dwellings with mechanical exhaust and supply ventilation.  

PubMed

Seventy similar bungalows constructed between 1968 and 1970 in the same suburban area of Stockholm were investigated regarding the content of house dust mite allergen, absolute indoor humidity, type of ventilation and basement construction. Houses with mechanical exhaust and supply ventilation had an indoor humidity above 7 g/kg less often than houses without this type of ventilation (Odds ratio 0.1, 95% confidence interval 0.0-0.2). Furthermore, only five of the 24 houses with exhaust and supply ventilation contained mattress dust mite allergen concentrations exceeding the median value (98.5 ng/g) compared with 30 of 46 hours which did not have such ventilation (odds ratio = 0.1, C.I. 0.0-0.5). Houses with both natural ventilation and crawl space basement harboured significantly less mattress mite allergen than houses having the same type of ventilation, but with a concrete slab basement. In a cold temperature climate, type of building construction and ventilation seem to be important for the occurrence of house dust mite allergens in dwellings. Our results indicate that modern energy-efficient houses should be equipped with mechanical exhaust and supply ventilation to reduce indoor air humidity during the dry winter months and the risk of mite infestation. PMID:8187025

Wickman, M; Emenius, G; Egmar, A C; Axelsson, G; Pershagen, G

1994-02-01

200

High levels of B-type natriuretic peptide predict weaning failure from mechanical ventilation in adult patients after cardiac surgery  

PubMed Central

OBJECTIVE: The failure to wean from mechanical ventilation is related to worse outcomes after cardiac surgery. The aim of this study was to evaluate whether the serum level of B-type natriuretic peptide is a predictor of weaning failure from mechanical ventilation after cardiac surgery. METHODS: We conducted a prospective, observational cohort study of 101 patients who underwent on-pump coronary artery bypass grafting. B-type natriuretic peptide was measured postoperatively after intensive care unit admission and at the end of a 60-min spontaneous breathing test. The demographic data, hemodynamic and respiratory parameters, fluid balance, need for vasopressor or inotropic support, and length of the intensive care unit and hospital stays were recorded. Weaning failure was considered as either the inability to sustain spontaneous breathing after 60 min or the need for reintubation within 48 h. RESULTS: Of the 101 patients studied, 12 patients failed the weaning trial. There were no differences between the groups in the baseline or intraoperative characteristics, including left ventricular function, EuroSCORE and lengths of the cardiac procedure and cardiopulmonary bypass. The B-type natriuretic peptide levels were significantly higher at intensive care unit admission and at the end of the breathing test in the patients with weaning failure compared with the patients who were successfully weaned. In a multivariate model, a high B-type natriuretic peptide level at the end of a spontaneous breathing trial was the only independent predictor of weaning failure from mechanical ventilation. CONCLUSIONS: A high B-type natriuretic peptide level is a predictive factor for the failure to wean from mechanical ventilation after cardiac surgery. These findings suggest that optimizing ventricular function should be a goal during the perioperative period.

Lara, Thiago Martins; Hajjar, Ludhmila Abrahao; de Almeida, Juliano Pinheiro; Fukushima, Julia Tizue; Barbas, Carmem Silvia Valente; Rodrigues, Adriano Rogerio Baldacin; Nozawa, Emilia; Feltrim, Maria Ignes Zanetti; Almeida, Elisangela; Coimbra, Vera; Osawa, Eduardo; de Moraes Ianotti, Rafael; Leme, Alcino Costa; Jatene, Fabio Biscegli; Auler-Jr., Jose Otavio Costa; Galas, Filomena Regina Barbosa Gomes

2013-01-01

201

Simulation on energy use for mechanical ventilation and air-conditioning (MVAC) systems in train compartments  

Microsoft Academic Search

Unlike the conventional automotive, modem railway trains are designed with non-openable windows; and a mechanical ventilation and air-conditioning (MVAC) system is installed in each train compartment for better indoor air quality as well as to provide a thermally comfortable environment. The ventilation rate is no doubt a critical element in the design of a MVAC system, especially in Hong Kong

W. K. Chow; Philip C. H. Yu

2000-01-01

202

Aerosol Delivery and Modern Mechanical Ventilation In Vitro\\/In Vivo Evaluation  

Microsoft Academic Search

Aerosol delivery via a mechanical ventilator remains unregulated with no standards for drug delivery to intubated patients. Bench models predicting drug delivery have not been validated in vivo. For modern ventilator designs, we chose to identify, on the bench, the most important variables affecting aerosol delivery and to correlate in vitro predictions of aerosol delivery with in vivo end points

Dorisanne D. Miller; Mohammad M. Amin; Lucy B. Palmer; Akbar R. Shah; Gerald C. Smaldone

203

Bronchodilator delivery with metered-dose inhalers in mechanically-ventilated patients  

Microsoft Academic Search

Metered-dose inhalers (MDIs) provide several advantages over nebu- lizers, including ease of administration, decreased cost, reliability of dosing, and freedom from contamination. However, this method of aerosol delivery has been considered ineffective in mechanically-ventilated patients because most of the aerosol deposits in the endotracheal tube and ventilator circuit. A smaller amount of aerosol from a MDI is deposited in the

R. Dhand; M. J. Tobin

1996-01-01

204

The pathogenesis of ventilator-associated pneumonia: I. Mechanisms of bacterial transcolonization and airway inoculation  

Microsoft Academic Search

Ventilator-associated pneumonia (VAP) is an infection of the lung parenchyma developing in patients on mechanical ventilation for more than 48 h. VAP is associated with a remarkably constant spectrum of pathogenic bacteria, most of which are aerobic Gramnegative bacilli (AGNB) and, to a lesser extentStaphyloccus aureus. Most authorities agree that VAP develops as a result of aspiration of secretions contaminated

R. J. Estes; G. U. Meduri

1995-01-01

205

SUMMERTIME CONCENTRATIONS AND EMISSIONS OF HYDROGEN SULFIDE AT A MECHANICALLY VENTILATED SWINE FINISHING BUILDING  

Microsoft Academic Search

Hydrogen sulfide (H2S) concentration and emission at a modern mechanically ventilated swine finishing building with a deep pit were continuously measured for three summer months. Ventilation rates, temperatures, and pig inventory in the building were also continuously measured or recorded. A total of 88 d of valid data were obtained between 26 June and 25 September, during which the average

J.-Q. Ni; A. J. Heber; C. A. Diehl; T. T. Lim; R. K. Duggirala; B. L. Haymore

206

A Novel Simple Internet-Based System for Real Time Monitoring and Optimizing Home Mechanical Ventilation  

Microsoft Academic Search

The dissemination of the available telemedicine systems for the optimization of home mechanical ventilation (HMV) is prevented by the need of complex infrastructures. We developed a device which, once connected to Internet through the mobile phone network, allows an authorized physician connected to Internet to monitor the ventilator signals and modify the settings in real-time without the need of external

Alessandro Gobbi; Leonardo Govoni; Daniel Navajas; Antonio Pedotti; Ramon Farré

2009-01-01

207

Assessment of total pulmonary airway resistance under mechanical ventilation.  

PubMed

We propose a procedure for assessing the pulmonary airway resistance of patients under mechanical ventilation with a volume-cycled respirator having a sine-wave flow curve and inspiration/expiration (I/E) ratio of 1/2. This simplified procedure requires only the respirator's manometer and spirometer. The method is based on Ohm's Law, dividing the pressure difference (as shown on the manometer) between the peak value and that obtained by occluding the expiratory outlet by one-tenth of the minute volume (Vm). The relationship between the Vm and flow is obtained by calculating the height of the triangle formed by the sine wave, given that the area approximates total volume and the base is derived from the frequency and I/E ratio. This method was tested in 296 measurements on 106 patients using as a control the determination of resistance with a pneumotachograph and differential manometer placed between the patient and respirator. There was a high correlation (r = 0.96) between both procedures. To further facilitate bedside use, we have prepared a graph relating common values of Vm and pressure to resistance. PMID:7428387

Gómez Rubí, J A; Sanmartin, A; Gonzalez Diaz, G; Apezteguia, C; Torres Martinez, G; Martin Rubí, J C

1980-11-01

208

Differences in the prognosis among severe trauma and medical patients requiring mechanical ventilation  

PubMed Central

Objetive. To find the differences between the prognosis of the patients with severe traumatism injury and those who were admitted with medical pathology who also required mechanical ventilation in our ICU. Patients and Method. Retrospective descriptive study in a polyvalent ICU of a third level hospital for a period of 8 years. Epidemiological variables such as age, sex, average stay, mortality, APACHE II at admission and days of mechanical ventilation, were analyzed in patients with severe traumatism injury and patients with medical pathology that were admitted in ICU and received mechanical ventilation during this period. Results. During the study period were admitted 208 patients with severe traumatism injury and 732 medical patients, all of them required mechanical ventilation. Patients with severe traumatism injury are more younger (41.8 vs 55.3 years, p = 0.001) and entered ICU in a state of minor severity, according to the prognostic index APACHE II (14.8 vs 17.4, p < 0.001), despite which they required more days of mechanical ventilation (9.8 vs 7.8 days, p = 0.017) and had a higher average stay (11.4 vs 9.4 days, p = 0.027), although the mortality was significantly lower (38.2% vs 28.2%, p = 0.005). Multivariate analysis showed as independent variables associated with mortality, the APACHE II (p < 0.0001), the average stay in ICU (p < 0.0001), days of mechanical ventilation (p < 0.0001) and type patient (p = 0.016). Conclusions. Patients with severe traumatic injury that require mechanical ventilation despite to be admitted in ICU in a state of greater severity, having an increased ICU stay and more days of mechanical ventilation, have a better prognosis than medical patients that required also mechanical ventilation at ICU stay, likely to be younger.

Santana-Cabrera, Luciano; Sanchez-Palacios, Manuel; Rodriguez, Alina Uriarte

2013-01-01

209

46 CFR 154.1205 - Mechanical ventilation system: Standards.  

Code of Federal Regulations, 2010 CFR

...may contain flammable cargo vapors. (i) Ventilation impellers and the housing in way of those impellers on a flammable cargo carrier must meet one of the following: (1) The impeller, housing, or both made of non-metallic material...

2010-10-01

210

46 CFR 154.1205 - Mechanical ventilation system: Standards.  

Code of Federal Regulations, 2010 CFR

...may contain flammable cargo vapors. (i) Ventilation impellers and the housing in way of those impellers on a flammable cargo carrier must meet one of the following: (1) The impeller, housing, or both made of non-metallic material...

2009-10-01

211

A randomized trial of chlorhexidine gluconate on oral bacterial pathogens in mechanically ventilated patients  

PubMed Central

Introduction Dental plaque biofilms are colonized by respiratory pathogens in mechanically-ventilated intensive care unit patients. Thus, improvements in oral hygiene in these patients may prevent ventilator-associated pneumonia. The goal of this study was to determine the minimum frequency (once or twice a day) for 0.12% chlorhexidine gluconate application necessary to reduce oral colonization by pathogens in 175 intubated patients in a trauma intensive care unit. Methods A randomized, double-blind, placebo-controlled clinical trial tested oral topical 0.12% chlorhexidine gluconate or placebo (vehicle alone), applied once or twice a day by staff nurses. Quantitation of colonization of the oral cavity by respiratory pathogens (teeth/denture/buccal mucosa) was measured. Results Subjects were recruited from 1 March, 2004 until 30 November, 2007. While 175 subjects were randomized, microbiologic baseline data was available for 146 subjects, with 115 subjects having full outcome assessment after at least 48 hours. Chlorhexidine reduced the number of Staphylococcus aureus, but not the total number of enterics, Pseudomonas or Acinetobacter in the dental plaque of test subjects. A non-significant reduction in pneumonia rate was noted in groups treated with chlorhexidine compared with the placebo group (OR = 0.54, 95% CI: 0.23 to 1.25, P = 0.15). No evidence for resistance to chlorhexidine was noted, and no adverse events were observed. No differences were noted in microbiologic or clinical outcomes between treatment arms. Conclusions While decontamination of the oral cavity with chlorhexidine did not reduce the total number of potential respiratory pathogens, it did reduce the number of S. aureus in dental plaque of trauma intensive care patients. Trial Registration clinicaltrials.gov NCT00123123.

2009-01-01

212

High-frequency ventilation and conventional mechanical ventilation in newborn babies with respiratory distress syndrome: A prospective, randomized trial  

Microsoft Academic Search

Objective. Morbidity and mortality remain high amongst babies ventilated for a respiratory distress syndrome (RDS). Whether newly developed ventilators allowing high frequency ventilation such as high frequen- cy flow interrupted ventilation (HFFIV) could decrease the morbidity and the mortality was investigated in a ran- domized study. Design: Preterm babies weighing < 1800 g suffering from RDS and ventilated by conventional

A. Pardou; D. Vermeylen; M. F. Muller; D. Detemmerman

1993-01-01

213

Stomach as a source of colonization of the respiratory tract during mechanical ventilation: association with ventilator-associated pneumonia  

Microsoft Academic Search

The aetiopathogenesis of ventilator-associated pneumonia (VAP) requires abnormal oropharyngeal and gastric colonization and the further aspira- tion of their contents to the lower airways. VAP develops easily if aspiration or inoculation of microorganisms occur in patients with artificial airways, in whom mechanical, cellular and\\/or humoral defences are altered. Well-known risk factors for gastric colonization include: alterations in gastric juice secretion;

A. Torres; M. El-Ebiary; N. Soler; C. Montón; N. Fàbregas; C. Hernández

1996-01-01

214

Nonpharmacological interventions to manage common symptoms in patients receiving mechanical ventilation.  

PubMed

Patients receiving mechanical ventilation can experience symptoms such as pain, anxiety, agitation, and lack of sleep while in the intensive care unit, all of which can affect healing. Nonpharmacological complementary therapies can be used as adjuncts to sedatives and analgesics. By incorporating appropriate use of complementary therapies in conjunction with mainstream medical therapies, nurses can decrease patients' anxiety, promote sleep, and promote a healing environment to improve outcomes. Minimizing noise and providing access to natural light help promote a healing environment. Methods to promote sleep include relaxation techniques such as progressive muscle relaxation and massage and communication with patients' and their families to determine the patients' normal sleep patterns. Complementary therapies to relieve anxiety and agitation include music intervention, imagery, presence, and animal-assisted therapy. PMID:21632591

Tracy, Mary Fran; Chlan, Linda

2011-06-01

215

Development and pilot testing of a decision aid for surrogates of patients with prolonged mechanical ventilation  

PubMed Central

Objective Shared decision making is inadequate in intensive care units (ICUs). Decision aids can improve decision making quality, though their role in an ICU setting is unclear. We aimed to develop and pilot test a decision aid for shared decision makers of patients undergoing prolonged mechanical ventilation. Setting ICUs at three medical centers. Subjects 53 surrogate decision makers and 58 physicians. Design and interventions We developed the decision aid using defined methodological guidelines. After an iterative revision process, formative cognitive testing was performed among surrogate-physician dyads. Next, we compared the decision aid to usual care control in a prospective, before/after design study. Measurements and main results Primary outcomes were physician-surrogate discordance for expected patient survival, comprehension of relevant medical information, and the quality of communication. Compared to control, the intervention group had lower surrogate-physician discordance (7 [10] vs 43 [21]), greater comprehension (11.4 [0.7] vs 6.1 [3.7]), and improved quality of communication (8.7 [1.3] vs 8.4 [1.3]) (all p<0.05) post-intervention. Hospital costs were lower in the intervention group ($110,609 vs $178,618; p=0.044); mortality did not differ by group (38% vs 50%, p=0.95). 94% of surrogates and 100% of physicians reported that the decision aid was useful in decision making. Conclusion We developed a prolonged mechanical ventilation decision aid that is feasible, acceptable, and associated with both improved decision making quality and less resource utilization. Further evaluation using a randomized controlled trial design is needed to evaluate the decision aid's effect on long-term patient and surrogate outcomes.

Cox, Christopher E.; Lewis, Carmen L.; Hanson, Laura C.; Hough, Catherine L.; Kahn, Jeremy M.; White, Douglas B.; Song, Mi-Kyung; Tulsky, James A.; Carson, Shannon S.

2013-01-01

216

The effect of expiratory rib cage compression before endotracheal suctioning on the vital signs in patients under mechanical ventilation  

PubMed Central

Background: In patients undergoing mechanical ventilation, mucus production and secretion is high as a result of the endotracheal tube. Because endotracheal suction in these patients is essential, chest physiotherapy techniques such as expiratory rib cage compression before endotracheal suctioning can be used as a means to facilitate mobilizing and removing airway secretion and improving alveolar ventilation. As one of the complications of mechanical ventilation and endotracheal suctioning is decrease of cardiac output, this study was carried out to determine the effect of expiratory rib cage compression before endotracheal suctioning on the vital signs in patients under mechanical ventilation. Materials and Methods: This study was a randomized clinical trial with a crossover design. The study subjects included 50 mechanically ventilated patients, hospitalized in intensive care wards of Valiasr and Mousavi hospitals in Zanjan, Iran. Subjects were selected by consecutive sampling and randomly allocated to groups 1 and 2. The patients received endotracheal suctioning with or without rib cage compression, with a minimum of 3 h interval between the two interventions. Expiratory rib cage compression was performed for 5 min before endotracheal suctioning. Vital signs were measured 5 min before and 15 and 25 min after endotracheal suctioning. Data were recorded on a data recording sheet. Data were analyzed using paired t-tests. Results: There were statistically significant differences in the means of vital signs measured 5 min before with 15 and 25 min after endotracheal suctioning with rib cage compression (P < 0. 01). There was no significant difference in the means of diastolic pressure measured 25 min after with baseline in this stage). But on the reverse mode, there was a significant difference between the means of pulse and respiratory rate 15 min after endotracheal suctioning and the baseline values (P < 0.002). This effect continued up to 25 min after endotracheal suctioning just for respiratory rate (P = 0.016). Moreover, there were statistically significant differences in the means of vital signs measured 5 min before and 15 min after endotracheal suctioning between the two methods (P ? 0001). Conclusions: Findings showed that expiratory rib cage compression before endotracheal suctioning improves the vital signs to normal range in patients under mechanical ventilation. More studies are suggested on performing expiratory rib cage compression before endotracheal suctioning in patients undergoing mechanical ventilation.

Bousarri, Mitra Payami; Shirvani, Yadolah; Agha-Hassan-Kashani, Saeed; Nasab, Nouredin Mousavi

2014-01-01

217

A microprocessor based feedback controller for mechanical ventilation.  

PubMed

A microcomputer feedback system has been developed which adjusts the inspired minute volume of a ventilator based on the patient's end-tidal CO2 concentration. The feedback controlled ventilator was evaluated in 6 dogs (18-20 kg). Arterial PCO2 was monitored continuously while end-tidal CO2 concentration was controlled by the micro-computer system and the following perturbations introduced: [1] NaHCO3 was infused IV, [2] a pulmonary artery was occluded, [3] one lumen of a double lumen endobronchial tube was occluded, and [4] an air embolism was given. The end-tidal PCO2 controller kept PaCO2 within 1.2 mm Hg of the desired value when CO2 production increased by as much as 44%. Changing the ventilation/perfusion ratios caused differences as large as 22 mm Hg between the arterial and end-tidal PCO2 and the controller was not effective in keeping PaCO2 at the desired level. Closed loop control of ventilation based on end-tidal PCO2 measurements successfully compensated for increases in CO2 production keeping PaCO2 constant. The controller did not, however, keep PaCO2 at the desired level when significant changes occurred in the distribution of blood flow to ventilation. PMID:6819792

Ohlson, K B; Westenskow, D R; Jordan, W S

1982-01-01

218

Evaluation of the Use of Capnography during the Transport of Critically Ill Mechanically Ventilated Patients.  

National Technical Information Service (NTIS)

Critically ill, mechanically ventilated, patients were monitored with manometry, spirometry, and capnography during intrahospital transport out of the ICU. Patients functioned as their own control, and medical personnel were 'blinded' to capnography for 5...

D. P. Stoltzfus

1992-01-01

219

Myocardial perfusion as assessed by thallium-201 scintigraphy during the discontinuation of mechanical ventilation in ventilator-dependent patients  

SciTech Connect

Patients who cannot be separated from mechanical ventilation (MV) after an episode of acute respiratory failure often have coexisting coronary artery disease. The authors hypothesized that increased left ventricular (LV) wall stress during periods of spontaneous ventilation (SV) could alter myocardial perfusion in these patients. Using thallium-201 (201TI) myocardial scintigraphy, the authors studied the occurrence of myocardial perfusion abnormalities during periods of SV in 15 MV-dependent patients (nine women, six men; aged 71 {plus minus} 7 yr, mean {plus minus} SD). Fourteen of these patients were studied once with 201TI myocardial scintigraphy during intermittent mechanical ventilation (IMV) and again on another day, after at least 10 min of SV through a T-piece. One patient was studied during SV only. Thirteen of 14 of the patients (93%) studied during MV had abnormal patterns of initial myocardial 201TI uptake, but only 1 patient demonstrated redistribution of 201TI on delayed images. The remainder of the abnormalities observed during MV were fixed defects. SV produced significant alterations of myocardial 201TI distribution or transient LV dilation, or both, in 7 of the 15 patients (47%). Four patients demonstrated new regional decreases of LV myocardial thallium concentration with redistribution of the isotope on delayed images. The patient studied only during SV also had myocardial 201TI defects with redistribution. Five patients (3 also having areas of 201TI redistribution) had transient LV dilation during SV.

Hurford, W.E.; Lynch, K.E.; Strauss, H.W.; Lowenstein, E.; Zapol, W.M. (Department of Anesthesia, Harvard Medical School, Massachusetts General Hospital, Boston (USA))

1991-06-01

220

Opioids for neonates receiving mechanical ventilation: a systematic review and meta-analysis  

Microsoft Academic Search

ObjectiveTo evaluate the effect of opioid analgesics, compared to placebo, no drug, or other non-opioid analgesics or sedatives, on pain, duration of mechanical ventilation, mortality, growth and neurodevelopmental outcomes in newborn infants on mechanical ventilation.MethodsThis was a systematic review and meta-analysis of randomised controlled trials (RCTs). Data sources used were Cochrane, MEDLINE, EMBASE and CINAHL databases, and references from review

R. Bellu; Koert de Waal; R. Zanini

2010-01-01

221

[Delayed diagnosis of a diaphragmatic hernia in a patient on mechanical ventilation].  

PubMed

Traumatic rupture of the diaphragm is uncommon. Its early diagnosis is a challenge in diagnostic imaging. We present the case of a male multiple trauma patient in whom a left diaphragmatic hernia was discovered on weaning from mechanical ventilation 23 days after admission. We discuss the key imaging features of diaphragmatic rupture based on its physiopathology and thoracoabdominal pressure gradients. Very few cases of radiologically documented diaphragmatic hernias masked by mechanical ventilation have been reported. PMID:20541784

Navallas, M; Borruel, S; Cano, R; Ibáñez, L

2010-01-01

222

Nosocomial and ventilator-associated pneumonia in a community hospital intensive care unit: a retrospective review and analysis  

PubMed Central

Background Nosocomial and ventilator-associated pneumonia (VAP) are causes of significant morbidity and mortality in hospitalized patients. We analyzed a) the incidence and the outcome of pneumonias caused by different pathogens in the intensive care unit (ICU) of a medium-sized twenty-four bed community hospital and b) the incidence of complications of such pneumonias requiring surgical intervention such as thoracotomy and decortication. Results We retrospectively reviewed the charts of patients diagnosed with nosocomial and ventilator-associated pneumonia in our ICU. Their bronchoalveolar lavage (BAL) and sputum cultures, antibiograms, and other clinical characteristics, including complications and need for tracheostomy, thoracotomy and decortication were studied. In a span of one year (2011–12), 43 patients were diagnosed with nosocomial pneumonia in our ICU. The median simplified acute physiology score (SAPS II) was 39. One or more gram negative organisms as the causative agents were present in 85% of microbiologic samples. The three most prevalent gram negatives were Stenotrophomonas maltophilia (34%), Pseudomonas aeurginosa (40%), and Acinetobacter baumannii (32%). Twenty eight percent of bronchoalveolar samples contained Staphylococcus aureus. Eight three percent of patients required mechanical ventilation postoperatively and 37% underwent tracheostony. Thirty five percent underwent thoracotomy and decortication because of further complications such as empyema and non-resolving parapneumonic effusions. A. baumannii, Klebsiella pneumonia extended spectrum beta lactam (ESBL) and P. aeurginosa had the highest prevalence of multi drug resistance (MDR). Fifteen patients required surgical intervention. Mortality from pneumonia was 37% and from surgery was 2%. Conclusion Nosocomial pneumonias, in particular the ones that were caused by gram negative drug resistant organisms and their ensuing complications which required thoracotomy and decortication, were the cause of significant morbidity in our intensive care unit. Preventative and more intensive and novel infection control interventions in reducing the incidence of nosocomial pneumonias are strongly emphasized.

2014-01-01

223

The impact of rescue or maintenance therapy with EGFR TKIs for Stage IIIb-IV non-squamous non-small-cell lung cancer patients requiring mechanical ventilation  

PubMed Central

Background The toxicity of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is less than that of cytotoxic agents. The reports of dramatic response and improvement in performance status with the use of EGFR TKIs may influence a physician’s decision-making for patients with non-squamous non-small cell lung cancer (NSCLC) and life-threatening respiratory distress. The aim of this study was to evaluate the outcome of rescue or maintenance therapy with EGFR TKI for stage IIIb-IV non-squamous NSCLC patients requiring mechanical ventilation. Methods Eighty-three Asian patients with stage IIIb-IV non-squamous NSCLC and who required mechanical ventilation between June 2005 and January 2010 were evaluated. Results Of the 83 patients, 16 (19%) were successfully weaned from the ventilator. The use of EGFR TKI as rescue or maintenance therapy during respiratory failure did not improve the rate of successful weaning (standard care 18% vs. with EGFR TKI, 22%; p?=?0.81) in univariate and multivariate analyses. Conclusions Rescue or maintenance therapy with EGFR TKI for stage IIIb-IV non-squamous NSCLC patients requiring mechanical ventilation was not associated with better outcome. An end-of-life discussion should be an important aspect in the care of this group of patients, since only 19% were successfully weaned from mechanical ventilation.

2014-01-01

224

Infiltration Effects on Residential Pollutant Concentrations for Continuous and Intermittent Mechanical Ventilation Approaches  

SciTech Connect

The prevailing residential ventilation standard in North America, American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 62.2, specifies volumetric airflow requirements as a function of the overall size of the home and the number of bedrooms, assumes a fixed, minimal amount of infiltration, and requires mechanical ventilation to achieve the remainder. The standard allows for infiltration credits and intermittent ventilation patterns that can be shown to provide comparable performance. Whole-house ventilation methods have a substantial effect on time-varying indoor pollutant concentrations. If alternatives specified by Standard 62.2, such as intermittent ventilation, are used, short-term pollutant concentrations could exceed acute health standards even if chronic health standards are met.The authors present a methodology for comparing ASHRAE- and non-ASHRAE-specified ventilation scenarios on relative indoor pollutant concentrations. We use numerical modeling to compare the maximum time-averaged concentrations for acute exposure relevant (1-hour, 8-hour, 24-hour ) and chronic exposure relevant (1-year) time periods for four different ventilation scenarios in six climates with a range of normalized leakage values. The results suggest that long-term concentrations are the most important metric for assessing the effectiveness of whole-house ventilation systems in meeting exposure standards and that, if chronic health exposure standards are met, acute standards will also be met.

Sherman, Max; Logue, Jennifer; Singer, Brett

2010-06-01

225

Measurement of respiratory mechanics using the Siemens Servo Ventilator 900C.  

PubMed

The interrupter technique involves measuring the pressure changes at the airway opening during sudden cessation of flow and has been advocated for monitoring respiratory mechanics in artificially ventilated patients. The Siemens Servo Ventilator 900C has the ability to make airway occlusions without interrupting the patient's respiratory support. This study was performed to determine the suitability of the end-inspiratory occlusion facility of the ventilator for interrupter measurements of respiratory resistance and compliance. Measurements were made in a physical model of the respiratory system consisting of two parallel compartments, whose individual resistances and elastances were independently determined. The accuracy of the resistance measurements made using the ventilator were found to be dependent on the inspiratory flow. With an inspiratory flow of 100 ml/s, the resistance of the system could be measured to within 18% of the true value, and the static compliance could be measured to within 26% of the true value. Much of the error in these determinations was due to the finite closure time of the valve in the ventilator, and to the compliance of the gas in the tubing connecting the ventilator with the model. We conclude that the Siemens Servo Ventilator 900C can be used to conveniently obtain estimates of resistance and compliance in ventilated patients. PMID:3480499

Sly, P D; Bates, J H; Milic-Emili, J

1987-01-01

226

Low skeletal muscle area is a risk factor for mortality in mechanically ventilated critically ill patients  

PubMed Central

Introduction Higher body mass index (BMI) is associated with lower mortality in mechanically ventilated critically ill patients. However, it is yet unclear which body component is responsible for this relationship. Methods This retrospective analysis in 240 mechanically ventilated critically ill patients included adult patients in whom a computed tomography (CT) scan of the abdomen was made on clinical indication between 1 day before and 4 days after admission to the intensive care unit. CT scans were analyzed at the L3 level for skeletal muscle area, expressed as square centimeters. Cutoff values were defined by receiver operating characteristic (ROC) curve analysis: 110 cm2 for females and 170 cm2 for males. Backward stepwise regression analysis was used to evaluate low-muscle area in relation to hospital mortality, with low-muscle area, sex, BMI, Acute Physiologic and Chronic Health Evaluation (APACHE) II score, and diagnosis category as independent variables. Results This study included 240 patients, 94 female and 146 male patients. Mean age was 57 years; mean BMI, 25.6 kg/m2. Muscle area for females was significantly lower than that for males (102?±?23 cm2 versus 158?±?33 cm2; P?mechanically ventilated critically ill patients, independent of sex and APACHE II score. Further analysis suggests muscle mass as primary predictor, not sex. BMI is not an independent predictor of mortality when muscle area is accounted for.

2014-01-01

227

[Conducting disaster assistance drills for patients who receive a home ventilator care].  

PubMed

Individual assistance plan in the event of disaster has been formulated for neurodegenerative disease patients who wear a ventilator. This study was conducted for evacuation drills by simulating an actual disaster. Disaster assistance drills were conducted with the participation of relevant parties like home care service providers and local community association; the drills were sought to make sure that patients could be transported safely. Problems and issues encountered in the drills were resolved by assistance plans for individuals who need assistance. Under the direction of visiting nurses, the drills were involved in removing the patient from the ventilator, transferring the patient from his or her bed to a reclining wheelchair, and transporting the patient to a nearby evacuation area. Two individuals were needed to move the wheelchair safely, one was needed to observe the patient's status and provide respiratory care, and the other one was to carry a portable aspirator, so a minimum of four individuals was needed. These drills revealed four things: (1) the patient should be registered with the local municipality as an individual who needs assistance in the event of a disaster, (2) patients should routinely interact with neighbors, (3) home care service providers should periodically assist patients in leaving the home, and (4) visiting nurses' stations should play a leading role in disaster assistance for patients on medical equipment. PMID:21368523

Hatanaka, Harumi; Miki, Sotomi; Yuasa, Naoki; Akiyama, Katsunori

2010-12-01

228

Prognostic indicators of mortality of mechanically ventilated patients with acute leukemia in a comprehensive cancer center  

PubMed Central

Background The prognosis for adult acute leukemia patients that require intensive care unit (ICU) admission and invasive mechanical ventilation is poor. We aimed to identify prognostic indicators of 30-day hospital mortality in adult patients who had acute leukemia and respiratory failure, who had received invasive mechanical ventilation in the ICU but who had not received blood and marrow transplantation, were not admitted due to cardiopulmonary arrest or myocardial infarction and, had not recently undergone surgery. Methods In this case-control study, we retrospectively reviewed the medical records of relevant patients >16 year old who had been admitted to the ICU at our institution over a 4-year period. The main outcome measure was 30-day hospital mortality. Univariate and multivariate analyses were conducted to determine significant predictors of death. Results For the 167 patients meeting our eligibility criteria, the median age was 61 years. The majority was admitted due to respiratory insufficiency/failure (69%). The 30-day hospital mortality rate was 62%. Independent predictors of 30-day hospital mortality were advanced disease status (odds ratio [OR]=3.34; 95% confidence interval [CI], 1.65-6.77) and increased organ failure at the time of intubation (OR=1.17; 95% CI, 1.03-1.33) per point increase in the SOFA score. Patients who had received endotracheal intubation within the first 24 h of ICU admission were less likely than others to die (OR=0.46, 95% CI, 0.23-0.91) within the next 30 days after admission to the hospital. Conclusion Advanced disease status and elevated SOFA scores at intubation are strong predictors of 30-day mortality in patients with acute leukemia and respiratory failure. The protective effect of early endotracheal intubation warrants further investigation.

PRICE, K. J.; CARDENAS-TURANZAS, M.; LIN, H.; RODEN, L.; NIGAM, R.; NATESE, J. L.

2014-01-01

229

Differences in one-year health outcomes and resource utilization by definition of prolonged mechanical ventilation: a prospective cohort study  

Microsoft Academic Search

INTRODUCTION: The outcomes of patients ventilated for longer than average are unclear, in part because of the lack of an accepted definition of prolonged mechanical ventilation (PMV). To better understand the implications of PMV provision, we compared one-year health outcomes between two common definitions of PMV as well as between PMV patients and those ventilated for shorter periods of time.

Christopher E Cox; Shannon S Carson; Jennifer H Lindquist; Maren K Olsen; Joseph A Govert; Lakshmipathi Chelluri

2007-01-01

230

Oral decontamination for prevention of pneumonia in mechanically ventilated adults: systematic review and meta-analysis  

Microsoft Academic Search

Objective To evaluate the effect of oral decontamination on the incidence of ventilator associated pneumonia and mortality in mechanically ventilated adults.Design Systematic review and meta-analysis.Data sources Medline, Embase, CINAHL, the Cochrane Library, trials registers, reference lists, conference proceedings, and investigators in the specialty.Review methods Two independent reviewers screened studies for inclusion, assessed trial quality, and extracted data. Eligible trials were

Ee Yuee Chan; Annie Ruest; Maureen O Meade; Deborah J Cook

2007-01-01

231

Bronchodilator delivery by metered-dose inhaler in mechanically ventilated COPD patients: influence of tidal volume  

Microsoft Academic Search

Objective: The delivery of bronchodilator drugs with metered-dose inhaler (MDI) and a spacer in mechanically ventilated patients has\\u000a become a widespread practice. However, the various ventilator settings that influence the efficacy of MDI are not well established.\\u000a The tidal volume (VT) during drug delivery has been suggested as one of the factors that might increase the effectiveness of this therapy.

E. Mouloudi; K. Katsanoulas; M. Anastasaki; S. Hoing; D. Georgopoulos

1999-01-01

232

Review of ventilatory techniques to optimize mechanical ventilation in acute exacerbation of chronic obstructive pulmonary disease  

PubMed Central

Chronic obstructive pulmonary disease (COPD) is a major global healthcare problem. Studies vary widely in the reported frequency of mechanical ventilation in acute exacerbations of COPD. Invasive intubation and mechanical ventilation may be associated with significant morbidity and mortality. A good understanding of the airway pathophysiology and lung mechanics in COPD is necessary to appropriately manage acute exacerbations and respiratory failure. The basic pathophysiology in COPD exacerbation is the critical expiratory airflow limitation with consequent dynamic hyperinflation. These changes lead to further derangement in ventilatory mechanics, muscle function and gas exchange which may result in respiratory failure. This review discusses the altered respiratory mechanics in COPD, ways to detect these changes in a ventilated patient and formulating ventilatory techniques to optimize management of respiratory failure due to exacerbation of COPD.

Reddy, Raghu M; Guntupalli, Kalpalatha K

2007-01-01

233

Trends in Outcomes and Hospitalization Charges among Mechanically Ventilated Patients with Myasthenia Gravis in the United States  

PubMed Central

Introduction: To assess the impact of new therapeutic strategies on outcome and cost of hospitalization among patients with myasthenia gravis (MG) who are mechanically ventilated in United States. Methods: Using a retrospective analysis of cross sectional survey, we determined the rates of occurrence, in-hospital outcomes, and mean hospital charges for patients hospitalized with MG requiring mechanical ventilation in 1991–1992 using the Nationwide Inpatient Survey (NIS) and compared these outcomes with homologous data from 2001–2002. NIS is the largest all-payer inpatient care database in the United States. Results: When comparing data from 2001–2002 with data from 1991–1992, we found a higher number of admissions for MG that required mechanical ventilation (994 vs. 652). The proportion of women was similar (53% vs. 60%). The average age (in years ± standard deviation) was significantly higher (65 ± 17 vs. 58 ± 18, p=0.0002). The length of hospitalization (in days ± standard deviation) was not different (22 ± 19 vs. 21 ± 16). Discharge to home occurred less frequently (29% vs. 60%, p=0.0001) and in hospital mortality minimally lower (13% vs. 15%). There was a significant increase in mean hospital charges ($118,000 vs. $84,100 adjusted for inflation, p=0.0001). In hospital mortality was higher among urban teaching hospitals compared with urban non teaching hospitals in 2001–2002. Conclusions: Despite improvement in therapeutic strategies from 1991 to 2002, there was only a modest reduction in mortality and no substantial reduction of length of hospitalization for patients with MG requiring mechanical ventilation.

Souayah, Nizar; Nasar, Abu; Suri, M. Fareed K.; Kirmani, Jawad F.; Ezzeddine, Mustapha A.; Qureshi, Adnan I.

2009-01-01

234

A comparison of surfactant delivery with conventional mechanical ventilation and partial liquid ventilation in meconium aspiration injury.  

PubMed

The objective of this study was to compare surfactant (SF) distribution and physiological effects after standard SF delivery during conventional mechanical ventilation (CMV) with that using partial liquid ventilation (PLV). A model of meconium aspiration syndrome (MAS) was developed using two groups of adult rats (n = 14). After meconium instillation of 2.5 ml kg(-1) (20% v/w), SF/CMV: (n = 7) CMV and SF/PLV: (n = 7) PLV, received 14C-labeled surfactant (4 ml kg(-1)) delivered intratracheally in four aliquots over 20 min in both groups. Sequential measurements of arterial blood chemistry and lung mechanics were performed in all animals. At the conclusion of experiments, lungs were inflated (30 cmH2O), dried, sectioned and evaluated for radioactivity in disintegrations per minute (DPM). Surfactant distribution was improved (P< 0.01) with PLV as compared to CMV with 48.8% of the pieces vs. 30.9% of the pieces receiving within 25% of the mean amount of surfactant, respectively. Further, regional distribution was also significantly more uniform with PLV than CMV: left vs right (P<0.01) lung and ventral vs. dorsal (P<0.01) regions. Finally, arterial PO2 and ventilation efficiency index were significantly (P<0.01) greater post-treatment in SF/PLV than SF/CMV. These data demonstrate surfactant delivery with PLV, as compared to CMV alone, to be an improved method of delivering surfactant in MAS and suggest the possible utility of SF/PLV combination therapy for its treatment of other etiologies of neonatal respiratory distress. PMID:11453320

Chappell, S E; Wolfson, M R; Shaffer, T H

2001-07-01

235

The use of 2% chlorhexidine gel and toothbrushing for oral hygiene of patients receiving mechanical ventilation: effects on ventilator-associated pneumonia  

PubMed Central

Objective To evaluate the effects of oral chlorhexidine hygiene with toothbrushing on the rate of ventilator-associated pneumonia in a mixed population of critically ill patients under prolonged mechanical ventilation. Methods Prospective, randomized, and placebo-controlled pilot study. Patients who were receiving mechanical ventilation, had been admitted less than 24 hours prior, and were anticipated to require mechanical ventilation for more than 72 hours were included in the study. The patients were randomly divided into one of the following groups: chlorhexidine hygiene with toothbrushing or a placebo group (gel with the same color and consistency and toothbrushing). Results The planned interim analysis was conducted using 52 patients, and the study was terminated prematurely. In total, 28 patients were included in the chlorhexidine / toothbrushing group, and 24 patients were included in the placebo group. Ventilator-associated pneumonia occurred in 45.8% of the placebo group and in 64.3% of the chlorhexidine hygiene with toothbrushing group (RR=1.4; 95% CI=0.83-2.34; p=0.29). Conclusion Because the study was terminated due to futility, it was not possible to evaluate the impact of oral hygiene using 2% chlorhexidine and toothbrushing on the incidence of ventilator-associated pneumonia in this heterogeneous population of critical patients receiving long-term mechanical ventilation, and no beneficial effect was observed for this intervention.

Meinberg, Maria Cristina de Avila; Cheade, Maria de Fatima Meinberg; Miranda, Amanda Lucia Dias; Fachini, Marcela Mascaro; Lobo, Suzana Margareth

2012-01-01

236

Assessment of Indoor Air Quality Benefits and Energy Costs of Mechanical Ventilation  

SciTech Connect

Intake of chemical air pollutants in residences represents an important and substantial health hazard. Sealing homes to reduce air infiltration can save space conditioning energy, but can also increase indoor pollutant concentrations. Mechanical ventilation ensures a minimum amount of outdoor airflow that helps reduce concentrations of indoor emitted pollutants while requiring some energy for fan(s) and thermal conditioning of the added airflow. This work demonstrates a physics based, data driven modeling framework for comparing the costs and benefits of whole-house mechanical ventilation and applied the framework to new California homes. The results indicate that, on a population basis, the health benefits from reduced exposure to indoor pollutants in New California homes are worth the energy costs of adding mechanical ventilation as specified by ASHRAE Standard 62.2.This study determines the health burden for a subset of pollutants in indoor air and the costs and benefits of ASHRAE's mechanical ventilation standard (62.2) for new California homes. Results indicate that, on a population basis, the health benefits of new home mechanical ventilation justify the energy costs.

Logue, J.M.; Price, P.N.; Sherman, M.H.; Singer, B.C.

2011-07-01

237

Role of brainstem centers in cardiorespiratory phase difference during mechanical ventilation.  

PubMed

During mechanical ventilation, large inter-patient and intra-patient variations of the phase of respiratory sinus arrhythmia (RSA) were described. To determine whether these variations were neurally mediated, we compared the RSA phase between: (1) 12 control subjects, (2) 23 mechanically ventilated patients without brain injury (MV group) and (3) 12 brain dead, mechanically ventilated patients, whose central nervous functions were abolished (BD group). ECG and ventilatory flow were recorded during 15 min and the RSA phase was then continuously computed by complex demodulation. Control group exhibited RSA phases between 180° and 250° whereas an opposite pattern, between 0° and 90°, was observed in the BD group. For the two groups, the phase was stable over time. In the MV group, the RSA phases were distributed between 0° and 260°, with a greater variability over time than the other groups. Therefore, during mechanical ventilation, brainstem centers may induce large variations of the RSA phase, not synchronous with the mechanical effect of ventilation. PMID:20434593

Van de Louw, Andry; Médigue, Claire; Papelier, Yves; Landrain, Morgan; Cottin, François

2010-11-30

238

Patient-ventilator asynchronies: may the respiratory mechanics play a role?  

PubMed Central

Introduction The mechanisms leading to patient/ventilator asynchrony has never been systematically assessed. We studied the possible association between asynchrony and respiratory mechanics in patients ready to be enrolled for a home non-invasive ventilatory program. Secondarily, we looked for possible differences in the amount of asynchronies between obstructive and restrictive patients and a possible role of asynchrony in influencing the tolerance of non-invasive ventilation (NIV). Methods The respiratory pattern and mechanics of 69 consecutive patients with chronic respiratory failure were recorded during spontaneous breathing. After that patients underwent non-invasive ventilation for 60 minutes with a "dedicated" NIV platform in a pressure support mode during the day. In the last 15 minutes of this period, asynchrony events were detected and classified as ineffective effort (IE), double triggering (DT) and auto-triggering (AT). Results The overall number of asynchronies was not influenced by any variable of respiratory mechanics or by the underlying pathologies (that is, obstructive vs restrictive patients). There was a high prevalence of asynchrony events (58% of patients). IEs were the most frequent asynchronous events (45% of patients) and were associated with a higher level of pressure support. A high incidence of asynchrony events and IE were associated with a poor tolerance of NIV. Conclusions Our study suggests that in non-invasively ventilated patients for a chronic respiratory failure, the incidence of patient-ventilator asynchronies was relatively high, but did not correlate with any parameters of respiratory mechanics or underlying disease.

2013-01-01

239

Pulmonary blood flow distribution in sheep: effects of anesthesia, mechanical ventilation, and change in posture  

NASA Technical Reports Server (NTRS)

BACKGROUND: Recent studies providing high-resolution images of pulmonary perfusion have questioned the classical zone model of pulmonary perfusion. Hence the present work was undertaken to provide detailed maps of regional pulmonary perfusion to examine the influence of anesthesia, mechanical ventilation, and posture. METHODS: Pulmonary perfusion was analyzed with intravenous fluorescent microspheres (15 microm) in six sheep studied in four conditions: prone and awake, prone with pentobarbital-anesthesia and breathing spontaneously, prone with anesthesia and mechanical ventilation, and supine with anesthesia and mechanical ventilation. Lungs were air dried at total lung capacity and sectioned into approximately 1,100 pieces (about 2 cm3) per animal. The pieces were weighed and assigned spatial coordinates. Fluorescence was read on a spectrophotometer, and signals were corrected for piece weight and normalized to mean flow. Pulmonary blood flow heterogeneity was assessed using the coefficient of variation of flow data. RESULTS: Pentobarbital anesthesia and mechanical ventilation did not influence perfusion heterogeneity, but heterogeneity increased when the animals were in the supine posture (P < 0.01). Gravitational flow gradients were absent in the prone position but present in the supine (P < 0.001 compared with zero). Pulmonary perfusion was distributed with a hilar-to-peripheral gradient in animals breathing spontaneously (P < 0.05). CONCLUSIONS: The influence of pentobarbital anesthesia and mechanical ventilation on pulmonary perfusion heterogeneity is small compared with the effect of changes in posture. Analysis of flow gradients indicate that gravity plays a small role in determining pulmonary blood flow distribution.

Walther, S. M.; Domino, K. B.; Glenny, R. W.; Hlastala, M. P.

1997-01-01

240

A Morphometric Model of Lung Mechanics for Time-Domain Analysis of Alveolar Pressures during Mechanical Ventilation  

Microsoft Academic Search

In this study we propose, and implement in the time domain, an anatomically consistent model of the respiratory system in critical care conditions that allows us to evaluate the impact of different ventilator strategies as well as of constrictive pathologies on the time course of acinar pressures and flows. We discuss the simplifications of the original Horsfield structure (Horsfield, K.,

Gianluca Nucci; Simonluca Tessarin; Claudio Cobelli

2002-01-01

241

Apnoea following normocapnic mechanical ventilation in awake mammals: a demonstration of control system inertia.  

PubMed Central

1. Inhibition of inspiratory muscle activity from volume-related feedback during mechanical ventilation has been shown previously. To determine if this neuromechanical inhibition displays a memory effect, the duration of expiration immediately following cessation of mechanical ventilation was assessed in eight normal subjects. The subjects were passively mechanically ventilated via a nasal mask until the end-tidal CO2 (PET,CO2) was a minimum of 30 mmHg and inspiratory effort was no longer detected, as evidenced by stabilization of mouth pressure and disappearance of surface diaphragm EMG activity. The ventilator output was held constant at a mean tidal volume (VT) of 1.0 l and breath duration of 4.6 s and PET,CO2 was increased 1-1.5 mmHg/min (via increased inspired CO2 fraction, FI,CO2) until inspiratory muscle activity returned. The PET,CO2 at which activation first occurred was defined as the CO2 recruitment threshold (PCO2,RT). The mechanical ventilation protocol was repeated and the PET,CO2 increased 1-1.5 mmHg/min until it was a mean of 1.1 mmHg above spontaneous PET,CO2 and 3.6 mmHg below PCO2,RT. After 4-6 min of mildly hypercapnic mechanical ventilation, the mechanical ventilation was terminated. 2. Following termination of mechanical ventilation, the duration of the subsequent apnoea was 14.6 +/- 2.8 s (mean +/- S.E.M.) or 453 +/- 123% > spontaneous TE and 178 +/- 62% > the TE chosen by the subject during 'assist control' ventilation at VT = 1.0 l. 3. To test the hypothesis that the apnoea following cessation of mechanical ventilation was due to a vagally mediated memory effect, the study was repeated in five double-lung transplant patients with similar PCO2,RT to normal subjects. These pulmonary vagally denervated patients also displayed an apnoea (14.5 +/- 4.0 s) upon cessation of mechanical ventilation (at a PET,CO2 2.0 mmHg > eupnoea and 2.4 mmHg < PCO2,RT), that was 367 +/- 162% > spontaneous TE. 4. We also found significant apnoea in the awake dog immediately following mildly hypercapnic passive mechanical ventilation, and this was similar before and after bilateral vagal blockade (15.7 +/- 1.3 and 19.7 +/- 4.7 s, respectively). 5. We conclude that neuromechanical inhibition of inspiratory muscle activity, produced by passive mechanical ventilation at high VT, exhibits a memory effect reflected in TE prolongation, which persists in the face of substantial increases in chemoreceptor stimuli. This effect is not dependent on vagal feedback from lung receptors. 6. We hypothesize that this persistent apnoea represents an inherent 'inertia', characteristic of the ventilatory control system.(ABSTRACT TRUNCATED AT 400 WORDS)

Leevers, A M; Simon, P M; Xi, L; Dempsey, J A

1993-01-01

242

Multicenter controlled trial comparing high-frequency jet ventilation and conventional mechanical ventilation in newborn infants with pulmonary interstitial emphysema.  

PubMed

One hundred forty-four newborn infants with pulmonary interstitial emphysema were stratified by weight and severity of illness, and randomly assigned to receive treatment with high-frequency jet ventilation (HFJV) or rapid-rate conventional mechanical ventilation (CV) with short inspiratory time. If criteria for treatment failure were met, crossover to the alternate ventilatory mode was permitted. Overall, 45 (61%) of 74 infants met treatment success criteria with HFJV compared with 26 (37%) of 70 treated with CV (p less than 0.01). Eighty-four percent of patients who crossed over from CV to HFJV initially responded to the new treatment, and 45% ultimately met success criteria on HFJV. In contrast, only 9% of those who crossed over from HFJV to CV responded well to CV (p less than 0.01), and the same 9% ultimately met success criteria (p less than 0.05). Therapy with HFJV resulted in improved ventilation at lower peak and mean airway pressures, as well as more rapid radiographic improvement of pulmonary interstitial emphysema, in comparison with rapid-rate CV. Survival by original assignment was identical. When survival resulting from rescue by the alternate therapy in crossover patients was excluded, the survival rate was 64.9% for HFJV, compared with 47.1% for CV (p less than 0.05). The incidence of chronic lung disease, intraventricular hemorrhage, patent ductus arteriosus, airway obstruction, and new air leak was similar in both groups. We conclude that HFJV, as used in this study, is safe and is more effective than rapid-rate CV in the treatment of newborn infants with pulmonary interstitial emphysema. PMID:1906102

Keszler, M; Donn, S M; Bucciarelli, R L; Alverson, D C; Hart, M; Lunyong, V; Modanlou, H D; Noguchi, A; Pearlman, S A; Puri, A

1991-07-01

243

Transmission of severe acute respiratory syndrome during intubation and mechanical ventilation.  

PubMed

Nosocomial transmission of severe acute respiratory syndrome from critically ill patients to healthcare workers has been a prominent and worrisome feature of existing outbreaks. We have observed a greater risk of developing severe acute respiratory syndrome for physicians and nurses performing endotracheal intubation (relative risk [RR], 13.29; 95% confidence interval [CI], 2.99 to 59.04; p = 0.003). Nurses caring for patients receiving noninvasive positive-pressure ventilation may be at an increased risk (RR, 2.33; 95% CI, 0.25 to 21.76; p = 0.5), whereas nurses caring for patients receiving high-frequency oscillatory ventilation do not appear at an increased risk (RR, 0.74; 95% CI, 0.11 to 4.92; p = 0.6) compared with their respective reference cohorts. Specific infection control recommendations concerning the care of critically ill patients may help limit further nosocomial transmission. PMID:14990393

Fowler, Robert A; Guest, Cameron B; Lapinsky, Stephen E; Sibbald, William J; Louie, Marie; Tang, Patrick; Simor, Andrew E; Stewart, Thomas E

2004-06-01

244

Mechanical ventilator design and function: the trigger variable.  

PubMed

Because of the design characteristics, flow-triggering appears to offer measurable advantages over pressure-triggering, particularly during spontaneous breathing. During the trigger phase, flow-triggering provides a relatively shorter time delay than pressure-triggering. A trigger sensitivity that does not cause autocycling can be set while a short time delay is maintained. It remains to be determined whether flow-triggering has less effect on the pressure-time product than pressure-triggering. During the post-trigger phase, the relatively optimal flow delivery with flow-by results in the maintenance of airway pressure at or above the end-expiratory airway pressure level. This accounts for the lower level of inspiratory muscle work observed with flow-by over that observed with demand-flow. Whether inspiratory muscle work on a demand-flow system with optimal flow delivery will be similar to that on flow-by is not known. With a flow-by or demand-flow system, the circuit pressure-sensing site influences the flow-pressure control algorithm in the post-trigger phase only. In microprocessor-based ventilators, the shortcomings seen with pressure-triggering during the post-trigger phase can unquestionably be overcome with a better ventilator algorithm design or the application of a small amount of pressure support. However, during the trigger phase, the impact of this effort is less clear. PMID:10145700

Sassoon, C S

1992-09-01

245

Impact of renal replacement therapy on the respiratory function of patients under mechanical ventilation  

PubMed Central

Objective To assess the oxygenation behavior and ventilatory mechanics after hemodialysis in patients under ventilatory support. Methods The present study was performed in the general intensive care unit of a tertiary public hospital. Patients over 18 years of age under mechanical ventilation and in need of dialysis support were included. Each patient was submitted to 2 evaluations (pre- and post-dialysis) regarding the cardiovascular and ventilatory parameters, the ventilatory mechanics and a laboratory evaluation. Results Eighty patients with acute or chronic renal failure were included. The analysis of the ventilatory mechanics revealed a reduction in the plateau pressure and an increased static compliance after dialysis that was independent of a reduction in blood volume. The patients with acute renal failure also exhibited a reduction in peak pressure (p=0.024) and an increase in the dynamic compliance (p=0.026), whereas the patients with chronic renal failure exhibited an increase in the resistive pressure (p=0.046) and in the resistance of the respiratory system (p=0.044). The group of patients with no loss of blood volume after dialysis exhibited an increase in the resistive pressure (p=0.010) and in the resistance of the respiratory system (p=0.020), whereas the group with a loss of blood volume >2,000mL exhibited a reduction in the peak pressure (p=0.027). No changes in the partial pressure of oxygen in arterial blood (PaO2) or in the PaO2/the fraction of inspired oxygen (PaO2/FiO2) ratio were observed. Conclusion Hemodialysis was able to alter the mechanics of the respiratory system and specifically reduced the plateau pressure and increased the static compliance independent of a reduction in blood volume.

Lopes, Fernanda Maia; Ferreira, Jose Roberval; Gusmao-Flores, Dimitri

2013-01-01

246

Chest compression with a higher level of pressure support ventilation: effects on secretion removal, hemodynamics, and respiratory mechanics in patients on mechanical ventilation*  

PubMed Central

OBJECTIVE: To determine the efficacy of chest compression accompanied by a 10-cmH2O increase in baseline inspiratory pressure on pressure support ventilation, in comparison with that of aspiration alone, in removing secretions, normalizing hemodynamics, and improving respiratory mechanics in patients on mechanical ventilation. METHODS: This was a randomized crossover clinical trial involving patients on mechanical ventilation for more than 48 h in the ICU of the Porto Alegre Hospital de Clínicas, in the city of Porto Alegre, Brazil. Patients were randomized to receive aspiration alone (control group) or compression accompanied by a 10-cmH2O increase in baseline inspiratory pressure on pressure support ventilation (intervention group). We measured hemodynamic parameters, respiratory mechanics parameters, and the amount of secretions collected. RESULTS: We included 34 patients. The mean age was 64.2 ± 14.6 years. In comparison with the control group, the intervention group showed a higher median amount of secretions collected (1.9 g vs. 2.3 g; p = 0.004), a greater increase in mean expiratory tidal volume (16 ± 69 mL vs. 56 ± 69 mL; p = 0.018), and a greater increase in mean dynamic compliance (0.1 ± 4.9 cmH2O vs. 2.8 ± 4.5 cmH2O; p = 0.005). CONCLUSIONS: In this sample, chest compression accompanied by an increase in pressure support significantly increased the amount of secretions removed, the expiratory tidal volume, and dynamic compliance. (ClinicalTrials.gov Identifier:NCT01155648 [http://www.clinicaltrials.gov/])

Naue, Wagner da Silva; Forgiarini, Luiz Alberto; Dias, Alexandre Simoes; Vieira, Silvia Regina Rios

2014-01-01

247

The preoperative and intraoperative risk factors for early postoperative mechanical ventilation after scoliosis surgery: A retrospective study  

PubMed Central

Background: Patients undergoing corrective surgery for scoliosis of spine are commonly ventilated in our institute after the operation. Postoperative mechanical ventilation (PMV) and subsequent prolongation of intensive care unit stay are associated with increase in medical expenditure and complications such as ventilator-associated pneumonia. Identification of factors which may contribute to PMV and their modification may help in allocation of resources effectively. The present study was performed to identify preoperative and intraoperative factors associated with early PMV after scoliosis surgery. Methods: One hundred and two consecutive patients who underwent operation for scoliosis correction between January 2006 to July 2011 were reviewed retrospectively. Patients requiring PMV included patients who were not extubated in the operating room and were continued on mechanical ventilation. Preoperative and intraoperative factors which were analysed included age, gender, weight, cardiorespiratory function, presence of kyphosis, number and level of vertebrae involved, surgical approach, whether thoracoplasty was done, duration of surgery, blood loss, fluids and blood transfused, hypothermia and use of antifibrinolytics. Results: The average age of the patients was 14.31±3.78 years with female preponderance (57.8%). Univariate analysis found that longer fusions of vertebrae (more than 8), blood loss, amount of crystalloids infused, blood transfused and hypothermia were significantly associated with PMV (P<0.05). Independent risk factors for PMV were longer fusion (Odds Ratio (OR), 1.290; 95% confidence interval (CI), 1.038-1.604) and hypothermia (OR, 0.096; 95% CI, 0.036-0.254; P<0.05). Conclusion: The authors identified that longer fusions and hypothermia were independent risk factors for early PMV. Implementation of measures to prevent hypothermia may result in decrease in PMV.

Gurajala, Indira; Ramachandran, Gopinath; Iyengar, Raju; Durga, Padmaja

2013-01-01

248

SIVA: a hybrid knowledge-and-model-based advisory system for intensive care ventilators.  

PubMed

The Sheffield Intelligent Ventilator Advisor is a hybrid knowledge-and-model-based advisory system designed for intensive care ventilator management. It consists of a top-level fuzzy rule-based module to give the qualitative component of the advice, and a lower-level model-based module to give the quantitative component of the advice. It is structured to offer adaptive patient-specific decision support. It can be operated in either invasive or noninvasive modes depending on the availability of data from invasive clinical measurements. The user can choose between the full-advisory mode and the clinician-directed mode. The advice given by the top-level module has been validated against retrospective real patient data and compared with intensivists expertise and performance under simulation conditions. Closed-loop simulations were performed assuming various clinical scenarios including sudden changes in the patient parameters such as the shunt or deadspace with noise and disturbances. They have shown that the advice given was appropriate and the blood gases resulting from the closed-loop decision support were acceptable. The system was also shown to be tolerant to noise and disturbances. It is implemented in MATLAB/SIMULINK and LabVIEW. PMID:15217261

Kwok, Hoi-Fei; Linkens, Derek A; Mahfouf, Mahdi; Mills, Gary H

2004-06-01

249

A Mobile Care System With Alert Mechanism  

Microsoft Academic Search

Abstract—Hypertension and arrhythmia are chronic diseases, which can be effectively prevented and controlled only if the physi- ological parameters of the patient are constantly monitored, along with the full support of the health education and professional med- ical care. In this paper, a role-based intelligent mobile care system with alert mechanism in chronic care environment is proposed and implemented. The

Ren-guey Lee; Kuei-chien Chen; Chun-chieh Hsiao; Chwan-lu Tseng

2007-01-01

250

Double impact of cigarette smoke and mechanical ventilation on the alveolar epithelial type II cell  

PubMed Central

Introduction Ventilator-induced lung injury (VILI) impacts clinical outcomes in acute respiratory distress syndrome (ARDS), which is characterized by neutrophil-mediated inflammation and loss of alveolar barrier function. Recent epidemiological studies suggest that smoking may be a risk factor for the development of ARDS. Because alveolar type II cells are central to maintaining the alveolar epithelial barrier during oxidative stress, mediated in part by neutrophilic inflammation and mechanical ventilation, we hypothesized that exposure to cigarette smoke and mechanical strain have interactive effects leading to the activation of and damage to alveolar type II cells. Methods To determine if cigarette smoke increases susceptibility to VILI in vivo, a clinically relevant rat model was established. Rats were exposed to three research cigarettes per day for two weeks. After this period, some rats were mechanically ventilated for 4 hours. Bronchoalveolar lavage (BAL) and differential cell count was done and alveolar type II cells were isolated. Proteomic analysis was performed on the isolated alveolar type II cells to discover alterations in cellular pathways at the protein level that might contribute to injury. Effects on levels of proteins in pathways associated with innate immunity, oxidative stress and apoptosis were evaluated in alveolar type II cell lysates by enzyme-linked immunosorbent assay. Statistical comparisons were performed by t-tests, and the results were corrected for multiple comparisons using the false discovery rate. Results Tobacco smoke exposure increased airspace neutrophil influx in response to mechanical ventilation. The combined exposure to cigarette smoke and mechanical ventilation significantly increased BAL neutrophil count and protein content. Neutrophils were significantly higher after smoke exposure and ventilation than after ventilation alone. DNA fragments were significantly elevated in alveolar type II cells. Smoke exposure did not significantly alter other protein-level markers of cell activation, including Toll-like receptor 4; caspases 3, 8 and 9; and heat shock protein 70. Conclusions Cigarette smoke exposure may impact ventilator-associated alveolar epithelial injury by augmenting neutrophil influx. We found that cigarette smoke had less effect on other pathways previously associated with VILI, including innate immunity, oxidative stress and apoptosis.

2014-01-01

251

Mechanical ventilation in the ICU- is there a gap between the time available and time used for nurse-led weaning?  

PubMed Central

Background Mechanical ventilation (MV) is a key component in the care of critically ill and injured patients. Weaning from MV constitutes a major challenge in intensive care units (ICUs). Any delay in weaning may increase the number of complications and leads to greater expense. Nurse-led, protocol-directed weaning has become popular, but it remains underused. The aim of this study was to identify and quantify discrepancies between the time available for weaning and time actually used for weaning. Further, we also wished to analyse patient and systemic factors associated with weaning activity. Methods This retrospective study was performed in a 12-bed general ICU at a university hospital. Weaning data were collected from 68 adult patients on MV and recorded in terms of ventilator-shifts. One ventilator-shift was defined as an 8-hour nursing shift for one MV patient. Results Of the 2000 ventilator-shifts analysed, 572 ventilator-shifts were available for weaning. We found that only 46% of the ventilator shifts available for weaning were actually used for weaning. While physician prescription of weaning was associated with increased weaning activity (p < 0.001), a large amount (22%) of weaning took place without physician prescription. Both increased nursing workload and night shifts were associated with reduced weaning activity. During the study period there was a significant increase in performed weaning, both when prescribed or not (p < 0.001). Conclusion Our study identified a significant gap between the time available and time actually used for weaning. While various patient and systemic factors were linked to weaning activity, the most important factor in our study was whether the intensive care nurses made use of the time available for weaning.

Hansen, Britt Saetre; Fjaelberg, Wenche Torunn Mathiesen; Nilsen, Odd Bjarte; Lossius, Hans Morten; S?reide, Eldar

2008-01-01

252

Immediate post-operative effects of tracheotomy on respiratory function during mechanical ventilation  

PubMed Central

Introduction Tracheotomy is widely performed in the intensive care unit after long-term oral intubation. The present study investigates the immediate influence of tracheotomy on respiratory mechanics and blood gases during mechanical ventilation. Methods Tracheotomy was performed in 32 orally intubated patients for 10.5 ± 4.66 days (all results are means ± standard deviations). Airway pressure, flow and arterial blood gases were recorded immediately before tracheotomy and half an hour afterwards. Respiratory system elastance (Ers), resistance (Rrs) and end-expiratory pressure (EEP) were evaluated by multiple linear regression. Respiratory system reactance (Xrs), impedance (Zrs) and phase angle (?rs) were calculated from Ers and Rrs. Comparisons of the mechanical parameters, blood gases and pH were performed with the aid of the Wilcoxon signed-rank test (P = 0.05). Results Ers increased (7 ± 11.3%, P = 0.001), whereas Rrs (-16 ± 18.4%, P = 0.0003), Xrs (-6 ± 11.6%, P = 0.006) and ? rs (-14.3 ± 16.8%, P = <0.001) decreased immediately after tracheotomy. EEP, Zrs, blood gases and pH did not change significantly. Conclusion Lower Rrs but also higher Ers were noted immediately after tracheotomy. The net effect is a non-significant change in the overall Rrs (impedance) and the effectiveness of respiratory function. The extra dose of anaesthetics (beyond that used for sedation at the beginning of the procedure) or a higher FiO2 (fraction of inspired oxygen) during tracheotomy or aspiration could be related to the immediate elastance increase.

Amygdalou, Argyro; Dimopoulos, George; Moukas, Markos; Katsanos, Christos; Katagi, Athina; Mandragos, Costas; Constantopoulos, Stavros H; Behrakis, Panagiotis K; Vassiliou, Miltos P

2004-01-01

253

Level of dyspnoea experienced in mechanically ventilated adults with and without saline instillation prior to endotracheal suctioning  

Microsoft Academic Search

The purpose of this study was to compare the level of dyspnoea with and without the use of 5-cc saline instillation prior to endotracheal suctioning of mechanically ventilated adults. A crossover, quasi-experimental design was used. Seventeen alert, mechanically ventilated adults were asked to rank their level of dyspnoea using the vertical visual analogue scale at specific time intervals surrounding two

Pamela V. O'Neal; Mary J. Grap; Carol Thompson; William Dudley

2001-01-01

254

Clinical review: Respiratory mechanics in spontaneous and assisted ventilation  

Microsoft Academic Search

Pulmonary disease changes the physiology of the lungs, which manifests as changes in respiratory mechanics. Therefore, measurement of respiratory mechanics allows a clinician to monitor closely the course of pulmonary disease. Here we review the principles of respiratory mechanics and their clinical applications. These principles include compliance, elastance, resistance, impedance, flow, and work of breathing. We discuss these principles in

Daniel C Grinnan; Jonathon Dean Truwit

2005-01-01

255

The implementation of an analgesia-based sedation protocol reduced deep sedation and proved to be safe and feasible in patients on mechanical ventilation  

PubMed Central

Introduction Deep sedation in critically ill patients is associated with a longer duration of mechanical ventilation and a prolonged length of stay in the intensive care unit. Several protocols have been used to improve these outcomes. We implement and evaluate an analgesia-based, goal-directed, nurse-driven sedation protocol used to treat critically ill patients who receive mechanical ventilation. Methods We performed a prospective, two-phase (before-after), non-randomized multicenter study that involved 13 intensive care units in Chile. After an observational phase (observational group, n=155), we designed, implemented and evaluated an analgesia-based, goal-directed, nurse-driven sedation protocol (intervention group, n=132) to treat patients who required mechanical ventilation for more than 48 hours. The primary outcome was to achieve ventilator-free days by day 28. Results The proportion of patients in deep sedation or in a coma decreased from 55.2% to 44.0% in the interventional group. Agitation did not change between the periods and remained approximately 7%. Ventilator-free days to day 28, length of stay in the intensive care unit and mortality were similar in both groups. At one year, post-traumatic stress disorder symptoms in survivors were similar in both groups. Conclusions We designed and implemented an analgesia-based, goal-directed, nurse-driven sedation protocol in Chile. Although there was no improvement in major outcomes, we observed that the present protocol was safe and feasible and that it resulted in decreased periods of deep sedation without increasing agitation.

Bugedo, Guillermo; Tobar, Eduardo; Aguirre, Marcia; Gonzalez, Hugo; Godoy, Jorge; Lira, Maria Teresa; Lora, Pilar; Encalada, Eduardo; Hernandez, Antonio; Tomicic, Vinko; Castro, Jose; Jara, Juan; Andresen, Max; Ugarte, Hector

2013-01-01

256

Assessment of Indoor Air Quality Benefits and Energy Costs of Mechanical Ventilation  

Microsoft Academic Search

Intake of chemical air pollutants in residences represents an important and substantial health hazard. Sealing homes to reduce air infiltration can save space conditioning energy, but can also increase indoor pollutant concentrations. Mechanical ventilation ensures a minimum amount of outdoor airflow that helps reduce concentrations of indoor emitted pollutants while requiring some energy for fan(s) and thermal conditioning of the

J. M. Logue; P. N. Price; M. H. Sherman; B. C. Singer

2011-01-01

257

Sinusitis in mechanically ventilated patients and its role in the pathogenesis of nosocomial pneumonia  

Microsoft Academic Search

Nosocomial sinusitis is a complication of endotracheal intubation and mechanical ventilation in critically ill patients. Its incidence is often underestimated because of a lack of clinical signs. It is suspected in patients with nasal discharge or unexplained fever. Its diagnosis is based on radiological examination, by radiograph or computed tomography scan, and microbiological cultures of maxillary sinus aspirate. Maxillary sinusitis

F. Bert; N. Lambert-Zechovsky

1996-01-01

258

Incidence and causes of non-invasive mechanical ventilation failure after initial success  

Microsoft Academic Search

BACKGROUNDThe rate of failure of non-invasive mechanical ventilation (NIMV) in patients with chronic obstructive pulmonary disease (COPD) with acute respiratory insufficiency ranges from 5% to 40%. Most of the studies report an incidence of “late failure” (after >48 hours of NIMV) of about 10–20%. The recognition of this subset of patients is critical because prolonged application of NIMV may unduly

Maurizio Moretti; Carmela Cilione; Auro Tampieri; Claudio Fracchia; Alessandro Marchioni; Stefano Nava

2000-01-01

259

Heliumoxygen reduces the production of carbon dioxide during weaning from mechanical ventilation  

Microsoft Academic Search

BACKGROUND: Prolonged weaning from mechanical ventilation has a major impact on ICU bed occupancy and patient outcome, and has significant cost implications. There is evidence in patients around the period of extubation that helium-oxygen leads to a reduction in the work of breathing. Therefore breathing helium-oxygen during weaning may be a useful adjunct to facilitate weaning. We hypothesised that breathing

Gordon Flynn; Gerlinde Mandersloot; Marie Healy; Mark Saville; Daniel F McAuley

2010-01-01

260

Nonchemical Elimination of Inspiratory Motor Output via Mechanical Ventilation in Sleep  

Microsoft Academic Search

In six dogs studied in nonrapid eye movement (NREM) sleep, we found that the frequency, volume, and timing of application of mechanical ventilator breaths had marked and sustained inhibi- tory effects on diaphragm electromyogram (EMG di ). Single venti- lator breaths of tidal volume (V T ) 75-200% of control caused ap- nea (up to three times eupneic expiratory time

MAKATO SATOH; PETER R. EASTWOOD; CURTIS A. SMITH; JEROME A. DEMPSEY

2001-01-01

261

USING OUTSIDE TEMPERATURE TO PREDICT ODOUR EMISSION FROM MECHANICAL VENTILATED LIVESTOCK BUILDINGS  

Microsoft Academic Search

Odour emission of livestock buildings is of interest for the residents in the vicinity of animal husbandry due to its annoying potential. To apply a Gauss dispersion model to odour emissions, the emission parameters have to be known. The emission parameters of a mechanically ventilated livestock building, the odour flow and the volume flow of the outlet air, are calculated

G. Schauberger; M. Piringer; E. Petz

2000-01-01

262

Mechanical ventilation of patients on long-term oxygen therapy with acute exacerbations of chronic obstructive pulmonary disease: prognosis and cost-utility analysis  

Microsoft Academic Search

Astract  \\u000a \\u000a Objective: To analyze the prognosis and costs of mechanical ventilation in patients with exacerbations of chronic obstructive pulmonary\\u000a disease (COPD) treated with long-term oxygen therapy. Design: A prospective cohort study. Follow-up at 1 and 5 years. Cost utility analysis. Setting: A medical-surgical intensive care unit (ICU) in a university hospital. Patients: 20 patients with previous COPD treated with long-term

J. M. Añón; A. García de Lorenzo; A. Zarazaga; V. Gómez-Tello; G. Garrido

1999-01-01

263

State of the evidence: mechanical ventilation with PEEP in patients with cardiogenic shock.  

PubMed

The need to provide invasive mechanical ventilatory support to patients with myocardial infarction and acute left heart failure is common. Despite the large number of patients requiring mechanical ventilation in this setting, there are remarkably few data addressing the ideal mode of respiratory support in such patients. Although there is near universal acceptance regarding the use of non-invasive positive pressure ventilation in patients with acute pulmonary oedema, there is more concern with invasive positive pressure ventilation owing to its more significant haemodynamic impact. Positive end-expiratory pressure (PEEP) is almost universally applied in mechanically ventilated patients due to benefits in gas exchange, recruitment of alveolar units, counterbalance of hydrostatic forces leading to pulmonary oedema and maintenance of airway patency. The limited available clinical data suggest that a moderate level of PEEP is safe to use in severe left ventricular (LV) dysfunction and cardiogenic shock, and may provide haemodynamic benefits as well in LV failure which exhibits afterload-sensitive physiology. PMID:23539555

Wiesen, Jonathan; Ornstein, Moshe; Tonelli, Adriano R; Menon, Venu; Ashton, Rendell W

2013-12-01

264

Children and Young People Requiring Home Assisted Ventilation in the South of England: Incidence, Receipt of Care Support and Components of the Care Package  

ERIC Educational Resources Information Center

The study found an increasing number of ventilator dependent children and young people living at home. Almost three quarters of the sample had a physical disability as a result of or in addition to their primary diagnosis. There was wide variation in the amount of paid care supporting these families which appeared unrelated to the level of…

While, Alison E.; Cockett, Andrea M.; Lewis, Samantha

2004-01-01

265

Experiences of exclusion when living on a ventilator: reflections based on the application of Julia Kristeva's philosophy to caring science.  

PubMed

The research presented in this work represents reflections in the light of Julia Kristeva's philosophy concerning empirical data drawn from research describing the everyday life of people dependent on ventilators. It also presents a qualitative and narrative methodological approach from a person-centred perspective. Most research on home ventilator treatment is biomedical. There are a few published studies describing the situation of people living at home on a ventilator but no previous publications have used the thoughts in Kristeva's philosophy applied to this topic from a caring science perspective. The paper also addresses what a life at home on a ventilator may be like and will hopefully add some new aspects to the discussion of philosophical issues in nursing and the very essence of care. Kristeva's philosophy embraces phenomena such as language, abjection, body, and love, allowing her writings to make a fruitful contribution to nursing philosophy in that they strengthen, expand, and deepen a caring perspective. Moreover, her writings about revolt having the power to create hope add an interesting aspect to the work of earlier philosophers and nursing theorists. PMID:21143574

Lindahl, Berit

2011-01-01

266

Respiratory variations in the arterial pressure during mechanical ventilation reflect volume status and fluid responsiveness.  

PubMed

Optimal fluid management is one of the main challenges in the care of the critically ill. However, the physiological parameters that are commonly monitored and used to guide fluid management are often inadequate and even misleading. From 1987 to 1989 we published four experimental studies which described a method for predicting the response of the cardiac output to fluid administration during mechanical ventilation. The method is based on the analysis of the variations in the arterial pressure in response to a mechanical breath, which serves as a repetitive hemodynamic challenge. Our studies showed that the systolic pressure variation and its components are able to reflect even small changes in the circulating blood volume. Moreover, these dynamic parameters provide information about the slope of the left ventricular function curve, and therefore predict the response to fluid administration better than static preload parameters.Many new dynamic parameters have been introduced since then, including the pulse pressure (PPV) and stroke volume (SVV) variations, and various echocardiographic and other parameters. Though seemingly different, all these parameters are based on measuring the response to a predefined preload-modifying maneuver. The clinical usefulness of these 'dynamic' parameters is limited by many confounding factors, the recognition of which is absolutely necessary for their proper use.With more than 20 years of hindsight we believe that our early studies helped pave the way for the recognition that fluid administration should ideally be preceded by the assessment of "fluid responsiveness". The introduction of dynamic parameters into clinical practice can therefore be viewed as a significant step towards a more rational approach to fluid management. PMID:24737260

Perel, Azriel; Pizov, Reuven; Cotev, Shamay

2014-06-01

267

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

PubMed Central

Background 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. Methods/Design 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. Discussion 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. Trial registration Clinicaltrials.gov NCT01683578 (registered on September 3 3012).

2014-01-01

268

Mechanical ventilation during experimental sepsis increases deposition of advanced glycation end products and myocardial inflammation  

Microsoft Academic Search

ABSTRACT: INTRODUCTION: Increasing evidence links advanced glycation end products (AGE) including N?-(carboxymethyl)lysine (CML) to the development of heart failure. Accumulation of AGE leads to myocardial inflammation, which is considered as one of the possible mechanisms underlying sepsis-induced cardiac dysfunction. We hypothesized that mechanical ventilation (MV) augmented sepsis-induced myocardial CML deposition and inflammation. METHODS: Sepsis was induced using a modified cecal

Martin CJ Kneyber; Roel P Gazendam; Hans WM Niessen; Jan-Willem Kuiper; Claudia C Dos Santos; Arthur S Slutsky; Frans B Plötz

2009-01-01

269

Mechanical ventilation after lung transplantation. An international survey of practices and preferences.  

PubMed

Rationale: Between 10% and 57% of lung transplant (LTx) recipients develop primary graft dysfunction (PGD) within 72 hours of LTx. PGD is clinically and histologically analogous to the acute respiratory distress syndrome. In patients at risk for or with acute respiratory distress syndrome, lung-protective ventilation strategies (low tidal volume and positive end-expiratory pressure) improve outcomes. There is, however, little information available on mechanical ventilation strategies after LTx. Objectives: Our aim in this international survey was to describe the current practices of mechanical ventilation immediately after LTx. Methods: An electronic survey was sent to the medical and surgical directors of U.S. LTx programs (n = 111) and to members of the Pulmonary Council of the International Society for Heart and Lung Transplantation (n = 470). Results: A total of 149 individuals from 18 countries responded to the questionnaire. The most common modes of ventilation were pressure assist/control (37%) and volume assist/control (35%). Tidal volumes were most often determined by recipient characteristics. Donor characteristics were rarely considered (35%) and were infrequently known by the team managing the ventilator (42%). When presented with a choice of ideal tidal volumes, a majority of respondents selected 6 ml/kg recipient predicted body weight (58%), fewer selected 10 ml/kg (21%), and none selected 15 ml/kg. A majority preferred limiting the fraction of inspired oxygen rather than positive end-expiratory pressure (PEEP) (69% versus 31%, P = 0.006). The median minimum PEEP was 5 cm H2O, and the median maximum PEEP was 11.5 cm H2O. The presence of PGD increased the perceived importance of monitoring plateau pressure to adjust tidal volumes. The median plateau pressure limit perceived as a threshold triggering reduction in tidal volume was 30 cm H2O. Conclusions: Most respondents reported using lung-protective approaches to mechanical ventilation after lung transplantation. Low tidal volumes based on recipient characteristics were frequently chosen. Donor characteristics often were not considered and frequently were not known by the team managing mechanical ventilation after LTx. PMID:24640938

Beer, Alison; Reed, Robert M; Bölükbas, Servet; Budev, Marie; Chaux, George; Zamora, Martin R; Snell, Gregory; Orens, Jonathan B; Klesney-Tait, Julia A; Schmidt, Gregory A; Brower, Roy G; Eberlein, Michael

2014-05-01

270

Reproducibility of quantitative cultures of endotracheal aspirates from mechanically ventilated patients.  

PubMed Central

Ventilator-associated pneumonia is frequently diagnosed with quantitative cultures of samples obtained by bronchoscopic techniques, a method associated with high costs and potential adverse effects. Quantitative cultures of endotracheal aspirates are easier and cheaper to obtain, and good correlations between the results of this method and those of bronchoscopic methods have been reported. However, the reproducibility of quantitative cultures of endotracheal aspirates has never been determined. We studied the quantitative analysis of endotracheal aspirates from 21 mechanically ventilated patients taken during two study days with 2- and 6-h intervals between samplings. In all, 40 endotracheal aspirates were obtained. For mechanically ventilated patients, the median variation of quantitative culture results was 12.3% (range, 0 to 63%), corresponding to 0.7 log CFU/ml. Furthermore, variation was independent of the interval of time between samplings. Persistence of significant numbers of pathogens in quantitative cultures (> or = 10(5) CFU/ml) of the consecutive endotracheal aspirates occurred in 82% of samples. We conclude that results of quantitative cultures from endotracheal aspirates are reproducible and may be useful in diagnosing ventilator-associated pneumonia.

Bergmans, D C; Bonten, M J; De Leeuw, P W; Stobberingh, E E

1997-01-01

271

Interactive effects of mechanical ventilation, inhaled nitric oxide and oxidative stress in acute lung injury.  

PubMed

To compare conventional mechanical ventilation (CMV) and high-frequency oscillatory ventilation (HFOV), with/without inhaled nitric oxide (iNO), for oxygenation, inflammation, antioxidant/oxidative stress status, and DNA damage in a model of acute lung injury (ALI). Lung injury was induced by tracheal infusion of warm saline. Rabbits were ventilated at [Formula: see text] 1.0 and randomly assigned to one of five groups. Overall antioxidant defense/oxidative stress was assessed by total antioxidant performance assay, and DNA damage by comet assay. Ventilatory and hemodynamic parameters were recorded every 30min for 4h. ALI groups showed worse oxygenation than controls after lung injury. After 4h of mechanical ventilation, HFOV groups presented significant improvements in oxygenation. HFOV with and without iNO, and CMV with iNO showed significantly increased antioxidant defense and reduced DNA damage than CMV without iNO. Inhaled nitric oxide did not beneficially affect HFOV in relation to antioxidant defense/oxidative stress and pulmonary DNA damage. Overall, lung injury was reduced using HFOV or CMV with iNO. PMID:24148688

Ronchi, Carlos Fernando; Ferreira, Ana Lucia Anjos; Campos, Fabio Joly; Kurokawa, Cilmery Suemi; Carpi, Mario Ferreira; Moraes, Marcos Aurélio; Bonatto, Rossano Cesar; Yeum, Kyung-Jin; Fioretto, Jose Roberto

2014-01-01

272

Electromagnetic interference by GSM cellular phones and UHF radios with intensive-care and operating-room ventilators.  

PubMed

The aim of this study was to evaluate the risks deriving from the interference by radio handsets (GSM cellular phones and UHF radios) with intensive-care and operating-room ventilators. Tests were conducted in three hospitals in Rome on 22 lung ventilators in accordance with the recommended practice ANSI C63.18-1997. When electromagnetic interference (EMI) effects occurred, the authors determined maximum interference distances. They also evaluated the distances at which the use of a given handset would result in a 5% and a 95% probability of interference. The degree of risk posed by each observed event was estimated, and safe distances are suggested. EMI events of varying degrees and natures were observed even with transmitters placed at a considerable distance. All observed effects were temporary. Only three ventilators of a certain model stopped working altogether and had to be reset. PMID:11098392

Barbaro, V; Bartolini, P; Benassi, M; Di Nallo, A M; Reali, L; Valsecchi, S

2000-01-01

273

Human versus Computer Controlled Selection of Ventilator Settings: An Evaluation of Adaptive Support Ventilation and Mid-Frequency Ventilation  

PubMed Central

Background. There are modes of mechanical ventilation that can select ventilator settings with computer controlled algorithms (targeting schemes). Two examples are adaptive support ventilation (ASV) and mid-frequency ventilation (MFV). We studied how different clinician-chosen ventilator settings are from these computer algorithms under different scenarios. Methods. A survey of critical care clinicians provided reference ventilator settings for a 70?kg paralyzed patient in five clinical/physiological scenarios. The survey-derived values for minute ventilation and minute alveolar ventilation were used as goals for ASV and MFV, respectively. A lung simulator programmed with each scenario's respiratory system characteristics was ventilated using the clinician, ASV, and MFV settings. Results. Tidal volumes ranged from 6.1 to 8.3?mL/kg for the clinician, 6.7 to 11.9?mL/kg for ASV, and 3.5 to 9.9?mL/kg for MFV. Inspiratory pressures were lower for ASV and MFV. Clinician-selected tidal volumes were similar to the ASV settings for all scenarios except for asthma, in which the tidal volumes were larger for ASV and MFV. MFV delivered the same alveolar minute ventilation with higher end expiratory and lower end inspiratory volumes. Conclusions. There are differences and similarities among initial ventilator settings selected by humans and computers for various clinical scenarios. The ventilation outcomes are the result of the lung physiological characteristics and their interaction with the targeting scheme.

Mireles-Cabodevila, Eduardo; Diaz-Guzman, Enrique; Arroliga, Alejandro C.; Chatburn, Robert L.

2012-01-01

274

A pilot study of nurse-led, home monitoring for patients with chronic respiratory failure and with mechanical ventilation assistance.  

PubMed

We assessed the feasibility of telemedicine for home monitoring of 45 patients with chronic respiratory failure (CRF) discharged from hospital. The patients transmitted pulsed arterial saturation (pSat) data via a telephone modem to a receiving station where a nurse was available for a teleconsultation. A respiratory physician was also available. Scheduled and ad hoc appointments were conducted. Thirty-five patients were on home mechanical ventilation, 13 with invasive and 22 with non-invasive devices. The main diagnosis was chronic obstructive pulmonary disease (COPD). The follow-up period was 176 days (SD 69). In all, 376 calls for scheduled consultations were received and 83 ad hoc consultations were requested by the patients. The actions taken were: 55 therapy modifications, 19 hospitalizations in a respiratory department for decompensated CRF, three hospitalizations in an intensive care unit (ICU), 22 requests for further investigations, 25 contacts with the general practitioner (GP), 66 demands for respiratory consultations and 10 calls for the emergency department. The mean time recorded for the 459 calls was 16 min/patient/week. In 82% of calls, a pSat recording was received successfully. The nurse time required to train the users in the operation of the pSat instrument was high (mean time 30 min). However, the results showed that home monitoring was feasible, and useful for titration of oxygen, mechanical ventilation setting and stabilization of relapses. PMID:17059649

Vitacca, M; Assoni, G; Pizzocaro, P; Guerra, A; Marchina, L; Scalvini, S; Glisenti, F; Spanevello, A; Bianchi, L; Barbano, L; Giordano, A; Balbi, B

2006-01-01

275

Mechanical ventilation drives pneumococcal pneumonia into lung injury and sepsis in mice: protection by adrenomedullin  

PubMed Central

Introduction Ventilator-induced lung injury (VILI) contributes to morbidity and mortality in acute respiratory distress syndrome (ARDS). Particularly pre-injured lungs are susceptible to VILI despite protective ventilation. In a previous study, the endogenous peptide adrenomedullin (AM) protected murine lungs from VILI. We hypothesized that mechanical ventilation (MV) contributes to lung injury and sepsis in pneumonia, and that AM may reduce lung injury and multiple organ failure in ventilated mice with pneumococcal pneumonia. Methods We analyzed in mice the impact of MV in established pneumonia on lung injury, inflammation, bacterial burden, hemodynamics and extrapulmonary organ injury, and assessed the therapeutic potential of AM by starting treatment at intubation. Results In pneumococcal pneumonia, MV increased lung permeability, and worsened lung mechanics and oxygenation failure. MV dramatically increased lung and blood cytokines but not lung leukocyte counts in pneumonia. MV induced systemic leukocytopenia and liver, gut and kidney injury in mice with pneumonia. Lung and blood bacterial burden was not affected by MV pneumonia and MV increased lung AM expression, whereas receptor activity modifying protein (RAMP) 1–3 expression was increased in pneumonia and reduced by MV. Infusion of AM protected against MV-induced lung injury (66% reduction of pulmonary permeability p?mechanically ventilated individuals with severe pneumonia.

2014-01-01

276

Development of Localized Pulmonary Interstitial Emphysema in a Late Preterm Infant without Mechanical Ventilation  

PubMed Central

Pulmonary interstitial emphysema (PIE) is not an uncommon finding in premature infants with respiratory distress who need respiratory support by mechanical ventilation. PIE has been reported in a few cases of neonates in whom either no treatment other than room air was given or they were given continuous positive end-expiratory pressure (CPAP) support. We present a case of a premature neonate who presented with respiratory distress, in whom PIE and spontaneous pneumothorax (PTX) developed while on CPAP therapy only. The patient was treated conservatively with subsequent resolution of the radiological findings and clinical improvement. No surgical intervention was required. It is important to know that PIE may develop independently of mechanical ventilation. We would like to add this case to the literature and describe the pertinent plain film and computed tomography (CT) findings of this entity, the possible mechanism of development, and the differential diagnosis. A review of the literature is also provided.

Soontarapornchai, Kultida; Perenyi, Agnes; Amodio, John

2014-01-01

277

Development of Localized Pulmonary Interstitial Emphysema in a Late Preterm Infant without Mechanical Ventilation.  

PubMed

Pulmonary interstitial emphysema (PIE) is not an uncommon finding in premature infants with respiratory distress who need respiratory support by mechanical ventilation. PIE has been reported in a few cases of neonates in whom either no treatment other than room air was given or they were given continuous positive end-expiratory pressure (CPAP) support. We present a case of a premature neonate who presented with respiratory distress, in whom PIE and spontaneous pneumothorax (PTX) developed while on CPAP therapy only. The patient was treated conservatively with subsequent resolution of the radiological findings and clinical improvement. No surgical intervention was required. It is important to know that PIE may develop independently of mechanical ventilation. We would like to add this case to the literature and describe the pertinent plain film and computed tomography (CT) findings of this entity, the possible mechanism of development, and the differential diagnosis. A review of the literature is also provided. PMID:24744939

Bawa, Pritish; Soontarapornchai, Kultida; Perenyi, Agnes; Goldfisher, Rachelle; Amodio, John

2014-01-01

278

Invasive mechanical ventilation in acute coronary syndromes in the era of percutaneous coronary intervention  

PubMed Central

Background: Percutaneous coronary intervention (PCI) improves prognosis in patients with acute coronary syndromes (ACS) reducing ischaemic complications and the development of heart failure, thus potentially changing invasive mechanical ventilation (IMV) requirements. Little information exists about patients with ACS requiring IMV in the current era. We aimed to analyze IMV requirements and characteristics of ACS patients treated under current recommendations (including a high rate of PCI). Methods: Baseline characteristics, indications for IMV, management and in-hospital and mid-term clinical course were analyzed prospectively in a consecutive series of patients with ACS admitted to a tertiary care hospital. Results: We included 1821 patients, of which 106 (5.8%) required IMV. Mean follow-up was 347 days. PCI was performed in 84% of cases. Patients with IMV had more comorbidities, worse left ventricular function and more unstable hemodynamic parameters on admission. In-hospital mortality in patients requiring IMV was 29%. These patients also had higher mid-term mortality (hazard ratio (HR) 6.58; 95% confidence interval (CI) 4.49?9.64; p 0.001). The most common indication for IMV was cardiopulmonary arrest (CA) (65; 61%), followed by pulmonary oedema (27; 26%) and shock (14; 13.2%). Patients with CA were younger, with better hemodynamic parameters at admission, more favourable coronary anatomy and higher rates of PCI. There were no significant differences in overall mortality between the three groups. The main cause of death in CA patients was persistent vegetative state. Conclusions: Mortality in patients with ACS requiring IMV remained high despite a high rate of PCI. Baseline characteristics, management and clinical course were different according to the reason for IMV. The most common cause for IMV requirement was CA.

Salazar-Mendiguchia, Joel; Lorente-Tordera, Victoria; Sanchez-Salado, Jose C; Gonzalez-Costello, Jose; Moliner-Borja, Pedro; Gomez-Hospital, Joan A; Manito-Lorite, Nicolas; Cequier-Fillat, Angel

2013-01-01

279

Heterogeneous Airway Versus Tissue Mechanics and Their Relation to Gas Exchange Function During Mechanical Ventilation  

Microsoft Academic Search

We have advanced a commercially available ventilator (NPB840, Puritan Bennett\\/Tyco Healthcare, Pleasanton, CA) to deliver an Enhanced Ventilation Waveform (EVW). This EVW delivers a broadband waveform that contains discrete frequencies blended to provide a tidal breath, followed by passive exhalation. The EVW allows breath-by-breath estimates of frequency dependence of lung and total respiratory resistance (R) and elastance (E) from 0.2

C. L. Bellardine; E. P. Ingenito; A. Hoffman; F. Lopez; W. Sanborn; B. Suki; K. R. Lutchen

2005-01-01

280

Influence of drive and timing mechanisms on breathing pattern and ventilation during mental task performance.  

PubMed

Assessment of multiple respiratory measures may provide insight into how behavioral demands affect the breathing pattern. This is illustrated by data from a study among 44 subjects, in which tidal volume, respiration rate, minute ventilation and indices of central drive and timing mechanisms were assessed via inductive plethysmography, in addition to end-tidal PCO2. After a baseline, three conditions of a memory comparison task were presented. The first two conditions differed only with regard to the presence or absence of feedback of performance (NFB and FB). In the third 'all-or-nothing' (AON) condition, subjects only received a monetary bonus, if their performance exceeded that of the previous two conditions. Minute ventilation increased from baseline to all task conditions, and from NFB and FB to AON. Respiration rate increased in all task conditions, but there were no differences between task conditions. Tidal volume decreased during NFB, but was equal to baseline during FB and AON. Of the respiratory control indices, inspiratory flow rate covaried much more closely with minute ventilation than duty cycle. The task performance induced a minor degree of hyperventilation. The discussion focusses on how behavioral demands affect respiratory control processes to produce alterations in breathing pattern and ventilation. PMID:9792484

Wientjes, C J; Grossman, P; Gaillard, A W

1998-09-01

281

Linking the Development of Ventilator-Induced Injury to Mechanical Function in the Lung  

PubMed Central

Management of ALI/ARDS involves supportive ventilation at low tidal volumes (Vt) to minimize the rate at which ventilator induced lung injury (VILI) develops while the lungs heal. However, we currently have few details to guide the minimization of VILI in the ALI/ARDS patient. The goal of the present study was to determine how VILI progresses with time as a function of the manner in which the lung is ventilated in mice. We found that the progression of VILI caused by over-ventilating the lung at a positive end-expiratory pressure of zero is accompanied by progressive increases in lung stiffness as well as the rate at which the lung derecruits over time. We were able to accurately recapitulate these findings in a computational model that attributes changes in the dynamics of recruitment and derecruitment to two populations of lung units. One population closes over a time scale of minutes following a recruitment maneuver and the second closes in a matter of seconds or less, with the relative sizes of the two populations changing as VILI develops. This computational model serves as a basis from which to link the progression of VILI to changes in lung mechanical function.

Smith, Bradford J.; Grant, Kara A.; Bates, Jason H. T.

2012-01-01

282

Mechanical ventilation and the total artificial heart: optimal ventilator trigger to avoid post-operative autocycling - a case series and literature review  

Microsoft Academic Search

Many patients with end-stage cardiomyopathy are now being implanted with Total Artificial Hearts (TAHs). We have observed individual cases of post-operative mechanical ventilator autocycling with a flow trigger, and subsequent loss of autocycling after switching to a pressure trigger. These observations prompted us to do a retrospective review of all TAH devices placed at our institution between August 2007 and

Allen B Shoham; Bhavesh Patel; Francisco A Arabia; Michael J Murray

2010-01-01

283

Effects of surfactant depletion on regional pulmonary metabolic activity during mechanical ventilation  

PubMed Central

Inflammation during mechanical ventilation is thought to depend on regional mechanical stress. This can be produced by concentration of stresses and cyclic recruitment in low-aeration dependent lung. Positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) allows for noninvasive assessment of regional metabolic activity, an index of neutrophilic inflammation. We tested the hypothesis that, during mechanical ventilation, surfactant-depleted low-aeration lung regions present increased regional 18F-FDG uptake suggestive of in vivo increased regional metabolic activity and inflammation. Sheep underwent unilateral saline lung lavage and were ventilated supine for 4 h (positive end-expiratory pressure = 10 cmH2O, tidal volume adjusted to plateau pressure = 30 cmH2O). We used PET scans of injected 13N-nitrogen to compute regional perfusion and ventilation and injected 18F-FDG to calculate 18F-FDG uptake rate. Regional aeration was quantified with transmission scans. Whole lung 18F-FDG uptake was approximately two times higher in lavaged than in nonlavaged lungs (2.9 ± 0.6 vs. 1.5 ± 0.3 10?3/min; P < 0.05). The increased 18F-FDG uptake was topographically heterogeneous and highest in dependent low-aeration regions (gas fraction 10–50%, P < 0.001), even after correction for lung density and wet-to-dry lung ratios. 18F-FDG uptake in low-aeration regions of lavaged lungs was higher than that in low-aeration regions of nonlavaged lungs (P < 0.05). This occurred despite lower perfusion and ventilation to dependent regions in lavaged than nonlavaged lungs (P < 0.001). In contrast, 18F-FDG uptake in normally aerated regions was low and similar between lungs. Surfactant depletion produces increased and heterogeneously distributed pulmonary 18F-FDG uptake after 4 h of supine mechanical ventilation. Metabolic activity is highest in poorly aerated dependent regions, suggesting local increased inflammation.

de Prost, Nicolas; Costa, Eduardo L.; Wellman, Tyler; Musch, Guido; Winkler, Tilo; Tucci, Mauro R.; Harris, R. Scott; Venegas, Jose G.

2011-01-01

284

Nutritional depletion in patients on long-term oxygen therapy and\\/or home mechanical ventilation  

Microsoft Academic Search

The purpose of this study was to estimate the prevalence of malnutrition in outpatients on long-term oxygen therapy or home mechanical ventilation, to determine the relationships between malnutrition and impairment\\/disability and smoking and also to identify relevant tools for routine nutritional assessment. In 744 patients (M:F 1.68, aged 65¡15 yrs) with chronic obstructive pulmonary disease (COPD, 40%), restrictive disorders (27%),

N. J. M. Cano; H. Roth; I. Court-Fortune; L. Cynoberz; M. Gerard-Boncompain; J. P. Laaban; J. C. Melchior; C. Pichard; J. C. Raphael; C. M. Pison

2002-01-01

285

Delivery of hyperbaric oxygen therapy to critically Ill, mechanically ventilated children  

Microsoft Academic Search

Purpose:The purpose of this article is (1) to describe our method of mechanical ventilation and monitoring of critically ill children during administration of hyperbaric oxygen therapy (HBO2) in a multiplace chamber; and (2) to review the complications they experienced during transport to the HBO2 chamber and HBO2 treatment.Materials and Methods:A case series from a universitya-ffiliated children's hospital and regional hyperbaric

Heather T. Keenan; Susan L. Bratton; Diane M. Norkool; Thomas V. Brogan; Neil B. Hampson

1998-01-01

286

Respiratory mechanics in rabbits ventilated with different tidal volumes.  

PubMed

Respiratory mechanics was studied in 11 rabbits at tidal volumes (VT) of 6.7, 10, and 20 ml/kg. Flow interruptions were performed during the full respiratory cycle. The viscoelastic pressure (Pve) was measured as the dynamic elastic pressure (Pel(dyn)) after flow cessation minus the static elastic pressure (Pel(st)). Static elastic and viscoelastic parameters were determined with numerical technique. Static hysteresis was minimal even at large VT. The Pel(st)-V curve was linear at small VT and in 6 animals at moderate VT. In 5 animals at moderate VT and in all animals at large VT, a linear segment with constant compliance was followed by a segment with decreasing compliance. The Pve-V curve could be described with a linear model only at small VT. A non-linear model was needed at increased VT. Compliance increased with VT. Both static and viscoelastic behaviours were linear up to larger volume ranges at large VT compared to moderate VT. PMID:9017849

Svantesson, C; John, J; Taskar, V; Evander, E; Jonson, B

1996-12-01

287

Numerical modeling and analysis of the environment in a mechanically ventilated greenhouse  

NASA Astrophysics Data System (ADS)

Multi-span Greenhouse cooling in summer is always a problem for the greenhouse industry in china, to solve this, the key is to accurately predict the distribution and change of greenhouse environment. At present, the influence of mechanical ventilation about a Venlo-type glass greenhouse on environment has not been reported. The environment model, which takes into account solar radiation, is modeled and the temperature change & distribution is numerically simulated in a mechanically ventilated greenhouse using CFD(Computational Fluid Dynamics),then the velocities and temperatures at key points are measured in a Venlo-type greenhouse. By comparing, the velocity error and the relative error is controlled in 0.08m/s and 7% , respectively. and the temperature error and the relative error is controlled in 2 degrees and 5% expect the individual, respectively. Although the values between simulated and measured have some errors, the curve trend shows that CFD simulation on the mechanical ventilation is effective. It will provide a theoretical basis on greenhouse structure optimization and energy saving in future.

Wu, Fei-Qing; Zhang, Li-Bin; Xu, Fang; Ai, Qing-Lin; Chen, Jiao-Liao

2009-07-01

288

Feasibility and reliability of an automated controller of inspired oxygen concentration during mechanical ventilation  

PubMed Central

Introduction Hypoxemia and high fractions of inspired oxygen (FiO2) are concerns in critically ill patients. An automated FiO2 controller based on continuous oxygen saturation (SpO2) measurement was tested. Two different SpO2-FiO2 feedback open loops, designed to react differently based on the level of hypoxemia, were compared. The results of the FiO2 controller were also compared with a historical control group. Methods The system measures SpO2, compares with a target range (92% to 96%), and proposes in real time FiO2 settings to maintain SpO2 within target. In 20 patients under mechanical ventilation, two different FiO2-SpO2 open loops were applied by a dedicated research nurse during 3 hours, each in random order. The times spent in and outside the target SpO2 values were measured. The results of the automatic controller were then compared with a retrospective control group of 30 ICU patients. SpO2-FiO2 values of the control group were collected over three different periods of 6 hours. Results Time in the target range was higher than 95% with the controller. When the 20 patients were separated according to the median PaO2/FiO2 (160(133-176) mm Hg versus 239(201-285)), the loop with the highest slope was slightly better (P?=?0.047) for the more-hypoxemic patients. Hyperoxemia and hypoxemia durations were significantly shorter with the controller compared with usual care: SpO2 target range was reached 90% versus 24%, 27% and 32% (P?care.

2014-01-01

289

Daily sedative interruption versus intermittent sedation in mechanically ventilated critically ill patients: a randomized trial  

PubMed Central

Background Daily sedative interruption and intermittent sedation are effective in abbreviating the time on mechanical ventilation. Whether one is superior to the other has not yet been determined. Our aim was to compare daily interruption and intermittent sedation during the mechanical ventilation period in a low nurse staffing ICU. Methods Adult patients expected to need mechanical ventilation for more than 24 hours were randomly assigned, in a single center, either to daily interruption of continuous sedative and opioid infusion or to intermittent sedation. In both cases, our goal was to maintain a Sedation Agitation Scale (SAS) level of 3 or 4; that is patients should be calm, easily arousable or awakened with verbal stimuli or gentle shaking. Primary outcome was ventilator-free days in 28 days. Secondary outcomes were ICU and hospital mortality, incidence of delirium, nurse workload, self-extubation and psychological distress six months after ICU discharge. Results A total of 60 patients were included. There were no differences in the ventilator-free days in 28 days between daily interruption and intermittent sedation (median: 24 versus 25 days, P?=?0.160). There were also no differences in ICU mortality (40 versus 23.3%, P?=?0.165), hospital mortality (43.3 versus 30%, P?=?0.284), incidence of delirium (30 versus 40%, P?=?0.472), self-extubation (3.3 versus 6.7%, P?=?0.514), and psychological stress six months after ICU discharge. Also, the nurse workload was not different between groups, but it was reduced on day 5 compared to day 1 in both groups (Nurse Activity Score (NAS) in the intermittent sedation group was 54 on day 1 versus 39 on day 5, P?ventilator-free days in 28 days between both groups. Intermittent sedation was associated with lower sedative and opioid doses. Trial registration ClinicalTrials.gov Identifier: NCT00824239.

2014-01-01

290

Outcomes of a ventilator-associated pneumonia bundle on rates of ventilator-associated pneumonia and other health care-associated infections in a long-term acute care hospital setting.  

PubMed

Long-term trends in ventilator-associated pneumonia (VAP) rates, and other health care-associated infections, were examined prior to, during, and after introduction of a VAP bundle in a long-term acute care hospital setting. VAP incidence rate declined in a step-wise fashion and reached a null value. Incidence rates of bacteremia from any cause declined in a similar fashion. The incidence rates of vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus colonization or infection rates also decreased, but that of Clostridium difficile infection did not. VAP in the long-term acute care hospital setting can be controlled over time with implementation of Centers for Disease Control and Prevention-based VAP bundle. This outcome also may decrease certain other health care-associated infections. PMID:24773791

Sulis, Carol A; Walkey, Allan J; Abadi, Yafet; Campbell Reardon, Christine; Joyce-Brady, Martin

2014-05-01

291

SpO2 and PetCO2 signal analysis in closed-loop mechanical lung ventilation systems  

Microsoft Academic Search

Employment of SpO2 and PetCO2 signal analysis for setting parameters of mechanical lung ventilation in closed-loop systems is considered. Results of time-frequency representation of such signals are presented and discussed.

Oleg Bodilovskyi; Anton Popov; Mykhailo Zakorchevnyi

2012-01-01

292

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

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.

Hernandez-Jimenez, Claudia; Garcia-Torrentera, Rogelio; Olmos-Zuniga, J. Raul; Jasso-Victoria, Rogelio; Gaxiola-Gaxiola, Miguel O.; Baltazares-Lipp, Matilde; Gutierrez-Gonzalez, Luis H.

2014-01-01

293

Evaluation of a New Index of Mechanical Ventilation Weaning: The Timed Inspiratory Effort.  

PubMed

PURPOSE: The performance of most indices used to predict ventilator weaning outcomes remains below expectation. The purpose of this study was to evaluate a new weaning index, the timed inspiratory effort (TIE) index, which is based on the maximal inspiratory pressure and the occlusion time required to reach it. METHODS: This observational prospective study included patients undergoing mechanical ventilation. Patients ready to be weaned had their TIE index and 6 previously reported indices recorded. The primary end point was the overall predictive performance of the studied weaning indices (area under the receiver operating characteristic curves [AUCs]). The secondary end points were sensitivity, specificity, positive predictive value, and negative predictive value. P values <.05 were considered significant. RESULTS: From the 128 initially screened patients, the 103 patients selected for the study included 45 women and 58 men (mean age 60.8 ± 19.8 years). In all, 60 patients were weaned, 43 were not weaned, and 32 died during the study period. Tracheotomy was necessary in 61 patients. The mean duration of mechanical ventilation was 17.5 ± 17.3 days. The AUC of 3 weaning predictors (the TIE index, the integrative weaning index, and the frequency-to-tidal volume [f/Vt] ratio index) was higher than the other indices. The TIE index had the largest AUC. CONCLUSION: The TIE index performed better than the best weaning indices used in clinical practice. PMID:23753238

de Souza, Leonardo Cordeiro; Guimarães, Fernando Silva; Lugon, Jocemir Ronaldo

2013-04-10

294

Candidemia in the critically ill: initial therapy and outcome in mechanically ventilated patients  

PubMed Central

Background Mortality among critically ill patients with candidemia is very high. We sought to determine whether the choice of initial antifungal therapy is associated with survival among these patients, using need for mechanical ventilatory support as a marker of critical illness. Methods Cohort analysis of outcomes among mechanically ventilated patients with candidemia from the 24 North American academic medical centers contributing to the Prospective Antifungal Therapy (PATH) Alliance registry. Patients were included if they received either fluconazole or an echinocandin as initial monotherapy. Results Of 5272 patients in the PATH registry at the time of data abstraction, 1014 were ventilated and concomitantly had candidemia, with 689 eligible for analysis. 28-day survival was higher among the 374 patients treated initially with fluconazole than among the 315 treated with an echinocandin (66% versus 51%, P?ventilated patients with candidemia, those receiving fluconazole as initial monotherapy were significantly more likely to survive than those treated with an echinocandin. This difference persisted after adjustment for non-treatment factors.

2013-01-01

295

Advanced glycation endproducts in sepsis and mechanical ventilation: extra or leading man?  

PubMed Central

Advanced glycation endproducts (AGEs) are primarily known as a complication in diabetic patients through their mediation of the inflammatory response. However, a variety of studies have demonstrated enhanced formation of AGEs in cardiovascular disorders. Despite the large number of AGEs produced during the Maillard reaction, recent focus is on the major non-crosslinking AGE N?-carboxymethyllysine. Kneyber and colleagues focused on sepsis-induced cardiac dysfunction and investigated whether myocardial inflammation is associated with enhanced cardiac AGE deposition and whether this is further enhanced by mechanical ventilation. They showed that both conditions are associated with enhanced AGE deposition and myocardial inflammation. Therefore, AGEs may participate in the inflammatory response related to cardiac dysfunction in critically ill patients. Moreover, life-saving ventilation stimulates AGE formation in these patients. This interesting study raises the question of whether AGEs in critically ill patients are a driving force of the disease.

2009-01-01

296

Weaning from mechanical ventilation followed at home with the aid of a telemedicine program.  

PubMed

We describe the use of telemedicine in support of weaning from invasive mechanical ventilation on a 63-year-old woman of at home by means of a telepneumology program (TPP). Under telephone assistance of a pulmonologist and a TPP nurse tutor, the pulsed arterial saturimetric (pSaT), heart rate (HR), breathing pattern tracing monitoring transmitted via a home telephone line and the aid of the caregiver, the patient was able to maintain diurnal spontaneous breathing after 24 spontaneous breathing trial (SBT) steps twice daily. The duration of each SBT period progressively increased starting from 30 minutes up to 8 hours. This case report shows that many patients at home on ventilators could possibly be weaned through the use of remote monitoring and call center response, with only family/caregivers on-site. PMID:17848112

Vitacca, Michele; Guerra, Alberto; Assoni, Giuliano; Pizzocaro, Piera; Marchina, Lucia; Scalvini, Simonetta; Balbi, Bruno

2007-08-01

297

Recurrence plots and Shannon entropy for a dynamical analysis of asynchronisms in noninvasive mechanical ventilation.  

PubMed

Recurrence plots were introduced to quantify the recurrence properties of chaotic dynamics. Hereafter, the recurrence quantification analysis was introduced to transform graphical interpretations into statistical analysis. In this spirit, a new definition for the Shannon entropy was recently introduced in order to have a measure correlated with the largest Lyapunov exponent. Recurrence plots and this Shannon entropy are thus used for the analysis of the dynamics underlying patient assisted with a mechanical noninvasive ventilation. The quality of the assistance strongly depends on the quality of the interactions between the patient and his ventilator which are crucial for tolerance and acceptability. Recurrence plots provide a global view of these interactions and the Shannon entropy is shown to be a measure of the rate of asynchronisms as well as the breathing rhythm. PMID:17411251

Rabarimanantsoa, H; Achour, L; Letellier, C; Cuvelier, A; Muir, J-F

2007-03-01

298

Recurrence plots and Shannon entropy for a dynamical analysis of asynchronisms in noninvasive mechanical ventilation  

NASA Astrophysics Data System (ADS)

Recurrence plots were introduced to quantify the recurrence properties of chaotic dynamics. Hereafter, the recurrence quantification analysis was introduced to transform graphical interpretations into statistical analysis. In this spirit, a new definition for the Shannon entropy was recently introduced in order to have a measure correlated with the largest Lyapunov exponent. Recurrence plots and this Shannon entropy are thus used for the analysis of the dynamics underlying patient assisted with a mechanical noninvasive ventilation. The quality of the assistance strongly depends on the quality of the interactions between the patient and his ventilator which are crucial for tolerance and acceptability. Recurrence plots provide a global view of these interactions and the Shannon entropy is shown to be a measure of the rate of asynchronisms as well as the breathing rhythm.

Rabarimanantsoa, H.; Achour, L.; Letellier, C.; Cuvelier, A.; Muir, J.-F.

2007-03-01

299

Individuality of breathing patterns in patients under noninvasive mechanical ventilation evidenced by chaotic global models  

NASA Astrophysics Data System (ADS)

Autonomous global models based on radial basis functions were obtained from data measured from patients under noninvasive mechanical ventilation. Some of these models, which are discussed in the paper, turn out to have chaotic or quasi-periodic solutions, thus providing a first piece of evidence that the underlying dynamics of the data used to estimate the global models are likely to be chaotic or, at least, have a chaotic component. It is explicitly shown that one of such global models produces attractors characterized by a Horseshoe map, two models produce toroidal chaos, and one model produces a quasi-periodic regime. These topologically inequivalent attractors evidence the individuality of breathing profiles observed in patient under noninvasive ventilation.

Letellier, Christophe; Rodrigues, Giovani G.; Muir, Jean-François; Aguirre, Luis A.

2013-03-01

300

Rationale and study design of ViPS - variable pressure support for weaning from mechanical ventilation: study protocol for an international multicenter randomized controlled open trial  

PubMed Central

Background In pressure support ventilation (PSV), a non-variable level of pressure support is delivered by the ventilator when triggered by the patient. In contrast, variable PSV delivers a level of pressure support that varies in a random fashion, introducing more physiological variability to the respiratory pattern. Experimental studies show that variable PSV improves gas exchange, reduces lung inflammation and the mean pressure support, compared to non-variable PSV. Thus, it can theoretically shorten weaning from the mechanical ventilator. Methods/design The ViPS (variable pressure support) trial is an international investigator-initiated multicenter randomized controlled open trial comparing variable vs. non-variable PSV. Adult patients on controlled mechanical ventilation for more than 24 hours who are ready to be weaned are eligible for the study. The randomization sequence is blocked per center and performed using a web-based platform. Patients are randomly assigned to one of the two groups: variable PSV or non-variable PSV. In non-variable PSV, breath-by-breath pressure support is kept constant and targeted to achieve a tidal volume of 6 to 8 ml/kg. In variable PSV, the mean pressure support level over a specific time period is targeted at the same mean tidal volume as non-variable PSV, but individual levels vary randomly breath-by-breath. The primary endpoint of the trial is the time to successful weaning, defined as the time from randomization to successful extubation. Discussion ViPS is the first randomized controlled trial investigating whether variable, compared to non-variable PSV, shortens the duration of weaning from mechanical ventilation in a mixed population of critically ill patients. This trial aims to determine the role of variable PSV in the intensive care unit. Trial registration clinicaltrials.gov NCT01769053

2013-01-01

301

Mechanical Ventilation  

MedlinePLUS

... when you are unable to make decisions yourself. Advance directives are ways to also put your wishes in ... and social workers can provide information about an advance directive form. You can also obtain information on advance ...

302

Nasal ventilation.  

PubMed Central

Nasal intermittent positive pressure ventilation is likely to have an increasing role in the management of acute ventilatory failure, weaning, and chronic ventilatory problems. Further improvements in ventilator and mask design will be seen. Appropriate application is likely to reduce both mortality and admissions to intensive care, while domiciliary use can improve life expectancy and/or quality of life in chronic ventilatory disorders. As with any new technique, enthusiasm should not outweigh clear outcome information, and possible new indications should always be subject to careful assessment. Images Figure 2

Simonds, A. K.

1998-01-01

303

Drug-resistant ventilator associated pneumonia in a tertiary care hospital in Saudi Arabia  

PubMed Central

BACKGROUND: There is a wide geographic and temporal variability of bacterial resistance among microbial causes of ventilator-associated pneumonia (VAP). The contribution of multi-drug resistant (MDR) pathogens to the VAP etiology in Saudi Arabia was never studied. We sought to examine the extent of multiple-drug resistance among common microbial causes of VAP. MATERIALS AND METHODS: We conducted a retrospective susceptibility study in the adult intensive care unit (ICU) of King Abdulaziz Medical City, Riyadh, Saudi Arabia. Susceptibility results of isolates from patients diagnosed with VAP between October 2004 and June 2009 were examined. The US National Healthcare Safety Network definition of MDR was adopted. RESULTS: A total of 248 isolates including 9 different pathogens were included. Acinetobacter spp. was highly (60-89%) resistant to all tested antimicrobials, including carbapenems (three- and four-class MDR prevalence were 86% and 69%, respectively). Pseudomonas aeruginosa was moderately (13-31%) resistant to all tested antimicrobials, including antipseudomonal penicillins (three- and four-class MDR prevalence were 13% and 10%, respectively). With an exception of ampicillin (fully resistant), Klebsiella spp. had low (0-13%) resistance to other tested antimicrobials with no detected MDR. Staphylococcus aureus was fully susceptible to vancomycin with 42% resistance to oxacillin. There were significant increasing trends of MDR Acinetobacter spp. however not P. aeruginosa during the study. Resistant pathogens were associated with worse profile of ICU patients but not patients’ outcomes. CONCLUSION: Acinetobacter in the current study was an increasingly resistant VAP-associated pathogen more than seen in many parts of the world. The current finding may impact local choice of initial empiric antibiotics.

Balkhy, Hanan H.; El-Saed, Aiman; Maghraby, Rana; Al-Dorzi, Hasan M.; Khan, Raymond; Rishu, Asgar H.; Arabi, Yaseen M.

2014-01-01

304

Pathogenic analysis of sputum from ventilator-associated pneumonia in a pediatric intensive care unit  

PubMed Central

Ventilator-associated pneumonia (VAP) is a common and sometimes fatal complication in pediatric intensive care units (PICU). The aim of our study was to characterize the distribution and drug susceptibility of the pathogens isolated from the sputum of patients with VAP in the PICU of our hospital and to provide support to the administration of antibiotics early and reasonably in the clinic. Our study was conducted between January 2007 and December 2011 at the PICU of the Children’s Hospital of Zhejiang University School of Medicine. The endotracheal aspirates were collected and transported to a microbiology laboratory within 15 min. The pathogens were routinely analyzed and identified with Vitek 60 and Kirby-Bauer disk diffusion methods. Among the 121 VAP patients, 127 pathogenic strains were isolated from sputum specimens. Gram-negative and gram-positive bacteria and fungi accounted for 64.57% (82/127), 29.92% (38/127) and 5.51% (7/127), respectively. Acinetobacter baumannii (25.61%), Escherichia coli (20.27%), Stenotrophomonas maltophilia (20.27%), Klebsiella pneumoniae (16.22%) and Pseudomonas aeruginosa (9.46%) were frequently identified isolates among gram-negative bacteria. Staphylococci were susceptible to vancomycin and linezolid. All fungi were sensitive to the antimicrobial agents. The gram-negative bacteria were more prevalent than gram-positive bacteria and fungi in VAP and demonstrated a higher drug resistance. It is important to administer antimicrobial agents early and reasonably for children with VAP. Knowledge of antibiotic resistance and the characteristics of drug resistance is important for VAP prophylaxis and treatment.

NING, BO-TAO; ZHANG, CHEN-MEI; LIU, TAO; YE, SHENG; YANG, ZI-HAO; CHEN, ZHEN-JIE

2013-01-01

305

Viral-Reactivated Pneumonia during Mechanical Ventilation: Is There Need for Antiviral Treatment?  

PubMed Central

Respiratory viruses are not a common cause of ventilator-associated pneumonia (VAP). Herpesviridae [Herpes simplex virus (HSV) and cytomegalovirus (CMV)] are detected frequently in the lower respiratory tract of ventilated patients. HSV is detected between days 7 and 14 of invasive mechanical ventilation (IMV); presence of the virus does not necessarily imply pathogenicity, but the association with adverse clinical outcomes supports the hypothesis of a pathogenic role in a variable percentage of patients. Bronchopneumonitis associated with HSV should be considered in patients with prolonged IMV, reactivation with herpetic mucocutaneous lesions and those belonging to a risk population with burn injuries or acute lung injury. Reactivation of CMV is common in critically ill patients and usually occurs between days 14 and 21 in patients with defined risk factors. The potential pathogenic role of CMV seems clear in patients with acute lung injury and persistent respiratory failure in whom there is no isolation of bacterial agent as a cause of VAP. The best diagnostic test is not defined although lung biopsies should be considered in addition to the usual methods before starting specific treatment. The role of mimivirus is uncertain and is yet to be defined, but the serologic evidence of this new virus in the context of VAP appears to be associated with adverse clinical outcomes.

Lopez-Giraldo, Alejandra; Sialer, Salvador; Esperatti, Mariano; Torres, Antoni

2011-01-01

306

Proportional mechanical ventilation through PWM driven on\\/off solenoid valve  

Microsoft Academic Search

Proportional strategies for artificial ventilation are the most recent form of synchronized partial ventilatory assistance and intra-breath control techniques available in clinical practice. Currently, the majority of commercial ventilators allowing proportional ventilation uses proportional valves to generate the flow rate pattern. This paper proposes on-off solenoid valves for proportional ventilation given their small size, low cost and short switching time,

I. Sardellitti; S. Cecchini; S. Silvestri; D. G. Caldwell

2010-01-01

307

Experimental critical care in ventilated rats: Effect of hypercapnia on arterial oxygen-carrying capacity  

Microsoft Academic Search

Purpose: We have previously demonstrated an increased arterial o2-carrying capacity in normal ventilated dogs subjected to both acute and prolonged exogenous hypercapnia. In the present study, we tested if arterial hypercapnia, during controlled ventilation, can increase 02-carrying capacity also in rats.Materials and Methods: Twenty young male Sprague Dawley rats were anesthetized (60 mg\\/kg pentobarbital), tracheostomized, intubated, and one femoral vein

Dan Torbati; Bala R. Totapally; Maria T. Camacho; Jack Wolfsdorf

1999-01-01

308

Temporal Disorganization of Circadian Rhythmicity and Sleep-Wake Regulation in Mechanically Ventilated Patients Receiving Continuous Intravenous Sedation  

PubMed Central

Objectives: Sleep is regulated by circadian and homeostatic processes and is highly organized temporally. Our study was designed to determine whether this organization is preserved in patients receiving mechanical ventilation (MV) and intravenous sedation. Design: Observational study. Setting: Academic medical intensive care unit. Patients: Critically ill patients receiving MV and intravenous sedation. Methods: Continuous polysomnography (PSG) was initiated an average of 2.0 (1.0, 3.0) days after ICU admission and continued ? 36 h or until the patient was extubated. Sleep staging and power spectral analysis were performed using standard approaches. We also calculated the electroencephalography spectral edge frequency 95% (SEF95), a parameter that is normally higher during wakefulness than during sleep. Circadian rhythmicity was assessed in 16 subjects through the measurement of aMT6s in urine samples collected hourly for 24-48 hours. Light intensity at the head of the bed was measured continuously. Measurements and Results: We analyzed 819.7 h of PSG recordings from 21 subjects. REM sleep was identified in only 2/21 subjects. Slow wave activity lacked the normal diurnal and ultradian periodicity and homeostatic decline found in healthy adults. In nearly all patients, SEF95 was consistently low without evidence of diurnal rhythmicity (median 6.3 [5.3, 7.8] Hz, n = 18). A circadian rhythm of aMT6s excretion was present in most (13/16, 81.3%) patients, but only 4 subjects had normal timing. Comparison of the SEF95 during the melatonin-based biological night and day revealed no difference between the 2 periods (P = 0.64). Conclusions: The circadian rhythms and PSG of patients receiving mechanical ventilation and intravenous sedation exhibit pronounced temporal disorganization. The finding that most subjects exhibited preserved, but phase delayed, excretion of aMT6s suggests that the circadian pacemaker of such patients may be free-running. Clinical Trial Information: Clinicaltrials.gov NCT01276652. Citation: Gehlbach BK; Chapotot F; Leproult R; Whitmore H; Poston J; Pohlman M; Miller A; Pohlman AS; Nedeltcheva A; Jacobsen JH; Hall JB; Van Cauter E. Temporal disorganization of circadian rhythmicity and sleep-wake regulation in mechanically ventilated patients receiving continuous intravenous sedation. SLEEP 2012;35(8):1105-1114.

Gehlbach, Brian K.; Chapotot, Florian; Leproult, Rachel; Whitmore, Harry; Poston, Jason; Pohlman, Mark; Miller, Annette; Pohlman, Anne S.; Nedeltcheva, Arlet; Jacobsen, John H.; Hall, Jesse B.; Van Cauter, Eve

2012-01-01

309

47 CFR 54.602 - Health care support mechanism.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Health care support mechanism. 54.602... Universal Service Support for Health Care Providers Defined Terms and Eligibility § 54.602 Health care support mechanism. (a)...

2013-10-01

310

A new adaptive controller for volume-controlled mechanical ventilation in small animals.  

PubMed

ABSTRACT Background: This study aimed to develop and evaluate an adaptive control system for volume-controlled ventilation (VCV) in small animals to guarantee accurate delivery of tidal volume (VT) in the presence of changes in lung mechanics. Methods: The adaptive control system to control the Harvard Inspira ventilator was designed and evaluated on a custom-made physical model during step changes of resistance and elastance of the respiratory system assessing difference in minute ventilation (?MVc) during convergence cycles (NC). The controller was then evaluated during conventional and variable volume VCV in rats with acute respiratory distress syndrome (ARDS) induced by intratracheal HCl (six animals/group), where the difference between desired and applied VT (dVT,d), its root-mean square error (RMSE) and relative deviation from target minute ventilation (?MV) were determined. Results: The controller showed fast convergence NC < 20 cycles with an acceptable ?MVC < 10% in simulations and nearly abolished dVT,d (VCV: 0.23 ± 0.1 mL to 0.0 ± 0.0 mL, P < .001 and vVCV: 0.05 ± 0.8 mL to 0.0 ± 0.0 mL, P < .001), significantly reduced RMSE (VCV: 0.23 ± 0.1 to 0.04 ± 0.01 mL, P < .001 and vVCV: 0.13 ± 0.04 to 0.08 ± 0.02 mL, P < .001) and ?MV (VCV: 11.6 ± 4.2 to 0.04 ± 0.15%, P < .001 and vVCV: -3 ± 3.8 to -0.35 ± 1.3 %, P < .001) in animal experiments. In VCV the improvement was more pronounced, due to reduced respiratory system elastance in this group (VCV: 5.6 cmH2O mL(-1) versus vVCV: 3.8 cmH2O mL(-1), P < .001). Conclusions: The new adaptive controller ensured accurate delivery of VT in VCV and proved valuable for mechanical ventilation of small animals especially in ARDS research. PMID:24712850

Huhle, Robert; Spieth, Peter M; Güldner, Andreas; Koch, Thea; Abreu, Marcelo Gama de

2014-04-01

311

Flow resistance of exhalation valves and positive end-expiratory pressure devices used in mechanical ventilation.  

PubMed

We studied the flow-impeding characteristics of the exhalation valves and PEEP attachments commonly used in mechanical ventilation. To characterize these devices, the pressure difference across each mechanism was measured at a series of constant flows (5 to 160 L/min), and resistance-related energy dissipation was measured using mechanical models of passive and active exhalation. At ambient end-expiratory pressure, an inflatable diaphragm (mushroom) design commonly used to valve exhalation presented resistance comparable to that of an endotracheal tube with an internal diameter of 5 mm. The valve's energy dissipation increased further as PEEP was applied. By comparison, the servo-actuated scissor valve we tested presented less resistance during the passive deflation experiment but impeded the early phase of active exhalation. Spring-loaded PEEP attachments were prohibitively resistive in comparison with alternative methods using an underwater tube, a water column, a weighted spirometer, or an inflatable diaphragm to raise end-expiratory pressure. We conclude that the exhalation valves and PEEP attachments currently available for clinical use present significant impedance to air flow. Such resistance within the exhalation pathway may be clinically important for patients supported by mechanical ventilation during the hyperpneic or weaning phases of their illness. PMID:3890641

Marini, J J; Culver, B H; Kirk, W

1985-06-01

312

Short-term outcome of mechanically ventilated infants weighing more than 2499 g at birth: a population based study.  

PubMed

Very little data exist describing the neonatal outcome of infants of birthweight 2500 g or more who require mechanical ventilation. Our aim was to collect population-based data on such infants in New South Wales (NSW), and to monitor their neonatal morbidity, mortality to 1 year of age and the associated risk factors. The study group (NICUS infants) comprised all 341 infants weighing > 2499 g who were admitted to the seven neonatal intensive care units in New South Wales and mechanically ventilated for 4 h or more between 1 January and 31 December, 1987. Two groups of infants emerged: those who were preterm and mostly had hyaline membrane disease, and term and post-term infants for whom the most common problem was 'perinatal asphyxia'. The most important factors associated with dying were a birthweight of over 3499 g (OR = 2.6; CI 1.03-6.6) and a 1 min Apgar score < 4 (OR = 4.8; CI 1.4-16.9). Study group mothers were significantly more likely than all NSW mothers to have had a spontaneous abortion in the previous pregnancy (P < 0.01), a pre-existing medical condition or an obstetric complication in this pregnancy, or a Caesarean section for this delivery (P < 0.001). This is the first population-based study of high-risk neonates without congenital anomalies to clearly document the worsening prognosis associated with a birthweight over 3499 g. Further research should be directed towards identifying prenatal and perinatal factors which might minimize the morbidity and mortality in this group of babies. PMID:8286156

Sutton, L; Bajuk, B; Duffy, B; Alexander, I; Arnold, J; Leslie, G; Henderson-Smart, D; John, E; Roberts, V; Berry, A

1993-12-01

313

[Hyperbaric oxygenation influence on intracranial pressure in patents with intracranial hemorrhage receiving mechanical ventilation].  

PubMed

The study focuses on hyperbaric oxygenation (HBO) influence on the intracranial pressure (ICP) in patients with intracranial hemorrhages. Forty eight hyperbaric oxygenation sessions in 21 mechanically ventilated patients with intracranial hemorrhages were analyzed. HBO was accompanied by ICP increase in 31,3% of cases. ICP was stable during 54,2% of sessions and decreased during 14,5% of sessions. We didn 't find any relation between ICP dynamics and PaCO2. ICP increase correlated with mean BP dynamics which growth by 11% and more was an indicator of intracranial hypertension. PMID:21957623

Aleshchenko, E I; Romasenko, M V; Petrikov, S S; Levina, O A; Krylov, V V

2011-01-01

314

A dynamic morphometric model of the normal lung for studying expiratory flow limitation in mechanical ventilation.  

PubMed

A nonlinear dynamic morphometric model of breathing mechanics during artificial ventilation is described. On the basis of the Weibel symmetrical representation of the tracheo-bronchial tree, the model accurately accounts for the geometrical and mechanical characteristics of the conductive zone and packs the respiratory zone into a viscoelastic Voigt body. The model also accounts for the main mechanisms limiting expiratory flow (wave speed limitation and viscous flow limitation), in order to reproduce satisfactorily, under dynamic conditions, the expiratory flow limitation phenomenon occurring in normal subjects when the difference between alveolar pressure and tracheal pressure (driving pressure) is high. Several expirations characterized by different levels of driving pressure are simulated and expiratory flow limitation is detected by plotting the isovolume pressure-flow curves. The model is used to study the time course of resistance and total cross-sectional area as well as the ratio of fluid velocity to wave speed (speed index), in conductive airway generations. The results highlight that the coupling between dissipative pressure losses and airway compliance leads to onset of expiratory flow limitation in normal lungs when driving pressure is increased significantly by applying a subatmospheric pressure to the outlet of the ventilator expiratory channel; wave speed limitation becomes predominant at still higher driving pressures. PMID:15909658

Barbini, Paolo; Brighenti, Chiara; Cevenini, Gabriele; Gnudi, Gianni

2005-04-01

315

Independent living with Duchenne muscular dystrophy and home mechanical ventilation in areas of Japan with insufficient national welfare services  

PubMed Central

In Japan, there is no national 24-hour home care system for people with severe impairments. Despite this fact, a small number of people with Duchenne muscular dystrophy on home mechanical ventilation pursue independent living. Therefore, our aim was to better understand the process by which these individuals arrived at this goal for independence (i.e., choosing to live at home in Japan instead of in special sanatoriums that provide sufficient support and care). Twenty-one participants were interviewed in 2011 and 2013. The interviews were recorded, transcribed, and analysed following a grounded theory approach. These individuals placed particular emphasis on their personal choice regarding where and how they live as well as on whom they depend. Therefore, the core element underlying participants’ goals for independent living was self-reliant independency. To improve their social inclusion, the strategies used by the participants to retain their autonomy in an underdeveloped Japanese welfare system by establishing relationships with people in their communities can prevent them from experiencing social isolation. This could serve as an example to their counterparts in other countries.

Yamaguchi, Miku; Suzuki, Machiko

2013-01-01

316

Neonatal ventilators: how do they differ?  

PubMed

Remarkable technological advances over the past two decades have brought dramatic changes to the neonatal intensive care unit. Microprocessor-based mechanical ventilation has replaced time-cycled, pressure-limited, intermittent mandatory ventilation with almost limitless options for the management of respiratory failure in the prematurely born infant. Unfortunately, much of the infusion of technology occurred before the establishment of a convincing evidence base. This review focuses on the basic principles of mechanical ventilation, nomenclature and the characteristics of both conventional and high-frequency devices. PMID:19399015

Donn, S M

2009-05-01

317

Cost-consequence analysis of remifentanil-based analgo-sedation vs. conventional analgesia and sedation for patients on mechanical ventilation in the Netherlands  

Microsoft Academic Search

Introduction  Hospitals are increasingly forced to consider the economics of technology use. We estimated the incremental cost-consequences\\u000a of remifentanil-based analgo-sedation (RS) vs. conventional analgesia and sedation (CS) in patients requiring mechanical ventilation\\u000a (MV) in the intensive care unit (ICU), using a modelling approach.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  A Markov model was developed to describe patient flow in the ICU. The hourly probabilities to move from

Maiwenn J Al; Leona Hakkaart; Siok Swan Tan; Jan Bakker

2010-01-01

318

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

PubMed

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 ?l/g (aggressive) tidal volume (Tv), or for 8 hours with 8 ?l/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. PMID:23980609

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

2013-12-01

319

Recovery of Diaphragm Function following Mechanical Ventilation in a Rodent Model  

PubMed Central

Background Mechanical ventilation (MV) induces diaphragmatic muscle fiber atrophy and contractile dysfunction (ventilator induced diaphragmatic dysfunction, VIDD). It is unknown how rapidly diaphragm muscle recovers from VIDD once spontaneous breathing is restored. We hypothesized that following extubation, the return to voluntary breathing would restore diaphragm muscle fiber size and contractile function using an established rodent model. Methods Following 12 hours of MV, animals were either euthanized or, after full wake up, extubated and returned to voluntary breathing for 12 hours or 24 hours. Acutely euthanized animals served as controls (each n?=?8/group). Diaphragmatic contractility, fiber size, protease activation, and biomarkers of oxidative damage in the diaphragm were assessed. Results 12 hours of MV induced VIDD. Compared to controls diaphragm contractility remained significantly depressed at 12 h after extubation but rebounded at 24 h to near control levels. Diaphragmatic levels of oxidized proteins were significantly elevated after MV (p?=?0.002) and normalized at 24 hours after extubation. Conclusions These findings indicate that diaphragm recovery from VIDD, as indexed by fiber size and contractile properties, returns to near control levels within 24 hours after returning to spontaneous breathing. Besides the down-regulation of proteolytic pathways and oxidative stress at 24 hours after extubation further repairing mechanisms have to be determined.

Bruells, Christian S.; Bergs, Ingmar; Rossaint, Rolf; Du, Jun; Bleilevens, Christian; Goetzenich, Andreas; Weis, Joachim; Wiggs, Michael P.; Powers, Scott K.; Hein, Marc

2014-01-01

320

[Role of invasive and non-invasive ventilation in the treatment of acute respiratory failure].  

PubMed

Mechanical ventilation is the most common invasive treatment for acute respiratory failure in intensive care units. According to non-intensivist clinicians, ventilation could be considered as a therapy for blood gas exchange, even though positive pressure ventilation can be extremely dangerous for injured lung tissue. Despite constant advances in ventilation software and modalities, aimed at optimizing patient/ventilator adjustment, the scientific community has addressed major attention in new protective strategies to ventilate the lung, trying to prevent and reduce life-threatening iatrogenic injuries that may derive from inappropriate use of mechanical ventilation. In this review we describe the main ventilation techniques as well as new emerging methodologies. The physiological bases on which the acute respiratory distress syndrome network has significantly changed the strategy for ventilation in patients with acute respiratory distress syndrome are also discussed. Non-invasive ventilation, including both continuous positive airway pressure and pressure support ventilation, is considered the gold standard for chronic obstructive pulmonary disease exacerbations. There is an increasing interest in the clinical use of non-invasive ventilation outside intensive care units. Although many studies have analyzed risks and benefits of non-invasive ventilation in the intensive care setting, feasibility and organization processes to perform this technique in the non-intensive wards, by preserving efficacy and safety, need to be debated. PMID:20380337

Colombo, Sergio; Zangrillo, Alberto

2010-01-01

321

Transient Respiratory Sensitivity to Small Mechanical Stimuli Assessed by Spontaneously Breathing on a Ventilator.  

National Technical Information Service (NTIS)

Respiratory response to repeated sequences of mild negative inspiratory pressure (NIP) was investigated. Ten healthy male subjects were spontaneously breathing on a Siemens Servo Ventilator. The ventilator delivered the NIP loading (-2 cm H20 during 30 se...

L. G. Hellstrom J. Persson

2001-01-01

322

Liquid Ventilation  

PubMed Central

Mammals have lungs to breathe air and they have no gills to breath liquids. When the surface tension at the air-liquid interface of the lung increases, as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV) is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen, as the inert carrier of oxygen and carbon dioxide offers a number of theoretical advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. The potential for multiple clinical applications for liquid-assisted ventilation will be clarified and optimized in future.

Tawfic, Qutaiba A.; Kausalya, Rajini

2011-01-01

323

[Measurement of functional residual capacity by nitrogen washout during mechanical ventilation].  

PubMed

A medical gas analyzer AMIS 2000 SP, which is a mass spectrometer, incorporating a fractional residual capacity (FRC) measuring program based on a nitrogen washout method, has been introduced recently. The purpose of this study was to assess the reliability and the reproductivity of the FRC measuring system in a clinical situation. FRC was measured by this system connected to a ventilator (Bennet 7200ae). Our study examined; 1) the accuracy of the measurement using a syringe. 2) the difference in two consecutive measurements in the same subject during mechanical ventilation, and 3) the correlation between the measured and the predicted value calculated with Gorldman's formula in 18 subjects during ventilation. The first study has showed an excellent correlation (y = 0.953x + 0.092, r = 0.996, P < 0.001) or y = 0.909x + 0.132 (r = 0.999, P < 0.001) with a tidal volume of 400 ml or 500 ml, respectively) between the measured value and the syringe capacity. Reproductivity was proved by the linear regression (y = 0.977x + 0.024, r = 0.998, P < 0.001) between the two consecutive measurements. A good correlation was shown between the measured values and the predicted values (y = 0.656x - 0.415, r = 0.849, P < 0.0001). These results showed good reliability and reproductivity of our FRC measuring system. It is concluded that the FRC measurements using AMIS2000SP system can be used in clinical respiratory managements in ICU. PMID:9513330

Nomura, T; Saito, Y; Ogawa, H; Akata, N; Nishino, Y; Kosaka, Y

1998-02-01

324

Clinical review: Helmet and non-invasive mechanical ventilation in critically ill patients  

PubMed Central

Non-invasive mechanical ventilation (NIV) has proved to be an excellent technique in selected critically ill patients with different forms of acute respiratory failure. However, NIV can fail on account of the severity of the disease and technical problems, particularly at the interface. The helmet could be an alternative interface compared to face mask to improve NIV success. We performed a clinical review to investigate the main physiological and clinical studies assessing the efficacy and related issues of NIV delivered with a helmet. A computerized search strategy of MEDLINE/PubMed (January 2000 to May 2012) and EMBASE (January 2000 to May 2012) was conducted limiting the search to retrospective, prospective, nonrandomized and randomized trials. We analyzed 152 studies from which 33 were selected, 12 physiological and 21 clinical (879 patients). The physiological studies showed that NIV with helmet could predispose to CO2 rebreathing and increase the patients' ventilator asynchrony. The main indications for NIV were acute cardiogenic pulmonary edema, hypoxemic acute respiratory failure (community-acquired pneumonia, postoperative and immunocompromised patients) and hypercapnic acute respiratory failure. In 9 of the 21 studies the helmet was compared to a face mask during either continous positive airway pressure or pressure support ventilation. In eight studies oxygenation was similar in the two groups, while the intubation rate was similar in four and lower in three studies for the helmet group compared to face mask group. The outcome was similar in six studies. The tolerance was better with the helmet in six of the studies. Although these data are limited, NIV delivered by helmet could be a safe alternative to the face mask in patients with acute respiratory failure.

2013-01-01

325

Effects of nurses' practice of a sedation protocol on sedation and consciousness levels of patients on mechanical ventilation  

PubMed Central

Background: Providing high-quality care in the intensive care units (ICUs) is a major goal of every medical system. Nurses play a crucial role in achieving this goal. One of the most important responsibilities of nurses is sedation and pain control of patients. The present study tried to assess the effect of nurses’ practice of a sedation protocol on sedation and consciousness levels and the doses of sedatives and analgesics in the ICU patients. Materials and Methods: This clinical trial was conducted on 132 ICU patients on mechanical ventilation. The patients were randomly allocated to two groups. While the control group received the ICU's routine care, the intervention group was sedated by ICU nurses based on Jacob's modified sedation protocol. The subjects’ sedation and consciousness levels were evaluated by the Richmond Agitation Sedation Scale (RASS) and the Glasgow Coma Scale (GCS), respectively. Doses of administered midazolam and morphine were also recorded. Results: The mean RASS score of the intervention group was closer to the ideal range (?1 to +1), compared to the control group (?0.95 ± 0.3 vs. ?1.88 ± 0.4). Consciousness level of the control group was lower than that of the intervention group (8.4 ± 0.4 vs. 8.8 ± 0.4). Finally, higher doses of midazolam and morphine were administered in the control group than in the intervention group. Conclusion: As nurses are in constant contact with the ICU patients, their practice of a sedation protocol can result in better sedation and pain control in the patients and reduce the administered doses of sedatives and analgesics.

Abdar, Mohammad Esmaeili; Rafiei, Hossein; Abbaszade, Abbas; Hosseinrezaei, Hakimeh; Abdar, Zahra Esmaeili; Delaram, Masoumeh; Ahmadinejad, Mehdi

2013-01-01

326

Home mechanical ventilation: outcomes according to remoteness from health center and different family education levels.  

PubMed

Throughout the world, home mechanical ventilation (HMV) is being increasingly employed to treat patients suffering from chronic respiratory failure. This present study aimed to examine the characteristics and outcomes of 27 children seen in our department over a four-year period who were treated with HMV. The causes of chronic respiratory failure were as follows: 16 (59.3%) neuromuscular disease, 6 (22.2%) primary respiratory diseases, 3 (11.1%) congenital heart disease, and 2 (7.4%) storage disease. The mean age was 59.4 months (1 day-15 years); mean follow-up for invasive ventilation was 356 (0-1200) days and for non-invasive HMV was 517 (30-1440) days. With respect to maternal educational level, 13 had graduated from elementary school and 14 from high school or university. Nine of our patients resided in Ankara, while 18 lived in rural areas of Turkey. Eleven of the 27 patients died during the HMV period (1-36 months) at home. Five patients were weaned from HMV between 1-19 months. Our experience showed that HMV can be applied successfully in chronic respiratory failure patients in Turkey. Length of the follow-up period and mortality rate were not affected by the patient's place of residence (city center or rural) or maternal level of education. PMID:20718184

Pekcan, Sevgi; Aslan, Ay?e Tana; Kiper, Nural; Köse, Mehmet; Cobanoglu, Nazan; Yalçin, Ebru; Do?ru, Deniz; Ozçelik, U?ur

2010-01-01

327

A computer expert system prototype for mechanically ventilated neonates development and impact on clinical judgment and information access capability of nurses.  

PubMed

A computer expert system is an alternative method of training and providing real-time clinical decision support for nurses to advance their practices from a novice to a proficient level. The purpose of this study was twofold: (1) to develop a prototype of a computer expert system for mechanically ventilated neonates (ES-MVN) and (2) to assess the impact of the ES-MVN on the clinical judgment and information access capability of nurses. Five steps used in developing the prototype are described in this article. The ES-MVN is a multimedia interactive consultation-based program that contains 2 major parts: the nursing diagnosis and the knowledge base on nursing care of mechanically ventilated neonates. A rule-based (Boolean frame) was chosen for the nursing diagnosis decision model. The prototype was developed on the Web server and a combination of computer applications operated in a Microsoft Windows environment. A quasi-experimental, 1-group pretest-posttest design was used to measure the efficacy of the ES-MVN in 16 neonatal intensive care unit registered nurses. Case simulations were used to test the nurses' clinical judgment performance. The results showed a significant increase in the nurses' performance scores of diagnoses and managed care after using the ES-MVN (t[15] = 17.21, P = .0001). The nurses' scores for perceptions of their information access capability and clinical judgment ability after receiving the ES-MVN were significantly higher than before installing the ES-MVN in the neonatal intensive care unit (ts[15] = 6.91 and = 17.53, Ps = .0001, respectively). The findings suggest the usefulness of the computer expert system as an effective tool to support nurses' clinical judgment in critical care situations and to provide access to information at the practice site. PMID:11577661

Jirapaet, V

2001-01-01

328

Successful Treatment of a Neonate with Idiopathic Persistent Pulmonary Hypertension with Inhaled Nitric Oxide via Nasal Cannula without Mechanical Ventilation  

PubMed Central

We report a case study of a term neonate presenting with oxygen desaturation without respiratory distress or acidosis, despite receiving 100% oxygen through a nasal cannula. Echocardiogram showed evidence of persistent pulmonary hypertension of the newborn (PPHN). She was successfully treated with inhaled nitric oxide (iNO) via nasal cannula without requiring mechanical ventilation. In a term neonate with idiopathic PPHN with adequate respiratory drive without any parenchymal lung disease, noninvasive methods of iNO delivery may treat the condition without the complications associated with mechanical ventilation.

Nair, Jayasree; Orie, Joseph; Lakshminrusimha, Satyan

2012-01-01

329

Effects of Different Peep Levels on Mesenteric Leukocyte-Endothelial Interactions in Rats During Mechanical Ventilation  

PubMed Central

INTRODUCTION: Mechanical ventilation with positive end expiratory pressure (PEEP) improves oxygenation and treats acute pulmonary failure. However, increased intrathoracic pressure may cause regional blood flow alterations that may contribute to mesenteric ischemia and gastrointestinal failure. We investigated the effects of different PEEP levels on mesenteric leukocyte-endothelial interactions. METHODS: Forty-four male Wistar rats were initially anesthetized (Pentobarbital I.P. 50mg/kg) and randomly assigned to one of the following groups: 1) NAIVE (only anesthesia; n=9), 2) PEEP 0 (PEEP of 0 cmH2O, n=13), 3) PEEP 5 (PEEP of 5 cmH2O, n=12), and 4) PEEP 10 (PEEP of 10 cmH2O, n=13). Positive end expiratory pressure groups were tracheostomized and mechanically ventilated with a tidal volume of 10 mL/kg, respiratory rate of 70 rpm, and inspired oxygen fraction of 1. Animals were maintained under isoflurane anesthesia. After two hours, laparotomy was performed, and leukocyte-endothelial interactions were evaluated by intravital microscopy. RESULTS: No significant changes were observed in mean arterial blood pressure among groups during the study. Tracheal peak pressure was smaller in PEEP 5 compared with PEEP 0 and PEEP 10 groups (11, 15, and 16 cmH2O, respectively; p<0.05). After two hours of MV, there were no differences among NAIVE, PEEP 0 and PEEP 5 groups in the number of rollers (118±9,127±14 and 147±26 cells/10minutes, respectively), adherent leukocytes (3±1,3±1 and 4±2 cells/100?m venule length, respectively), and migrated leukocytes (2±1,2±1 and 2±1 cells/5,000?m2, respectively) at the mesentery. However, the PEEP 10 group exhibited an increase in the number of rolling, adherent and migrated leukocytes (188±15 cells / 10 min, 8±1 cells / 100 ?m and 12±1 cells / 5,000 ?m2, respectively; p<0.05). CONCLUSIONS: High intrathoracic pressure was harmful to mesenteric microcirculation in the experimental model of rats with normal lungs and stable systemic blood pressure, a finding that may have relevance for complications related to mechanical ventilation.

Aikawa, Priscila; Farsky, Sandra Helena Poliselli; de Oliveira, Maria Aparecida; Pazetti, Rogerio; Mauad, Thais; Sannomiya, Paulina; Nakagawa, Naomi Kondo

2009-01-01

330

[Responding to patients with home mechanical ventilation after the Great East Japan Earthquake and during the planned power outages. How should we be prepared for a future disaster ?].  

PubMed

The unprecedented earthquake(magnitude-9 in the Japanese seismic intensity scale)hit off the east coast of Japan on March 11, 2011. Consequently, there were planned power outages in the area nearby Tokyo to avoid massive blackouts caused by a stoppage of Fukushima nuclear plants.Our clinic located in Kawasaki city was also hit by the earthquake(magnitude- 5).During the period of two months(March and April 2011), we had a total of 52 patients with home respiratory care (5-TPPV, 11-NPPV and 36-HOT)at that time.Two out of three 24 hour-TPPV users had no external battery.After the earthquake, there was a 7-hour electricity failure in some areas, and a patient with ASV(adaptive servo ventilator)was living there.Moreover, 3-hour/day power outages were carried out from March 14 to March 28, affecting people's everyday lives. However, the patient had no harmful influences from the power failure because a ventilation company lent us an external battery(4-9 hour life capacity)for the patients, and we were able to avoid an emergency situation caused by the power failure.In conclusion, we ought to be prepared for patients with home mechanical ventilation in the future toward unforeseen large scale power outages. PMID:22189317

Takechi, Yukako

2011-12-01

331

Online learning versus simulation for teaching principles of mechanical ventilation to nurse practitioner students.  

PubMed

Patient simulation is increasingly used in the education of healthcare providers, yet few studies have compared simulation to other teaching modalities. The purpose of this study was to determine differences in knowledge acquisition and student satisfaction between two methods of teaching the principles of mechanical ventilation to advanced practice nursing (APN) students: high-fidelity patient simulation (including face-to-face instruction) versus an online, narrated PowerPoint presentation. Twenty APN students were randomized to either the simulation or online teaching method in this pre/posttest study. Measures included a 12-item knowledge questionnaire and a 5-item satisfaction survey. Both groups had significant improvement in knowledge scores from pretest to posttest, but knowledge scores were not significantly different at posttest between groups. Student satisfaction with their learning method was significantly higher in the simulation group. Students choosing to participate in the alternative teaching method after study completion preferred the simulation to the online method. PMID:20361860

Corbridge, Susan J; Robinson, F Patrick; Tiffen, Jennifer; Corbridge, Thomas C

2010-01-01

332

Determination of respiratory gas flow by electrical impedance tomography in an animal model of mechanical ventilation  

PubMed Central

Background A recent method determines regional gas flow of the lung by electrical impedance tomography (EIT). The aim of this study is to show the applicability of this method in a porcine model of mechanical ventilation in healthy and diseased lungs. Our primary hypothesis is that global gas flow measured by EIT can be correlated with spirometry. Our secondary hypothesis is that regional analysis of respiratory gas flow delivers physiologically meaningful results. Methods In two sets of experiments n?=?7 healthy pigs and n?=?6 pigs before and after induction of lavage lung injury were investigated. EIT of the lung and spirometry were registered synchronously during ongoing mechanical ventilation. In-vivo aeration of the lung was analysed in four regions-of-interest (ROI) by EIT: 1) global, 2) ventral (non-dependent), 3) middle and 4) dorsal (dependent) ROI. Respiratory gas flow was calculated by the first derivative of the regional aeration curve. Four phases of the respiratory cycle were discriminated. They delivered peak and late inspiratory and expiratory gas flow (PIF, LIF, PEF, LEF) characterizing early or late inspiration or expiration. Results Linear regression analysis of EIT and spirometry in healthy pigs revealed a very good correlation measuring peak flow and a good correlation detecting late flow. PIFEIT?=?0.702?·?PIFspiro?+?117.4, r2?=?0.809; PEFEIT?=?0.690?·?PEFspiro-124.2, r2?=?0.760; LIFEIT?=?0.909?·?LIFspiro?+?27.32, r2?=?0.572 and LEFEIT?=?0.858?·?LEFspiro-10.94, r2?=?0.647. EIT derived absolute gas flow was generally smaller than data from spirometry. Regional gas flow was distributed heterogeneously during different phases of the respiratory cycle. But, the regional distribution of gas flow stayed stable during different ventilator settings. Moderate lung injury changed the regional pattern of gas flow. Conclusions We conclude that the presented method is able to determine global respiratory gas flow of the lung in different phases of the respiratory cycle. Additionally, it delivers meaningful insight into regional pulmonary characteristics, i.e. the regional ability of the lung to take up and to release air.

2014-01-01

333

A mobile care system with alert mechanism.  

PubMed

Hypertension and arrhythmia are chronic diseases, which can be effectively prevented and controlled only if the physiological parameters of the patient are constantly monitored, along with the full support of the health education and professional medical care. In this paper, a role-based intelligent mobile care system with alert mechanism in chronic care environment is proposed and implemented. The roles in our system include patients, physicians, nurses, and healthcare providers. Each of the roles represents a person that uses a mobile device such as a mobile phone to communicate with the server setup in the care center such that he or she can go around without restrictions. For commercial mobile phones with Bluetooth communication capability attached to chronic patients, we have developed physiological signal recognition algorithms that were implemented and built-in in the mobile phone without affecting its original communication functions. It is thus possible to integrate several front-end mobile care devices with Bluetooth communication capability to extract patients' various physiological parameters [such as blood pressure, pulse, saturation of haemoglobin (SpO2), and electrocardiogram (ECG)], to monitor multiple physiological signals without space limit, and to upload important or abnormal physiological information to healthcare center for storage and analysis or transmit the information to physicians and healthcare providers for further processing. Thus, the physiological signal extraction devices only have to deal with signal extraction and wireless transmission. Since they do not have to do signal processing, their form factor can be further reduced to reach the goal of microminiaturization and power saving. An alert management mechanism has been included in back-end healthcare center to initiate various strategies for automatic emergency alerts after receiving emergency messages or after automatically recognizing emergency messages. Within the time intervals in system setting, according to the medical history of a specific patient, our prototype system can inform various healthcare providers in sequence to provide healthcare service with their reply to ensure the accuracy of alert information and the completeness of early warning notification to further improve the healthcare quality. In the end, with the testing results and performance evaluation of our implemented system prototype, we conclude that it is possible to set up a complete intelligent healt care chain with mobile monitoring and healthcare service via the assistance of our system. PMID:17912967

Lee, Ren-Guey; Chen, Kuei-Chien; Hsiao, Chun-Chieh; Tseng, Chwan-Lu

2007-09-01

334

Ventilation and ventilators.  

PubMed

The history of ventilation is reviewed briefly and recent developments in techniques of ventilation are discussed. Operating features of ventilators have changed in the past few years, partly as the result of clinical progress; yet, technology appears to have outstripped the clinician's ability to harness it most effectively. Clinical discipline and training of medical staff in the use of ventilators could be improved. The future is promising if clinician and designer can work together closely. Ergonomics of ventilators and their controls and the provision of alarms need special attention. Microprocessors are likely to feature prominently in the next generation of designs. PMID:6754938

Hayes, B

1982-01-01

335

The application of mechanical aerosol delivery systems in an in vitro model of mechanically ventilated neonates.  

PubMed

Delivery of medication to the neonatal lung using current methods is inefficient. Aerosols offer one way to improve delivery to small airways. In this in vitro work, aerosol delivery by using a micropump or a rotary valve has been evaluated in a model of the neonatal setting with a pressurised metered dose inhaler plus spacer outside of the inspiratory limb. Drug depositions were assessed by spectrophotometric analyses. Drug lung deposition was increased by adjusting the rotary valve for co-ordination between the inhalation and aerosol delivery, but this intermittent mode decreased the aerosol delivery by using the micropump. Also, decreasing the volume of spacer decreased drug deposition in test lungs by using the micropump system. At the optimum conditions, the rotary valve aerosol delivery system delivered 3.68±0.91% of the Qvar nominal dose to the test lungs, and this was 2.34±0.01% for the micropump system. In conclusion, the rotary valve aerosol delivery system provided higher amounts of drug particles to the test lungs compared to the micropump system. The advantages of these methods were that the humidity in the ventilation circuit did not affect the aerosol particles in the spacer. Further optimisation is required to improve aerosol deposition in the test lungs. The article has also a short section of recent patents relevant to aerosol delivery. PMID:24021087

Ehtezazi, Touraj; Turner, Mark A

2013-12-01

336

A model-based simulator for testing rule-based decision support systems for mechanical ventilation of ARDS patients.  

PubMed

A model-based simulator was developed for testing rule-based decision support systems that manages ventilator therapy of patients with the Adult Respiratory Distress Syndrome (ARDS). The simulator is based on a multi-compartment model of the human body and mathematical models of the gas exchange abnormalities associated with ARDS. Initial testing of this system indicates that model-based simulators are a viable tool for testing rule-based expert systems used in health-care. PMID:7949849

Sailors, R M; East, T D

1994-01-01

337

Replacement of fentanyl infusion by enteral methadone decreases the weaning time from mechanical ventilation: a randomized controlled trial  

PubMed Central

Introduction Patients undergoing mechanical ventilation (MV) are frequently administered prolonged and/or high doses of opioids which when removed can cause a withdrawal syndrome and difficulty in weaning from MV. We tested the hypothesis that the introduction of enteral methadone during weaning from sedation and analgesia in critically ill adult patients on MV would decrease the weaning time from MV. Methods A double-blind randomized controlled trial was conducted in the adult intensive care units (ICUs) of four general hospitals in Brazil. The 75 patients, who met the criteria for weaning from MV and had been using fentanyl for more than five consecutive days, were randomized to the methadone (MG) or control group (CG). Within the first 24 hours after study enrollment, both groups received 80% of the original dose of fentanyl, the MG received enteral methadone and the CG received an enteral placebo. After the first 24 hours, the MG received an intravenous (IV) saline solution (placebo), while the CG received IV fentanyl. For both groups, the IV solution was reduced by 20% every 24 hours. The groups were compared by evaluating the MV weaning time and the duration of MV, as well as the ICU stay and the hospital stay. Results Of the 75 patients randomized, seven were excluded and 68 were analyzed: 37 from the MG and 31 from the CG. There was a higher probability of early extubation in the MG, but the difference was not significant (hazard ratio: 1.52 (95% confidence interval (CI) 0.87 to 2.64; P = 0.11). The probability of successful weaning by the fifth day was significantly higher in the MG (hazard ratio: 2.64 (95% CI: 1.22 to 5.69; P < 0.02). Among the 54 patients who were successfully weaned (29 from the MG and 25 from the CG), the MV weaning time was significantly lower in the MG (hazard ratio: 2.06; 95% CI 1.17 to 3.63; P < 0.004). Conclusions The introduction of enteral methadone during weaning from sedation and analgesia in mechanically ventilated patients resulted in a decrease in the weaning time from MV.

2012-01-01

338

Prevalence and impact of alcohol and other drug use disorders on sedation and mechanical ventilation: a retrospective study  

PubMed Central

Background Experience suggests that patients with alcohol and other drug use disorders (AOD) are commonly cared for in our intensive care units (ICU's) and require more sedation. We sought to determine the impact of AOD on sedation requirement and mechanical ventilation (MV) duration. Methods Retrospective review of randomly selected records of adult patients undergoing MV in the medical ICU. Diagnoses of AOD were identified using strict criteria in Diagnostic and Statistical Manual of Mental Disorders, and through review of medical records and toxicology results. Results Of the 70 MV patients reviewed, 27 had AOD (39%). Implicated substances were alcohol in 22 patients, cocaine in 5, heroin in 2, opioids in 2, marijuana in 2. There was no difference between AOD and non-AOD patients in age, race, or reason for MV, but patients with AOD were more likely to be male (21 versus 15, p < 0.0001) and had a lower mean Acute Physiology and Chronic Health Evaluation II (22 versus 26, p = 0.048). While AOD patients received more lorazepam equivalents (0.5 versus 0.2 mg/kg.day, p = 0.004), morphine equivalents (0.5 versus 0.1 mg/kg.day, p = 0.03) and longer duration of infusions (16 versus 10 hours/day. medication, p = 0.002), they had similar sedation levels (Richmond Agitation-Sedation Scale (RASS) -2 versus -2, p = 0.83), incidence of agitation (RASS ? 3: 3.0% versus 2.4% of observations, p = 0.33), and duration of MV (3.6 versus 3.9 days, p = 0.89) as those without AOD. Conclusion The prevalence of AOD among medical ICU patients undergoing MV is high. Patients with AOD receive higher doses of sedation than their non-AOD counterparts to achieve similar RASS scores but do not undergo longer duration of MV.

de Wit, Marjolein; Wan, Sau Yin; Gill, Sujoy; Jenvey, Wendy I; Best, Al M; Tomlinson, Judith; Weaver, Michael F

2007-01-01

339

Hyperventilation versus standard ventilation for infants in postoperative care for congenital heart defects with pulmonary hypertension  

Microsoft Academic Search

Purpose  In infants undergoing surgery for cardiac defects with left-to-right shunt, a hyperventilation strategy has been applied to\\u000a prevent pulmonary hypertensive crisis (PHC). Hyperventilation with a large tidal volume and\\/or higher airway pressure, however,\\u000a may be detrimental to the lung. This randomized study compared the effects of hyperventilation versus standard ventilation.\\u000a \\u000a \\u000a \\u000a Methods  We enrolled 22 infants with a preoperative pulmonary-to-systemic blood pressure

Takako Umenai; Nobuaki Shime; Satoru Hashimoto

2009-01-01

340

Expiratory Washout versus Optimization of Mechanical Ventilation during Permissive Hypercapnia in Patients with Severe Acute Respiratory Distress Syndrome  

Microsoft Academic Search

The aim of this study was to compare three ventilatory techniques for reducing Pa CO 2 in patients with severe acute respiratory distress syndrome treated with permissive hypercapnia: ( 1 ) expiratory wash- out alone at a flow of 15 L\\/min, ( 2 ) optimized mechanical ventilation defined as an increase in the respiratory frequency to the maximal rate possible

JACK RICHECOEUR; QIN LU; SILVIA R. R. VIEIRA; LOUIS PUYBASSET; PIERRE CORIAT; JEAN-JACQUES ROUBY

341

Outcome of direct percutaneous endoscopic jejunostomy tube placement for nutritional support in critically ill, mechanically ventilated patients  

Microsoft Academic Search

Purpose: Gastrointestinal function is adversely affected in critically ill mechanically ventilated patients. The most common abnormality is delayed gastric emptying. Among the options for postpyloric feeds, direct percutaneous endoscopic jejunostomy (PEJ) provides a permanent, reliable, and direct access to the small bowel and can be used for full enteral feedings, thus eliminating the need for parenteral nutrition. Patients and Methods:

Rafael Barrera; Mark Schattner; Stephen Nygard; Michael Ahdoot; Allan Ahdoot; Samuel Adeyeye; Jeffrey Groeger; Moshe Shike

2001-01-01

342

Mechanical Ventilation and Acute Lung Injury in Emergency Department Patients with Severe Sepsis and Septic Shock: an Observational Study  

PubMed Central

Objectives To characterize the use of mechanical ventilation in the emergency department (ED), with respect to ventilator settings, monitoring, and titration; and to determine the incidence of progression to acute lung injury (ALI) after admission, examining the influence of factors present in the ED on ALI progression. Methods This was a retrospective, observational cohort study of mechanically ventilated patients with severe sepsis and septic shock (June 2005 to May 2010), presenting to an academic ED with an annual census of >95,000 patients. All patients in the study (n = 251) were analyzed for characterization of mechanical ventilation use in the ED. The primary outcome variable of interest was the incidence of ALI progression after ICU admission from the ED and risk factors present in the ED associated with this outcome. Secondary analyses included ALI present in the ED and clinical outcomes comparing all patients progressing to ALI versus no ALI. To assess predictors of progression to ALI, statistically significant variables in univariable analyses at a p ? 0.10 level were candidates for inclusion in a bidirectional, stepwise, multivariable logistic regression analysis. Results Lung-protective ventilation was used in 68 patients (27.1%), and did not differ based on ALI status. Delivered tidal volume was highly variable, with a median tidal volume delivered of 8.8 mL/kg ideal body weight (IBW) (IQR 7.8 to 10.0), and a range of 5.2 to 14.6 mL/kg IBW. Sixty-nine patients (27.5%) in the entire cohort progressed to ALI after admission to the hospital, with a mean onset of 2.1 days (SD ± 1 day). Multivariable logistic regression analysis demonstrated that a higher body mass index, higher Sequential Organ Failure Assessment score, and ED vasopressor use were associated with progression to ALI. There was no association between ED ventilator settings and progression to ALI. Compared to patients who did not progress to ALI, patients progressing to ALI after admission from the ED had an increase in mechanical ventilator duration, vasopressor dependence, and hospital length of stay. Conclusions Lung-protective ventilation is uncommon in the ED, regardless of ALI status. Given the frequency of ALI in the ED, the progression shortly after ICU admission, and the clinical consequences of this syndrome, the effect of ED-based interventions aimed at reducing the sequelae of ALI should be investigated further.

Fuller, Brian M.; Mohr, Nicholas M.; Dettmer, Matthew; Kennedy, Sarah; Cullison, Kevin; Bavolek, Rebecca; Rathert, Nicholas; McCammon, Craig

2013-01-01

343

Application of heart-rate variability in patients undergoing weaning from mechanical ventilation  

PubMed Central

Introduction The process of weaning may impose cardiopulmonary stress on ventilated patients. Heart-rate variability (HRV), a noninvasive tool to characterize autonomic function and cardiorespiratory interaction, may be a promising modality to assess patient capability during the weaning process. We aimed to evaluate the association between HRV change and weaning outcomes in critically ill patients. Methods This study included 101 consecutive patients recovering from acute respiratory failure. Frequency-domain analysis, including very low frequency, low frequency, high frequency, and total power of HRV was assessed during a 1-hour spontaneous breathing trial (SBT) through a T-piece and after extubation after successful SBT. Results Of 101 patients, 24 (24%) had SBT failure, and HRV analysis in these patients showed a significant decrease in total power (P = 0.003); 77 patients passed SBT and were extubated, but 13 (17%) of them required reintubation within 72 hours. In successfully extubated patients, very low frequency and total power from SBT to postextubation significantly increased (P = 0.003 and P = 0.004, respectively). Instead, patients with extubation failure were unable to increase HRV after extubation. Conclusions HRV responses differ between patients with different weaning outcomes. Measuring HRV change during the weaning process may help clinicians to predict weaning results and, in the end, to improve patient care and outcome.

2014-01-01

344

Mechanical ventilation-induced apoptosis in newborn rat lung is mediated via FasL/Fas pathway.  

PubMed

Mechanical ventilation induces pulmonary apoptosis and inhibits alveolar development in preterm infants, but the molecular basis for the apoptotic injury is unknown. The objective was to determine the signaling mechanism(s) of ventilation (stretch)-induced apoptosis in newborn rat lung. Seven-day-old rats were ventilated with room air for 24 h using moderate tidal volumes (8.5 ml/kg). Isolated fetal rat lung epithelial and fibroblast cells were subjected to continuous cyclic stretch (5, 10, or 17% elongation) for up to 12 h. Prolonged ventilation significantly increased the number of apoptotic alveolar type II cells (i.e., terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling and anti-cleaved caspase-3 immunochemistry) and was associated with increased expression of the apoptotic mediator Fas ligand (FasL). Fetal lung epithelial cells, but not fibroblasts, subjected to maximal (i.e., 17%, but not lesser elongation) cyclic stretch exhibited increased apoptosis (i.e., nuclear fragmentation and DNA laddering), which appeared to be mediated via the extrinsic pathway (increased expression of FasL and cleaved caspase-3, -7, and -8). The intrinsic pathway appeared not to be involved [minimal mitochondrial membrane depolarization (JC-1 flow analysis) and no activation of caspase-9]. Universal caspases inhibition and neutralization of FasL abrogated the stretch-induced apoptosis. Prolonged mechanical ventilation induces apoptosis of alveolar type II cells in newborn rats and the mechanism appears to involve activation of the extrinsic death pathway via the FasL/Fas system. PMID:23934924

Kroon, Andreas A; Delriccio, Veronica; Tseu, Irene; Kavanagh, Brian P; Post, Martin

2013-12-01

345

Effect of a scoring system and protocol for sedation on duration of patients’ need for ventilator support in a surgical intensive care unit  

Microsoft Academic Search

Problem: Need for improved sedation strategy for adults receiving ventilator support.Design: Observational study of effect of introduction of guidelines to improve the doctors’ and nurses’ performance. The project was a prospective improvement and was part of a national quality improvement collaborative.Background and setting: A general mixed surgical intensive care unit in a university hospital; all doctors and nurses in the

G Brattebø; D Hofoss; H Flaatten; A K Muri; S Gjerde; P E Plsek

2004-01-01

346

A study on circadian rhythm disorder of rat lung tissue caused by mechanical ventilation induced lung injury.  

PubMed

Ventilator-induced lung injury (VILI), the most serious complication of mechanical ventilation therapy, is an excessive inflammatory response in lung tissue characterized by infiltration of inflammatory cells and overproduction of inflammatory mediators. The pathogenesis of VILI is very complex. It is becoming increasingly evident that disruption of circadian rhythm affects the immune response. Whether the pathogenesis of VILI is associated with circadian rhythm disruption has not been reported. In this study, we establish VILI model in SD rat by performing an endotracheal intubation and placing the rat on a mechanical ventilator (tidal volume of 40 ml/kg or 10 ml/kg without positive end-expiratory pressure). To examine the effect of VILI on clock gene expression, real-time quantitative PCR was performed to measure bmal1, clock, per2 and Rev-erb? mRNA expression. We found that Rev-erb? mRNA was significantly decreased in high tide volume mechanical ventilation group compared with spontaneous group, the same as REV-ERB? protein product which was tested by Western blot approach. Stimulation of REV-ERB? activity by SR9009 greatly diminished VILI-induced lung edema, inflammatory cell infiltration and the production of the pro-inflammatory cytokine TNF-?. Collectively, our findings are the first to show that REV-ERB? plays an important role in VILI and inflammation, and circadian rhythm disorder in inflammation response may be a novel pathogenesis of VILI. PMID:24355794

Li, Huan; Wang, Chunxiao; Hu, Jiaqi; Tan, Junyuan

2014-02-01

347

Intrathoracic blood volume accurately reflects circulatory volume status in critically ill patients with mechanical ventilation  

Microsoft Academic Search

Positive pressure ventilation in patients with acute respiratory failure (ARF) may render the interpretation of central venous pressure (CVP) or pulmonary wedge pressure (PCWP) difficult as indicators of circulating volume. The preload component of cardiac (CI) and stroke index (SI) is also influenced by the increased intrathoracic pressures of positive pressure ventilation. Moreover CI and SI do not indicate volume

M. Lichtwarck-Aschoff; J. Zeravik; U. J. Pfeiffer

1992-01-01

348

Mechanical or Partly Natural Ventilation in Pigsties. Climate and Energy Consumption.  

National Technical Information Service (NTIS)

When automatic control is utilized in connection with ventilation systems used in pigsties, the motors activating the system are only started up when the ventholes in the walls are fully opened. In this way the installation functions as a ''natural ventil...

F. Moeller

1989-01-01

349

The effect of positive-end expiratory pressure on oxygenation during high frequency jet ventilation and conventional mechanical ventilation in the rabbit model of acute lung injury  

PubMed Central

Background The use of positive end expiratory pressure (PEEP) in patients with acute lung injury (ALI) improves arterial oxygenation by alleviating pulmonary shunting, helping the respiratory muscles to decrease the work of breathing, decreasing the rate of infiltrated and atelectatic tissues, and increasing functional residual capacity. In a rabbit model of saline lavage-induced ALI, we examined the effects of PEEP on gas exchange, hemodynamics, and oxygenation during high frequency jet ventilation (HFJV), and then compared these parameters with those during conventional mechanical ventilation (CMV). Methods Twelve rabbits underwent repeated saline lavage to create ALI. The animals were divided in 2 groups: 1) Group CMV (n = 6), and 2) Group HFJV (n = 6). In both groups, we applied 2 levels of PEEP (5 cmH2O and 10 cmH2O) and then measured the arterial blood gas, mixed venous blood gas, and hemodynamic parameters. Results With administration of PEEP of either 5 cmH2O or 10 cmH2O, the arterial oxygen content of both groups was increased, although without statistically significant differences between groups. On the contrary, the arterial carbon dioxide content was significantly decreased in the HFJV group, as compared with the CMV group, during the entire experiment. Furthermore, there was significant decreases in mean arterial pressures in both groups with a PEEP of 10 cmH2O. Conclusions The application of PEEP in rabbits with ALI effectively improves oxygenation in either HFJV or CMV.

Bang, Jae Ouk; Ha, Seung Il

2012-01-01

350

Intelligent model-based advisory system for the management of ventilated intensive care patients. Part II: Advisory system design and evaluation.  

PubMed

The optimisation of ventilatory support is a crucial issue for the management of respiratory failure in critically ill patients, aiming at improving gas exchange while preventing ventilator-induced dysfunction of the respiratory system. Clinicians often rely on their knowledge/experience and regular observation of the patient's response for adjusting the level of respiratory support. Using a similar data-driven decision-making methodology, an adaptive model-based advisory system has been designed for the clinical monitoring and management of mechanically ventilated patients. The hybrid blood gas patient model SOPAVent developed in Part I of this paper and validated against clinical data for a range of patients lung abnormalities is embedded into the advisory system to predict continuously and non-invasively the patient's respiratory response to changes in the ventilator settings. The choice of appropriate ventilator settings involves finding a balance among a selection of fundamentally competing therapeutic decisions. The design approach used here is based on a goal-directed multi-objective optimisation strategy to determine the optimal ventilator settings that effectively restore gas exchange and promote improved patient's clinical conditions. As an initial step to its clinical validation, the advisory system's closed-loop stability and performance have been assessed in a series of simulations scenarios reconstructed from real ICU patients data. The results show that the designed advisory system can generate good ventilator-setting advice under patient state changes and competing ventilator management targets. PMID:20398957

Wang, Ang; Mahfouf, Mahdi; Mills, Gary H; Panoutsos, G; Linkens, D A; Goode, K; Kwok, Hoi-Fei; Denaï, Mouloud

2010-08-01

351

An air flow sensor for neonatal mechanical ventilation applications based on a novel fiber-optic sensing technique  

SciTech Connect

In this work, a simple and low-cost air flow sensor, based on a novel fiber-optic sensing technique has been developed for monitoring air flows rates supplied by a neonatal ventilator to support infants in intensive care units. The device is based on a fiber optic sensing technique allowing (a) the immunity to light intensity variations independent by measurand and (b) the reduction of typical shortcomings affecting all biomedical fields (electromagnetic interference and patient electrical safety). The sensing principle is based on the measurement of transversal displacement of an emitting fiber-optic cantilever due to action of air flow acting on it; the fiber tip displacement is measured by means of a photodiode linear array, placed in front of the entrance face of the emitting optical fiber in order to detect its light intensity profile. As the measurement system is based on a detection of the illumination pattern, and not on an intensity modulation technique, it results less sensitive to light intensity fluctuation independent by measurand than intensity-based sensors. The considered technique is here adopted in order to develop two different configurations for an air flow sensor suitable for the measurement of air flow rates typically occurring during mechanical ventilation of newborns: a mono-directional and a bi-directional transducer have been proposed. A mathematical model for the air flow sensor is here proposed and a static calibration of two different arrangements has been performed: a measurement range up to 3.00 Multiplication-Sign 10{sup -4} m{sup 3}/s (18.0 l/min) for the mono-directional sensor and a measurement range of {+-}3.00 Multiplication-Sign 10{sup -4} m{sup 3}/s ({+-}18.0 l/min) for the bi-directional sensor are experimentally evaluated, according to the air flow rates normally encountered during tidal breathing of infants with a mass lower than 10 kg. Experimental data of static calibration result in accordance with the proposed theoretical model: for the mono-directional configuration, the coefficient of determination r{sup 2} is equal to 0.997; for the bi-directional configuration, the coefficient of determination r{sup 2} is equal to 0.990 for positive flows (inspiration) and 0.988 for negative flows (expiration). Measurement uncertainty {delta}Q of air flow rate has been evaluated by means of the propagation of distributions and the percentage error in the arrangement of bi-directional sensor ranges from a minimum of about 0.5% at -18.0 l/min to a maximum of about 9% at -12.0 l/min.

Battista, L.; Sciuto, S. A.; Scorza, A. [Department of Engineering, ROMA TRE University, via della Vasca Navale 79/81, Rome (Italy)

2013-03-15

352

An air flow sensor for neonatal mechanical ventilation applications based on a novel fiber-optic sensing technique.  

PubMed

In this work, a simple and low-cost air flow sensor, based on a novel fiber-optic sensing technique has been developed for monitoring air flows rates supplied by a neonatal ventilator to support infants in intensive care units. The device is based on a fiber optic sensing technique allowing (a) the immunity to light intensity variations independent by measurand and (b) the reduction of typical shortcomings affecting all biomedical fields (electromagnetic interference and patient electrical safety). The sensing principle is based on the measurement of transversal displacement of an emitting fiber-optic cantilever due to action of air flow acting on it; the fiber tip displacement is measured by means of a photodiode linear array, placed in front of the entrance face of the emitting optical fiber in order to detect its light intensity profile. As the measurement system is based on a detection of the illumination pattern, and not on an intensity modulation technique, it results less sensitive to light intensity fluctuation independent by measurand than intensity-based sensors. The considered technique is here adopted in order to develop two different configurations for an air flow sensor suitable for the measurement of air flow rates typically occurring during mechanical ventilation of newborns: a mono-directional and a bi-directional transducer have been proposed. A mathematical model for the air flow sensor is here proposed and a static calibration of two different arrangements has been performed: a measurement range up to 3.00 × 10(-4) m(3)?s (18.0 l?min) for the mono-directional sensor and a measurement range of ±3.00 × 10(-4) m(3)?s (±18.0 l?min) for the bi-directional sensor are experimentally evaluated, according to the air flow rates normally encountered during tidal breathing of infants with a mass lower than 10 kg. Experimental data of static calibration result in accordance with the proposed theoretical model: for the mono-directional configuration, the coefficient of determination r(2) is equal to 0.997; for the bi-directional configuration, the coefficient of determination r(2) is equal to 0.990 for positive flows (inspiration) and 0.988 for negative flows (expiration). Measurement uncertainty ?Q of air flow rate has been evaluated by means of the propagation of distributions and the percentage error in the arrangement of bi-directional sensor ranges from a minimum of about 0.5% at -18.0 l?min to a maximum of about 9% at -12.0 l?min. PMID:23556844

Battista, L; Sciuto, S A; Scorza, A

2013-03-01

353

An air flow sensor for neonatal mechanical ventilation applications based on a novel fiber-optic sensing technique  

NASA Astrophysics Data System (ADS)

In this work, a simple and low-cost air flow sensor, based on a novel fiber-optic sensing technique has been developed for monitoring air flows rates supplied by a neonatal ventilator to support infants in intensive care units. The device is based on a fiber optic sensing technique allowing (a) the immunity to light intensity variations independent by measurand and (b) the reduction of typical shortcomings affecting all biomedical fields (electromagnetic interference and patient electrical safety). The sensing principle is based on the measurement of transversal displacement of an emitting fiber-optic cantilever due to action of air flow acting on it; the fiber tip displacement is measured by means of a photodiode linear array, placed in front of the entrance face of the emitting optical fiber in order to detect its light intensity profile. As the measurement system is based on a detection of the illumination pattern, and not on an intensity modulation technique, it results less sensitive to light intensity fluctuation independent by measurand than intensity-based sensors. The considered technique is here adopted in order to develop two different configurations for an air flow sensor suitable for the measurement of air flow rates typically occurring during mechanical ventilation of newborns: a mono-directional and a bi-directional transducer have been proposed. A mathematical model for the air flow sensor is here proposed and a static calibration of two different arrangements has been performed: a measurement range up to 3.00 × 10-4 m3/s (18.0 l/min) for the mono-directional sensor and a measurement range of +/-3.00 × 10-4 m3/s (+/-18.0 l/min) for the bi-directional sensor are experimentally evaluated, according to the air flow rates normally encountered during tidal breathing of infants with a mass lower than 10 kg. Experimental data of static calibration result in accordance with the proposed theoretical model: for the mono-directional configuration, the coefficient of determination r2 is equal to 0.997; for the bi-directional configuration, the coefficient of determination r2 is equal to 0.990 for positive flows (inspiration) and 0.988 for negative flows (expiration). Measurement uncertainty ?Q of air flow rate has been evaluated by means of the propagation of distributions and the percentage error in the arrangement of bi-directional sensor ranges from a minimum of about 0.5% at -18.0 l/min to a maximum of about 9% at -12.0 l/min.

Battista, L.; Sciuto, S. A.; Scorza, A.

2013-03-01

354

Association between mechanical ventilation and neurodevelopmental disorders in a nationwide cohort of extremely low birth weight infants.  

PubMed

Mechanical ventilation for preterm infants independently contributes to poor neurodevelopmental performance. However, few studies have investigated the association between the duration of mechanical ventilation and the risk for various developmental disorders in extremely low birth weight (ELBW) (<1000g) infants. Using a large nationwide database, we did a 10-year retrospective follow-up study to explore the effect of mechanical ventilation on the incidence of cerebral palsy (CP), autism spectrum disorder (ASD), intellectual disability (ID), and attention-deficit/hyperactivity disorder (ADHD) in ELBW infants born between 1998 and 2001. Seven hundred twenty-eight ELBW infants without diagnoses of brain insults or focal brain lesions in the initial hospital stay were identified and divided into three groups (days on ventilator: ?2, 3-14, ?15 days). After adjusting for demographic and medical factors, the infants in the ?15 days group had higher risks for CP (adjusted hazard ratio: 2.66; 95% confidence interval: 1.50-4.59; p<0.001) and ADHD (adjusted hazard ratio: 1.95; 95% confidence interval: 1.02-3.76; p<0.05), than did infants in the ?2 days group. The risk for ASD or ID was not significantly different between the three groups. We conclude that mechanical ventilation for ?15 days increased the risk for CP and ADHD in ELBW infants even without significant neonatal brain damage. Developing a brain-protective respiratory support strategy in response to real-time cerebral hemodynamic and oxygenation changes has the potential to improve neurodevelopmental outcomes in ELBW infants. PMID:24769371

Tsai, Wen-Hui; Hwang, Yea-Shwu; Hung, Te-Yu; Weng, Shih-Feng; Lin, Shio-Jean; Chang, Wen-Tsan

2014-07-01

355

Clinical review: Long-term noninvasive ventilation  

PubMed Central

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.

Robert, Dominique; Argaud, Laurent

2007-01-01

356

Open lung approach with low tidal volume mechanical ventilation attenuates lung injury in rats with massive brain damage  

PubMed Central

Introduction The ideal ventilation strategy for patients with massive brain damage requires better elucidation. We hypothesized that in the presence of massive brain injury, a ventilation strategy using low (6 milliliters per kilogram ideal body weight) tidal volume (VT) ventilation with open lung positive end-expiratory pressure (LVT/OLPEEP) set according to the minimal static elastance of the respiratory system, attenuates the impact of massive brain damage on gas-exchange, respiratory mechanics, lung histology and whole genome alterations compared with high (12 milliliters per kilogram ideal body weight) VT and low positive end-expiratory pressure ventilation (HVT/LPEEP). Methods In total, 28 adult male Wistar rats were randomly assigned to one of four groups: 1) no brain damage (NBD) with LVT/OLPEEP; 2) NBD with HVT/LPEEP; 3) brain damage (BD) with LVT/OLPEEP; and 4) BD with HVT/LPEEP. All animals were mechanically ventilated for six hours. Brain damage was induced by an inflated balloon catheter into the epidural space. Hemodynamics was recorded and blood gas analysis was performed hourly. At the end of the experiment, respiratory system mechanics and lung histology were analyzed. Genome wide gene expression profiling and subsequent confirmatory quantitative polymerase chain reaction (qPCR) for selected genes were performed. Results In NBD, both LVT/OLPEEP and HVT/LPEEP did not affect arterial blood gases, as well as whole genome expression changes and real-time qPCR. In BD, LVT/OLPEEP, compared to HVT/LPEEP, improved oxygenation, reduced lung damage according to histology, genome analysis and real-time qPCR with decreased interleukin 6 (IL-6), cytokine-induced neutrophil chemoattractant 1 (CINC)-1 and angiopoietin-4 expressions. LVT/OLPEEP compared to HVT/LPEEP improved overall survival. Conclusions In BD, LVT/OLPEEP minimizes lung morpho-functional changes and inflammation compared to HVT/LPEEP.

2014-01-01

357

Rural health care support mechanism. Final rule.  

PubMed

In this document, the Federal Communications Commission reforms its universal service support program for health care, transitioning its existing Internet Access and Rural Health Care Pilot programs into a new, efficient Healthcare Connect Fund. This Fund will expand health care provider access to broadband, especially in rural areas, and encourage the creation of state and regional broadband health care networks. Access to broadband for medical providers saves lives while lowering health care costs and improving patient experiences. PMID:23476995

2013-03-01

358

A rational framework for selecting modes of ventilation.  

PubMed

Mechanical ventilation is a life-saving intervention for respiratory failure and thus has become the cornerstone of the practice of critical care medicine. A mechanical ventilation mode describes the predetermined pattern of patient-ventilator interaction. In recent years there has been a dizzying proliferation of mechanical ventilation modes, driven by technological advances and market pressures, rather than clinical data. The comparison of these modes is hampered by the sheer number of combinations that need to be tested against one another, as well as the lack of a coherent, logical nomenclature that accurately describes a mode. In this paper we propose a logical nomenclature for mechanical ventilation modes, akin to biological taxonomy. Accordingly, the control variable, breath sequence, and targeting schemes for the primary and secondary breaths represent the order, family, genus, and species, respectively, for the described mode. To distinguish unique operational algorithms, a fifth level of distinction, termed variety, is utilized. We posit that such coherent ordering would facilitate comparison and understanding of modes. Next we suggest that the clinical goals of mechanical ventilation may be simplified into 3 broad categories: provision of safe gas exchange; provision of comfort; and promotion of liberation from mechanical ventilation. Safety is achieved via optimization of ventilation-perfusion matching and pressure-volume relationship of the lungs. Comfort is provided by fostering patient-ventilator synchrony. Liberation is promoted by optimization of the weaning experience. Then we follow a paradigm that matches the technological capacity of a particular mode to achieving a specific clinical goal. Finally, we provide the reader with a comparison of existing modes based on these principles. The status quo in mechanical ventilation mode nomenclature impedes communication and comparison of existing mechanical ventilation modes. The proposed model, utilizing a systematic nomenclature, provides a useful framework to address this unmet need. PMID:22710796

Mireles-Cabodevila, Eduardo; Hatipo?lu, Umur; Chatburn, Robert L

2013-02-01

359

Home mechanical ventilation in the aftermath of the Hanshin-Awaji earthquake disaster.  

PubMed

Children who were dependent upon home mechanical ventilation (HMV), suffered in various ways from the disastrous Hanshin-Awaji earthquake disaster. The earthquake abruptly cut the supplies of water, gas and electricity, causing intense anxiety for those families. Through loss of the respirator function, some of them experienced an unexpected catastrophe. In the disaster area, there were children who were dependent upon HMV (19 cases) and children who were preparing for HMV in hospitals (nine cases). Information was gathered from questionnaires about the disaster, communication and correspondence with families. None of the 28 cases died or were injured. Nineteen cases had a variety of problems. In eight cases, respiratory support problems were acute. Nevertheless, all of them survived the crisis successfully even in the midst of such a catastrophic situation. An organization of HMV children's families, called the Baku-Baku Club, helped families with HMV problems by supplying water, food, oxygen and compressed air cylinders among other things. Additional outside batteries for portable respirators are essential equipment for HMV, especially for emergencies. A manual for clarifying the system for support in the Baku-Baku Club and a registration system for public medical service should be established in preparation for such a crisis. PMID:8775564

Shimada, S; Funato, M

1995-12-01

360

Effects of age on the synergistic interactions between lipopolysaccharide and mechanical ventilation in mice.  

PubMed

Children have a lower incidence and mortality from acute lung injury (ALI) than adults, and infections are the most common event associated with ALI. To study the effects of age on susceptibility to ALI, we investigated the responses to microbial products combined with mechanical ventilation (MV) in juvenile (21-d-old) and adult (16-wk-old) mice. Juvenile and adult C57BL/6 mice were treated with inhaled Escherichia coli 0111:B4 lipopolysaccharide (LPS) and MV using tidal volume = 15 ml/kg. Comparison groups included mice treated with LPS or MV alone and untreated age-matched control mice. In adult animals treated for 3 hours, LPS plus MV caused synergistic increases in neutrophils (P < 0.01) and IgM in bronchoalveolar lavage fluid (P = 0.03) and IL-1? in whole lung homogenates (P < 0.01) as compared with either modality alone. Although juvenile and adult mice had similar responses to LPS or MV alone, the synergistic interactions between LPS and MV did not occur in juvenile mice. Computational analysis of gene expression array data suggest that the acquisition of synergy with increasing age results, in part, from the loss of antiapoptotic responses and the acquisition of proinflammatory responses to the combination of LPS and MV. These data suggest that the synergistic inflammatory and injury responses to inhaled LPS combined with MV are acquired with age as a result of coordinated changes in gene expression of inflammatory, apoptotic, and TGF-? pathways. PMID:19901347

Smith, Lincoln S; Gharib, Sina A; Frevert, Charles W; Martin, Thomas R

2010-10-01

361

Pulmonary matrix metalloproteinase-9 activity in mechanically ventilated children with respiratory syncytial virus.  

PubMed

Respiratory syncytial virus (RSV) infection is a potent stimulus for airway epithelial expression of matrix metalloproteinase (MMP)-9. MMP-9 activity in vivo is a predictor of disease severity in children with RSV-induced respiratory failure. Human airway epithelial cells were infected with RSV A2 strain and analysed for MMP-9 and tissue inhibitor of metalloproteinase (TIMP)-1 (a natural inhibitor of MMP-9) release. In addition, endotracheal samples from children with RSV-RF and controls (non-RSV pneumonia and nonlung disease controls) were analysed for MMP-9, TIMP-1, human neutrophil elastase and myeloperoxidase activity. RSV infection of airway epithelia was sufficient to rapidly induce MMP-9 transcription and protein release. Pulmonary MMP-9 activity peaked at 48 h in infants with RSV-induced respiratory failure. In the RSV group, MMP-9 activity and MMP-9/TIMP-1 ratio imbalance predicted higher oxygen requirement and worse paediatric risk of mortality scores. The highest levels of human neutrophil elastase and myeloperoxidase activity were measured in the RSV cohort; however, unlike MMP-9, these neutrophil markers failed to predict disease severity. These results support the hypothesis that RSV is a potent stimulus for MMP-9 expression and release from human airway epithelium, and that MMP-9 is an important biomarker of disease severity in mechanically ventilated children with RSV lung infection. PMID:24311764

Kong, Michele Y F; Clancy, John P; Peng, Ning; Li, Yao; Szul, Tomasz J; Xu, Xin; Oster, Robert; Sullender, Wayne; Ambalavanan, Namasivayam; Blalock, J Edwin; Gaggar, Amit

2014-04-01

362

Pulmonary MMP-9 Activity in Mechanically Ventilated Children with RSV Disease  

PubMed Central

Hypothesis RSV infection is a potent stimulus for airway epithelial expression of MMP-9, and MMP-9 activity in vivo is a predictor of disease severity in children with RSV-induced respiratory failure (RSV-RF). Methods Human airway epithelial cells were infected with RSV A2 strain, and analyzed for MMP-9 and tissue inhibitor of metalloproteinases-1 (TIMP-1, a natural inhibitor of MMP-9) release. In addition, endotracheal samples from children with RSV-RF and controls (non-RSV pneumonia and non-lung disease controls) were analyzed for MMP-9, TIMP-1, human neutrophil elastase (HNE) and myeloperoxidase (MPO) activity. Results RSV infection of airway epithelia was sufficient to rapidly induce MMP-9 transcription and protein release. Pulmonary MMP-9 activity peaked at 48 hours in infants with RSV-RF compared to controls. In the RSV group, MMP-9 activity and MMP-9:TIMP-1 ratio imbalance predicted higher oxygen requirement and worse Pediatric Risk of Mortality scores. Highest levels of HNE and MPO were measured in the RSV cohort but unlike MMP-9, these neutrophil markers failed to predict disease severity. Conclusions These results support the hypothesis that RSV is a potent stimulus for MMP-9 expression and release from human airway epithelium, and that MMP-9 is an important biomarker of disease severity in mechanically ventilated children with RSV lung infection.

Kong, Michele YF; Clancy, JP; Peng, Ning; Li, Yao; Szul, Tomasz; Xu, Xin; Oster, Robert; Sullender, Wayne; Ambalavanan, Namasivayam; Blalock, J. Edwin; Gaggar, Amit

2014-01-01

363

Postnatal diuresis and respiratory distress syndrome in infants receiving mechanical ventilation.  

PubMed

Measurements of body water homeostasis and pulmonary function were obtained in 24 infants with respiratory distress syndrome requiring mechanical ventilation during the first five days of life to determine the relationship of diuresis to improvement in pulmonary function. Initial diuresis (output intake ratio greater than 0.8) occurred at 24 hours, maximum diuresis (output intake ratio greater than or equal to 1.6) at 40 hours, and initial improvement in pulmonary function (fall in AaDO2 greater than 50 mm Hg) at 48 hours. Urine flow rates over four-, eight-, or 12-hour periods were quite variable and correlated poorly with improvement in pulmonary function. Reduction in body weight was a more accurate indicator of total changes in body water than urine output, output intake ratio, or fractional excretion of sodium. Although there was a temporal relationship of loss of body water and improvement in pulmonary function by analysis of means, no cause-and-effect relationship could be found on a case-by-case analysis. Five of 24 infants demonstrated improvement in pulmonary function prior to diuresis or reduction in body weight. Nine infants had a diuresis more than 24 hours prior to pulmonary improvement, and two infants had a diuresis without pulmonary improvement during the five-day study period. These data indicate that factors other than body water are associated with improvement in pulmonary function in infants with respiratory distress syndrome. PMID:6525208

Shaffer, S G; Glenski, J A; Callenbach, J C; Hall, F K; Sheehan, M B; Thibeault, D W; Hall, R T

1984-04-01

364

Diaphragm ultrasound as a new index of discontinuation from mechanical ventilation  

PubMed Central

Background Predictive indexes of weaning from mechanical ventilation are often inaccurate. Among the many indexes used in clinical practice, the rapid shallow breathing index is one of the most accurate. We evaluated a new weaning index consisting in the diaphragm thickening fraction (DTF) assessed by ultrasound. Methods Forty-six patients were prospectively enrolled. All patients were ventilated in pressure support through a tracheostomy tube. Patients underwent a spontaneous breathing trial (SBT) when they met all the following criteria: FiO2??200, respiratory rate <30 breaths per minute, absence of fever, alert and cooperative, and hemodynamic stability without vaso-active therapy support. During the trial, the right hemi-diaphragm was visualized in the zone of apposition using a 10-MHz linear ultrasound probe. The patient was then instructed to perform breathing to total lung capacity (TLC) and then exhaling to residual volume (RV). Diaphragm thickness was recorded at TLC and RV, and the DTF was calculated as percentage from the following formula: Thickness at end inspiration?-?Thickness at end expiration / Thickness at end expiration. Also, the rapid shallow breathing index (RSBI) was calculated. Weaning failure was defined as the inability to maintain spontaneous breathing for at least 48 h, without any form of ventilatory support. Results A significant difference between diaphragm thickness at TLC and RV was observed both in patients who succeeded SBT and patients who failed. DTF was significantly different between patients who failed and patients who succeeded SBT. A cutoff value of a DTF >36% was associated with a successful SBT with a sensitivity of 0.82, a specificity of 0.88, a positive predictive value (PPV) of 0.92, and a negative predictive value (NPV) of 0.75. By comparison, RSBI <105 had a sensitivity of 0.93, a specificity of 0.88, a PPV of 0.93, and a NPV of 0.88 for determining SBT success. Conclusions This study shows that in our cohort of patients, the assessment of DTF by diaphragm ultrasound may perform similarly to other weaning indexes. If validated by other studies, this method may be used in clinical practice.

2014-01-01

365

Physiological effects of flow and pressure triggering during non- invasive mechanical ventilation in patients with chronic obstructive pulmonary disease  

PubMed Central

BACKGROUND: The effect of the type of trigger system on inspiratory effort has been studied in intubated patients, but no data are available in non-invasive mechanical ventilation where the "trigger variable" may be even more important since assisted modes of ventilation are often employed from the beginning of mechanical ventilation. METHODS: The effect of flow triggering (1 and 5 1/min) and pressure triggering (-1 cm H2O) on inspiratory effort during pressure support ventilation (PSV) and assisted controlled mode (A/C) delivered non-invasively with a full face mask were compared in patients with chronic obstructive pulmonary disease (COPD) recovering from an acute exacerbation. The patients were studied during randomised 15 minute runs at zero positive end expiratory pressure (ZEEP). The oesophageal pressure time product (PTPoes), dynamic intrinsic PEEP (PEEPi,dyn), fall in maximal airway pressure (delta Paw) during inspiration, and ventilatory variables were measured. RESULTS: Minute ventilation, respiratory pattern, dynamic lung compliance and resistances, and changes in end expiratory lung volume (delta EELV) were the same with the two triggering systems. The total PTPoes and its pre-triggering phase (PTP due to PEEPi and PTP due to valve opening) were significantly higher during both PSV and A/C with pressure triggering than with flow triggering at both levels of sensitivity. delta Paw was larger during pressure triggering, and PEEPi,dyn was significantly reduced during flow triggering in the A/C mode only. CONCLUSIONS: In patients with COPD flow triggering reduces the inspiratory effort during both PSV and A/C modes compared with pressure triggering. These findings are likely to be due to a reduction in PEEPi,dyn and in the time of valve opening with a flow trigger. ???

Nava, S.; Ambrosino, N.; Bruschi, C.; Confalonieri, M.; Rampulla, C.

1997-01-01

366

Effect of dynamic random leaks on the monitoring accuracy of home mechanical ventilators: a bench study  

PubMed Central

Background So far, the accuracy of tidal volume (VT) and leak measures provided by the built-in software of commercial home ventilators has only been tested using bench linear models with fixed calibrated and continuous leaks. The objective was to assess the reliability of the estimation of tidal volume (VT) and unintentional leaks in a single tubing bench model which introduces random dynamic leaks during inspiratory or expiratory phases. Methods The built-in software of four commercial home ventilators and a fifth ventilator-independent ad hoc designed external software tool were tested with two levels of leaks and two different models with excess leaks (inspiration or expiration). The external software analyzed separately the inspiratory and expiratory unintentional leaks. Results In basal condition, all ventilators but one underestimated tidal volume with values ranging between -1.5?±?3.3% to -8.7%?±?3.27%. In the model with excess of inspiratory leaks, VT was overestimated by all four commercial software tools, with values ranging from 18.27?±?7.05% to 35.92?±?17.7%, whereas the ventilator independent-software gave a smaller difference (3.03?±?2.6%). Leaks were underestimated by two applications with values of -11.47?±?6.32 and -5.9?±?0.52 L/min. With expiratory leaks, VT was overestimated by the software of one ventilator and the ventilator-independent software and significantly underestimated by the other three, with deviations ranging from +10.94?±?7.1 to -48?±?23.08%. The four commercial tools tested overestimated unintentional leaks, with values between 2.19?±?0.85 to 3.08?±?0.43 L/min. Conclusions In a bench model, the presence of unintentional random leaks may be a source of error in the measurement of VT and leaks provided by the software of home ventilators. Analyzing leaks during inspiration and expiration separately may reduce this source of error.

2013-01-01

367

Water accumulation in metered dose inhaler spacers under normal mechanical ventilation conditions  

Microsoft Academic Search

Objective: The purpose of this study was to compare the water accumulation in 3 types of metered dose inhaler (MDI) spacer shapes in-line in a ventilator circuit, in 2 positions over 2-, 4-, and 6-hour time periods through the use of heated- and nonheated-wire ventilator circuits. Design: The study design was prospective, quasiexperimental, and random assignment. Setting: The study was

Jonathan B. Waugh; John B. Waugh

2000-01-01

368

Air Distribution Effectiveness for Residential Mechanical Ventilation: Simulation and Comparison of Normalized Exposures  

SciTech Connect

The purpose of ventilation is to dilute indoor contaminants that an occupant is exposed to. Even when providing the same nominal rate of outdoor air, different ventilation systems may distribute air in different ways, affecting occupants' exposure to household contaminants. Exposure ultimately depends on the home being considered, on source disposition and strength, on occupants' behavior, on the ventilation strategy, and on operation of forced air heating and cooling systems. In any multi-zone environment dilution rates and source strengths may be different in every zone and change in time, resulting in exposure being tied to occupancy patterns.This paper will report on simulations that compare ventilation systems by assessing their impact on exposure by examining common house geometries, contaminant generation profiles, and occupancy scenarios. These simulations take into account the unsteady, occupancy-tied aspect of ventilation such as bathroom and kitchen exhaust fans. As most US homes have central HVAC systems, the simulation results will be used to make appropriate recommendations and adjustments for distribution and mixing to residential ventilation standards such as ASHRAE Standard 62.2.This paper will report on work being done to model multizone airflow systems that are unsteady and elaborate the concept of distribution matrix. It will examine several metrics for evaluating the effect of air distribution on exposure to pollutants, based on previous work by Sherman et al. (2006).

Petithuguenin, T.D.P.; Sherman, M.H.

2009-05-01

369

Proportional mechanical ventilation through PWM driven on/off solenoid valve.  

PubMed

Proportional strategies for artificial ventilation are the most recent form of synchronized partial ventilatory assistance and intra-breath control techniques available in clinical practice. Currently, the majority of commercial ventilators allowing proportional ventilation uses proportional valves to generate the flow rate pattern. This paper proposes on-off solenoid valves for proportional ventilation given their small size, low cost and short switching time, useful for supplying high frequency ventilation. A new system based on a novel fast switching driver circuit combined with on/off solenoid valve is developed. The average short response time typical of onoff solenoid valves was further reduced through the driving circuit for the implementation of PWM control. Experimental trials were conducted for identifying the dynamic response of the PWM driven on/off valve and for verifying its effectiveness in generating variable-shaped ventilatory flow rate patterns. The system was able to smoothly follow the reference flow rate patterns also changing in time intervals as short as 20 ms, achieving a flow rate resolution up to 1 L/min and repeatability in the order of 0.5 L/min. Preliminary results showed the feasibility of developing a stand alone portable device able to generate both proportional and high frequency ventilation by only using on-off solenoid valves. PMID:21096120

Sardellitti, I; Cecchini, S; Silvestri, S; Caldwell, D G

2010-01-01

370

Protective lung ventilation in operating room: a systematic review.  

PubMed

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 clinic