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Sample records for prolonged mechanical ventilation

  1. Bilateral Scapulohumeral Ankylosis after Prolonged Mechanical Ventilation.

    PubMed

    van Lotten, Manon L; Schreinemakers, J Rieneke; van Noort, Arthur; Rademakers, Maarten V

    2016-09-01

    This case demonstrates a rarely reported bilateral scapulohumeral bony ankylosis. A young woman developed extensive heterotopic ossifications (HOs) in both shoulder joints after being mechanically ventilated for several months at the intensive care unit in a comatose status. She presented with a severe movement restriction of both shoulder joints. Surgical resection of the bony bridges was performed in 2 separate sessions with a significant improvement of shoulder function afterwards. No postoperative complications, pain, or recurrence of HOs were noted at 1-year follow-up. Mechanical ventilation, immobilization, neuromuscular blockage, and prolonged sedation are known risk factors for the development of HOs in the shoulder joints. Relatively early surgical resection of the HOs can be performed safely in contrary to earlier belief. Afterwards, nonsteroidal anti-inflammatory drugs and/or radiation therapy can be possible treatment modalities to prevent recurrence of HOs. PMID:27583120

  2. Bilateral Scapulohumeral Ankylosis after Prolonged Mechanical Ventilation

    PubMed Central

    Schreinemakers, J. Rieneke; van Noort, Arthur; Rademakers, Maarten V.

    2016-01-01

    This case demonstrates a rarely reported bilateral scapulohumeral bony ankylosis. A young woman developed extensive heterotopic ossifications (HOs) in both shoulder joints after being mechanically ventilated for several months at the intensive care unit in a comatose status. She presented with a severe movement restriction of both shoulder joints. Surgical resection of the bony bridges was performed in 2 separate sessions with a significant improvement of shoulder function afterwards. No postoperative complications, pain, or recurrence of HOs were noted at 1-year follow-up. Mechanical ventilation, immobilization, neuromuscular blockage, and prolonged sedation are known risk factors for the development of HOs in the shoulder joints. Relatively early surgical resection of the HOs can be performed safely in contrary to earlier belief. Afterwards, nonsteroidal anti-inflammatory drugs and/or radiation therapy can be possible treatment modalities to prevent recurrence of HOs. PMID:27583120

  3. Prolonged Mechanical Ventilation (PMV): When is it Justified in ICU?

    PubMed

    Trivedi, Trupti H

    2015-10-01

    Over years, the number of patients requiring prolonged mechanical ventilation (PMV) in ICU has increased. Trends in the numbers of patients requiring PMV are of interest to health service planners because they consume a disproportionate amount of healthcare resources, and have high illness costs.1 PMV is defined as need of invasive mechanical ventilation for consecutive 21 days for at least 6 hours per day. With improvement in ICU care more patients survive acute respiratory failure and with that number of patients requiring PMV is likely to increase further. In a large multi centric study in United Kingdom the incidence PMV was 4.4 per 100 ICU admissions, and 6.3 per 100 ventilated ICU admissions. Also these patients used 29.1% of all general ICU bed days, had longer hospital stay after ICU discharge than non-PMV patients and had higher hospital mortality (40.3% vs 33.8%, P = 0.02).2. PMID:27608685

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

    PubMed

    Hess, Dean R

    2012-06-01

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

  5. Early Rehabilitation Therapy Is Beneficial for Patients With Prolonged Mechanical Ventilation After Coronary Artery Bypass Surgery.

    PubMed

    Dong, Zehua; Yu, Bangxu; Zhang, Quanfang; Pei, Haitao; Xing, Jinyan; Fang, Wei; Sun, Yunbo; Song, Zhen

    2016-01-01

    We investigated the effects of early rehabilitation therapy on prolonged mechanically ventilated patients after coronary artery bypass surgery (CABG).A total of 106 patients who underwent CABG between June 2012 and May 2015 were enrolled and randomly assigned into an early rehabilitation group (53 cases) and a control group (53 cases). The rehabilitation therapy consisted of 6 steps including head up, transferring from supination to sitting, sitting on the edge of bed, sitting in a chair, transferring from sitting to standing, and walking along a bed. The patients received rehabilitation therapy in the intensive care unit (ICU) after CABG in the early rehabilitation group. The control group patients received rehabilitation therapy after leaving the ICU.The results showed that the early rehabilitation therapy could significantly decrease the duration of mechanical ventilation (early rehabilitation group: 8.1 ± 3.3 days; control group: 13.9 ± 4.1 days, P < 0.01), hospital stay (early rehabilitation group: 22.0 ± 3.8 days; control group: 29.1 ± 4.6 days, P < 0.01), and ICU stay (early rehabilitation group: 11.7 ± 3.2 days; control group: 18.3 ± 4.2 days, P < 0.01) for patients requiring more than 72 hours prolonged mechanical ventilation. The results of Kaplan-Meier analysis showed that the proportions of patients remaining on mechanical ventilation in the early rehabilitation group were larger than that in the control group after 7 days of rehabilitation therapy (logrank test: P < 0.01). The results provide evidence for supporting the application of early rehabilitation therapy in patients requiring prolonged mechanical ventilation after CABG. PMID:26973269

  6. Incidence and risk factors of prolonged mechanical ventilation in neuromuscular scoliosis surgery.

    PubMed

    Udink ten Cate, Floris E A; van Royen, Barend J; van Heerde, Marc; Roerdink, Dianne; Plötz, Frans B

    2008-07-01

    Patients with neuromuscular scoliosis (NMS) are frequently considered at high risk for postoperative complications based on their underlying disease and comorbidities. Postoperative complications include prolonged mechanical ventilation (MV), defined longer than 72 h, at the paediatric intensive care unit. The objectives of this retrospective study were to assess the incidence of prolonged MV in patients with NMS following scoliosis surgery and to identify predictive risk factors. A total of 46 consecutive patients underwent surgical spinal fusion and instrumentation for progressive NMS. Prolonged MV was required in seven of 46 patients (15%). The only risk factor for prolonged MV was a decreased preoperative pulmonary function. Forced expired volume in 1 s and vital capacity were significantly decreased in patients with MV >72 h compared with patients with MV <72 h. Routine preoperative pulmonary function testing may reveal important information with regard to restrictive lung disease in the preoperative assessment of patients with NMS and predict the early postoperative clinical course. PMID:18525479

  7. The outcomes and prognostic factors of patients requiring prolonged mechanical ventilation

    PubMed Central

    Lai, Chih-Cheng; Shieh, Jiunn-Min; Chiang, Shyh-Ren; Chiang, Kuo-Hwa; Weng, Shih-Feng; Ho, Chung-Han; Tseng, Kuei-Ling; Cheng, Kuo-Chen

    2016-01-01

    The aims of this study were to investigate the outcomes of patients requiring prolonged mechanical ventilation (PMV) and to identify risk factors associated with its mortality rate. All patients admitted to the respiratory care centre (RCC) who required PMV (the use of MV ≥21 days) between January 2006 and December 2014 were enrolled. A total of 1,821 patients were identified; their mean age was 69.8 ± 14.2 years, and 521 patients (28.6%) were aged >80 years. Upon RCC admission, the APACHE II scores were 16.5 ± 6.3, and 1,311 (72.0%) patients had at least one comorbidity. Pulmonary infection was the most common diagnosis (n = 770, 42.3%). A total of 320 patients died during hospitalization, and the in-hospital mortality rate was 17.6%. A multivariate stepwise logistic regression analysis indicated that patients were more likely to die if they who were >80 years of age, had lower albumin levels (<2 g/dl) and higher APACHE II scores (≥15), required haemodialysis, or had a comorbidity. In conclusion, the in-hospital mortality for patients requiring PMV in our study was 17%, and mortality was associated with disease severity, hypoalbuminaemia, haemodialysis, and an older age. PMID:27296248

  8. The outcomes and prognostic factors of patients requiring prolonged mechanical ventilation.

    PubMed

    Lai, Chih-Cheng; Shieh, Jiunn-Min; Chiang, Shyh-Ren; Chiang, Kuo-Hwa; Weng, Shih-Feng; Ho, Chung-Han; Tseng, Kuei-Ling; Cheng, Kuo-Chen

    2016-01-01

    The aims of this study were to investigate the outcomes of patients requiring prolonged mechanical ventilation (PMV) and to identify risk factors associated with its mortality rate. All patients admitted to the respiratory care centre (RCC) who required PMV (the use of MV ≥21 days) between January 2006 and December 2014 were enrolled. A total of 1,821 patients were identified; their mean age was 69.8 ± 14.2 years, and 521 patients (28.6%) were aged >80 years. Upon RCC admission, the APACHE II scores were 16.5 ± 6.3, and 1,311 (72.0%) patients had at least one comorbidity. Pulmonary infection was the most common diagnosis (n = 770, 42.3%). A total of 320 patients died during hospitalization, and the in-hospital mortality rate was 17.6%. A multivariate stepwise logistic regression analysis indicated that patients were more likely to die if they who were >80 years of age, had lower albumin levels (<2 g/dl) and higher APACHE II scores (≥15), required haemodialysis, or had a comorbidity. In conclusion, the in-hospital mortality for patients requiring PMV in our study was 17%, and mortality was associated with disease severity, hypoalbuminaemia, haemodialysis, and an older age. PMID:27296248

  9. Upper extremity muscle tone and response of tidal volume during manually assisted breathing for patients requiring prolonged mechanical ventilation

    PubMed Central

    Morino, Akira; Shida, Masahiro; Tanaka, Masashi; Sato, Kimihiro; Seko, Toshiaki; Ito, Shunsuke; Ogawa, Shunichi; Yokoi, Yuka; Takahashi, Naoaki

    2015-01-01

    [Purpose] The aim of the present study was to examine, in patients requiring prolonged mechanical ventilation, if the response of tidal volume during manually assisted breathing is dependent upon both upper extremity muscle tone and the pressure intensity of manually assisted breathing. [Subjects] We recruited 13 patients on prolonged mechanical ventilation, and assessed their upper extremity muscle tone using the modified Ashworth scale (MAS). The subjects were assigned to either the low MAS group (MAS≤2, n=7) or the high MAS group (MAS≥3, n=6). [Methods] The manually assisted breathing technique was applied at a pressure of 2 kgf and 4 kgf. A split-plot ANOVA was performed to compare the tidal volume of each pressure during manually assisted breathing between the low and the high MAS groups. [Results] Statistical analysis showed there were main effects of the upper extremity muscle tone and the pressure intensity of the manually assisted breathing technique. There was no interaction between these factors. [Conclusion] Our findings reveal that the tidal volume during the manually assisted breathing technique for patients with prolonged mechanical ventilation depends upon the patient’s upper extremity muscle tone and the pressure intensity. PMID:26357431

  10. Perioperative risk factors for prolonged mechanical ventilation and tracheostomy in women undergoing coronary artery bypass graft with cardiopulmonary bypass

    PubMed Central

    Faritous, Zahra S.; Aghdaie, Nahid; Yazdanian, Forouzan; Azarfarin, Rasoul; Dabbagh, Ali

    2011-01-01

    Background: Prolonged mechanical ventilation is an important recognized complication occurring during cardiovascular surgery procedures. This study was done to assess the perioperative risk factors related to postoperative pulmonary complications and tracheostomy in women undergoing coronary artery bypass graft with cardiopulmonary bypass. Methods: It was a retrospective study on 5,497 patients, including 31 patients with prolonged ventilatory support and 5,466 patients without it; from the latter group, 350 patients with normal condition (extubated in 6-8 hours without any complication) were selected randomly. Possible perioperative risk factors were compared between the two groups using a binary logistic regression model. Results: Among the 5,497 women undergoing coronary artery bypass graft (CABG), 31 women needed prolonged mechanical ventilation (PMV), and 15 underwent tracheostomy. After logistic regression, 7 factors were determined as being independent perioperative risk factors for PMV. Discussion: Age ≥70 years old, left ventricular ejection fraction (LVEF) ≤30%, preexisting respiratory or renal disease, emergency or re-do operation and use of preoperative inotropic agents are the main risk factors determined in this study on women undergoing CABG. PMID:21804797

  11. Effects of Lung Expansion Therapy on Lung Function in Patients with Prolonged Mechanical Ventilation

    PubMed Central

    Chen, Yen-Huey; Yeh, Ming-Chu; Hu, Han-Chung; Lee, Chung-Shu; Li, Li-Fu; Chen, Ning-Hung; Huang, Chung-Chi; Kao, Kuo-Chin

    2016-01-01

    Common complications in PMV include changes in the airway clearance mechanism, pulmonary function, and respiratory muscle strength, as well as chest radiological changes such as atelectasis. Lung expansion therapy which includes IPPB and PEEP prevents and treats pulmonary atelectasis and improves lung compliance. Our study presented that patients with PMV have improvements in lung volume and oxygenation after receiving IPPB therapy. The combination of IPPB and PEEP therapy also results in increase in respiratory muscle strength. The application of IPPB facilitates the homogeneous gas distribution in the lung and results in recruitment of collapsed alveoli. PEEP therapy may reduce risk of respiratory muscle fatigue by preventing premature airway collapse during expiration. The physiologic effects of IPPB and PEEP may result in enhancement of pulmonary function and thus increase the possibility of successful weaning from mechanical ventilator during weaning process. For patients with PMV who were under the risk of atelectasis, the application of IPPB may be considered as a supplement therapy for the enhancement of weaning outcome during their stay in the hospital.

  12. Mechanical ventilation in children.

    PubMed

    Kendirli, Tanil; Kavaz, Asli; Yalaki, Zahide; Oztürk Hişmi, Burcu; Derelli, Emel; Ince, Erdal

    2006-01-01

    Mechanical ventilation can be lifesaving, but > 50% of complications in conditions that require intensive care are related to ventilatory support, particularly if it is prolonged. We retrospectively evaluated the medical records of patients who had mechanical ventilation in the Pediatric Intensive Care Unit (PICU) during a follow-up period between January 2002-May 2005. Medical records of 407 patients were reviewed. Ninety-one patients (22.3%) were treated with mechanical ventilation. Ages of all patients were between 1-180 (median: 8) months. The mechanical ventilation time was 18.8 +/- 14.1 days. Indication of mechanical ventilation could be divided into four groups as respiratory failure (64.8%), cardiovascular failure (19.7%), central nervous system disease (9.8%) and safety airway (5.4%). Tracheostomy was performed in four patients. The complication ratio of mechanically ventilated children was 42.8%, and diversity of complications was as follows: 26.3% atelectasia, 17.5% ventilator-associated pneumonia, 13.1% pneumothorax, 5.4% bleeding, 4.3% tracheal edema, and 2.1% chronic lung disease. The mortality rate of mechanically ventilated patients was 58.3%, but the overall mortality rate in the PICU was 12.2%. In conclusion, there are few published epidemiological data on the follow-up results and mortality in infants and children who are mechanically ventilated. PMID:17290566

  13. Clinical presentations as predictors of prolonged mechanical ventilation in Guillain-Barré syndrome in an institution with limited medical resources

    PubMed Central

    Toamad, Umarudee; Kongkamol, Chanon; Setthawatcharawanich, Suwanna; Limapichat, Kitti; Phabphal, Kanitpong; Sathirapanya, Pornchai

    2015-01-01

    INTRODUCTION Severe Guillain-Barré syndrome (GBS) causes ventilatory insufficiency and the need for prolonged artificial ventilation. Under circumstances where medical care for patients with severe GBS is required in a resource-limited institution, identifying initial clinical presentations in GBS patients that can predict respiratory insufficiency and the need for prolonged mechanical ventilation (> 15 days) may be helpful for advanced care planning. METHODS The medical records of patients diagnosed with GBS in a tertiary care and medical teaching hospital from January 2001 to December 2010 were retrospectively reviewed. The demographic data and clinical presentations of the patients were summarised using descriptive statistics. Clinical predictors of respiratory insufficiency and the need for prolonged mechanical ventilation (> 15 days) were identified using univariate logistic regression analysis. RESULTS A total of 55 patients with GBS were included in this study. Mechanical ventilation was needed in 28 (50.9%) patients. Significant clinical predictors for respiratory insufficiency were bulbar muscle weakness (odds ratio [OR] 5.08, 95% confidence interval [CI] 1.31–21.60, p = 0.007) and time to peak limb weakness ≤ 5 days (OR 0.75, 95% CI 0.62–0.91, p < 0.001). Bulbar muscle weakness (p = 0.006) and time to peak limb weakness ≤ 5 days (p < 0.001) were also found to be significantly associated with the need for prolonged mechanical ventilation (> 15 days). CONCLUSION Bulbar weakness and time to peak limb weakness ≤ 5 days were able to predict respiratory insufficiency and the need for prolonged mechanical ventilation in patients with GBS. PMID:26512148

  14. A randomized clinical trial of neurally adjusted ventilatory assist versus conventional weaning mode in patients with COPD and prolonged mechanical ventilation

    PubMed Central

    Kuo, Nai-Ying; Tu, Mei-Lien; Hung, Tsai-Yi; Liu, Shih-Feng; Chung, Yu-Hsiu; Lin, Meng-Chih; Wu, Chao-Chien

    2016-01-01

    Background Patient-ventilator asynchrony is a common problem in mechanically ventilated patients; the problem is especially obvious in COPD. Neutrally adjusted ventilatory assist (NAVA) can improve patient-ventilator asynchrony; however, the effect in COPD patients with prolonged mechanical ventilation is still unknown. The goals of this study are to evaluate the effect of NAVA and conventional weaning mode in patients with COPD during prolonged mechanical ventilation. Methods The study enrolled a total of 33 COPD patients with ventilator dependency for more than 21 days in the weaning center. A diaphragm electrical activity (Edi) catheter was inserted in patients within 24 hours after admission to the respiratory care center, and patients were randomly allocated to NAVA or conventional group. A spontaneous breathing trial was performed every 24 hours. The results correlated with the clinical parameters. Results There were significantly higher asynchrony incidence rates in the whole group after using Edi catheter (before vs post-Edi catheter insertion =60.6% vs 87.9%, P<0.001). Asynchrony index: before vs post-Edi catheter insertion =7.4%±8.5% vs 13.2%±13.5%, P<0.01. Asynchrony incidence: NAVA vs conventional =0% vs 84.2%, P<0.001. Asynchrony index: NAVA vs conventional =0 vs 11.9±11.2 (breath %), P<0.001. The most common asynchrony events were ineffective trigger and delayed trigger. Conclusion Compared to conventional mode, NAVA mode can significantly enhance respiratory monitoring and improve patient-ventilator interaction in COPD patients with prolonged mechanical ventilation in respiratory care center. PMID:27274216

  15. School Achievements, Behavioural Adjustments and Health at Nine Years of Age in a Population of Infants Who Were Born Preterm or Required Prolonged Mechanical Ventilation.

    ERIC Educational Resources Information Center

    Mohay, Heather; And Others

    The prevalence of subtle handicapping conditions, such as learning disabilities, behavior problems, and recurrent illness, in a population of 88 high-risk infants was investigated when the children reached 9 years of age. Infants had had birthweights of less than 1500 grams or had required prolonged mechanical ventilation in the neonatal period.…

  16. The Outcomes and Prognostic Factors of the Very Elderly Requiring Prolonged Mechanical Ventilation in a Single Respiratory Care Center

    PubMed Central

    Lai, Chih-Cheng; Ko, Shian-Chin; Chen, Chin-Ming; Weng, Shih-Feng; Tseng, Kuei-Ling; Cheng, Kuo-Chen

    2016-01-01

    Abstract This study investigated the outcomes and the prognostic factors among the very elderly (patients ≥80 years old) requiring prolonged mechanical ventilation (PMV). Between 2006 and 2014, all of the very elderly patients of age 80 or more transferred to respiratory care center (RCC) of a tertiary medical center were retrospectively identified, and only patients who used mechanical ventilation (MV) for >3 weeks were included in this study. A total of 510 very elderly patients undergoing PMV were identified. The mean age of the patients was 84.3 ± 3.3 years, and it ranged from 80 to 96 years. Male comprised most of the patients (n = 269, 52.7%), and most of the patients were transferred to RCC from medical ICU (n = 357, 70.0%). The APACHE II scores on RCC admission was 17.6 ± 6.0. At least 1 comorbidity was found in 419 (82.2%) patients. No significant differences of gender, disease severity, diagnosis, dialysis, laboratory examinations, comorbidities, and outcome were found between octogenarians (aged 80–89) and nonagenarians (aged ≥ 90). The overall in-hospital mortality rate was 21.8%. In the multivariate analysis, patients who had APACHE II score ≥ 15(odds ratio [OR], 2.30, 95% confidence interval [CI], 1.36–3.90), or albumin ≤ 2 g/dL (OR, 3.92, 95% CI, 2.17–7.01) were more likely to have significant in-hospital mortality (P < 0.05). The in-hospital mortality rate of the very elderly PMV patients in our RCC is 21.8%, and poor outcomes in this specific population were found to be associated with a higher APACHE II score and lower albumin level. PMID:26765452

  17. Mechanical Ventilation

    MedlinePlus

    ... or husband or next of kin). It is important that you talk with your family members and your doctors about using a ventilator and what you would like to happen in different situations. The more clearly you explain your values and choices to friends, loved ones and doctors, ...

  18. Tracheostomy in mechanical ventilation.

    PubMed

    Terragni, Pierpaolo; Faggiano, Chiara; Martin, Erica L; Ranieri, V Marco

    2014-08-01

    Airway access for mechanical ventilation (MV) can be provided either by orotracheal intubation (OTI) or tracheostomy tube. During episodes of acute respiratory failure, patients are commonly ventilated through an orotracheal tube that represents an easy and rapid initial placement of the airway device. OTI avoids acute surgical complications such as bleeding, nerve and posterior tracheal wall injury, and late complications such as wound infection and tracheal lumen stenosis that may emerge due to tracheostomy tube placement. Tracheostomy is often considered when MV is expected to be applied for prolonged periods or for the improvement of respiratory status, as this approach provides airway protection, facilitates access for secretion removal, improves patient comfort, and promotes progression of care in and outside the intensive care unit (ICU). The aim of this review is to assess the frequency and performance of different surgical or percutaneous dilational tracheostomy and timing and safety procedures associated with the use of fiberoptic bronchoscopy and ultrasounds. Moreover, we analyzed the performance based on National European surveys to assess the current tracheostomy practice in ICUs. PMID:25111644

  19. Effects of prolonged mechanical ventilation with a closed suction system on endotracheal tube resistance and its reversibility by a closed suction cleaning system.

    PubMed

    Adi, N A; Tomer, N T; Bergman, G B; Kishinevsky, E K; Wyncoll, D W

    2013-11-01

    The study objective was to evaluate endotracheal tubes (ETT) from extubated adult patients and compare them to new, unused, size-matched control tubes for changes in inspiratory resistance (Rinsp) and peak inspiratory pressure (PIP) before and immediately after suctioning with the Airway Medix Closed Suction System (AMCSS) (Biovo Technologies, 2013 Tel Aviv, Israel). Sixteen ETTs were recovered from predominantly medical patients who had required intubation and mechanical ventilation for more than 12 hours. ETTs were evaluated within 4.5 hours of extubation. Readings were taken during square wave flow, at rates of 40 and 60 l/minute. Cleaning of extubated ETTs using the AMCSS was able to restore them to almost original conditions in terms of Rinsp and PIP. The examined ETTs included tubes of various sizes ranging from internal diameter (ID) 7 to 8.5 mm and intubation periods ranging from 12 hours to 21 days. The mean Rinsp for the used and uncleaned ETTs was equivalent to 275% of the Rinsp of sized-matched new and unused ETTs. For 8 mm ID ETTs this was comparable to a measured Rinsp of a 5 mm tube. Following a single cleaning episode with the AMCSS, Rinsp decreased, regaining an effective ETT ID of a 7.5 to 8 mm tube. A single suctioning episode with this device resulted in a significant reduction in Rinsp, virtually restoring original flow variable values. The AMCSS represents a novel technology in closed suction systems, designed to achieve more effective inner lumen cleaning in prolonged mechanical ventilation. PMID:24180713

  20. Incidence, life expectancy and prognostic factors in cancer patients under prolonged mechanical ventilation: a nationwide analysis of 5,138 cases during 1998-2007

    PubMed Central

    2013-01-01

    Introduction This study is aimed at determining the incidence, survival rate, life expectancy, quality-adjusted life expectancy (QALE) and prognostic factors in patients with cancer in different organ systems undergoing prolonged mechanical ventilation (PMV). Methods We used data from the National Health Insurance Research Database of Taiwan from 1998 to 2007 and linked it with the National Mortality Registry to ascertain mortality. Subjects who received PMV, defined as having undergone mechanical ventilation continuously for longer than 21 days, were enrolled. The incidence of cancer patients requiring PMV was calculated, with the exception of patients with multiple cancers. The life expectancies and QALE of patients with different types of cancer were estimated. Quality-of-life data were taken from a sample of 142 patients who received PMV. A multivariable proportional hazards model was constructed to assess the effect of different prognostic factors, including age, gender, type of cancer, metastasis, comorbidities and hospital levels. Results Among 9,011 cancer patients receiving mechanical ventilation for more than 7 days, 5,138 undergoing PMV had a median survival of 1.37 months (interquartile range [IQR], 0.50 to 4.57) and a 1-yr survival rate of 14.3% (95% confidence interval [CI], 13.3% to 15.3%). The incidence of PMV was 10.4 per 100 ICU admissions. Head and neck cancer patients seemed to survive the longest. The overall life expectancy was 1.21 years, with estimated QALE ranging from 0.17 to 0.37 quality-adjusted life years for patients with poor and partial cognition, respectively. Cancer of liver (hazard ratio [HR], 1.55; 95% CI, 1.34 to 1.78), lung (HR, 1.45; 95% CI, 1.30 to 1.41) and metastasis (HR, 1.53; 95% CI, 1.42 to 1.65) were found to predict shorter survival independently. Conclusions Cancer patients requiring PMV had poor long-term outcomes. Palliative care should be considered early in these patients, especially when metastasis has occurred

  1. Sleep and Mechanical Ventilation in Critical Care.

    PubMed

    Blissitt, Patricia A

    2016-06-01

    Sleep disturbances in critically ill mechanically ventilated patients are common. Although many factors may potentially contribute to sleep loss in critical care, issues around mechanical ventilation are among the more complex. Sleep deprivation has systemic effects that may prolong the need for mechanical ventilation and length of stay in critical care and result in worse outcomes. This article provides a brief review of the physiology of sleep, physiologic changes in breathing associated with sleep, and the impact of mechanical ventilation on sleep. A summary of the issues regarding research studies to date is also included. Recommendations for the critical care nurse are provided. PMID:27215357

  2. Predicting reintubation, prolonged mechanical ventilation and death in post-coronary artery bypass graft surgery: a comparison between artificial neural networks and logistic regression models

    PubMed Central

    Mendes, Renata G.; de Souza, César R.; Machado, Maurício N.; Correa, Paulo R.; Di Thommazo-Luporini, Luciana; Arena, Ross; Myers, Jonathan; Pizzolato, Ednaldo B.

    2015-01-01

    Introduction In coronary artery bypass (CABG) surgery, the common complications are the need for reintubation, prolonged mechanical ventilation (PMV) and death. Thus, a reliable model for the prognostic evaluation of those particular outcomes is a worthwhile pursuit. The existence of such a system would lead to better resource planning, cost reductions and an increased ability to guide preventive strategies. The aim of this study was to compare different methods – logistic regression (LR) and artificial neural networks (ANNs) – in accomplishing this goal. Material and methods Subjects undergoing CABG (n = 1315) were divided into training (n = 1053) and validation (n = 262) groups. The set of independent variables consisted of age, gender, weight, height, body mass index, diabetes, creatinine level, cardiopulmonary bypass, presence of preserved ventricular function, moderate and severe ventricular dysfunction and total number of grafts. The PMV was also an input for the prediction of death. The ability of ANN to discriminate outcomes was assessed using receiver-operating characteristic (ROC) analysis and the results were compared using a multivariate LR. Results The ROC curve areas for LR and ANN models, respectively, were: for reintubation 0.62 (CI: 0.50–0.75) and 0.65 (CI: 0.53–0.77); for PMV 0.67 (CI: 0.57–0.78) and 0.72 (CI: 0.64–0.81); and for death 0.86 (CI: 0.79–0.93) and 0.85 (CI: 0.80–0.91). No differences were observed between models. Conclusions The ANN has similar discriminating power in predicting reintubation, PMV and death outcomes. Thus, both models may be applicable as a predictor for these outcomes in subjects undergoing CABG. PMID:26322087

  3. Clinical challenges in mechanical ventilation.

    PubMed

    Goligher, Ewan C; Ferguson, Niall D; Brochard, Laurent J

    2016-04-30

    Mechanical ventilation supports gas exchange and alleviates the work of breathing when the respiratory muscles are overwhelmed by an acute pulmonary or systemic insult. Although mechanical ventilation is not generally considered a treatment for acute respiratory failure per se, ventilator management warrants close attention because inappropriate ventilation can result in injury to the lungs or respiratory muscles and worsen morbidity and mortality. Key clinical challenges include averting intubation in patients with respiratory failure with non-invasive techniques for respiratory support; delivering lung-protective ventilation to prevent ventilator-induced lung injury; maintaining adequate gas exchange in severely hypoxaemic patients; avoiding the development of ventilator-induced diaphragm dysfunction; and diagnosing and treating the many pathophysiological mechanisms that impair liberation from mechanical ventilation. Personalisation of mechanical ventilation based on individual physiological characteristics and responses to therapy can further improve outcomes. PMID:27203509

  4. Early intervention of patients at risk for acute respiratory failure and prolonged mechanical ventilation with a checklist aimed at the prevention of organ failure: protocol for a pragmatic stepped-wedged cluster trial of PROOFCheck

    PubMed Central

    Gong, M N; Schenk, L; Gajic, O; Mirhaji, P; Sloan, J; Dong, Y; Festic, E; Herasevich, V

    2016-01-01

    Introduction Acute respiratory failure (ARF) often presents and progresses outside of the intensive care unit. However, recognition and treatment of acute critical illness is often delayed with inconsistent adherence to evidence-based care known to decrease the duration of mechanical ventilation (MV) and complications of critical illness. The goal of this trial is to determine whether the implementation of an electronic medical record-based early alert for progressive respiratory failure coupled with a checklist to promote early compliance to best practice in respiratory failure can improve the outcomes of patients at risk for prolonged respiratory failure and death. Methods and analysis A pragmatic stepped-wedged cluster clinical trial involving 6 hospitals is planned. The study will include adult hospitalised patients identified as high risk for MV >48 hours or death because they were mechanically ventilated outside of the operating room or they were identified as high risk for ARF on the Accurate Prediction of PROlonged VEntilation (APPROVE) score. Patients with advanced directives limiting intubation will be excluded. The intervention will consist of (1) automated identification and notification of clinician of high-risk patients by APPROVE or by invasive MV and (2) checklist of evidence-based practices in ARF (Prevention of Organ Failure Checklist—PROOFCheck). APPROVE and PROOFCheck will be developed in the pretrial period. Primary outcome is hospital mortality. Secondary outcomes include length of stay, ventilator and organ failure-free days and 6-month and 12-month mortality. Predefined subgroup analysis of patients with limitation of aggressive care after study entry is planned. Generalised estimating equations will be used to compare patients in the intervention phase with the control phase, adjusting for clustering within hospitals and time. Ethics and dissemination The study was approved by the institutional review boards. Results will be published

  5. Inhalation therapy in mechanical ventilation

    PubMed Central

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

    2015-01-01

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

  6. Anxiety and Agitation in Mechanically Ventilated Patients

    PubMed Central

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

    2013-01-01

    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. PMID:21908706

  7. Mechanical ventilation for severe asthma.

    PubMed

    Leatherman, James

    2015-06-01

    Acute exacerbations of asthma can lead to respiratory failure requiring ventilatory assistance. Noninvasive ventilation may prevent the need for endotracheal intubation in selected patients. For patients who are intubated and undergo mechanical ventilation, a strategy that prioritizes avoidance of ventilator-related complications over correction of hypercapnia was first proposed 30 years ago and has become the preferred approach. Excessive pulmonary hyperinflation is a major cause of hypotension and barotrauma. An appreciation of the key determinants of hyperinflation is essential to rational ventilator management. Standard therapy for patients with asthma undergoing mechanical ventilation consists of inhaled bronchodilators, corticosteroids, and drugs used to facilitate controlled hypoventilation. Nonconventional interventions such as heliox, general anesthesia, bronchoscopy, and extracorporeal life support have also been advocated for patients with fulminant asthma but are rarely necessary. Immediate mortality for patients who are mechanically ventilated for acute severe asthma is very low and is often associated with out-of-hospital cardiorespiratory arrest before intubation. However, patients who have been intubated for severe asthma are at increased risk for death from subsequent exacerbations and must be managed accordingly in the outpatient setting. PMID:26033128

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

    PubMed

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

    2015-01-01

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

  9. Ventilator-associated lung injury during assisted mechanical ventilation.

    PubMed

    Saddy, Felipe; Sutherasan, Yuda; Rocco, Patricia R M; Pelosi, Paolo

    2014-08-01

    Assisted mechanical ventilation (MV) may be a favorable alternative to controlled MV at the early phase of acute respiratory distress syndrome (ARDS), since it requires less sedation, no paralysis and is associated with less hemodynamic deterioration, better distal organ perfusion, and lung protection, thus reducing the risk of ventilator-associated lung injury (VALI). In the present review, we discuss VALI in relation to assisted MV strategies, such as volume assist-control ventilation, pressure assist-control ventilation, pressure support ventilation (PSV), airway pressure release ventilation (APRV), APRV with PSV, proportional assist ventilation (PAV), noisy ventilation, and neurally adjusted ventilatory assistance (NAVA). In summary, we suggest that assisted MV can be used in ARDS patients in the following situations: (1) Pao(2)/Fio(2) >150 mm Hg and positive end-expiratory pressure ≥ 5 cm H(2)O and (2) with modalities of pressure-targeted and time-cycled breaths including more or less spontaneous or supported breaths (A-PCV [assisted pressure-controlled ventilation] or APRV). Furthermore, during assisted MV, the following parameters should be monitored: inspiratory drive, transpulmonary pressure, and tidal volume (6 mL/kg). Further studies are required to determine the impact of novel modalities of assisted ventilation such as PAV, noisy pressure support, and NAVA on VALI. PMID:25105820

  10. [Mechanical ventilation in chronic ventilatory insufficiency].

    PubMed

    Schucher, B; Magnussen, H

    2007-10-01

    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

  11. [Weaning from mechanical ventilation. Weaning categories and weaning concepts].

    PubMed

    Geiseler, J; Kelbel, C

    2016-04-01

    The international classification of three weaning categories (simple weaning, difficult weaning, prolonged weaning) has been modified in the German weaning guidelines: the group of prolonged weaning has been subclassified into weaning without noninvasive ventilation (NIV), weaning with NIV, if necessary with continuing NIV in the form of home mechanical ventilation, and weaning failure.Strategies to prevent prolonged weaning comprise daily interruption of sedation, daily screening of capability of spontaneous breathing by a spontaneous breathing trial (SBT) and early implementation of NIV instead of continuing invasive mechanical ventilation especially in hypercapnic patients. The comorbidity left heart failure plays a major role in weaning failure and need for re-intubation-in this case early diagnosis and if necessary modification of heart therapy are important.Specialised weaning-centres offer the option for successful weaning for about 50-60 % of patients declared as unweanable by usual intensive care units. A multimodal therapy concept with respiratory therapists, physiotherapists and speech therapy is necessary to reach this goal. In case of weaning failure a professional discharge management to invasive home mechanical ventilation is important. Competent care by physicians in the out-of-hospital area is restricted by the sectoral division of responsibility by the German health care system. Improvement in this area is urgently needed. PMID:27084181

  12. The basis and basics of mechanical ventilation.

    PubMed

    Bone, R C; Eubanks, D H

    1991-06-01

    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

  13. Tracheomegaly and tracheosephagial fistula following mechanical ventilation: A case report and review of the literature

    PubMed Central

    Kucuk, Canan; Arda, Kemal; Ata, Naim; Turkkani, Mustafa Hamidullah; Yildiz, Özgür Ömer

    2016-01-01

    Postintubation Tracheoesophageal fistula (TEF) is a rare complication. Acquired TEF most commonly occurred following prolonged mechanical ventilation with an endotracheal or tracheostomy tube, cuff-related tracheal injury, post-intubation injury. We present a case of both tracheomegaly and tracheosephagial fistula following mechanical ventilation for 15 days, in the light of the literature. PMID:27222792

  14. Echocardiography in a Patient on Mechanical Ventilation.

    PubMed

    Sachdeva, Ankush

    2015-07-01

    Cardiopulmonary interactions or effects of spontaneous and mechanical ventilation (MV) were first documented in the year 1733. Stephen Hales showed that the blood pressure of healthy individual fell during spontaneous inspiration and he later went on to discover the ventilator. A year later Kussmaul described pulsus paradoxus (inspiratory absence of radial pulse) in patients with tubercular pericarditis. Echocardiography can help to diagnose a wide variety of cardiovascular diseases and can guide therapeutic decisions in patients on mechanical ventilation. PMID:26731826

  15. New modes of assisted mechanical ventilation.

    PubMed

    Suarez-Sipmann, F

    2014-05-01

    Recent major advances in mechanical ventilation have resulted in new exciting modes of assisted ventilation. Compared to traditional ventilation modes such as assisted-controlled ventilation or pressure support ventilation, these new modes offer a number of physiological advantages derived from the improved patient control over the ventilator. By implementing advanced closed-loop control systems and using information on lung mechanics, respiratory muscle function and respiratory drive, these modes are specifically designed to improve patient-ventilator synchrony and reduce the work of breathing. Depending on their specific operational characteristics, these modes can assist spontaneous breathing efforts synchronically in time and magnitude, adapt to changing patient demands, implement automated weaning protocols, and introduce a more physiological variability in the breathing pattern. Clinicians have now the possibility to individualize and optimize ventilatory assistance during the complex transition from fully controlled to spontaneous assisted ventilation. The growing evidence of the physiological and clinical benefits of these new modes is favoring their progressive introduction into clinical practice. Future clinical trials should improve our understanding of these modes and help determine whether the claimed benefits result in better outcomes. PMID:24507472

  16. Mechanical ventilation and mobilization: comparison between genders.

    PubMed

    Daniel, Christiane Riedi; Alessandra de Matos, Carla; Barbosa de Meneses, Jessica; Bucoski, Suzane Chaves Machado; Fréz, Andersom Ricardo; Mora, Cintia Teixeira Rossato; Ruaro, João Afonso

    2015-04-01

    [Purpose] To investigate the impact of gender on mobilization and mechanical ventilation in hospitalized patients in an intensive care unit. [Subjects and Methods] A retrospective cross-sectional study was conducted of the medical records of 105 patients admitted to a general intensive care unit. The length of mechanical ventilation, length of intensive care unit stay, weaning, time to sitting out of bed, time to performing active exercises, and withdrawal of sedation exercises were evaluated in addition to the characteristics of individuals, reasons for admission and risk scores. [Results] Women had significantly lower values APACHE II scores, duration of mechanical ventilation, time to withdrawal of sedation and time to onset of active exercises. [Conclusion] Women have a better functional response when admitted to the intensive care unit, spending less time ventilated and performing active exercises earlier. PMID:25995558

  17. Weaning from mechanical ventilation: why are we still looking for alternative methods?

    PubMed

    Frutos-Vivar, F; Esteban, A

    2013-12-01

    Most patients who require mechanical ventilation for longer than 24 hours, and who improve the condition leading to the indication of ventilatory support, can be weaned after passing a first spontaneous breathing test. The challenge is to improve the weaning of patients who fail that first test. We have methods that can be referred to as traditional, such as the T-tube, pressure support or synchronized intermittent mandatory ventilation (SIMV). In recent years, however, new applications of usual techniques as noninvasive ventilation, new ventilation methods such as automatic tube compensation (ATC), mandatory minute ventilation (MMV), adaptive support ventilation or automatic weaning systems based on pressure support have been described. Their possible role in weaning from mechanical ventilation among patients with difficult or prolonged weaning remains to be established. PMID:23084120

  18. Pulmonary perfusion during anesthesia and mechanical ventilation.

    PubMed

    Hedenstierna, G

    2005-06-01

    Cardiac output and the pulmonary perfusion can be affected by anesthesia and by mechanical ventilation. The changes contribute to impeded oxygenation of the blood. The major determinant of perfusion distribution in the lung is the relation between alveolar and pulmonary capillary pressures. Perfusion increases down the lung, due to hydrostatic forces. Since atelectasis is located in dependent lung regions, perfusion of non-ventilated lung parenchyma is common, producing shunt of around 8-10% of cardiac output. In addition, non-gravitational inhomogeneity of perfusion, that can be greater than the gravitational inhomogeneity, adds to impeded oxygenation of blood. Essentially all anaesthetics exert some, although mild, cardiodepressant action with one exception, ketamine. Ketamine may also increase pulmonary artery pressure, whereas other agents have little effect on pulmonary vascular tone. Mechanical ventilation impedes venous return and pushes blood flow downwards to dependent lung regions, and the effect may be striking with higher levels of PEEP. During one-lung anesthesia, there is shunt blood flow both in the non-ventilated and the ventilated lung, and shunt can be much larger in the ventilated lung than thought of. Recruitment manoeuvres shall be directed to the ventilated lung and other physical and pharmacological measures can be taken to manipulate blood flow in one lung anesthesia. PMID:15886595

  19. Iatrogenic pneumothorax related to mechanical ventilation

    PubMed Central

    Hsu, Chien-Wei; Sun, Shu-Fen

    2014-01-01

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

  20. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  1. Mechanical Ventilation and ARDS in the ED

    PubMed Central

    Mohr, Nicholas M.; Miller, Christopher N.; Deitchman, Andrew R.; Castagno, Nicole; Hassebroek, Elizabeth C.; Dhedhi, Adam; Scott-Wittenborn, Nicholas; Grace, Edward; Lehew, Courtney; Kollef, Marin H.

    2015-01-01

    BACKGROUND: There are few data regarding mechanical ventilation and ARDS in the ED. This could be a vital arena for prevention and treatment. METHODS: This study was a multicenter, observational, prospective, cohort study aimed at analyzing ventilation practices in the ED. The primary outcome was the incidence of ARDS after admission. Multivariable logistic regression was used to determine the predictors of ARDS. RESULTS: We analyzed 219 patients receiving mechanical ventilation to assess ED ventilation practices. Median tidal volume was 7.6 mL/kg predicted body weight (PBW) (interquartile range, 6.9-8.9), with a range of 4.3 to 12.2 mL/kg PBW. Lung-protective ventilation was used in 122 patients (55.7%). The incidence of ARDS after admission from the ED was 14.7%, with a mean onset of 2.3 days. Progression to ARDS was associated with higher illness severity and intubation in the prehospital environment or transferring facility. Of the 15 patients with ARDS in the ED (6.8%), lung-protective ventilation was used in seven (46.7%). Patients who progressed to ARDS experienced greater duration in organ failure and ICU length of stay and higher mortality. CONCLUSIONS: Lung-protective ventilation is infrequent in patients receiving mechanical ventilation in the ED, regardless of ARDS status. Progression to ARDS is common after admission, occurs early, and worsens outcome. Patient- and treatment-related factors present in the ED are associated with ARDS. Given the limited treatment options for ARDS, and the early onset after admission from the ED, measures to prevent onset and to mitigate severity should be instituted in the ED. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT01628523; URL: www.clinicaltrials.gov PMID:25742126

  2. [The applied value of BiPAP mechanical ventilation via facial of nasal mask before or after ordinary mechanical ventilation].

    PubMed

    Chen, P

    1998-01-01

    To expore the applied value of BiPAP ventilator before or after regular ventilation, 44 patients who had indicators of regular mechanical ventilation and 4 patients who had difficulty of getting free from endotracheal intubation mechanical ventilation were ventilated with BiPAP ventilator via facial or nasal mask. The results showed that 13/44 patients had good responses and avoided receiving regular mechanical ventilation with endotracheal intubation or incision. BiPAP ventilation was also effective in patients who were dependent on regular mechanical ventilatin. PMID:10682574

  3. Postoperative Complications Leading to Death after Coagulum Pyelolithotomy in a Tetraplegic Patient: Can We Prevent Prolonged Ileus, Recurrent Intestinal Obstruction due to Adhesions Requiring Laparotomies, Chest Infection Warranting Tracheostomy, and Mechanical Ventilation?

    PubMed Central

    Vaidyanathan, Subramanian; Soni, Bakul; Singh, Gurpreet; Hughes, Peter

    2013-01-01

    A 22-year-old male sustained C-6 tetraplegia in 1992. In 1993, intravenous pyelography revealed normal kidneys. Suprapubic cystostomy was performed. He underwent open cystolithotomy in 2004 and 2008. In 2009, computed tomography revealed bilateral renal calculi. Coagulum pyelolithotomy of left kidney was performed. Pleura and peritoneum were opened. Peritoneum could not be closed. Following surgery, he developed pulmonary atelectasis; he required tracheostomy and mechanical ventilation. He did not tolerate nasogastric feeding. CT of abdomen revealed bilateral renal calculi and features of proximal small bowel obstruction. Laparotomy revealed small bowel obstruction due to dense inflammatory adhesions involving multiple small bowel loops which protruded through the defect in sigmoid mesocolon and fixed posteriorly over the area of previous intervention. All adhesions were divided. The wide defect in mesocolon was not closed. In 2010, this patient again developed vomiting and distension of abdomen. Laparotomy revealed multiple adhesions. He developed chest infection and required ventilatory support again. He developed pressure sores and depression. Later abdominal symptoms recurred. This patient's general condition deteriorated and he expired in 2011. Conclusion. Risk of postoperative complications could have been reduced if minimally invasive surgery had been performed instead of open surgery to remove stones from left kidney. Suprapubic cystostomy predisposed to repeated occurrence of stones in urinary bladder and kidneys. Spinal cord physicians should try to establish intermittent catheterisation regime in tetraplegic patients. PMID:23533931

  4. Flow measurement in mechanical ventilation: a review.

    PubMed

    Schena, Emiliano; Massaroni, Carlo; Saccomandi, Paola; Cecchini, Stefano

    2015-03-01

    Accurate monitoring of flow rate and volume exchanges is essential to minimize ventilator-induced lung injury. Mechanical ventilators employ flowmeters to estimate the amount of gases delivered to patients and use the flow signal as a feedback to adjust the desired amount of gas to be delivered. Since flowmeters play a crucial role in this field, they are required to fulfill strict criteria in terms of dynamic and static characteristics. Therefore, mechanical ventilators are equipped with only the following kinds of flowmeters: linear pneumotachographs, fixed and variable orifice meters, hot wire anemometers, and ultrasonic flowmeters. This paper provides an overview of these sensors. Their working principles are described together with their relevant advantages and disadvantages. Furthermore, the most promising emerging approaches for flowmeters design (i.e., fiber optic technology and three dimensional micro-fabrication) are briefly reviewed showing their potential for this application. PMID:25659299

  5. A Medical Student Workshop in Mechanical Ventilation.

    ERIC Educational Resources Information Center

    And Others; Kushins, Lawrence G.

    1980-01-01

    In order to teach applied respiratory physiology to medical students, the anesthesiology faculty at the University of Florida College of Medicine has designed and implemented a course that includes a laboratory workshop in mechanical ventilation of an animal model that allows students to apply and expand their knowledge. (JMD)

  6. A miniature mechanical ventilator for newborn mice.

    PubMed

    Kolandaivelu, K; Poon, C S

    1998-02-01

    Transgenic/knockout mice with pre-defined mutations have become increasingly popular in biomedical research as models of human diseases. In some instances, the resulting mutation may cause cardiorespiratory distress in the neonatal or adult animals and may necessitate resuscitation. Here we describe the design and testing of a miniature and versatile ventilator that can deliver varying ventilatory support modes, including conventional mechanical ventilation and high-frequency ventilation, to animals as small as the newborn mouse. With a double-piston body chamber design, the device circumvents the problem of air leakage and obviates the need for invasive procedures such as endotracheal intubation, which are particularly important in ventilating small animals. Preliminary tests on newborn mice as early as postnatal day O demonstrated satisfactory restoration of pulmonary ventilation and the prevention of respiratory failure in mutant mice that are prone to respiratory depression. This device may prove useful in the postnatal management of transgenic/knockout mice with genetically inflicted respiratory disorders. PMID:9475887

  7. Assessment of mechanical ventilation parameters on respiratory mechanics.

    PubMed

    Pidaparti, Ramana M; Koombua, Kittisak; Ward, Kevin R

    2012-01-01

    Better understanding of airway mechanics is very important in order to avoid lung injuries for patients undergoing mechanical ventilation for treatment of respiratory problems in intensive-care medicine, as well as pulmonary medicine. Mechanical ventilation depends on several parameters, all of which affect the patient outcome. As there are no systematic numerical investigations of the role of mechanical ventilation parameters on airway mechanics, the objective of this study was to investigate the role of mechanical ventilation parameters on airway mechanics using coupled fluid-solid computational analysis. For the airway geometry of 3 to 5 generations considered, the simulation results showed that airflow velocity increased with increasing airflow rate. Airway pressure increased with increasing airflow rate, tidal volume and positive end-expiratory pressure (PEEP). Airway displacement and airway strains increased with increasing airflow rate, tidal volume and PEEP form mechanical ventilation. Among various waveforms considered, sine waveform provided the highest airflow velocity and airway pressure while descending waveform provided the lowest airway pressure, airway displacement and airway strains. These results combined with optimization suggest that it is possible to obtain a set of mechanical ventilation strategies to avoid lung injuries in patients. PMID:22136584

  8. Leaky ryanodine receptors contribute to diaphragmatic weakness during mechanical ventilation.

    PubMed

    Matecki, Stefan; Dridi, Haikel; Jung, Boris; Saint, Nathalie; Reiken, Steven R; Scheuermann, Valérie; Mrozek, Ségolène; Santulli, Gaetano; Umanskaya, Alisa; Petrof, Basil J; Jaber, Samir; Marks, Andrew R; Lacampagne, Alain

    2016-08-01

    Ventilator-induced diaphragmatic dysfunction (VIDD) refers to the diaphragm muscle weakness that occurs following prolonged controlled mechanical ventilation (MV). The presence of VIDD impedes recovery from respiratory failure. However, the pathophysiological mechanisms accounting for VIDD are still not fully understood. Here, we show in human subjects and a mouse model of VIDD that MV is associated with rapid remodeling of the sarcoplasmic reticulum (SR) Ca(2+) release channel/ryanodine receptor (RyR1) in the diaphragm. The RyR1 macromolecular complex was oxidized, S-nitrosylated, Ser-2844 phosphorylated, and depleted of the stabilizing subunit calstabin1, following MV. These posttranslational modifications of RyR1 were mediated by both oxidative stress mediated by MV and stimulation of adrenergic signaling resulting from the anesthesia. We demonstrate in the murine model that such abnormal resting SR Ca(2+) leak resulted in reduced contractile function and muscle fiber atrophy for longer duration of MV. Treatment with β-adrenergic antagonists or with S107, a small molecule drug that stabilizes the RyR1-calstabin1 interaction, prevented VIDD. Diaphragmatic dysfunction is common in MV patients and is a major cause of failure to wean patients from ventilator support. This study provides the first evidence to our knowledge of RyR1 alterations as a proximal mechanism underlying VIDD (i.e., loss of function, muscle atrophy) and identifies RyR1 as a potential target for therapeutic intervention. PMID:27457930

  9. [Monitorization of respiratory mechanics in the ventilated patient].

    PubMed

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

    2014-01-01

    Monitoring during mechanical ventilation allows the measurement of different parameters of respiratory mechanics. Accurate interpretation of these data can be useful for characterizing the situation of the different components of the respiratory system, and for guiding ventilator settings. In this review, we describe the basic concepts of respiratory mechanics, their interpretation, and their potential use in fine-tuning mechanical ventilation. PMID:24199991

  10. Pitfalls of mechanical ventilation in Thailand.

    PubMed

    Bunburaphong, Thananchai

    2014-01-01

    Pitfalls in the respiratory care and mechanical ventilation for patients continue to prevail in intensive care unit (ICU) or in some hospital wards in Thailand. There are two reasons that explain this phenomenon. Firstly, there are no professional respiratory therapists in Thailand. Secondly, most caregivers do not possess the adequate knowledge and skills requiredfor respiratory care and for initiating, maintaining and weaning patients off mechanical ventilation. Physicians and nurses have to practice in respiratory care and mechanical ventilation without participating in adequate training during their undergraduate studies and postgraduate training. In reality, physicians pay almost no attention to respiratory care. They leave the respiratory toilet, ventilator changes and monitoring of the patients to nurses who have many other tasks to attend to. To solve this problem will require restructuring of the Thai healthcare system. The Parliament will need to pass a "Respiratory Therapy Profession Act" to certify "respiratory therapists " as a new, registered health profession. The Office of the Civil Service Commission has to take the responsibility for creating the job title and a job description for respiratory therapists. Academic institutes have to provide training courses in respiratory therapy and grant appropriate levels of diplomas or certificates in respiratory therapy. Did actics and clinical skills required for respiratory care have to be sufficiently integrated into the curricula for medical students as well as nursing students. Physicians and nurses need to master their skills and acquired appropriate knowledge in respiratory care and mechanical ventilation until we can assure the necessary number of registered or certified respiratory therapists here in Thailand to help avoid such pitfalls. PMID:24855857

  11. History of Mechanical Ventilation. From Vesalius to Ventilator-induced Lung Injury.

    PubMed

    Slutsky, Arthur S

    2015-05-15

    Mechanical ventilation is a life-saving therapy that catalyzed the development of modern intensive care units. The origins of modern mechanical ventilation can be traced back about five centuries to the seminal work of Andreas Vesalius. This article is a short history of mechanical ventilation, tracing its origins over the centuries to the present day. One of the great advances in ventilatory support over the past few decades has been the development of lung-protective ventilatory strategies, based on our understanding of the iatrogenic consequences of mechanical ventilation such as ventilator-induced lung injury. These strategies have markedly improved clinical outcomes in patients with respiratory failure. PMID:25844759

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

    PubMed

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

    2014-02-01

    Respiratory muscle dysfunction, particularly of the diaphragm, may play a key role in the pathophysiological mechanisms that lead to difficulty in weaning patients from mechanical ventilation. The limited mobility of critically ill patients, and of the diaphragm in particular when prolonged mechanical ventilation support is required, promotes the early onset of respiratory muscle dysfunction, but this can also be caused or exacerbated by other factors that are common in these patients, such as sepsis, malnutrition, advanced age, duration and type of ventilation, and use of certain medications, such as steroids and neuromuscular blocking agents. In this review we will study in depth this multicausal origin, in which a common mechanism is altered protein metabolism, according to the findings reported in various models. The understanding of this multicausality produced by the same pathophysiological mechanism could facilitate the management and monitoring of patients undergoing mechanical ventilation. PMID:23669061

  13. Emergency Department Treatment of the Mechanically Ventilated Patient.

    PubMed

    Spiegel, Rory; Mallemat, Haney

    2016-02-01

    Mechanical ventilation has a long and storied history, but until recently the process required little from the emergency physician. In the modern emergency department, critically ill patients spend a longer period under the care of the emergency physician, requiring a greater understanding of ventilator management. This article serves as an introduction to mechanical ventilation and a user-friendly bedside guide. PMID:26614242

  14. Volumetric capnography in the mechanically ventilated patient.

    PubMed

    Blanch, L; Romero, P V; Lucangelo, U

    2006-06-01

    Expiratory capnogram provides qualitative information on the waveform patterns associated with mechanical ventilation and quantitative estimation of expired CO2. Volumetric capnography simultaneously measures expired CO2 and tidal volume and allows identification of CO2 from 3 sequential lung compartments: apparatus and anatomic dead space, from progressive emptying of alveoli and alveolar gas. Lung heterogeneity creates regional differences in CO2 concentration and sequential emptying contributes to the rise of the alveolar plateau and to the steeper the expired CO2 slope. The concept of dead space accounts for those lung areas that are ventilated but not perfused. In patients with sudden pulmonary vascular occlusion due to pulmonary embolism, the resultant high V/Q mismatch produces an increase in alveolar dead space. Calculations derived from volumetric capnography are useful to suspect pulmonary embolism at the bedside. Alveolar dead space is large in acute lung injury and when the effect of positive end-expiratory pressure (PEEP) is to recruit collapsed lung units resulting in an improvement of oxygenation, alveolar dead space may decrease, whereas PEEP-induced overdistension tends to increase alveolar dead space. Finally, measurement of physiologic dead space and alveolar ejection volume at admission or the trend during the first 48 hours of mechanical ventilation might provide useful information on outcome of critically ill patients with acute lung injury or acute respiratory distress syndrome. PMID:16682932

  15. Collective fluid mechanics of honeybee nest ventilation

    NASA Astrophysics Data System (ADS)

    Gravish, Nick; Combes, Stacey; Wood, Robert J.; Peters, Jacob

    2014-11-01

    Honeybees thermoregulate their brood in the warm summer months by collectively fanning their wings and creating air flow through the nest. During nest ventilation workers flap their wings in close proximity in which wings continuously operate in unsteady oncoming flows (i.e. the wake of neighboring worker bees) and near the ground. The fluid mechanics of this collective aerodynamic phenomena are unstudied and may play an important role in the physiology of colony life. We have performed field and laboratory observations of the nest ventilation wing kinematics and air flow generated by individuals and groups of honeybee workers. Inspired from these field observations we describe here a robotic model system to study collective flapping wing aerodynamics. We microfabricate arrays of 1.4 cm long flapping wings and observe the air flow generated by arrays of two or more fanning robotic wings. We vary phase, frequency, and separation distance among wings and find that net output flow is enhanced when wings operate at the appropriate phase-distance relationship to catch shed vortices from neighboring wings. These results suggest that by varying position within the fanning array honeybee workers may benefit from collective aerodynamic interactions during nest ventilation.

  16. Intraoperative mechanical ventilation strategies for one-lung ventilation.

    PubMed

    Şentürk, Mert; Slinger, Peter; Cohen, Edmond

    2015-09-01

    One-lung ventilation (OLV) has two major challenges: oxygenation and lung protection. The former is mainly because the ventilation of one lung is stopped while the perfusion continues; the latter is mainly because the whole ventilation is applied to only one lung. Recommendations for maintaining the oxygenation and methods of lung protection can contradict each other (such as high vs. low inspiratory oxygen fraction (FiO2), high vs. low tidal volume (TV), etc.). In light of the (very few) randomized clinical trials, this review focuses on a recent strategy for OLV, which includes a possible decrease in FiO2, lower TVs, positive end-expiratory pressure (PEEP) to the dependent lung, continuous positive airway pressure (CPAP) to the non-dependent lung and recruitment manoeuvres. Other applications such as anaesthetic choice and fluid management can affect the success of ventilatory strategy; new developments have changed the classical approach in this respect. PMID:26643100

  17. Drug-induced QT interval prolongation: mechanisms and clinical management

    PubMed Central

    Nachimuthu, Senthil; Assar, Manish D.

    2012-01-01

    The prolonged QT interval is both widely seen and associated with the potentially deadly rhythm, Torsades de Pointes (TdP). While it can occur spontaneously in the congenital form, there is a wide array of drugs that have been implicated in the prolongation of the QT interval. Some of these drugs have either been restricted or withdrawn from the market due to the increased incidence of fatal polymorphic ventricular tachycardia. The list of drugs that cause QT prolongation continues to grow, and an updated list of specific drugs that prolong the QT interval can be found at www.qtdrugs.org. This review focuses on the mechanism of drug-induced QT prolongation, risk factors for TdP, culprit drugs, prevention and monitoring of prolonged drug-induced QT prolongation and treatment strategies. PMID:25083239

  18. Newer nonconventional modes of mechanical ventilation.

    PubMed

    Singh, Preet Mohinder; Borle, Anuradha; Trikha, Anjan

    2014-07-01

    The conventional modes of ventilation suffer many limitations. Although they are popularly used and are well-understood, often they fail to match the patient-based requirements. Over the years, many small modifications in ventilators have been incorporated to improve patient outcome. The ventilators of newer generation respond to patient's demands by additional feedback systems. In this review, we discuss the popular newer modes of ventilation that have been accepted in to clinical practice. Various intensive care units over the world have found these modes to improve patient ventilator synchrony, decrease ventilator days and improve patient safety. The various modes discusses in this review are: Dual control modes (volume assured pressure support, volume support), Adaptive support ventilation, proportional assist ventilation, mandatory minute ventilation, Bi-level airway pressure release ventilation, (BiPAP), neurally adjusted ventilatory assist and NeoGanesh. Their working principles with their advantages and clinical limitations are discussed in brief. PMID:25114434

  19. Newer nonconventional modes of mechanical ventilation

    PubMed Central

    Singh, Preet Mohinder; Borle, Anuradha; Trikha, Anjan

    2014-01-01

    The conventional modes of ventilation suffer many limitations. Although they are popularly used and are well-understood, often they fail to match the patient-based requirements. Over the years, many small modifications in ventilators have been incorporated to improve patient outcome. The ventilators of newer generation respond to patient's demands by additional feedback systems. In this review, we discuss the popular newer modes of ventilation that have been accepted in to clinical practice. Various intensive care units over the world have found these modes to improve patient ventilator synchrony, decrease ventilator days and improve patient safety. The various modes discusses in this review are: Dual control modes (volume assured pressure support, volume support), Adaptive support ventilation, proportional assist ventilation, mandatory minute ventilation, Bi-level airway pressure release ventilation, (BiPAP), neurally adjusted ventilatory assist and NeoGanesh. Their working principles with their advantages and clinical limitations are discussed in brief. PMID:25114434

  20. Effects of mechanical ventilation on diaphragm function and biology.

    PubMed

    Gayan-Ramirez, G; Decramer, M

    2002-12-01

    The pathophysiological mechanisms of weaning from mechanical ventilation are not fully known, but there is accumulating evidence that mechanical ventilation induces inspiratory muscle dysfunction. Recently, several animal models have provided potential mechanisms for mechanical ventilation-induced effects on muscle function. In patients, weaning difficulties are associated with inspiratory muscle weakness and reduced endurance capacity. Animal studies demonstrated that diaphragm force was already decreased after 12 h of controlled mechanical ventilation and this worsened with time spent on the ventilator. Diaphragmatic myofibril damage observed after 3-days controlled mechanical ventilation was inversely correlated with maximal diaphragmatic force. Downregulation of the diaphragm insulin-like growth factor-I and MyoD/myogenin messenger ribonucleic acid occurred after 24 h and diaphragmatic oxidative stress and increased protease activity after 18 h. In keeping with these findings, diaphragm fibre atrophy was shown after 12 h and reduced diaphragm mass was reported after 48 h of controlled mechanical ventilation. These animal studies show that early alterations in diaphragm function develop after short-term mechanical ventilation. These alterations may contribute to the difficulties in weaning from mechanical ventilation seen in patients. Strategies to preserve respiratory muscle mass and function during mechanical ventilation should be developed. These may include: adaptation of medication, training of the diaphragm, stabilisation of the catabolic state and pharmacotherapy. PMID:12503720

  1. New strategies for mechanical ventilation. Lung protective ventilation.

    PubMed

    Wilmoth, D

    1999-12-01

    Although research is ongoing, and there are no definitive data to mandate the final answer to the question of which ventilation strategies result in the most optimal outcomes, the consensus of clinicians today suggests that we limit FIO2 to nontoxic levels, limit ventilating pressures and volumes, and use PEEP levels adequate to recruit alveoli and prevent tidal collapse. The critical care nurse must remain vigilant in his or her review of current literature to maintain knowledge of the current recommendations for optimal MV strategies. PMID:10855109

  2. Patient experiences during awake mechanical ventilation

    PubMed Central

    Prime, Danille; Arkless, Paul; Fine, Jonathan; Winter, Stephen; Wakefield, Dorothy B.; Scatena, Robyn

    2016-01-01

    Background Sedation practices in an ICU have shifted significantly in the past 20 years toward the use of minimizing sedation in mechanically ventilated patients. While minimizing sedation is clearly in the best interest of patients, data are lacking about how this approach affects patients’ experiences. Methods We interviewed mechanically ventilated patients receiving minimal sedation, over a 6-month period in an ICU, in order to explore their emotional, comfort, and communication experiences. Their responses were compared with the responses of their available family members regarding their attitudes and perceptions of the patients’ experiences. Results Seventy-five percent of the patients agreed or strongly agreed that they experienced pain, and 50% agreed or strongly agreed that they were comfortable. Half of the patients agreed or strongly agreed that they preferred to be kept awake. Five patients (31%) indicated that they were frustrated while 17 relatives (89%) agreed or strongly agreed that the patients were frustrated. When controlling for age and gender of respondents, family members perceived higher levels of patient pain (least square [LS] mean [95% CI]: 4.2 [3.7, 4.7] vs. 3.1 [2.5, 3.8]; p=0.022), frustration (LS mean [95% CI]: 4.2 [3.7, 4.6] vs. 3.2 [2.6, 3.9]; p=0.031), and adequate communication with nurses and doctors (LS mean [95% CI]: 3.9 [3.5, 4.4] vs. 3.1 [2.4, 3.7]; p=0.046) than the patients themselves. Conclusion Patients tolerated minimal sedation without significant frustration while mechanically ventilated despite experiencing discomfort. Patient and family member perceptions of the patient experience may differ, especially in regards to pain and frustration. The use of a communication tool can facilitate understanding of patient experiences and preferences. PMID:26908386

  3. Academic Emergency Medicine Physicians’ Knowledge of Mechanical Ventilation

    PubMed Central

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

    2016-01-01

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

  4. Ethical challenges in home mechanical ventilation: A secondary analysis

    PubMed Central

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

    2012-01-01

    The aim of this study was to explore the ethical challenges in home mechanical ventilation based on a secondary analysis of qualitative empirical data. The data included perceptions of healthcare professionals in hospitals and community health services and family members of children and adults using home mechanical ventilation. The findings show that a number of ethical challenges, or dilemmas, arise at all levels in the course of treatment: deciding who should be offered home mechanical ventilation, respect for patient and family wishes, quality of life, dignity and equal access to home mechanical ventilation. Other challenges were the impacts home mechanical ventilation had on the patient, the family, the healthcare services and the allocation of resources. A better and broader understanding of these issues is crucial in order to improve the quality of care for both patient and family and assist healthcare professionals involved in home mechanical ventilation to make decisions for the good of the patient and his or her family. PMID:22183963

  5. An Overview of the Predictor Standard Tools for Patient Weaning from Mechanical Ventilation

    PubMed Central

    Dehghani, Acieh; Abdeyazdan, Gholamhossein; Davaridolatabadi, Elham

    2016-01-01

    Most patients staying in the intensive care unit (ICU) require respiratory support through a ventilator. Since prolonged mechanical ventilation and weaning from the ventilator without criteria or at the inappropriate time can result in many complications, it is required that patients be weaned off the ventilator as soon as possible. This study was conducted to investigate a few standard tools that predict successful and timely weaning of patients from the ventilator. In the literature, SOFA and APACHE II scores, along with various tools, including Burn, Morganroth, and Corgian, have been used in weaning patients from the ventilator. In most of these studies, the increase or decrease in the APACHE II score was correlated with the patient’s weaning time, and this score could be used as a criterion for weaning. Several authors have expressed their belief that the SOFA score in the ICU is a good indicator of the prognosis of patient’s weaning from the ventilator, length of stay, mortality, and rate of recovery. Several studies have compared SOFA and APACHE II scores and have shown that there is a positive correlation between the SOFA and APACHE II scores and that both mortality and dependence on the ventilator are related to these two scores. Another tool is Burn’s weaning program. A higher Burn score indicates successful weaning off of the ventilator, successful extubation, lower length of mechanical ventilation, and shorter stay in the hospital. However, the capabilities of the Morganroth scale and the Gluck and Corgian scoring systems were evaluated only for successful weaning off of the ventilator, and a decrease in the Morganroth and Gluck scores indicated successful weaning. PMID:27054004

  6. An Overview of the Predictor Standard Tools for Patient Weaning from Mechanical Ventilation.

    PubMed

    Dehghani, Acieh; Abdeyazdan, Gholamhossein; Davaridolatabadi, Elham

    2016-02-01

    Most patients staying in the intensive care unit (ICU) require respiratory support through a ventilator. Since prolonged mechanical ventilation and weaning from the ventilator without criteria or at the inappropriate time can result in many complications, it is required that patients be weaned off the ventilator as soon as possible. This study was conducted to investigate a few standard tools that predict successful and timely weaning of patients from the ventilator. In the literature, SOFA and APACHE II scores, along with various tools, including Burn, Morganroth, and Corgian, have been used in weaning patients from the ventilator. In most of these studies, the increase or decrease in the APACHE II score was correlated with the patient's weaning time, and this score could be used as a criterion for weaning. Several authors have expressed their belief that the SOFA score in the ICU is a good indicator of the prognosis of patient's weaning from the ventilator, length of stay, mortality, and rate of recovery. Several studies have compared SOFA and APACHE II scores and have shown that there is a positive correlation between the SOFA and APACHE II scores and that both mortality and dependence on the ventilator are related to these two scores. Another tool is Burn's weaning program. A higher Burn score indicates successful weaning off of the ventilator, successful extubation, lower length of mechanical ventilation, and shorter stay in the hospital. However, the capabilities of the Morganroth scale and the Gluck and Corgian scoring systems were evaluated only for successful weaning off of the ventilator, and a decrease in the Morganroth and Gluck scores indicated successful weaning. PMID:27054004

  7. Exercise oscillatory ventilation: Mechanisms and prognostic significance

    PubMed Central

    Dhakal, Bishnu P; Lewis, Gregory D

    2016-01-01

    Alteration in breathing patterns characterized by cyclic variation of ventilation during rest and during exercise has been recognized in patients with advanced heart failure (HF) for nearly two centuries. Periodic breathing (PB) during exercise is known as exercise oscillatory ventilation (EOV) and is characterized by the periods of hyperpnea and hypopnea without interposed apnea. EOV is a non-invasive parameter detected during submaximal cardiopulmonary exercise testing. Presence of EOV during exercise in HF patients indicates significant impairment in resting and exercise hemodynamic parameters. EOV is also an independent risk factor for poor prognosis in HF patients both with reduced and preserved ejection fraction irrespective of other gas exchange variables. Circulatory delay, increased chemosensitivity, pulmonary congestion and increased ergoreflex signaling have been proposed as the mechanisms underlying the generation of EOV in HF patients. There is no proven treatment of EOV but its reversal has been noted with phosphodiesterase inhibitors, exercise training and acetazolamide in relatively small studies. In this review, we discuss the mechanistic basis of PB during exercise and the clinical implications of recognizing PB patterns in patients with HF. PMID:27022457

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

    PubMed Central

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

    2012-01-01

    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. PMID:23917935

  9. Forced oscillation assessment of respiratory mechanics in ventilated patients

    PubMed Central

    Navajas, Daniel; Farré, Ramon

    2001-01-01

    The forced oscillation technique (FOT) is a method for non-invasively assessing respiratory mechanics that is applicable both in paralysed and non-paralysed patients. As the FOT requires a minimal modification of the conventional ventilation setting and does not interfere with the ventilation protocol, the technique is potentially useful to monitor patient mechanics during invasive and noninvasive ventilation. FOT allows the assessment of the respiratory system linearity by measuring resistance and reactance at different lung volumes or end-expiratory pressures. Moreover, FOT allows the physician to track the changes in patient mechanics along the ventilation cycle. Applying FOT at different frequencies may allow the physician to interpret patient mechanics in terms of models with pathophysiological interest. The current methodological and technical experience make possible the implementation of portable and compact computerised FOT systems specifically addressed to its application in the mechanical ventilation setting. PMID:11178220

  10. The effect of mechanical ventilator settings during ventilator hyperinflation techniques: a bench-top analysis.

    PubMed

    Thomas, P J

    2015-01-01

    Ventilator hyperinflations are used by physiotherapists for the purpose of airway clearance in intensive care. There is limited data to guide the selection of mechanical ventilator modes and settings that may achieve desired flow patterns for ventilator hyperinflation. A mechanical ventilator was connected to two lung simulators and a respiratory mechanics monitor. Peak inspiratory (PIFR) and expiratory flow rates (PEFR) were measured during manipulation of ventilator modes (pressure support ventilation [PSV], volume-controlled synchronised intermittent mandatory ventilation [VC-SIMV] and pressure-controlled synchronised intermittent mandatory ventilation [PC-SIMV]) and ventilator settings (including set tidal volume, positive end-expiratory pressure, inspiratory flow rate, inspiratory pause, pressure support, inspiratory time and/or inflation pressure). Additionally, each trial was conducted with high (0.05 l/cmH2O) and low (0.01 l/cmH2O) compliance settings on the lung simulators. Each trial was dichotomised into success or failure under three categories (attainment of PIFR-PEFR less than or equal to 0.9, PEFR/PIFR greater than 17 l/min, PEFR greater than or equal to 40 l/min). A total of 232 trials were conducted (96 VC-SIMV, 96 PC-SIMV, 40 PSV). A greater proportion of VC-SIMV trials were ceased due to high peak inspiratory pressures (35%). However, VC-SIMV trials were more likely to be successful at meeting all three outcome measures (26 VC-SIMV trials, 7 PC-SIMV trials, 0 PSV trials). It was found that manipulation of settings in VC-SIMV mode appears more successful than PSV and PC-SIMV for ventilator hyperinflations. PMID:25579293

  11. Modern non-invasive mechanical ventilation turns 25.

    PubMed

    Díaz Lobato, Salvador; Mayoralas Alises, Sagrario

    2013-11-01

    The history of non-invasive mechanical ventilation goes back more than 100 years, but it was not until 1987 when what we could call "modern" non-invasive mechanical ventilation was developed. The description of Delaubier and Rideau of a patient with Duchenne's disease who had been effectively ventilated through a nasal mask marked the start of a new era in the history of non-invasive mechanical ventilation. Over these last 25years, we have witnessed exponential growth in its use, field of activity and technological advances on an exciting fast-paced track. We believe that it is time to review the main milestones that have marked the development of non-invasive mechanical ventilation to date, while paying homage to this therapeutic method that has contributed so much to the advancement of respiratory medicine in the last 25years. PMID:23347549

  12. Aerosol delivery of antimicrobial agents during mechanical ventilation: current practice and perspectives.

    PubMed

    Michalopoulos, Argyris; Metaxas, Eugenios I; Falagas, Matthew E

    2011-03-01

    Critically ill patients, who develop ventilator-associated pneumonia during prolonged mechanical ventilation, often require antimicrobial agents administered through the endotracheal or the tracheotomy tube. The delivery of antibiotics via the respiratory tract has been established over the past years as an alternative route in order to deliver high concentrations of antimicrobial agents directly to the lungs and avoid systemic toxicity. Since the only formal indications for inhaled/aerosolized antimicrobial agents is for patients suffering from cystic fibrosis, consequently the majority of research and published studies concerns this group of patients. Newer devices and new antibiotic formulations are currently off-label used in ambulatory cystic fibrosis patients whereas similar data for the mechanically ventilated patients do not yet exist. PMID:21235473

  13. Spatial distribution of ventilation and perfusion: mechanisms and regulation.

    PubMed

    Glenny, Robb W; Robertson, H Thomas

    2011-01-01

    With increasing spatial resolution of regional ventilation and perfusion, it has become more apparent that ventilation and blood flow are quite heterogeneous in the lung. A number of mechanisms contribute to this regional variability, including hydrostatic gradients, pleural pressure gradients, lung compressibility, and the geometry of the airway and vascular trees. Despite this marked heterogeneity in both ventilation and perfusion, efficient gas exchange is possible through the close regional matching of the two. Passive mechanisms, such as the shared effect of gravity and the matched branching of vascular and airway trees, create efficient gas exchange through the strong correlation between ventilation and perfusion. Active mechanisms that match local ventilation and perfusion play little if no role in the normal healthy lung but are important under pathologic conditions. PMID:23737178

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

    ERIC Educational Resources Information Center

    Young, Jenny M.; And Others

    1994-01-01

    Interviewed 13 amyotrophic lateral sclerosis patients. All believed that they alone should make decision regarding use of mechanical ventilation. Factors they considered important were quality of life, severity of disability, availability of ventilation by means of nasal mask, possible admission to long-term care facility, ability to discontinue…

  15. Ammonia emissions from two mechanically ventilated UK livestock buildings

    NASA Astrophysics Data System (ADS)

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

    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.

  16. MECHANICAL VENTILATION FOR THE LUNG TRANSPLANT RECIPIENT

    PubMed Central

    Barnes, Lindsey; Reed, Robert M.; Parekh, Kalpaj R.; Bhama, Jay K.; Pena, Tahuanty; Rajagopal, Srinivasan; Schmidt, Gregory A.; Klesney-Tait, Julia A.; Eberlein, Michael

    2015-01-01

    Mechanical ventilation (MV) is an important aspect in the intraoperative and early postoperative management of lung transplant (LTx)-recipients. There are no randomized-controlled trials of LTx-recipient MV strategies; however there are LTx center experiences and international survey studies reported. The main early complication of LTx is primary graft dysfunction (PGD), which is similar to the adult respiratory distress syndrome (ARDS). We aim to summarize information pertinent to LTx-MV, as well as PGD, ARDS, and intraoperative MV and to synthesize these available data into recommendations. Based on the available evidence, we recommend lung-protective MV with low-tidal-volumes (≤6 mL/kg predicted body weight [PBW]) and positive end-expiratory pressure for the LTx-recipient. In our opinion, the MV strategy should be based on donor characteristics (donor PBW as a parameter of actual allograft size), rather than based on recipient characteristics; however this donor-characteristics-based protective MV is based on indirect evidence and requires validation in prospective clinical studies. PMID:26495241

  17. Personalizing mechanical ventilation for acute respiratory distress syndrome.

    PubMed

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

    2016-03-01

    Lung-protective ventilation with low tidal volumes remains the cornerstone for treating patient with acute respiratory distress syndrome (ARDS). Personalizing such an approach to each patient's unique physiology may improve outcomes further. Many factors should be considered when mechanically ventilating a critically ill patient with ARDS. Estimations of transpulmonary pressures as well as individual's hemodynamics and respiratory mechanics should influence PEEP decisions as well as response to therapy (recruitability). This summary will emphasize the potential role of personalized therapy in mechanical ventilation. PMID:27076966

  18. Variability in Mechanical Ventilation: What's All the Noise About?

    PubMed

    Naik, Bhiken I; Lynch, Carl; Durbin, Charles G

    2015-08-01

    Controlled mechanical ventilation is characterized by a fixed breathing frequency and tidal volume. Physiological and mathematical models have demonstrated the beneficial effects of varying tidal volume and/or inspiratory pressure during positive-pressure ventilation. The addition of noise (random changes) to a monotonous nonlinear biological system, such as the lung, induces stochastic resonance that contributes to the recruitment of collapsed alveoli and atelectatic lung segments. In this article, we review the mechanism of physiological pulmonary variability, the principles of noise and stochastic resonance, and the emerging understanding that there are beneficial effects of variability during mechanical ventilation. PMID:25691765

  19. Personalizing mechanical ventilation for acute respiratory distress syndrome

    PubMed Central

    Beitler, Jeremy R.; Malhotra, Atul

    2016-01-01

    Lung-protective ventilation with low tidal volumes remains the cornerstone for treating patient with acute respiratory distress syndrome (ARDS). Personalizing such an approach to each patient’s unique physiology may improve outcomes further. Many factors should be considered when mechanically ventilating a critically ill patient with ARDS. Estimations of transpulmonary pressures as well as individual’s hemodynamics and respiratory mechanics should influence PEEP decisions as well as response to therapy (recruitability). This summary will emphasize the potential role of personalized therapy in mechanical ventilation. PMID:27076966

  20. Pressure versus volume controlled modes in invasive mechanical ventilation.

    PubMed

    Garnero, A J; Abbona, H; Gordo-Vidal, F; Hermosa-Gelbard, C

    2013-05-01

    The first generation of mechanical ventilators were controlled and cycled by pressure. Unfortunately, they did not allow control of the delivered tidal volume under changes in the dynamics of the respiratory system. This led to a second generation of ventilators that allowed volume control, hence favoring the ventilatory strategy based on normalization of the arterial gases. Studies conducted in the 1980s which related lung injury to the high ventilator pressures utilized while treating acute respiratory distress syndrome patients renewed interest in pressure-controlled mechanical ventilation. In addition, new evidence became available, leading to the development of pulmonary protective strategies aiming at preventing the progression of ventilator-induced lung injury. This review provides a detailed description of the control of pressure or volume using certain ventilatory modes, and offers a general view of their advantages and disadvantages, based on the latest available evidence. PMID:23260264

  1. Mechanical ventilation interacts with endotoxemia to induce extrapulmonary organ dysfunction

    PubMed Central

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

    2006-01-01

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

  2. Mechanical ventilation causes airway distension with proinflammatory sequelae in mice.

    PubMed

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

    2014-07-01

    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-α and IL-1β. 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

  3. Heliox Improves Carbon Dioxide Removal during Lung Protective Mechanical Ventilation.

    PubMed

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

    2014-01-01

    Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2) diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical ventilation using low tidal volumes. Methods. This is an observational cohort substudy of a single arm intervention study. Twenty-four ICU patients were included, who were admitted after a cardiac arrest and mechanically ventilated for 3 hours with heliox (50% helium; 50% oxygen). A fixed protective ventilation protocol (6 mL/kg) was used, with prospective observation for changes in lung mechanics and gas exchange. Statistics was by Bonferroni post-hoc correction with statistical significance set at P < 0.017. Results. During heliox ventilation, respiratory rate decreased (25 ± 4 versus 23 ± 5 breaths min(-1), P = 0.010). Minute volume ventilation showed a trend to decrease compared to baseline (11.1 ± 1.9 versus 9.9 ± 2.1 L min(-1), P = 0.026), while reducing PaCO2 levels (5.0 ± 0.6 versus 4.5 ± 0.6 kPa, P = 0.011) and peak pressures (21.1 ± 3.3 versus 19.8 ± 3.2 cm H2O, P = 0.024). Conclusions. Heliox improved CO2 elimination while allowing reduced minute volume ventilation in adult patients during protective mechanical ventilation. PMID:25548660

  4. Heliox Improves Carbon Dioxide Removal during Lung Protective Mechanical Ventilation

    PubMed Central

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

    2014-01-01

    Introduction. Helium is a noble gas with low density and increased carbon dioxide (CO2) diffusion capacity. This allows lower driving pressures in mechanical ventilation and increased CO2 diffusion. We hypothesized that heliox facilitates ventilation in patients during lung-protective mechanical ventilation using low tidal volumes. Methods. This is an observational cohort substudy of a single arm intervention study. Twenty-four ICU patients were included, who were admitted after a cardiac arrest and mechanically ventilated for 3 hours with heliox (50% helium; 50% oxygen). A fixed protective ventilation protocol (6 mL/kg) was used, with prospective observation for changes in lung mechanics and gas exchange. Statistics was by Bonferroni post-hoc correction with statistical significance set at P < 0.017. Results. During heliox ventilation, respiratory rate decreased (25 ± 4 versus 23 ± 5 breaths min−1, P = 0.010). Minute volume ventilation showed a trend to decrease compared to baseline (11.1 ± 1.9 versus 9.9 ± 2.1 L min−1, P = 0.026), while reducing PaCO2 levels (5.0 ± 0.6 versus 4.5 ± 0.6 kPa, P = 0.011) and peak pressures (21.1 ± 3.3 versus 19.8 ± 3.2 cm H2O, P = 0.024). Conclusions. Heliox improved CO2 elimination while allowing reduced minute volume ventilation in adult patients during protective mechanical ventilation. PMID:25548660

  5. Exposure to mechanical ventilation promotes tolerance to ventilator-induced lung injury by Ccl3 downregulation.

    PubMed

    Blázquez-Prieto, Jorge; López-Alonso, Inés; Amado-Rodríguez, Laura; Batalla-Solís, Estefanía; González-López, Adrián; Albaiceta, Guillermo M

    2015-10-15

    Inflammation plays a key role in the development of ventilator-induced lung injury (VILI). Preconditioning with a previous exposure can damp the subsequent inflammatory response. Our objectives were to demonstrate that tolerance to VILI can be induced by previous low-pressure ventilation, and to identify the molecular mechanisms responsible for this phenomenon. Intact 8- to 12-wk-old male CD1 mice were preconditioned with 90 min of noninjurious ventilation [peak pressure 17 cmH2O, positive end-expiratory pressure (PEEP) 2 cmH2O] and extubated. Seven days later, preconditioned mice and intact controls were submitted to injurious ventilation (peak pressure 20 cmH2O, PEEP 0 cmH2O) for 2 h to induce VILI. Preconditioned mice showed lower histological lung injury scores, bronchoalveolar lavage albumin content, and lung neutrophilic infiltration after injurious ventilation, with no differences in Il6 or Il10 expression. Microarray analyses revealed a downregulation of Calcb, Hspa1b, and Ccl3, three genes related to tolerance phenomena, in preconditioned animals. Among the previously identified genes, only Ccl3, which encodes the macrophage inflammatory protein 1 alpha (MIP-1α), showed significant differences between intact and preconditioned mice after high-pressure ventilation. In separate, nonconditioned animals, treatment with BX471, a specific blocker of CCR1 (the main receptor for MIP-1α), decreased lung damage and neutrophilic infiltration caused by high-pressure ventilation. We conclude that previous exposure to noninjurious ventilation induces a state of tolerance to VILI. Downregulation of the chemokine gene Ccl3 could be the mechanism responsible for this effect. PMID:26472813

  6. Systemic inflammation associated with mechanical ventilation among extremely preterm infants

    PubMed Central

    Bose, Carl L.; Laughon, Matthew M.; Allred, Elizabeth N.; O’Shea, T. Michael; Van Marter, Linda J.; Ehrenkranz, Richard A.; Fichorova, Raina N.; Leviton, Alan

    2012-01-01

    Little evidence is available to document that mechanical ventilation is an antecedent of systemic inflammation in preterm humans. We obtained blood on postnatal day 14 from 726 infants born before the 28th week of gestation and measured the concentrations of 25 inflammation-related proteins. We created multivariable models to assess the relationship between duration of ventilation and protein concentrations in the top quartile. Compared to newborns ventilated for fewer than 7 days (N=247), those ventilated for 14 days (N=330) were more likely to have elevated blood concentrations of pro-inflammatory cytokines (IL-1β, TNF-α), chemokines (IL-8, MCP-1), an adhesion molecule (ICAM-1), and a matrix metalloprotease (MMP-9), and less likely to have elevated blood concentrations of two chemokines (RANTES, MIP-1β), a matrix metalloproteinase (MMP-1), and a growth factor (VEGF). Newborns ventilated for 7-13 days (N=149) had systemic inflammation that approximated the pattern of newborns ventilated for 14 days. These relationships were not confounded by chorioamnionitis or antenatal corticosteroid exposure, and were not altered appreciably among infants with and without bacteremia. These findings suggest that two weeks of ventilation are more likely than shorter durations of ventilation to be accompanied by high blood concentrations of pro-inflammatory proteins indicative of systemic inflammation, and by low concentrations of proteins that might protect from inflammation-mediated organ injury. PMID:23148992

  7. Numerical investigation of pulmonary drug delivery under mechanical ventilation conditions

    NASA Astrophysics Data System (ADS)

    Banerjee, Arindam; van Rhein, Timothy

    2012-11-01

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

  8. Preemptive mechanical ventilation can block progressive acute lung injury

    PubMed Central

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

    2016-01-01

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

  9. Preemptive mechanical ventilation can block progressive acute lung injury.

    PubMed

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

    2016-02-01

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

  10. Mechanical ventilation reduces rat diaphragm blood flow and impairs O2 delivery and uptake

    PubMed Central

    Davis, Robert T.; Bruells, Christian S.; Stabley, John N.; McCullough, Danielle J.; Powers, Scott K.; Behnke, Bradley J.

    2012-01-01

    Objectives Although mechanical ventilation (MV) is a life-saving intervention in patients suffering from respiratory failure, prolonged MV is often associated with numerous complications including problematic weaning. In contracting skeletal muscle, inadequate O2 supply can limit oxidative phosphorylation resulting in muscular fatigue. However, whether prolonged MV results in decreased diaphragmatic blood and induces an O2 supply-demand imbalance in the diaphragm remains unknown. Design We tested the hypothesis that prolonged controlled MV results in a time-dependent reduction in rat diaphragmatic blood flow and microvascular PO2 and that prolonged MV would diminish the diaphragm’s ability to increase blood flow in response to muscular contractions. Measurements and Main Results Compared to 30 min of MV, 6 hrs of MV resulted in a 75% reduction in diaphragm blood flow (via radiolabeled microspheres), which did not occur in the intercostal muscle or high-oxidative hindlimb muscle (e.g., soleus). There was also a time-dependent decline in diaphragm microvascular PO2 (via phosphorescence quenching). Further, when contrasted to 30 min of MV, 6 hrs of MV significantly compromised the diaphragm’s ability to increase blood flow during electrically-induced contractions which resulted in a ~80% reduction in diaphragm O2 uptake. In contrast, 6 hrs of spontaneous breathing in anesthetized animals did not alter diaphragm blood flow or the ability to augment flow during electrically-induced contractions. Conclusions These new and important findings reveal that prolonged MV results in a time-dependent decrease in the ability of the diaphragm to augment blood flow to match O2 demand in response to contractile activity and could be a key contributing factor to difficult weaning. Although additional experiments are required to confirm, it is tempting to speculate that this ventilator-induced decline in diaphragmatic oxygenation could promote a hypoxia-induced generation of

  11. Clinical management of stressors perceived by patients on mechanical ventilation.

    PubMed

    Thomas, Loris A

    2003-02-01

    Psychological and psychosocial stressors perceived by the mechanically ventilated patient include intensive care unit environmental factors, communication factors, stressful symptoms, and the effectiveness of interventions. The studies reviewed in this article showed four stressors commonly identified by mechanically ventilated patients including dyspnea, anxiety, fear, and pain. Few interventional studies to reduce these stressors are available in the literature. Four interventions including hypnosis and relaxation, patient education and information sharing, music therapy, and supportive touch have been investigated in the literature and may be helpful in reducing patient stress. The advanced practice nurse is instrumental in the assessment of patient-perceived stressors while on the ventilator, and in the planning and implementation of appropriate interventions to reduce stressors and facilitate optimal ventilation, weaning, or both. PMID:12574705

  12. Airflow analysis in mechanically ventilated obstructed rooms

    NASA Astrophysics Data System (ADS)

    Priest, John Brian

    1999-11-01

    Local and mean air velocities and standard deviations were measured in realistic rooms. Obstructions represented occupants and equipment in the rooms, internal heat loads varied and supply air temperature differed from room averages. Experimental setups differed for the isothermal and nonisothermal tests. Room dimensions for isothermal tests were 2.44 m high by 4.88 x 4.88 m. Ten different obstruction ratios using three different inlet types were analyzed. Obstructions covered 0 to 30% floor area and from 0 to 75% of room height. Air was supplied at ventilation rates ranging between 0.8 and 1.1 m 3/s. Room dimensions for the nonisothermal tests were 2.44 m high by 3.66 x 7.32 m. Obstruction differences between solid versus open partitions for farrowing crates were investigated for three commercially available inlets using two ventilation loads. Ventilation rates were 0.11 to 1.18 m 3/s, simulating cold and warm weather ventilation conditions, respectively. Based on these data and theoretical calculations, a kinetic energy model that predicts average room air velocity and energy level was developed as a practical room air flow design and analysis tool. It was recommended that designers interested in using CFD as a tool should use a three dimensional laminar model for acceptable qualitative flow results. It was concluded that for typical room flowrates and inlet types the room air distribution system is obstruction ratio independent. Local velocities and standard deviations varied with each obstruction setup and inlet combination. However, average air velocities and turbulence intensities were not influenced by obstruction setups or inlet configurations. The decay rate of mean velocity kinetic energy in the bulk flow region was independent of obstructions and inlets. Room average kinetic energy was a function of the supplied kinetic energy within the supply jet plus internal kinetic energy resulting from internal heat load (convective energy).

  13. Clinical review: Respiratory mechanics in spontaneous and assisted ventilation

    PubMed Central

    Grinnan, Daniel C; Truwit, Jonathon Dean

    2005-01-01

    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 normal conditions and in disease states. As the severity of pulmonary disease increases, mechanical ventilation can become necessary. We discuss the use of pressure–volume curves in assisting with poorly compliant lungs while on mechanical ventilation. In addition, we discuss physiologic parameters that assist with ventilator weaning as the disease process abates. PMID:16277736

  14. Cardiac output estimation using pulmonary mechanics in mechanically ventilated patients

    PubMed Central

    2010-01-01

    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

  15. Cardiac output estimation using pulmonary mechanics in mechanically ventilated patients.

    PubMed

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

    2010-01-01

    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

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

    PubMed

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

    2013-12-01

    Hyperoxia inhibits pulmonary bioenergetics, causing delayed alveolarization in mice. We hypothesized that mechanical ventilation (MV) also causes a failure of bioenergetics to support alveolarization. To test this hypothesis, neonatal mice were ventilated with room air for 8 hours (prolonged) or for 2 hours (brief) with 15 μl/g (aggressive) tidal volume (Tv), or for 8 hours with 8 μl/g (gentle) Tv. After 24 hours or 10 days of recovery, lung mitochondria were examined for adenosine diphosphate (ADP)-phosphorylating respiration, using complex I (C-I)-dependent, complex II (C-II)-dependent, or cytochrome C oxidase (C-IV)-dependent substrates, ATP production rate, and the activity of C-I and C-II. A separate cohort of mice was exposed to 2,4-dinitrophenol (DNP), a known uncoupler of oxidative phosphorylation. At 10 days of recovery, pulmonary alveolarization and the expression of vascular endothelial growth factor (VEGF) were assessed. Sham-operated littermates were used as control mice. At 24 hours after aggressive MV, mitochondrial ATP production rates and the activity of C-I and C-II were significantly decreased compared with control mice. However, at 10 days of recovery, only mice exposed to prolonged-aggressive MV continued to exhibit significantly depressed mitochondrial respiration. This was associated with significantly poorer alveolarization and VEGF expression. In contrast, mice exposed to brief-aggressive or prolonged-gentle MV exhibited restored mitochondrial ADP-phosphorylation, normal alveolarization and pulmonary VEGF content. Exposure to DNP fully replicated the phenotype consistent with alveolar developmental arrest. Our data suggest that the failure of bioenergetics to support normal lung development caused by aggressive and prolonged ventilation should be considered a fundamental mechanism for the development of bronchopulmonary dysplasia in premature neonates. PMID:23980609

  17. Mitochondrial-targeted antioxidants protect against mechanical ventilation-induced diaphragm weakness

    PubMed Central

    Powers, Scott K.; Hudson, Matthew B.; Nelson, W. Bradley; Talbert, Erin E.; Min, Kisuk; Szeto, Hazel H.; Kavazis, Andreas N.; Smuder, Ashley J.

    2015-01-01

    BACKGROUND Mechanical ventilation (MV) is a life-saving intervention used to provide adequate pulmonary ventilation in patients suffering from respiratory failure. However, prolonged MV is associated with significant diaphragmatic weakness resulting from both myofiber atrophy and contractile dysfunction. Although several signaling pathways contribute to diaphragm weakness during MV, it is established that oxidative stress is required for diaphragmatic weakness to occur. Therefore, identifying the site(s) of MV-induced reactive oxygen species (ROS) production in the diaphragm is important. OBJECTIVE These experiments tested the hypothesis that elevated mitochondrial ROS emission is required for MV-induced oxidative stress, atrophy, and contractile dysfunction in the diaphragm. DESIGN Cause and effect was determined by preventing MV-induced mitochondrial ROS emission in the diaphragm of rats using a novel mitochondrial-targeted antioxidant (SS-31). MEASUREMENTS AND MAIN RESULTS Compared to mechanically ventilated animals treated with saline, animals treated with SS-31 were protected against MV-induced mitochondrial dysfunction, oxidative stress, and protease activation in the diaphragm. Importantly, treatment of animals with the mitochondrial antioxidant also protected the diaphragm against MV-induced myofiber atrophy and contractile dysfunction. CONCLUSIONS These results reveal that prevention of MV-induced increases in diaphragmatic mitochondrial ROS emission protects the diaphragm MV-induced diaphragmatic weakness. This important new finding indicates that mitochondria are a primary source of ROS production in the diaphragm during prolonged MV. These results could lead to the development of a therapeutic intervention to impede MV-induced diaphragmatic weakness. PMID:21460706

  18. Humidification during Mechanical Ventilation in the Adult Patient

    PubMed Central

    Al Ashry, Haitham S.; Modrykamien, Ariel M.

    2014-01-01

    Humidification of inhaled gases has been standard of care in mechanical ventilation for a long period of time. More than a century ago, a variety of reports described important airway damage by applying dry gases during artificial ventilation. Consequently, respiratory care providers have been utilizing external humidifiers to compensate for the lack of natural humidification mechanisms when the upper airway is bypassed. Particularly, active and passive humidification devices have rapidly evolved. Sophisticated systems composed of reservoirs, wires, heating devices, and other elements have become part of our usual armamentarium in the intensive care unit. Therefore, basic knowledge of the mechanisms of action of each of these devices, as well as their advantages and disadvantages, becomes a necessity for the respiratory care and intensive care practitioner. In this paper, we review current methods of airway humidification during invasive mechanical ventilation of adult patients. We describe a variety of devices and describe the eventual applications according to specific clinical conditions. PMID:25089275

  19. Weaning from mechanical ventilation in paediatrics. State of the art.

    PubMed

    Valenzuela, Jorge; Araneda, Patricio; Cruces, Pablo

    2014-03-01

    Weaning from mechanical ventilation is one of the greatest volume and strength issues in evidence-based medicine in critically ill adults. In these patients, weaning protocols and daily interruption of sedation have been implemented, reducing the duration of mechanical ventilation and associated morbidity. In paediatrics, the information reported is less consistent, so that as yet there are no reliable criteria for weaning and extubation in this patient group. Several indices have been developed to predict the outcome of weaning. However, these have failed to replace clinical judgement, although some additional measurements could facilitate this decision. PMID:23542044

  20. Brazilian recommendations of mechanical ventilation 2013. Part 2

    PubMed Central

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

    2014-01-01

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

  1. Brazilian recommendations of mechanical ventilation 2013. Part I

    PubMed Central

    2014-01-01

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

  2. Brazilian recommendations of mechanical ventilation 2013. Part I

    PubMed Central

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

    2014-01-01

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

  3. Brazilian recommendations of mechanical ventilation 2013. Part 2

    PubMed Central

    2014-01-01

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

  4. Home mechanical ventilation monitoring software: measure more or measure better?

    PubMed

    Luján, Manel; Sogo, Ana; Monsó, Eduard

    2012-05-01

    In recent years, there has been an increasing interest in knowing the consequences of the patient-ventilator interaction in non-invasive mechanical ventilation. Therefore, several ventilator manufacturers have incorporated into their devices the possibility to monitor ventilation on-line and download the data stored in their internal memories. However, there is not a consensus as to how these data should be presented, and said devices have still not been sufficiently validated to be used systematically in clinical practice. The objective of the present study is to develop a critical, argumentative analysis of the technical characteristics for determining the monitor variables used in the different software programs incorporated in commercial ventilators. Likewise, the study contemplates the presentation of the measurements on the screen display, emphasizing the advantages and defects of each one and analyzing their behavior in common clinical practice situations, such as changes in the interface or the presence of accidental leaks. In addition, solution mechanisms are proposed for establishing future directives for the parameters that are important for clinicians, as well as the manner for providing and interpreting said information. PMID:22206599

  5. Cost comparison of mechanically ventilated patients across the age span

    PubMed Central

    Hayman, William R.; Leuthner, Steven R.; Laventhal, Naomi T.; Brousseau, David; Lagatta, Joanne M.

    2016-01-01

    Objective to compare use of mechanical ventilation and hospital costs across ventilated patients of all ages, preterm through adults, in a nationally-representative sample. Study Design secondary analysis of the 2009 Agency for Healthcare Research and Quality National Inpatient Sample. Results 1,107,563 (2.8%) patients received mechanical ventilation. For surviving ventilated patients, median costs for infants ≤32 weeks’ gestation were $51,000–$209,000, whereas median costs for older patients were lower, from $17,000–$25,000. For non-surviving ventilated patients, median costs were $27,000–$39,000 except at the extremes of age; the median cost was $10,000 for <24 week newborns, and $14,000 for 91+ year adults. Newborns of all gestational ages had a disproportionate share of hospital costs relative to their total volume. Conclusions Most ICU resources at the extremes of age are not directed toward non-surviving patients. From a perinatal perspective, attention should be directed toward improving outcomes and reducing costs for all infants, not just at the earliest gestational ages. PMID:26468935

  6. Exhaled breath condensate collection in the mechanically ventilated patient.

    PubMed

    Carter, Stewart R; Davis, Christopher S; Kovacs, Elizabeth J

    2012-05-01

    Collection of exhaled breath condensate (EBC) is a non-invasive means of sampling the airway-lining fluid of the lungs. EBC contains numerous measurable mediators, whose analysis could change the management of patients with certain pulmonary diseases. While initially popularized in investigations involving spontaneously breathing patients, an increasing number of studies have been performed using EBC in association with mechanical ventilation. Collection of EBC in mechanically ventilated patients follows basic principles of condensation, but is influenced by multiple factors. Effective collection requires selection of a collection device, adequate minute ventilation, low cooling temperatures, and sampling times of greater than 10 min. Condensate can be contaminated by saliva, which needs to be filtered. Dilution of samples occurs secondary to distilled water in vapors and humidification in the ventilator circuit. Dilution factors may need to be employed when investigating non-volatile biomarkers. Storage and analysis should occur promptly at -70 °C to -80 °C to prevent rapid degradation of samples. The purpose of this review is to examine and describe methodologies and problems of EBC collection in mechanically ventilated patients. A straightforward and safe framework has been established to investigate disease processes in this population, yet technical aspects of EBC collection still exist that prevent clinical practicality of this technology. These include a lack of standardization of procedure and analysis of biomarkers, and of normal reference ranges for mediators in healthy individuals. Once these procedural aspects have been addressed, EBC could serve as a non-invasive alternative to invasive evaluation of lungs in mechanically ventilated patients. PMID:22398157

  7. Effect of the Prolonged Inspiratory to Expiratory Ratio on Oxygenation and Respiratory Mechanics During Surgical Procedures.

    PubMed

    Park, Jin Ha; Lee, Jong Seok; Lee, Jae Hoon; Shin, Seokyung; Min, Nar Hyun; Kim, Min-Soo

    2016-03-01

    Prolonged inspiratory to expiratory (I:E) ratio ventilation has been researched to reduce lung injury and improve oxygenation in surgical patients with one-lung ventilation (OLV) or carbon dioxide (CO2) pneumoperitoneum. We aimed to confirm the efficacy of the 1:1 equal ratio ventilation (ERV) compared with the 1:2 conventional ratio ventilation (CRV) during surgical procedures. Electronic databases, including PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar were searched.Prospective interventional trials that assessed the effects of prolonged I:E ratio of 1:1 during surgical procedures. Adult patients undergoing OLV or CO2 pneumoperitoneum as specific interventions depending on surgical procedures. The included studies were examined with the Cochrane Collaboration's tool. The data regarding intraoperative oxygenation and respiratory mechanics were extracted, and then pooled with standardized mean difference (SMD) using the method of Hedges. Seven trials (498 total patients, 274 with ERV) were included. From overall analysis, ERV did not improve oxygenation at 20 or 30 minutes after specific interventions (SMD 0.193, 95% confidence interval (CI): -0.094 to 0.481, P = 0.188). From subgroup analyses, ERV provided significantly improved oxygenation only with laparoscopy (SMD 0.425, 95% CI: 0.167-0.682, P = 0.001). At 60 minutes after the specific interventions, ERV improved oxygenation significantly in the overall analysis (SMD 0.447, 95% CI: 0.209-0.685, P < 0.001) as well as in the subgroup analyses with OLV (SMD 0.328, 95% CI: 0.011-0.644, P = 0.042) and laparoscopy (SMD 0.668, 95% CI: 0.052-1.285, P = 0.034). ERV provided lower peak airway pressure (Ppeak) and plateau airway pressure (Pplat) than CRV, regardless of the type of intervention. The relatively small number of the included articles and their heterogeneity could be the main limitations. ERV improved oxygenation at all of the

  8. Effect of the Prolonged Inspiratory to Expiratory Ratio on Oxygenation and Respiratory Mechanics During Surgical Procedures

    PubMed Central

    Park, Jin Ha; Lee, Jong Seok; Lee, Jae Hoon; Shin, Seokyung; Min, Nar Hyun; Kim, Min-Soo

    2016-01-01

    Abstract Prolonged inspiratory to expiratory (I:E) ratio ventilation has been researched to reduce lung injury and improve oxygenation in surgical patients with one-lung ventilation (OLV) or carbon dioxide (CO2) pneumoperitoneum. We aimed to confirm the efficacy of the 1:1 equal ratio ventilation (ERV) compared with the 1:2 conventional ratio ventilation (CRV) during surgical procedures. Electronic databases, including PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar were searched. Prospective interventional trials that assessed the effects of prolonged I:E ratio of 1:1 during surgical procedures. Adult patients undergoing OLV or CO2 pneumoperitoneum as specific interventions depending on surgical procedures. The included studies were examined with the Cochrane Collaboration's tool. The data regarding intraoperative oxygenation and respiratory mechanics were extracted, and then pooled with standardized mean difference (SMD) using the method of Hedges. Seven trials (498 total patients, 274 with ERV) were included. From overall analysis, ERV did not improve oxygenation at 20 or 30 minutes after specific interventions (SMD 0.193, 95% confidence interval (CI): −0.094 to 0.481, P = 0.188). From subgroup analyses, ERV provided significantly improved oxygenation only with laparoscopy (SMD 0.425, 95% CI: 0.167–0.682, P = 0.001). At 60 minutes after the specific interventions, ERV improved oxygenation significantly in the overall analysis (SMD 0.447, 95% CI: 0.209–0.685, P < 0.001) as well as in the subgroup analyses with OLV (SMD 0.328, 95% CI: 0.011–0.644, P = 0.042) and laparoscopy (SMD 0.668, 95% CI: 0.052–1.285, P = 0.034). ERV provided lower peak airway pressure (Ppeak) and plateau airway pressure (Pplat) than CRV, regardless of the type of intervention. The relatively small number of the included articles and their heterogeneity could be the main limitations. ERV improved oxygenation

  9. Lung hyperinflation by mechanical ventilation versus isolated tracheal aspiration in the bronchial hygiene of patients undergoing mechanical ventilation

    PubMed Central

    Assmann, Crisiela Brum; Vieira, Paulo José Cardoso; Kutchak, Fernanda; Rieder, Marcelo de Mello; Forgiarini, Soraia Genebra Ibrahim; Forgiarini Junior, Luiz Alberto

    2016-01-01

    Objective To determine the efficacy of lung hyperinflation maneuvers via a mechanical ventilator compared to isolated tracheal aspiration for removing secretions, normalizing hemodynamics and improving lung mechanics in patients on mechanical ventilation. Methods This was a randomized crossover clinical trial including patients admitted to the intensive care unit and on mechanical ventilation for more than 48 hours. Patients were randomized to receive either isolated tracheal aspiration (Control Group) or lung hyperinflation by mechanical ventilator (MVH Group). Hemodynamic and mechanical respiratory parameters were measured along with the amount of aspirated secretions. Results A total of 50 patients were included. The mean age of the patients was 44.7 ± 21.6 years, and 31 were male. Compared to the Control Group, the MVH Group showed greater aspirated secretion amount (3.9g versus 6.4g, p = 0.0001), variation in mean dynamic compliance (-1.3 ± 2.3 versus -2.9 ± 2.3; p = 0.008), and expired tidal volume (-0.7 ± 0.0 versus -54.1 ± 38.8, p = 0.0001) as well as a significant decrease in peak inspiratory pressure (0.2 ± 0.1 versus 2.5 ± 0.1; p = 0.001). Conclusion In the studied sample, the MVH technique led to a greater amount of aspirated secretions, significant increases in dynamic compliance and expired tidal volume and a significant reduction in peak inspiratory pressure. PMID:27096673

  10. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: Standards. 154.1205 Section 154.1205 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Area:...

  11. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Mechanical ventilation system: Standards. 154.1205 Section 154.1205 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction...

  12. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Mechanical ventilation system: Standards. 154.1205 Section 154.1205 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction...

  13. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Mechanical ventilation system: Standards. 154.1205 Section 154.1205 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction...

  14. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Mechanical ventilation system: Standards. 154.1205 Section 154.1205 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction...

  15. Computational tool for modeling and simulation of mechanically ventilated patients.

    PubMed

    Serna, Leidy Y; Hernandez, Alher M; Mananas, Miguel A

    2010-01-01

    The mechanical ventilator settings in patients with respiratory diseases like chronic obstructive pulmonary disease (COPD) during episodes of acute respiratory failure (ARF) is not a simple task that in most cases is successful based on the experience of physicians. This paper describes an interactive tool based in mathematical models, developed to make easier the study of the interaction between a mechanical ventilator and a patient. It describes all stages of system development, including simulated ventilatory modes, the pathologies of interest and interaction between the user and the system through a graphical interface developed in Matlab and Simulink. The developed computational tool allows the study of most widely used ventilatory modes and its advantages in the treatment of different kind of patients. The graphical interface displays all variables and parameters in the common way of last generation mechanical ventilators do and it is totally interactive, making possible its use by clinical personal, hiding the complexity of implemented mathematical models to the user. The evaluation in different clinical simulated scenes adjusts properly with recent findings in mechanical ventilation scientific literature. PMID:21096101

  16. Pulse oximetry performance in mechanically ventilated newborn infants.

    PubMed

    Solevåg, Anne L; Solberg, Marianne T; Šaltytė-Benth, Jūratė

    2015-08-01

    Pulse oximetry is widely used to target oxygenation in newborn infants. In a retrospective chart review of 138 mechanically ventilated infants, pulse oximetry overestimated blood oxygen saturation compared to arterial blood gas analyses. Despite improvements in pulse oximeter technology, pulse oximetry performance in sick newborns should still be under scrutiny. PMID:26067867

  17. Mechanical Ventilation as a Therapeutic Tool to Reduce ARDS Incidence.

    PubMed

    Nieman, Gary F; Gatto, Louis A; Bates, Jason H T; Habashi, Nader M

    2015-12-01

    Trauma, hemorrhagic shock, or sepsis can incite systemic inflammatory response syndrome, which can result in early acute lung injury (EALI). As EALI advances, improperly set mechanical ventilation (MV) can amplify early injury into a secondary ventilator-induced lung injury that invariably develops into overt ARDS. Once established, ARDS is refractory to most therapeutic strategies, which have not been able to lower ARDS mortality below the current unacceptably high 40%. Low tidal volume ventilation is one of the few treatments shown to have a moderate positive impact on ARDS survival, presumably by reducing ventilator-induced lung injury. Thus, there is a compelling case to be made that the focus of ARDS management should switch from treatment once this syndrome has become established to the application of preventative measures while patients are still in the EALI stage. Indeed, studies have shown that ARDS incidence is markedly reduced when conventional MV is applied preemptively using a combination of low tidal volume and positive end-expiratory pressure in both patients in the ICU and in surgical patients at high risk for developing ARDS. Furthermore, there is evidence from animal models and high-risk trauma patients that superior prevention of ARDS can be achieved using preemptive airway pressure release ventilation with a very brief duration of pressure release. Preventing rather than treating ARDS may be the way forward in dealing with this recalcitrant condition and would represent a paradigm shift in the way that MV is currently practiced. PMID:26135199

  18. Comparison of conventional mechanical ventilation and synchronous independent lung ventilation (SILV) in the treatment of unilateral lung injury.

    PubMed

    Hurst, J M; DeHaven, C B; Branson, R D

    1985-08-01

    Eight patients presenting with severe unilateral pulmonary injury responded poorly to conventional mechanical ventilation. Synchronous independent lung ventilation (SILV) was employed to provide support of ventilation and oxygenation without creating the ventilation/perfusion (V/Q) mismatch observed during conventional ventilation. All patients demonstrated improved oxygenation (mean increase, 80 torr) during SILV with the FIO2 unchanged from previous therapy. Invasive hemodynamic monitoring in five of eight patients showed no difference in the commonly measured cardiopulmonary parameters with the two forms of mechanical ventilation. Peak inspiratory pressure (PIP), continuous positive airway pressure (CPAP), and pressure change secondary to tidal volume delivery to the uninvolved lung were significantly less during SILV. SILV is an effective method of improving oxygenation in patients with severe unilateral pulmonary injury. PMID:3894680

  19. Mechanical ventilation of patients with acute lung injury.

    PubMed

    Sessler, C N

    1998-10-01

    Ventilatory management of patients with acute lung injury (ALI), particularly its most severe subset, acute respiratory distress syndrome (ARDS), is complex. Newer lung protective strategies emphasize measures to enhance alveolar recruitment and avoid alveolar overdistention, thus minimizing the risk of ventilator-induced lung injury (VILI). Key components of such strategies include the use of smaller-than-conventional tidal volumes which maintain peak transpulmonary pressure below the pressure associated with overdistention, and titration of positive end-expiratory pressure to promote maximal alveolar recruitment. Novel techniques, including prone positioning, inverse ratio ventilation, tracheal gas insufflation, and high frequency ventilation, are considerations in severe ARDS. No single approach is best for all patients; adjustment of ventilatory parameters to individual characteristics, such as lung mechanics and gas exchange, is required. PMID:9891634

  20. Automated mechanical ventilation: adapting decision making to different disease states.

    PubMed

    Lozano-Zahonero, S; Gottlieb, D; Haberthür, C; Guttmann, J; Möller, K

    2011-03-01

    The purpose of the present study is to introduce a novel methodology for adapting and upgrading decision-making strategies concerning mechanical ventilation with respect to different disease states into our fuzzy-based expert system, AUTOPILOT-BT. The special features are: (1) Extraction of clinical knowledge in analogy to the daily routine. (2) An automated process to obtain the required information and to create fuzzy sets. (3) The controller employs the derived fuzzy rules to achieve the desired ventilation status. For demonstration this study focuses exclusively on the control of arterial CO(2) partial pressure (p(a)CO(2)). Clinical knowledge from 61 anesthesiologists was acquired using a questionnaire from which different disease-specific fuzzy sets were generated to control p(a)CO(2). For both, patients with healthy lung and with acute respiratory distress syndrome (ARDS) the fuzzy sets show different shapes. The fuzzy set "normal", i.e., "target p(a)CO(2) area", ranges from 35 to 39 mmHg for healthy lungs and from 39 to 43 mmHg for ARDS lungs. With the new fuzzy sets our AUTOPILOT-BT reaches the target p(a)CO(2) within maximal three consecutive changes of ventilator settings. Thus, clinical knowledge can be extended, updated, and the resulting mechanical ventilation therapies can be individually adapted, analyzed, and evaluated. PMID:21069471

  1. Complementary home mechanical ventilation techniques. SEPAR Year 2014.

    PubMed

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

    2014-12-01

    This is a review of the different complementary techniques that are useful for optimizing home mechanical ventilation (HMV). Airway clearance is very important in patients with HMV and many patients, particularly those with reduced peak cough flow, require airway clearance (manual or assisted) or assisted cough techniques (manual or mechanical) and suctioning procedures, in addition to ventilation. In the case of invasive HMV, good tracheostomy cannula management is essential for success. HMV patients may have sleep disturbances that must be taken into account. Sleep studies including complete polysomnography or respiratory polygraphy are helpful for identifying patient-ventilator asynchrony. Other techniques, such as bronchoscopy or nutritional support, may be required in patients on HMV, particularly if percutaneous gastrostomy is required. Information on treatment efficacy can be obtained from HMV monitoring, using methods such as pulse oximetry, capnography or the internal programs of the ventilators themselves. Finally, the importance of the patient's subjective perception is reviewed, as this may potentially affect the success of the HMV. PMID:25138799

  2. Mechanical Ventilation Boot Camp: A Simulation-Based Pilot Study

    PubMed Central

    Yee, Jennifer; Fuenning, Charles; George, Richard; Hejal, Rana; Haines, Nhi; Dunn, Diane; Gothard, M. David; Ahmed, Rami A.

    2016-01-01

    Objectives. Management of mechanically ventilated patients may pose a challenge to novice residents, many of which may not have received formal dedicated critical care instruction prior to starting their residency training. There is a paucity of data regarding simulation and mechanical ventilation training in the medical education literature. The purpose of this study was to develop a curriculum to educate first-year residents on addressing and troubleshooting ventilator alarms. Methods. Prospective evaluation was conducted of seventeen residents undergoing a twelve-hour three-day curriculum. Residents were assessed using a predetermined critical action checklist for each case, as well as pre- and postcurriculum multiple-choice cognitive knowledge questionnaires and confidence surveys. Results. Significant improvements in cognitive knowledge, critical actions, and self-reported confidence were demonstrated. The mean change in test score from before to after intervention was +26.8%, and a median score increase of 25% was noted. The ARDS and the mucus plugging cases had statistically significant improvements in critical actions, p < 0.001. A mean increase in self-reported confidence was realized (1.55 to 3.64), p = 0.049. Conclusions. A three-day simulation curriculum for residents was effective in increasing competency, knowledge, and confidence with ventilator management. PMID:26949545

  3. Microbial profiling of dental plaque from mechanically ventilated patients.

    PubMed

    Sands, Kirsty M; Twigg, Joshua A; Lewis, Michael A O; Wise, Matt P; Marchesi, Julian R; Smith, Ann; Wilson, Melanie J; Williams, David W

    2016-02-01

    Micro-organisms isolated from the oral cavity may translocate to the lower airways during mechanical ventilation (MV) leading to ventilator-associated pneumonia (VAP). Changes within the dental plaque microbiome during MV have been documented previously, primarily using culture-based techniques. The aim of this study was to use community profiling by high throughput sequencing to comprehensively analyse suggested microbial changes within dental plaque during MV. Bacterial 16S rDNA gene sequences were obtained from 38 samples of dental plaque sampled from 13 mechanically ventilated patients and sequenced using the Illumina platform. Sequences were processed using Mothur, applying a 97 % gene similarity cut-off for bacterial species level identifications. A significant 'microbial shift' occurred in the microbial community of dental plaque during MV for nine out of 13 patients. Following extubation, or removal of the endotracheal tube that facilitates ventilation, sampling revealed a decrease in the relative abundance of potential respiratory pathogens and a compositional change towards a more predominantly (in terms of abundance) oral microbiota including Prevotella spp., and streptococci. The results highlight the need to better understand microbial shifts in the oral microbiome in the development of strategies to reduce VAP, and may have implications for the development of other forms of pneumonia such as community-acquired infection. PMID:26690690

  4. Ventilation distribution and chest wall mechanics in microgravity

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    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.

  5. [Lung-brain interaction in the mechanically ventilated patient].

    PubMed

    López-Aguilar, J; Fernández-Gonzalo, M S; Turon, M; Quílez, M E; Gómez-Simón, V; Jódar, M M; Blanch, L

    2013-10-01

    Patients with acute lung injury or acute respiratory distress syndrome (ARDS) admitted to the ICU present neuropsychological alterations, which in most cases extend beyond the acute phase and have an important adverse effect upon quality of life. The aim of this review is to deepen in the analysis of the complex interaction between lung and brain in critically ill patients subjected to mechanical ventilation. This update first describes the neuropsychological alterations occurring both during the acute phase of ICU stay and at discharge, followed by an analysis of lung-brain interactions during mechanical ventilation, and finally explores the etiology and mechanisms leading to the neurological disorders observed in these patients. The management of critical patients requires an integral approach focused on minimizing the deleterious effects over the short, middle or long term. PMID:23260265

  6. Histone Deacetylase Inhibitors Prolong Cardiac Repolarization through Transcriptional Mechanisms.

    PubMed

    Spence, Stan; Deurinck, Mark; Ju, Haisong; Traebert, Martin; McLean, LeeAnne; Marlowe, Jennifer; Emotte, Corinne; Tritto, Elaine; Tseng, Min; Shultz, Michael; Friedrichs, Gregory S

    2016-09-01

    Histone deacetylase (HDAC) inhibitors are an emerging class of anticancer agents that modify gene expression by altering the acetylation status of lysine residues of histone proteins, thereby inducing transcription, cell cycle arrest, differentiation, and cell death or apoptosis of cancer cells. In the clinical setting, treatment with HDAC inhibitors has been associated with delayed cardiac repolarization and in rare instances a lethal ventricular tachyarrhythmia known as torsades de pointes. The mechanism(s) of HDAC inhibitor-induced effects on cardiac repolarization is unknown. We demonstrate that administration of structurally diverse HDAC inhibitors to dogs causes delayed but persistent increases in the heart rate corrected QT interval (QTc), an in vivo measure of cardiac repolarization, at timepoints far removed from the Tmax for parent drug and metabolites. Transcriptional profiling of ventricular myocardium from dogs treated with various HDAC inhibitors demonstrated effects on genes involved in protein trafficking, scaffolding and insertion of various ion channels into the cell membrane as well as genes for specific ion channel subunits involved in cardiac repolarization. Extensive in vitro ion channel profiling of various structural classes of HDAC inhibitors (and their major metabolites) by binding and acute patch clamp assays failed to show any consistent correlations with direct ion channel blockade. Drug-induced rescue of an intracellular trafficking-deficient mutant potassium ion channel, hERG (G601S), and decreased maturation (glycosylation) of wild-type hERG expressed by CHO cells in vitro correlated with prolongation of QTc intervals observed in vivo The results suggest that HDAC inhibitor-induced prolongation of cardiac repolarization may be mediated in part by transcriptional changes of genes required for ion channel trafficking and localization to the sarcolemma. These data have broad implications for the development of these drug classes and

  7. Effect of PEEP on regional ventilation and perfusion in the mechanically ventilated preterm lamb

    SciTech Connect

    Schlessel, J.S.; Susskind, H.; Joel, D.D.; Bossuyt, A.; Harrold, W.H.; Zanzi, I.; Chanana, A.D. )

    1989-08-01

    Improvement of gas exchange through closer matching of regional ventilation (V) and lung perfusion (Q) with the application of positive end-expiratory pressure (PEEP) was evaluated in vivo in six mechanically ventilated preterm lambs (107-126 days/145 days gestation). Changes in V and Q were determined from in vivo scintigraphic measurements in four lung regions with inhaled radioactive 81mKr, and infused {sup 81m}Kr/dextrose and/or ({sup 99m}Tc)MAA as PEEP was applied at 2, 4, and 6 cm H{sub 2}O in each animal. Dynamic compliance varied between 0.02 and 0.40 ml/cm H{sub 2}O, which was consistent with surfactant deficiency. As PEEP was increased, the regional distribution of Q shifted from the rostral to the caudal lung regions (p less than 0.02 to less than 0.05), while that of V remained unchanged. Regional V/Q matching improved together with a trend towards improvement of arterial blood gases as PEEP was increased from 2 to 4 cm H{sub 2}O. Pulmonary scintigraphy offers a noninvasive methodology for the quantitative assessment of regional V and Q matching in preterm lambs and may be clinically applicable to ventilated neonates.

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

    PubMed Central

    2011-01-01

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

  9. 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

    Caprotta, Gustavo; Crotti, Patricia Gonzalez; Frydman, Judith

    2011-01-01

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

  10. NanoClusters Enhance Drug Delivery in Mechanical Ventilation

    NASA Astrophysics Data System (ADS)

    Pornputtapitak, Warangkana

    The overall goal of this thesis was to develop a dry powder delivery system for patients on mechanical ventilation. The studies were divided into two parts: the formulation development and the device design. The pulmonary system is an attractive route for drug delivery since the lungs have a large accessible surface area for treatment or drug absorption. For ventilated patients, inhaled drugs have to successfully navigate ventilator tubing and an endotracheal tube. Agglomerates of drug nanoparticles (also known as 'NanoClusters') are fine dry powder aerosols that were hypothesized to enable drug delivery through ventilator circuits. This Thesis systematically investigated formulations of NanoClusters and their aerosol performance in a conventional inhaler and a device designed for use during mechanical ventilation. These engineered powders of budesonide (NC-Bud) were delivered via a MonodoseRTM inhaler or a novel device through commercial endotracheal tubes, and analyzed by cascade impaction. NC-Bud had a higher efficiency of aerosol delivery compared to micronized stock budesonide. The delivery efficiency was independent of ventilator parameters such as inspiration patterns, inspiration volumes, and inspiration flow rates. A novel device designed to fit directly to the ventilator and endotracheal tubing connections and the MonodoseRTM inhaler showed the same efficiency of drug delivery. The new device combined with NanoCluster formulation technology, therefore, allowed convenient and efficient drug delivery through endotracheal tubes. Furthermore, itraconazole (ITZ), a triazole antifungal agent, was formulated as a NanoCluster powder via milling (top-down process) or precipitation (bottom-up process) without using any excipients. ITZ NanoClusters prepared by wet milling showed better aerosol performance compared to micronized stock ITZ and ITZ NanoClusters prepared by precipitation. ITZ NanoClusters prepared by precipitation methods also showed an amorphous state

  11. Patient Machine Interface for the Control of Mechanical Ventilation Devices

    PubMed Central

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

    2013-01-01

    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. PMID:24961620

  12. Postoperative Pulmonary Dysfunction and Mechanical Ventilation in Cardiac Surgery

    PubMed Central

    Badenes, Rafael; Lozano, Angels; Belda, F. Javier

    2015-01-01

    Postoperative pulmonary dysfunction (PPD) is a frequent and significant complication after cardiac surgery. It contributes to morbidity and mortality and increases hospitalization stay and its associated costs. Its pathogenesis is not clear but it seems to be related to the development of a systemic inflammatory response with a subsequent pulmonary inflammation. Many factors have been described to contribute to this inflammatory response, including surgical procedure with sternotomy incision, effects of general anesthesia, topical cooling, and extracorporeal circulation (ECC) and mechanical ventilation (VM). Protective ventilation strategies can reduce the incidence of atelectasis (which still remains one of the principal causes of PDD) and pulmonary infections in surgical patients. In this way, the open lung approach (OLA), a protective ventilation strategy, has demonstrated attenuating the inflammatory response and improving gas exchange parameters and postoperative pulmonary functions with a better residual functional capacity (FRC) when compared with a conventional ventilatory strategy. Additionally, maintaining low frequency ventilation during ECC was shown to decrease the incidence of PDD after cardiac surgery, preserving lung function. PMID:25705516

  13. Respiratory mechanics studied by forced oscillations during artificial ventilation.

    PubMed

    Peslin, R; Felicio da Silva, J; Duvivier, C; Chabot, F

    1993-06-01

    Potential advantages of the forced oscillation technique over other methods for monitoring total respiratory mechanics during artificial ventilation are that it does not require patient relaxation, and that additional information may be derived from the frequency dependence of the real (Re) and imaginary (Im) parts of respiratory impedance. We wanted to assess feasibility and usefulness of the forced oscillation technique in this setting and therefore used the approach in 17 intubated patients, mechanically ventilated for acute respiratory failure. Sinusoidal pressure oscillations at 5, 10 and 20 Hz were applied at the airway opening, using a specially devised loudspeaker-type generator placed in parallel with the ventilator. Real and imaginary parts were corrected for the flow-dependent impedance of the endotracheal tube; they usually exhibited large variations during the respiratory cycle, and were computed separately for the inspiratory and expiratory phases. In many instances the real part was larger during inspiration, probably due to the larger respiratory flow, and decreased with increasing frequency. The imaginary part of respiratory impedance usually increased with increasing frequency during expiration, as expected for a predominately elastic system, but often varied little, or even decreased, with increasing frequency during inspiration. In most patients, the data were inconsistent with the usual resistance-inertance-compliance model. A much better fit was obtained with a model featuring central airways and a peripheral pathway in parallel with bronchial compliance. The results obtained with the latter model suggest that dynamic airway compression occurred during passive expiration in a number of patients. We conclude that the use of forced oscillation is relatively easy to implement during mechanical ventilation, that it allows the study of respiratory mechanics at various points in the respiratory cycle, and may help in detecting expiratory flow

  14. Communicating While Receiving Mechanical Ventilation: Texting With a Smartphone.

    PubMed

    Shiber, Joseph; Thomas, Ayesha; Northcutt, Ashley

    2016-03-01

    Two young adults with severe facial injuries were receiving care in the trauma/surgical intensive care unit at a tertiary care, level I trauma center in the southeastern United States. Both patients were able to communicate by texting on their cellphones to family members, friends, and caregivers in the intensive care unit. Patients who are awake and already have experience texting with a smartphone or other electronic handheld device may be able to communicate well while receiving mechanical ventilation. PMID:26932926

  15. High-frequency oscillatory ventilation compared with conventional mechanical ventilation in the treatment of respiratory failure in preterm infants. The HIFI Study Group.

    PubMed

    1989-01-12

    We conducted a multicenter randomized clinical trial to compare the efficacy and safety of high-frequency ventilation with that of conventional mechanical ventilation in the treatment of respiratory failure in preterm infants. Of 673 preterm infants weighing between 750 and 2000 g, 346 were assigned to receive conventional mechanical ventilation and 327 to receive high-frequency oscillatory ventilation. The incidence of bronchopulmonary dysplasia was similar in the two groups (high-frequency ventilation, 40 percent; conventional mechanical ventilation, 41 percent; P = 0.79). High-frequency ventilation did not reduce mortality (18 percent, vs. 17 percent with conventional ventilation; P = 0.73) or the level of ventilatory support during the first 28 days. The crossover rate from high-frequency ventilation to conventional mechanical ventilation was greater than the crossover rate from mechanical to high-frequency ventilation (26 vs. 17 percent; P = 0.01). High-frequency ventilation, as compared with conventional mechanical ventilation, was associated with an increased incidence of pneumoperitoneum of pulmonary origin (3 vs. 1 percent; P = 0.05), grades 3 and 4 intracranial hemorrhage (26 vs. 18 percent; P = 0.02), and periventricular leukomalacia (12 vs. 7 percent; P = 0.05). These results suggest that high-frequency oscillatory ventilation, as used in this trial, does not offer any advantage over conventional mechanical ventilation in the treatment of respiratory failure in preterm infants, and it may be associated with undesirable side effects. PMID:2643039

  16. Hypervirulent Klebsiella pneumoniae induced ventilator-associated pneumonia in mechanically ventilated patients in China.

    PubMed

    Yan, Q; Zhou, M; Zou, M; Liu, W-e

    2016-03-01

    The purpose of this study was to investigate the clinical characteristics of hypervirulent K. pneumoniae (hvKP) induced ventilator-associated pneumonia (VAP) and the microbiological characteristics and epidemiology of the hvKP strains. A retrospective study of 49 mechanically ventilated patients with K. pneumoniae induced VAP was conducted at a university hospital in China from January 2014 to December 2014. Clinical characteristics and K. pneumoniae antimicrobial susceptibility and biofilm formation were analyzed. Genes of capsular serotypes K1, K2, K5, K20, K54 and K57 and virulence factors plasmid rmpA(p-rmpA), iroB, iucA, mrkD, entB, iutA, ybtS, kfu and allS were also evaluated. Multilocus sequence typing (MLST) and random amplified polymorphic DNA (RAPD) analyses were used to study the clonal relationship of the K. pneumoniae strains. Strains possessed p-rmpA and iroB and iucA were defined as hvKP. Of 49 patients, 14 patients (28.6 %) were infected by hvKP. Antimicrobial resistant rate was significantly higher in cKP than that in hvKP. One ST29 K54 extended-spectrum-beta-lactamase (ESBL) producing hvKP strain was detected. The prevalence of K1 and K2 in hvKP was 42.9 % and 21.4 %, respectively. The incidences of K1, K2, K20, p-rmpA, iroB, iucA, iutA, Kfu and alls were significantly higher in hvKP than those in cKP. ST23 was dominant among hvKP strains, and all the ST23 strains had identical RAPD pattern. hvKP has become a common pathogen of VAP in mechanically ventilated patients in China. Clinicians should increase awareness of hvKP induced VAP and enhance epidemiologic surveillance. PMID:26753990

  17. Recurrent Recruitment Manoeuvres Improve Lung Mechanics and Minimize Lung Injury during Mechanical Ventilation of Healthy Mice

    PubMed Central

    Reiss, Lucy Kathleen; Kowallik, Anke; Uhlig, Stefan

    2011-01-01

    Introduction Mechanical ventilation (MV) of mice is increasingly required in experimental studies, but the conditions that allow stable ventilation of mice over several hours have not yet been fully defined. In addition, most previous studies documented vital parameters and lung mechanics only incompletely. The aim of the present study was to establish experimental conditions that keep these parameters within their physiological range over a period of 6 h. For this purpose, we also examined the effects of frequent short recruitment manoeuvres (RM) in healthy mice. Methods Mice were ventilated at low tidal volume VT = 8 mL/kg or high tidal volume VT = 16 mL/kg and a positive end-expiratory pressure (PEEP) of 2 or 6 cmH2O. RM were performed every 5 min, 60 min or not at all. Lung mechanics were followed by the forced oscillation technique. Blood pressure (BP), electrocardiogram (ECG), heart frequency (HF), oxygen saturation and body temperature were monitored. Blood gases, neutrophil-recruitment, microvascular permeability and pro-inflammatory cytokines in bronchoalveolar lavage (BAL) and blood serum as well as histopathology of the lung were examined. Results MV with repetitive RM every 5 min resulted in stable respiratory mechanics. Ventilation without RM worsened lung mechanics due to alveolar collapse, leading to impaired gas exchange. HF and BP were affected by anaesthesia, but not by ventilation. Microvascular permeability was highest in atelectatic lungs, whereas neutrophil-recruitment and structural changes were strongest in lungs ventilated with high tidal volume. The cytokines IL-6 and KC, but neither TNF nor IP-10, were elevated in the BAL and serum of all ventilated mice and were reduced by recurrent RM. Lung mechanics, oxygenation and pulmonary inflammation were improved by increased PEEP. Conclusions Recurrent RM maintain lung mechanics in their physiological range during low tidal volume ventilation of healthy mice by preventing atelectasis and

  18. [Home mechanical ventilation-tracheostomy ventilation, for the long-term and variation].

    PubMed

    Yamamoto, Makoto

    2006-12-01

    We experienced long-term ventilation for 30 patients mostly with amyotrophic lateral sclerosis (ALS). For long-term ventilation by tracheostomy positive pressure ventilation (TPPV), we must set tidal volume (TV) over 600 ml, because setting 400 ml as TV usually applied in Japan, often develops atelectasis which causes frequent or serious pneumonia. To avoid both the elevation of airway pressure and hyper ventilation, the following intervals are needed: 10 times/min for breathing frequency and 2 seconds for exhaling time. In the cases with ventilator induced lung injury (VILI), it is necessary to lower the TV and to treat with steroid pulse therapy. In the transitional stage from non-invasive positive pressure ventilation (NPPV) to TPPV, we conduct tracheostomy for suction of the sputum. In that stage, by using a cuffless tracheal canule, we can continue NPPV. As another method in that stage, we recommend biphasic management by NPPV at daytime and TPPV at nighttime with a bi-level ventilator. This method can provide certain ventilation also during sleep. When the respiratory failure proceeds further, we manage the ventilation with a bi-level ventilator on TPPV, because a bi-level ventilator is also good adapting to assist spontaneous breathing in that stage. And if the patient does not have bulbar paralysis, the patient can utter by air leakage with using bi-level ventilator and flattening the cuff of the tracheal canule. PMID:17469348

  19. Transient-state mechanisms of wind-induced burrow ventilation.

    PubMed

    Turner, J Scott; Pinshow, Berry

    2015-01-15

    Burrows are common animal habitations, yet living in a burrow presents physiological challenges for its inhabitants because the burrow isolates them from sources and sinks for oxygen, carbon dioxide, water vapor and ammonia. Conventionally, the isolation is thought to be overcome by either diffusion gas exchange within the burrow or some means of capturing wind energy to power steady or quasi-steady bulk flows of air through it. Both are examples of what may be called 'DC' models, namely steady to quasi-steady flows powered by steady to quasi-steady winds. Natural winds, however, are neither steady nor quasi-steady, but are turbulent, with a considerable portion of the energy contained in so-called 'AC' (i.e. unsteady) components, where wind velocity varies chaotically and energy to power gas exchange is stored in some form. Existing DC models of burrow gas exchange do not account for this potentially significant source of energy for ventilation. We present evidence that at least two AC mechanisms operate to ventilate both single-opening burrows (of the Cape skink, Trachylepis capensis) and double-opening model burrows (of Sundevall's jird, Meriones crassus). We propose that consideration of the physiological ecology and evolution of the burrowing habit has been blinkered by the long neglect of AC ventilation. PMID:25609780

  20. Exhaled nitric oxide and carbon monoxide in mechanically ventilated brain-injured patients.

    PubMed

    Korovesi, I; Kotanidou, A; Papadomichelakis, E; Livaditi, O; Sotiropoulou, C; Koutsoukou, A; Marczin, N; Orfanos, S E

    2016-03-01

    The inflammatory influence and biological markers of prolonged mechanical-ventilation in uninjured human lungs remains controversial. We investigated exhaled nitric oxide (NO) and carbon monoxide (CO) in mechanically-ventilated, brain-injured patients in the absence of lung injury or sepsis at two different levels of positive end-expiratory pressure (PEEP). Exhaled NO and CO were assessed in 27 patients, without lung injury or sepsis, who were ventilated with 8 ml kg(-1) tidal volumes under zero end-expiratory pressure (ZEEP group, n  =  12) or 8 cm H2O PEEP (PEEP group, n  =  15). Exhaled NO and CO was analysed on days 1, 3 and 5 of mechanical ventilation and correlated with previously reported markers of inflammation and gas exchange. Exhaled NO was higher on day 3 and 5 in both patient groups compared to day 1: (PEEP group: 5.8 (4.4-9.7) versus 11.7 (6.9-13.9) versus 10.7 (5.6-16.6) ppb (p  <  0.05); ZEEP group: 5.3 (3.8-8.8) versus 9.8 (5.3-12.4) versus 9.6 (6.2-13.5) ppb NO peak levels for days 1, 3 and 5, respectively, p  <  0.05). Exhaled CO remained stable on day 3 but significantly decreased by day 5 in the ZEEP group only (6.3 (4.3-9.0) versus 8.1 (5.8-12.1) ppm CO peak levels for day 5 versus 1, p  <  0.05). The change scores for peak exhaled CO over day 1 and 5 showed significant correlations with arterial blood pH and plasma TNF levels (r s  =  0.49, p  =  0.02 and r s  =  -0.51 p  =  0.02, respectively). Exhaled NO correlated with blood pH in the ZEEP group and with plasma levels of IL-6 in the PEEP group. We observed differential changes in exhaled NO and CO in mechanically-ventilated patients even in the absence of manifest lung injury or sepsis. These may suggest subtle pulmonary inflammation and support application of real time breath analysis for molecular monitoring in critically ill patients. PMID:26934167

  1. Study on capacitance evolving mechanism of polypyrrole during prolonged cycling.

    PubMed

    Wang, JingPing; Xu, Youlong; Wang, Jie; Zhu, Jianbo; Bai, Yang; Xiong, Lilong

    2014-02-01

    A simple model on the evolution mechanism of PPy capacitance during prolonged cycling offers a reasonably description on the rapid increase and decay of PPy capacitance in 1 M 1-ethyl-3-methylimidazolium tetrafluoroborate/propylene carbonate (EtMeImBF4/PC). The capacitance of PPy films reached a very high specific capacitance of 420 F·g(-1) after 15 cycles when they worked in 1 M MeEt3ImBF4/PC. However, the capacitance rapidly decreased to 5% after only 400 cycles. The electronic conductivity and protonation level on the nitrogen site of PPy films rapidly decreased with the increase of cyclic number. The salt of EtMeImBF4 was monitored in PPy matrix by FTIR spectra after 400 cycles. The EQCM results indicated that a lot of 1-ethyl-3-methylimidazolium cations (EtMeIm(+)) were inserted during reduction process and retained in PPy matrix. The detained EtMeIm(+) cations bonded with doped p-toluenesulfonate anions (PTS(-)) in PPy matrix or BF4(-) anions from electrolyte and formed salts. Small amount of salts in PPy matrix can open more channels of ion insertion and resulted in a very high capacitance after 15 cycles. The continuous combination of detained EtMeIm(+) cations with doping anions of PTS(-) resulted in the rapid decrease of PPy protonation level on the nitrogen site and formation of compensate semiconductor state in PPy matrix. This should be responsible for the rapid decay of PPy conductivity and capacitance. The continuous accumulation of salts resulted in the great increase of PPy internal resistance. PMID:24428582

  2. Communication of mechanically ventilated patients in intensive care units

    PubMed Central

    Martinho, Carina Isabel Ferreira; Rodrigues, Inês Tello Rato Milheiras

    2016-01-01

    Objective The aim of this study was to translate and culturally and linguistically adapt the Ease of Communication Scale and to assess the level of communication difficulties for patients undergoing mechanical ventilation with orotracheal intubation, relating these difficulties to clinical and sociodemographic variables. Methods This study had three stages: (1) cultural and linguistic adaptation of the Ease of Communication Scale; (2) preliminary assessment of its psychometric properties; and (3) observational, descriptive-correlational and cross-sectional study, conducted from March to August 2015, based on the Ease of Communication Scale - after extubation answers and clinical and sociodemographic variables of 31 adult patients who were extubated, clinically stable and admitted to five Portuguese intensive care units. Results Expert analysis showed high agreement on content (100%) and relevance (75%). The pretest scores showed a high acceptability regarding the completion of the instrument and its usefulness. The Ease of Communication Scale showed excellent internal consistency (0.951 Cronbach's alpha). The factor analysis explained approximately 81% of the total variance with two scale components. On average, the patients considered the communication experiences during intubation to be "quite hard" (2.99). No significant correlation was observed between the communication difficulties reported and the studied sociodemographic and clinical variables, except for the clinical variable "number of hours after extubation" (p < 0.05). Conclusion This study translated and adapted the first assessment instrument of communication difficulties for mechanically ventilated patients in intensive care units into European Portuguese. The preliminary scale validation suggested high reliability. Patients undergoing mechanical ventilation reported that communication during intubation was "quite hard", and these communication difficulties apparently existed regardless of the

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

    PubMed Central

    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

    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

  4. Optimal Delivery of Aerosols to Infants During Mechanical Ventilation

    PubMed Central

    Azimi, Mandana; Hindle, Michael

    2014-01-01

    Abstract Purpose: The objective of this study was to determine optimal aerosol delivery conditions for a full-term (3.6 kg) infant receiving invasive mechanical ventilation by evaluating the effects of aerosol particle size, a new wye connector, and timing of aerosol delivery. Methods: In vitro experiments used a vibrating mesh nebulizer and evaluated drug deposition fraction and emitted dose through ventilation circuits containing either a commercial (CM) or new streamlined (SL) wye connector and 3-mm endotracheal tube (ETT) for aerosols with mass median aerodynamic diameters of 880 nm, 1.78 μm, and 4.9 μm. The aerosol was released into the circuit either over the full inhalation cycle (T1 delivery) or over the first half of inhalation (T2 delivery). Validated computational fluid dynamics (CFD) simulations and whole-lung model predictions were used to assess lung deposition and exhaled dose during cyclic ventilation. Results: In vitro experiments at a steady-state tracheal flow rate of 5 L/min resulted in 80–90% transmission of the 880-nm and 1.78-μm aerosols from the ETT. Based on CFD simulations with cyclic ventilation, the SL wye design reduced depositional losses in the wye by a factor of approximately 2–4 and improved lung delivery efficiencies by a factor of approximately 2 compared with the CM device. Delivery of the aerosol over the first half of the inspiratory cycle (T2) reduced exhaled dose from the ventilation circuit by a factor of 4 compared with T1 delivery. Optimal lung deposition was achieved with the SL wye connector and T2 delivery, resulting in 45% and 60% lung deposition for optimal polydisperse (∼1.78 μm) and monodisperse (∼2.5 μm) particle sizes, respectively. Conclusions: Optimization of selected factors and use of a new SL wye connector can substantially increase the lung delivery efficiency of medical aerosols to infants from current values of <1–10% to a range of 45–60%. PMID:24299500

  5. Brief mechanical ventilation impacts airway cartilage properties in neonatal lambs

    PubMed Central

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

    2012-01-01

    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. PMID:22170596

  6. Secretion movement during manual lung inflation and mechanical ventilation.

    PubMed

    Jones, Alice Y M

    2002-09-01

    This project aimed to investigate the direction of artificial sputum movement during mechanical ventilation (MV) and bagging (MH) using a tube model. Three solutions of artificial sputum (ultrasonic gel, viscosity 100, 200 and 300 poise (P)) were prepared. About 1 ml of gel was placed in a glass tube connected to a test lung at one end and, via a pneumotachograph, to either a mechanical ventilator or a self-inflating bag, at the other. The position of the gel in the tube was recorded before and after 20 artificial breaths. Simultaneous breath-to-breath respiratory mechanics were measured. The procedure was repeated three times for each gel viscosity, with a fresh experimental set up for each measurement. Results showed that the distance travelled from the lung was significantly greater with MH compared with MV (P < 0.001). The lower the gel viscosity, the further the gel moved from the lung with both ventilatory modes (P < 0.001). MH was superior to MV for secretion mobilisation in a tube model. PMID:12208090

  7. Impact of tongue biofilm removal on mechanically ventilated patients

    PubMed Central

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

    2013-01-01

    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 PMID:23887759

  8. Closure mechanisms of ventilated supercavities under steady and unsteady flows

    NASA Astrophysics Data System (ADS)

    Karn, Ashish; De, Rohan; Hong, Jiarong; Arndt, Roger E. A.

    2015-12-01

    The present work reports some interesting experimental results for ventilated supercavitation in steady and unsteady flows. First, a variety of closure modes obtained as a result of systematic variation in Froude number and air entrainment, are reported. The closure mechanisms were found to differ from the standard criterion reported in the literature. Further, the occurrence of a variety of stable and unstable closure mechanisms were discovered that have not been reported in the literature. Next, a hypothesis is presented to explain the cause behind these different closure mechanisms. The proposed hypothesis is then validated by synchronized high-speed imaging and pressure measurements inside and outside of the supercavity. These measurements show that the supercavity closure is a function of instantaneous cavitation number under unsteady flow conditions. (Research sponsored by Office of Naval Research, USA)

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

    PubMed

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

    2011-10-01

    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

  10. Critical Pertussis in a Young Infant Requiring Mechanical Ventilation

    PubMed Central

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

    2013-01-01

    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

  11. Automatic control of pressure support mechanical ventilation using fuzzy logic.

    PubMed

    Nemoto, T; Hatzakis, G E; Thorpe, C W; Olivenstein, R; Dial, S; Bates, J H

    1999-08-01

    There is currently no universally accepted approach to weaning patients from mechanical ventilation, but there is clearly a feeling within the medical community that it may be possible to formulate the weaning process algorithmically in some manner. Fuzzy logic seems suited this task because of the way it so naturally represents the subjective human notions employed in much of medical decision-making. The purpose of the present study was to develop a fuzzy logic algorithm for controlling pressure support ventilation in patients in the intensive care unit, utilizing measurements of heart rate, tidal volume, breathing frequency, and arterial oxygen saturation. In this report we describe the fuzzy logic algorithm, and demonstrate its use retrospectively in 13 patients with severe chronic obstructive pulmonary disease, by comparing the decisions made by the algorithm with what actually transpired. The fuzzy logic recommendations agreed with the status quo to within 2 cm H(2)O an average of 76% of the time, and to within 4 cm H(2)O an average of 88% of the time (although in most of these instances no medical decisions were taken as to whether or not to change the level of ventilatory support). We also compared the predictions of our algorithm with those cases in which changes in pressure support level were actually made by an attending physician, and found that the physicians tended to reduce the support level somewhat more aggressively than the algorithm did. We conclude that our fuzzy algorithm has the potential to control the level of pressure support ventilation from ongoing measurements of a patient's vital signs. PMID:10430727

  12. Update on clinical trials in home mechanical ventilation

    PubMed Central

    Hodgson, Luke E.

    2016-01-01

    Home mechanical ventilation (HMV) is an increasingly common intervention and is initiated for a range of pathological processes, including neuromuscular disease (NMD), chronic obstructive pulmonary disease (COPD) and obesity related respiratory failure. There have been important recent data published in this area, which helps to guide practice by indicating which populations may benefit from this intervention and the optimum method of setting up and controlling sleep disordered breathing. Recent superficially conflicting data has been published regarding HMV in COPD, with a trial in post-exacerbation patients suggesting no benefit, but in stable chronic hypercapnic patients suggesting a clear and sustained mortality benefit. The two studies are critiqued and the potential reasons for the differing results are discussed. Early and small trial data is frequently contradicted with larger randomised controlled trials and this has been the case with diaphragm pacing being shown to be potentially harmful in the latest data, confirming the importance of non-invasive ventilation (NIV) in NMD such as motor neurone disease. Advances in ventilator technology have so far appeared quicker than the clinical data to support their use; although small and often unblinded, the current data suggests equivalence to standard modes of NIV, but with potential comfort benefits that may enhance adherence. The indications for NIV have expanded since its inception, with an effort to treat sleep disordered breathing as a result of chronic heart failure (HF). The SERVE-HF trial has recently demonstrated no clear advantage to this technology and furthermore detected a potentially deleterious effect, with a worsening of all cause and cardiovascular mortality in the treated group compared to controls. The review serves to provide the reader with a critical review of recent advances in the field of sleep disordered breathing and HMV. PMID:26904266

  13. Update on clinical trials in home mechanical ventilation.

    PubMed

    Hodgson, Luke E; Murphy, Patrick B

    2016-02-01

    Home mechanical ventilation (HMV) is an increasingly common intervention and is initiated for a range of pathological processes, including neuromuscular disease (NMD), chronic obstructive pulmonary disease (COPD) and obesity related respiratory failure. There have been important recent data published in this area, which helps to guide practice by indicating which populations may benefit from this intervention and the optimum method of setting up and controlling sleep disordered breathing. Recent superficially conflicting data has been published regarding HMV in COPD, with a trial in post-exacerbation patients suggesting no benefit, but in stable chronic hypercapnic patients suggesting a clear and sustained mortality benefit. The two studies are critiqued and the potential reasons for the differing results are discussed. Early and small trial data is frequently contradicted with larger randomised controlled trials and this has been the case with diaphragm pacing being shown to be potentially harmful in the latest data, confirming the importance of non-invasive ventilation (NIV) in NMD such as motor neurone disease. Advances in ventilator technology have so far appeared quicker than the clinical data to support their use; although small and often unblinded, the current data suggests equivalence to standard modes of NIV, but with potential comfort benefits that may enhance adherence. The indications for NIV have expanded since its inception, with an effort to treat sleep disordered breathing as a result of chronic heart failure (HF). The SERVE-HF trial has recently demonstrated no clear advantage to this technology and furthermore detected a potentially deleterious effect, with a worsening of all cause and cardiovascular mortality in the treated group compared to controls. The review serves to provide the reader with a critical review of recent advances in the field of sleep disordered breathing and HMV. PMID:26904266

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

    PubMed Central

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

    2015-01-01

    Energy-efficient buildings need mechanical ventilation. However, there are concerns that inadequate mechanical ventilation may lead to impaired indoor air quality. Using a semi-experimental field study, we investigated if exposure of occupants of two types of buildings (mechanical vs. natural ventilation) differs with regard to indoor air pollutants and climate factors. We investigated living and bedrooms in 123 buildings (62 highly energy-efficient and 61 conventional buildings) built in the years 2010 to 2012 in Austria (mainly Vienna and Lower Austria). Measurements of indoor parameters (climate, chemical pollutants and biological contaminants) were conducted twice. In total, more than 3000 measurements were performed. Almost all indoor air quality and room climate parameters showed significantly better results in mechanically ventilated homes compared to those relying on ventilation from open windows and/or doors. This study does not support the hypothesis that occupants in mechanically ventilated low energy houses are exposed to lower indoor air quality. PMID:26561823

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

    PubMed Central

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

    2011-01-01

    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. PMID:21333174

  16. Development and implementation of explicit computerized protocols for mechanical ventilation in children

    PubMed Central

    2011-01-01

    Mechanical ventilation can be perceived as a treatment with a very narrow therapeutic window, i.e., highly efficient but with considerable side effects if not used properly and in a timely manner. Protocols and guidelines have been designed to make mechanical ventilation safer and protective for the lung. However, variable effects and low compliance with use of written protocols have been reported repeatedly. Use of explicit computerized protocols for mechanical ventilation might very soon become a "must." Several closed loop systems are already on the market, and preliminary studies are showing promising results in providing patients with good quality ventilation and eventually weaning them faster from the ventilator. The present paper defines explicit computerized protocols for mechanical ventilation, describes how these protocols are designed, and reports the ones that are available on the market for children. PMID:22189095

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

    PubMed

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

    2015-11-01

    Non-invasive mechanical ventilation is a method of ventilatory assistance aimed at increasing alveolar ventilation, thus achieving, in selected subjects, the avoidance of endotracheal intubation and invasive mechanical ventilation, with the consequent improvement in survival. There has been a systematic review and study of the technical, clinical experiences, and recommendations concerning the application of non-invasive mechanical ventilation in the pre- and intraoperative period. The use of prophylactic non-invasive mechanical ventilation before surgery that involves significant alterations in the ventilatory function may decrease the incidence of postoperative respiratory complications. Its intraoperative use will mainly depend on the type of surgery, type of anaesthetic technique, and the clinical status of the patient. Its use allows greater anaesthetic depth without deterioration of oxygenation and ventilation of patients. PMID:25702198

  18. Successful use of nasal BiPAP in three patients previously requiring intubation and mechanical ventilation.

    PubMed

    Poponick, J M; Renston, J P; Emerman, C L

    1997-01-01

    Noninvasive mask ventilation may be used to treat patients with impending respiratory failure. In this case series, three patients with severe chronic obstructive pulmonary disease, who required mechanical ventilation in the past, were successfully treated with nasal bi-level positive airway pressure (BiPAP). All patients tolerated BiPAP well without complications. Therefore, nasal BiPAP may be considered a treatment option for patients with severe COPD who have previously required intubation and mechanical ventilation. PMID:9404794

  19. Mechanical ventilation: past lessons and the near future.

    PubMed

    Marini, John J

    2013-01-01

    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

  20. Resolution of obstructive atelectasis with non-invasive mechanical ventilation.

    PubMed

    Mirambeaux Villalona, Rosa; Mayoralas Alises, Sagrario; Díaz Lobato, Salvador

    2014-10-01

    Bronchoscopy is a commonly used technique in patients with atelectasis due to mucus plugs. We present here the case of an 82-year-old patient with a history of Meige's syndrome who developed acute respiratory failure due to atelectasis of the right upper lobe associated with hospital-acquired pneumonia. The patient had a severely reduced level of consciousness, significant work-of-breathing and severe hypercapnic acidosis, all of which contraindicated bronchoscopy. Bi-level noninvasive mechanical ventilation (NIMV) was initiated by way of a face mask. Progress was favourable, with clear clinical and gasometric improvement. The chest X-ray performed 12hours later showed complete resolution of the atelectasis. These data suggest that NIMV may be useful in the treatment of atelectasis is some critical patients. PMID:24411928

  1. Outcome at school-age after neonatal mechanical ventilation.

    PubMed

    Gunn, T R; Lepore, E; Outerbridge, E W

    1983-06-01

    103 school-age children (5 to 12 years) who survived mechanical ventilation for neonatal respiratory failure were evaluated for growth, neurological, intellectual, psychological and school function in order to determine those children most at risk for handicap. A major handicap occurred in seven children, preventing attendance at normal school or normal classes. Neurological sequelae were significantly associated with perinatal asphyxia and with birthweights of 1500g or less, and neurological sequelae and socio-economic factors were the major determinants of ability. The effects of the Neonatal Intensive Care Unit (NICU) experience on parents and subsequent parent-child relationships were also investigated: 67 per cent of the mothers were very upset by the experience and many continue to worry excessively about the health of their child. Parents who visited their child in the NICU frequently were significantly more anxious and overprotective, restricting many activities even when the child was of school age. PMID:6873492

  2. The Extent of Ventilator-Induced Lung Injury in Mice Partly Depends on Duration of Mechanical Ventilation

    PubMed Central

    Hegeman, Maria A.; Hemmes, Sabrine N. T.; Kuipers, Maria T.; Bos, Lieuwe D. J.; Jongsma, Geartsje; Roelofs, Joris J. T. H.; van der Sluijs, Koenraad F.; Juffermans, Nicole P.; Vroom, Margreeth B.; Schultz, Marcus J.

    2013-01-01

    Background. Mechanical ventilation (MV) has the potential to initiate ventilator-induced lung injury (VILI). The pathogenesis of VILI has been primarily studied in animal models using more or less injurious ventilator settings. However, we speculate that duration of MV also influences severity and character of VILI. Methods. Sixty-four healthy C57Bl/6 mice were mechanically ventilated for 5 or 12 hours, using lower tidal volumes with positive end-expiratory pressure (PEEP) or higher tidal volumes without PEEP. Fifteen nonventilated mice served as controls. Results. All animals remained hemodynamically stable and survived MV protocols. In both MV groups, PaO2 to FiO2 ratios were lower and alveolar cell counts were higher after 12 hours of MV compared to 5 hours. Alveolar-capillary permeability was increased after 12 hours compared to 5 hours, although differences did not reach statistical significance. Lung levels of inflammatory mediators did not further increase over time. Only in mice ventilated with increased strain, lung compliance declined and wet to dry ratio increased after 12 hours of MV compared to 5 hours. Conclusions. Deleterious effects of MV are partly dependent on its duration. Even lower tidal volumes with PEEP may initiate aspects of VILI after 12 hours of MV. PMID:23691294

  3. The extent of ventilator-induced lung injury in mice partly depends on duration of mechanical ventilation.

    PubMed

    Hegeman, Maria A; Hemmes, Sabrine N T; Kuipers, Maria T; Bos, Lieuwe D J; Jongsma, Geartsje; Roelofs, Joris J T H; van der Sluijs, Koenraad F; Juffermans, Nicole P; Vroom, Margreeth B; Schultz, Marcus J

    2013-01-01

    Background. Mechanical ventilation (MV) has the potential to initiate ventilator-induced lung injury (VILI). The pathogenesis of VILI has been primarily studied in animal models using more or less injurious ventilator settings. However, we speculate that duration of MV also influences severity and character of VILI. Methods. Sixty-four healthy C57Bl/6 mice were mechanically ventilated for 5 or 12 hours, using lower tidal volumes with positive end-expiratory pressure (PEEP) or higher tidal volumes without PEEP. Fifteen nonventilated mice served as controls. Results. All animals remained hemodynamically stable and survived MV protocols. In both MV groups, PaO2 to FiO2 ratios were lower and alveolar cell counts were higher after 12 hours of MV compared to 5 hours. Alveolar-capillary permeability was increased after 12 hours compared to 5 hours, although differences did not reach statistical significance. Lung levels of inflammatory mediators did not further increase over time. Only in mice ventilated with increased strain, lung compliance declined and wet to dry ratio increased after 12 hours of MV compared to 5 hours. Conclusions. Deleterious effects of MV are partly dependent on its duration. Even lower tidal volumes with PEEP may initiate aspects of VILI after 12 hours of MV. PMID:23691294

  4. Compensation for increase in respiratory workload during mechanical ventilation. Pressure-support versus proportional-assist ventilation.

    PubMed

    Grasso, S; Puntillo, F; Mascia, L; Ancona, G; Fiore, T; Bruno, F; Slutsky, A S; Ranieri, V M

    2000-03-01

    Variation in respiratory impedance may occur in mechanically ventilated patients. During pressure-targeted ventilatory support, this may lead to patient-ventilator asynchrony. We assessed the hypothesis that during pressure-support ventilation (PSV), preservation of minute ventilation (V E) consequent to added mechanical loads would result in an increase in respiratory rate (RR) due to the large reduction in tidal volume (VT). WITH proportional-assist ventilation (PAV), preservation of V E would occur through the preservation of VT, with a smaller effect on RR. We anticipated that this compensatory strategy would result in greater patient comfort and a reduce work of breathing. An increase in respiratory impedance was obtained by chest and abdominal binding in 10 patients during weaning from mechanical ventilation. V E remained constant in both ventilatory modes after chest and abdominal compression. During PSV, this maintenance of VE was obtained through a 58 +/- 3% increase in RR that compensated for a 29 +/- 2% reduction in VT. The magnitudes of the reduction in VT (10 +/- 3%) and of the increase in RR (14 +/- 2%) were smaller (p < 0. 001) during PAV. During both PSV and PAV, chest and abdominal compression caused increases in both the pressure-time product (PTP) of the diaphragm per minute (142.9 +/- 26.9 cm H(2)O. s/min, PSV, and 117.6 +/- 16.4 cm H(2)O. s/min, PAV) and per liter (13.4 +/- 2.5 cm H(2)O. s/L, PSV, and 9.6 +/- 0.7 cm H(2)O. s/L, PAV). These increments were greater (p < 0.001) during PSV than during PAV. The capability of keeping VT and V E constant through increases in inspiratory effort after increases in mechanical loads is relatively preserved only during PAV. The ventilatory response to an added respiratory load during PSV required greater muscle effort than during PAV. PMID:10712328

  5. Quantitative investigation of alveolar structures with OCT using total liquid ventilation during mechanical ventilation

    NASA Astrophysics Data System (ADS)

    Schnabel, Christian; Gaertner, Maria; Meissner, Sven; Koch, Edmund

    2012-02-01

    To develop new treatment possibilities for patients with severe lung diseases it is crucial to understand the lung function on an alveolar level. Optical coherence tomography (OCT) in combination with intravital microscopy (IVM) are used for imaging subpleural alveoli in animal models to gain information about dynamic and morphological changes of lung tissue during mechanical ventilation. The image content suitable for further analysis is influenced by image artifacts caused by scattering, refraction, reflection, and absorbance. Because the refractive index varies with each air-tissue interface in lung tissue, these effects decrease OCT image quality exceedingly. The quality of OCT images can be increased when the refractive index inside the alveoli is matched to the one of tissue via liquid-filling. Thereby, scattering loss can be decreased and higher penetration depth and tissue contrast can be achieved. To use the advantages of liquid-filling for in vivo imaging of small rodent lungs, a suitable breathing fluid (perfluorodecalin) and a special liquid respirator are necessary. Here we show the effect of liquid-filling on OCT and IVM image quality of subpleural alveoli in a mouse model.

  6. Influence of inertance on respiratory mechanics measurements in mechanically ventilated puppies.

    PubMed

    Lanteri, C J; Petak, F; Gurrin, L; Sly, P D

    1999-08-01

    The complete equation of motion for a single compartment model (SCM) includes an inertance term to describe pressure changes in phase with acceleration, as well as terms for resistance and elastance. Inertance has traditionally been excluded from the model when measuring respiratory mechanics at conventional ventilatory frequencies in mature respiratory systems. However, this omission has been questioned recently for measurements of respiratory mechanics in intubated infants where higher ventilation frequencies and smaller tracheal tubes are the norm. We investigated 1) the significance of inertance in an immature respiratory system during mechanical ventilation, and 2) the effect of omitting it from the model on estimates of respiratory mechanics. Six anesthetised, paralysed and mechanically ventilated puppies (2.6-3.9 kg) were studied. A SCM, including an inertance term was fitted to measurements of flow and airway opening (P(AO)) or transpulmonary (P(TP)) pressure using multiple linear regression to estimate respiratory system and lung resistance (R(RS), R(L)), elastance (E(RS), E(L)) and inertance (I(RS), I(L)) respectively, at various ventilation frequencies (0.2-2 Hz). Data obtained at each ventilation frequency were also fitted with a similar model without the inertance term. Inertance contributed significantly to the model at frequencies greater than approximately 0.3-0.5 Hz (20-30 breaths per minute), with I(RS) dominated by the lung. The importance of including the inertance term in the model increased as ventilation frequency increased. Exclusion of inertance from the model led to underestimation of E(RS) and E(L), but no errors in estimates of R(RS) or R(L). The errors increased with ventilation frequency to approximately 10-20% for E(RS) and approximately 10-40% for E(L) at 2 Hz. While inertance contributed significantly to the SCM at ventilation frequencies typically required to maintain normal gas exchange in puppies, the errors from excluding this

  7. Model-based advice for mechanical ventilation: From research (INVENT) to product (Beacon Caresystem).

    PubMed

    Rees, Stephen E; Karbing, Dan S

    2015-01-01

    This paper describes the structure and functionality of a physiological model-based system for providing advice on the settings of mechanical ventilation. Use of the system is presented with examples of patients on support and control modes of mechanical ventilation. PMID:26737495

  8. Description of Peripheral Muscle Strength Measurement and Correlates of Muscle Weakness in Patients Receiving Prolonged Mechanical Ventilatory Support

    PubMed Central

    Chlan, Linda L.; Tracy, Mary Fran; Guttormson, Jill; Savik, Kay

    2015-01-01

    Background Intensive Care Unit Acquired Weakness (ICUAW) is a frequent complication of critical illness due to immobility and prolonged mechanical ventilatory support. Objectives To describe daily peripheral muscle strength measurement in ventilated patients and explore relationships among factors that influence ICUAW. Methods Peripheral muscle strength of 120 ventilated ICU patients (mean age 59.8 ± 15.1; 51% female; APACHE III 61.3 ± 20.7; ICU stay 10.6 ± 8.6 days) was measured daily using a standardized hand grip dynamometry protocol. Three grip measurements for each hand were recorded in pounds-force; the mean of these three assessments was used in the analysis. Correlates of ICUAW were analyzed with mixed models to explore their relationship to grip strength (age, gender, illness severity, length of ventilatory support, medications). Results Median baseline grip strength was variable yet diminished (7.7; 0-102) with either a pattern of diminishing grip strength or maintenance of the baseline low grip strength over time. Controlling for days on protocol, female gender [β = −10.4(2.5); p = <.001], age [= −.24(.08); p = .004], and days receiving ventilatory support [= −.34(.12); p = .005] explained a significant amount of variance in grip strength over time. Conclusions Patients receiving prolonged periods of mechanical ventilatory support in this sample show marked decrements in grip strength measured by hand dynamometry, a marker for peripheral muscle strength. Hand dynamometry is a reliable method to measure muscle strength in cooperative ICU patients and can be used in future research to ultimately develop interventions to prevent ICUAW. PMID:26523017

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

    PubMed

    Guler, Hasan; Ata, Fikret

    2014-09-01

    The aim of this article is to develop a knowledge-based therapy for management of rats with respiratory distress. A mechanical ventilator was designed to achieve this aim. The designed ventilator is called an intelligent mechanical ventilator since fuzzy logic was used to control the pneumatic equipment according to the rat's status. LabVIEW software was used to control all equipments in the ventilator prototype and to monitor respiratory variables in the experiment. The designed ventilator can be controlled both manually and by fuzzy logic. Eight female Wistar-Albino rats were used to test the designed ventilator and to show the effectiveness of fuzzy control over manual control on pressure control ventilation mode. The anesthetized rats were first ventilated for 20 min manually. After that time, they were ventilated for 20 min by fuzzy logic. Student's t-test for p < 0.05 was applied to the measured minimum, maximum and mean peak inspiration pressures to analyze the obtained results. The results show that there is no statistical difference in the rat's lung parameters before and after the experiments. It can be said that the designed ventilator and developed knowledge-based therapy support artificial respiration of living things successfully. PMID:25205667

  10. Upright position mechanical ventilation: an alternative strategy for ALI/ARDS patients?

    PubMed

    Zhu, Min; Zhang, Wei; Wang, Jia-Ning; Yan, Hua; Li, Yang-Kai; Ai, Bo; Fu, Sheng-Lin; Fu, Xiang-Ning

    2009-11-01

    Use of body positioning to improve oxygenation in mechanically ventilated patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) has been well documented. However, neither prone position ventilation nor side lying ventilation has been reported to improve the survival. Whether there is a body position superior to routine supine position or other positions as therapeutic adjunct for ventilated patients with ALI and ARDS? We propose the hypothesis that upright position ventilation may be helpful to improve oxygenation and benefit patients with ALI/ARDS. According to the existing physiologic and pathophysiologic data of upright position investigation, we suppose that improvement of V/Q matching, increased functional residual capacity, alveolar recruitment, accelerated diaphragm recovery, early gastric emptying and enteric feeding may be a potential protect mechanism of upright position ventilation. Whether this can be translated into improvement in patient outcome should be further tested in clinical trial. PMID:19683402

  11. Lung Injury After One-Lung Ventilation: A Review of the Pathophysiologic Mechanisms Affecting the Ventilated and the Collapsed Lung.

    PubMed

    Lohser, Jens; Slinger, Peter

    2015-08-01

    Lung injury is the leading cause of death after thoracic surgery. Initially recognized after pneumonectomy, it has since been described after any period of 1-lung ventilation (OLV), even in the absence of lung resection. Overhydration and high tidal volumes were thought to be responsible at various points; however, it is now recognized that the pathophysiology is more complex and multifactorial. All causative mechanisms known to trigger ventilator-induced lung injury have been described in the OLV setting. The ventilated lung is exposed to high strain secondary to large, nonphysiologic tidal volumes and loss of the normal functional residual capacity. In addition, the ventilated lung experiences oxidative stress, as well as capillary shear stress because of hyperperfusion. Surgical manipulation and/or resection of the collapsed lung may induce lung injury. Re-expansion of the collapsed lung at the conclusion of OLV invariably induces duration-dependent, ischemia-reperfusion injury. Inflammatory cytokines are released in response to localized injury and may promote local and contralateral lung injury. Protective ventilation and volatile anesthesia lessen the degree of injury; however, increases in biochemical and histologic markers of lung injury appear unavoidable. The endothelial glycocalyx may represent a common pathway for lung injury creation during OLV, because it is damaged by most of the recognized lung injurious mechanisms. Experimental therapies to stabilize the endothelial glycocalyx may afford the ability to reduce lung injury in the future. In the interim, protective ventilation with tidal volumes of 4 to 5 mL/kg predicted body weight, positive end-expiratory pressure of 5 to 10 cm H2O, and routine lung recruitment should be used during OLV in an attempt to minimize harmful lung stress and strain. Additional strategies to reduce lung injury include routine volatile anesthesia and efforts to minimize OLV duration and hyperoxia. PMID:26197368

  12. Anaesthesia ventilators

    PubMed Central

    Jain, Rajnish K; Swaminathan, Srinivasan

    2013-01-01

    Anaesthesia ventilators are an integral part of all modern anaesthesia workstations. Automatic ventilators in the operating rooms, which were very simple with few modes of ventilation when introduced, have become very sophisticated with many advanced ventilation modes. Several systems of classification of anaesthesia ventilators exist based upon various parameters. Modern anaesthesia ventilators have either a double circuit, bellow design or a single circuit piston configuration. In the bellows ventilators, ascending bellows design is safer than descending bellows. Piston ventilators have the advantage of delivering accurate tidal volume. They work with electricity as their driving force and do not require a driving gas. To enable improved patient safety, several modifications were done in circle system with the different types of anaesthesia ventilators. Fresh gas decoupling is a modification done in piston ventilators and in descending bellows ventilator to reduce th incidence of ventilator induced volutrauma. In addition to the conventional volume control mode, modern anaesthesia ventilators also provide newer modes of ventilation such as synchronised intermittent mandatory ventilation, pressure-control ventilation and pressure-support ventilation (PSV). PSV mode is particularly useful for patients maintained on spontaneous respiration with laryngeal mask airway. Along with the innumerable benefits provided by these machines, there are various inherent hazards associated with the use of the ventilators in the operating room. To use these workstations safely, it is important for every Anaesthesiologist to have a basic understanding of the mechanics of these ventilators and breathing circuits. PMID:24249886

  13. Oxidative stress is required for mechanical ventilation-induced protease activation in the diaphragm

    PubMed Central

    Smuder, Ashley J.; Wu, Min; Hudson, Matthew B.; Nelson, W. Bradley; Powers, Scott K.

    2010-01-01

    Prolonged mechanical ventilation (MV) results in diaphragmatic weakness due to fiber atrophy and contractile dysfunction. Recent work reveals that activation of the proteases calpain and caspase-3 is required for MV-induced diaphragmatic atrophy and contractile dysfunction. However, the mechanism(s) responsible for activation of these proteases remains unknown. To address this issue, we tested the hypothesis that oxidative stress is essential for the activation of calpain and caspase-3 in the diaphragm during MV. Cause-and-effect was established by prevention of MV-induced diaphragmatic oxidative stress using the antioxidant Trolox. Treatment of animals with Trolox prevented MV-induced protein oxidation and lipid peroxidation in the diaphragm. Importantly, the Trolox-mediated protection from MV-induced oxidative stress prevented the activation of calpain and caspase-3 in the diaphragm during MV. Furthermore, the avoidance of MV-induced oxidative stress not only averted the activation of these proteases but also rescued the diaphragm from MV-induced diaphragmatic myofiber atrophy and contractile dysfunction. Collectively, these findings support the prediction that oxidative stress is required for MV-induced activation of calpain and caspase-3 in the diaphragm and are consistent with the concept that antioxidant therapy can retard MV-induced diaphragmatic weakness. PMID:20203072

  14. Estimates of the demand for mechanical ventilation in the United States during an influenza pandemic.

    PubMed

    Meltzer, Martin I; Patel, Anita; Ajao, Adebola; Nystrom, Scott V; Koonin, Lisa M

    2015-05-01

    An outbreak in China in April 2013 of human illnesses due to avian influenza A(H7N9) virus provided reason for US public health officials to revisit existing national pandemic response plans. We built a spreadsheet model to examine the potential demand for invasive mechanical ventilation (excluding "rescue therapy" ventilation). We considered scenarios of either 20% or 30% gross influenza clinical attack rate (CAR), with a "low severity" scenario with case fatality rates (CFR) of 0.05%-0.1%, or a "high severity" scenario (CFR: 0.25%-0.5%). We used rates-of-influenza-related illness to calculate the numbers of potential clinical cases, hospitalizations, admissions to intensive care units, and need for mechanical ventilation. We assumed 10 days ventilator use per ventilated patient, 13% of total ventilator demand will occur at peak, and a 33.7% weighted average mortality risk while on a ventilator. At peak, for a 20% CAR, low severity scenario, an additional 7000 to 11,000 ventilators will be needed, averting a pandemic total of 35,000 to 55,000 deaths. A 30% CAR, high severity scenario, will need approximately 35,000 to 60,500 additional ventilators, averting a pandemic total 178,000 to 308,000 deaths. Estimates of deaths averted may not be realized because successful ventilation also depends on sufficient numbers of suitably trained staff, needed supplies (eg, drugs, reliable oxygen sources, suction apparatus, circuits, and monitoring equipment) and timely ability to match access to ventilators with critically ill cases. There is a clear challenge to plan and prepare to meet demands for mechanical ventilators for a future severe pandemic. PMID:25878301

  15. Non-invasive mechanical ventilation: the benefits of the BiPAP system.

    PubMed

    Teba, L; Marks, P; Benzo, R

    1996-01-01

    Many of the complications with endotracheal intubation and invasive mechanical ventilation can be avoided with the use of non-invasive mechanical ventilation (NIMV). This technique has been especially successful in treating patients with acute respiratory failure (ARF). NIMV improves gas exchange, avoids complications caused by endotracheal intubation, and allows patients to talk and take medications orally. This article reviews our experiences treating 27 patients with ARF with a BiPAP (bi-level positive airway pressure) ventilator. This is a portable unit which allows for selection of different modes of ventilation and adjustment of inspiratory and expiratory pressures. Non-invasive mechanical ventilation should be considered in patients presenting with ARF who are hemodynamically stable and in whom spontaneous breathing is preserved. PMID:8599242

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

    NASA Astrophysics Data System (ADS)

    Vanrhein, Timothy; Banerjee, Arindam

    2010-11-01

    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.

  17. Clinical Outcomes Associated with Home Mechanical Ventilation: A Systematic Review.

    PubMed

    MacIntyre, Erika J; Asadi, Leyla; Mckim, Doug A; Bagshaw, Sean M

    2016-01-01

    Background. The prevalence of patients supported with home mechanical ventilation (HMV) for chronic respiratory failure has increased. However, the clinical outcomes associated with HMV are largely unknown. Methods. We performed a systematic review of studies evaluating patients receiving HMV for indications other than obstructive lung disease, reporting at least one clinically relevant outcome including health-related quality of life (HRQL) measured by validated tools; hospitalization requirements; caregiver burden; and health service utilization. We searched MEDLINE, EMBASE, CINAHL, the Cochrane library, clinical trial registries, proceedings from selected scientific meetings, and bibliographies of retrieved citations. Results. We included 1 randomized control trial (RCT) and 25 observational studies of mixed methodological quality involving 4425 patients; neuromuscular disorders (NMD) (n = 1687); restrictive thoracic diseases (RTD) (n = 481); obesity hypoventilation syndrome (OHS) (n = 293); and others (n = 748). HRQL was generally described as good for HMV users. Mental rather than physical HRQL domains were rated higher, particularly where physical assessment was limited. Hospitalization rates and days in hospital appear to decrease with implementation of HMV. Caregiver burden associated with HMV was generally high; however, it is poorly described. Conclusion. HRQL and need for hospitalization may improve after establishment of HMV. These inferences are based on relatively few studies of marked heterogeneity and variable quality. PMID:27445559

  18. Clinical Outcomes Associated with Home Mechanical Ventilation: A Systematic Review

    PubMed Central

    MacIntyre, Erika J.; Asadi, Leyla; Mckim, Doug A.; Bagshaw, Sean M.

    2016-01-01

    Background. The prevalence of patients supported with home mechanical ventilation (HMV) for chronic respiratory failure has increased. However, the clinical outcomes associated with HMV are largely unknown. Methods. We performed a systematic review of studies evaluating patients receiving HMV for indications other than obstructive lung disease, reporting at least one clinically relevant outcome including health-related quality of life (HRQL) measured by validated tools; hospitalization requirements; caregiver burden; and health service utilization. We searched MEDLINE, EMBASE, CINAHL, the Cochrane library, clinical trial registries, proceedings from selected scientific meetings, and bibliographies of retrieved citations. Results. We included 1 randomized control trial (RCT) and 25 observational studies of mixed methodological quality involving 4425 patients; neuromuscular disorders (NMD) (n = 1687); restrictive thoracic diseases (RTD) (n = 481); obesity hypoventilation syndrome (OHS) (n = 293); and others (n = 748). HRQL was generally described as good for HMV users. Mental rather than physical HRQL domains were rated higher, particularly where physical assessment was limited. Hospitalization rates and days in hospital appear to decrease with implementation of HMV. Caregiver burden associated with HMV was generally high; however, it is poorly described. Conclusion. HRQL and need for hospitalization may improve after establishment of HMV. These inferences are based on relatively few studies of marked heterogeneity and variable quality. PMID:27445559

  19. Evaluation of Pain Assessment Tools in Patients Receiving Mechanical Ventilation.

    PubMed

    Al Darwish, Zainab Q; Hamdi, Radwa; Fallatah, Summayah

    2016-01-01

    Pain assessment poses a great challenge for clinicians in intensive care units. This descriptive study aimed to find the most reliable, sensitive, and valid tool for assessing pain. The researcher and a nurse simultaneously assessed 47 nonverbal patients receiving mechanical ventilation in the intensive care unit by using 3 tools: the Behavioral Pain Scale (BPS), the Critical-Care Pain Observation Tool (CPOT), and the adult Nonverbal Pain Scale (NVPS) before, during, and after turning and suctioning. All tools were found to be reliable and valid (Cronbach α = 0.95 for both the BPS and the CPOT, α = 0.86 for the NVPS), and all subscales of both the BPS and CPOT were highly sensitive for assessing pain (P < .001). The NVPS physiology (P = .21) and respiratory (P = .16) subscales were not sensitive for assessing pain. The BPS was the most reliable, valid, and sensitive tool, with the CPOT considered an appropriate alternative tool for assessing pain. The NVPS is not recommended because of its inconsistent psychometric properties. PMID:27153305

  20. [A new view on pathochemical mechanisms of prolonged peritoneal dialysis].

    PubMed

    Petrovich, Iu A; Iarema, I V; Terekhina, N A; Kichenko, S M

    2010-01-01

    New data on etiology, pathogenesis, clinics, quantity estimation, treatment and complications of peritoneal dialysis are observed. The role of aquaporine, nitric oxide, NO-synthase, inflammation and sepsis markers (procalcitonine, C-reactive protein) in pathochemical mechanism of peritoneal dialysis is discussed. PMID:20734476

  1. Dietary antiaging phytochemicals and mechanisms associated with prolonged survival

    PubMed Central

    Si, Hongwei; Liu, Dongmin

    2014-01-01

    Aging is well-known an inevitable process that is influenced by genetic, lifestyle and environmental factors. However, the exact mechanisms underlying the aging process are not well understood. Increasing evidence shows that aging is highly associated with chronic increase in reactive oxygen species (ROS), accumulation of a low-grade proinflammatory phenotype and reduction in age-related autophagy, suggesting that these factors may play important roles in promoting aging. Indeed, reduction of ROS and low-grade inflammation and promotion of autophagy by calorie restriction or other dietary manipulation can extend lifespan in a wide spectrum of model organisms. Interestingly, recent studies show that some food-derived small molecules, also called phytochemicals, can extend lifespan in various animal species. In this paper, we review several recently identified potential antiaging phytochemicals that have been studied in cells, animals and humans and further highlight the cellular and molecular mechanisms underlying the antiaging actions by these molecules. PMID:24742470

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

    PubMed

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

    2016-08-01

    The aim of this present study is to compare the effect of pressure-controlled ventilation and volume-controlled ventilation on pulmonary mechanics and inflammatory markers in prone position. The study included 41 patients undergoing to vertebrae surgery. The patients were randomized into two groups: Group 1 received volume-controlled ventilation, while group 2 received pressure-controlled ventilation. The demographic data, pulmonary mechanics, the inflammatory marker levels just after the induction of anesthetics, at the 6th and 12th hours, and gas analysis from arterial blood samples taken at the beginning and the 30th minute were recorded. The inflammatory marker levels increased in both groups, without any significant difference among groups. Peak inspiratory pressure level was higher in the volume-controlled ventilation group. This study revealed that there is no difference regarding inflammatory marker levels between volume- and pressure-controlled ventilation. PMID:27221140

  3. [High frequency jet ventilation combined with conventional mechanical ventilation in the treatment of adult respiratory distress syndrome].

    PubMed

    Roustan, J P

    1995-01-01

    Better understanding of the physiopathology of ventilatory mechanisms associated with ARDS and the recent re-evaluation of the iatrogenic potential of mechanical ventilation (MV) brings us closer to the best suited ventilatory mode for these patients. In severely ill ARDS patients, only a small lung volume is ventilated, and remains available for the totality of the gas exchanges (baby lung concept). The goal of MV is to restore and maintain an optimal exchange volume while limiting mechanical agression of the lung tissue. Analysis of the ARDS related pressure-volume relationship (P/V) is helpful in specifying the tolerable limits of the ventilatory pressure regimen. The lower limit (end expiratory pressure) must be kept above the lower inflexion point of the curve, in order to increase the ventilated lung volume and avoid distal airway collapse. Under this limit, gas exchanges are altered by the shunt effect, and shear stress lesions result from the repeated opening and closing of the distal airways. The upper limit (end inspiratory pressure) must be situated below the upper inflexion point of the curve, in order to avoid lesions resulting from surdistension of the alveolocapillary membranes and barotraumatisms. The only way to position MV in such a narrow pressure window, is to greatly reduce the tidal volume (VT). Though CO2 retention would inevitably occur under conventional MV conditions, high frequency ventilation (HFV) seems better adapted to these theoreotical objectives; small VT's are injected under a limited amplitude pressure regimen and a satisfactory CO2 clearance is maintained. This ventilatory mode, existing since more than 15 years, has recently benefited from many technical improvements as well as the concept of oscillating the ventilation around a selected mean pressure in the central region of the P/V curve. In the past, HFV was applied using low pressure regimens, situated below the lower inflexion point of the curve. The resulting failures are

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  5. MEASUREMENT OF AMMONIA EMISSIONS FROM MECHANICALLY VENTILATED POULTRY HOUSES USING MULTIPATH TUNABLE DIODE LASER SPECTROSCOPY

    EPA Science Inventory

    Ammonia emissions from mechanically ventilated poultry operations are an important environmental concern. Open Path Tunable Diode Laser Absorption Spectroscopy has emerged as a robust real-time method for gas phase measurement of ammonia concentrations in agricultural settings. ...

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

    SciTech Connect

    Hurford, W.E.; Lynch, K.E.; Strauss, H.W.; Lowenstein, E.; Zapol, W.M. )

    1991-06-01

    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.

  7. Rocking bed and prolonged independence from nocturnal non-invasive ventilation in neurogenic respiratory failure associated with limb weakness

    PubMed Central

    Cormican, L; Higgins, S; Davidson, A; Howard, R; Williams, A

    2004-01-01

    A 40 year old mother of three with autosomal dominant scapuloperoneal muscular dystrophy presented with severe neurogenic respiratory failure requiring nocturnal non-invasive ventilation (NIV). Because of the development of profound proximal muscular weakness as a consequence of the progressive nature of her neurological disease, she eventually was unable to apply and remove the facial interface to set up her NIV circuit. She therefore became dependent on her children and carers to start and stop NIV during the night. A rocking bed was successfully employed as an alternative to nocturnal NIV. Ventilation was facilitated by the passive movement of the diaphragm as a consequence of the movement of the abdominal contents under the effect of gravity. Benefit was demonstrated objectively by pulse oximetry and subjectively by the improvement in the patient's symptomatology and continued independence at night. The ease of use of a rocking bed should be borne in mind when the necessity for nocturnal ventilatory support in neuromuscular disease results in the potential loss of independence for a patient. PMID:15192173

  8. Assisted Ventilation.

    PubMed

    Dries, David J

    2016-01-01

    Controlled Mechanical Ventilation may be essential in the setting of severe respiratory failure but consequences to the patient including increased use of sedation and neuromuscular blockade may contribute to delirium, atelectasis, and diaphragm dysfunction. Assisted ventilation allows spontaneous breathing activity to restore physiological displacement of the diaphragm and recruit better perfused lung regions. Pressure Support Ventilation is the most frequently used mode of assisted mechanical ventilation. However, this mode continues to provide a monotonous pattern of support for respiration which is normally a dynamic process. Noisy Pressure Support Ventilation where tidal volume is varied randomly by the ventilator may improve ventilation and perfusion matching but the degree of support is still determined by the ventilator. Two more recent modes of ventilation, Proportional Assist Ventilation and Neurally Adjusted Ventilatory Assist (NAVA), allow patient determination of the pattern and depth of ventilation. Proposed advantages of Proportional Assist Ventilation and NAVA include decrease in patient ventilator asynchrony and improved adaptation of ventilator support to changing patient demand. Work of breathing can be normalized with these modes as well. To date, however, a clear pattern of clinical benefit has not been demonstrated. Existing challenges for both of the newer assist modes include monitoring patients with dynamic hyperinflation (auto-positive end expiratory pressure), obstructive lung disease, and air leaks in the ventilator system. NAVA is dependent on consistent transduction of diaphragm activity by an electrode system placed in the esophagus. Longevity of effective support with this technique is unclear. PMID:25501776

  9. Impact of Residential Mechanical Ventilation on Energy Cost and Humidity Control

    SciTech Connect

    Martin, Eric

    2014-01-01

    Optimizing whole house mechanical ventilation as part of the Building Ameerica program's systems engineered approach to constructing housing has been an important subject of the program's research. Ventilation in residential buildings is one component of an effective, comprehensive strategy for creation and maintenance of a comfortable and healthy indoor air environment. The study described in this report is based on building energy modeling with an important focus on the indoor humidity impacts of ventilation. The modeling tools used were EnergyPlus version 7.1 (E+) and EnergyGauge USA (EGUSA). Twelve U.S. cities and five climate zones were represented. A total of 864 simulations (2*2*3*3*12= 864) were run using two building archetypes, two building leakage rates, two building orientations, three ventilation systems, three ventilation rates, and twelve climates.

  10. Impact of Residential Mechanical Ventilation on Energy Cost and Humidity Control

    SciTech Connect

    Martin, E.

    2014-01-01

    The DOE Building America program has been conducting research leading to cost effective high performance homes since the early 1990's. Optimizing whole house mechanical ventilation as part of the program's systems engineered approach to constructing housing has been an important subject of the program's research. Ventilation in residential buildings is one component of an effective, comprehensive strategy for creation and maintenance of a comfortable and healthy indoor air environment. The study described in this white paper is based on building energy modeling with an important focus on the indoor humidity impacts of ventilation. The modeling tools used were EnergyPlus version 7.1 (E+) and EnergyGauge USA (EGUSA). Twelve U.S. cities and five climate zones were represented. A total of 864 simulations (2*2*3*3*12= 864) were run using two building archetypes, two building leakage rates, two building orientations, three ventilation systems, three ventilation rates, and twelve climates.

  11. Mechanics of ventilation in swellsharks, Cephaloscyllium ventriosum (Scyliorhinidae).

    PubMed

    Ferry-Graham, L A

    1999-06-01

    A simple two-pump model has served to describe the mechanics of ventilation in cartilaginous and bony fishes since the pioneering work of G. M. Hughes. A hallmark of this model is that water flow over the gills is continuous. Studies of feeding kinematics in the swellshark Cephaloscyllium ventriosum, however, suggested that a flow reversal occurred during prey capture and transport. Given that feeding is often considered to be simply an exaggeration of the kinematic events performed during respiration, I investigated whether flow reversals are potentially present during respiration. Pressure and impedance data were coupled with kinematic data from high-speed video footage and dye studies and used to infer patterns of water flow through the heads of respiring swellsharks. Swellsharks were implanted with pressure transducers to determine the pattern and magnitude of pressures generated within the buccal and parabranchial (gill) cavities during respiration. Pressure traces revealed extended periods of pressure reversal during the respiratory cycle. Further, impedance data suggested that pressures within the buccal and parabranchial cavities were not generated by the cyclic opening and closing of the jaws and gills in the manner previously suggested by Hughes. Thus, the classic model needs to be re-evaluated to determine its general applicability. Two alternative models for pressure patterns and their mechanism of generation during respiration are provided. The first depicts a double-reversal scenario common in the swellshark whereby pressures are reversed following both of the pump stages (the suction pump and the pressure pump) rather than after the pressure-pump stage only. The second model describes a scenario in which the suction pump is insufficient for generating a positive pressure differential across the gills; thus, a pressure reversal persists throughout this phase of respiration. Kinematic analysis based on high-speed video footage and dye studies, however

  12. Effect of early mobilization on discharge disposition of mechanically ventilated patients

    PubMed Central

    Ota, Hideki; Kawai, Hideki; Sato, Makoto; Ito, Kazuaki; Fujishima, Satoshi; Suzuki, Hiroko

    2015-01-01

    [Purpose] The purpose of this study was to clarify the benefits of early mobilization for mechanically ventilated patients for their survival to discharge to home from the hospital. [Subjects and Methods] Medical records were retrospectively analyzed of patients who satisfied the following criteria: age ≥ 18 years; performance status 0–2 and independent living at their home before admission; mechanical ventilation for more than 48 h; and survival after mechanical ventilation. Mechanically ventilated patients in the early mobilization (EM) group (n = 48) received mobilization therapy, limb exercise and chest physiotherapy, whereas those in the control group (n = 60) received bed rest alone. Univariate and multivariate logistic regression analyses were performed to identify clinical variables associated with discharge disposition. [Results] Early mobilization was a positive independent factor and the presence of neurological deficits was a negative factor contributing to discharge to home. Among patients surviving mechanical ventilation without neurological deficits, the rate of discharge to home was significantly higher among patients in the EM group that in the control group (76% vs. 40%). [Conclusion] Early mobilization can improve the rate of discharge to home of patients requiring mechanical ventilation because of non-neurological deficits. PMID:25931747

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

    SciTech Connect

    Sherman, Max; Logue, Jennifer; Singer, Brett

    2010-06-01

    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.

  14. Measured Air Distribution Effectiveness for Residential Mechanical Ventilation Systems

    SciTech Connect

    Sherman, Max; Sherman, Max H.; Walker, Iain S.

    2008-05-01

    The purpose of ventilation is dilute or remove indoor contaminants that an occupant is exposed to. In a multi-zone environment such as a house, there will be different dilution rates and different source strengths in every zone. Most US homes have central HVAC systems, which tend to mix the air thus the indoor conditions between zones. Different types of ventilation systems will provide different amounts of exposure depending on the effectiveness of their air distribution systems and the location of sources and occupants. This paper will report on field measurements using a unique multi-tracer measurement system that has the capacity to measure not only the flow of outdoor air to each zone, but zone-to-zone transport. The paper will derive seven different metrics for the evaluation of air distribution. Measured data from two homes with different levels of natural infiltration will be used to evaluate these metrics for three different ASHRAE Standard 62.2 compliant ventilation systems. Such information can be used to determine the effectiveness of different systems so that appropriate adjustments can be made in residential ventilation standards such as ASHRAE Standard 62.2.

  15. [Long-term effects of home mechanical ventilation with positive pressure using a nasal mask].

    PubMed

    Escarrabill, J; Estopà, R; Robert, D; Casolivé, V; Manresa, F

    1991-10-01

    Home mechanical ventilation (HMV) is an efficient alternative in the treatment of patients with chronic respiratory failure secondary to restrictive mechanical disorders (neuromuscular disease, such as Duchenne's disease, thorax deformities due to kyphoscoliosis or tuberculosis sequelae). The case of a patient with severe kyphoscoliosis in the phase of chronic respiratory failure (PaO2 34 mmHg and PaCO2 61 mmHg, breathing ambient air) is presented in which, following the failure of negative pressure mechanical ventilation ("poncho"), positive pressure ventilation was tested with a silicon made-to-measure nasal mask as the access via. Adaptation to HMV was good with the patient using the ventilation nightly. Following 12 months of treatment the patient is able to carry out everyday activities and arterial gasometry breathing ambient air is PaO2 77 mmHg and PaCO2 43 mmHg. PMID:1961049

  16. Particle Size Concentration Distribution and Influences on Exhaled Breath Particles in Mechanically Ventilated Patients

    PubMed Central

    Chen, Yi-Fang; Huang, Sheng-Hsiu; Wang, Yu-Ling; Chen, Chun-Wan

    2014-01-01

    Humans produce exhaled breath particles (EBPs) during various breath activities, such as normal breathing, coughing, talking, and sneezing. Airborne transmission risk exists when EBPs have attached pathogens. Until recently, few investigations had evaluated the size and concentration distributions of EBPs from mechanically ventilated patients with different ventilation mode settings. This study thus broke new ground by not only evaluating the size concentration distributions of EBPs in mechanically ventilated patients, but also investigating the relationship between EBP level and positive expiratory end airway pressure (PEEP), tidal volume, and pneumonia. This investigation recruited mechanically ventilated patients, with and without pneumonia, aged 20 years old and above, from the respiratory intensive care unit of a medical center. Concentration distributions of EBPs from mechanically ventilated patients were analyzed with an optical particle analyzer. This study finds that EBP concentrations from mechanically ventilated patients during normal breathing were in the range 0.47–2,554.04 particles/breath (0.001–4.644 particles/mL). EBP concentrations did not differ significantly between the volume control and pressure control modes of the ventilation settings in the mechanically ventilated patients. The patient EBPs were sized below 5 µm, and 80% of them ranged from 0.3 to 1.0 µm. The EBPs concentrations in patients with high PEEP (> 5 cmH2O) clearly exceeded those in patients with low PEEP (≤ 5 cmH2O). Additionally, a significant negative association existed between pneumonia duration and EBPs concentration. However, tidal volume was not related to EBPs concentration. PMID:24475230

  17. Early mechanical ventilation is deleterious after aspiration-induced lung injury in rabbits.

    PubMed

    Hermon, Michael M; Wassermann, Esther; Pfeiler, Claudia; Pollak, Arnold; Redl, Heinz; Strohmaier, Wolfgang

    2005-01-01

    We investigated whether mechanical ventilation after aspiration is deleterious when started before surfactant therapy. Gas exchange and lung mechanics were measured in rabbits after aspiration either mechanically ventilated before or after lavage with diluted surfactant or Ringer's solution. Lung injury was induced by intratracheal instillation of 2 mL/kg of a betain/HCl pepsin mixture. After 30 min of spontaneous breathing, ventilation was started in 12 rabbits, which were then treated by lavage with diluted surfactant (15 mL/kg body weight; 5.3 mg/mL, group MVpre S) or with Ringer's solution (1 mL/kg; group MVpre R). Another 12 rabbits were treated by lavage while spontaneously breathing and were then connected to the ventilator (MVpost S and MVpost R). Sham control rabbits were mechanically ventilated for 4 h. At the end of experiment, PaO2/FiO2 ratio in MVpost S was five times higher than in MVpre S (P=0.0043). Lung mechanics measurements showed significant difference between MVpre S and MVpost S (P=0.0072). There was histopathologic evidence of decreased lung injury in MVpost S. Immediate initiation of ventilation is harmful when lung injury is induced by aspiration. Further investigations are needed to clarify whether the timing of lavage with diluted surfactant has an impact on the treatment of patients with aspiration or comparable types of direct lung injury. PMID:15614133

  18. Total Liquid Ventilation Provides Superior Respiratory Support to Conventional Mechanical Ventilation in a Large Animal Model of Severe Respiratory Failure

    PubMed Central

    Pohlmann, Joshua R; Brant, David O; Daul, Morgan A; Reoma, Junewai L; Kim, Anne C; Osterholzer, Kathryn R; Johnson, Kent J; Bartlett, Robert H; Cook, Keith E; Hirschl, Ronald B

    2011-01-01

    Total liquid ventilation (TLV) has the potential to provide respiratory support superior to conventional mechanical ventilation (CMV) in the acute respiratory distress syndrome (ARDS). However, laboratory studies are limited to trials in small animals for no longer than 4 hours. The objective of this study was to compare TLV and CMV in a large animal model of ARDS for 24 hours. Ten sheep weighing 53 ± 4 (SD) kg were anesthetized and ventilated with 100% oxygen. Oleic acid was injected into the pulmonary circulation until PaO2:FiO2 ≥ 60 mmHg, followed by transition to a protective CMV protocol (n=5) or TLV (n=5) for 24 hours. Pathophysiology was recorded and the lungs were harvested for histological analysis. Animals treated with CMV became progressively hypoxic and hypercarbic despite maximum ventilatory support. Sheep treated with TLV maintained normal blood gases with statistically greater PO2 (p<10−9) and lower PCO2 (p < 10−3) than the CMV group. Survival at 24 hours in the TLV and CMV groups were 100% and 40% respectively (p< 0.05). Thus, TLV provided gas exchange superior to CMV in this laboratory model of severe ARDS. PMID:21084968

  19. A randomized study assessing the systematic search for maxillary sinusitis in nasotracheally mechanically ventilated patients. Influence of nosocomial maxillary sinusitis on the occurrence of ventilator-associated pneumonia.

    PubMed

    Holzapfel, L; Chastang, C; Demingeon, G; Bohe, J; Piralla, B; Coupry, A

    1999-03-01

    The objective of this randomized study was to compare the occurrence of nosocomial pneumonia in nasotracheally intubated patients who were randomly allocated either to a systematic search of sinusitis by CT scan (study group) or not (control group). A total of 399 patients were included: 272 male and 127 female; mean age, 61 +/- 17 yr; SAPS: 12.6 +/- 4.9. The study group consisted of 199 patients and the control group consisted of 200. In the study group, sinus CT scans were performed in case of fever at Days 4 and 8 and then every 7 d. Nosocomial sinusitis was defined as follows: fever of >/= 38 degrees C, radiographic (sinusal air-fluid level or opacification on CT scan) signs, and presence of purulent aspirate from the involved sinus puncture with >/= 10(3) cfu/ml. Patients with sinusitis received sinus lavage and intravenously administered antibiotics. In the study group, 80 patients experienced nosocomial sinusitis. In the control group, no patient was treated for a sinusitis. Ventilator-associated bronchopneumonia (VAP) was observed in 88 patients: 37 in the study group (1 mo Kaplan-Meier estimate, 34%) versus 51 in the control group (1 mo Kaplan-Meier estimate, 47%); (p = 0.02, log-rank test; relative risk [RR] = 0.61; 95% confidence interval [CI], 0.40 to 0.93). Two months overall mortality was estimated at 36% in the study group versus 46% in the control group (p = 0.03, log-rank test; RR = 0.71; 95% CI, 0.52 to 0.97). We conclude that the occurrence of VAP in patients undergoing prolonged mechanical ventilation via a nasotracheal intubation can be prevented by the systematic search and treatment of nosocomial sinusitis. The effect on mortality should be confirmed. PMID:10051239

  20. Initial mechanical ventilator settings for pediatric patients: clinical judgement in selection of tidal volume.

    PubMed

    Kanter, R K; Blatt, S D; Zimmerman, J J

    1987-03-01

    Guidelines for selection of initial mechanical ventilator settings for pediatric patients were evaluated. Protocols specifying tidal volume or peak inspiratory pressure are difficult to apply for infants and children because of leaks at uncuffed endotracheal tubes, compression loss in ventilators, and inaccuracy of settings for intended tidal volume. To avoid these difficulties, the selection of tidal volume was based on subjective clinical observations: visible chest excursion and audible air entry at least simulating normal breathing. In 76 consecutive patients, use of the guidelines resulted in satisfactory PaCO2 for 97% and PaO2 for 89% of infants and children with a wide variety of respiratory disorders. Adequacy of gas exchange was not related to the patient's age, type of ventilator, tightness of fit of the endotracheal tube, or presence of spontaneous breathing. These results support a simple, versatile method of teaching selection of initial mechanical ventilator settings, relying on clinical judgment for regulation of tidal volume. PMID:3470010

  1. Prolonged mechanical support in children with severe adenoviral infections: a case series and review of the literature.

    PubMed

    Gupta, Punkaj; Tobias, Joseph D; Goyal, Sunali; Hervie, Peter; Harris, Jason B; Sadot, Efraim; Noviski, Natan

    2011-01-01

    Adenovirus infections occur primarily in infants and children less than 5 years of age, accounting for 2% to 5% of respiratory illnesses in the pediatric population and 4% to 10% of childhood pneumonias. Although the majority of children with adenovirus disease develop mild upper respiratory tract disease, more severe disease may occur with involvement of the lower respiratory tract characterized by pneumonitis and/or small airways disease. The authors present a case series of 3 high-risk children with severe lower respiratory tract adenoviral infections. These cases demonstrate the potential for the development of severe respiratory involvement from adenovirus in infants and children with comorbid conditions and illustrate that there may be a rapid progression of the disease as well as the need, in selected circumstances, for prolonged mechanical support. We review the role of adenovirus in lower respiratory tract infections in infants and children, its potential to result in life-threatening complications in pediatric patients with comorbid conditions, and the potential life-saving role of mechanical ventilation and extracorporeal life support (ECLS) in these children. PMID:21320864

  2. [Noninvasive mechanical ventilation in patients with stable severe COPD].

    PubMed

    Schucher, B; Zerbst, J; Baumann, H J

    2004-06-01

    Noninvasive positive pressure ventilation in patients with stable chronic obstructive pulmonary disease. The role of non-invasive positive pressure ventilation (NIPPV) is well documented in patients with restrictive thoracic diseases like kyphoscoliosis, tuberculosis sequelae or neuromuscular disease. There is also a good evidence for the use of NIPPV in acute respiratory failure in patients with an exacerbation of COPD. The application of NIPPV in patients with chronic respiratory failure is growing, but there is less evidence than in restrictive disorders. NIPPV can unload the respiratory muscles in patients with chronic hypercapnic COPD and so alleviates fatigue of the respiratory pump, but improvement in the maximal inspiratory pressure (Pi (max)) is small or even absent. An improvement of sleep quality has also postulated, there was an increase in total sleep time and sleep effectiveness when using higher inspiratory pressure. An increase of the walking distance was shown in short term studies, only. In most studies, there was an increase in quality of life as a main topic. Mortality was unchanged in the two long-term randomised controlled studies. Current data suggest a possible role of NIPPV in patients with severe hypercapnia. A high effective inspiratory pressure and a ventilator mode with a significant reduction in the work of breathing should be choosen. NIPPV should be started in hospital, a close reassessment must be performed. Patients who accepted NIPPV in the first weeks had a good compliance for long-term use. PMID:15216436

  3. Effect of Alterations in Mechanical Ventilator Settings on Pulmonary Gas Exchange in Hyaline Membrane Disease

    PubMed Central

    Reynolds, E. O. R.

    1971-01-01

    The effect of altering peak airway pressure, respiratory frequency, and inspiration: expiration ratio on arterial blood gas tensions, blood pressure, and calculated right-to-left shunt was investigated in 6 infants undergoing mechanical ventilation for hyaline membrane disease with a Bennet ventilator. The use of a very long inspiratory phase resulted in a large increase in Pao2 and fall in right-to-left shunt without affecting mean arterial blood pressure. ImagesFIG. 1FIG. 4 PMID:5576023

  4. The rapid shallow breathing index as a predictor of successful mechanical ventilation weaning: clinical utility when calculated from ventilator data

    PubMed Central

    de Souza, Leonardo Cordeiro; Lugon, Jocemir Ronaldo

    2015-01-01

    ABSTRACT OBJECTIVE: The use of the rapid shallow breathing index (RSBI) is recommended in ICUs, where it is used as a predictor of mechanical ventilation (MV) weaning success. The aim of this study was to compare the performance of the RSBI calculated by the traditional method (described in 1991) with that of the RSBI calculated directly from MV parameters. METHODS: This was a prospective observational study involving patients who had been on MV for more than 24 h and were candidates for weaning. The RSBI was obtained by the same examiner using the two different methods (employing a spirometer and the parameters from the ventilator display) at random. In comparing the values obtained with the two methods, we used the Mann-Whitney test, Pearson's linear correlation test, and Bland-Altman plots. The performance of the methods was compared by evaluation of the areas under the ROC curves. RESULTS: Of the 109 selected patients (60 males; mean age, 62 ± 20 years), 65 were successfully weaned, and 36 died. There were statistically significant differences between the two methods for respiratory rate, tidal volume, and RSBI (p < 0.001 for all). However, when the two methods were compared, the concordance and the intra-observer variation coefficient were 0.94 (0.92-0.96) and 11.16%, respectively. The area under the ROC curve was similar for both methods (0.81 ± 0.04 vs. 0.82 ± 0.04; p = 0.935), which is relevant in the context of this study. CONCLUSIONS: The satisfactory performance of the RSBI as a predictor of weaning success, regardless of the method employed, demonstrates the utility of the method using the mechanical ventilator. PMID:26785962

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

    SciTech Connect

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

    2011-07-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    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.

  7. Atrial Fibrillation on Intensive Care Unit Admission Independently Increases the Risk of Weaning Failure in Nonheart Failure Mechanically Ventilated Patients in a Medical Intensive Care Unit

    PubMed Central

    Tseng, Yen-Han; Ko, Hsin-Kuo; Tseng, Yen-Chiang; Lin, Yi-Hsuan; Kou, Yu Ru

    2016-01-01

    Abstract Atrial fibrillation (AF) is one of the most frequent arrhythmias in clinical practice. Previous studies have reported the influence of AF on patients with heart failure (HF). The effect of AF on the non-HF critically ill patients in a medical intensive care unit (ICU) remains largely unclear. The study aimed to investigate the impact of AF presenting on ICU admission on the weaning outcome of non-HF mechanically ventilated patients in a medical ICU. A retrospective observational case–control study was conducted over a 1-year period in a medical ICU at Taipei Veterans General Hospital, a tertiary medical center in north Taiwan. Non-HF mechanically ventilated patients who were successful in their spontaneous breathing trial and underwent ventilator discontinuation were enrolled. The primary outcome measure was the ventilator status after the first episode of ventilator discontinuation. A total of 285 non-HF patients enrolled were divided into AF (n = 62) and non-AF (n = 223) groups. Compared with the non-AF patients, the AF patients were significantly associated with old age (P = 0.002), a higher rate of acute respiratory distress syndrome causing respiratory failure (P = 0.015), a higher percentage of sepsis before liberation from mechanical ventilation (MV) (P = 0.004), and a higher serum level of blood urea nitrogen on the day of liberation from MV (P = 0.003). Multivariate logistic regression analysis demonstrated that AF independently increased the risk of weaning failure [adjusted odds ratio (AOR), 3.268; 95% confidence interval (CI), 1.254–8.517; P = 0.015]. Furthermore, the AF patients were found to be independently associated with a high rate of ventilator dependence (log rank test, P = 0.026), prolonged total ventilator use (AOR, 1.979; 95% CI, 1.032–3.794; P = 0.040), increased length of ICU stay (AOR, 2.256; 95% CI, 1.049–4.849; P = 0.037), increased length of hospital stay (AOR, 2.921; 95% CI, 1

  8. Non invasive monitoring in mechanically ventilated pediatric patients.

    PubMed

    Al-Subu, Awni M; Rehder, Kyle J; Cheifetz, Ira M; Turner, David A

    2014-12-01

    Cardiopulmonary monitoring is a key component in the evaluation and management of critically ill patients. Clinicians typically rely on a combination of invasive and non-invasive monitoring to assess cardiac output and adequacy of ventilation. Recent technological advances have led to the introduction: of continuous non-invasive monitors that allow for data to be obtained at the bedside of critically ill patients. These advances help to identify hemodynamic changes and allow for interventions before complications occur. In this manuscript, we highlight several important methods of non-invasive cardiopulmonary monitoring, including capnography, transcutaneous monitoring, pulse oximetry, and near infrared spectroscopy. PMID:25119483

  9. Pulmonary Drug Delivery System for inhalation therapy in mechanically ventilated patients.

    PubMed

    Dhand, Rajiv; Sohal, Harjyot

    2008-01-01

    The Pulmonary Drug Delivery System (PDDS) Clinical represents a newer generation of electronic nebulizers that employ a vibrating mesh or aperture plate to generate an aerosol. The PDDS Clinical is designed for aerosol therapy in patients receiving mechanical ventilation. The components of the device include a control module that is connected to the nebulizer/reservoir unit by a cable. The nebulizer contains Aerogen's OnQ aerosol generator. A pressure sensor monitors the pressure in the inspiratory limb of the ventilator circuit and provides feedback to the control module. Based on the feedback from the pressure sensor, aerosol generation occurs only during a specific part of the respiratory cycle. In bench models, the PDDS Clinical has high efficiency for aerosol delivery both on and off the ventilator, with a lower respiratory tract delivery of 50-70% of the nominal dose. Currently, the PDDS Clinical is being evaluated for the treatment of ventilator-associated pneumonia with aerosolized amikacin, an aminoglycoside antibiotic. Preliminary studies in patients with ventilator-associated pneumonia found that the administration of amikacin via PDDS reduced the need for concomitant intravenous antibiotics; however, more definitive clinical studies are needed. The PDDS Clinical delivers a high percentage of the nominal dose to the lower respiratory tract, and is well suited for inhalation therapy in mechanically ventilated patients. PMID:18095891

  10. Changes in respiratory mechanics during respiratory physiotherapy in mechanically ventilated patients

    PubMed Central

    Moreira, Fernanda Callefe; Teixeira, Cassiano; Savi, Augusto; Xavier, Rogério

    2015-01-01

    Objective To evaluate the changes in ventilatory mechanics and hemodynamics that occur in patients dependent on mechanical ventilation who are subjected to a standard respiratory therapy protocol. Methods This experimental and prospective study was performed in two intensive care units, in which patients dependent on mechanical ventilation for more than 48 hours were consecutively enrolled and subjected to an established respiratory physiotherapy protocol. Ventilatory variables (dynamic lung compliance, respiratory system resistance, tidal volume, peak inspiratory pressure, respiratory rate, and oxygen saturation) and hemodynamic variables (heart rate) were measured one hour before (T-1), immediately after (T0) and one hour after (T+1) applying the respiratory physiotherapy protocol. Results During the period of data collection, 104 patients were included in the study. Regarding the ventilatory variables, an increase in dynamic lung compliance (T-1 = 52.3 ± 16.1mL/cmH2O versus T0 = 65.1 ± 19.1mL/cmH2O; p < 0.001), tidal volume (T-1 = 550 ± 134mL versus T0 = 698 ± 155mL; p < 0.001), and peripheral oxygen saturation (T-1 = 96.5 ± 2.29% versus T0 = 98.2 ± 1.62%; p < 0.001) were observed, in addition to a reduction of respiratory system resistance (T-1 = 14.2 ± 4.63cmH2O/L/s versus T0 = 11.0 ± 3.43cmH2O/L/s; p < 0.001), after applying the respiratory physiotherapy protocol. All changes were present in the assessment performed one hour (T+1) after the application of the respiratory physiotherapy protocol. Regarding the hemodynamic variables, an immediate increase in the heart rate after application of the protocol was observed, but that increase was not maintained (T-1 = 88.9 ± 18.7 bpm versus T0 = 93.7 ± 19.2bpm versus T+1 = 88.5 ± 17.1bpm; p < 0.001). Conclusion Respiratory therapy leads to immediate changes in the lung mechanics and hemodynamics of mechanical ventilation-dependent patients, and ventilatory changes are likely to remain for at least one hour

  11. Lung matrix and vascular remodeling in mechanically ventilated elastin haploinsufficient newborn mice.

    PubMed

    Hilgendorff, Anne; Parai, Kakoli; Ertsey, Robert; Navarro, Edwin; Jain, Noopur; Carandang, Francis; Peterson, Joanna; Mokres, Lucia; Milla, Carlos; Preuss, Stefanie; Alcazar, Miguel Alejandre; Khan, Suleman; Masumi, Juliet; Ferreira-Tojais, Nancy; Mujahid, Sana; Starcher, Barry; Rabinovitch, Marlene; Bland, Richard

    2015-03-01

    Elastin plays a pivotal role in lung development. We therefore queried if elastin haploinsufficient newborn mice (Eln(+/-)) would exhibit abnormal lung structure and function related to modified extracellular matrix (ECM) composition. Because mechanical ventilation (MV) has been linked to dysregulated elastic fiber formation in the newborn lung, we also asked if elastin haploinsufficiency would accentuate lung growth arrest seen after prolonged MV of neonatal mice. We studied 5-day-old wild-type (Eln(+/+)) and Eln(+/-) littermates at baseline and after MV with air for 8-24 h. Lungs of unventilated Eln(+/-) mice contained ∼50% less elastin and ∼100% more collagen-1 and lysyl oxidase compared with Eln(+/+) pups. Eln(+/-) lungs contained fewer capillaries than Eln(+/+) lungs, without discernible differences in alveolar structure. In response to MV, lung tropoelastin and elastase activity increased in Eln(+/+) neonates, whereas tropoelastin decreased and elastase activity was unchanged in Eln(+/-) mice. Fibrillin-1 protein increased in lungs of both groups during MV, more in Eln(+/-) than in Eln(+/+) pups. In both groups, MV caused capillary loss, with larger and fewer alveoli compared with unventilated controls. Respiratory system elastance, which was less in unventilated Eln(+/-) compared with Eln(+/+) mice, was similar in both groups after MV. These results suggest that elastin haploinsufficiency adversely impacts pulmonary angiogenesis and that MV dysregulates elastic fiber integrity, with further loss of lung capillaries, lung growth arrest, and impaired respiratory function in both Eln(+/+) and Eln(+/-) mice. Paucity of lung capillaries in Eln(+/-) newborns might help explain subsequent development of pulmonary hypertension previously reported in adult Eln(+/-) mice. PMID:25539853

  12. Blockage of the Ryanodine Receptor via Azumolene Does Not Prevent Mechanical Ventilation-Induced Diaphragm Atrophy

    PubMed Central

    Talbert, Erin E.; Smuder, Ashley J.; Kwon, Oh Sung; Sollanek, Kurt J.; Wiggs, Michael P.; Powers, Scott K.

    2016-01-01

    Mechanical ventilation (MV) is a life-saving intervention for patients in respiratory failure. However, prolonged MV causes the rapid development of diaphragm muscle atrophy, and diaphragmatic weakness may contribute to difficult weaning from MV. Therefore, developing a therapeutic countermeasure to protect against MV-induced diaphragmatic atrophy is important. MV-induced diaphragm atrophy is due, at least in part, to increased production of reactive oxygen species (ROS) from diaphragm mitochondria and the activation of key muscle proteases (i.e., calpain and caspase-3). In this regard, leakage of calcium through the ryanodine receptor (RyR1) in diaphragm muscle fibers during MV could result in increased mitochondrial ROS emission, protease activation, and diaphragm atrophy. Therefore, these experiments tested the hypothesis that a pharmacological blockade of the RyR1 in diaphragm fibers with azumolene (AZ) would prevent MV-induced increases in mitochondrial ROS production, protease activation, and diaphragmatic atrophy. Adult female Sprague-Dawley rats underwent 12 hours of full-support MV while receiving either AZ or vehicle. At the end of the experiment, mitochondrial ROS emission, protease activation, and fiber cross-sectional area were determined in diaphragm muscle fibers. Decreases in muscle force production following MV indicate that the diaphragm took up a sufficient quantity of AZ to block calcium release through the RyR1. However, our findings reveal that AZ treatment did not prevent the MV-induced increase in mitochondrial ROS emission or protease activation in the diaphragm. Importantly, AZ treatment did not prevent MV-induced diaphragm fiber atrophy. Thus, pharmacological inhibition of the RyR1 in diaphragm muscle fibers is not sufficient to prevent MV-induced diaphragm atrophy. PMID:26849371

  13. Lung matrix and vascular remodeling in mechanically ventilated elastin haploinsufficient newborn mice

    PubMed Central

    Hilgendorff, Anne; Parai, Kakoli; Ertsey, Robert; Navarro, Edwin; Jain, Noopur; Carandang, Francis; Peterson, Joanna; Mokres, Lucia; Milla, Carlos; Preuss, Stefanie; Alcazar, Miguel Alejandre; Khan, Suleman; Masumi, Juliet; Ferreira-Tojais, Nancy; Mujahid, Sana; Starcher, Barry; Rabinovitch, Marlene

    2014-01-01

    Elastin plays a pivotal role in lung development. We therefore queried if elastin haploinsufficient newborn mice (Eln+/−) would exhibit abnormal lung structure and function related to modified extracellular matrix (ECM) composition. Because mechanical ventilation (MV) has been linked to dysregulated elastic fiber formation in the newborn lung, we also asked if elastin haploinsufficiency would accentuate lung growth arrest seen after prolonged MV of neonatal mice. We studied 5-day-old wild-type (Eln+/+) and Eln+/− littermates at baseline and after MV with air for 8–24 h. Lungs of unventilated Eln+/− mice contained ∼50% less elastin and ∼100% more collagen-1 and lysyl oxidase compared with Eln+/+ pups. Eln+/− lungs contained fewer capillaries than Eln+/+ lungs, without discernible differences in alveolar structure. In response to MV, lung tropoelastin and elastase activity increased in Eln+/+ neonates, whereas tropoelastin decreased and elastase activity was unchanged in Eln+/− mice. Fibrillin-1 protein increased in lungs of both groups during MV, more in Eln+/− than in Eln+/+ pups. In both groups, MV caused capillary loss, with larger and fewer alveoli compared with unventilated controls. Respiratory system elastance, which was less in unventilated Eln+/− compared with Eln+/+ mice, was similar in both groups after MV. These results suggest that elastin haploinsufficiency adversely impacts pulmonary angiogenesis and that MV dysregulates elastic fiber integrity, with further loss of lung capillaries, lung growth arrest, and impaired respiratory function in both Eln+/+ and Eln+/− mice. Paucity of lung capillaries in Eln+/− newborns might help explain subsequent development of pulmonary hypertension previously reported in adult Eln+/− mice. PMID:25539853

  14. Toll-like receptor 4 knockout ameliorates neuroinflammation due to lung-brain interaction in mechanically ventilated mice.

    PubMed

    Chen, Ting; Chen, Chang; Zhang, Zongze; Zou, Yufeng; Peng, Mian; Wang, Yanlin

    2016-08-01

    Toll-like receptor 4 (TLR4) is a crucial receptor in the innate immune system, and increasing evidence supports its role in inflammation, stress, and tissue injury, including injury to the lung and brain. We aimed to investigate the effects of TLR4 on neuroinflammation due to the lung-brain interaction in mechanically ventilated mice. Male wild-type (WT) C57BL/6 and TLR4 knockout (TLR4 KO) mice were divided into three groups: (1) control group (C): spontaneous breathing; (2) anesthesia group (A): spontaneous breathing under anesthesia; and (3) mechanical ventilation group (MV): 6h of MV under anesthesia. The behavioral responses of mice were tested with fear conditioning tests. The histological changes in the lung and brain were assessed using hematoxylin-eosin (HE) staining. The level of TLR4 mRNA in tissue was measured using reverse transcription-polymerase chain reaction (RT-PCR). The levels of inflammatory cytokines were measured with an enzyme-linked immunosorbent assay (ELISA). Microgliosis, astrocytosis, and the TLR4 immunoreactivity in the hippocampus were measured by double immunofluorescence. MV mice exhibited impaired cognition, and this impairment was less severe in TLR4 KO mice than in WT mice. In WT mice, MV increased TLR4 mRNA expression in the lung and brain. MV induced mild lung injury, which was prevented in TLR4 KO mice. MV mice exhibited increased levels of inflammatory cytokines, increased microglia and astrocyte activation. Microgliosis was alleviated in TLR4 KO mice. MV mice exhibited increased TLR4 immunoreactivity, which was expressed in microglia and astrocytes. These results demonstrate that TLR4 is involved in neuroinflammation due to the lung-brain interaction and that TLR4 KO ameliorates neuroinflammation due to lung-brain interaction after prolonged MV. In addition, Administration of a TLR4 antagonist (100μg/mice) to WT mice also significantly attenuated neuroinflammation of lung-brain interaction due to prolonged MV. TLR4 antagonism

  15. Unrecognized suffering in the ICU: Addressing dyspnea in mechanically ventilated patients

    PubMed Central

    Schmidt, Matthieu; Banzett, Robert B.; Raux, Mathieu; Morélot-Panzini, Capucine; Dangers, Laurence; Similowski, Thomas; Demoule, Alexandre

    2014-01-01

    Background Intensive care unit (ICU) patients are exposed to many sources of discomfort. Although growing attention has been given to the detection and treatment of pain, very little has been given to the detection and treatment of dyspnea (defined as ‘breathing discomfort’). Discussion In this article, we review the published information on prevalence, mechanisms and potential negative impacts of dyspnea in mechanically ventilated patients. In addition, we review the most appropriate tools to detect and quantify dyspnea in ICU patients. Conclusions Growing evidence suggests that dyspnea is a frequent issue in mechanically ventilated ICU patients, is highly associated with anxiety and pain, and is improved in many patients by altering ventilator settings. Future studies are needed to better delineate the impact of dyspnea in the ICU, and to define diagnostic, monitoring and therapeutic protocols. PMID:24132382

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

    PubMed Central

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

    2014-01-01

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

  17. 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

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

    2014-01-01

    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/]) PMID:24626270

  18. Hyperpolarized 3He magnetic resonance imaging ventilation defects in asthma: relationship to airway mechanics.

    PubMed

    Leary, Del; Svenningsen, Sarah; Guo, Fumin; Bhatawadekar, Swati; Parraga, Grace; Maksym, Geoffrey N

    2016-04-01

    In patients with asthma, magnetic resonance imaging (MRI) provides direct measurements of regional ventilation heterogeneity, the etiology of which is not well-understood, nor is the relationship of ventilation abnormalities with lung mechanics. In addition, respiratory resistance and reactance are often abnormal in asthmatics and the frequency dependence of respiratory resistance is thought to reflect ventilation heterogeneity. We acquiredMRIventilation defect maps, forced expiratory volume in one-second (FEV1), and airways resistance (Raw) measurements, and used a computational airway model to explore the relationship of ventilation defect percent (VDP) with simulated measurements of respiratory system resistance (Rrs) and reactance (Xrs).MRIventilation defect maps were experimentally acquired in 25 asthmatics before, during, and after methacholine challenge and these were nonrigidly coregistered to the airway tree model. Using the model coregistered to ventilation defect maps, we narrowed proximal (9th) and distal (14th) generation airways that were spatially related to theMRIventilation defects. The relationships forVDPwith Raw measured using plethysmography (r = 0.79), and model predictions of Rrs>14(r = 0.91,P < 0.0001) and Rrs>9(r = 0.88,P < 0.0001) were significantly stronger (P = 0.005;P = 0.03, respectively) than withFEV1(r = -0.68,P = 0.0001). The slopes for the relationship ofVDPwith simulated lung mechanics measurements were different (P < 0.0001); among these, the slope for theVDP-Xrs0.2relationship was largest, suggesting thatVDPwas dominated by peripheral airway heterogeneity in these patients. In conclusion, as a first step toward understanding potential links between lung mechanics and ventilation defects, impedance predictions were made using a computational airway tree model with simulated constriction of airways related to ventilation defects measured in mild-moderate asthmatics. PMID:27053294

  19. Survival in a recent cohort of mechanically ventilated pediatric allogeneic hematopoietic stem cell transplantation recipients.

    PubMed

    van Gestel, Josephus P J; Bollen, Casper W; Bierings, Marc B; Boelens, Jaap Jan; Wulffraat, Nico M; van Vught, Adrianus J

    2008-12-01

    There is ongoing discussion whether survival improved for children requiring mechanical ventilation after hematopoietic stem cell transplantation (HSCT). We reviewed the outcomes of 150 children who received an allogeneic HSCT between January 1999 and April 2007, in a pediatric university hospital in The Netherlands. Thirty-five of the 150 patients received mechanical ventilation on 38 occasions. None of the recorded risk factors was significantly associated with the requirement of mechanical ventilation. Sixteen admissions resulted in death in the intensive care unit (ICU), giving a case fatality rate of 42% (95% confidence interval 26%-58%). ICU mortality was associated with multiorgan failure on the second day of admission and with the use of high frequency oscillatory ventilation. Patients had higher pediatric risk of mortality scores than in previous studies, reflecting higher acuity of illness on admission to the ICU. Six-month survival in patients discharged from the ICU was 82%. Compared to previous studies, we found an improvement in ICU survival and survival 6 months after ICU discharge in a recent cohort of ventilated children after allogeneic HSCT, even though our patients were more severely ill. Our results are promising, but they need to be confirmed in larger, preferably multicenter, studies. PMID:19041061

  20. Intracuff alkalized lidocaine reduces sedative/analgesic requirements for mechanically ventilated patients

    PubMed Central

    Basuni, Ahmed Sobhy

    2014-01-01

    Background: The objective of this study is to investigate the effect of intracuff alkalized lidocaine on sedative/analgesic requirements for mechanically ventilated patients and its consequence on patient-ventilator interaction. Materials and Methods: A total of 64 patients who expected to require ventilatory support for a period of more than 48 h were randomly assigned to groups S and L. In group S, the endotracheal tube (ETT) cuffs were inflated with normal saline. In group L, the ETT cuffs were inflated with lidocaine 2% and sodium bicarbonate 8.4%. The investigator and the surgical intensive care unit staff were blinded to the nature of cuff-filled solutions. Sedation was maintained with propofol and fentanyl infusions. The total requirements for propofol and fentanyl, frequency and severity of cough and number of ineffective triggering during the first 24 h of mechanical ventilation were recorded. Results: There was a significant reduction (about 30%) in the requirements for propofol and fentanyl in patients who received intracuff alkalinized lidocaine; P < 0.001. The frequency and severity of cough were significantly lower in group L compared with group S and the frequency of ineffective triggering was significantly lower in group L; P < 0.001 for both comparisons. Conclusion: Intracuff alkalized lidocaine increases ETT tolerance and hence, decreases sedatives/analgesics requirements for mechanically ventilated patients. This results in improved patient-ventilator synchronization. PMID:25422600

  1. [Complications in the use of mechanical ventilator in newborns: one year's experience].

    PubMed

    Wang, G C; Kao, H A; Hwang, F Y; Ho, M Y; Hsu, C H; Hung, H Y

    1991-01-01

    A retrospective study was undertaken of 175 patients (119 males, 56 females) admitted to the neonatal intensive care unit of Mackay Memorial Hospital during the period of July 1, 1985 to June 30, 1986 who received mechanical ventilation during their stay at the hospital. Upon reviewing the clinical histories of these patients, the complication rate of mechanical ventilation was 31.9%. The percentages of each complication were: pneumothorax 50.0%, pneumomediastinum 5.2%, pulmonary interstitial emphysema 1.7%, atelectasia 13.8%, pneumonia 13.8%, chronic lung disease 13.8%, nasopharyngeal infection 1.7%. Survival rate of these ventilated patients with or without complication was not significant statistically (69.2% vs 65.6%). However, with regard to the hospital course, cases with complication had a significantly longer duration of ventilator usage, hospital stay and oxygen usage than uncomplicated cases. In conclusion, experienced personnel are needed to supervise the use of mechanical ventilation in neonates, and a team of well-trained nurses working in the neonatal intensive care unit are essential to minimize complications. PMID:1776449

  2. [Cardiopulmonary resuscitation: risks and benefits of ventilation].

    PubMed

    Cordioli, Ricardo Luiz; Garelli, Valentina; Lyazidi, Aissam; Suppan, Laurent; Savary, Dominique; Brochard, Laurent; Richard, Jean-Christophe M

    2013-12-11

    Knowledge of the physiological mechanisms that govern cardiopulmonary interactions during cardiopulmonary resuscitation (CPR) allows to better assess risks and benefits of ventilation. Ventilation is required to maintain gas exchange, particularly when CPR is prolonged. Nevertheless, conventional ventilation (bag mask or mechanical ventilation) may be harmful when excessive or when chest compressions are interrupted. In fact large tidal volume and/or rapid respiratory rate may adversely compromise hemodynamic effects of chest compressions. In this regard, international recommendations that give the priority to chest compressions, are meaningful. Continuous flow insufflation with oxygen that generates a moderate positive airway pressure avoids any interruption of chest compressions and prevents the risk of lung injury associated with prolonged resuscitation. PMID:24416979

  3. Linking Ventilation Heterogeneity Quantified via Hyperpolarized 3He MRI to Dynamic Lung Mechanics and Airway Hyperresponsiveness

    PubMed Central

    Lui, Justin K.; Parameswaran, Harikrishnan; Albert, Mitchell S.; Lutchen, Kenneth R.

    2015-01-01

    Advancements in hyperpolarized helium-3 MRI (HP 3He-MRI) have introduced the ability to render and quantify ventilation patterns throughout the anatomic regions of the lung. The goal of this study was to establish how ventilation heterogeneity relates to the dynamic changes in mechanical lung function and airway hyperresponsiveness in asthmatic subjects. In four healthy and nine mild-to-moderate asthmatic subjects, we measured dynamic lung resistance and lung elastance from 0.1 to 8 Hz via a broadband ventilation waveform technique. We quantified ventilation heterogeneity using a recently developed coefficient of variation method from HP 3He-MRI imaging. Dynamic lung mechanics and imaging were performed at baseline, post-challenge, and after a series of five deep inspirations. AHR was measured via the concentration of agonist that elicits a 20% decrease in the subject’s forced expiratory volume in one second compared to baseline (PC20) dose. The ventilation coefficient of variation was correlated to low-frequency lung resistance (R = 0.647, P < 0.0001), the difference between high and low frequency lung resistance (R = 0.668, P < 0.0001), and low-frequency lung elastance (R = 0.547, P = 0.0003). In asthmatic subjects with PC20 values <25 mg/mL, the coefficient of variation at baseline exhibited a strong negative trend (R = -0.798, P = 0.02) to PC20 dose. Our findings were consistent with the notion of peripheral rather than central involvement of ventilation heterogeneity. Also, the degree of AHR appears to be dependent on the degree to which baseline airway constriction creates baseline ventilation heterogeneity. HP 3He-MRI imaging may be a powerful predictor of the degree of AHR and in tracking the efficacy of therapy. PMID:26569412

  4. Effect of bronchomotor tone on static mechanical properties of lung and ventilation distribution.

    PubMed

    Crawford, A B; Makowska, M; Engel, L A

    1987-12-01

    To study the relationship between bronchomotor tone, static mechanical properties of the lung, and ventilation distribution, we measured the pressure-volume (P-V) curve of the lung and several ventilatory indexes before and after intravenous atropine in eight normal subjects. The indexes of ventilation distribution were derived from multiple breath N2 washouts by a recently developed analysis (7,8). The latter not only provides a sensitive measure of overall ventilation inhomogeneity but distinguishes between the convection-dependent inhomogeneity (CDI) among larger lung units and that due to the interaction of convection and diffusion (DCDI) within the lung periphery. Atropine decreased lung elastic recoil but distensibility, as defined by the exponent (K) in the monoexponential analysis of the P-V data, was unchanged. The overall ventilation inhomogeneity increased by 37% after atropine (P less than 0.02) due to an increase in the CDI component. More importantly, there was a significant correlation between the loss of lung recoil (but not K) and each of the indexes of CDI among the subjects. There was no correlation between the changes in lung recoil and in DCDI. Our findings indicate that normal bronchomotor tone contributes to the elastic recoil of the lung. Furthermore, the tone is distributed in a way that enhances the uniformity of ventilation distribution among diffusion-independent lung units. Presumably this is achieved by minimizing interacinar intrinsic inequalities in static mechanical properties. PMID:3436864

  5. Combining ibuprofen sodium with cellulosic polymers: a deep dive into mechanisms of prolonged supersaturation.

    PubMed

    Terebetski, Jenna L; Michniak-Kohn, Bozena

    2014-11-20

    The combination of a highly soluble salt form of a drug with a polymeric precipitation inhibitor has the potential to prolong drug supersaturation even following salt disproportionation. In this study, dissolution profiles of ibuprofen sodium in the presence of various cellulosic polymers, including hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), and hydroxypropyl cellulose (HPC), were examined in order to assess degree and duration of supersaturation. In addition, the roles that the polymers played in altering drug solubility, media viscosity, physical form, and particle morphology were also assessed. A deep dive into the mechanisms of supersaturation revealed that intermolecular hydrogen bonding between ibuprofen and HPMC was driving supersaturation through nucleation inhibition and crystal growth modification. Polymer viscosity was proposed as the primary factor prolonging supersaturation of ibuprofen in the presence of MC, while mechanisms other than hydrogen bonding were likely to be attributed to supersaturation with the most hydrophobic polymer evaluated, HPC. Overall, the study suggested that induction of intermolecular interactions between ibuprofen and HPMC were more effective at inhibiting nucleation and maintaining prolonged supersaturation than physical modulation of solution properties, such as viscosity. PMID:25219860

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

    PubMed Central

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

    2016-01-01

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

  7. 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

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

    2013-01-01

    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. PMID:24213081

  8. The effect of dexmedetomidine on agitation during weaning of mechanical ventilation in critically ill patients.

    PubMed

    Shehabi, Y; Nakae, H; Hammond, N; Bass, F; Nicholson, L; Chen, J

    2010-01-01

    Ventilated patients receiving opioids and/or benzodiazepines are at high risk of developing agitation, particularly upon weaning towards extubation. This is often associated with an increased intubation time and length of stay in the intensive care unit and may cause long-term morbidity. Anxiety, fear and agitation are amongst the most common non-pulmonary causes of failure to liberate from mechanical ventilation. This prospective, open-label observational study examined 28 ventilated adult patients in the intensive care unit (30 episodes) requiring opioids and/or sedatives for >24 hours, who developed agitation and/or delirium upon weaning from sedation and failed to achieve successful extubation with conventional management. Patients were ventilated for a median (interquartile range) of 115 [87 to 263] hours prior to enrolment. Dexmedetomidine infusion was commenced at 0.4 microg/kg/hour for two hours, after which concurrent sedative therapy was preferentially weaned and titrated to obtain target Motor Activity Assessment Score score of 2 to 4. The median (range) maximum dose and infusion time of dexmedetomidine was 0.7 microg/kg/hour (0.4 to 1.0) and 62 hours (24 to 252) respectively. The number of episodes at target Motor Activity Assessment Score score at zero, six and 12 hours after commencement of dexmedetomidine were 7/30 (23.3%), 28/30 (93.3%) and 26/30 (86.7%), respectively (P < 0.001 for 6 and 12 vs. 0 hours). Excluding unrelated clinical deterioration, 22 episodes (73.3%) achieved successful weaning from ventilation with a median (interquartile range) ventilation time of 70 (28 to 96) hours after dexmedetomidine infusion. Dexmedetomidine achieved rapid resolution of agitation and facilitated ventilatory weaning after failure of conventional therapy. Its role as first-line therapy in ventilated, agitated patients warrants further investigation. PMID:20191782

  9. Impact of Ventilatory Modes on the Breathing Variability in Mechanically Ventilated Infants

    PubMed Central

    Baudin, Florent; Wu, Hau-Tieng; Bordessoule, Alice; Beck, Jennifer; Jouvet, Philippe; Frasch, Martin G.; Emeriaud, Guillaume

    2014-01-01

    Objectives: Reduction of breathing variability is associated with adverse outcome. During mechanical ventilation, the variability of ventilatory pressure is dependent on the ventilatory mode. During neurally adjusted ventilatory assist (NAVA), the support is proportional to electrical activity of the diaphragm (EAdi), which reflects the respiratory center output. The variability of EAdi is, therefore, translated into a similar variability in pressures. Contrastingly, conventional ventilatory modes deliver less variable pressures. The impact of the mode on the patient’s own respiratory drive is less clear. This study aims to compare the impact of NAVA, pressure-controlled ventilation (PCV), and pressure support ventilation (PSV) on the respiratory drive patterns in infants. We hypothesized that on NAVA, EAdi variability resembles most of the endogenous respiratory drive pattern seen in a control group. Methods: Electrical activity of the diaphragm was continuously recorded in 10 infants ventilated successively on NAVA (5 h), PCV (30 min), and PSV (30 min). During the last 10 min of each period, the EAdi variability pattern was assessed using non-rhythmic to rhythmic (NRR) index. These variability profiles were compared to the pattern of a control group of 11 spontaneously breathing and non-intubated infants. Results: In control infants, NRR was higher as compared to mechanically ventilated infants (p < 0.001), and NRR pattern was relatively stable over time. While the temporal stability of NRR was similar in NAVA and controls, the NRR profile was less stable during PCV. PSV exhibited an intermediary pattern. Perspectives: Mechanical ventilation impacts the breathing variability in infants. NAVA produces EAdi pattern resembling most that of control infants. NRR can be used to characterize respiratory variability in infants. Larger prospective studies are necessary to understand the differential impact of the ventilatory modes on the cardio

  10. Mechanical ventilation and sepsis induce skeletal muscle catabolism in neonatal pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. Clinical study on VATS combined mechanical ventilation treatment of ARDS secondary to severe chest trauma

    PubMed Central

    Qi, Yongjun

    2016-01-01

    The aim of the study was to investigate the clinical effects of microinvasive video-assisted thoracoscopic surgery (VATS) combined with mechanical ventilation in the treatment of acute respiratory distress syndrome (ARDS) secondary to severe chest trauma. A total of 62 patients with ARDS secondary to severe chest trauma were divided into the observation and control groups. The patients in the observation groups were treated with VATS combined with early mechanical ventilation while patients in the control group were treated using routine open thoracotomy combined with early mechanical ventilation. Compared to the controls, the survival rate of the observation group was significantly higher. The average operation time of the observation group was significantly shorter than that of the control group, and the incidence of complications in the perioperative period of the observation group was significantly lower than that of the control group (p<0.05). The average application time of the observation group was significantly shorter than that of the control group, and the incidence of ventilator-associated complications was significantly lower than that of the control group (p<0.05). In conclusion, a reasonable understanding of the indications and contraindications of VATS, combined with early mechanical treatment significantly improved the success rate of the treatment of ARDS patients secondary to severe chest trauma and reduced the complications. PMID:27446317

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. [THE DIAGNOSTIC AND THERAPEUTIC BRONCHOSCOPY IN CARDIAC PATIENTS UNDERGOING MECHANICAL VENTILATION IN THE POSTOPERATIVE PERIOD].

    PubMed

    Titova, I V; Khrustaleva, M V; Eremenko, A A; Babaev, M A

    2016-01-01

    The review presents an analysis of domestic and foreign literature on the use of bronchoscopy in patients with obstructive respiratory failure in the ICU. Separately considered the issue of additional research when performing bronchoscopy and create an algorithmfor the application of diagnostic and therapeutic bronchoscopy in cardiac surgical patients undergoing mechanical ventilation. PMID:27192859

  14. Surgical procedure affects physiological parameters in rat myocardial ischemia: need for mechanical ventilation.

    PubMed

    Horstick, G; Berg, O; Heimann, A; Darius, H; Lehr, H A; Bhakdi, S; Kempski, O; Meyer, J

    1999-02-01

    Several surgical approaches are being used to induce myocardial ischemia in rats. The present study investigated two different operative procedures in spontaneously breathing and mechanically ventilated rats under sham conditions. A snare around the left coronary artery (LCA) was achieved without occlusion. Left lateral thoracotomy was performed in spontaneously breathing and mechanically ventilated rats (tidal volume 8 ml/kg) with a respiratory rate of 90 strokes/min at different levels of O2 supplementation (room air and 30, 40, and 90% O2). All animals were observed for 60 min after thoracotomy. Rats operated with exteriorization of the heart through left lateral thoracotomy while breathing spontaneously developed severe hypoxia and hypercapnia despite an intrathoracic operation time of <1 min. Arterial O2 content decreased from 18.7 +/- 0.5 to 3.3 +/- 0.9 vol%. Lactate increased from 1.2 +/- 0.1 to 5.2 +/- 0.3 mmol/l. Significant signs of ischemia were seen in the electrocardiogram up to 60 min. Mechanically ventilated animals exhibited a spectrum ranging from hypoxia (room air) to hyperoxia (90% O2). In order not to jeopardize findings in experimental myocardial ischemia-reperfusion injury models, stable physiological parameters can be achieved in mechanically ventilated rats at an O2 application of 30-40% at 90 strokes/min. PMID:9950847

  15. Mechanical ventilation induces myokine expression and catabolism in peripheral skeletal muscle in pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Endotoxin (LPS)-induced sepsis increases circulating cytokines which have been associated with skeletal muscle catabolism. During critical illness, it has been postulated that muscle wasting associated with mechanical ventilation (MV) occurs due to inactivity. We hypothesize that MV and sepsis promo...

  16. [The effect of non-invasive mechanical ventilation in postoperative respiratory failure].

    PubMed

    Ozyılmaz, Ezgi; Kaya, Akın

    2012-01-01

    Postoperative respiratory failure is related with the highest mortality and morbidity among all perioperative complications. The most common underlying mechanism of postoperative respiratory failure is the development of atelectasis. Anaesthesia, medications which cause respiratory depression, high FiO2 use, postoperative pain and disruption of muscle forces due to surgery leads to decrease in functional residual capacity and results in atelectasis formation. Atelectasis causes severe hypoxemia due to ventilation, perfusion mismatch, shunt and increased peripheral vascular resistance. Intrathoracic positive pressure is an effective therapeutic option in both prevention and treatment of atelectasis. Non-invasive mechanical ventilation is related with a lower mortality and morbidity rate due to lack of any potential complication risks of endotracheal intubation. Non-invasive mechanical ventilation can be applied as prophylactic or curative. Both of these techniques are related with lower reintubation rates, nosocomial infections, duration of hospitalization and mortality in patients with postoperative respiratory failure. The differences of this therapy from standard application and potential complications should be well known in order to improve prognosis in these group of patients. The primary aim of this review is to underline the pathogenesis of postoperative respiratory failure. The secondary aim is to clarify the optimum method, effect and complications of non-invasive mechanical ventilation therapy under the light of the studies which was performed in specific patient groups. PMID:22779943

  17. The Effects of Guided Imagery on Patients Being Weaned from Mechanical Ventilation

    PubMed Central

    Spiva, LeeAnna; Hart, Patricia L.; Gallagher, Erin; McVay, Frank; Garcia, Melida; Malley, Karen; Kadner, Marsha; Segars, Angela; Brakovich, Betsy; Horton, Sonja Y.; Smith, Novlette

    2015-01-01

    The study purpose was to assess the effects of guided imagery on sedation levels, sedative and analgesic volume consumption, and physiological responses of patients being weaned from mechanical ventilation. Forty-two patients were selected from two community acute care hospitals. One hospital served as the comparison group and provided routine care (no intervention) while the other hospital provided the guided imagery intervention. The intervention included two sessions, each lasting 60 minutes, offered during morning weaning trials from mechanical ventilation. Measurements were recorded in groups at baseline and 30- and 60-minute intervals and included vital signs and Richmond Agitation-Sedation Scale (RASS) score. Sedative and analgesic medication volume consumption were recorded 24 hours prior to and after the intervention. The guided imagery group had significantly improved RASS scores and reduced sedative and analgesic volume consumption. During the second session, oxygen saturation levels significantly improved compared to the comparison group. Guided imagery group had 4.88 less days requiring mechanical ventilation and 1.4 reduction in hospital length of stay compared to the comparison group. Guided imagery may be complementary and alternative medicine (CAM) intervention to provide during mechanical ventilation weaning trials. PMID:26640501

  18. Biophysical determinants of alveolar epithelial plasma membrane wounding associated with mechanical ventilation

    PubMed Central

    Hussein, Omar; Walters, Bruce; Stroetz, Randolph; Valencia, Paul; McCall, Deborah

    2013-01-01

    Mechanical ventilation may cause harm by straining lungs at a time they are particularly prone to injury from deforming stress. The objective of this study was to define the relative contributions of alveolar overdistension and cyclic recruitment and “collapse” of unstable lung units to membrane wounding of alveolar epithelial cells. We measured the interactive effects of tidal volume (VT), transpulmonary pressure (PTP), and of airspace liquid on the number of alveolar epithelial cells with plasma membrane wounds in ex vivo mechanically ventilated rat lungs. Plasma membrane integrity was assessed by propidium iodide (PI) exclusion in confocal images of subpleural alveoli. Cyclic inflations of normal lungs from zero end-expiratory pressure to 40 cmH2O produced VT values of 56.9 ± 3.1 ml/kg and were associated with 0.12 ± 0.12 PI-positive cells/alveolus. A preceding tracheal instillation of normal saline (3 ml) reduced VT to 49.1 ± 6 ml/kg but was associated with a significantly greater number of wounded alveolar epithelial cells (0.52 ± 0.16 cells/alveolus; P < 0.01). Mechanical ventilation of completely saline-filled lungs with saline (VT = 52 ml/kg) to pressures between 10 and 15 cmH2O was associated with the least number of wounded epithelial cells (0.02 ± 0.02 cells/alveolus; P < 0.01). In mechanically ventilated, partially saline-filled lungs, the number of wounded cells increased substantially with VT, but, once VT was accounted for, wounding was independent of maximal PTP. We found that interfacial stress associated with the generation and destruction of liquid bridges in airspaces is the primary biophysical cell injury mechanism in mechanically ventilated lungs. PMID:23997173

  19. Biophysical determinants of alveolar epithelial plasma membrane wounding associated with mechanical ventilation.

    PubMed

    Hussein, Omar; Walters, Bruce; Stroetz, Randolph; Valencia, Paul; McCall, Deborah; Hubmayr, Rolf D

    2013-10-01

    Mechanical ventilation may cause harm by straining lungs at a time they are particularly prone to injury from deforming stress. The objective of this study was to define the relative contributions of alveolar overdistension and cyclic recruitment and "collapse" of unstable lung units to membrane wounding of alveolar epithelial cells. We measured the interactive effects of tidal volume (VT), transpulmonary pressure (PTP), and of airspace liquid on the number of alveolar epithelial cells with plasma membrane wounds in ex vivo mechanically ventilated rat lungs. Plasma membrane integrity was assessed by propidium iodide (PI) exclusion in confocal images of subpleural alveoli. Cyclic inflations of normal lungs from zero end-expiratory pressure to 40 cmH2O produced VT values of 56.9 ± 3.1 ml/kg and were associated with 0.12 ± 0.12 PI-positive cells/alveolus. A preceding tracheal instillation of normal saline (3 ml) reduced VT to 49.1 ± 6 ml/kg but was associated with a significantly greater number of wounded alveolar epithelial cells (0.52 ± 0.16 cells/alveolus; P < 0.01). Mechanical ventilation of completely saline-filled lungs with saline (VT = 52 ml/kg) to pressures between 10 and 15 cmH2O was associated with the least number of wounded epithelial cells (0.02 ± 0.02 cells/alveolus; P < 0.01). In mechanically ventilated, partially saline-filled lungs, the number of wounded cells increased substantially with VT, but, once VT was accounted for, wounding was independent of maximal PTP. We found that interfacial stress associated with the generation and destruction of liquid bridges in airspaces is the primary biophysical cell injury mechanism in mechanically ventilated lungs. PMID:23997173

  20. [Non-invasive mechanical ventilation therapy in patients with heart failure].

    PubMed

    Dursunoğlu, Dursun; Dursunoğlu, Neşe

    2012-05-01

    Non-invasive mechanical ventilation (NIMV) therapy in patients with acute heart failure (HF) improves left ventricular functions via decreasing left ventricular afterload and reduces intubation rate and short-term mortality. In patients with chronic HF, NIMV therapy eliminates central and obstructive apneas and Cheyne-Stokes respiration, and improves morbidity. There are essentially three modes of NIMV that are used in the treatment of HF: Continuous positive airway pressure (CPAP), bilevel positive airway pressure (BIPAP) and adaptive servo-ventilation (ASV). Hereby, NIMV therapy in patients with acute and chronic HF is reviewed as well as methods, indications, effectiveness and complications. PMID:22381927

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

    PubMed

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

    2015-11-01

    Non-invasive ventilation (NIV) is a method of ventilatory support that is increasing in importance day by day in the management of postoperative respiratory failure. Its role in the prevention and treatment of atelectasis is particularly important in the in the period after thoracic and abdominal surgeries. Similarly, in the transplanted patient, NIV can shorten the time of invasive mechanical ventilation, reducing the risk of infectious complications in these high-risk patients. It has been performed A systematic review of the literature has been performed, including examining the technical, clinical experiences and recommendations concerning the application of NIV in the postoperative period. PMID:25892605

  2. Influence of different degrees of head elevation on respiratory mechanics in mechanically ventilated patients

    PubMed Central

    Martinez, Bruno Prata; Marques, Thaís Improta; Santos, Daniel Reis; Salgado, Vanessa Silva; Nepomuceno Júnior, Balbino Rivail; Alves, Giovani Assunção de Azevedo; Gomes Neto, Mansueto; Forgiarini Junior, Luiz Alberto

    2015-01-01

    Objective The positioning of a patient in bed may directly affect their respiratory mechanics. The objective of this study was to evaluate the respiratory mechanics of mechanically ventilated patients positioned with different head angles hospitalized in an intensive care unit. Methods This was a prospective physiological study in which static and dynamic compliance, resistive airway pressure, and peripheral oxygen saturation were measured with the head at four different positions (0° = P1, 30° = P2, 45° = P3, and 60° = P4). Repeated-measures analysis of variance (ANOVA) with a Bonferroni post-test and Friedman analysis were used to compare the values obtained at the different positions. Results A comparison of the 35 evaluated patients revealed that the resistive airway pressure values in the 0° position were higher than those obtained when patients were positioned at greater angles. The elastic pressure analysis revealed that the 60° position produced the highest value relative to the other positions. Regarding static compliance, a reduction in values was observed from the 0° position to the 60° position. The dynamic compliance analysis revealed that the 30° angle produced the greatest value compared to the other positions. The peripheral oxygen saturation showed little variation, with the highest value obtained at the 0° position. Conclusion The highest dynamic compliance value was observed at the 30° position, and the highest oxygenation value was observed at the 0° position. PMID:26761472

  3. Institutional care for long-term mechanical ventilation in Canada: A national survey

    PubMed Central

    Rose, Louise; McKim, Douglas; Katz, Sherri; Leasa, David; Nonoyama, Mika; Pedersen, Cheryl; Avendano, Monica; Goldstein, Roger

    2014-01-01

    INTRODUCTION: No national Canadian data define resource requirements and care delivery for ventilator-assisted individuals (VAIs) requiring long-term institutional care. Such data will assist in planning health care services to this population. OBJECTIVE: To describe institutional and patient characteristics, prevalence, equipment used, care elements and admission barriers for VAIs requiring long-term institutional care. METHODS: Centres were identified from a national inventory and snowball referrals. The survey weblink was provided from December 2012 to April 2013. Weekly reminders were sent for six weeks. RESULTS: The response rate was 84% (54 of 64), with 44 adult and 10 pediatric centres providing data for 428 VAIs (301 invasive ventilation; 127 noninvasive ventilation [NIV]), equivalent to 1.3 VAIs per 100,000 population. An additional 106 VAIs were on wait lists in 18 centres. More VAIs with progressive neuromuscular disease received invasive ventilation than NIV (P<0.001); more VAIs with chronic obstructive pulmonary disease (P<0.001), obesity hypoventilation syndrome (P<0.001) and central hypoventilation syndrome (P=0.02) required NIV. All centres used positive pressure ventilators, 21% diaphragmatic pacing, 15% negative pressure and 13% phrenic nerve stimulation. Most centres used lung volume recruitment (55%), manually (71%) and mechanically assisted cough (55%). Lack of beds and provincial funding were common admission barriers. CONCLUSIONS: Variable models and care practices exist for institutionalized care of Canadian VAIs. Patient prevalence was 1.3 per 100,000 Canadians. PMID:25184510

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

    PubMed Central

    Bach, J. R.

    1992-01-01

    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 PMID:1586868

  5. Fluid flow and particle transport in mechanically ventilated airways. Part I. Fluid flow structures.

    PubMed

    Van Rhein, Timothy; Alzahrany, Mohammed; Banerjee, Arindam; Salzman, Gary

    2016-07-01

    A large eddy simulation-based computational study of fluid flow and particle transport in upper tracheobronchial airways is carried out to investigate the effect of ventilation parameters on pulmonary fluid flow. Respiratory waveforms commonly used by commercial mechanical ventilators are used to study the effect of ventilation parameters and ventilation circuit on pulmonary fluid dynamics. A companion paper (Alzahrany et al. in Med Biol Eng Comput, 2014) reports our findings on the effect of the ventilation parameters and circuit on particle transport and aerosolized drug delivery. The endotracheal tube (ETT) was found to be an important geometric feature and resulted in a fluid jet that caused an increase in turbulence and created a recirculation zone with high wall shear stress in the main bronchi. Stronger turbulence was found in lower airways than would be found under normal breathing conditions due to the presence of the jet caused by the ETT. The pressure-controlled sinusoidal waveform induced the lowest wall shear stress on the airways wall. PMID:26563199

  6. Noninvasive mechanical ventilation in chronic obstructive pulmonary disease and in acute cardiogenic pulmonary edema.

    PubMed

    Rialp Cervera, G; del Castillo Blanco, A; Pérez Aizcorreta, O; Parra Morais, L

    2014-03-01

    Noninvasive ventilation (NIV) with conventional therapy improves the outcome of patients with acute respiratory failure due to hypercapnic decompensation of chronic obstructive pulmonary disease (COPD) or acute cardiogenic pulmonary edema (ACPE). This review summarizes the main effects of NIV in these pathologies. In COPD, NIV improves gas exchange and symptoms, reducing the need for endotracheal intubation, hospital mortality and hospital stay compared with conventional oxygen therapy. NIV may also avoid reintubation and may decrease the length of invasive mechanical ventilation. In ACPE, NIV accelerates the remission of symptoms and the normalization of blood gas parameters, reduces the need for endotracheal intubation, and is associated with a trend towards lesser mortality, without increasing the incidence of myocardial infarction. The ventilation modality used in ACPE does not affect the patient prognosis. PMID:23158869

  7. [Non-invasive mechanical ventilation in the treatment of acute heart failure].

    PubMed

    Alfonso Megido, Joaquín; González Franco, Alvaro

    2014-03-01

    When acute heart failure progresses and there is acute cardiogenic pulmonary edema, routine therapeutic measures should be accompanied by other measures that help to correct oxygenation of the patient. The final and most drastic step is mechanical ventilation. Non-invasive ventilation has been developed in the last few years as a method that attempts to improve oxygenation without the need for intubation, thus, in theory, reducing morbidity and mortality in these patients. The present article describes the controversies surrounding the results of this technique and discusses its indications. The article also discusses how to start non-invasive ventilation in patients with acute pulmonary edema from a practical point of view. PMID:24930085

  8. Impact of mechanical ventilation on the pathophysiology of progressive acute lung injury.

    PubMed

    Nieman, Gary F; Gatto, Louis A; Habashi, Nader M

    2015-12-01

    The earliest description of what is now known as the acute respiratory distress syndrome (ARDS) was a highly lethal double pneumonia. Ashbaugh and colleagues (Ashbaugh DG, Bigelow DB, Petty TL, Levine BE Lancet 2: 319-323, 1967) correctly identified the disease as ARDS in 1967. Their initial study showing the positive effect of mechanical ventilation with positive end-expiratory pressure (PEEP) on ARDS mortality was dampened when it was discovered that improperly used mechanical ventilation can cause a secondary ventilator-induced lung injury (VILI), thereby greatly exacerbating ARDS mortality. This Synthesis Report will review the pathophysiology of ARDS and VILI from a mechanical stress-strain perspective. Although inflammation is also an important component of VILI pathology, it is secondary to the mechanical damage caused by excessive strain. The mechanical breath will be deconstructed to show that multiple parameters that comprise the breath-airway pressure, flows, volumes, and the duration during which they are applied to each breath-are critical to lung injury and protection. Specifically, the mechanisms by which a properly set mechanical breath can reduce the development of excessive fluid flux and pulmonary edema, which are a hallmark of ARDS pathology, are reviewed. Using our knowledge of how multiple parameters in the mechanical breath affect lung physiology, the optimal combination of pressures, volumes, flows, and durations that should offer maximum lung protection are postulated. PMID:26472873

  9. Sustained Inflation at Birth Did Not Alter Lung Injury from Mechanical Ventilation in Surfactant-Treated Fetal Lambs

    PubMed Central

    Hillman, Noah H.; Kemp, Matthew W.; Miura, Yuichiro; Kallapur, Suhas G.; Jobe, Alan H.

    2014-01-01

    Background Sustained inflations (SI) are used with the initiation of ventilation at birth to rapidly recruit functional residual capacity and may decrease lung injury and the need for mechanical ventilation in preterm infants. However, a 20 second SI in surfactant-deficient preterm lambs caused an acute phase injury response without decreasing lung injury from subsequent mechanical ventilation. Hypothesis A 20 second SI at birth will decrease lung injury from mechanical ventilation in surfactant-treated preterm fetal lambs. Methods The head and chest of fetal sheep at 126±1 day GA were exteriorized, with tracheostomy and removal of fetal lung fluid prior to treatment with surfactant (300 mg in 15 ml saline). Fetal lambs were randomized to one of four 15 minute interventions: 1) PEEP 8 cmH2O; 2) 20 sec SI at 40 cmH2O, then PEEP 8 cmH2O; 3) mechanical ventilation with 7 ml/kg tidal volume; or 4) 20 sec SI then mechanical ventilation at 7 ml/kg. Fetal lambs remained on placental support for the intervention and for 30 min after the intervention. Results SI recruited a mean volume of 6.8±0.8 mL/kg. SI did not alter respiratory physiology during mechanical ventilation. Heat shock protein (HSP) 70, HSP60, and total protein in lung fluid similarly increased in both ventilation groups. Modest pro-inflammatory cytokine and acute phase responses, with or without SI, were similar with ventilation. SI alone did not increase markers of injury. Conclusion In surfactant treated fetal lambs, a 20 sec SI did not alter ventilation physiology or markers of lung injury from mechanical ventilation. PMID:25419969

  10. Brief mechanical ventilation causes differential epithelial repair along the airways of fetal, preterm lambs.

    PubMed

    Deptula, Nicole; Royse, Emily; Kemp, Matthew W; Miura, Yuichiro; Kallapur, Suhas G; Jobe, Alan H; Hillman, Noah H

    2016-08-01

    Mechanical ventilation of preterm lambs causes lung inflammation and injury to the airway epithelium, which is repaired by 15 days after ventilation. In mice, activated basal cells (p63+, KRT14+, KRT8+) initiate injury repair to the trachea, whereas club cells coordinate distal airway repair. In both human and sheep, basal cells line the pseudostratified airways to the distal bronchioles with club cells only present in terminal bronchioles. Mechanical ventilation causes airway epithelial injury that is repaired through basal cell activation in the fetal lung. Ewes at 123 ± 1 day gestational age had the head and chest of the fetus exteriorized and tracheostomy placed. With placental circulation intact, fetal lambs were mechanically ventilated with up to 15 ml/kg for 15 min with 95% N2/5% CO2 Fetal lambs were returned to the uterus for up to 24 h. The trachea, left mainstem bronchi, and peripheral lung were evaluated for epithelial injury and cellular response consistent with repair. Peripheral lung tissue had inflammation, pro-inflammatory cytokine production, epithelial growth factor receptor ligand upregulation, increased p63 expression, and proliferation of pro-SPB, TTF-1 positive club cells. In bronchi, KRT14 and KRT8 mRNA increased without increases in Notch pathway mRNA or proliferation. In trachea, mRNA increased for Notch ligands, SAM pointed domain-containing Ets transcription factor and mucin 5B, but not for basal cell markers. A brief period of mechanical ventilation causes differential epithelial activation between trachea, bronchi, and peripheral lung. The repair mechanisms identified in adult mice occur at different levels of airway branching in fetal sheep with basal and club cell activation. PMID:27343193

  11. Sampling and analyzing alveolar exhaled breath condensate in mechanically ventilated patients: a feasibility study.

    PubMed

    Vaschetto, Rosanna; Corradi, Massimo; Goldoni, Matteo; Cancelliere, Laura; Pulvirenti, Simone; Fazzini, Ugo; Capuzzi, Fabio; Longhini, Federico; Mutti, Antonio; Della Corte, Francesco; Navalesi, Paolo

    2015-12-01

    Recent studies in spontaneously breathing subjects indicate the possibility of obtaining the alveolar fraction of exhaled breath condensate (aEBC). In critically ill mechanically ventilated patients, in whom microbial colonization of the upper airways is constant, collection of aEBC could considerably add to the ability of monitoring alveolar inflammation. We designed this study to test the feasibility of collecting aEBC in mechanically ventilated critically ill patients through a dedicated apparatus, i.e. a CO2 valve combined with a condenser placed in the expiratory limb of the ventilator circuit. We also aimed to assess the adequacy of the samples obtained by measuring different markers of oxidative stress and inflammation. We enrolled 40 mechanically ventilated patients, 20 with and 20 without acute respiratory distress syndrome (ARDS). Measurements of respiratory mechanics, gas exchange and hemodynamics were obtained with a standard ventilator circuit after 30 min of aEBC collection and after inserting the dedicated collecting apparatus. Data showed that intrinsic positive end-expiratory pressure, peak and plateau pressure, static compliance and airway resistance (Raw) were similar before and after adding the collecting apparatus in both ARDS and controls. Similarly, gas exchange and hemodynamic variables did not change and 30 min collection provided a median aEBC volume of 2.100 and 2.300 ml for ARDS and controls, respectively. aEBC pH showed a trend toward a slight reduction in the ARDS group of patients, as opposed to controls (7.83 (7.62-8.03) versus 7.98 (7.87-8.12), respectively, p  =  0.055)). H2O2 was higher in patients with ARDS, compared to controls (0.09 (0.06-0.12) μM versus 0.03 (0.01-0.09) μM, p  =  0.043), while no difference was found in proteins content, 8-isoprostane, 4-hydroxy-2-nonhenal. In conclusion, we demonstrate, in patients receiving controlled mechanical ventilation, that aEBC collection is feasible without

  12. A new nasal cavity nursing methods application in patients with mechanical ventilation

    PubMed Central

    Wei, Liuqing; Qin, Gang; Yang, Xining; Hu, Meichun; Jiang, Fufu; Lai, Tianwei

    2013-01-01

    Objective: To compare different nasal cavity nursing methods on mechanically ventilated patients. Methods: According to acute physiology and chronic health evaluation (APACHEII), 615 cases of mechanically ventilated patients were divided into group A, group B and group C by stratified random method. Traditional oral nursing plus aspirating secretions from oral cavity and nasal cavity q6h were done in group A. Based on methods in group A, normal saline was used for cleaning nasal cavity in group B. Besides the methods in group A, atomizing nasal cleansing a6h was also used in group C. Incidence rate of Ventilator-Associated Pneumonia (VAP) and APACHE II scores after administrating were compared. The correlation between APACHE II score and outcomes was analyzed by Spearman-rank correlation. Results: In group A, incidence of VAP was 36.76%, group B was 30.24%, group C was 20.38%, and the difference was statistically significant. APACHE II scores in group C were significantly lower compared with group A and B. APACHE II score was negatively correlated with clinical outcomes. Conclusions: For mechanically ventilated patients, nasal nursing can’t be ignored and the new atomizing nasal cleaning is an effective method for VAP prevention. PMID:24353671

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

    PubMed Central

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

    2014-01-01

    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

  14. A novel simulator for mechanical ventilation in newborns: MEchatronic REspiratory System SImulator for Neonatal Applications.

    PubMed

    Baldoli, Ilaria; Cuttano, Armando; Scaramuzzo, Rosa T; Tognarelli, Selene; Ciantelli, Massimiliano; Cecchi, Francesca; Gentile, Marzia; Sigali, Emilio; Laschi, Cecilia; Ghirri, Paolo; Menciassi, Arianna; Dario, Paolo; Boldrini, Antonio

    2015-08-01

    Respiratory problems are among the main causes of mortality for preterm newborns with pulmonary diseases; mechanical ventilation provides standard care, but long-term complications are still largely reported. In this framework, continuous medical education is mandatory to correctly manage assistance devices. However, commercially available neonatal respiratory simulators are rarely suitable for representing anatomical and physiological conditions; a step toward high-fidelity simulation, therefore, is essential for nurses and neonatologists to acquire the practice needed without any risk. An innovative multi-compartmental infant respirator simulator based on a five-lobe model was developed to reproduce different physio-pathological conditions in infants and to simulate many different kinds of clinical scenarios. The work consisted of three phases: (1) a theoretical study and modeling phase, (2) a prototyping phase, and (3) testing of the simulation software during training courses. The neonatal pulmonary simulator produced allows the replication and evaluation of different mechanical ventilation modalities in infants suffering from many different kinds of respiratory physio-pathological conditions. In particular, the system provides variable compliances for each lobe in an independent manner and different resistance levels for the airway branches; moreover, it allows the trainer to simulate both autonomous and mechanically assisted respiratory cycles in newborns. The developed and tested simulator is a significant contribution to the field of medical simulation in neonatology, as it makes it possible to choose the best ventilation strategy and to perform fully aware management of ventilation parameters. PMID:26238790

  15. Invasive Mechanical Ventilation in California Over 2000–2009: Implications for Emergency Medicine

    PubMed Central

    Mudumbai, Seshadri C.; Barr, Juli; Scott, Jennifer; Mariano, Edward R.; Bertaccini, Edward; Nguyen, Hieu; Memtsoudis, Stavros G.; Cason, Brian; Phibbs, Ciaran S.; Wagner, Todd

    2015-01-01

    Introduction Patients who require invasive mechanical ventilation (IMV) often represent a sequence of care between the emergency department (ED) and intensive care unit (ICU). Despite being the most populous state, little information exists to define patterns of IMV use within the state of California. Methods We examined data from the masked Patient Discharge Database of California’s Office of Statewide Health Planning and Development from 2000–2009. Adult patients who received IMV during their stay were identified using the International Classification of Diseases 9th Revision and Clinical Modification procedure codes (96.70, 96.71, 96.72). Patients were divided into age strata (18–34yr, 35–64yr, and >65yr). Using descriptive statistics and regression analyses, for IMV discharges during the study period, we quantified the number of ED vs. non-ED based admissions; changes in patient characteristics and clinical outcome; evaluated the marginal costs for IMV; determined predictors for prolonged acute mechanical ventilation (PAMV, i.e. IMV>96hr); and projected the number of IMV discharges and ED-based admissions by year 2020. Results There were 696,634 IMV discharges available for analysis. From 2000–2009, IMV discharges increased by 2.8%/year: n=60,933 (293/100,000 persons) in 2000 to n=79,868 (328/100,000 persons) in 2009. While ED-based admissions grew by 3.8%/year, non-ED-based admissions remained stable (0%). During 2000–2009, fastest growth was noted for 1) the 35–64 year age strata; 2) Hispanics; 3) patients with non-Medicare public insurance; and 4) patients requiring PAMV. Average total patient cost-adjusted charges per hospital discharge increased by 29% from 2000 (from $42,528 to $60,215 in 2014 dollars) along with increases in the number of patients discharged to home and skilled nursing facilities. Higher marginal costs were noted for younger patients (ages 18–34yr), non-whites, and publicly insured patients. Some of the strongest

  16. Achilles tendon mechanical properties after both prolonged continuous running and prolonged intermittent shuttle running in cricket batting.

    PubMed

    Houghton, Laurence; Dawson, Brian; Rubenson, Jonas

    2013-08-01

    Effects of prolonged running on Achilles tendon properties were assessed after a 60 min treadmill run and 140 min intermittent shuttle running (simulated cricket batting innings). Before and after exercise, 11 participants performed ramp-up plantar flexions to maximum-voluntary-contraction before gradual relaxation. Muscle-tendon-junction displacement was measured with ultrasonography. Tendon force was estimated using dynamometry and a musculoskeletal model. Gradients of the ramp-up force-displacement curves fitted between 0-40% and 50-90% of the preexercise maximal force determined stiffness in the low- and high-force-range, respectively. Hysteresis was determined using the ramp-up and relaxation force-displacement curves and elastic energy storage from the area under the ramp-up curve. In simulated batting, correlations between tendon properties and shuttle times were also assessed. After both protocols, Achilles tendon force decreased (4% to 5%, P < .050), but there were no changes in stiffness, hysteresis, or elastic energy. In simulated batting, Achilles tendon force and stiffness were both correlated to mean turn and mean sprint times (r = -0.719 to -0.830, P < .050). Neither protocol resulted in fatigue-related changes in tendon properties, but higher tendon stiffness and plantar flexion force were related to faster turn and sprint times, possibly by improving force transmission and control of movement when decelerating and accelerating. PMID:22923384

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

    PubMed Central

    2014-01-01

    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). PMID:24885921

  18. Alveolar recruitment maneuver in mechanic ventilation pediatric intensive care unit children.

    PubMed

    Neves, Valéria Cabral; Koliski, Adriana; Giraldi, Dinarte José

    2009-12-01

    Recent changes were introduced in acute hypoxemic respiratory failure children ventilation methods. There are evidences that less aggressive ventilation strategies can improve severe pulmonary injury survival. Experimental trials evidenced a relationship between inappropriate ventilatory measures and delayed acute pulmonary injury improvement, or even worsening. From this, a protective ventilatory measure arises in combination with alveolar recruitment maneuver. This association is believed in clinical practice to determine importantly reduced morbidity and mortality as well as reduced mechanic ventilation-induced injuries. It is indicated for acute lung injury patients, generally from pneumonia or sepsis, with severe hypoxemia. Its main contraindications are homodynamic instability, pneumothorax and intracranial hypertension. Experimental trials showed beneficial maneuver effects on both oxygenation and alveolar collapse. Adult studies showed improved pulmonary function with hypoxemia reversion. In children, the maneuver lead to significant inspired oxygen fraction and alveolar collapse reductions, less oxygen dependency, improved pulmonary complacency, and reduced bronchopulmonary dysplasia. However, studies in children are limited. Additional investigation is warranted on this matter, and its clinical application evidence. A literature review was conducted based on textbooks and MEDLINE, Pubmed, Cochrane library, SciELO, and Ovid databases, from 1998 to 2009, both in Portuguese and English. Publications on alveolar recruitment maneuver both in adults and children, review articles, experimental and clinical trials were included using the key words: protective ventilatory strategy, alveolar recruitment maneuver, pediatrics and mechanic ventilation. PMID:25307339

  19. Microbial composition and antibiotic resistance of biofilms recovered from endotracheal tubes of mechanically ventilated patients.

    PubMed

    Vandecandelaere, Ilse; Coenye, Tom

    2015-01-01

    In critically ill patients, breathing is impaired and mechanical ventilation, using an endotracheal tube (ET) connected to a ventilator, is necessary. Although mechanical ventilation is a life-saving procedure, it is not without risk. Because of several reasons, a biofilm often forms at the distal end of the ET and this biofilm is a persistent source of bacteria which can infect the lungs, causing ventilator-associated pneumonia (VAP). There is a link between the microbial flora of ET biofilms and the microorganisms involved in the onset of VAP. Culture dependent and independent techniques were already used to identify the microbial flora of ET biofilms and also, the antibiotic resistance of microorganisms obtained from ET biofilms was determined. The ESKAPE pathogens play a dominant role in the onset of VAP and these organisms were frequently identified in ET biofilms. Also, antibiotic resistant microorganisms were frequently present in ET biofilms. Members of the normal oral flora were also identified in ET biofilms but it is thought that these organisms initiate ET biofilm formation and are not directly involved in the development of VAP. PMID:25366226

  20. Measurement of pressure-volume curves in patients on mechanical ventilation: methods and significance

    PubMed Central

    Lu, Qin; Rouby, Jean-Jacques

    2000-01-01

    Physiological background concerning mechanics of the respiratory system, techniques of measurement and clinical implications of pressure-volume curve measurement in mechanically ventilated patients are discussed in the present review. The significance of lower and upper inflection points, the assessment of positive end-expiratory pressure (PEEP)-induced alveolar recruitment and overdistension and rationale for optimizing ventilatory settings in patients with acute lung injury are presented. Evidence suggests that the continuous flow method is a simple and reliable technique for measuring pressure-volume curves at the bedside. In patients with acute respiratory failure, determination of lower and upper inflection points and measurement of respiratory compliance should become a part of the routine assessment of lung injury severity, allowing a bedside monitoring of the evolution of the lung disease and an optimization of mechanical ventilation. PMID:11094498

  1. Using heart-lung interactions to assess fluid responsiveness during mechanical ventilation

    PubMed Central

    Michard, Frédéric; Teboul, Jean-Louis

    2000-01-01

    According to the Frank-Starling relationship, a patient is a 'responder' to volume expansion only if both ventricles are preload dependent. Mechanical ventilation induces cyclic changes in left ventricular (LV) stroke volume, which are mainly related to the expiratory decrease in LV preload due to the inspiratory decrease in right ventricular (RV) filling and ejection. In the present review, we detail the mechanisms by which mechanical ventilation should result in greater cyclic changes in LV stroke volume when both ventricles are 'preload dependent'. We also address recent clinical data demonstrating that respiratory changes in arterial pulse (or systolic) pressure and in Doppler aortic velocity (as surrogates of respiratory changes in LV stroke volume) can be used to detect biventricular preload dependence, and hence fluid responsiveness in critically ill patients. PMID:11094507

  2. The predicting ability of serum potassium to assess the duration of mechanical ventilation in critically ill patients

    PubMed Central

    Javdan, Zahra; Talakoub, Reihanak; Honarmand, Azim; Golparvar, Mohammad; Farsani, Enayatolah Yadollahi

    2015-01-01

    Background: No previous study has been done to evaluate the admission serum potassium level as a predictor of morbidity or need for mechanical ventilation. The aim of this study is to determine the predictive ability of serum potassium on admission, in critically ill trauma patients, and to evaluate the relation of the potassium level to organ failure, length of stay, ventilator need, and duration of mechanical ventilation. Materials and Methods: A prospective, observational study was done on 100 patients >16 years old, admitted to the Medical-Surgical Intensive Care Units (ICU), for over one year. Patients were classified into Group A: Patients who required equal or less than five days of mechanical ventilation and Group B: Patients who required more than five days of mechanical ventilation. The total serum potassium concentrations were measured and the Sequential Organ Failure Assessment (SOFA) score was recorded at the time of admission to the ICU, when connected to the ventilator, and then at the time of weaning from the ventilator. Results: There was no significant difference between the Serum K concentrations between the two groups, on admission. However, there were significant difference between the Serum K concentrations at times of receiving and weaning from mechanical ventilation (MV) between the two groups. We found the best cut-off point of 3.45 for serum potassium concentration, to predict the need for longer duration of MV. Conclusion: Development of hypokalemia during an ICU stay is associated with the need for mechanical ventilation. Monitoring of the serum potassium levels may be a good prognostic factor for the requirement of mechanical ventilation. PMID:26322281

  3. Quantum mechanics in non-inertial reference frames: Time-dependent rotations and loop prolongations

    SciTech Connect

    Klink, W.H.; Wickramasekara, S.

    2013-09-15

    This is the fourth in a series of papers on developing a formulation of quantum mechanics in non-inertial reference frames. This formulation is grounded in a class of unitary cocycle representations of what we have called the Galilean line group, the generalization of the Galilei group to include transformations amongst non-inertial reference frames. These representations show that in quantum mechanics, just as the case in classical mechanics, the transformations to accelerating reference frames give rise to fictitious forces. In previous work, we have shown that there exist representations of the Galilean line group that uphold the non-relativistic equivalence principle as well as representations that violate the equivalence principle. In these previous studies, the focus was on linear accelerations. In this paper, we undertake an extension of the formulation to include rotational accelerations. We show that the incorporation of rotational accelerations requires a class of loop prolongations of the Galilean line group and their unitary cocycle representations. We recover the centrifugal and Coriolis force effects from these loop representations. Loops are more general than groups in that their multiplication law need not be associative. Hence, our broad theoretical claim is that a Galilean quantum theory that holds in arbitrary non-inertial reference frames requires going beyond groups and group representations, the well-established framework for implementing symmetry transformations in quantum mechanics. -- Highlights: •A formulation of Galilean quantum mechanics in non-inertial reference frames is presented. •The Galilei group is generalized to infinite dimensional Galilean line group. •Loop prolongations of Galilean line group contain central extensions of Galilei group. •Unitary representations of the loops are constructed. •These representations lead to terms in the Hamiltonian corresponding to fictitious forces, including centrifugal and Coriolis

  4. The efficacy of noninvasive mechanical ventilation on nocturnal hypoxaemia in Duchenne's muscular dystrophy.

    PubMed

    Fanfulla, F; Berardinelli, A; Gualtieri, G; Zoia, M C; Ottolini, A; Vianello, A; Lanzi, G; Cerveri, I

    1998-02-01

    The aim of this 2 yr follow-up study was to evaluate the efficacy of nocturnal noninvasive mechanical ventilation in a group of 10 Duchenne's muscular dystrophy (DMD) patients who desaturated during the night but had normal daytime blood gases: mean (range) age 18.3 (15-22) yrs; mean (SD) vital capacity (VC) 752.5 (460-1,308) mL; mean time in bed (TIB) with arterial oxygen saturation (Sa,O2) < 90% 22.8% of total TIB (range: 16.6-32.0); mean arterial oxygen tension (Pa,O2) 10.3 (9.3-11.7) kPa (78 (70.0-87.8) mmHg); mean arterial carbon dioxide tension (Pa,CO2) 5.9 (4.8-6.5) kPa (44.3 (36.3-48.5) mmHg). All the patients were noninvasively ventilated during the night with a bilevel positive pressure ventilation (BiPAP) devise in spontaneous mode in order to correct the episodes of nocturnal desaturation. Nocturnal Sa,O2 values normalized during nocturnal noninvasive mechanical ventilation, and daytime sleep-disordered breathing disappeared, for the entire study period. No statistically significant differences were observed between baseline and follow-up daytime blood gas values, although a slight increase in Pa,O2 was found. During the follow-up, VC declined at a rate of 79.1 +/- 25 mL.yr-1, less than that generally reported in the past in untreated patients in the same age range. In conclusion, our data suggest that patients with advanced Duchenne's muscular dystrophy with pronounced nocturnal desaturation, not fulfilling criteria for imperative ventilation, could be successfully treated with "elective" nocturnal ventilation with immediate benefits consequent to the correction of the nocturnal blood gas anomalies and with long-term benefits related to the preservation of residual respiratory function, delay of development of chronic hypercapnia and thus the requirement for imperative mechanical ventilation. PMID:9632901

  5. Mechanical ventilation and volutrauma: study in vivo of a healthy pig model.

    PubMed

    Pastore, Camilla V; Pirrone, Federica; Mazzola, Silvia; Rizzi, Manuela; Viola, Manuela; Sironi, Giuseppe; Albertini, Mariangela

    2011-01-01

    Mechanical ventilation is essential in intensive care units. However, it may itself induce lung injury. Current studies are based on rodents, using exceptionally large tidal volumes for very short periods, often after a "priming" pulmonary insult. Our study deepens a clinically relevant large animal model, closely resembling human physiology and the ventilator setting used in clinic settings. Our aim was to evaluate the pathophysiological mechanisms involved in alveolo/capillary barrier damage due to mechanical stress in healthy subjects. We randomly divided 18 pigs (sedated with medetomidine/tiletamine-zolazepam and anesthetised with thiopental sodium) into three groups (n=6): two were mechanically ventilated (tidal volume of 8 or 20 ml/kg), the third breathed spontaneously for 4 hours, then animals were sacrificed (thiopental overdose). We analyzed every 30' hemogasanalysis and the main circulatory and respiratory parameters. Matrix gelatinase expression was evaluated on bronchoalveolar lavage fluid after surgery and before euthanasia. On autoptic samples we performed zymographic analysis of lung, kidney and liver tissues and histological examination of lung. Results evidenced that high Vt evoked profound alterations of lung mechanics and structure, although low Vt strategy was not devoid of side effects, too. Unexpectedly, also animals that were spontaneously breathing showed a worsening of the respiratory functions. PMID:22688908

  6. Analysis of the mechanisms of expiratory asynchrony in pressure support ventilation: a mathematical approach.

    PubMed

    Yamada, Y; Du, H L

    2000-06-01

    A mathematical model was developed to analyze the mechanisms of expiratory asynchrony during pressure support ventilation (PSV). Solving the model revealed several results. 1) Ratio of the flow at the end of patient neural inspiration to peak inspiratory flow (VTI/V(peak)) during PSV is determined by the ratio of time constant of the respiratory system (tau) to patient neural inspiratory time (TI) and the ratio of the set pressure support (Pps) level to maximal inspiratory muscle pressure (Pmus max). 2) VTI/V(peak) is affected more by tau/TI than by Pps/Pmus max. VTI/V(peak) increases in a sigmoidal relationship to tau/TI. An increase in Pps/Pmus max slightly shifts the VTI/V(peak)-tau/TI curve to the right, i.e., VTI/V(peak) becomes lower as Pps/Pmus max increases at the same tau/TI. 3) Under the selected adult respiratory mechanics, VTI/V(peak) ranges from 1 to 85% and has an excellent linear correlation with tau/TI. 4) In mechanical ventilators, single fixed levels of the flow termination criterion will always have chances of both synchronized termination and asynchronized termination, depending on patient mechanics. An increase in tau/TI causes more delayed and less premature termination opportunities. An increase in Pps/Pmus max narrows the synchronized zone, making inspiratory termination predisposed to be in asynchrony. Increasing the expiratory trigger sensitivity of a ventilator shifts the synchronized zone to the right, causing less delayed and more premature termination. Automation of expiratory trigger sensitivity in future mechanical ventilators may also be possible. In conclusion, our model provides a useful tool to analyze the mechanisms of expiratory asynchrony in PSV. PMID:10846029

  7. [Percutaneous tracheostomy in the ventilated patient].

    PubMed

    Añón, J M; Araujo, J B; Escuela, M P; González-Higueras, E

    2014-04-01

    The medical indications of tracheostomy comprise the alleviation of upper airway obstruction; the prevention of laryngeal and upper airway damage due to prolonged translaryngeal intubation in patients subjected to prolonged mechanical ventilation; and the facilitation of airway access for the removal of secretions. Since 1985, percutaneous tracheostomy (PT) has gained widespread acceptance as a method for creating a surgical airway in patients requiring long-term mechanical ventilation. Since then, several comparative trials of PT and surgical tracheostomy have been conducted, and new techniques for PT have been developed. The use of percutaneous dilatation techniques under bronchoscopic control are now increasingly popular throughout the world. Tracheostomy should be performed as soon as the need for prolonged intubation is identified. However a validated model for the prediction of prolonged mechanical ventilation is not available, and the timing of tracheostomy should be individualized. The present review analyzes the state of the art of PT in mechanically ventilated patients--this being regarded by many as the technique of choice in performing tracheostomy in critically ill patients. PMID:23347906

  8. Adjunct therapies during mechanical ventilation: airway clearance techniques, therapeutic aerosols, and gases.

    PubMed

    Kallet, Richard H

    2013-06-01

    Mechanically ventilated patients in respiratory failure often require adjunct therapies to address special needs such as inhaled drug delivery to alleviate airway obstruction, treat pulmonary infection, or stabilize gas exchange, or therapies that enhance pulmonary hygiene. These therapies generally are supportive in nature rather than curative. Currently, most lack high-level evidence supporting their routine use. This overview describes the rationale and examines the evidence supporting adjunctive therapies during mechanical ventilation. Both mechanistic and clinical research suggests that intrapulmonary percussive ventilation may enhance pulmonary secretion mobilization and might reverse atelectasis. However, its impact on outcomes such ICU stay is uncertain. The most crucial issue is whether aerosolized antibiotics should be used to treat ventilator-associated pneumonia, particularly when caused by multi-drug resistant pathogens. There is encouraging evidence from several studies supporting its use, at least in individual cases of pneumonia non-responsive to systemic antibiotic therapy. Inhaled pulmonary vasodilators provide at least short-term improvement in oxygenation and may be useful in stabilizing pulmonary gas exchange in complex management situations. Small uncontrolled studies suggest aerosolized heparin with N-acetylcysteine might break down pulmonary casts and relieve airway obstruction in patients with severe inhalation injury. Similar low-level evidence suggests that heliox is effective in reducing airway pressure and improving ventilation in various forms of lower airway obstruction. These therapies generally are supportive and may facilitate patient management. However, because they have not been shown to improve patient outcomes, it behooves clinicians to use these therapies parsimoniously and to monitor their effectiveness carefully. PMID:23709200

  9. Injury and repair in the very immature lung following brief mechanical ventilation.

    PubMed

    Brew, Nadine; Hooper, Stuart B; Allison, Beth J; Wallace, Megan J; Harding, Richard

    2011-12-01

    Mechanical ventilation (MV) of very premature infants contributes to lung injury and bronchopulmonary dysplasia (BPD), the effects of which can be long-lasting. Little is currently known about the ability of the very immature lung to recover from ventilator-induced lung injury. Our objective was to determine the ability of the injured very immature lung to repair in the absence of continued ventilation and to identify potential mechanisms. At 125 days gestational age (days GA, 0.85 of term), fetal sheep were partially exposed by hysterotomy under anesthesia and aseptic conditions; they were intubated and ventilated for 2 h with an injurious MV protocol and then returned to the uterus to continue development. Necropsy was performed at either 1 day (short-term group, 126 days GA, n = 6) or 15 days (long-term group, 140 days GA, n = 5) after MV; controls were unventilated (n = 7-8). At 1 day after MV, lungs displayed signs of injury, including hemorrhage, disorganized elastin and collagen deposition in the distal airspaces, altered morphology, significantly reduced secondary septal crest density, and decreased airspace. Bronchioles had thickened epithelium with evidence of injury and sloughing. Relative mRNA levels of early response genes (connective tissue growth factor, cysteine-rich 61, and early growth response-1) and proinflammatory cytokines [interleukins (IL)-1β, IL-6, IL-8, tumor necrosis factor-α, and transforming growth factor-β] were not different between groups 1 day after MV. At 15 days after MV, lung structure was normal with no evidence of injury. We conclude that 2 h of MV induces severe injury in the very immature lung and that these lungs have the capacity to repair spontaneously in the absence of further ventilation. PMID:21890511

  10. Neonatal total liquid ventilation: is low-frequency forced oscillation technique suitable for respiratory mechanics assessment?

    PubMed

    Bossé, Dominick; Beaulieu, Alexandre; Avoine, Olivier; Micheau, Philippe; Praud, Jean-Paul; Walti, Hervé

    2010-08-01

    This study aimed to implement low-frequency forced oscillation technique (LFFOT) in neonatal total liquid ventilation (TLV) and to provide the first insight into respiratory impedance under this new modality of ventilation. Thirteen newborn lambs, weighing 2.5 + or - 0.4 kg (mean + or - SD), were premedicated, intubated, anesthetized, and then placed under TLV using a specially design liquid ventilator and a perfluorocarbon. The respiratory mechanics measurements protocol was started immediately after TLV initiation. Three blocks of measurements were first performed: one during initial respiratory system adaptation to TLV, followed by two other series during steady-state conditions. Lambs were then divided into two groups before undergoing another three blocks of measurements: the first group received a 10-min intravenous infusion of salbutamol (1.5 microg x kg(-1) x min(-1)) after continuous infusion of methacholine (9 microg x kg(-1) x min(-1)), while the second group of lambs was chest strapped. Respiratory impedance was measured using serial single-frequency tests at frequencies ranging between 0.05 and 2 Hz and then fitted with a constant-phase model. Harmonic test signals of 0.2 Hz were also launched every 10 min throughout the measurement protocol. Airway resistance and inertance were starkly increased in TLV compared with gas ventilation, with a resonant frequency < or = 1.2 Hz. Resistance of 0.2 Hz and reactance were sensitive to bronchoconstriction and dilation, as well as during compliance reduction. We report successful implementation of LFFOT to neonatal TLV and present the first insight into respiratory impedance under this new modality of ventilation. We show that LFFOT is an effective tool to track respiratory mechanics under TLV. PMID:20538848

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

    PubMed

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

    1998-09-01

    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

  12. Effect of percutaneous endoscopic gastrostomy on gastro-esophageal reflux in mechanically-ventilated patients

    PubMed Central

    Douzinas, Emmanuel E; Tsapalos, Andreas; Dimitrakopoulos, Antonios; Diamanti-Kandarakis, Evanthia; Rapidis, Alexandros D; Roussos, Charis

    2006-01-01

    AIM: To investigate the effect of percutaneous endoscopic gastrostomy (PEG) on gastroesophageal reflux (GER) in mechanically-ventilated patients. METHODS : In a prospective, randomized, controlled study 36 patients with recurrent or persistent ventilator-associated pneumonia (VAP) and GER > 6% were divided into PEG group (n = 16) or non-PEG group (n  = 20). Another 11 ventilated patients without reflux (GER < 3%) served as control group. Esophageal pH-metry was performed by the “pull through” method at baseline, 2 and 7 d after PEG. Patients were strictly followed up for semi-recumbent position and control of gastric nutrient residue. RESULTS: A significant decrease of median (range) reflux was observed in PEG group from 7.8 (6.2 - 15.6) at baseline to 2.7 (0 - 10.4) on d 7 post-gastrostomy (P < 0.01), while the reflux increased from 9 (6.2 - 22) to 10.8 (6.3 - 36.6) (P < 0.01) in non-PEG group. A significant correlation between GER (%) and the stay of nasogastric tube was detected (r = 0.56, P < 0.01). CONCLUSION: Gastrostomy when combined with semi-recumbent position and absence of nutrient gastric residue reduces the gastroesophageal reflux in ventilated patients. PMID:16440428

  13. The role of endocrine mechanisms in ventilator-associated lung injury in critically ill patients.

    PubMed

    Penesova, A; Galusova, A; Vigas, M; Vlcek, M; Imrich, R; Majek, M

    2012-07-01

    The critically ill subjects are represented by a heterogeneous group of patients suffering from a life-threatening event of different origin, e.g. trauma, cardiopulmonary failure, surgery or sepsis. The majority of these patients are dependent on the artificial lung ventilation, which means a life-saving chance for them. However, the artificial lung ventilation may trigger ventilation-associated lung injury (VALI). The mechanical ventilation at higher volumes (volutrauma) and pressure (barotrauma) can cause histological changes in the lungs including impairments in the gap and adherens junctions and desmosomes. The injured lung epithelium may lead to an impairment of the surfactant production and function, and this may not only contribute to the pathophysiology of VALI but also to acute respiratory distress syndrome. Other components of VALI are atelectrauma and toxic effects of the oxygen. Collectively, all these effects may result in a lung inflammation associated with a subsequent profibrotic changes, endothelial dysfunction, and activation of the local and systemic endocrine responses such as the renin-angiotensin system (RAS). The present review is aimed to describe some of the pathophysiologic aspects of VALI providing a basis for novel therapeutic strategies in the critically ill patients. PMID:22808908

  14. A Comparative Data-Based Modeling Study on Respiratory CO2 Gas Exchange during Mechanical Ventilation

    PubMed Central

    Kim, Chang-Sei; Ansermino, J. Mark; Hahn, Jin-Oh

    2016-01-01

    The goal of this study is to derive a minimally complex but credible model of respiratory CO2 gas exchange that may be used in systematic design and pilot testing of closed-loop end-tidal CO2 controllers in mechanical ventilation. We first derived a candidate model that captures the essential mechanisms involved in the respiratory CO2 gas exchange process. Then, we simplified the candidate model to derive two lower-order candidate models. We compared these candidate models for predictive capability and reliability using experimental data collected from 25 pediatric subjects undergoing dynamically varying mechanical ventilation during surgical procedures. A two-compartment model equipped with transport delay to account for CO2 delivery between the lungs and the tissues showed modest but statistically significant improvement in predictive capability over the same model without transport delay. Aggregating the lungs and the tissues into a single compartment further degraded the predictive fidelity of the model. In addition, the model equipped with transport delay demonstrated superior reliability to the one without transport delay. Further, the respiratory parameters derived from the model equipped with transport delay, but not the one without transport delay, were physiologically plausible. The results suggest that gas transport between the lungs and the tissues must be taken into account to accurately reproduce the respiratory CO2 gas exchange process under conditions of wide-ranging and dynamically varying mechanical ventilation conditions. PMID:26870728

  15. When should sedation or neuromuscular blockade be used during mechanical ventilation?

    PubMed

    Bennett, Suzanne; Hurford, William E

    2011-02-01

    Sedation has become an important part of critical care practice in minimizing patient discomfort and agitation during mechanical ventilation. Pain, anxiety, and delirium form a triad of factors that can lead to agitation. Achieving and maintaining an optimal level of comfort and safety in the intensive care unit plays an essential part in caring for critically ill patients. Sedatives, opioids, and neuromuscular blocking agents are commonly used in the intensive care unit. The goal of therapy should be directed toward a specific indication, not simply to provide restraint. Standard rating scales and unit-based guidelines facilitate the proper use of sedation and neuromuscular blocking agents. The goal of sedation is a calm, comfortable patient who can easily be aroused and who can tolerate mechanical ventilation and procedures required for their care. PMID:21333177

  16. Mechanical properties of Skylab thermal shield materials after prolonged ultraviolet irradiation

    NASA Technical Reports Server (NTRS)

    Haehner, C. L.; Staugaitis, C. L.

    1974-01-01

    In response to an emergency request, the mechanical properties of two complex laminate materials, used as thermal shields on the Skylab spacecraft, were investigated. Concern over the prolonged use of these materials in the space environment prompted this investigation. Shields made of both of these materials, popularly called the parasol and the sail types, were taken to the Skylab spacecraft by the original Skylab astronauts. Both were used to restore thermal control after the original control surfaces were damaged during launch. During the tests the tensile properties were measured at anticipated service temperature and after prolonged exposure to increasing degrees of ultraviolet radiation at intensities approaching two solar constants. Some samples received exposures equivalent to 2,350 hours. The performance and degradation of the two materials are presented in terms of orientation, vacuum, and degree of irradiation. In general, the 75-micron (3-mil) parasol laminate showed a decrease in tensile properties as a function of exposure time, while the 200-micron (8-mil) sail laminate was little affected by exposure to the ultraviolet radiation.

  17. Intrapulmonary haematoma complicating mechanical ventilation in patients with chronic obstructive pulmonary disease.

    PubMed

    Bonmarchand, G; Lefebvre, E; Lerebours-Pigeonnière, G; Genevois, A; Massari, P; Leroy, J

    1988-01-01

    Intrapulmonary haematomas occurred during mechanical ventilation of two patients with advanced chronic obstructive pulmonary disease and bullous dystrophy. In both cases, the haematomas were revealed by blood-stained aspirates, a fall in haemoglobin level, and the appearance of radiological opacities. Haematoma occurrence in the area of a bulla which recently has rapidly increased in size, suggests that the haematoma is due to the rupture of stretched vessels embedded in the wall of the bulla. PMID:3379188

  18. Development and Validation of a Quality of Life Questionnaire for Mechanically Ventilated Intensive Care Unit Patients

    PubMed Central

    Pandian, Vinciya; Thompson, Carol B.; Feller-Kopman, David J.; Mirski, Marek A.

    2014-01-01

    Objective To develop and validate a new instrument for measuring health-related quality of life in mechanically ventilated patients in the intensive care unit (ICU). Design Expert panel consensus and a prospective longitudinal survey. Setting Urban, academic, tertiary care medical center. Patients One hundred and fifteen awake, mechanically ventilated, ICU patients who either received a tracheostomy or remained endotracheally intubated. Interventions A new quality of life instrument was developed and validated by using pilot study data; informal interviews of patients, families, and nurses; expert panel consensus; and item analyses. The new instrument was used to measure quality of life at three time points (5 days, 10 days, and 15 days post-intubation). Measurements and Main Results A new 12-item quality of life questionnaire for mechanically ventilated patients was developed. Patients’ responses to the quality of life questionnaire revealed moderate to high correlations with EuroQol-5D scores (r = −0.4 to −0.9) and the EuroQol Visual Analog Scale (r = 0.6 to 0.9) across the three times, and a moderate correlation with the Sequential Organ Failure Assessment tool (r = 0.5) at 10 days post-intubation. Cronbach’s alpha ranged from 0.80 to 0.94 across the three times. The quality of life instrument was responsive to changes in treatment modalities (tracheostomy vs. no tracheostomy; and early vs. late tracheostomy demarcated by 10 days of intubation). Exploratory factor analysis revealed that this instrument was unidimensional in nature. Conclusions The new quality of life questionnaire is valid and can reliably measure QOL in mechanically ventilated ICU patients. It may provide clinicians with an accurate assessment of patients’ quality of life and facilitate optimal decision-making regarding patients’ ICU plan of care. PMID:25072754

  19. Ventilator-driven xenon ventilation studies

    SciTech Connect

    Chilcoat, R.T.; Thomas, F.D.; Gerson, J.I.

    1984-07-01

    A modification of a common commerical Xe-133 ventilation device is described for mechanically assisted ventilation imaging. The patient's standard ventilator serves as the power source controlling the ventilator rate and volume during the xenon study, but the gases in the two systems are not intermixed. This avoids contamination of the ventilator with radioactive xenon. Supplemental oxygen and positive end-expiratory pressure (PEEP) are provided if needed. The system can be converted quickly for conventional studies with spontaneous respiration.

  20. Molecular mechanisms that could contribute to prolonged effectiveness of PDE5 inhibitors to improve erectile function.

    PubMed

    Francis, S H; Morris, G Z; Corbin, J D

    2008-01-01

    Cyclic guanosine monophosphate (cGMP) in penile vascular smooth muscle cells (VSMC) plays a key role in promoting penile erection. Phosphodiesterase-5 (PDE5) in VSMC breaks down cGMP to counter this effect. Sildenafil (Viagra), vardenafil (Levitra) and tadalafil (Cialis), treatments for erectile dysfunction, inhibit PDE5 action. Many men with erectile dysfunction have improved erectile function after plasma inhibitor concentration falls below therapeutic levels. Maximum effect plus onset and duration of action of inhibitor determines its efficacy. The rate and extent of cellular drug accumulation and efflux of drug from smooth muscle cells plus persistence of drug effects in these cell impact these parameters. We propose possible molecular mechanisms that could account for prolonged action of PDE5 inhibitors including (1) persistence of biochemical effects after inhibitor is cleared from cells, and (2) retention of drug in VSMC beyond plasma clearance. PMID:18418391

  1. Histopathologic pulmonary changes from mechanical ventilation at high peak airway pressures.

    PubMed

    Tsuno, K; Miura, K; Takeya, M; Kolobow, T; Morioka, T

    1991-05-01

    We investigated the histopathologic pulmonary changes induced by mechanical pulmonary ventilation (MV) with a high peak airway pressure and a large tidal volume in healthy baby pigs. Eleven animals were mechanically ventilated at a peak inspiratory pressure (PIP) of 40 cm H2O, a respiratory rate (RR) of 20 min-1, a positive end-expiratory pressure (PEEP) of 3 to 5 cm H2O, and an FIO2 of 0.4. High airway pressure MV was terminated in 22 +/- 11 h because of severe hypoxemia in the animals. Five of the baby pigs were killed for gross and light microscope studies. The pulmonary changes consisted of alveolar hemorrhage, alveolar neutrophil infiltration, alveolar macrophage and type II pneumocyte proliferation, interstitial congestion and thickening, interstitial lymphocyte infiltration, emphysematous change, and hyaline membrane formation. Those lesions were similar to that seen in the early stage of the adult respiratory distress syndrome (ARDS). The remaining six animals were treated for 3 to 6 days with conventional respiratory care with appropriate ventilator settings. Prominent organized alveolar exudate in addition to lesions was also found in the five animals. These findings were indistinguishable from the clinical late stage of ARDS. Six control animals were mechanically ventilated at a PIP of less than 18 cm H2O, a RR of 20 min-1, a PEEP of 3 to 5 cm H2O, and an FIO2 of 0.4 for 48 h. They showed no notable changes in lung functions and histopathologic findings. Aggressive MV with a high PIP is often applied to patients with respiratory distress to attain adequate pulmonary gas exchange.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2024823

  2. Kinetic profiling of in vivo lung cellular inflammatory responses to mechanical ventilation

    PubMed Central

    Woods, Samantha J.; Waite, Alicia A. C.; O'Dea, Kieran P.; Halford, Paul; Takata, Masao

    2015-01-01

    Mechanical ventilation, through overdistension of the lung, induces substantial inflammation that is thought to increase mortality among critically ill patients. The mechanotransduction processes involved in converting lung distension into inflammation during this ventilator-induced lung injury (VILI) remain unclear, although many cell types have been shown to be involved in its pathogenesis. This study aimed to identify the profile of in vivo lung cellular activation that occurs during the initiation of VILI. This was achieved using a flow cytometry-based method to quantify the phosphorylation of several markers (p38, ERK1/2, MAPK-activated protein kinase 2, and NF-κB) of inflammatory pathway activation within individual cell types. Anesthetized C57BL/6 mice were ventilated with low (7 ml/kg), intermediate (30 ml/kg), or high (40 ml/kg) tidal volumes for 1, 5, or 15 min followed by immediate fixing and processing of the lungs. Surprisingly, the pulmonary endothelium was the cell type most responsive to in vivo high-tidal-volume ventilation, demonstrating activation within just 1 min, followed by the alveolar epithelium. Alveolar macrophages were the slowest to respond, although they still demonstrated activation within 5 min. This order of activation was specific to VILI, since intratracheal lipopolysaccharide induced a very different pattern. These results suggest that alveolar macrophages may become activated via a secondary mechanism that occurs subsequent to activation of the parenchyma and that the lung cellular activation mechanism may be different between VILI and lipopolysaccharide. Our data also demonstrate that even very short periods of high stretch can promote inflammatory activation, and, importantly, this injury may be immediately manifested within the pulmonary vasculature. PMID:25770178

  3. [Collateral ventilation].

    PubMed

    Voshaar, Th H

    2008-06-01

    The phenomenon of collateral ventilation is defined as ventilation of alveolar structures through passages or channels that bypass the normal airways. Such bypassing structures can be interalveolar, bronchiole-alveolar, interbronchiole, and interlobar. Collateral ventilation structures seem to be prominent in human lungs with trapped air and emphysema. In healthy human lungs normally no relevant collateral ventilation can be detected. In emphysematic lungs the ventilation through collateral channels can probably improve gas exchange mechanisms. The phenomenon of collateral ventilation explains several clinical observations in human lungs such as the absence of atalectasis following complete bronchial obstruction, e. g. after foreign body aspiration or tumour. The various results after bronchoscopic implantation of one-way endobronchial valves as a new technique for treating emphysema can also be explained by collateral ventilation. Understanding collateral ventilation is of high importance for clinicians, those working in the field of physiology of emphysema in human lungs and may be central to planning new bronchoscopic techniques for treating emphysema. The paper offers an overview of history, physiology and the relevance for lung volume reduction methods. Moreover, a new imaging technique to demonstrate collateral ventilation in vivo is described. PMID:18535980

  4. Quantum mechanics in non-inertial reference frames: Time-dependent rotations and loop prolongations

    NASA Astrophysics Data System (ADS)

    Klink, W. H.; Wickramasekara, S.

    2013-09-01

    This is the fourth in a series of papers on developing a formulation of quantum mechanics in non-inertial reference frames. This formulation is grounded in a class of unitary cocycle representations of what we have called the Galilean line group, the generalization of the Galilei group to include transformations amongst non-inertial reference frames. These representations show that in quantum mechanics, just as the case in classical mechanics, the transformations to accelerating reference frames give rise to fictitious forces. In previous work, we have shown that there exist representations of the Galilean line group that uphold the non-relativistic equivalence principle as well as representations that violate the equivalence principle. In these previous studies, the focus was on linear accelerations. In this paper, we undertake an extension of the formulation to include rotational accelerations. We show that the incorporation of rotational accelerations requires a class of loop prolongations of the Galilean line group and their unitary cocycle representations. We recover the centrifugal and Coriolis force effects from these loop representations. Loops are more general than groups in that their multiplication law need not be associative. Hence, our broad theoretical claim is that a Galilean quantum theory that holds in arbitrary non-inertial reference frames requires going beyond groups and group representations, the well-established framework for implementing symmetry transformations in quantum mechanics.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed Central

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

    2014-01-01

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

  7. Gastro-oesophageal reflux in mechanically ventilated patients: effects of an oesophageal balloon.

    PubMed

    Orozco-Levi, M; Félez, M; Martínez-Miralles, E; Solsona, J F; Blanco, M L; Broquetas, J M; Torres, A

    2003-08-01

    Gastro-oesophageal reflux (GOR) and bronchoaspiration of gastric content are risk factors linked with ventilator-associated pneumonia. This study was aimed at evaluating the effect of a nasogastric tube (NGT) incorporating a low-pressure oesophageal balloon on GOR and bronchoaspiration in patients receiving mechanical ventilation. Fourteen patients were studied in a semi-recumbent position for 2 consecutive days. Inflation or deflation of the oesophageal balloon was randomised. Samples of blood, gastric content, and oropharyngeal and bronchial secretions were taken every 2 h over a period of 8 h. A radioactively labelled nutritional solution was continuously administered through the NGT. The magnitude of both the GOR and bronchoaspiration was measured by radioactivity counting of oropharyngeal and bronchial secretion samples, respectively. Inflation of the oesophageal balloon resulted in a significant decrease of both GOR and bronchoaspiration of gastric content. This protective effect was statistically significant from 4 h following inflation throughout the duration of the study. This study demonstrates that an inflated oesophageal balloon delays and decreases gastro-oesophageal and bronchial aspiration of gastric content in patients carrying a nasogastric tube and receiving enteral nutrition during mechanical ventilation. Although the method was found to be safe when applied for 8 h, longer times should be considered with caution. PMID:12952272

  8. Mechanical ventilation and intra-abdominal hypertension: 'Beyond Good and Evil'.

    PubMed

    Pelosi, Paolo; Vargas, Maria

    2012-01-01

    Intra-abdominal hypertension is frequent in surgical and medical critically ill patients. Intra-abdominal hypertension has a serious impact on the function of respiratory as well as peripheral organs. In the presence of alveolar capillary damage, which occurs in acute respiratory distress syndrome (ARDS), intra-abdominal hypertension promotes lung injury as well as edema, impedes the pulmonary lymphatic drainage, and increases intra-thoracic pressures, leading to atelectasis, airway closure, and deterioration of respiratory mechanics and gas exchange. The optimal setting of mechanical ventilation and its impact on respiratory function and hemodynamics in ARDS associated with intra-abdominal hypertension are far from being assessed. We suggest that the optimal ventilator management of patients with ARDS and intra-abdominal hypertension would include the following: (a) intra-abdominal, esophageal pressure, and hemodynamic monitoring; (b) ventilation setting with protective tidal volume, recruitment maneuver, and level of positive end-expiratory pressure set according to the 'best' compliance of the respiratory system or the lung; (c) deep sedation with or without neuromuscular paralysis in severe ARDS; and (d) open abdomen in selected patients with severe abdominal compartment syndrome. PMID:23256904

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

    PubMed Central

    2013-01-01

    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 < .001). Initial fluconazole therapy remained associated with improved survival after adjusting for non-treatment factors in the overall population (hazard ratio .75, 95% CI .59–.96), and also among patients with albicans infection (hazard ratio .62, 95% CI .44–.88). While not statistically significant, fluconazole appeared to be associated with higher mortality among patients infected with glabrata (HR 1.13, 95% CI .70–1.84). Conclusions Among 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. PMID:24172136

  10. Pathophysiological Basis of Acute Respiratory Failure on Non-Invasive Mechanical Ventilation

    PubMed Central

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

    2015-01-01

    Noninvasive mechanical ventilation (NIMV) was created for patients who needed noninvasive ventilator support, this procedure decreases the complications associated with the use of endotracheal intubation (ETT). The application of NIMV has acquired major relevance in the last few years in the management of acute respiratory failure (ARF), in patients with hypoxemic and hypercapnic failure. The main advantage of NIMV as compared to invasive mechanical ventilation (IMV) is that it can be used earlier outside intensive care units (ICUs). The evidence strongly supports its use in patients with COPD exacerbation, support in weaning process in chronic obstructive pulmonary disease (COPD) patients, patients with acute cardiogenic pulmonary edema (ACPE), and Immunosuppressed patients. On the other hand, there is poor evidence that supports the use of NIMV in other pathologies such as pneumonia, acute respiratory distress syndrome (ARDS), and during procedures as bronchoscopy, where its use is still controversial because the results of these studies are inconclusive against the decrease in the rate of intubation or mortality. PMID:26312101

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

    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.

  12. Automated logging of inspiratory and expiratory non-synchronized breathing (ALIEN) for mechanical ventilation.

    PubMed

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

    2015-01-01

    Asynchronous Events (AEs) during mechanical ventilation (MV) result in increased work of breathing and potential poor patient outcomes. Thus, it is important to automate AE detection. In this study, an AE detection method, Automated Logging of Inspiratory and Expiratory Non-synchronized breathing (ALIEN) was developed and compared between standard manual detection in 11 MV patients. A total of 5701 breaths were analyzed (median [IQR]: 500 [469-573] per patient). The Asynchrony Index (AI) was 51% [28-78]%. The AE detection yielded sensitivity of 90.3% and specificity of 88.3%. Automated AE detection methods can potentially provide clinicians with real-time information on patient-ventilator interaction. PMID:26737491

  13. S2k-Guideline "Prolonged Weaning".

    PubMed

    Schönhofer, B; Geiseler, J; Dellweg, D; Moerer, O; Barchfeld, T; Fuchs, H; Karg, O; Rosseau, S; Sitter, H; Weber-Carstens, S; Westhoff, M; Windisch, W

    2015-10-01

    All mechanically ventilated patients must be weaned from the ventilator at some stage. According to an International Consensus Conference the criteria for "prolonged weaning" are fulfilled if patients fail at least 3 weaning attempts (i. e. spontaneous breathing trial, SBT) or require more than 7 days of weaning after the first SBT. This occurs in about 15 - 20 % of patients.Because of the growing number of patients requiring prolonged weaning a German guideline on prolonged weaning has been developed. It is an initiative of the German Respiratory Society (Deutsche Gesellschaft für Pneumologie und Beatmungsmedizin e. V., DGP) in cooperation with other societies (see acknowledgement) engaged in the field chaired by the Association of Scientific and Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF).This guideline deals with the definition, epidemiology, weaning categories, underlying pathophysiology, therapeutic strategies, the weaning unit, transition to out-of-hospital ventilation and therapeutic recommendations for end of life care. This short version summarises recommendations on prolonged weaning from the German guideline. PMID:26444135

  14. Influence of fluid and volume state on PaO2 oscillations in mechanically ventilated pigs.

    PubMed

    Bodenstein, Marc; Bierschock, Stephan; Boehme, Stefan; Wang, Hemei; Vogt, Andreas; Kwiecien, Robert; David, Matthias; Markstaller, Klaus

    2013-03-01

    Varying pulmonary shunt fractions during the respiratory cycle cause oxygen oscillations during mechanical ventilation. In artificially damaged lungs, cyclical recruitment of atelectasis is responsible for varying shunt according to published evidence. We introduce a complimentary hypothesis that cyclically varying shunt in healthy lungs is caused by cyclical redistribution of pulmonary perfusion. Administration of crystalloid or colloid infusions would decrease oxygen oscillations if our hypothesis was right. Therefore, n=14 mechanically ventilated healthy pigs were investigated in 2 groups: crystalloid (fluid) versus no-fluid administration. Additional volume interventions (colloid infusion, blood withdrawal) were carried out in each pig. Intra-aortal PaO2 oscillations were recorded using fluorescence quenching technique. Phase shift of oxygen oscillations during altered inspiratory to expiratory (I:E) ventilation ratio and electrical impedance tomography (EIT) served as control methods to exclude that recruitment of atelectasis is responsible for oxygen oscillations. In hypovolemia relevant oxygen oscillations could be recorded. Fluid and volume state changed PaO2 oscillations according to our hypothesis. Fluid administration led to a mean decline of 105.3 mmHg of the PaO2 oscillations amplitude (P<0.001). The difference of the amplitudes between colloid administration and blood withdrawal was 62.4 mmHg in pigs not having received fluids (P=0.0059). Fluid and volume state also changed the oscillation phase during altered I:E ratio. EIT excluded changes of regional ventilation (i.e., recruitment of atelectasis) to be responsible for these oscillations. In healthy pigs, cyclical redistribution of pulmonary perfusion can explain the size of respiratory-dependent PaO2 oscillations. PMID:23320977

  15. Noninvasive Mechanical Ventilation Improves Breathing-Swallowing Interaction of Ventilator Dependent Neuromuscular Patients: A Prospective Crossover Study

    PubMed Central

    Garguilo, Marine; Lejaille, Michèle; Vaugier, Isabelle; Orlikowski, David; Terzi, Nicolas; Lofaso, Frédéric; Prigent, Hélène

    2016-01-01

    Background Respiratory involvement in neuromuscular disorders may contribute to impaired breathing-swallowing interactions, swallowing disorders and malnutrition. We investigated whether the use of non-invasive ventilation (NIV) controlled by the patient could improve swallowing performances in a population of neuromuscular patients requiring daytime NIV. Methods Ten neuromuscular patients with severe respiratory failure requiring extensive NIV use were studied while swallowing without and with NIV (while ventilated with a modified ventilator allowing the patient to withhold ventilation as desired). Breathing-swallowing interactions were investigated by chin electromyography, cervical piezoelectric sensor, nasal flow recording and inductive plethysmography. Two water-bolus sizes (5 and 10ml) and a textured yogurt bolus were tested in a random order. Results NIV use significantly improved swallowing fragmentation (defined as the number of respiratory interruption of the swallowing of a single bolus) (p = 0.003) and breathing-swallowing synchronization (with a significant increase of swallows followed by an expiration) (p <0.0001). Patient exhibited piecemeal swallowing which was not influenced by NIV use (p = 0.07). NIV use also significantly reduced dyspnea during swallowing (p = 0.04) while preserving swallowing comfort, regardless of bolus type. Conclusion The use of patient controlled NIV improves swallowing parameters in patients with severe neuromuscular respiratory failure requiring daytime NIV, without impairing swallowing comfort. Trial Registration ClinicalTrials.gov NCT01519388 PMID:26938617

  16. The surgical repair of benign tracheo-oesophageal/pharyngeal fistula in patients on mechanical ventilation for severe neurological injuries†.

    PubMed

    Daddi, Niccolò; Tassi, Valentina; Belloni, Gian Piero; Mattioli, Sandro

    2016-04-01

    Acquired benign tracheo-oesophageal or pharyngeal fistulas (TO/PF) in neurological patients who cannot be weaned from mechanical ventilation represent a highly demanding clinical problem. We report on 3 patients on intermittent or continuous mechanical ventilation who successfully underwent tracheal resection and direct repair of the digestive fistula. Postoperative mechanical ventilation was provided through a modified silicone Safe-T-Tube, with which the cranial branch can be occluded with an internal inflatable balloon, inserted through tracheostomy performed at or below the level of the cricoid-tracheal suture line. Since the T prosthesis does not have an external cuff in the distal branch, a trans-tracheal open ventilation (TOV) technique was adopted. All patients, after a period that ranged from 21 h to 38 days from surgery, were restored to spontaneous breath; tracheal and oesophageal sutures healed normally. PMID:26306514

  17. Effect of feeding on ventilation and respiratory mechanics in newborn infants.

    PubMed Central

    Yu, V Y; Rolfe, P

    1976-01-01

    Measurements of ventilation and respiratory mechanics were made before and after tube feeding in 24 infants. In 12 infants with the respiratory distresssyndrome tidal volume tended to fall after feeding; as the respiratory rate increased after feeding; as the respiratory rate increased after feeding, minute ventilation remained unchanged. Hypoventilation is therefore unlikely to be the cause of hypoxaemia after feeding. Compliance, resistance, and the work of breathing showed no changes after feeding. In 12 healthy infants feeding had no effects on pulmonary function. There was a slight rise in compliance and a tendency for work of breathing to fall after feeding. Respiratory rate, tidal volume, and minute ventilation remained unchanged. There was therefore no evidence of adverse effects of feeding on any of the factors measured. It is suggested that hypoxaemia without hypoventilation after feeding in infants with pre-existing respiratory distress syndrome might be attributable to a reduction in functional residual capacity associated with a greater extent of airways closure than before feeding. PMID:818963

  18. Sulfide toxicity: Mechanical ventilation and hypotension determine survival rate and brain necrosis

    SciTech Connect

    Baldelli, R.J.; Green, F.H.Y.; Auer, R.N. )

    1993-09-01

    Occupational exposure to hydrogen sulfide is one of the leading causes of sudden death in the workplace, especially in the oil and gas industry. High-dose exposure causes immediate neurogenic apnea and death; lower doses cause [open quotes]knockdown[close quotes] (transient loss of consciousness, with apnea). Because permanent neurological sequelae have been reported, the authors sought to determine whether sulfide can directly kill central nervous system neurons. Ventilated and unventilated rats were studied to allow administration of higher doses of sulfide and to facilitate physiological monitoring. It was extremely difficult to produce cerebral necrosis with sulfide. Only one of eight surviving unventilated rats given high-dose sulfide (a dose that was lethal in [ge]50% of animals) showed cerebral necrosis. Mechanical ventilation shifted the dose that was lethal in 50% of the animals to 190 mg/kg from 94 mg/kg in the unventilated rats. Sulfide was found to potently depress blood pressure. Cerebral necrosis was absent in the ventilated rats (n = 11), except in one rat that showed profound and sustained hypotension to [le]35 Torr. Electroencephalogram activity ceased during exposure but recovered when the animals regained consciousness. The authors conclude that very-high-dose sulfide is incapable of producing cerebral necrosis by a direct histotoxic effect. 32 refs., 5 figs.

  19. Global survey on nebulization of antimicrobial agents in mechanically ventilated patients: a call for international guidelines.

    PubMed

    Solé-Lleonart, C; Roberts, J A; Chastre, J; Poulakou, G; Palmer, L B; Blot, S; Felton, T; Bassetti, M; Luyt, C-E; Pereira, J M; Riera, J; Welte, T; Qiu, H; Rouby, J-J; Rello, J

    2016-04-01

    Nebulized antimicrobial agents are increasingly administered for treatment of respiratory infections in mechanically ventilated (MV) patients. A structured online questionnaire assessing the indications, dosages and recent patterns of use for nebulized antimicrobial agents in MV patients was developed. The questionnaire was distributed worldwide and completed by 192 intensive care units. The most common indications for using nebulized antimicrobial agent were ventilator-associated tracheobronchitis (VAT; 58/87), ventilator-associated pneumonia (VAP; 56/87) and management of multidrug-resistant, Gram-negative (67/87) bacilli in the respiratory tract. The most common prescribed nebulized agents were colistin methanesulfonate and sulfate (36/87, 41.3% and 24/87, 27.5%), tobramycin (32/87, 36.7%) and amikacin (23/87, 26.4%). Colistin methanesulfonate, amikacin and tobramycin daily doses for VAP were significantly higher than for VAT (p < 0.05). Combination of parenteral and nebulized antibiotics occurred in 50 (86%) of 58 prescriptions for VAP and 36 (64.2%) of 56 of prescriptions for VAT. The use of nebulized antimicrobial agents in MV patients is common. There is marked heterogeneity in clinical practice, with significantly different in use between patients with VAP and VAT. Randomized controlled clinical trials and international guidance on indications, dosing and antibiotic combinations to improve clinical outcomes are urgently required. PMID:26723563

  20. A micromechanical model for estimating alveolar wall strain in mechanically ventilated edematous lungs.

    PubMed

    Chen, Zheng-long; Chen, Ya-zhu; Hu, Zhao-yan

    2014-09-15

    To elucidate the micromechanics of pulmonary edema has been a significant medical concern, which is beneficial to better guide ventilator settings in clinical practice. In this paper, we present an adjoining two-alveoli model to quantitatively estimate strain and stress of alveolar walls in mechanically ventilated edematous lungs. The model takes into account the geometry of the alveolus, the effect of surface tension, the length-tension properties of parenchyma tissue, and the change in thickness of the alveolar wall. On the one hand, our model supports experimental findings (Perlman CE, Lederer DJ, Bhattacharya J. Am J Respir Cell Mol Biol 44: 34-39, 2011) that the presence of a liquid-filled alveolus protrudes into the neighboring air-filled alveolus with the shared septal strain amounting to a maximum value of 1.374 (corresponding to the maximum stress of 5.12 kPa) even at functional residual capacity; on the other hand, it further shows that the pattern of alveolar expansion appears heterogeneous or homogeneous, strongly depending on differences in air-liquid interface tension on alveolar segments. The proposed model is a preliminary step toward picturing a global topographical distribution of stress and strain on the scale of the lung as a whole to prevent ventilator-induced lung injury. PMID:24947025

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

    SciTech Connect

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

    2011-11-08

    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.

  2. Effects of thoracic squeezing on airway secretion removal in mechanically ventilated patients

    PubMed Central

    Yousefnia-Darzi, Farkhondeh; Hasavari, Farideh; Khaleghdoost, Tahereh; Kazemnezhad-Leyli, Ehsan; Khalili, Malahat

    2016-01-01

    Background: Accumulation of secretions in the airways of patients with an endotracheal tube and mechanical ventilation will have serious consequences. One of the most common methods of airway clearance is endotracheal suctioning. In order to facilitate discharge of airway secretion resulting in promotion of gas exchange, chest physiotherapy techniques can be used at the time of expiration before suction. Materials and Methods: In this clinical trial with a cross-over design, 50 mechanically ventilated patients admitted to intensive care units (ICUs) were randomly divided into two groups of thoracic squeezing. In each patient, two interventions of endotracheal suctioning were conducted, one with and the other without thoracic squeezing during exhalation, with a 3 h gap between the two interventions and an elapse of three respiratory cycles between the number of compressions. Sputum secreted was collected in a container connected to a suction catheter and weighed. Data were recorded in data gathering forms and analyzed using descriptive and inferential statistics (Wilcoxon and independent t-test, Chi-square) in SPSS version 16. Results: Findings showed that the mean weight of the suction secretions removed from airway without thoracic squeezing was 1.35 g and that of suction secretions removed by thoracic squeezing was 1.94 g. Wilcoxon test showed a significant difference regarding the rate of secretion between the two techniques (P = 0.003). Conclusions: According to the study findings, endotracheal suction with thoracic squeezing on expiration helps airway secretion discharge more than suction alone in patients on mechanical ventilators and can be used as an effective method. PMID:27186214

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

    PubMed

    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

    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

  4. Indications for manual lung hyperinflation (MHI) in the mechanically ventilated patient with chronic obstructive pulmonary disease.

    PubMed

    Ntoumenopoulos, G

    2005-01-01

    Manual lung hyperinflation (MHI) can enhance secretion clearance, improve total lung/thorax compliance and assist in the resolution of acute atelectasis. To enhance secretion clearance in the intubated patient, the evidence highlights the need to maximize expiratory flow. Chronic pulmonary diseases such as chronic obstructive pulmonary disease (COPD) have often been cited as potential precautions and/or contra-indications to the use of manual lung hyperinflation (MHI). There is an absence of evidence on the effects of MHI in the patient with COPD. Research on the effects of mechanical ventilation in the patient with COPD provides a useful clinical examination of the effect of positive pressure on cardiac and pulmonary function. The potential effects of MHI in the COPD patient group were extrapolated on the basis of the MHI and mechanical ventilation literature. There is the potential for MHI to have both detrimental and beneficial effects on cardiac and pulmonary function in patients with COPD. The potential detrimental effects of MHI may include either, increased intrinsic peep through inadequate time for expiration by the breath delivery rate, tidal volume delivered or through the removal of applied external PEEP thereby causing more dynamic airway compression compromising downward expiratory flow, which may also retard bronchial mucus transport. MHI may also increase right ventricular after load through raised intrathoracic pressures with lung hyperinflation, and may therefore impair right ventricular function in patients with evidence of cor pulmonale. There is the potential for beneficial effects from MHI in the intubated COPD patient group (i.e., secretion clearance), but further research is required, especially on the effect of MHI on inspiratory and expiratory flow rate profiles in this patient group. The more controlled delivery of lung hyperinflation through the use of the mechanical ventilator may be a more optimal means of providing lung hyperinflation

  5. Effects of chemical feedback on respiratory motor and ventilatory output during different modes of assisted mechanical ventilation.

    PubMed

    Mitrouska, J; Xirouchaki, N; Patakas, D; Siafakas, N; Georgopoulos, D

    1999-04-01

    The purpose of the study was to examine the effects of chemical feedback on respiratory motor and ventilatory output in conscious subjects ventilated on various modes of assisted mechanical ventilation. Seven subjects were connected to a ventilator and randomly ventilated on assist-volume control (AVC), pressure support (PS) or proportional assist ventilation (PAV). On each mode, the assist level was set to the highest comfortable level. Airway and oesophageal (Poes) pressures, tidal volume, respiratory frequency (fR) and end-tidal carbon dioxide tension (PET,CO2) were measured breath-by-breath. When the subjects were stable on each mode, the fraction of inspired carbon dioxide (FI,CO2) was increased stepwise, and changes in minute ventilation (V'E) and respiratory motor output, estimated by the pressure-time product of all the respiratory muscles per breath (PTPrm) and per minute (PTPminute), were observed. At zero FI,CO2, PTPminute/PET,CO2 did not differ between modes, while V'E/ PTPminute was significantly lower with PAV than that with PS and AVC. As a result V'E/PET,CO2 was significantly lower with PAV, preventing, unlike AVC and PS, a significant drop in PET,CO2. With PAV, independent of CO2, V'E/PTPminute remained constant, while it decreased significantly with increasing CO2 stimulus with PS and AVC. At high PET,CO2 respiratory effort was significantly lower with PAV than that with PS and AVC. In conclusion, the mode of mechanical ventilation modifies the effects of chemical feedback on respiratory motor and ventilatory output. At all carbon dioxide stimulus levels neuroventilatory coupling was better preserved with proportional assist ventilation than with pressure support and assist-volume control ventilation. PMID:10362056

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

    PubMed Central

    2010-01-01

    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 May 2009. We found that in the immediate post-operative period following TAH placement, autocycling was present in 50% (5/10) of cases. There was immediate cessation of autocycling in all patients after being changed from a flow trigger of 2 L/minute to a pressure trigger of 2 cm H2O. The autocycling group was found to have significantly higher CVP values than the non-autocycling group (P = 0.012). Our data suggest that mechanical ventilator autocycling may be resolved or prevented by the use of a pressure trigger rather than a flow trigger setting in patients with TAHs who require mechanical ventilation. PMID:20478064

  7. Functional residual capacity tool: A practical method to assess lung volume changes during pulmonary complications in mechanically ventilated patients.

    PubMed

    Veena, S; Palepu, Sudeep; Umamaheswara Rao, G S; Ramesh, V J

    2010-07-01

    In this report, we describe a patient in whom we used a functional residual capacity (FRC) tool available on a critical care ventilator to identify the loss of lung volume associated with pulmonary complications and increase in FRC with the application of a recruitment maneuver. The case report underlines the utility of the FRC tool in rapid visualization of the lung volume changes and the effects of application of corrective strategies in patients receiving mechanical ventilation. PMID:21253350

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

    NASA Astrophysics Data System (ADS)

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

    2010-04-01

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

  9. Response of respiratory motor output to varying pressure in mechanically ventilated patients.

    PubMed

    Xirouhaki, N; Kondili, E; Mitrouska, I; Siafakas, N; Georgopoulos, D

    1999-09-01

    It has been shown in mechanically ventilated patients that pressure support (PS) unloads the respiratory muscles in a graded fashion depending on the PS level. The downregulation of respiratory muscles could be mediated through chemical or load-related reflex feedback. To test this hypothesis, 8 patients with acute lung injury mechanically ventilated on PS mode (baseline PS) were studied. In Protocol A, PS was randomly decreased or increased by at least 5 cmH2O for two breaths. During this time, which is shorter than circulation delay, only changes in load-related reflex feedback were operating. Sixty trials where PS increased (high PS) for two breaths and 62 trials where PS decreased (low PS), also for two breaths were analysed. Thereafter, the patients were assigned randomly to baseline, low or high PS and ventilated in each level for 30 min (Protocol B). The last 2 min of each period were analysed. Respiratory motor output was assessed by total pressure generated by the respiratory muscles (Pmus), computed from oesophageal pressure (Poes). In Protocol A, alteration in PS caused significant changes in tidal volume (VT) without any effect on Pmus waveform except for neural expiratory time (ntE). ntE increased significantly with increasing PS. In Protocol B, Pmus was significantly down-regulated with increasing PS. Carbon dioxide tension in arterial blood (Pa,CO2) measured at the end of each period increased with decreasing PS. There was not any further alteration in ntE beyond that observed in Protocol A. These results indicate that the effect of load-related reflex on respiratory motor output is limited to timing. The downregulation of pressure generated by the respiratory muscles with steady-state increase in pressure support is due to a slow feedback system, which is probably chemical in nature. PMID:10543268

  10. Mechanical ventilation in patients in the intensive care unit of a general university hospital in southern Brazil: an epidemiological study

    PubMed Central

    Fialkow, Léa; Farenzena, Maurício; Wawrzeniak, Iuri Christmann; Brauner, Janete Salles; Vieira, Sílvia Regina Rios; Vigo, Alvaro; Bozzetti, Mary Clarisse

    2016-01-01

    OBJECTIVES: To determine the characteristics, the frequency and the mortality rates of patients needing mechanical ventilation and to identify the risk factors associated with mortality in the intensive care unit (ICU) of a general university hospital in southern Brazil. METHOD: Prospective cohort study in patients admitted to the ICU who needed mechanical ventilation for at least 24 hours between March 2004 and April 2007. RESULTS: A total of 1,115 patients admitted to the ICU needed mechanical ventilation. The mortality rate was 51%. The mean age (± standard deviation) was 57±18 years, and the mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 22.6±8.3. The variables independently associated with mortality were (i) conditions present at the beginning of mechanical ventilation, age (hazard ratio: 1.01; p<0.001); the APACHE II score (hazard ratio: 1.01; p<0.005); acute lung injury/acute respiratory distress syndrome (hazard ratio: 1.38; p=0.009), sepsis (hazard ratio: 1.33; p=0.003), chronic obstructive pulmonary disease (hazard ratio: 0.58; p=0.042), and pneumonia (hazard ratio: 0.78; p=0.013) as causes of mechanical ventilation; and renal (hazard ratio: 1.29; p=0.011) and neurological (hazard ratio: 1.25; p=0.024) failure, and (ii) conditions occurring during the course of mechanical ventilation, acute lung injuri/acute respiratory distress syndrome (hazard ratio: 1.31; p<0.010); sepsis (hazard ratio: 1.53; p<0.001); and renal (hazard ratio: 1.75; p<0.001), cardiovascular (hazard ratio: 1.32; p≤0.009), and hepatic (hazard ratio: 1.67; p≤0.001) failure. CONCLUSIONS: This large cohort study provides a comprehensive profile of mechanical ventilation patients in South America. The mortality rate of patients who required mechanical ventilation was higher, which may have been related to the severity of illness of the patients admitted to our ICU. Risk factors for hospital mortality included conditions present at the start of mechanical

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

    PubMed Central

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

    2013-01-01

    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. PMID:23930166

  12. Atrial Fibrillation on Intensive Care Unit Admission Independently Increases the Risk of Weaning Failure in Nonheart Failure Mechanically Ventilated Patients in a Medical Intensive Care Unit: A Retrospective Case-Control Study.

    PubMed

    Tseng, Yen-Han; Ko, Hsin-Kuo; Tseng, Yen-Chiang; Lin, Yi-Hsuan; Kou, Yu Ru

    2016-05-01

    Atrial fibrillation (AF) is one of the most frequent arrhythmias in clinical practice. Previous studies have reported the influence of AF on patients with heart failure (HF). The effect of AF on the non-HF critically ill patients in a medical intensive care unit (ICU) remains largely unclear. The study aimed to investigate the impact of AF presenting on ICU admission on the weaning outcome of non-HF mechanically ventilated patients in a medical ICU.A retrospective observational case-control study was conducted over a 1-year period in a medical ICU at Taipei Veterans General Hospital, a tertiary medical center in north Taiwan. Non-HF mechanically ventilated patients who were successful in their spontaneous breathing trial and underwent ventilator discontinuation were enrolled. The primary outcome measure was the ventilator status after the first episode of ventilator discontinuation.A total of 285 non-HF patients enrolled were divided into AF (n = 62) and non-AF (n = 223) groups. Compared with the non-AF patients, the AF patients were significantly associated with old age (P = 0.002), a higher rate of acute respiratory distress syndrome causing respiratory failure (P = 0.015), a higher percentage of sepsis before liberation from mechanical ventilation (MV) (P = 0.004), and a higher serum level of blood urea nitrogen on the day of liberation from MV (P = 0.003). Multivariate logistic regression analysis demonstrated that AF independently increased the risk of weaning failure [adjusted odds ratio (AOR), 3.268; 95% confidence interval (CI), 1.254-8.517; P = 0.015]. Furthermore, the AF patients were found to be independently associated with a high rate of ventilator dependence (log rank test, P = 0.026), prolonged total ventilator use (AOR, 1.979; 95% CI, 1.032-3.794; P = 0.040), increased length of ICU stay (AOR, 2.256; 95% CI, 1.049-4.849; P = 0.037), increased length of hospital stay (AOR, 2.921; 95% CI, 1.363-6.260; P = 0

  13. Driving pressure during assisted mechanical ventilation: Is it controlled by patient brain?

    PubMed

    Georgopoulos, Dimitris; Xirouchaki, Nectaria; Tzanakis, Nikolaos; Younes, Magdy

    2016-07-01

    Tidal volume (VT) is the controlled variable during passive mechanical ventilation (CMV) in order to avoid ventilator-induced-lung-injury. However, recent data indicate that the driving pressure [ΔP; VT to respiratory system compliance (Crs) ratio] is the parameter that best stratifies the risk of death. In order to study which variable (VT or ΔP) is controlled by critically ill patients, 108 previously studied patients were assigned to receive PAV+ (a mode that estimates Crs and permits the patients to select their own breathing pattern) after CMV, were re-analyzed. When patients were switched from CMV to PAV+ they controlled ΔP without constraining VT to narrow limits. VT was increased when the resumption of spontaneous breathing was associated with an increase in Crs. When ΔP was high during CMV, the patients (n=12) decreased it in 58 out of 67 measurements. We conclude that critically ill patients control the driving pressure by sizing the tidal volume to individual respiratory system compliance using appropriate feedback mechanisms aimed at limiting the degree of lung stress. PMID:26994756

  14. Reasons of PEG failure to eliminate gastroesophageal reflux in mechanically ventilated patients

    PubMed Central

    Douzinas, Emmanuel E; Andrianakis, Ilias; Livaditi, Olga; Bakos, Dimitrios; Flevari, Katerina; Goutas, Nikos; Vlachodimitropoulos, Dimitrios; Tasoulis, Marios-Konstantinos; Betrosian, Alex P

    2009-01-01

    AIM: To investigate factors predicting failure of percutaneous endoscopic gastrostomy (PEG) to eliminate gastroesophageal reflux (GER). METHODS: Twenty-nine consecutive mechanically ventilated patients were investigated. Patients were evaluated for GER by pH-metry pre-PEG and on the 7th post-PEG day. Endoscopic and histologic evidence of reflux esophagitis was also carried out. A beneficial response to PEG was considered when pH-metry on the 7th post-PEG day showed that GER was below 4%. RESULTS: Seventeen patients responded (RESP group) and 12 did not respond (N-RESP) to PEG. The mean age, sex, weight and APACHE II score were similar in both groups. GER (%) values were similar in both groups at baseline, but were significantly reduced in the RESP group compared with the N-RESP group on the 7th post-PEG day [2.5 (0.6-3.8) vs 8.1 (7.4-9.2, P < 0.001)]. Reflux esophagitis and the gastroesophageal flap valve (GEFV) grading differed significantly between the two groups (P = 0.031 and P = 0.020, respectively). Histology revealed no significant differences between the two groups. CONCLUSION: Endoscopic grading of GEFV and the presence of severe reflux esophagitis are predisposing factors for failure of PEG to reduce GER in mechanically ventilated patients. PMID:19916176

  15. Weaning Patients From Mechanical Ventilation: A Knowledge-Based System Approach

    PubMed Central

    Tong, David A.

    1990-01-01

    The WEANing PROtocol (WEANPRO) knowledge-based system assists respiratory therapists and nurses in weaning post-operative cardiovascular patients from mechanical ventilation in the intensive care unit. The knowledge contained in WEANPRO is represented by rules and is implemented in M.1® by Teknowledge, Inc. WEANPRO will run on any IBM® compatible microcomputer. WEANPRO's performance in weaning patients in the intensive care unit was evaluated three ways: (1) a statistical comparison between the mean number of arterial blood gases required to wean patients to a T-piece with and without the use of WEANPRO, (2) a critique of the suggestions offered by the system by clinicians not involved in the system development, and (3) an inspection of the user's acceptance of WEANPRO in the intensive care unit. The results of the evaluations revealed that using WEANPRO significantly decreases the number of arterial blood gas analyses needed to wean patients from total dependance on mechanical ventilation to independent breathing using a T-piece. In doing so, WEANPRO's suggestions are accurate and its use is accepted by the clinicians. Currently, WEANPRO is being used in the intensive care unit at the East Unit of Baptist Memorial Hospital in Memphis, Tennessee.

  16. Fluid flow and particle transport in mechanically ventilated airways. Part II: particle transport.

    PubMed

    Alzahrany, Mohammed; Van Rhein, Timothy; Banerjee, Arindam; Salzman, Gary

    2016-07-01

    The flow mechanisms that play a role on aerosol deposition were identified and presented in a companion paper (Timothy et al. in Med Biol Eng Comput. doi: 10.1007/s11517-015-1407-3 , 2015). In the current paper, the effects of invasive conventional mechanical ventilation waveforms and endotracheal tube (ETT) on the aerosol transport were investigated. In addition to the enhanced deposition seen at the carinas of the airway bifurcations, enhanced deposition was also seen in the right main bronchus due to impaction and turbulent dispersion resulting from the fluid structures created by jet caused by the ETT. The orientation of the ETT toward right bronchus resulted in a substantial deposition inside right lung compared to left lung. The deposition inside right lung was ~12-fold higher than left lung for all considered cases, except for the case of using pressure-controlled sinusoidal waveform where a reduction of this ratio by ~50 % was found. The total deposition during pressure constant, volume ramp, and ascending ramp waveforms was similar and ~1.44 times higher than deposition fraction when using pressure sinusoidal waveform. Varying respiratory waveform demonstrated a significant role on the deposition enhancement factors and give evidence of drug aerosol concentrations in key deposition sites, which may be significant for drugs with negative side effects in high concentrations. These observations are thought to be important for ventilation treatment strategy. PMID:26541600

  17. Ventilator-driven xenon ventilation studies

    SciTech Connect

    Chilcoat, R.T.; Thomas, F.D.; Gerson, J.I.

    1984-07-01

    A modification of a common commercial Xe-133 ventilation device is described for mechanically assisted ventilation imaging. The patient's standard ventilator serves as the power source controlling the ventilatory rate and volume during the xenon study, but the gases in the two systems are not intermixed. This avoids contamination of the ventilator with radioactive xenon. Supplemental oxygen and positive end-expiratory pressure (PEEP) are provided if needed. The system can be converted quickly for conventional studies with spontaneous respiration.

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

    PubMed Central

    2013-01-01

    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. PMID:23680299

  19. Time course analysis of mechanical ventilation-induced diaphragm contractile muscle dysfunction in the rat

    PubMed Central

    Corpeno, R; Dworkin, B; Cacciani, N; Salah, H; Bergman, H-M; Ravara, B; Vitadello, M; Gorza, L; Gustafson, A-M; Hedström, Y; Petersson, J; Feng, H-Z; Jin, J-P; Iwamoto, H; Yagi, N; Artemenko, K; Bergquist, J; Larsson, L

    2014-01-01

    Controlled mechanical ventilation (CMV) plays a key role in triggering the impaired diaphragm muscle function and the concomitant delayed weaning from the respirator in critically ill intensive care unit (ICU) patients. To date, experimental and clinical studies have primarily focused on early effects on the diaphragm by CMV, or at specific time points. To improve our understanding of the mechanisms underlying the impaired diaphragm muscle function in response to mechanical ventilation, we have performed time-resolved analyses between 6 h and 14 days using an experimental rat ICU model allowing detailed studies of the diaphragm in response to long-term CMV. A rapid and early decline in maximum muscle fibre force and preceding muscle fibre atrophy was observed in the diaphragm in response to CMV, resulting in an 85% reduction in residual diaphragm fibre function after 9–14 days of CMV. A modest loss of contractile proteins was observed and linked to an early activation of the ubiquitin proteasome pathway, myosin:actin ratios were not affected and the transcriptional regulation of myosin isoforms did not show any dramatic changes during the observation period. Furthermore, small angle X-ray diffraction analyses demonstrate that myosin can bind to actin in an ATP-dependent manner even after 9–14 days of exposure to CMV. Thus, quantitative changes in muscle fibre size and contractile proteins are not the dominating factors underlying the dramatic decline in diaphragm muscle function in response to CMV, in contrast to earlier observations in limb muscles. The observed early loss of subsarcolemmal neuronal nitric oxide synthase activity, onset of oxidative stress, intracellular lipid accumulation and post-translational protein modifications strongly argue for significant qualitative changes in contractile proteins causing the severely impaired residual function in diaphragm fibres after long-term mechanical ventilation. For the first time, the present study

  20. Effect of ultra-fast mild hypothermia using total liquid ventilation on hemodynamics and respiratory mechanics.

    PubMed

    Sage, Michaël; Nadeau, Mathieu; Kohlhauer, Matthias; Praud, Jean-Paul; Tissier, Renaud; Robert, Raymond; Walti, Hervé; Micheau, Philippe

    2016-08-01

    Ultra-fast cooling for mild therapeutic hypothermia (MTH) has several potential applications, including prevention of post-cardiac arrest syndrome. Ultra-fast MTH by total liquid ventilation (TLV) entails the sudden filling of the lungs with a cold perfluorocarbon liquid and its subsequent use to perform TLV. The present physiological study was aimed at assessing whether pulmonary and systemic hemodynamics as well as lung mechanics are significantly altered during this procedure. Pulmonary and systemic arterial pressures, cardiac output as well as airway resistance and respiratory system compliance were measured during ultra-fast MTH by TLV followed by rewarming and normothermia in six healthy juvenile lambs. Results show that none of the studied variables were altered upon varying the perfluorocarbon temperature from 12 to 41 °C. It is concluded that ultra-fast MTH by TLV does not have any deleterious effect on hemodynamics or lung mechanics in healthy juvenile lambs. PMID:27242031

  1. Mechanical ventilation in patients with chronic obstructive pulmonary disease and bronchial asthma

    PubMed Central

    Ahmed, Syed Moied; Athar, Manazir

    2015-01-01

    Chronic obstructive pulmonary disease (COPD) and bronchial asthma often complicate the surgical patients, leading to post-operative morbidity and mortality. Many authors have tried to predict post-operative pulmonary complications but not specifically in COPD. The aim of this review is to provide recent evidence-based guidelines regarding predictors and ventilatory strategies for mechanical ventilation in COPD and bronchial asthma patients. Using Google search for indexing databases, a search for articles published was performed using various combinations of the following search terms: ‘Predictors’; ‘mechanical ventilation’; COPD’; ‘COPD’; ‘bronchial asthma’; ‘recent strategies’. Additional sources were also identified by exploring the primary reference list. PMID:26556918

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

    PubMed

    Maddox, Christina; Pontin, David

    2013-06-01

    UK survival rates for long-term mechanically ventilated children have increased and paid carers are trained to care for them at home, however there is limited literature on carers' training needs and experience of sharing care. Using a qualitative abductive design, we purposively sampled experienced carers to generate data via diaries, semi-structured interviews, and researcher reflexive notes. Research ethics approval was granted from NHS and University committees. Five analytical themes emerged - Parent as expert; Role definition tensions; Training and Continuing Learning Needs; Mixed Emotions; Support Mechanisms highlighting the challenges of working in family homes for carers and their associated learning needs. Further work on preparing carers to share feelings with parents, using burnout prevention techniques, and building confidence is suggested. Carers highlight the lack of clinical supervision during their night-working hours. One solution may be to provide access to registered nurse support when working out-of-office hours. PMID:23711491

  3. Review of Residential Ventilation Technologies

    SciTech Connect

    Armin Rudd

    2005-08-30

    This paper reviews current and potential ventilation technologies for residential buildings, including a variety of mechanical systems, natural ventilation, and passive ventilation. with particular emphasis on North American climates and construction.

  4. A novel preterm respiratory mechanics active simulator to test the performances of neonatal pulmonary ventilators

    NASA Astrophysics Data System (ADS)

    Cappa, Paolo; Sciuto, Salvatore Andrea; Silvestri, Sergio

    2002-06-01

    A patient active simulator is proposed which is capable of reproducing values of the parameters of pulmonary mechanics of healthy newborns and preterm pathological infants. The implemented prototype is able to: (a) let the operator choose the respiratory pattern, times of apnea, episodes of cough, sobs, etc., (b) continuously regulate and control the parameters characterizing the pulmonary system; and, finally, (c) reproduce the attempt of breathing of a preterm infant. Taking into account both the limitation due to the chosen application field and the preliminary autocalibration phase automatically carried out by the proposed device, accuracy and reliability on the order of 1% is estimated. The previously indicated value has to be considered satisfactory in light of the field of application and the small values of the simulated parameters. Finally, the achieved metrological characteristics allow the described neonatal simulator to be adopted as a reference device to test performances of neonatal ventilators and, more specifically, to measure the time elapsed between the occurrence of a potentially dangerous condition to the patient and the activation of the corresponding alarm of the tested ventilator.

  5. In vitro study and semiempirical model for aerosol delivery control during mechanical ventilation.

    PubMed

    Vecellio, Laurent; Guérin, Claude; Grimbert, Daniel; De Monte, Michele; Diot, Patrice

    2005-06-01

    The object of this study was to evaluate in vitro the influence of various ventilatory parameters on the delivery of synchronized nebulization of terbutaline during mechanical ventilation and to determine a semiempirical model to control the quantity of aerosol delivered into the patient's lung. An ATOMISOR NL9 M jet nebulizer (La Diffusion Technique Francaise, France) was filled with terbutaline (Bricanyl, Astra-Zeneca, Sweden) and connected to the inspiratory line of a Horus ventilator (Taema, France). Nebulization was synchronized with the inspiratory phase. We assessed at the end of the endotracheal tube the quantity of terbutaline (terbutaline mass output) and the volume median diameter (VMD) by diffraction-laser method. There was a negative correlation between terbutaline mass output and inspiratory air flow ( r =-0.95, p <0.0001) and between VMD and inspiratory air flow ( r =-0.96, p <0.0001). Moreover, positive end-expiratory pressure levels between 0 cm and 8 cm of water did not significantly change the terbutaline output mass ( p =0.22). Total nebulization time and terbutaline mass output calculated by the mathematical model showed good agreement with experimental data. In conclusion, our semiempirical model allows calculation of the duration of the nebulization required to deliver a given mass of terbutaline into patient lungs. PMID:15803302

  6. Cardiorespiratory Mechanical Simulator for In Vitro Testing of Impedance Minute Ventilation Sensors in Cardiac Pacemakers.

    PubMed

    Marcelli, Emanuela; Cercenelli, Laura

    2016-01-01

    We developed a cardiorespiratory mechanical simulator (CRMS), a system able to reproduce both the cardiac and respiratory movements, intended to be used for in vitro testing of impedance minute ventilation (iMV) sensors in cardiac pacemakers. The simulator consists of two actuators anchored to a human thorax model and a software interface to control the actuators and to acquire/process impedance signals. The actuators can be driven separately or simultaneously to reproduce the cardiac longitudinal shortening at a programmable heart rate and the diaphragm displacement at a programmable respiratory rate (RR). A standard bipolar pacing lead moving with the actuators and a pacemaker case fixed to the thorax model have been used to measure impedance (Z) variations during the simulated cardiorespiratory movements. The software is able to discriminate the low-frequency component because of respiration (Z(R)) from the high-frequency ripple because of cardiac effect (Z(C)). Impedance minute ventilation is continuously calculated from Z(R) and RR. From preliminary tests, the CRMS proved to be a reliable simulator for in vitro evaluation of iMV sensors. Respiration impedance recordings collected during cardiorespiratory movements reproduced by the CRMS were comparable in morphology and amplitude with in vivo assessments of transthoracic impedance variations. PMID:26501915

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

    PubMed Central

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

    2015-01-01

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

  8. High frequency oscillatory and conventional mechanical ventilation in experimental surfactant deficiency: a study using a new infant ventilator technique.

    PubMed

    Schulze, A; Schaller, P; Gehrhardt, B; Mädler, H J; Dinger, J; Gmyrek, D; Winkler, U; Nitzsche, H; Mehler, H J

    1989-01-01

    The performance of a new infant ventilator system had to be evaluated. Technically it is characterized by flow (V)- and pressure (P)-transducers mounted immediately near the endotracheal tube. A microcomputer works as a function generator and governs servo-controllers for V and P thus offering a multiplicity of different modes both of the conventional (CMV) and high frequency oscillatory (HFO) type. The additional dead space imposed by the system is identical with its internal compressible volume of 2 ml. Serial pulmonary lavages were performed in 17 adult rabbits while on CMV. PaO2 per unit of mean airway pressure (MAP) decreased thereby from 95.9 +/- 29.3 to 9.0 +/- 6.7 (kPa/kPa). The animals were then alternately ventilated by HFO (5, 10, or 20 Hz) and CMV, at matched MAP's. No significant difference in PaO2 between the two methods was revealed in intra-animal comparisons except a slight superiority of CMV at MAP's above 1.7 kPa (P less than 0.05). There was no clear linear relationship between PaO2 and MAP both at CMV and HFO. A strong increase in PaO2 often occurred beyond a MAP threshold. In 37 postlavage HFO runs at 5 Hz in 13 animals volume amplitudes of 3.19 +/- 0.5 ml/kg of bodyweight resulted in PaCO2 levels of 6.29 +/- 1.87 kPa. Except in one experiment (10 Hz) volume amplitudes below the natural dead space produced arterial hypercapnia. PMID:2508336

  9. [Inject-ventilation in bronchoscopy (author's transl)].

    PubMed

    Gebert, E; Deilmann, M; Pedersen, P

    1979-08-01

    Jet ventilation initially described by Sanders has been modified and improved for use with the Storz bronchoscope. Theoretical and technical performance are discussed and the mechanical and physiological properties are dealt with e.g. FiO2, driving and endotracheal pressure, expiratory CO2 concentrations, blood gas analysis, pulmonary artery pressure and electrocardiographic changes. Using this method prolonged diagnostic and surgical procedures, such as cauterisation of bronchial adenoma, removal of foreign bodies from the airways especially of small children and bronchial toilet in status asthmaticus, are rendered free from problems for the anaesthetist. We believe that the inject ventilator is a very useful addition to endotracheal surgery. PMID:495920

  10. Brachial artery peak velocity variation to predict fluid responsiveness in mechanically ventilated patients

    PubMed Central

    2009-01-01

    Introduction Although several parameters have been proposed to predict the hemodynamic response to fluid expansion in critically ill patients, most of them are invasive or require the use of special monitoring devices. The aim of this study is to determine whether noninvasive evaluation of respiratory variation of brachial artery peak velocity flow measured using Doppler ultrasound could predict fluid responsiveness in mechanically ventilated patients. Methods We conducted a prospective clinical research in a 17-bed multidisciplinary ICU and included 38 mechanically ventilated patients for whom fluid administration was planned due to the presence of acute circulatory failure. Volume expansion (VE) was performed with 500 mL of a synthetic colloid. Patients were classified as responders if stroke volume index (SVi) increased ≥ 15% after VE. The respiratory variation in Vpeakbrach (ΔVpeakbrach) was calculated as the difference between maximum and minimum values of Vpeakbrach over a single respiratory cycle, divided by the mean of the two values and expressed as a percentage. Radial arterial pressure variation (ΔPPrad) and stroke volume variation measured using the FloTrac/Vigileo system (ΔSVVigileo), were also calculated. Results VE increased SVi by ≥ 15% in 19 patients (responders). At baseline, ΔVpeakbrach, ΔPPrad and ΔSVVigileo were significantly higher in responder than nonresponder patients [14 vs 8%; 18 vs. 5%; 13 vs 8%; P < 0.0001, respectively). A ΔVpeakbrach value >10% predicted fluid responsiveness with a sensitivity of 74% and a specificity of 95%. A ΔPPrad value >10% and a ΔSVVigileo >11% predicted volume responsiveness with a sensitivity of 95% and 79%, and a specificity of 95% and 89%, respectively. Conclusions Respiratory variations in brachial artery peak velocity could be a feasible tool for the noninvasive assessment of fluid responsiveness in patients with mechanical ventilatory support and acute circulatory failure. Trial Registration

  11. Lung Function and Organ Dysfunctions in 178 Patients Requiring Mechanical Ventilation During The 2009 Influenza A (H1N1) Pandemic

    PubMed Central

    2011-01-01

    , pH, platelet count, lactate dehydrogenase assay (LDH) and Sequential Organ Failure Assessment (SOFA) differed significantly between survivors and non-survivors. Lack of recovery of platelet count and persistence of leukocytosis were characteristic of non-survivors. Mortality was high (46%); and length of MV was 10 (6 to 17) days. Conclusions These patients had severe, hypoxemic respiratory failure compatible with ARDS that persisted over time, frequently requiring rescue therapies to support oxygenation. NIV use is not warranted, given its high failure rate. Death and evolution to prolonged mechanical ventilation were common outcomes. Persistence of thrombocytopenia, acidosis and leukocytosis, and high LDH levels found in non-survivors during the course of the disease might be novel prognostic findings. PMID:21849039

  12. Acute respiratory failure induced by mechanical pulmonary ventilation at a peak inspiratory pressure of 40 cmH2O.

    PubMed

    Tsuno, K; Sakanashi, Y; Kishi, Y; Urata, K; Tanoue, T; Higashi, K; Yano, T; Terasaki, H; Morioka, T

    1988-09-01

    The effects of high pressure mechanical pulmonary ventilation at a peak inspiratory pressure of 40 cmH(2)O were studied on the lungs of healthy newborn pigs (14-21 days after birth). Forty percent oxygen in nitrogen was used for ventilation to prevent oxygen intoxication. The control group (6 pigs) was ventilated for 48 hours at a peak inspiratory pressure less than 18 cmH(2)O and a PEEP of 3-5 cmH(2)O with a normal tidal volume, and a respiratory rate of 20 times/min. The control group showed few deleterious changes in the lungs for 48 hours. Eleven newborn pigs were ventilated at a peak inspiratory pressure of 40 cmH(2)O with a PEEP of 3-5 cmH(2)O and a respiratory rate of 20 times/min. To avoid respiratory alkalosis, a dead space was placed in the respiratory circuit, and normocarbia was maintained by adjusting dead space volume. In all cases in the latter group, severe pulmonary impairments, such as abnormal chest roentgenograms, hypoxemia, decreased total static lung compliance, high incidence of pneumothorax, congestive atelectasis, and increased lung weight were found within 48 hours of ventilation. When the pulmonary impairments became manifest, 6 of the 11 newborn pigs were switched to the conventional medical and ventilatory therapies for 3-6 days. However, all of them became ventilator dependent, and severe lung pathology was found at autopsy. These pulmonary insults by high pressure mechanical pulmonary ventilation could be occurring not infrequently in the respiratory management of patients with respiratory failure. PMID:15236077

  13. Autocycling and increase in intrinsic positive end-expiratory pressure during mechanical ventilation.

    PubMed

    Harboe, S; Hjalmarsson, S; Søreide, E

    2001-11-01

    Modern ventilators are complicated electronic instruments with microprocessors and software, with the possibility of technical errors and problems such as autocycling. Despite autocycling being recognized as a problem in textbooks and reviews, there are few reports about autocycling in the literature. We report a case where a sudden increase in respiratory frequency due to autocycling resulted in a dangerous increase in intrinsic positive end-expiratory pressure (intrinsic PEEP, PEEPi). We think our case illustrates that autocycling does occur, but that the exact underlying mechanism may be hard to document and understand for clinicians. To remedy this situation, we suggest that manufacture-independent technical expertise should be established to evaluate incidents and suggest improvements. PMID:11736686

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

    PubMed

    Tracy, Mary Fran; Chlan, Linda

    2011-06-01

    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

  15. Sedation and Analgesia in Mechanically Ventilated Preterm Neonates: Continue Standard of Care or Experiment?

    PubMed Central

    McPherson, Christopher

    2012-01-01

    Attention to comfort and pain control are essential components of neonatal intensive care. Preterm neonates are uniquely susceptible to pain and agitation, and these exposures have a negative impact on brain development. In preterm neonates, chronic pain and agitation are common adverse effects of mechanical ventilation, and opiates or benzodiazepines are the pharmacologic agents most often used for treatment. Questions remain regarding the efficacy, safety, and neurodevelopmental impact of these therapies. Both preclinical and clinical data suggest troubling adverse drug reactions and the potential for adverse longterm neurodevelopmental impact. The negative impacts of standard pharmacologic agents suggest that alternative agents should be investigated. Dexmedetomidine is a promising alternative therapy that requires further interprofessional and multidisciplinary research in this population. PMID:23413121

  16. [Postural therapy during mechanical pulmonary ventilation with PEEP in patients with unilateral lung damage].

    PubMed

    Neverin, V K; Vlasenko, A V; Mitrokhin, A A; Galushka, S V; Ostapchenko, D V; Shishkina, E V

    2000-01-01

    Mechanical ventilation of the lungs (MVL) with positive end expiratory pressure (PEEP) is difficult in patients with unilateral lung damage because of uneven distribution of volumes and pressures in the involved and intact lungs. Harmful effects are easier manifested under such conditions. Selective MVL with selective PEEP is widely used abroad for optimizing MVL, but this method is rather expensive and is not devoid of shortcomings. Our study carried out in 32 patients with unilateral lung involvement showed that traditional MVL with general PEEP can effectively (in 75% cases) regulate gaseous exchange and decrease its untoward effects if MVL is performed with the patient lying on the healthy side and not supine. MVL in patients with unilateral lung injury lying on the healthy side can be a simpler and cheaper alternative to selective MVL with selective PEEP. PMID:10833838

  17. Simultaneous temperature and humidity measurements in a mechanical ventilator using an optical fibre sensor

    NASA Astrophysics Data System (ADS)

    Hernandez, F. U.; Correia, R.; Morgan, S. P.; Hayes-Gill, B.; Evans, D.; Sinha, R.; Norris, A.; Harvey, D.; Hardman, J. G.; Korposh, S.

    2016-05-01

    An optical fibre sensor for simultaneous temperature and humidity measurements consisting of one fibre Bragg grating (FBG) to measure temperature and a mesoporous film of bilayers of Poly(allylamine hydrochloride)(PAH) and silica (SiO2) nanoparticles deposited onto the tip of the same fibre to measure humidity is reported. The hygroscopic film was created using the layer-by-layer (LbL) method and the optical reflection spectra were measured up to a maximum of 23 bilayers. The temperature sensitivity of the FBG was 10 pm/°C while the sensitivity to humidity was (-1.4x10-12 W / %RH) using 23 bilayers. The developed sensor was tested in the mechanical ventilator and temperature and humidity of the delivered artificial air was simultaneously measured. Once calibrated, the optical fibre sensor has the potential to control the absolute humidity as an essential part of critical respiratory care.

  18. [Amyotrophic neuralgia associated with bilateral phrenic paralysis treated with non-invasive mechanical ventilation].

    PubMed

    García García, María Del Carmen; Hernández Borge, Jacinto; Antona Rodríguez, María José; Pires Gonçalves, Pedro; García García, Gema

    2015-09-01

    Amyotrophic neuralgia is an uncommon neuropathy characterized by severe unilateral shoulder pain. Isolated or concomitant involvement of other peripheral motor nerves depending on the brachial plexus such as phrenic or laryngeal nerves is unusual(1). Its etiology is unknown, yet several explanatory factors have been proposed. Phrenic nerve involvement, either unilateral or bilateral, is exceedingly rare. Diagnosis relies on anamnesis, functional and imaging investigations and electromyogram. We report the case of a 48-year-old woman with a past history of renal transplantation due to proliferative glomerulonephritis with subsequent transplant rejection, who was eventually diagnosed with amyotrophic neuralgia with bilateral phrenic involvement, and who required sustained non-invasive mechanical ventilation. PMID:26049960

  19. [Helicopter transportation of a sedated, mechanically ventilated patient with cervical cord injury].

    PubMed

    Kato, Hideya; Nishiwaki, Yuko; Hosoi, Kunihiko; Shiomi, Naoto; Hirata, Masashi

    2013-09-01

    We report helicopter transportation of a sedated, mechanically ventilated patient with cervical cord injury. A 20-year-old male sustained traumatic injury to the cervical spinal cord during extracurricular activities in a college. On arrival at the hospital, a halo vest was placed on the patient and tracheostomy was performed. On the 38th hospital day, he was transported a distance of 520km by helicopter to a specialized hospital in Fukuoka for medical repatriation. Cabin space was narrow. Since power supply and carrying capacity were limited, battery-driven and portable medical devices were used. In consideration for patient's psychological stress, he was sedated with propofol. RSS (Ramsay sedation scale) scores were recorded to evaluate whether the patient was adequately sedated during helicopter transportation. Prior to transport, we rehearsed the sedation using bispectral index monitoring (BIS) in the hospital to further ensure the patient's safety during the transport. PMID:24063142

  20. Perceptions of Patients and Families who Received a Music Intervention During Mechanical Ventilation

    PubMed Central

    Chlan, Linda; Staugaitis, Abbey

    2015-01-01

    The intensive care unit (ICU) is a technologically-driven environment where critically ill patients and their families have significant physical and emotional experiences. Mechanically ventilated (MV) patients can experience significant distress from anxiety and pain. Music listening is one integrative intervention that has been shown to reduce anxiety as well as other symptoms that contribute to distress in MV patients. This is a report of MV patient and family experiences from a larger research study whose aim was to evaluate levels of anxiety and sedative exposure with use of a patient-directed music intervention. Understanding perceptions of MV patients and families regarding the effectiveness of music listening will guide improvement of their care. PMID:26301046

  1. Prevalence of Advance Directives Among Older Adults Admitted to Intensive Care Units and Requiring Mechanical Ventilation.

    PubMed

    Gamertsfelder, Elise M; Seaman, Jennifer Burgher; Tate, Judith; Buddadhumaruk, Praewpannarai; Happ, Mary Beth

    2016-04-01

    Because older adults are at high risk for hospitalization and potential decisional incapacity, advance directives are important components of pre-hospital advanced care planning, as they document individual preferences for future medical care. The prevalence of pre-hospital advance directive completion in 450 critically ill older adults requiring mechanical ventilation from two Mid-Atlantic hospitals is described, and demographic and clinical predictors of pre-hospital advance directive completion are explored. The overall advance directive completion rate was 42.4%, with those in older age groups (75 to 84 years and 85 and older) having approximately two times the odds of completion. No significant differences in the likelihood of advance directive completion were noted by sex, race, or admitting diagnosis. The relatively low prevalence of advance directive completion among older adults with critical illness and high mortality rate (24%) suggest a need for greater awareness and education. [Journal of Gerontological Nursing, 42(4), 34-41.]. PMID:26651862

  2. [Aerophagia due to noninvasive mechanical ventilation: a first manifestation of silent gastric carcinoma].

    PubMed

    Mayoralas Alises, S; Gómez Mendieta, M A; Díaz Lobato, S

    2003-07-01

    Noninvasive mechanical ventilation (NIV) techniques have proven useful in treating patients with respiratory insufficiency of various etiologies. The problems most frequently associated with this ventilatory technique are the appearance of nasal and oropharyngeal dryness, pressure sores where the nasal mask touches the skin, ocular irritation due to air leakage and epistaxis. Aerophagia appears in up to half the patients with NIV and may lead to discontinuing treatment. Drugs that accelerate gastrointestinal transit, changes in the respirator settings or changing the ventilatory modality may help to ameliorate the problem. When the symptoms arising from abdominal distension due to NIV are intense and persistent, the coexistence of an underlying abdominal pathology must be ruled out. We report the cases of two patients with these characteristics in whom gastroscopy revealed gastric carcinoma. We think that patients with persistent symptoms of aerophagia that cannot be controlled by the usual measures should undergo endoscopic exploration to rule out silent gastric disease. PMID:12846962

  3. Absence of TNF-α enhances inflammatory response in the newborn lung undergoing mechanical ventilation.

    PubMed

    Ehrhardt, Harald; Pritzke, Tina; Oak, Prajakta; Kossert, Melina; Biebach, Luisa; Förster, Kai; Koschlig, Markus; Alvira, Cristina M; Hilgendorff, Anne

    2016-05-15

    Bronchopulmonary dysplasia (BPD), characterized by impaired alveolarization and vascularization in association with lung inflammation and apoptosis, often occurs after mechanical ventilation with oxygen-rich gas (MV-O2). As heightened expression of the proinflammatory cytokine TNF-α has been described in infants with BPD, we hypothesized that absence of TNF-α would reduce pulmonary inflammation, and attenuate structural changes in newborn mice undergoing MV-O2 Neonatal TNF-α null (TNF-α(-/-)) and wild type (TNF-α(+/+)) mice received MV-O2 for 8 h; controls spontaneously breathed 40% O2 Histologic, mRNA, and protein analysis in vivo were complemented by in vitro studies subjecting primary pulmonary myofibroblasts to mechanical stretch. Finally, TNF-α level in tracheal aspirates from preterm infants were determined by ELISA. Although MV-O2 induced larger and fewer alveoli in both, TNF-α(-/-) and TNF-α(+/+) mice, it caused enhanced lung apoptosis (TUNEL, caspase-3/-6/-8), infiltration of macrophages and neutrophils, and proinflammatory mediator expression (IL-1β, CXCL-1, MCP-1) in TNF-α(-/-) mice. These differences were associated with increased pulmonary transforming growth factor-β (TGF-β) signaling, decreased TGF-β inhibitor SMAD-7 expression, and reduced pulmonary NF-κB activity in ventilated TNF-α(-/-) mice. Preterm infants who went on to develop BPD showed significantly lower TNF-α levels at birth. Our results suggest a critical balance between TNF-α and TGF-β signaling in the developing lung, and underscore the critical importance of these key pathways in the pathogenesis of BPD. Future treatment strategies need to weigh the potential benefits of inhibiting pathologic cytokine expression against the potential of altering key developmental pathways. PMID:27016588

  4. Inspiratory muscle training to enhance recovery from mechanical ventilation: a randomised trial

    PubMed Central

    Bissett, Bernie M; Leditschke, I Anne; Neeman, Teresa; Boots, Robert; Paratz, Jennifer

    2016-01-01

    Background In patients who have been mechanically ventilated, inspiratory muscles remain weak and fatigable following ventilatory weaning, which may contribute to dyspnoea and limited functional recovery. Inspiratory muscle training may improve inspiratory muscle strength and endurance following weaning, potentially improving dyspnoea and quality of life in this patient group. Methods We conducted a randomised trial with assessor-blinding and intention-to-treat analysis. Following 48 hours of successful weaning, 70 participants (mechanically ventilated ≥7 days) were randomised to receive inspiratory muscle training once daily 5 days/week for 2 weeks in addition to usual care, or usual care (control). Primary endpoints were inspiratory muscle strength and fatigue resistance index (FRI) 2 weeks following enrolment. Secondary endpoints included dyspnoea, physical function and quality of life, post-intensive care length of stay and in-hospital mortality. Results 34 participants were randomly allocated to the training group and 36 to control. The training group demonstrated greater improvements in inspiratory strength (training: 17%, control: 6%, mean difference: 11%, p=0.02). There were no statistically significant differences in FRI (0.03 vs 0.02, p=0.81), physical function (0.25 vs 0.25, p=0.97) or dyspnoea (−0.5 vs 0.2, p=0.22). Improvement in quality of life was greater in the training group (14% vs 2%, mean difference 12%, p=0.03). In-hospital mortality was higher in the training group (4 vs 0, 12% vs 0%, p=0.051). Conclusions Inspiratory muscle training following successful weaning increases inspiratory muscle strength and quality of life, but we cannot confidently rule out an associated increased risk of in-hospital mortality. Trial registration number ACTRN12610001089022, results. PMID:27257003

  5. Early sedation and clinical outcomes of mechanically ventilated patients: a prospective multicenter cohort study

    PubMed Central

    2014-01-01

    Introduction Sedation overuse is frequent and possibly associated with poor outcomes in the intensive care unit (ICU) patients. However, the association of early oversedation with clinical outcomes has not been thoroughly evaluated. The aim of this study was to assess the association of early sedation strategies with outcomes of critically ill adult patients under mechanical ventilation (MV). Methods A secondary analysis of a multicenter prospective cohort conducted in 45 Brazilian ICUs, including adult patients requiring ventilatory support and sedation in the first 48 hours of ICU admissions, was performed. Sedation depth was evaluated after 48 hours of MV. Multivariate analysis was used to identify variables associated with hospital mortality. Results A total of 322 patients were evaluated. Overall, ICU and hospital mortality rates were 30.4% and 38.8%, respectively. Deep sedation was observed in 113 patients (35.1%). Longer duration of ventilatory support was observed (7 (4 to 10) versus 5 (3 to 9) days, P = 0.041) and more tracheostomies were performed in the deep sedation group (38.9% versus 22%, P = 0.001) despite similar PaO2/FiO2 ratios and acute respiratory distress syndrome (ARDS) severity. In a multivariate analysis, age (Odds Ratio (OR) 1.02; 95% confidence interval (CI) 1.00 to 1.03), Charlson Comorbidity Index >2 (OR 2.06; 95% CI, 1.44 to 2.94), Simplified Acute Physiology Score 3 (SAPS 3) score (OR 1.02; CI 95%, 1.00 to 1.04), severe ARDS (OR 1.44; CI 95%, 1.09 to 1.91) and deep sedation (OR 2.36; CI 95%, 1.31 to 4.25) were independently associated with increased hospital mortality. Conclusions Early deep sedation is associated with adverse outcomes and constitutes an independent predictor of hospital mortality in mechanically ventilated patients. PMID:25047960

  6. Mechanisms of nasal high flow on ventilation during wakefulness and sleep.

    PubMed

    Mündel, Toby; Feng, Sheng; Tatkov, Stanislav; Schneider, Hartmut

    2013-04-01

    Nasal high flow (NHF) has been shown to increase expiratory pressure and reduce respiratory rate but the mechanisms involved remain unclear. Ten healthy participants [age, 22 ± 2 yr; body mass index (BMI), 24 ± 2 kg/m(2)] were recruited to determine ventilatory responses to NHF of air at 37°C and fully saturated with water. We conducted a randomized, controlled, cross-over study consisting of four separate ∼60-min visits, each 1 wk apart, to determine the effect of NHF on ventilation during wakefulness (NHF at 0, 15, 30, and 45 liters/min) and sleep (NHF at 0, 15, and 30 liters/min). In addition, a nasal cavity model was used to compare pressure/air-flow relationships of NHF and continuous positive airway pressure (CPAP) throughout simulated breathing. During wakefulness, NHF led to an increase in tidal volume from 0.7 ± 0.1 liter to 0.8 ± 0.2, 1.0 ± 0.2, and 1.3 ± 0.2 liters, and a reduction in respiratory rate (fR) from 16 ± 2 to 13 ± 3, 10 ± 3, and 8 ± 3 breaths/min (baseline to 15, 30, and 45 liters/min NHF, respectively; P < 0.01). In contrast, during sleep, NHF led to a ∼20% fall in minute ventilation due to a decrease in tidal volume and no change in fR. In the nasal cavity model, NHF increased expiratory but decreased inspiratory resistance depending on both the cannula size and the expiratory flow rate. The mechanisms of action for NHF differ from those of CPAP and are sleep/wake-state dependent. NHF may be utilized to increase tidal breathing during wakefulness and to relieve respiratory loads during sleep. PMID:23412897

  7. Mechanical Ventilation and Clinical Outcomes in Patients with Acute Myocardial Infarction: A Retrospective Observational Study

    PubMed Central

    Pesaro, Antonio Eduardo P.; Katz, Marcelo; Katz, Jason N.; Barbas, Carmen Sílvia Valente; Makdisse, Marcia R.; Correa, Alessandra G.; Franken, Marcelo; Pereira, Carolina; Serrano, Carlos V.; Lopes, Renato D.

    2016-01-01

    Purpose Patients with acute myocardial infarction (AMI) and respiratory impairment may be treated with either invasive or non-invasive mechanical ventilation (MV). However, there has been little testing of non-invasive MV in the setting of AMI. Our objective was to evaluate the incidence and associated clinical outcomes of patients with AMI who were treated with non-invasive or invasive MV. Methods This was a retrospective observational study in which consecutive patients with AMI (n = 1610) were enrolled. The association between exclusively non-invasive MV, invasive MV and outcomes was assessed by multivariable models. Results Mechanical ventilation was used in 293 patients (54% invasive and 46% exclusively non-invasive). In-hospital mortality rates for patients without MV, with exclusively non-invasive MV, and with invasive MV were 4.0%, 8.8%, and 39.5%, respectively (P<0.001). The median lengths of hospital stay were 6 (5.8–6.2), 13 (11.2–4.7), and 28 (18.0–37.9) days, respectively (P<0.001). Exclusively non-invasive MV was not associated with in-hospital death (adjusted HR = 0.90, 95% CI 0.40–1.99, P = 0.79). Invasive MV was strongly associated with a higher risk of in-hospital death (adjusted HR = 3.07, 95% CI 1.79–5.26, P<0.001). Conclusions In AMI setting, 18% of the patients required MV. Almost half of these patients were treated with exclusively non-invasive strategies with a favorable prognosis, while patients who needed to be treated invasively had a three-fold increase in the risk of death. Future prospective randomized trials are needed to compare the effectiveness of invasive and non-invasive MV for the initial approach of respiratory failure in AMI patients. PMID:26977804

  8. Electroacupuncture improves gut barrier dysfunction in prolonged hemorrhagic shock rats through vagus anti-inflammatory mechanism

    PubMed Central

    Du, Ming-Hua; Luo, Hong-Min; Hu, Sen; Lv, Yi; Lin, Zhi-Long; Ma, Li

    2013-01-01

    AIM: To investigate whether electroacupuncture (EA) at Zusanli (ST36) prevents intestinal barrier and remote organ dysfunction following prolonged hemorrhagic shock through a vagus anti-inflammatory mechanism. METHODS: Sprague-Dawley rats were subjected to about 45% of total blood volume loss followed by delayed fluid replacement (DFR) with Ringer lactate 3h after hemorrhage. In a first study, rats were randomly divided into six groups: (1) EAN: EA at non-channel acupoints followed by DFR; (2) EA: EA at ST36 after hemorrhage followed by DFR; (3) VGX/EA: vagotomy (VGX) before EA at ST36 and DFR; (4) VGX/EAN: VGX before EAN and DFR; (5) α-bungarotoxin (α-BGT)/EA: intraperitoneal injection of α-BGT before hemorrhage, followed by EA at ST36 and DFR; and (6) α-BGT/EAN group: α-BGT injection before hemorrhage followed by EAN and DFR. Survival and mean arterial pressure (MAP) were monitored over the next 12 h. In a second study, with the same grouping and treatment, cytokine levels in plasma and intestine, organ parameters, gut injury score, gut permeability to 4 kDa FITC-dextran, and expression and distribution of tight junction protein ZO-1 were evaluated. RESULTS: MAP was significantly lowered after blood loss; EA at ST36 improved the blood pressure at corresponding time points 3 and 12 h after hemorrhage. EA at ST36 reduced tumor necrosis factor-α and interleukin (IL)-6 levels in both plasma and intestine homogenates after blood loss and DFR, while vagotomy or intraperitoneal injection of α-BGT before EA at ST36 reversed its anti-inflammatory effects, and EA at ST36 did not influence IL-10 levels in plasma and intestine. EA at ST36 alleviated the injury of intestinal villus, the gut injury score being significantly lower than that of EAN group (1.85 ± 0.33 vs 3.78 ± 0.59, P < 0.05). EA at ST36 decreased intestinal permeability to FITC-dextran compared with EAN group (856.95 ng/mL ± 90.65 ng/mL vs 2305.62 ng/mL ± 278.32 ng/mL, P < 0.05). EA at ST36

  9. The effects of the semirecumbent position on hemodynamic status in patients on invasive mechanical ventilation: prospective randomized multivariable analysis

    PubMed Central

    2013-01-01

    Introduction Adopting the 45° semirecumbent position in mechanically ventilated critically ill patients is recommended, as it has been shown to reduce the incidence of ventilator-associated pneumonia. Although the benefits to the respiratory system are clear, it is not known whether elevating the head of the bed results in hemodynamic instability. We examined the effect of head of bed elevation (HBE) on hemodynamic status and investigated the factors that influence mean arterial pressure (MAP) and central venous oxygen saturation (ScvO2) when patients were positioned at 0°, 30°, and 45°. Methods Two hundred hemodynamically stable adults on invasive mechanical ventilation admitted to a multidisciplinary surgical intensive care unit were recruited. Patients' characteristics included catecholamine and sedative doses, the original angle of head of bed elevation (HBE), the level of positive end expiratory pressure (PEEP), duration and mode of mechanical ventilation. A sequence of HBE positions (0°, 30°, and 45°) was adopted in random order, and MAP and ScvO2 were measured at each position. Patients acted as their own controls. The influence of degree of HBE and of the covariables on MAP and ScvO2 was analyzed by using liner mixed models. Additionally, uni- and multivariable logistic regression models were used to indentify risk factors for hypotension during HBE, defined as MAP <65 mmHg. Results Changing HBE from supine to 45° caused significant reductions in MAP (from 83.8 mmHg to 71.1 mmHg, P < 0.001) and ScvO2 (76.1% to 74.3%, P < 0.001). Multivariable modeling revealed that mode and duration of mechanical ventilation, the norepinephrine dose, and HBE had statistically significant influences. Pressure-controlled ventilation was the most influential risk factor for hypotension when HBE was 45° (odds ratio (OR) 2.33, 95% confidence interval (CI), 1.23 to 4.76, P = 0.017). Conclusions HBE to the 45° position is associated with significant decreases in MAP and

  10. Inhibition of Nitro-Oxidative Stress Attenuates Pulmonary and Systemic Injury Induced by High-Tidal Volume Mechanical Ventilation.

    PubMed

    Martínez-Caro, Leticia; Nin, Nicolás; Sánchez-Rodríguez, Carolina; Ferruelo, Antonio; El Assar, Mariam; de Paula, Marta; Fernández-Segoviano, Pilar; Esteban, Andrés; Lorente, José A

    2015-07-01

    Mechanisms contributing to pulmonary and systemic injury induced by high tidal volume (VT) mechanical ventilation are not well known. We tested the hypothesis that increased peroxynitrite formation is involved in organ injury and dysfunction induced by mechanical ventilation. Male Sprague-Dawley rats were subject to low- (VT, 9 mL/kg; positive end-expiratory pressure, 5 cmH2O) or high- (VT, 25 mL/kg; positive end-expiratory pressure, 0 cmH2O) VT mechanical ventilation for 120 min, and received 1 of 3 treatments: 3-aminobenzamide (3-AB, 10 mg/kg, intravenous, a poly adenosine diphosphate ribose polymerase [PARP] inhibitor), or the metalloporphyrin manganese(III) tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP, 5 mg/kg intravenous, a peroxynitrite scavenger), or no treatment (control group), 30 min before starting the mechanical ventilation protocol (n = 8 per group, 6 treatment groups). We measured mean arterial pressure, peak inspiratory airway pressure, blood chemistry, and gas exchange. Oxidation (fluorescence for oxidized dihydroethidium), protein nitration (immunofluorescence and Western blot for 3-nitrotyrosine), PARP protein (Western blot) and gene expression of the nitric oxide (NO) synthase (NOS) isoforms (quantitative real-time reverse transcription polymerase chain reaction) were measured in lung and vascular tissue. Lung injury was quantified by light microscopy. High-VT mechanical ventilation was associated with hypotension, increased peak inspiratory airway pressure, worsened oxygenation; oxidation and protein nitration in lung and aortic tissue; increased PARP protein in lung; up-regulation of NOS isoforms in lung tissue; signs of diffuse alveolar damage at histological examination. Treatment with 3AB or MnTMPyP attenuated the high-VT mechanical ventilation-induced changes in pulmonary and cardiovascular function; down-regulated the expression of NOS1, NOS2, and NOS3; decreased oxidation and nitration in lung and aortic tissue; and attenuated

  11. Ventilation and ventilators.

    PubMed

    Hayes, B

    1982-01-01

    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

  12. Intraoperative protective mechanical ventilation for prevention of postoperative pulmonary complications: a comprehensive review of the role of tidal volume, positive end-expiratory pressure, and lung recruitment maneuvers.

    PubMed

    Güldner, Andreas; Kiss, Thomas; Serpa Neto, Ary; Hemmes, Sabrine N T; Canet, Jaume; Spieth, Peter M; Rocco, Patricia R M; Schultz, Marcus J; Pelosi, Paolo; Gama de Abreu, Marcelo

    2015-09-01

    Postoperative pulmonary complications are associated with increased morbidity, length of hospital stay, and mortality after major surgery. Intraoperative lung-protective mechanical ventilation has the potential to reduce the incidence of postoperative pulmonary complications. This review discusses the relevant literature on definition and methods to predict the occurrence of postoperative pulmonary complication, the pathophysiology of ventilator-induced lung injury with emphasis on the noninjured lung, and protective ventilation strategies, including the respective roles of tidal volumes, positive end-expiratory pressure, and recruitment maneuvers. The authors propose an algorithm for protective intraoperative mechanical ventilation based on evidence from recent randomized controlled trials. PMID:26120769

  13. Flexible bronchoscopy during non-invasive positive pressure mechanical ventilation: are two better than one?

    PubMed

    Scala, Raffaele

    2016-09-01

    Flexible bronchoscopy (FBO) and non-invasive positive pressure ventilation (NIPPV) are largely applied in respiratory and general intensive care units. FBO plays a crucial role for the diagnosis of lung infiltrates of unknown origin and for the treatment of airways obstruction due to bronchial mucous plugging and hemoptysis in critical patients. NIPPV is the first-choice ventilatory strategy for acute respiratory failure (ARF) of different causes as it could be used as prevention or as alternative to the conventional mechanical ventilation (CMV) via endotracheal intubation (ETI). Some clinical scenarios represent contraindications for these techniques such as severe ARF in spontaneous breathing patients for FBO and accumulated tracheo-bronchial secretions in patients with depressed cough for NIPPV. In these contexts, the decision of performing ETI should carefully consider the risk of CMV-correlated complications. An increasing amount of published data suggested the use of FBO during NIPPV in ARF in order to avoid/reduce the need of ETI. Despite a strong rationale for the combined use of the two techniques, there is not still enough evidence for a large-scale application of this strategy in all different clinical scenarios. The majority of the available data are in favor of the "help" given by NIPPV to diagnostic FBO in high-risk spontaneously breathing patients with severe hypoxemia. Preliminary findings report the successful "help" given by early FBO to NIPPV in patients with hypoxemic-hypercapnic ARF who are likely to fail because of hypersecretion. Synergy of FBO and NIPPV application is emerging also to perform ETI in challenging situations, such as predicted difficult laringoscopy and NPPV failure in severely hypoxemic patients. This combined approach should be performed only in centers showing a wide experience with both NIPPV and FBO, where close monitoring and ETI facilities are promptly available. PMID:27012292

  14. Changes in pulse pressure variability during cardiac resynchronization therapy in mechanically ventilated patients

    PubMed Central

    Keyl, Cornelius; Stockinger, Jochem; Laule, Sven; Staier, Klaus; Schiebeling-Römer, Jochen; Wiesenack, Christoph

    2007-01-01

    Introduction The respiratory variation in pulse pressure (PP) has been established as a dynamic variable of cardiac preload which indicates fluid responsiveness in mechanically ventilated patients. The impact of acute changes in cardiac performance on respiratory fluctuations in PP has not been evaluated until now. We used cardiac resynchronization therapy as a model to assess the acute effects of changes in left ventricular performance on respiratory PP variability without the need of pharmacological intervention. Methods In 19 patients undergoing the implantation of a biventricular pacing/defibrillator device under general anesthesia, dynamic blood pressure regulation was assessed during right ventricular and biventricular pacing in the frequency domain (power spectral analysis) and in the time domain (PP variation: difference between the maximal and minimal PP values, normalized by the mean value). Results PP increased slightly during biventricular pacing but without statistical significance (right ventricular pacing, 33 ± 10 mm Hg; biventricular pacing, 35 ± 11 mm Hg). Respiratory PP fluctuations increased significantly (logarithmically transformed PP variability -1.27 ± 1.74 ln mm Hg2 versus -0.66 ± 1.48 ln mm Hg2; p < 0.01); the geometric mean of respiratory PP variability increased 1.8-fold during cardiac resynchronization. PP variation, assessed in the time domain and expressed as a percentage, showed comparable changes, increasing from 5.3% (3.1%; 12.3%) during right ventricular pacing to 6.9% (4.7%; 16.4%) during biventricular pacing (median [25th percentile; 75th percentile]; p < 0.01). Conclusion Changes in cardiac performance have a significant impact on respiratory hemodynamic fluctuations in ventilated patients. This influence should be taken into consideration when interpreting PP variation. PMID:17445270

  15. Mechanical Ventilation Alters the Development of Staphylococcus aureus Pneumonia in Rabbit

    PubMed Central

    Barbar, Saber-Davide; Pauchard, Laure-Anne; Bruyère, Rémi; Bruillard, Caroline; Hayez, Davy; Croisier, Delphine; Pugin, Jérôme; Charles, Pierre-Emmanuel

    2016-01-01

    Ventilator-associated pneumonia (VAP) is common during mechanical ventilation (MV). Beside obvious deleterious effects on muco-ciliary clearance, MV could adversely shift the host immune response towards a pro-inflammatory pattern through toll-like receptor (TLRs) up-regulation. We tested this hypothesis in a rabbit model of Staphylococcus aureus VAP. Pneumonia was caused by airway challenge with S. aureus, in either spontaneously breathing (SB) or MV rabbits (n = 13 and 17, respectively). Pneumonia assessment regarding pulmonary and systemic bacterial burden, as well as inflammatory response was done 8 and 24 hours after S. aureus challenge. In addition, ex vivo stimulations of whole blood taken from SB or MV rabbits (n = 7 and 5, respectively) with TLR2 agonist or heat-killed S. aureus were performed. Data were expressed as mean±standard deviation. After 8 hours of infection, lung injury was more severe in MV animals (1.40±0.33 versus [vs] 2.40±0.55, p = 0.007), along with greater bacterial concentrations (6.13±0.63 vs. 4.96±1.31 colony forming units/gram, p = 0.002). Interleukin (IL)-8 and tumor necrosis factor (TNF)-αserum concentrations reached higher levels in MV animals (p = 0.010). Whole blood obtained from MV animals released larger amounts of cytokines if stimulated with TLR2 agonist or heat-killed S. aureus (e.g., TNF-α: 1656±166 vs. 1005±89; p = 0.014). Moreover, MV induced TLR2 overexpression in both lung and spleen tissue. MV hastened tissue injury, impaired lung bacterial clearance, and promoted a systemic inflammatory response, maybe through TLR2 overexpression. PMID:27391952

  16. [The effectiveness of music therapy in reducing physiological and psychological anxiety in mechanically ventilated patients].

    PubMed

    Wu, Shiau-Jiun; Chou, Fan-Hao

    2008-10-01

    Anxiety, a common reaction in patients receiving ventilation therapy, often impacts negatively on patient recovery. Music therapy, a non-invasion intervention, is readily accepted by patients and has been used to relieve patient anxiety with encouraging results. The purpose of this study was to investigate the effectiveness of music therapy on reducing anxiety in patients on mechanical ventilators. An experimental design was used and all cases were collected from a medical center in southern Taiwan. While the experimental group patients took a 30-minute music therapy session, control group patients were asked to rest. Both facility anxiety and anxiety visual scales were used as research tools, with other non-invasive medical instruments employed to measure heartbeat and breathing, blood pressure and blood oxygen saturation in both patient groups. When compared with the control group, patients in the experimental group showed significant improvement in sense of anxiety (Brief Anxiety Scale, BAS, t(29) = -4.80, p < .001; Visual Analogue Anxiety Scales, VAAS, t(29) = -3.38, p = .002), diastolic pressure (t(29) = -2.74, p = .002), mean arterial pressure(t(29) = -2.26, p = .031) and breathing rate (t(29) = -4.84, p < .001). In analyzing data from the two groups, we found that the sense of anxiety (BAS, t(58) = -3.21, p = .002; VAAS, t(58) = -2.90, p = .005) and breathing rate (t(58) = -3.20, p = .002) in the experimental group decreased significantly following music therapy. Study results are hoped to serve as an important reference for clinical nursing staff. Also, it is hoped that the music therapy method may help facilitate achievement of broader humanized nursing goals. PMID:18836973

  17. Heterogeneity of cerebral vasoreactivity in preterm infants supported by mechanical ventilation

    SciTech Connect

    Pryds, O.; Greisen, G.; Lou, H.; Friis-Hansen, B. )

    1989-10-01

    The reaction of cerebral blood flow to acute changes in arterial carbon dioxide pressure (PaCO2) and mean arterial blood pressure was determined in 57 preterm infants supported by mechanical ventilation (mean gestational age 30.1 weeks) during the first 48 hours of life. All infants had normal brain sonograms at the time of the investigation. In each infant, global cerebral blood flow was determined by xenon-133 clearance two to five times within a few hours at different levels of PaCO2. Changes in PaCO2 followed adjustments of the ventilator settings. Arterial oxygen pressure was intended to be kept constant, and mean arterial blood pressure fluctuated spontaneously between measurements. The data were analyzed by stepwise multiple regression, with changes in global cerebral blood flow, PaCO2, mean arterial blood pressure, and postnatal age or intracranial hemorrhage used as variables. In infants with persistently normal brain sonograms, the global cerebral blood flow-carbon dioxide reactivity was markedly lower during the first day of life (mean 11.2% to 11.8%/kPa PaCO2) compared with the second day of life (mean 32.6/kPa PaCO2), and pressure-flow autoregulation was preserved. Similarly, global cerebral blood flow-carbon dioxide reactivity and pressure-flow autoregulation were present in infants in whom mild intracranial hemorrhage developed after the study. In contrast, global cerebral blood flow reactivity to changes in PaCO2 and mean arterial blood pressure was absent in infants in whom ultrasonographic signs of severe intracranial hemorrhage subsequently developed. These infants also had about 20% lower global cerebral blood flow before hemorrhage, in comparison with infants whose sonograms were normal, a finding that suggests functional disturbances of cerebral blood flow regulation.

  18. Evaluation of a Mapleson D CPAP system for weaning of mechanical ventilation in pediatric patients

    PubMed Central

    Palomero-Rodríguez, Miguel Angel; de Arteaga, Héctor Chozas; Báez, Yolanda Laporta; de Vicente Sánchez, Jesús; Carretero, Pascual Sanabria; Conde, Pilar Sánchez; Ferrer, Antonio Pérez

    2016-01-01

    Background: Over the last years, we have used a flow-inflating bag circuit with a nasotracheal or nasopharyngeal tube as an interface to deliver effective CPAP support in infants (“Mapleson D CPAP system”). The primary goal of this study was to assess the usefulness of the “Mapleson D CPAP system” for weaning of mechanical ventilation (MV) in infants who received MV over 24 h. Materials and Methods: All infants who received MV for more than 24 h in the last year were enrolled in the study. Demographic data included age, gender, weight, and admission diagnosis. Heart rate, respiratory rate, blood pressure, and oxygen saturation were measured during MV, 2 h after the nasotracheal Mapleson D CPAP system and 2 h after extubation. Patients were classified into two groups: patients MV more than 48 h, and patients with MV fewer than 48 h. P < 0.05 was considered statistically significant. Results: A total of 50 children were enrolled in the study, with a median age was 34 ± 45 months (range, 1–59 months) and median weight was 11.98 ± 9.31 kg (range, 1–48 kg). Median duration of MV was 480 h (range, 2–570). There were no significant differences in PaO2, PaCO2, and pH among MV, 2 h after the nasotracheal Mapleson D CPAP system and 2 h after extubation and spontaneous ventilation with the nasopharyngeal Mapleson D CPAP system or with nasal prongs. The overall extubation failure rate was 26% (n = 13). Weight and age were significantly associated with extubation failure (P < 0.05). Conclusions: The Mapleson D CPAP system, in our opinion, is a useful and safe alternative to more complex and expensive noninvasive CPAP and BiPAP weaning from MV in infants.

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

    PubMed Central

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

    2014-01-01

    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

  20. Mitogen-activated Protein Kinase Phosphatase-1 Modulates Regional Effects of Injurious Mechanical Ventilation in Rodent Lungs

    PubMed Central

    Park, Moo Suk; Edwards, Michael G.; Sergew, Amen; Riches, David W. H.; Albert, Richard K.

    2012-01-01

    Rationale: Mechanical ventilation induces heterogeneous lung injury by mitogen-activated protein kinase (MAPK) and nuclear factor-κB. Mechanisms regulating regional injury and protective effects of prone positioning are unclear. Objectives: To determine the key regulators of the lung regional protective effects of prone positioning in rodent lungs exposed to injurious ventilation. Methods: Adult rats were ventilated with high (18 ml/kg, positive end-expiratory pressure [PEEP] 0) or low Vt (6 ml/kg; PEEP 3 cm H2O; 3 h) in supine or prone position. Dorsal–caudal lung mRNA was analyzed by microarray and MAPK phosphatases (MKP)-1 quantitative polymerase chain reaction. MKP-1−/− or wild-type mice were ventilated with very high (24 ml/kg; PEEP 0) or low Vt (6–7 ml/kg; PEEP 3 cm H2O). The MKP-1 regulator PG490-88 (MRx-108; 0.75 mg/kg) or phosphate-buffered saline was administered preventilation. Injury was assessed by lung mechanics, bronchioalveolar lavage cell counts, protein content, and lung injury scoring. Immunoblotting for MKP-1, and IκBα and cytokine ELISAs were performed on lung lysates. Measurements and Main Results: Prone positioning was protective against injurious ventilation in rats. Expression profiling demonstrated MKP-1 20-fold higher in rats ventilated prone rather than supine and regional reduction in p38 and c-jun N-terminal kinase activation. MKP-1−/− mice experienced amplified injury. PG490-88 improved static lung compliance and injury scores, reduced bronchioalveolar lavage cell counts and cytokine levels, and induced MKP-1 and IκBα. Conclusions: Injurious ventilation induces MAPK in an MKP-1–dependent fashion. Prone positioning is protective and induces MKP-1. PG490-88 induced MKP-1 and was protective against high Vt in a nuclear factor-κB–dependent manner. MKP-1 is a potential target for modulating regional effects of injurious ventilation. PMID:22582160

  1. “Not Being Able to Talk was Horrid”: A Descriptive, Correlational Study of Communication During Mechanical Ventilation

    PubMed Central

    Guttormson, Jill L.; Bremer, Karin Lindstrom; Jones, Rachel M.

    2015-01-01

    Objectives The purpose of this study was to describe the patient experience of communication during mechanical ventilation Research Methodology This descriptive study is a secondary analysis of data collected to study the relationship between sedation and the MV patients' recall of the ICU. Interviews, conducted after extubation, included the Intensive Care Experience Questionnaire. Data were analyzed with Spearman correlation coefficients (rs) and content analysis. Setting Participants were recruited from a medical-surgical intensive care unit in the Midwest United States. Results Participants (n=31) with a mean age of 65 ± 11.9 were on the ventilator a median of 5 days. Inability to communicate needs was associated with helplessness (rs = .43). While perceived lack of information received was associated with not feeling in control (rs =.41) and helplessness (rs =.41). Ineffective communication negatively impacted satisfaction with care. Participants expressed frustration with failed communication and a lack of information received. They believed receipt of information helped them cope and desired a better system of communication during mechanical ventilation. Conclusion Communication effectiveness impacts patients' sense of safety and well-being during mechanical ventilation. Greater emphasis needs to be placed on the development and integration of communication strategies into critical care nursing practice. PMID:25579081

  2. [Sleep-apnea syndrome, mechanical ventilation and critical care in Archivos de Bronconeumología (December 2009-December 2010)].

    PubMed

    Abad Fernández, Araceli; Pumarega, Irene Cano; Hernández, Concepción; Sampol, Gabriel; Terán-Santos, Joaquín

    2011-01-01

    The present study aims to review all the major articles on respiratory sleep disorders, mechanical ventilation, and respiratory critical care published in the last year in Archivos de bronconeumología. Between December 2009 and November 2010, 15 studies on these topics were published in Archivos de bronconeumología. Ten of these studies dealt with respiratory sleep disorders, consisting of six original articles, one special article, one review article, one letter to the editor and one supplement on chronic obstructive pulmonary disease and its association with sleep apneas. Five articles were published on non-invasive mechanical ventilation: one editorial, one special article, one article in a supplement and two original articles. As in previous years, there was a marked difference in the number of articles published on non-invasive mechanical ventilation and sleep-apnea syndrome, with a greater number of articles being published on the latter. Although some articles highlight the importance of the place where ventilation is commenced, no study specifically dealing with intermediate care units was published in Archivos de bronconeumología in 2010. This absence could be interpreted as a result of the low implantation of this type of unit in Spain, contrasting with the high activity undertaken in this field by pneumology services. PMID:21300219

  3. Non-invasive mechanical ventilation and epidural anesthesia for an emergency open cholecystectomy.

    PubMed

    Yurtlu, Bülent Serhan; Köksal, Bengü; Hancı, Volkan; Turan, Işıl Özkoçak

    2016-01-01

    Non-invasive ventilation is an accepted treatment modality in both acute exacerbations of respiratory diseases and chronic obstructive lung disease. It is commonly utilized in the intensive care units, or for postoperative respiratory support in post-anesthesia care units. This report describes intraoperative support in non-invasive ventilation to neuroaxial anesthesia for an emergency upper abdominal surgery. PMID:27591472

  4. The effect of an upper respiratory care program on incidence of ventilator-associated pneumonia in mechanically ventilated patients hospitalized in intensive care units

    PubMed Central

    Bakhtiari, Soheila; Yazdannik, Ahmadreza; Abbasi, Saeid; Bahrami, Nasim

    2015-01-01

    Background: Ventilator-associated pneumonia (VAP) is a common side effect in patients with an endotracheal tube. This study aimed to evaluate the effect of an upper respiratory care program on the incidence of VAP in mechanically ventilated patients. Materials and Methods: In this clinical trial, 62 patients with endotracheal tube were selected and randomly allocated to intervention or control group. In the intervention group, an upper respiratory care program was performed and in the control group, routine care was done. Modified Clinical Pulmonary Infection Questionnaire was completed before, and on the third, fourth, and fifth day after intervention. Data were analyzed by repeated measure analysis of variance (ANOVA), chi-square, and independent t-test through SPSS 13. Results: The results of this study showed that until the fourth day, the incidence of VAP was similar in both intervention and control groups (P > 0.05), but on the fifth day, the incidence of VAP in the intervention group was significantly lower than in the control group (P < 0.05). Conclusions: The results of this study showed that in patients with an endotracheal tube, an upper respiratory care program may reduce the incidence of VAP. Therefore, in order to prevent VAP, nurses are recommended to perform this upper respiratory care program. PMID:26120336

  5. Comparison of Intravenous Palivizumab and Standard of Care for Treatment of Respiratory Syncytial Virus Infection in Mechanically Ventilated Pediatric Patients

    PubMed Central

    Ragsdale, Carolyn E.; Peterson, Evan J.; Merkel, Kathryn G.

    2016-01-01

    OBJECTIVES: Evidence suggests palivizumab may be beneficial for respiratory syncytial virus (RSV) infection in pediatric patients, although it is only approved by the US Food and Drug Administration for RSV prophylaxis. The objective of this study is to compare outcomes among pediatric patients with RSV infection who received intravenous palivizumab and standard of care versus standard of care alone. METHODS: This is a retrospective, single-center cohort study conducted between November 2003 and October 2013. Pediatric patients with active RSV infection treated with intravenous (IV) palivizumab after initiation of mechanical ventilation were matched 1:1 to a control selected from ventilated patients who received standard of care. The primary end point evaluated the duration of mechanical ventilation between groups. Secondary end points included hospital length of stay, intensive care unit length of stay, duration of respiratory support over baseline, time to RSV microbiologic cure, duration of antibiotic therapy, and in-hospital mortality. RESULTS: A total of 22 patients with a median age of 3 months were included in the study. Patients in the treatment group received a median of 2 doses of IV palivizumab, with a mean dose of 14.2 mg/kg. All patients received bronchodilators and corticosteroids, with the exception of 1 patient in the control group, and only 1 treatment group patient received IV ribavirin. Duration of mechanical ventilation was longer in the treatment group (18.9 ± 9.5 vs. 14.3 ± 9.3 days; p = 0.26). No statistically significant differences were observed between groups for any of the secondary end points. CONCLUSIONS: Pediatric patients who received IV palivizumab in addition to standard of care for treatment of RSV infection following initiation of mechanical ventilation experienced similar outcomes to those who received standard of care alone. Further studies are necessary to evaluate the potential benefit of IV palivizumab in addition to

  6. Lung stress, strain, and energy load: engineering concepts to understand the mechanism of ventilator-induced lung injury (VILI).

    PubMed

    Nieman, Gary F; Satalin, Joshua; Andrews, Penny; Habashi, Nader M; Gatto, Louis A

    2016-12-01

    It was recently shown that acute respiratory distress syndrome (ARDS) mortality has not been reduced in over 15 years and remains ~40 %, even with protective low tidal volume (LVt) ventilation. Thus, there is a critical need to develop novel ventilation strategies that will protect the lung and reduce ARDS mortality. Protti et al. have begun to analyze the impact of mechanical ventilation on lung tissue using engineering methods in normal pigs ventilated for 54 h. They used these methods to assess the impact of a mechanical breath on dynamic and static global lung strain and energy load. Strain is the change in lung volume in response to an applied stress (i.e., Tidal Volume-Vt). This study has yielded a number of exciting new concepts including the following: (1) Individual mechanical breath parameters (e.g., Vt or Plateau Pressure) are not directly correlated with VILI but rather any combination of parameters that subject the lung to excessive dynamic strain and energy/power load will cause VILI; (2) all strain is not equal; dynamic strain resulting in a dynamic energy load (i.e., kinetic energy) is more damaging to lung tissue than static strain and energy load (i.e., potential energy); and (3) a critical consideration is not just the size of the Vt but the size of the lung that is being ventilated by this Vt. This key concept merits attention since our current protective ventilation strategies are fixated on the priority of keeping the Vt low. If the lung is fully inflated, a large Vt is not necessarily injurious. In conclusion, using engineering concepts to analyze the impact of the mechanical breath on the lung is a novel new approach to investigate VILI mechanisms and to help design the optimally protective breath. Data generated using these methods have challenged some of the current dogma surrounding the mechanisms of VILI and of the components in the mechanical breath necessary for lung protection. PMID:27316442

  7. Management of Ventilatory Insufficiency in Neuromuscular Patients Using Mechanical Ventilator Supported by the Korean Government

    PubMed Central

    2016-01-01

    Since 2001, financial support has been provided for all patients with neuromuscular disease (NMD) who require ventilatory support due to the paralysis of respiratory muscles in Korea. The purpose of this study was to identify ventilator usage status and appropriateness in these patients. We included 992 subjects with rare and incurable NMD registered for ventilator rental fee support. From 21 February 2011 to 17 January 2013, ventilator usage information, regular follow-up observation, and symptoms of chronic hypoventilation were surveyed by phone. Home visits were conducted for patients judged by an expert medical team to require medical examination. Abnormal ventilatory status was assessed by respiratory evaluation. Chronic respiratory insufficiency symptoms were reported by 169 of 992 subjects (17%), while 565 subjects (57%) did not receive regular respiratory evaluation. Ventilatory status was abnormal in 102 of 343 home-visit subjects (29.7%). Although 556 subjects (56%) reported 24-hour ventilator use, only 458 (46%) had an oxygen saturation monitoring device, and 305 (31%) performed an airstacking exercise. A management system that integrates ventilator usage monitoring, counselling and advice, and home visits for patients who receive ventilator support could improve the efficiency of the ventilator support project. PMID:27247509

  8. A mathematical model approach quantifying patients' response to changes in mechanical ventilation: evaluation in volume support.

    PubMed

    Larraza, S; Dey, N; Karbing, D S; Jensen, J B; Nygaard, M; Winding, R; Rees, S E

    2015-04-01

    This paper presents a mathematical model-approach to describe and quantify patient-response to changes in ventilator support. The approach accounts for changes in metabolism (V̇O2, V̇CO2) and serial dead space (VD), and integrates six physiological models of: pulmonary gas-exchange; acid-base chemistry of blood, and cerebrospinal fluid; chemoreflex respiratory-drive; ventilation; and degree of patients' respiratory muscle-response. The approach was evaluated with data from 12 patients on volume support ventilation mode. The models were tuned to baseline measurements of respiratory gases, ventilation, arterial acid-base status, and metabolism. Clinical measurements and model simulated values were compared at five ventilator support levels. The models were shown to adequately describe data in all patients (χ(2), p > 0.2) accounting for changes in V̇CO2, VD and inadequate respiratory muscle-response. F-ratio tests showed that this approach provides a significantly better (p < 0.001) description of measured data than: (a) a similar model omitting the degree of respiratory muscle-response; and (b) a model of constant alveolar ventilation. The approach may help predict patients' response to changes in ventilator support at the bedside. PMID:25686673

  9. Management of Ventilatory Insufficiency in Neuromuscular Patients Using Mechanical Ventilator Supported by the Korean Government.

    PubMed

    Kang, Seong-Woong; Choi, Won Ah; Cho, Han Eol; Lee, Jang Woo; Park, Jung Hyun

    2016-06-01

    Since 2001, financial support has been provided for all patients with neuromuscular disease (NMD) who require ventilatory support due to the paralysis of respiratory muscles in Korea. The purpose of this study was to identify ventilator usage status and appropriateness in these patients. We included 992 subjects with rare and incurable NMD registered for ventilator rental fee support. From 21 February 2011 to 17 January 2013, ventilator usage information, regular follow-up observation, and symptoms of chronic hypoventilation were surveyed by phone. Home visits were conducted for patients judged by an expert medical team to require medical examination. Abnormal ventilatory status was assessed by respiratory evaluation. Chronic respiratory insufficiency symptoms were reported by 169 of 992 subjects (17%), while 565 subjects (57%) did not receive regular respiratory evaluation. Ventilatory status was abnormal in 102 of 343 home-visit subjects (29.7%). Although 556 subjects (56%) reported 24-hour ventilator use, only 458 (46%) had an oxygen saturation monitoring device, and 305 (31%) performed an airstacking exercise. A management system that integrates ventilator usage monitoring, counselling and advice, and home visits for patients who receive ventilator support could improve the efficiency of the ventilator support project. PMID:27247509

  10. On the relationship between air entrainment, internal flows and closure mechanism in a ventilated supercavity

    NASA Astrophysics Data System (ADS)

    Karn, Ashish; Arndt, Roger; Hong, Jiarong

    2015-11-01

    An understanding of underlying physics behind ventilation demand is critical for the operation of underwater vehicles based on ventilated supercavitation for a number of reasons viz. gas entrainment requirements for cavity formation and sustenance. The prior studies on the ventilation demand have reported that the gas entrainment requirement to form a supercavity is substantially larger than that needed to sustain it. This phenomenon, known as ventilation hysteresis, is particularly important from the viewpoint of reduction in gas requirements. However, little physical insights into this phenomenon has yet been provided. In this study, systematic investigations are conducted into ventilation hysteresis with respect to the formation and collapse behaviors of ventilated supercavities. It is suggested that the supercavity formation process is driven by bubble coalescence, whereas its collapse is related to the pressure difference across the supercavity interface at its rear portion. Further, we examine the relationship between ventilation hysteresis, supercavity closures and air entrainment requirements for supercavity formation and sustenance under steady and unsteady flow conditions. These observations are directly related to the internal flows inside the supercavity.

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

    PubMed Central

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

    2015-01-01

    Objective >To evaluate the agreement between a new epidemiological surveillance method of the Center for Disease Control and Prevention and the clinical pulmonary infection score for mechanical ventilator-associated pneumonia detection. Methods This was a prospective cohort study that evaluated patients in the intensive care units of two hospitals who were intubated for more than 48 hours between August 2013 and June 2014. Patients were evaluated daily by physical therapist using the clinical pulmonary infection score. A nurse independently applied the new surveillance method proposed by the Center for Disease Control and Prevention. The diagnostic agreement between the methods was evaluated. A clinical pulmonary infection score of ≥ 7 indicated a clinical diagnosis of mechanical ventilator-associated pneumonia, and the association of a clinical pulmonary infection score ≥ 7 with an isolated semiquantitative culture consisting of ≥ 104 colony-forming units indicated a definitive diagnosis. Results Of the 801 patients admitted to the intensive care units, 198 required mechanical ventilation. Of these, 168 were intubated for more than 48 hours. A total of 18 (10.7%) cases of mechanical ventilation-associated infectious conditions were identified, 14 (8.3%) of which exhibited possible or probable mechanical ventilatorassociated pneumonia, which represented 35% (14/38) of mechanical ventilator-associated pneumonia cases. The Center for Disease Control and Prevention method identified cases of mechanical ventilator-associated pneumonia with a sensitivity of 0.37, specificity of 1.0, positive predictive value of 1.0, and negative predictive value of 0.84. The differences resulted in discrepancies in the mechanical ventilator-associated pneumonia incidence density (CDC, 5.2/1000 days of mechanical ventilation; clinical pulmonary infection score ≥ 7, 13.1/1000 days of mechanical ventilation). Conclusion The Center for Disease Control and Prevention method failed to

  12. Ventilator-patient dyssynchrony induced by change in ventilation mode.

    PubMed

    Lydon, A M; Doyle, M; Donnelly, M B

    2001-06-01

    Patient-ventilator interactions may be coordinated (synchronous) or uncoordinated (dyssynchronous). Ventilator-patient dyssynchrony increases the work of breathing by imposing a respiratory muscle workload. Respiratory centre output responds to feedback from respiratory muscle loading. Mismatching of respiratory centre output and mechanical assistance results in dyssynchrony. We describe a case of severe patient-ventilator dyssynchrony and hypothesize that dyssynchrony was induced by a change in mode of ventilation from pressure-cycled to volume-cycled ventilation, due to both ventilator settings and by the patient's own respiratory centre adaptation to mechanical ventilation. The causes, management and clinical implications of dyssynchrony are discussed. PMID:11439799

  13. Endomicroscopic analysis of time- and pressure-dependent area of subpleural alveoli in mechanically ventilated rats.

    PubMed

    Runck, Hanna; Schwenninger, David; Haberstroh, Jörg; Guttmann, Josef

    2014-11-01

    We investigated the effects of recruitment maneuvers on subpleural alveolar area in healthy rats. 36 mechanically ventilated rats were allocated to either ZEEP-group or PEEP - 5cmH2O - group. The subpleural alveoli were observed using a transthoracal endoscopic imaging technique. Two consecutive low-flow maneuvers up to 30cmH2O peak pressure each were performed, interrupted by 5s plateau phases at four different pressure levels. Alveolar area change at maneuver peak pressures and during the plateau phases was calculated and respiratory system compliance before and after the maneuvers was analyzed. In both groups alveolar area at the second peak of the maneuver did not differ significantly compared to the first peak. During the plateau phases there was a slight increase in alveolar area. After the maneuvers, compliance increased by 30% in ZEEP group and 20% in PEEP group. We conclude that the volume insufflated by the low-flow recruitment maneuver is distributed to deeper but not to subpleural lung regions. PMID:25150503

  14. Building a Comprehensive System of Services to Support Adults Living with Long-Term Mechanical Ventilation

    PubMed Central

    Leasa, David; Elson, Stephen

    2016-01-01

    Background. Increasing numbers of individuals require long-term mechanical ventilation (LTMV) in the community. In the South West Local Health Integration Network (LHIN) in Ontario, multiple organizations have come together to design, build, and operate a system to serve adults living with LTMV. Objective. The goal was to develop an integrated approach to meet the health and supportive care needs of adults living with LTMV. Methods. The project was undertaken in three phases: System Design, Implementation Planning, and Implementation. Results. There are both qualitative and quantitative evidences that a multiorganizational system of care is now operational and functioning in a way that previously did not exist. An Oversight Committee and an Operations Management Committee currently support the system of services. A Memorandum of Understanding has been signed by the participating organizations. There is case-based evidence that hospital admissions are being avoided, transitions in care are being thoughtfully planned and executed collaboratively among service providers, and new roles and responsibilities are being accepted within the overall system of care. Conclusion. Addressing the complex and variable needs of adults living with LTMV requires a systems response involving the full continuum of care. PMID:27445527

  15. Pain assessment during blood collection from sedated and mechanically ventilated children

    PubMed Central

    Dantas, Layra Viviane Rodrigues Pinto; Dantas, Thiago Silveira Pinto; Santana-Filho, Valter Joviniano; Azevedo-Santos, Isabela Freire; DeSantana, Josimari Melo

    2016-01-01

    Objective This study assessed pain and observed physiological parameters in sedated and mechanically ventilated children during a routine procedure. Methods This observational study was performed in a pediatric intensive care unit. Thirty-five children between 1 month and 12 years of age were assessed before, during, and five minutes after an arterial blood collection for gas analysis (painful procedure). Face, Legs, Activity, Cry and Consolability scale was used to assess pain. In addition, patients' heart rate, respiratory rate, peripheral saturation of oxygen and blood pressure (diastolic and systolic) were recorded. COMFORT-B scale was applied before the pain and physiological parameter assessments to verify sedation level of the subjects. Results There was an increase in Face, Legs, Activity, Cry and Consolability score (p = 0.0001) during painful stimuli. There was an increase in heart rate (p = 0.03), respiratory rate (p = 0.001) and diastolic blood pressure (p = 0.006) due to pain caused by the routine procedure. Conclusions This study suggests that assessments of pain using standard scales, such as Face, Legs, Activity, Cry and Consolability score, and other physiological parameters should be consistently executed to optimize pain management in pediatric intensive care units. PMID:27096676

  16. Effects of age on the synergistic interactions between lipopolysaccharide and mechanical ventilation in mice.

    PubMed

    Smith, Lincoln S; Gharib, Sina A; Frevert, Charles W; Martin, Thomas R

    2010-10-01

    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-1β 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-β pathways. PMID:19901347

  17. Comparison of two methods to assess blood CO2 equilibration curve in mechanically ventilated patients.

    PubMed

    Cavaliere, Franco; Giovannini, Ivo; Chiarla, Carlo; Conti, Giorgio; Pennisi, Mariano A; Montini, Luca; Gaspari, Rita; Proietti, Rodolfo

    2005-03-01

    In order to compare two mathematical methods to assess the blood CO2 equilibration curve from a single blood gas analysis [Loeppky, J.A., Luft, U.C., Fletcher, E.R., 1983. Quantitative description of whole blood CO2 dissociation curve and Haldane effect. Resp. Physiol. 51, 167-181; Giovannini, I., Chiarla, C., Boldrini, G., Castagneto, M., 1993. Calculation of venoarterial CO2 concentration difference. J. Appl. Physiol. 74, 959-964], arterial and central venous blood gas analyses and oximetry were performed before and after ventilatory resetting, at constant arterial O2 saturation, in 12 mechanically ventilated patients. CO2 equilibration curves obtained from basal arterial blood gas analyses were used to predict arterial CO2 content after ventilatory resetting and vice versa. Internal consistency was very good for both methods and comparable. Method 2 also yielded excellent predictions of changes of arterial pH associated with ventilatory resetting. In determining Haldane effect, method 2 yielded very stable results within the expected range of values, while method 1 yielded a wider spread of results. Method 2 appeared more suitable to determine the Haldane effect in the conditions of the study, probably due to an approach minimizing the effect of potential sources of inaccuracy. PMID:15733781

  18. Building a Comprehensive System of Services to Support Adults Living with Long-Term Mechanical Ventilation.

    PubMed

    Leasa, David; Elson, Stephen

    2016-01-01

    Background. Increasing numbers of individuals require long-term mechanical ventilation (LTMV) in the community. In the South West Local Health Integration Network (LHIN) in Ontario, multiple organizations have come together to design, build, and operate a system to serve adults living with LTMV. Objective. The goal was to develop an integrated approach to meet the health and supportive care needs of adults living with LTMV. Methods. The project was undertaken in three phases: System Design, Implementation Planning, and Implementation. Results. There are both qualitative and quantitative evidences that a multiorganizational system of care is now operational and functioning in a way that previously did not exist. An Oversight Committee and an Operations Management Committee currently support the system of services. A Memorandum of Understanding has been signed by the participating organizations. There is case-based evidence that hospital admissions are being avoided, transitions in care are being thoughtfully planned and executed collaboratively among service providers, and new roles and responsibilities are being accepted within the overall system of care. Conclusion. Addressing the complex and variable needs of adults living with LTMV requires a systems response involving the full continuum of care. PMID:27445527

  19. Implementation Issues and Challenges for Computerized Clinical Protocols for Management of Mechanical Ventilation in ARDS Patients

    PubMed Central

    East, Thomas D.; Henderson, Susan; Morris, Alan H.; Gardner, Reed M.

    1989-01-01

    In the process of implementing complex computerized protocols for the management of ventilation in ARDS patients several unique problems were encountered in the areas of temporal dependency, testing, decision making architecture, data integrity, user interaction and order generation. The protocols are different from many of the applications previously developed in that they depend not only on the current status of the patient but the temporal sequence of events that led up to the present time. This necessitated timely charting which was not a small requirement in the demanding ICU environment. New testing tools had to be developed to simulate a temporal sequence of events so that all branches of the protocols could be thoroughly tested. The blackboard control architecture originally implemented had to be abandoned for the sake of data integrity. The inability to have interactive communication, during execution of the protocols required a thorough re-evaluation of the data which was routinely charted. The mechanism for triggering execution of the protocols had to be redesigned to provide shorter response time for the ICU environment. This new version of the protocols has been used in 16 patients for a total of 3553 therapy suggestions. It is now being generally accepted in the ICU and routinely used to treat a wide variety of respiratory failure patients.

  20. Early and simple detection of diastolic dysfunction during weaning from mechanical ventilation

    PubMed Central

    2012-01-01

    Weaning from mechanical ventilation imposes additional work on the cardiovascular system and can provoke or unmask left ventricular diastolic dysfunction with consecutive pulmonary edema or systolic dysfunction with inadequate increase of cardiac output and unsuccessful weaning. Echocardiography, which is increasingly used for hemodynamic assessment of critically ill patients, allows differentiation between systolic and diastolic failure. For various reasons, transthoracic echocardiographic assessment was limited to patients with good echo visibility and to those with sinus rhythm without excessive tachycardia. In these patients, often selected after unsuccessful weaning, echocardiographic findings were predictive for weaning failure of cardiac origin. In some studies, patients with various degrees of systolic dysfunction were included, making evaluation of the diastolic dysfunction to the weaning failure even more difficult. The recent study by Moschietto and coworkers included unselected patients and used very simple diastolic variables for assessment of diastolic function. They also included patients with atrial fibrillation and repeated echocardiographic examination only 10 minutes after starting a spontaneous breathing trial. The main finding was that weaning failure was not associated with systolic dysfunction but with diastolic dysfunction. By measuring simple and robust parameters for detection of diastolic dysfunction, the study was able to predict weaning failure in patients with sinus rhythm and atrial fibrillation as early as 10 minutes after beginning a spontaneous breathing trial. Further studies are necessary to determine whether appropriate treatment tailored according to the echocardiographic findings will result in successful weaning. PMID:22770365

  1. Effects of intravenous furosemide on mucociliary transport and rheological properties of patients under mechanical ventilation

    PubMed Central

    Kondo, Cláudia Seiko; Macchionne, Mariângela; Nakagawa, Naomi Kondo; de Carvalho, Carlos Roberto Ribeiro; King, Malcolm; Saldiva, Paulo Hilário Nascimento; Lorenzi-Filho, Geraldo

    2002-01-01

    The use of intravenous (IV) furosemide is common practice in patients under mechanical ventilation (MV), but its effects on respiratory mucus are largely unknown. Furosemide can affect respiratory mucus either directly through inhibition of the NaK(Cl)2 co-transporter on the basolateral surface of airway epithelium or indirectly through increased diuresis and dehydration. We investigated the physical properties and transportability of respiratory mucus obtained from 26 patients under MV distributed in two groups, furosemide (n = 12) and control (n = 14). Mucus collection was done at 0, 1, 2, 3 and 4 hours. The rheological properties of mucus were studied with a microrheometer, and in vitro mucociliary transport (MCT) (frog palate), contact angle (CA) and cough clearance (CC) (simulated cough machine) were measured. After the administration of furosemide, MCT decreased by 17 ± 19%, 24 ± 11%, 18 ± 16% and 18 ± 13% at 1, 2, 3 and 4 hours respectively, P < 0.001 compared with control. In contrast, no significant changes were observed in the control group. The remaining parameters did not change significantly in either group. Our results support the hypothesis that IV furosemide might acutely impair MCT in patients under MV. PMID:11940271

  2. A prognostic index for survival among mechanically ventilated hematopoietic cell transplant recipients.

    PubMed

    Solh, Melhem; Oommen, Sanjay; Vogel, Rachel Isaksson; Shanley, Ryan; Majhail, Navneet S; Burns, Linda J

    2012-09-01

    The prognosis of recipients of allogeneic hematopoietic cell transplantation (HCT) who require mechanical ventilation (MV) has historically been poor. Of 883 adults undergoing allogeneic HCT at the University of Minnesota between 1998 and 2009, 179 (20%) required MV before day 100 posttransplantation. We evaluated the outcomes of these patients to develop a prognostic index to predict the 100-day post-MV overall survival (OS) based on factors present at the time of MV. The 179 patients were divided at random into a training set (n = 119) and a validation set (n = 60). The 100-day postventilation OS was 17% for the total population. Multivariate Cox regression on the training set identified creatinine <2 mg/dL and platelet count >20 × 10(9)/L as significant predictors of better OS. Recursive partitioning classified patients with these good prognostic criteria into class A (n = 76); all other patients were classified as class B (n = 103). Among class A patients, 100-day OS was 29% in the training set and 30% in the validation set. Corresponding OS in class B patients was 5% and 15%, respectively. This prognostic index should help guide physicians in counseling HCT patients and their families regarding the use of MV and potential outcomes. PMID:22387348

  3. Quantitative imaging of alveolar recruitment with hyperpolarized gas MRI during mechanical ventilation.

    PubMed

    Cereda, Maurizio; Emami, Kiarash; Kadlecek, Stephen; Xin, Yi; Mongkolwisetwara, Puttisarn; Profka, Harrilla; Barulic, Amy; Pickup, Stephen; Månsson, Sven; Wollmer, Per; Ishii, Masaru; Deutschman, Clifford S; Rizi, Rahim R

    2011-02-01

    The aim of this study was to assess the utility of (3)He MRI to noninvasively probe the effects of positive end-expiratory pressure (PEEP) maneuvers on alveolar recruitment and atelectasis buildup in mechanically ventilated animals. Sprague-Dawley rats (n = 13) were anesthetized, intubated, and ventilated in the supine position ((4)He-to-O(2) ratio: 4:1; tidal volume: 10 ml/kg, 60 breaths/min, and inspiration-to-expiration ratio: 1:2). Recruitment maneuvers consisted of either a stepwise increase of PEEP to 9 cmH(2)O and back to zero end-expiratory pressure or alternating between these two PEEP levels. Diffusion MRI was performed to image (3)He apparent diffusion coefficient (ADC) maps in the middle coronal slices of lungs (n = 10). ADC was measured immediately before and after two recruitment maneuvers, which were separated from each other with a wait period (8-44 min). We detected a statistically significant decrease in mean ADC after each recruitment maneuver. The relative ADC change was -21.2 ± 4.1 % after the first maneuver and -9.7 ± 5.8 % after the second maneuver. A significant relative increase in mean ADC was observed over the wait period between the two recruitment maneuvers. The extent of this ADC buildup was time dependent, as it was significantly related to the duration of the wait period. The two postrecruitment ADC measurements were similar, suggesting that the lungs returned to the same state after the recruitment maneuvers were applied. No significant intrasubject differences in ADC were observed between the corresponding PEEP levels in two rats that underwent three repeat maneuvers. Airway pressure tracings were recorded in separate rats undergoing one PEEP maneuver (n = 3) and showed a significant relative difference in peak inspiratory pressure between pre- and poststates. These observations support the hypothesis of redistribution of alveolar gas due to recruitment of collapsed alveoli in presence of atelectasis, which was also supported by

  4. Role of the Fas/FasL system in a model of RSV infection in mechanically ventilated mice

    PubMed Central

    van den Berg, Elske; van Woensel, Job B. M.; Bos, Albert P.; Bem, Reinout A.; Altemeier, William A.; Gill, Sean E.; Martin, Thomas R.

    2011-01-01

    Infection with respiratory syncytial virus (RSV) in children can progress to respiratory distress and acute lung injury necessitating mechanical ventilation (MV). MV enhances apoptosis and inflammation in mice infected with pneumonia virus of mice (PVM), a mouse pneumovirus that has been used as a model for severe RSV infection in mice. We hypothesized that the Fas/Fas ligand (FasL) system, a dual proapoptotic/proinflammatory system involved in other forms of lung injury, is required for enhanced lung injury in mechanically ventilated mice infected with PVM. C57BL/6 mice and Fas-deficient (“lpr”) mice were inoculated intratracheally with PVM. Seven or eight days after PVM inoculation, the mice were subjected to 4 h of MV (tidal volume 10 ml/kg, fraction of inspired O2 = 0.21, and positive end-expiratory pressure = 3 cm H2O). Seven days after PVM inoculation, exposure to MV resulted in less severe injury in lpr mice than in C57BL/6 mice, as evidenced by decreased numbers of polymorphonuclear neutrophils in the bronchoalveolar lavage (BAL), and lower concentrations of the proinflammatory chemokines KC, macrophage inflammatory protein (MIP)-1α, and MIP-2 in the lungs. However, when PVM infection was allowed to progress one additional day, all of the lpr mice (7/7) died unexpectedly between 0.5 and 3.5 h after the onset of ventilation compared with three of the seven ventilated C57BL/6 mice. Parameters of lung injury were similar in nonventilated mice, as was the viral content in the lungs and other organs. Thus, the Fas/FasL system was partly required for the lung inflammatory response in ventilated mice infected with PVM, but attenuation of lung inflammation did not prevent subsequent mortality. PMID:21743025

  5. Air Distribution Effectiveness for Residential Mechanical Ventilation: Simulation and Comparison of Normalized Exposures

    SciTech Connect

    Petithuguenin, T.D.P.; Sherman, M.H.

    2009-05-01

    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).

  6. A new design for high stability pressure-controlled ventilation for small animal lung imaging

    NASA Astrophysics Data System (ADS)

    Kitchen, M. J.; Habib, A.; Fouras, A.; Dubsky, S.; Lewis, R. A.; Wallace, M. J.; Hooper, S. B.

    2010-02-01

    We have developed a custom-designed ventilator to deliver a stable pressure to the lungs of small animals for use in imaging experiments. Our ventilator was designed with independent pressure vessels to separately control the Peak Inspiratory Pressure (PIP) and Positive End Expiratory Pressure (PEEP) to minimise pressure fluctuations during the ventilation process. The ventilator was computer controlled through a LabVIEW interface, enabling experimental manipulations to be performed remotely whilst simultaneously imaging the lungs in situ. Mechanical ventilation was successfully performed on newborn rabbit pups to assess the most effective ventilation strategies for aerating the lungs at birth. Highly stable pressures enabled reliable respiratory gated acquisition of projection radiographs and a stable prolonged (15 minute) breath-hold for high-resolution computed tomography of deceased rabbit pups at different lung volumes.

  7. Intraoperative Autotriggered Pressure Support Ventilation Resistant to Increased Flow Trigger Threshold.

    PubMed

    Benitez Lopez, Julio; Rao, Sripad P; McNeer, Richard R; Dudaryk, Roman

    2016-07-01

    Oscillations from cardiac pulsations are normally transmitted to mediastinal structures without any consequence. Autotriggering (AT) of mechanical ventilation occurs when an inspiratory trigger, typically negative inspiratory flow in anesthesia ventilators, is met in the absence of patient effort. AT can lead to respiratory alkalosis, opioid overdose, prolonged mechanical ventilation, and lung hyperinflation. This entity has been reported in both critical care and operating room environments. Increasing the flow trigger usually resolves AT in all cases. We report a case of AT that failed to respond to increasing the flow trigger threshold to its maximal value on the GE Datex-Ohmeda Avance S5® anesthesia station. PMID:27224041

  8. Risk Factors for Mechanical Ventilation in Patients with Scrub Typhus Admitted to Intensive Care Unit at a University Hospital

    PubMed Central

    Moon, Kyoung Min; Rim, Ch'ang Bum; Lee, Jun Ho; Kang, Min Seok; Kim, Ji Hye; Kim, Sang Il; Jung, Sun Young; Cho, Yongseon

    2016-01-01

    Background The purpose of this study was to evaluate the risk factors for mechanical ventilation in the patients with scrub typhus admitted to intensive care unit (ICU) at a university hospital. Methods We retrospectively selected and analyzed clinical data from the medical records of 70 patients (32 men, 38 women) admitted to the ICU with scrub typhus between 2004 and 2014. The patients had a mean±standard deviation age of 71.2±11.1 years and were evaluated in two groups: those who had been treated with mechanical ventilation (the MV group, n=19) and those who had not (the non-MV group, n=51). Mean ages of the MV group and the non-MV group were 71.2±8.3 years and 71.2±11.1 years, respectively. Results Significant differences between the two groups were observed with respect to acute respiratory failure (p=0.008), Acute Physiology and Chronic Health Evaluation (APACHE) II score (p=0.015), Sequential Organ Failure Assessment (SOFA) score (p=0.013), death (p=0.014), and ICU duration (p<0.01). Multivariate analysis indicated that the following factors were significantly associated with mechanical ventilation: acute respiratory failure (p=0.011), SOFA score (p=0.005), APACHE II score (p=0.011), platelet count (p=0.009), and lactate dehydrogenase (LDH) (p=0.011). Conclusion Thus, five factors-acute respiratory failure, SOFA score, APACHE II score, platelet count, and LDH-can be the meaningful indicators for mechanical ventilation for the patients with scrub typhus admitted to ICU. PMID:26770232

  9. A simplified model for estimating population-scale energy impacts of building envelope air-tightening and mechanical ventilation retrofits

    SciTech Connect

    Logue, J. M.; Turner, W. J.N.; Walker, I. S.; Singer, B. C.

    2015-07-01

    Changing the air exchange rate of a home (the sum of the infiltration and mechanical ventilation airflow rates) affects the annual thermal conditioning energy. Large-scale changes to air exchange rates of the housing stock can significantly alter the residential sector’s energy consumption. However, the complexity of existing residential energy models is a barrier to the accurate quantification of the impact of policy changes on a state or national level.

  10. Effect of methacholine on peripheral lung mechanics and ventilation heterogeneity in asthma.

    PubMed

    Downie, Sue R; Salome, Cheryl M; Verbanck, Sylvia; Thompson, Bruce R; Berend, Norbert; King, Gregory G

    2013-03-15

    The forced oscillation technique (FOT) and multiple-breath nitrogen washout (MBNW) are noninvasive tests that are potentially sensitive to peripheral airways, with MBNW indexes being especially sensitive to heterogeneous changes in ventilation. The objective was to study methacholine-induced changes in the lung periphery of asthmatic patients and determine how changes in FOT variables of respiratory system reactance (Xrs) and resistance (Rrs) and frequency dependence of resistance (Rrs5-Rrs19) can be linked to changes in ventilation heterogeneity. The contributions of air trapping and airway closure, as extreme forms of heterogeneity, were also investigated. Xrs5, Rrs5, Rrs19, Rrs5-Rrs19, and inspiratory capacity (IC) were calculated from the FOT. Ventilation heterogeneity in acinar and conducting airways, and trapped gas (percent volume of trapped gas at functional residual capacity/vital capacity), were calculated from the MBNW. Measurements were repeated following methacholine. Methacholine-induced airway closure (percent change in forced vital capacity) and hyperinflation (change in IC) were also recorded. In 40 mild to moderate asthmatic patients, increase in Xrs5 after methacholine was predicted by increases in ventilation heterogeneity in acinar airways and forced vital capacity (r(2) = 0.37, P < 0.001), but had no correlation with ventilation heterogeneity in conducting airway increase or IC decrease. Increases in Rrs5 and Rrs5-Rrs19 after methacholine were not correlated with increases in ventilation heterogeneity, trapped gas, hyperinflation, or airway closure. Increased reactance in asthmatic patients after methacholine was indicative of heterogeneous changes in the lung periphery and airway closure. By contrast, increases in resistance and frequency dependence of resistance were not related to ventilation heterogeneity or airway closure and were more indicative of changes in central airway caliber than of heterogeneity. PMID:23372144

  11. Effect of technique and timing of tracheostomy in patients with acute traumatic spinal cord injury undergoing mechanical ventilation

    PubMed Central

    Ganuza, Javier Romero; Forcada, Angel Garcia; Gambarrutta, Claudia; De La Lastra Buigues, Elena Diez; Gonzalez, Victoria Eugenia Merlo; Fuentes, Fátima Paz; Luciani, Alejandro A.

    2011-01-01

    Objective To assess the effect of timing and techniques of tracheostomy on morbidity, mortality, and the burden of resources in patients with acute traumatic spinal cord injuries (SCIs) undergoing mechanical ventilation. Design Review of a prospectively collected database. Setting Intensive and intermediate care units of a monographic hospital for the treatment of SCI. Participants Consecutive patients admitted to the intensive care unit (ICU) during their first inpatient rehabilitation for cervical and thoracic traumatic SCI. A total of 323 patients were included: 297 required mechanical ventilation and 215 underwent tracheostomy. Outcome measures Demographic data, data relevant to the patients’ neurological injuries (level and grade of spinal cord damage), tracheostomy technique and timing, duration of mechanical ventilation, length of stay at ICU, incidence of pneumonia, incidence of perioperative and early postoperative complications, and mortality. Results Early tracheostomy (<7 days after orotracheal intubation) tracheostomy was performed in 101 patients (47%) and late (≥7 days) in 114 (53%). Surgical tracheostomy was employed in 119 cases (55%) and percutaneous tracheostomy in 96 (45%). There were 61 complications in 53 patients related to all tracheostomy procedures. Two were qualified as serious (tracheoesophageal fistula and mediastinal abscess). Other complications were mild. Bleeding was moderate in one case (late, percutaneous tracheostomy). Postoperative infection rate was low. Mortality of all causes was also low. Conclusion Early tracheostomy may have favorable effects in patients with acute traumatic SC. Both techniques, percutaneous and surgical tracheostomy, can be performed safely in the ICU. PMID:21528630

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

    PubMed Central

    2012-01-01

    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. PMID:22863373

  13. Long-term outcome in patients with Guillain-Barré syndrome requiring mechanical ventilation.

    PubMed

    Witsch, J; Galldiks, N; Bender, A; Kollmar, R; Bösel, J; Hobohm, C; Günther, A; Schirotzek, I; Fuchs, K; Jüttler, E

    2013-05-01

    We aimed to determine long-term disability and quality of life in patients with Guillain-Barré syndrome (GBS) who required mechanical ventilation (MV) in the acute phase. Our retrospective cohort study included 110 GBS patients admitted to an intensive care unit and requiring MV (01/1999-08/2010) in nine German tertiary academic medical centers. Outcome was determined 1 year or longer after hospital admission using the GBS disability scale, Barthel index (BI), EuroQuol-5D (EQ-5D) and Fatigue Severity Scale. Linear/multivariate regression analysis was used to analyze predicting factors for outcome. Mean time to follow up was 52.6 months. Hospital mortality was 5.5 % and long-term mortality 13.6 %. Overall 53.8 % had a favorable outcome (GBS disability score 0-1) and 73.7 % of survivors had no or mild disability (BI 90-100). In the five dimensions of the EQ-5D "mobility", "self-care", "usual activities", "pain" and "anxiety/depression" no impairments were stated by 50.6, 58.4, 36.4, 36.4 and 50.6 % of patients, respectively. A severe fatigue syndrome was present in 30.4 % of patients. Outcome was statistically significantly correlated with age, type of therapy and number of immunoglobulin courses. In GBS-patients requiring MV in the acute phase in-hospital, and long-term mortality are lower than that in previous studies, while long-term quality of life is compromised in a large fraction of patients, foremost by immobility and chronic pain. Efforts towards improved treatment approaches should address autonomic dysfunction to further reduce hospital mortality while improved rehabilitation concepts might ameliorate long-term disability. PMID:23299621

  14. Obesity might be a good prognosis factor for COPD patients using domiciliary noninvasive mechanical ventilation

    PubMed Central

    Altinoz, Hilal; Adiguzel, Nalan; Salturk, Cuneyt; Gungor, Gokay; Mocin, Ozlem; Berk Takir, Huriye; Kargin, Feyza; Balci, Merih; Dikensoy, Oner; Karakurt, Zuhal

    2016-01-01

    Cachexia is known to be a deteriorating factor for survival of patients with chronic obstructive pulmonary disease (COPD), but data related to obesity are limited. We observed that obese patients with COPD prescribed long-term noninvasive mechanical ventilation (NIMV) had better survival rate compared to nonobese patients. Therefore, we conducted a retrospective observational cohort study. Archives of Thoracic Diseases Training Hospital were sought between 2008 and 2013. All the subjects were prescribed domiciliary NIMV for chronic respiratory failure secondary to COPD. Subjects were grouped according to their body mass index (BMI). The first group consisted of subjects with BMI between 20 and 30 kg/m2, and the second group consisted of subjects with BMI >30 kg/m2. Data obtained at the first month’s visit for the following parameters were recorded: age, sex, comorbid diseases, smoking history, pulmonary function test, 6-minute walk test (6-MWT), and arterial blood gas analysis. Hospital admissions were recorded before and after the domiciliary NIMV usage. Mortality rate was searched from the electronic database. Overall, 118 subjects were enrolled. Thirty-eight subjects had BMI between 20 and 30 kg/m2, while 80 subjects had BMI >30 kg/m2. The mean age was 65.8±9.4 years, and 81% were male. The median follow-up time was 26 months and mortality rates were 32% and 34% for obese and nonobese subjects (P=0.67). Improvement in 6-MWT was protective against mortality. In conclusion, survival of obese patients with COPD using domiciliary NIMV was found to be better than those of nonobese patients, and the improvement in 6-MWT in such patients was found to be related to a better survival. PMID:27578969

  15. Obesity might be a good prognosis factor for COPD patients using domiciliary noninvasive mechanical ventilation.

    PubMed

    Altinoz, Hilal; Adiguzel, Nalan; Salturk, Cuneyt; Gungor, Gokay; Mocin, Ozlem; Berk Takir, Huriye; Kargin, Feyza; Balci, Merih; Dikensoy, Oner; Karakurt, Zuhal

    2016-01-01

    Cachexia is known to be a deteriorating factor for survival of patients with chronic obstructive pulmonary disease (COPD), but data related to obesity are limited. We observed that obese patients with COPD prescribed long-term noninvasive mechanical ventilation (NIMV) had better survival rate compared to nonobese patients. Therefore, we conducted a retrospective observational cohort study. Archives of Thoracic Diseases Training Hospital were sought between 2008 and 2013. All the subjects were prescribed domiciliary NIMV for chronic respiratory failure secondary to COPD. Subjects were grouped according to their body mass index (BMI). The first group consisted of subjects with BMI between 20 and 30 kg/m(2), and the second group consisted of subjects with BMI >30 kg/m(2). Data obtained at the first month's visit for the following parameters were recorded: age, sex, comorbid diseases, smoking history, pulmonary function test, 6-minute walk test (6-MWT), and arterial blood gas analysis. Hospital admissions were recorded before and after the domiciliary NIMV usage. Mortality rate was searched from the electronic database. Overall, 118 subjects were enrolled. Thirty-eight subjects had BMI between 20 and 30 kg/m(2), while 80 subjects had BMI >30 kg/m(2). The mean age was 65.8±9.4 years, and 81% were male. The median follow-up time was 26 months and mortality rates were 32% and 34% for obese and nonobese subjects (P=0.67). Improvement in 6-MWT was protective against mortality. In conclusion, survival of obese patients with COPD using domiciliary NIMV was found to be better than those of nonobese patients, and the improvement in 6-MWT in such patients was found to be related to a better survival. PMID:27578969

  16. Quantification of indoor VOCs in twenty mechanically ventilated buildings in Hong Kong

    NASA Astrophysics Data System (ADS)

    Chao, Christopher Y.; Chan, George Y.

    Information of volatile organic compounds (VOCs) in buildings in Hong Kong is relatively scared compared to other countries. Information of how much VOC accumulation comes from occupants themselves, from building materials and other outdoor sources are scarce even on a global basis. This study aimed at collecting information of the levels of individual VOCs using US-EPA Method TO-14. Twenty building premises including offices and public places such as customer service centers, shopping centers, etc. were studied. Samples were taken during the time slots when the mechanical ventilation system was operating. The 43 VOCs were grouped into three categories, i.e. aromatic hydrocarbons, chlorinated hydrocarbons and organohalogen. The most dominant VOCs found in the indoor samples were benzene, toluene, ethylbenzene, xylenes (BETX), chloroform and trichloroethylene as 100% of the samples were found to contain these VOCs. Besides, more than 75% of the samples were found to contain 1,3,5-trimethylbenzene, methylchloride and dichloromethane. The wt% of chlorinated hydrocarbons (48%) and the wt% of aromatic hydrocarbons (38%) only differed by about 10% in the office sector. Organohalogen (14%) contributed to the smallest fraction of the total on all the premises in the office sector on weight basis. A completely different distribution pattern was found in the non-office sector. The most abundant class of VOCs in terms of weight was aromatic hydrocarbons (80%). The second abundant class of VOCs was chlorinated hydrocarbons (14%) and was much less than the level of aromatic hydrocarbons in terms of weight. Organohalogen (6%) contributed to the smallest fraction of the total on all the premises in the non-office sector on weight basis.

  17. Sexuality in patients with noninvasive mechanical ventilation due to chronic respiratory failure.

    PubMed

    Schönhofer, B; Von Sydow, K; Bucher, T; Nietsch, M; Suchi, S; Köhler, D; Jones, P W

    2001-11-01

    In patients with chronic respiratory failure (CRF) noninvasive mechanical ventilation (NMV) improves quality of life. We studied some basic issues concerning sexuality in patients with NMV. In 383 patients with NMV for CRF (age, > 40 yr) physiologic data (lung function, blood gases, and exercise) were taken from within the 6 mo period before enrollment. The questionnaire was focused on sexuality after initiation of NMV. Of the patients, 54.3% sent back the questionnaire. NMV was used for 41.1 +/- 27.0 mo. A total of 34.1% of patients were sexually active. Compared with patients receiving NMV, control persons had a higher rate of sexual activity (84%, p < 0.0001) and masturbation rate (13 versus 40%). Sexually active patients had greater VC (2.1 versus 1.8 L), higher FEV(1) (1.4 versus 1.1 L), higher Pa(O(2)) at rest (64.0 versus 60.4 mm Hg), a higher maximal work load (72.0 versus 58.8 W), were younger, and most of them were married or had sexual partners. Changes in sexual activity after NMV initiation were reported to be as follows: "Nothing changed," 46.3%; "less active," 35.8%; "more active," 12.6%; and "fantasy increased," 10.5%. Increased sexual fantasy predominated in men. "Sexually active" patients with NMV had sexual intercourse 5.4 +/- 4.8 times per month. Sexuality in patients receiving NMV for CRF is markedly reduced compared with normal subjects. In half of the patients, sexual activity is influenced by initiation of NMV. PMID:11719298

  18. 15. NAVFAC Drawing 1,174,312(463AM4)(1970), 'Alterations for Laboratory FacilityHood VentilationMechanical' ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. NAVFAC Drawing 1,174,312(463A-M-4)(1970), 'Alterations for Laboratory Facility-Hood Ventilation-Mechanical' - Mare Island Naval Shipyard, Battery Test Office & Storage Facility, California Avenue & E Street, Vallejo, Solano County, CA

  19. Expiratory washout versus optimization of mechanical ventilation during permissive hypercapnia in patients with severe acute respiratory distress syndrome.

    PubMed

    Richecoeur, J; Lu, Q; Vieira, S R; Puybasset, L; Kalfon, P; Coriat, P; Rouby, J J

    1999-07-01

    The aim of this study was to compare three ventilatory techniques for reducing PaCO2 in patients with severe acute respiratory distress syndrome treated with permissive hypercapnia: (1) expiratory washout 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 without development of intrinsic positive end- expiratory pressure (PEEP) combined with a reduction of the instrumental dead space, and (3) the combination of both methods. Tidal volume was set according to the pressure-volume curve in order to obtain an inspiratory plateau airway pressure equal to the upper inflection point minus 2 cm H2O after setting the PEEP at 2 cm H2O above the lower inflection point and was kept constant throughout the study. The three modalities were compared at the same inspiratory plateau airway pressure through an adjustment of the extrinsic PEEP. During conventional mechanical ventilation using a respiratory frequency of 18 breaths/min, respiratory acidosis (PaCO2 = 84 +/- 24 mm Hg and pH = 7.21 +/- 0.12) was observed. Expiratory washout and optimized mechanical ventilation (respiratory frequency of 30 +/- 4 breaths/min) had similar effects on CO2 elimination (DeltaPaCO2 = -28 +/- 11% versus -27 +/- 12%). A further decrease in PaCO2 was observed when both methods were combined (DeltaPaCO2 = -46 +/- 7%). Extrinsic PEEP had to be reduced by 5.3 +/- 2.1 cm H2O during expiratory washout and by 7.3 +/- 1.3 cm H2O during the combination of the two modes, whereas it remained unchanged during optimized mechanical ventilation alone. In conclusion, increasing respiratory rate and reducing instrumental dead space during conventional mechanical ventilation is as efficient as expiratory washout to reduce PaCO2 in patients with severe ARDS and permissive hypercapnia. When used in combination, both techniques have additive effects and result in PaCO2 levels close to normal values. PMID:10390383

  20. Recent advances in mechanical ventilation in patients with acute respiratory distress syndrome.

    PubMed

    Rittayamai, Nuttapol; Brochard, Laurent

    2015-03-01

    Acute respiratory distress syndrome (ARDS) is characterised by different degrees of severity and different stages. Understanding these differences can help to better adapt the ventilatory settings to protect the lung from ventilator-induced lung injury by reducing hyperinflation or keeping the lung open when it is possible. The same therapies may be useful and beneficial in certain forms of ARDS, and risky or harmful at other stages: this includes high positive end-expiratory pressure, allowance of spontaneous breathing activity or use of noninvasive ventilation. The severity of the disease is the primary indicator to individualise treatment. Monitoring tools such as oesophageal pressure or lung volume measurements may also help to set the ventilator. At an earlier stage, an adequate lung protective strategy may also help to prevent the development of ARDS. PMID:25726563

  1. Nebulized heparin for patients under mechanical ventilation: an individual patient data meta-analysis.

    PubMed

    Glas, Gerie J; Serpa Neto, Ary; Horn, Janneke; Cochran, Amalia; Dixon, Barry; Elamin, Elamin M; Faraklas, Iris; Dissanaike, Sharmila; Miller, Andrew C; Schultz, Marcus J

    2016-12-01

    Pulmonary coagulopathy is a characteristic feature of lung injury including ventilator-induced lung injury. The aim of this individual patient data meta-analysis is to assess the effects of nebulized anticoagulants on outcome of ventilated intensive care unit (ICU) patients. A systematic search of PubMed (1966-2014), Scopus, EMBASE, and Web of Science was conducted to identify relevant publications. Studies evaluating nebulization of anticoagulants in ventilated patients were screened for inclusion, and corresponding authors of included studies were contacted to provide individual patient data. The primary endpoint was the number of ventilator-free days and alive at day 28. Secondary endpoints included hospital mortality, ICU- and hospital-free days at day 28, and lung injury scores at day seven. We constructed a propensity score-matched cohort for comparisons between patients treated with nebulized anticoagulants and controls. Data from five studies (one randomized controlled trial, one open label study, and three studies using historical controls) were included in the meta-analysis, compassing 286 patients. In all studies unfractionated heparin was used as anticoagulant. The number of ventilator-free days and alive at day 28 was higher in patients treated with nebulized heparin compared to patients in the control group (14 [IQR 0-23] vs. 6 [IQR 0-22]), though the difference did not reach statistical significance (P = 0.459). The number of ICU-free days and alive at day 28 was significantly higher, and the lung injury scores at day seven were significantly lower in patients treated with nebulized heparin. In the propensity score-matched analysis, there were no differences in any of the endpoints. This individual patient data meta-analysis provides no convincing evidence for benefit of heparin nebulization in intubated and ventilated ICU patients. The small patient numbers and methodological shortcomings of included studies underline the need for high

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

    PubMed Central

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

    2013-01-01

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

  3. Combined effects of ventilation mode and positive end-expiratory pressure on mechanics, gas exchange and the epithelium in mice with acute lung injury.

    PubMed

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

    2013-01-01

    The accepted protocol to ventilate patients with acute lung injury is to use low tidal volume (V(T)) in combination with recruitment maneuvers or positive end-expiratory pressure (PEEP). However, an important aspect of mechanical ventilation has not been considered: the combined effects of PEEP and ventilation modes on the integrity of the epithelium. Additionally, it is implicitly assumed that the best PEEP-V(T) combination also protects the epithelium. We aimed to investigate the effects of ventilation mode and PEEP on respiratory mechanics, peak airway pressures and gas exchange as well as on lung surfactant and epithelial cell integrity in mice with acute lung injury. HCl-injured mice were ventilated at PEEPs of 3 and 6 cmH(2)O with conventional ventilation (CV), CV with intermittent large breaths (CV(LB)) to promote recruitment, and a new mode, variable ventilation, optimized for mice (VV(N)). Mechanics and gas exchange were measured during ventilation and surfactant protein (SP)-B, proSP-B and E-cadherin levels were determined from lavage and lung homogenate. PEEP had a significant effect on mechanics, gas exchange and the epithelium. The higher PEEP reduced lung collapse and improved mechanics and gas exchange but it also down regulated surfactant release and production and increased epithelial cell injury. While CV(LB) was better than CV, VV(N) outperformed CV(LB) in recruitment, reduced epithelial injury and, via a dynamic mechanotransduction, it also triggered increased release and production of surfactant. For long-term outcome, selection of optimal PEEP and ventilation mode may be based on balancing lung physiology with epithelial injury. PMID:23326543

  4. Development of an Outdoor Temperature Based Control Algorithm for Residential Mechanical Ventilation Control

    SciTech Connect

    Less, Brennan; Walker, Iain; Tang, Yihuan

    2014-08-01

    The Incremental Ventilation Energy (IVE) model developed in this study combines the output of simple air exchange models with a limited set of housing characteristics to estimate the associated change in energy demand of homes. The IVE model was designed specifically to enable modellers to use existing databases of housing characteristics to determine the impact of ventilation policy change on a population scale. The IVE model estimates of energy change when applied to US homes with limited parameterisation are shown to be comparable to the estimates of a well-validated, complex residential energy model.

  5. Research on Heat-Mechanical Coupling of Ventilated Disc Brakes under the Condition of Emergency Braking

    NASA Astrophysics Data System (ADS)

    Tan, Xuelong; Zhang, Jian; Tang, Wenxian; Zhang, Yang

    Taking the ventilated disc brake in some company as research object, and using UG to build 3D models of brake disc and pad, and making use of ABAQUS/Standard to set up two parts' finite element model, via the decelerated motion of actual simulation brake disc, which gets ventilated disc brake in the case of emergency breaking in time and space distribution of conditions of temperature and stress field, summarizes the distribution of temperature field and stress field, proves complex coupling between temperature, stress, and supplies the direct basis for brake's fatigue life analysis.

  6. Protocolized Sedation versus Usual Care in Pediatric Patients Mechanically Ventilated for Acute Respiratory Failure: A Randomized Clinical Trial

    PubMed Central

    Curley, Martha A.Q.; Wypij, David; Watson, R. Scott; Grant, Mary Jo C.; Asaro, Lisa A.; Cheifetz, Ira M.; Dodson, Brenda; Franck, Linda S.; Gedeit, Rainer G.; Angus, Derek C.; Matthay, Michael A.

    2016-01-01

    Importance Protocolized sedation improves clinical outcomes in critically-ill adults, but its effect in children is unknown. Objective To determine whether critically-ill children managed with a nurse-implemented, goal-directed sedation protocol (RESTORE) would experience fewer days of mechanical ventilation than patients receiving usual care. Design, Setting, and Participants Cluster-randomized trial conducted in 31 U.S. Pediatric Intensive Care Units (PICUs). Children (n=2449; mean age 4.7 years, range 2 weeks to 17 years) mechanically ventilated for acute respiratory failure were enrolled 2009–2013 and followed until 72 hours after opioids were discontinued, 28 days, or hospital discharge. Interventions Intervention PICUs (17 sites, n=1225 patients) managed sedation using a protocol that included targeted sedation, arousal assessments, extubation readiness testing, sedation adjustment every 8 hours, and sedation weaning. Control PICUs (14 sites, n=1224 patients) managed sedation per usual care without a protocol. Main Outcome and Measures The primary outcome was duration of mechanical ventilation. Secondary outcomes included time to recovery from acute respiratory failure, duration of weaning from mechanical ventilation, neurological testing, PICU and hospital lengths of stay, in-hospital mortality, sedation-related adverse events, sedative exposure including measures of wakefulness, pain, and agitation, and occurrence of iatrogenic withdrawal. Results Duration of mechanical ventilation was not statistically significantly different between the two groups (median; interquartile range: intervention: 6.5 days; 4.1–11.2 vs. control: 6.5; 3.7–12.1). Sedation-related adverse events including inadequate pain and sedation management, clinically significant iatrogenic withdrawal, and unplanned endotracheal tube/invasive line removal were not statistically significantly different between the two groups. Intervention patients experienced more post-extubation stridor

  7. Effect of salmeterol/fluticasone combination on the dynamic changes of lung mechanics in mechanically ventilated COPD patients: a prospective pilot study

    PubMed Central

    Chen, Wei-Chih; Chen, Hung-Hsing; Chiang, Chi-Huei; Lee, Yu-Chin; Yang, Kuang-Yao

    2016-01-01

    Background The combined therapy of inhaled corticosteroids and long-acting beta-2 agonists for mechanically ventilated patients with COPD has never been explored. Therefore, the aim of this study was to investigate their dynamic effects on lung mechanics and gas exchange. Materials and methods Ten mechanically ventilated patients with resolution of the causes of acute exacerbations of COPD were included. Four puffs of salmeterol 25 μg/fluticasone 125 μg combination therapy were administered. Lung mechanics, including maximum resistance of the respiratory system (Rrs), end-inspiratory static compliance, peak inspiratory pressure (PIP), plateau pressure, and mean airway pressure along with gas exchange function were measured and analyzed. Results Salmeterol/fluticasone produced a significant improvement in Rrs and PIP after 30 minutes. With regard to changes in baseline values, salmeterol/fluticasone inhalation had a greater effect on PIP than Rrs. However, the therapeutic effects seemed to lose significance after 3 hours of inhaled corticosteroid/long-acting beta-2 agonist administration. Conclusion The combination of salmeterol/fluticasone-inhaled therapy in mechanically ventilated patients with COPD had a significant benefit in reducing Rrs and PIP. PMID:26869782

  8. Comparison of Dexmedetomidine, Propofol and Midazolam for Short-Term Sedation in Postoperatively Mechanically Ventilated Neurosurgical Patients

    PubMed Central

    Agrawal, Sanjay; Kumar, Sanjay; Mishra, Abhishek; Sharma, Sunil; Kumar, Raj

    2014-01-01

    Background: Effective management of analgesia and sedation in the intensive care unit depends on the needs of the patient, subjective and/or objective measurement and drug titration to achieve specific endpoints. Aim: The present study compared the efficacy of dexmedetomidine, propofol and midazolam for sedation in neurosurgical patients for postoperative mechanical ventilation. Materials and Methods: Ninety patients aged 20-65 years, ASA physical status I to III, undergoing neurosurgery and requiring postoperative ventilation were included. The patients were randomly divided into three groups of 30 each. Group D received dexmedetomidine 1 mcg/kg over 15 minutes as a loading dose, followed by 0.4-0.7 mcg/kg/h. Group P received propofol 1 mg/kg over 15 minutes as a loading dose, followed by 1-3 mg/kg/h. Group M received midazolam 0.04 mg/kg over 15 minutes as a loading dose, followed by 0.08 mg/kg/h. Measurements: Heart rate, mean arterial pressure, sedation level, fentanyl requirement, ventilation and extubation time were recorded. Results: Adequate sedation level was achieved with all three agents. Dexmedetomidine group required less fentanyl for postoperative analgesia. In group D there was a decrease in HR after dexmedetomidine infusion (p<0.05), but there was no significant difference in HR between group P and group M. After administration of study drug there was a significant decrease in MAP comparison to baseline value in all groups at all time intervals (p<0.05), except postextubation period (p>0.05). Extubation time was lowest in group P (p<0.05). Conclusion: Dexmedetomidine is safer and equally effective agent compared to propofol and midazolam for sedation of neurosurgical mechanically ventilated patients with good hemodynamic stability and extubation time as rapid as propofol. Dexmedetomidine also reduced postoperative fentanyl requirements. PMID:25386451

  9. Heat-rekindling in UVB-irradiated skin above NGF-sensitized muscle: experimental models of prolonged mechanical hypersensitivity.

    PubMed

    Vecchio, Silvia Lo; Finocchietti, Sara; Gazerani, Parisa; Petersen, Lars J; Arendt-Nielsen, Lars; Graven-Nielsen, Thomas

    2014-01-01

    Experimental models of prolonged pain hypersensitivity in humans are desirable for screening novel analgesic compounds. In this study, heat stimuli were applied in ultraviolet-B (UVB)-irradiated skin and in the UVB-irradiated skin combined with nerve growth factor (NGF)-injected muscle to investigate 1) whether the evoked mechanical hypersensitivity by UVB irradiation would be prolonged or enhanced following heat rekindling, and 2) whether the combination between cutaneous and muscle hypersensitivity may influence the rekindling effects. Skin sensitization was induced in 25 volunteers by UVB irradiation in areas above the upper-trapezius muscle, low-back or forearm. Muscle sensitization was induced in the low back by bilateral injections of NGF. The area of cutaneous hyperalgesia was evaluated 3 days after the irradiation by mechanical pin-prick stimulation whereas the areas of allodynia were evaluated 1, 2 and 3 days after irradiation by von Frey hair assessments. Cutaneous heat stimulation (40°C for 5 min) was performed on the 3(rd) day to investigate its effect on the areas of cutaneous allodynia and hyperalgesia. Findings revealed that 1) allodynia and hyperalgesia developed following UVB irradiation, 2) heat stimulation of the UVB-irradiated skin enlarged both hyperalgesic and allodynic areas (P < 0.01), and 3) muscle sensitization did not influence the effect of UVB on allodynia or the response to heat rekindling. These data suggest that heat rekindling applied to an UVB-sensitized skin can maintain or facilitate allodynia and hyperalgesia for a longer period offering a suitable model for testing analgesic compounds when sufficient duration of time is needed for investigation of drug efficacy. PMID:25349637

  10. Synchronized Nasal Intermittent Positive Pressure Ventilation of the Newborn: Technical Issues and Clinical Results.

    PubMed

    Moretti, Corrado; Gizzi, Camilla; Montecchia, Francesco; Barbàra, Caterina Silvia; Midulla, Fabio; Sanchez-Luna, Manuel; Papoff, Paola

    2016-01-01

    Although mechanical ventilation via an endotracheal tube has undoubtedly led to improvement in neonatal survival in the last 40 years, the prolonged use of this technique may predispose the infant to development of many possible complications including bronchopulmonary dysplasia. Avoiding mechanical ventilation is thought to be a critical goal, and different modes of noninvasive respiratory support beyond nasal continuous positive airway pressure, such as nasal intermittent positive pressure ventilation and synchronized nasal intermittent positive pressure ventilation, are also available and may reduce intubation rate. Several trials have demonstrated that the newer modes of noninvasive ventilation are more effective than nasal continuous positive airway pressure in reducing extubation failure and may also be more helpful as modes of primary support to treat respiratory distress syndrome after surfactant and for treatment of apnea of prematurity. With synchronized noninvasive ventilation, these benefits are more consistent, and different modes of synchronization have been reported. Although flow-triggering is the most common mode of synchronization, this technique is not reliable for noninvasive ventilation in neonates because it is affected by variable leaks at the mouth and nose. This review discusses the mechanisms of action, benefits and limitations of noninvasive ventilation, describes the different modes of synchronization and analyzes the technical characteristics, properties and clinical results of a flow-sensor expressly developed for synchronized noninvasive ventilation. PMID:27251453

  11. Role of oral care to prevent VAP in mechanically ventilated Intensive Care Unit patients

    PubMed Central

    Gupta, A; Gupta, A; Singh, TK; Saxsena, A

    2016-01-01

    Ventilator associated pneumonia (VAP) is the most common nosocomial infection in Intensive Care Unit. One major factor causing VAP is the aspiration of oral colonization because of poor oral care practices. We feel the role of simple measure like oral care is neglected, despite the ample evidence of it being instrumental in preventing VAP. PMID:26955317

  12. Does the use of primary continuous positive airway pressure reduce the need for intubation and mechanical ventilation in infants ≤32 weeks’ gestation?

    PubMed Central

    Yee, Wendy H; Scotland, Jeanne; Pham, Yung; Finch, Robert

    2011-01-01

    BACKGROUND: Ventilator-induced lung injury is a recognized risk factor for bronchopulmonary dysplasia. OBJECTIVE: To determine whether primary continuous positive airway pressure (CPAP), defined as CPAP without previous endotracheal intubation for any indication, can reduce the need for intubation and mechanical ventilation in infants born at ≤32 weeks’ gestational age. METHODS: The literature was reviewed using the methodology for systematic reviews for the Consensus on Resuscitation Science adapted from the American Heart Association’s International Liaison Committee on Resuscitation. RESULTS: Fourteen studies were reviewed. Eleven studies provided varying degrees of supportive evidence (level of evidence 3 to 4) that the use of primary CPAP can reduce the need for intubation and mechanical ventilation. CONCLUSION: The use of CPAP as a primary intervention and mode of respiratory support is an option for infants ≤32 weeks’ gestation, but avoidance of intubation and mechanical ventilation is more likely in mature infants >27 weeks’ gestation. PMID:23204903

  13. Prolonged secretion of cortisol as a possible mechanism underlying stress and depressive behaviour.

    PubMed

    Qin, Dong-Dong; Rizak, Joshua; Feng, Xiao-Li; Yang, Shang-Chuan; Lü, Long-Bao; Pan, Lei; Yin, Yong; Hu, Xin-Tian

    2016-01-01

    Stress is associated with the onset of depressive episodes, and cortisol hypersecretion is considered a biological risk factor of depression. However, the possible mechanisms underlying stress, cortisol and depressive behaviours are inconsistent in the literature. This study examined the interrelationships among stress, cortisol and observed depressive behaviours in female rhesus macaques for the first time and explored the possible mechanism underlying stress and depressive behaviour. Female monkeys were video-recorded, and the frequencies of life events and the duration of huddling were analysed to measure stress and depressive behaviour. Hair samples were used to measure chronic cortisol levels, and the interactions between stress and cortisol in the development of depressive behaviour were further evaluated. Significant correlations were found between stress and depressive behaviour measures and between cortisol levels and depressive behaviour. Stress was positively correlated with cortisol levels, and these two factors interacted with each other to predict the monkeys' depressive behaviours. This finding extends the current understanding of stress/cortisol interactions in depression, especially pertaining to females. PMID:27443987

  14. Clear evidence of mechanical deformation in RF-MEMS switches during prolonged actuation

    NASA Astrophysics Data System (ADS)

    Mulloni, V.; Resta, G.; Margesin, B.

    2014-07-01

    Dielectric charging is normally considered one of the most important problems when dealing with RF-MEMS switch reliability, especially for applications which require long-term operation. Other important effects are therefore often neglected. In this paper we demonstrate that, for the case of long-term actuation in dielectric-less switches, the most important issue for switch reliability is not dielectric charging but viscoelastic deformation and creep of the mobile membrane. The measurements and the analysis are performed both for a cantilever and for a clamped-clamped switch configuration, evidencing that in the first case the mechanical deformations are more pronounced, and that they can justify almost completely the variation of actuation and release voltage experimentally measured. Mechanical deformation is also detected in a clamped-clamped switch, but it is less evident than that in the previous case. Nonetheless, even in this case they are responsible for most of the actuation and de-actuation voltage change experimentally detected.

  15. Prolonged secretion of cortisol as a possible mechanism underlying stress and depressive behaviour

    PubMed Central

    Qin, Dong-dong; Rizak, Joshua; Feng, Xiao-li; Yang, Shang-chuan; Lü, Long-bao; Pan, Lei; Yin, Yong; Hu, Xin-tian

    2016-01-01

    Stress is associated with the onset of depressive episodes, and cortisol hypersecretion is considered a biological risk factor of depression. However, the possible mechanisms underlying stress, cortisol and depressive behaviours are inconsistent in the literature. This study examined the interrelationships among stress, cortisol and observed depressive behaviours in female rhesus macaques for the first time and explored the possible mechanism underlying stress and depressive behaviour. Female monkeys were video-recorded, and the frequencies of life events and the duration of huddling were analysed to measure stress and depressive behaviour. Hair samples were used to measure chronic cortisol levels, and the interactions between stress and cortisol in the development of depressive behaviour were further evaluated. Significant correlations were found between stress and depressive behaviour measures and between cortisol levels and depressive behaviour. Stress was positively correlated with cortisol levels, and these two factors interacted with each other to predict the monkeys’ depressive behaviours. This finding extends the current understanding of stress/cortisol interactions in depression, especially pertaining to females. PMID:27443987

  16. A simplified model for estimating population-scale energy impacts of building envelope air-tightening and mechanical ventilation retrofits

    SciTech Connect

    Logue, Jennifer M.; Turner, William J. N.; Walker, Iain S.; Singer, Brett C.

    2015-01-19

    Changing the air exchange rate of a home (the sum of the infiltration and mechanical ventilation airflow rates) affects the annual thermal conditioning energy. Large-scale changes to air exchange rates of the housing stock can significantly alter the residential sector's energy consumption. However, the complexity of existing residential energy models is a barrier to the accurate quantification of the impact of policy changes on a state or national level. The Incremental Ventilation Energy (IVE) model developed in this study combines the output of simple air exchange models with a limited set of housing characteristics to estimate the associated change in energy demand of homes. The IVE model was designed specifically to enable modellers to use existing databases of housing characteristics to determine the impact of ventilation policy change on a population scale. The IVE model estimates of energy change when applied to US homes with limited parameterisation are shown to be comparable to the estimates of a well-validated, complex residential energy model.

  17. 13CO2 recovery fraction in expired air of septic patients under mechanical ventilation.

    PubMed

    Auxiliadora-Martins, M; Martins, M A; Coletto, F A; Martins-Filho, O A; Marchini, J S; Basile-Filho, A

    2008-07-01

    The continuous intravenous administration of isotopic bicarbonate (NaH13CO2) has been used for the determination of the retention of the 13CO2 fraction or the 13CO2 recovered in expired air. This determination is important for the calculation of substrate oxidation. The aim of the present study was to evaluate, in critically ill patients with sepsis under mechanical ventilation, the 13CO2 recovery fraction in expired air after continuous intravenous infusion of NaH13CO2 (3.8 micromol/kg diluted in 0.9% saline in ddH2O). A prospective study was conducted on 10 patients with septic shock between the second and fifth day of sepsis evolution (APACHE II, 25.9 +/- 7.4). Initially, baseline CO2 was collected and indirect calorimetry was also performed. A primer of 5 mL NaH13CO2 was administered followed by continuous infusion of 5 mL/h for 6 h. Six CO2 production (VCO2) measurements (30 min each) were made with a portable metabolic cart connected to a respirator and hourly samples of expired air were obtained using a 750-mL gas collecting bag attached to the outlet of the respirator. 13CO2 enrichment in expired air was determined with a mass spectrometer. The patients presented a mean value of VCO2 of 182 +/- 52 mL/min during the steady-state phase. The mean recovery fraction was 0.68 +/- 0.06%, which is less than that reported in the literature (0.82 +/- 0.03%). This suggests that the 13CO2 recovery fraction in septic patients following enteral feeding is incomplete, indicating retention of 13CO2 in the organism. The severity of septic shock in terms of the prognostic index APACHE II and the sepsis score was not associated with the 13CO2 recovery fraction in expired air. PMID:18719737

  18. Central Fan Integrated Ventilation Systems

    SciTech Connect

    2009-05-12

    This information sheet describes one example of a ventilation system design, a central fan integrated supply (CFIS) system, a mechanical ventilation and pollutant source control to ensure that there is reasonable indoor air quality inside the house.

  19. Alpha-2 agonists for sedation of mechanically ventilated adults in intensive care units: a systematic review.

    PubMed Central

    Cruickshank, Moira; Henderson, Lorna; MacLennan, Graeme; Fraser, Cynthia; Campbell, Marion; Blackwood, Bronagh; Gordon, Anthony; Brazzelli, Miriam

    2016-01-01

    BACKGROUND Care of critically ill patients in intensive care units (ICUs) often requires potentially invasive or uncomfortable procedures, such as mechanical ventilation (MV). Sedation can alleviate pain and discomfort, provide protection from stressful or harmful events, prevent anxiety and promote sleep. Various sedative agents are available for use in ICUs. In the UK, the most commonly used sedatives are propofol (Diprivan(®), AstraZeneca), benzodiazepines [e.g. midazolam (Hypnovel(®), Roche) and lorazepam (Ativan(®), Pfizer)] and alpha-2 adrenergic receptor agonists [e.g. dexmedetomidine (Dexdor(®), Orion Corporation) and clonidine (Catapres(®), Boehringer Ingelheim)]. Sedative agents vary in onset/duration of effects and in their side effects. The pattern of sedation of alpha-2 agonists is quite different from that of other sedatives in that patients can be aroused readily and their cognitive performance on psychometric tests is usually preserved. Moreover, respiratory depression is less frequent after alpha-2 agonists than after other sedative agents. OBJECTIVES To conduct a systematic review to evaluate the comparative effects of alpha-2 agonists (dexmedetomidine and clonidine) and propofol or benzodiazepines (midazolam and lorazepam) in mechanically ventilated adults admitted to ICUs. DATA SOURCES We searched major electronic databases (e.g. MEDLINE without revisions, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE and Cochrane Central Register of Controlled Trials) from 1999 to 2014. METHODS Evidence was considered from randomised controlled trials (RCTs) comparing dexmedetomidine with clonidine or dexmedetomidine or clonidine with propofol or benzodiazepines such as midazolam, lorazepam and diazepam (Diazemuls(®), Actavis UK Limited). Primary outcomes included mortality, duration of MV, length of ICU stay and adverse events. One reviewer extracted data and assessed the risk of bias of included trials. A second reviewer cross-checked all the

  20. Prolonged noxious mechanical stimulation of the rat's tail: responses and encoding properties of dorsal horn neurones.

    PubMed Central

    Cervero, F; Handwerker, H O; Laird, J M

    1988-01-01

    1. Single-unit electrical activity has been recorded from dorsal horn neurones in the sacral (S1-S2) segments of the spinal cord of barbiturate-anaesthetized rats. Fifty-two neurones responding to a manually applied pinch of their receptive fields in the tail were selected. They were subsequently tested for their responses to four successive 2 min pinches at noxious intensities delivered by a feed-back-controlled mechanical device. 2. Neurones were tested with both innocuous (i.e. brushing and stroking) and noxious (i.e. pinching, pin-prick, and in some cases heating about 45 degrees C) stimulation of their cutaneous receptive fields. Three of the tested cells were driven exclusively by innocuous skin stimulation (mechanoreceptive or class 1), thirty-six were driven by both innocuous and noxious skin stimulation (multireceptive or class 2) and thirteen were driven exclusively by noxious skin stimulation (nocireceptive or class 3). 3. All of the multireceptive and nocireceptive neurones responded to the 2 min noxious pinch with an initial phasic discharge followed by sustained firing that showed little evidence of adaptation throughout the stimulus period. The three mechanoreceptive neurones responded to the 2 min noxious pinch with a short discharge at the stimulus onset, but were silent for the remainder of the stimulus period. 4. Thirty-one cells were tested with successive 2 min pinches of 4, 6 and 8 N (and in some cases, a further 4 N pinch) applied at 10 min intervals. Different encoding properties were observed during the sustained part of the neuronal response according to: (i) the afferent fibre input characteristics of the cell; (ii) whether or not the tail had received a test series of pinches earlier in the same experiment. 5. None of the multireceptive cells with only an A-fibre afferent input encoded the stimulus strength. However, the multireceptive cells with both an A- and a C-fibre afferent input and all nocireceptive cells did encode the stimulus

  1. Evaluation of the Effect of Nebulized N-Acetylcysteine on Respiratory Secretions in Mechanically Ventilated Patients: Randomized Clinical Trial

    PubMed Central

    Masoompour, Seyed Masoom; Anushiravani, Amir; Tafaroj Norouz, Amir

    2015-01-01

    Background The purpose of our study was to evaluate an inexpensive and available method to reduce mucous impactions in mechanically ventilated patients. Methods This randomized clinical trial was conducted on 40 mechanically ventilated patients aged 15-90 years. The patients were randomly allocated into two arms; 20 cases and 20 controls. The cases received N-acetylcysteine via their nebulizers, and the control group received normal saline three times a day for one day. We measured the density of respiratory secretion, plateau and peak airway pressures, and O2 saturation at baseline, 12 and 24 hours later. Results Although the mean secretion density was significantly lower in the NAC group (F (1, 38)=8.61, P=0.006), but a repeated measures ANOVA with a Greenhouse-Geisser correction determined that the effect of NAC on mean secretion density did not differ significantly between time points (F (1, 38)=3.08, P=0.087). NAC increased O2 saturation significantly between time points (F (1.92, 73.1)=4.6, P=0.014). The plateau airway pressures were relatively stable throughout the study in the normal saline and NAC groups (F (1.95, 37.1)=0.67, P=0.513). The peak airway pressure did not change significantly during the study in the normal saline and NAC groups (F (1.52, 56.4)=0.91, P=0.384). Conclusion Considering the limitations of the study, nebulized NAC in mechanically ventilated patients was not effective more than normal saline nebulization in reducing the density of mucous plugs. The peak and plateau airway pressures were relatively stable throughout the study in both groups. Trial Registration Number: IRCT201104276312N1. PMID:26170516

  2. The effect of open and closed endotracheal tube suctioning system on respiratory parameters of infants undergoing mechanical ventilation

    PubMed Central

    Taheri, Parvin; Asgari, Narges; Mohammadizadeh, Majid; Golchin, Mehri

    2012-01-01

    Aims: Mechanical ventilation is used for some infants in neonatal intensive care units (NICU) due to many physiological and clinical causes. Since these patients have endotracheal tubes, cleaning and keeping the airways open through suctioning should be done to increase oxygenation. This study aimed to evaluate effect of open and closed suctioning methods on respiratory parameters of infants undergoing mechanical ventilation. Materials and Methods: In this crossover clinical trial, 44 infants were selected among those undergone mechanical ventilation in NICU of Isfahan's Al-Zahra Hospital using convenience sampling method. The subjects were randomly divided into two groups. In the first group, open suctioning was carried out and after three hours of cleaning, closed suctioning was done. In the second group, closed suctioning was firstly done and following three hours of cleaning, open suctioning was implemented. Respiratory rate (RR) and percentage of arterial blood oxygen saturation was measured before, during and after each type of suctioning. Data were analyzed using repeated measures ANOVA and independent student's t-test. Findings: There was a significant difference between mean respiratory rate and arterial blood oxygen saturation in infants before, during and after the closed and open suctioning. The percentage of arterial blood oxygen saturation had a significant reduction in open method compared to closed method during suctioning and immediately after it. RR three minutes after suctioning showed a significant reduction in both steps in open method compared to closed method. Conclusions: Close method caused fewer changes in hemodynamic status of infants. Therefore, in order to prevent respiratory complications in infants, nurses are recommended to perform the endotracheal tube suctioning by closed method. PMID:23493041

  3. Computer simulation allows goal-oriented mechanical ventilation in acute respiratory distress syndrome

    PubMed Central

    Uttman, Leif; Ögren, Helena; Niklason, Lisbet; Drefeldt, Björn; Jonson, Björn

    2007-01-01

    Introduction To prevent further lung damage in patients with acute respiratory distress syndrome (ARDS), it is important to avoid overdistension and cyclic opening and closing of atelectatic alveoli. Previous studies have demonstrated protective effects of using low tidal volume (VT), moderate positive end-expiratory pressure and low airway pressure. Aspiration of dead space (ASPIDS) allows a reduction in VT by eliminating dead space in the tracheal tube and tubing. We hypothesized that, by applying goal-orientated ventilation based on iterative computer simulation, VT can be reduced at high respiratory rate and much further reduced during ASPIDS without compromising gas exchange or causing high airway pressure. Methods ARDS was induced in eight pigs by surfactant perturbation and ventilator-induced lung injury. Ventilator resetting guided by computer simulation was then performed, aiming at minimal VT, plateau pressure 30 cmH2O and isocapnia, first by only increasing respiratory rate and then by using ASPIDS as well. Results VT decreased from 7.2 ± 0.5 ml/kg to 6.6 ± 0.5 ml/kg as respiratory rate increased from 40 to 64 ± 6 breaths/min, and to 4.0 ± 0.4 ml/kg when ASPIDS was used at 80 ± 6 breaths/min. Measured values of arterial carbon dioxide tension were close to predicted values. Without ASPIDS, total positive end-expiratory pressure and plateau pressure were slightly higher than predicted, and with ASPIDS they were lower than predicted. Conclusion In principle, computer simulation may be used in goal-oriented ventilation in ARDS. Further studies are needed to investigate potential benefits and limitations over extended study periods. PMID:17352801

  4. Indoor ozone concentrations: Ventilation rate impacts and mechanisms of outdoor concentration attenuation

    SciTech Connect

    Cano-Ruiz, J.A.; Modera, M.P.; Nazaroff, W.W.

    1992-07-01

    The classification of outdoor (ambient) air as fresh for the purposes of ventilation is not always appropriate, particularly in urban areas. In many cities of the world, urban air frequently violates health-based air quality standards due to high ozone concentrations. The degree of protection from exposure to ozone offered by the indoor environment depends on the relationship between indoor and outdoor ozone levels. Existing concentration data indicates that indoor/outdoor ozone ratios range between 10 and 80%. This paper analyzes several of the key issues influencing indoor ozone concentrations, including: (1) the degree of penetration of outdoor ozone indoors, (2) removal within the indoor environment (removal at surfaces and within air distribution systems), and (3) the correlation in time between outdoor ozone levels and ventilation rates. A model for calculating the degree of ozone removal in typical building leaks and air distribution systems is described and applied to a range of typical cases. This model indicates that the degree of removal is minimal for most wooden building cracks, but could be significant in leaks in concrete or brick structures, and is strongly dependent on the lining material for air distribution systems. Indoor ozone exposure estimates based on hourly outdoor ozone monitoring data and hour-by-hour weather-based simulations of infiltration rates and building operation are reported for a few residential scenarios. These estimates serve as a basis for exploring the impact of energy-efficient ventilation strategies on indoor ozone exposures.

  5. Air compressor battery duration with mechanical ventilation in a field anesthesia machine.

    PubMed

    Szpisjak, Dale F; Giberman, Anthony A

    2015-05-01

    Compressed air to power field anesthesia machine ventilators may be supplied by air compressor with battery backup. This study determined the battery duration when the compPAC ventilator's air compressor was powered by NiCd battery to ventilate the Vent Aid Training Test Lung modeling high (HC = 0.100 L/cm H2O) and low (LC = 0.020 L/cm H2O) pulmonary compliance. Target tidal volumes (VT) were 500, 750, and 1,000 mL. Respiratory rate = 10 bpm, inspiratory-to-expiratory time ratio = 1:2, and fresh gas flow = 1 L/min air. N = 5 in each group. Control limits were determined from the first 150 minutes of battery power for each run and lower control limit = mean VT - 3SD. Battery depletion occurred when VT was below the lower control limit. Battery duration ranged from 185.8 (±3.2) minutes in the LC-1000 group to 233.3 (±3.6) minutes in the HC-750 group. Battery duration of the LC-1000 group was less than all others (p = 0.027). The differences among the non-LC-1000 groups were not clinically significant. PMID:25939102

  6. Need for Mechanical Ventilation in Pediatric Scald Burns: Why it Happens and Why it Matters.

    PubMed

    Mosier, Michael J; Peter, Tony; Gamelli, Richard L

    2016-01-01

    Scald burns are the most common thermal injury among children. A small subset of pediatric scald burns are complicated by the need for mechanical ventilation (MV). Studies suggest that 4 to 5% of pediatric scald burns will require MV, and these patients tend to be younger with larger burns. Identifying why pediatric patients with scald burns require MV has remained unclear, and few studies have sought to elucidate possible mechanisms. After institutional review board approval, a retrospective review of all pediatric patients with scald burns admitted to the Burn Center between 2010 and 2013 was conducted. Variables collected included age, sex, weight, height, race, ethnicity, socioeconomic status or type of insurance, hospital length of stay, burn size and location, Department of Child and Family Services (DCFS) involvement, time to intubation from admission, reason for intubation, need for MV, duration of MV, need for operative intervention, 24-hour and 48-hour total fluid intake and urine output, glucose levels, infectious complications, comorbidities, and mortality. Patients who required MV were then compared with those who did not require MV to identify statistically significant differences between groups. The MV patients (n = 6) and nonventilated patients (n = 339) did not show significant differences in regards to gender, body mass index, ethnicity, and type of insurance; however, MV patients were younger and had larger burns. The mean age of MV patients was 8.2 + 5.0 months compared with 40.7 + 45.2 months for non-MV (P = .002). The mean percentage of TBSA burn in MV patients was 17.3 + 9.0% compared with 4.5 + 3.9% for non-MV (P < .001). Burn location was significant, and 66.6% of MV patients had burns on the face or neck compared with 23.6% of non-MV (P = .015). MV patients were more likely to have been victims of child abuse, as DCFS was involved in 67% of MV patients vs. 28% of non-MV patients (P = .036). Fifty percent of patients requiring MV had either

  7. Multiple extra-synaptic spillover mechanisms regulate prolonged activity in cerebellar Golgi cell–granule cell loops

    PubMed Central

    Holtzman, Tahl; Sivam, Vanessa; Zhao, Tian; Frey, Oivier; van der Wal, Peter Dow; de Rooij, Nico F; Dalley, Jeffrey W; Edgley, Steve A

    2011-01-01

    Abstract Despite a wealth of in vitro and modelling studies it remains unclear how neuronal populations in the cerebellum interact in vivo. We address the issue of how the cerebellar input layer processes sensory information, with particular focus on the granule cells (input relays) and their counterpart inhibitory interneurones, Golgi cells. Based on the textbook view, granule cells excite Golgi cells via glutamate forming a negative feedback loop. However, Golgi cells express inhibitory mGluR2 receptors suggesting an inhibitory role for glutamate. We set out to test this glutamatergic paradox in Golgi cells. Here we show that granule cells and Golgi cells interact through extra-synaptic signalling mechanisms during sensory information processing, as well as synaptic mechanisms. We demonstrate that such interactions depend on granule cell-derived glutamate acting via inhibitory mGluR2 receptors leading causally to the suppression of Golgi cell activity for several hundreds of milliseconds. We further show that granule cell-derived inhibition of Golgi cell activity is regulated by GABA-dependent extra-synaptic Golgi cell inhibition of granule cells, identifying a regulatory loop in which glutamate and GABA may be critical regulators of Golgi cell–granule cell functional activity. Thus, granule cells may promote their own prolonged activity via paradoxical feed-forward inhibition of Golgi cells, thereby enabling information processing over long timescales. PMID:21669981

  8. Prolonged Oxaliplatin Exposure Alters Intracellular Calcium Signaling: A New Mechanism To Explain Oxaliplatin-Associated Peripheral Neuropathy

    PubMed Central

    Schulze, Christin; McGowan, Margit; Jordt, Sven; Ehrlich, Barbara E

    2012-01-01

    Oxaliplatin is a platinum based cytotoxic agent commonly used to treat colorectal cancers. Despite its effectiveness, oxaliplatin administration is associated with the development of cold-induced peripheral neuropathy. This potentially permanent side effect is provoked by cold exposure and can range from mild and self limited to severe and debilitating. Even with tumor shrinkage, these painful side effects can force dose-reduction or discontinuation of treatment. Neither the mechanism of action of oxaliplatin nor that of cold-induced neuropathy is understood. Paclitaxel, an entirely different chemotherapeutic agent used to treat a variety of malignancies, also is associated with the development of peripheral neuropathy. Unlike oxaliplatin, neurotoxicity arising from paclitaxel treatment is better understood and was found to have profound effects on intracellular calcium signaling (1,2). In this study we examined the effects of oxaliplatin on calcium signaling pathways and found that acute exposure of either a neuroblastoma cell line or primary neurons with therapeutic concentrations of oxaliplatin had no effect on intracellular calcium signaling. We also found that cellular temperature sensors (TRP channels) were also not activated by oxaliplatin. Interestingly, prolonged exposure of oxaliplatin sensitized cells to subsequent stimuli and enhanced the magnitude of intracellular calcium responses. Taken together, our results suggest that acute oxaliplatin exposure will not induce abnormal calcium signaling but oxaliplatin-primed cells do exhibit enhanced sensitivity. These findings provide new insight to the mechanism behind oxaliplatin-induced neuropathy. PMID:21859566

  9. Prospective observational cohort study of patients with weaning failure admitted to a specialist weaning, rehabilitation and home mechanical ventilation centre

    PubMed Central

    Mifsud Bonnici, Denise; Sanctuary, Thomas; Murphy, Patrick B; Steier, Joerg; Marino, Philip; Pattani, Hina; Creagh-Brown, Ben C; Hart, Nicholas

    2016-01-01

    Objectives According to National Health Service England (NHSE) specialist respiratory commissioning specification for complex home ventilation, patients with weaning failure should be referred to a specialist centre. However, there are limited data reporting the clinical outcomes from such centres. Setting Prospective observational cohort study of patients admitted to a UK specialist weaning, rehabilitation and home mechanical ventilation centre between February 2005 and July 2013. Participants 262 patients admitted with a median age of 64.2 years (IQR 52.6–73.2 years). 59.9% were male. Results 39.7% of patients had neuromuscular and/or chest wall disease, 21% were postsurgical, 19.5% had chronic obstructive pulmonary disease (COPD), 5.3% had obesity-related respiratory failure and 14.5% had other diagnoses. 64.1% of patients were successfully weaned, with 38.2% weaned fully from ventilation, 24% weaned to nocturnal non-invasive ventilation (NIV), 1.9% weaned to nocturnal NIV with intermittent NIV during the daytime. 21.4% of patients were discharged on long-term tracheostomy ventilation. The obesity-related respiratory failure group were most likely to wean (relative risk (RR) for weaning success=1.48, 95% CI 1.35 to 1.77; p<0.001), but otherwise weaning success rates did not significantly vary by diagnostic group. The median time-to-wean was 19 days (IQR 9–33) and the median duration of stay was 31 days (IQR 16–50), with no difference observed between the groups. Weaning centre mortality was 14.5%, highest in the COPD group (RR=2.15, 95% CI 1.19 to 3.91, p=0.012) and lowest in the neuromuscular and/or chest wall disease group (RR=0.34, 95% CI 0.16 to 0.75, p=0.007). Of all patients discharged alive, survival was 71.7% at 6 months and 61.8% at 12 months postdischarge. Conclusions Following NHSE guidance, patients with weaning delay and failure should be considered for transfer to a specialist centre where available, which can demonstrate

  10. The Effect of Equal Ratio Ventilation on Oxygenation, Respiratory Mechanics, and Cerebral Perfusion Pressure During Laparoscopy in the Trendelenburg Position.

    PubMed

    Jo, Youn Yi; Kim, Ji Young; Chang, Young Jin; Lee, Sehwan; Kwak, Hyun Jeong

    2016-06-01

    The aim of this study was to investigate the effects of equal ratio ventilation (ERV) on oxygenation, respiratory mechanics, and the cerebral perfusion pressure during pneumoperitoneum in the Trendelenburg position. Thirty patients undergoing laparoscopic low anterior resection (25 to 65 y) were enrolled. Mechanical ventilator was set to volume-controlled mode at an inspiratory to expiratory (I:E) ratio of 1:2 with a tidal volume of 8 mL/kg of ideal body weight with a 5 cm H2O positive end-expiratory pressure. Twenty minutes after pneumoperitoneum in the Trendelenburg position, the I:E ratio was changed to 1:1 for 20 minutes and then restored to 1:2. No significant changes in arterial oxygen tension and respiratory compliance after adopting ERV. Mean arterial pressure and cerebral perfusion pressure decreased significantly over time after adopting the Trendelenburg position during pneumoperitoneum (P=0.014 and 0.005, respectively). In conclusion, there was no improvement in oxygenation or respiratory mechanics with ERV. PMID:27258912

  11. Home Mechanical Ventilation in Childhood-Onset Hereditary Neuromuscular Diseases: 13 Years’ Experience at a Single Center in Korea

    PubMed Central

    Han, Young Joo; Park, June Dong; Lee, Bongjin; Choi, Yu Hyeon; Suh, Dong In; Lim, Byung Chan; Chae, Jong-Hee

    2015-01-01

    Introduction Children with hereditary neuromuscular diseases (NMDs) are at a high risk of morbidity and mortality related to respiratory failure. The use of home mechanical ventilation (HMV) has saved the lives of many children with NMD but, due to a lack of studies, dependable guidelines are not available. We drew upon our experience to compare the various underlying NMDs and to evaluate HMV with regard to respiratory morbidity, the proper indications and timing for its use, and to develop a policy to improve the quality of home noninvasive ventilation (NIV). Methods We retrospectively analyzed the medical records of 57 children with childhood-onset hereditary NMDs in whom HMV was initiated between January 2000 and May 2013 at Seoul National University Children's Hospital. The degree of respiratory morbidity was estimated by the frequency and duration of hospitalizations caused by respiratory distress. Results The most common NMD was spinal muscular atrophy (SMA, n = 33). Emergent mechanical ventilation was initiated in 44% of the patients before the confirmed diagnosis, and the indicators of pre-HMV respiratory morbidity (e.g., extubation trials, hypoxia, hospitalizations, and intensive care unit stay) were greater in these patients than in others. The proportion of post-HMV hospitalizations (range, 0.00−0.52; median, 0.01) was lower than that of pre-HMV hospitalizations (0.02−1.00; 0.99) (P < 0.001). Eight patients were able to maintain home NIV. The main causes of NIV failure were air leakage and a large amount of airway secretions. Conclusions The application of HMV helped reduce respiratory morbidity in children with childhood-onset hereditary NMD. Patients with SMA type I can benefit from an early diagnosis and the timely application of HMV. The choice between invasive and noninvasive HMV should be based on the patient’s age and NIV trial tolerance. Systematic follow-up guidelines provided by a multidisciplinary team are needed. PMID:25822836

  12. Imaging of the three-dimensional alveolar structure and the alveolar mechanics of a ventilated and perfused isolated rabbit lung with Fourier domain optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Popp, Alexander; Wendel, Martina; Knels, Lilla; Koch, T.; Koch, Edmund

    2006-01-01

    In this feasibility study, Fourier domain optical coherence tomography (FDOCT) is used for visualizing the 3-D structure of fixated lung parenchyma and to capture real-time cross sectional images of the subpleural alveolar mechanics in a ventilated and perfused isolated rabbit lung. The compact and modular setup of the FDOCT system allows us to image the first 500 µm of subpleural lung parenchyma with a 3-D resolution of 16×16×8 µm (in air). During mechanical ventilation, real-time cross sectional FDOCT images visualize the inflation and deflation of alveoli and alveolar sacks (acini) in successive images of end-inspiratory and end-expiratory phase. The FDOCT imaging shows the relation of local alveolar mechanics to the setting of tidal volume (VT), peak airway pressure, and positive end-expiratory pressure (PEEP). Application of PEEP leads to persistent recruitment of alveoli and acini in the end-expiratory phase, compared to ventilation without PEEP where alveolar collapse and reinflation are observed. The imaging of alveolar mechanics by FDOCT will help to determine the amount of mechanical stress put on the alveolar walls during tidal ventilation, which is a key factor in understanding the development of ventilator induced lung injury (VILI).

  13. Imaging of the three-dimensional alveolar structure and the alveolar mechanics of a ventilated and perfused isolated rabbit lung with Fourier domain optical coherence tomography.

    PubMed

    Popp, Alexander; Wendel, Martina; Knels, Lilla; Koch, Thea; Koch, Edmund

    2006-01-01

    In this feasibility study, Fourier domain optical coherence tomography (FDOCT) is used for visualizing the 3-D structure of fixated lung parenchyma and to capture real-time cross sectional images of the subpleural alveolar mechanics in a ventilated and perfused isolated rabbit lung. The compact and modular setup of the FDOCT system allows us to image the first 500 microm of subpleural lung parenchyma with a 3-D resolution of 16 x 16 x 8 microm (in air). During mechanical ventilation, real-time cross sectional FDOCT images visualize the inflation and deflation of alveoli and alveolar sacks (acini) in successive images of end-inspiratory and end-expiratory phase. The FDOCT imaging shows the relation of local alveolar mechanics to the setting of tidal volume (VT), peak airway pressure, and positive end-expiratory pressure (PEEP). Application of PEEP leads to persistent recruitment of alveoli and acini in the end-expiratory phase, compared to ventilation without PEEP where alveolar collapse and reinflation are observed. The imaging of alveolar mechanics by FDOCT will help to determine the amount of mechanical stress put on the alveolar walls during tidal ventilation, which is a key factor in understanding the development of ventilator induced lung injury (VILI). PMID:16526892

  14. The effect of manual lung hyperinflation and postural drainage on pulmonary complications in mechanically ventilated trauma patients.

    PubMed

    Ntoumenopoulos, G; Gild, A; Cooper, D J

    1998-10-01

    This study questioned whether manual lung hyperinflation (MHI) and postural drainage reduced the incidence of nosocomial pneumonia or improved other outcome variables in mechanically ventilated trauma patients. Patients were withdrawn from the study if they developed nosocomial pneumonia according to a predetermined definition or on the clinical suspicion of nosocomial pneumonia by the attending intensivist. Of the 46 patients who fulfilled all the inclusion criteria and were enrolled into the study, 22 patients were randomized to group A (physiotherapy) and 24 patients to group B (control group). Twice as many patients were withdrawn in group B (8/24) compared with group A (4/22), although the differences were not statistically significant, [X2(1, 1) = 1.36, P = 0.24]. The length of time receiving mechanical ventilation and in the ICU was similar between the two groups and there were no differences in pulmonary dysfunction ("worst" daily PaO2/FiO2 ratio) between the two groups. There were no ICU deaths in either group. Physiotherapy as used in this study was not associated with a reduced incidence of nosocomial pneumonia based on standard clinical criteria. Nevertheless the trend to more frequent nosocomial pneumonia in the control patients suggests that a larger study in more severely injured patients with stricter clinical criteria for the definition of nosocomial pneumonia is indicated. PMID:9807602

  15. Pulse pressure variation does not reflect stroke volume variation in mechanically ventilated rats with lipopolysaccharide-induced pneumonia.

    PubMed

    Cherpanath, Thomas G V; Smeding, Lonneke; Lagrand, Wim K; Hirsch, Alexander; Schultz, Marcus J; Groeneveld, Johan A B

    2014-01-01

    1. The present study examined the relationship between centrally measured stroke volume variation (SVV) and peripherally derived pulse pressure variation (PPV) in the setting of increased total arterial compliance (CA rt ). 2. Ten male Wistar rats were anaesthetized, paralysed and mechanically ventilated before being randomized to receive intrapulmonary lipopolysaccharide (LPS) or no LPS. Pulse pressure (PP) was derived from the left carotid artery, whereas stroke volume (SV) was measured directly in the left ventricle. Values of SVV and PPV were calculated over three breaths. Balloon inflation of a catheter positioned in the inferior vena cava was used, for a maximum of 30 s, to decrease preload while the SVV and PPV measurements were repeated. Values of CA rt were calculated as SV/PP. 3. Intrapulmonary LPS increased CA rt and SV. Values of SVV and PPV increased in both LPS-treated and untreated rats during balloon inflation. There was a correlation between SVV and PPV in untreated rats before (r = 0.55; P = 0.005) and during (r = 0.69; P < 0.001) occlusion of the vena cava. There was no such correlation in LPS-treated rats either before (r = -0.08; P = 0.70) or during (r = 0.36; P = 0.08) vena cava occlusion. 4. In conclusion, under normovolaemic and hypovolaemic conditions, PPV does not reflect SVV during an increase in CA rt following LPS-induced pneumonia in mechanically ventilated rats. Our data caution against their interchangeability in human sepsis. PMID:24372424

  16. Analyzing small data sets using Bayesian estimation: the case of posttraumatic stress symptoms following mechanical ventilation in burn survivors

    PubMed Central

    van de Schoot, Rens; Broere, Joris J.; Perryck, Koen H.; Zondervan-Zwijnenburg, Mariëlle; van Loey, Nancy E.

    2015-01-01

    Background The analysis of small data sets in longitudinal studies can lead to power issues and often suffers from biased parameter values. These issues can be solved by using Bayesian estimation in conjunction with informative prior distributions. By means of a simulation study and an empirical example concerning posttraumatic stress symptoms (PTSS) following mechanical ventilation in burn survivors, we demonstrate the advantages and potential pitfalls of using Bayesian estimation. Methods First, we show how to specify prior distributions and by means of a sensitivity analysis we demonstrate how to check the exact influence of the prior (mis-) specification. Thereafter, we show by means of a simulation the situations in which the Bayesian approach outperforms the default, maximum likelihood and approach. Finally, we re-analyze empirical data on burn survivors which provided preliminary evidence of an aversive influence of a period of mechanical ventilation on the course of PTSS following burns. Results Not suprisingly, maximum likelihood estimation showed insufficient coverage as well as power with very small samples. Only when Bayesian analysis, in conjunction with informative priors, was used power increased to acceptable levels. As expected, we showed that the smaller the sample size the more the results rely on the prior specification. Conclusion We show that two issues often encountered during analysis of small samples, power and biased parameters, can be solved by including prior information into Bayesian analysis. We argue that the use of informative priors should always be reported together with a sensitivity analysis. PMID:25765534

  17. Exposure of pink salmon embryos to dissolved polynuclear aromatic hydrocarbons delays development, prolonging vulnerability to mechanical damage.

    PubMed

    Carls, Mark G; Thedinga, John F

    2010-06-01

    Exposure to dissolved polynuclear aromatic hydrocarbons (PAHs) from crude oil delays pink salmon (Oncorhynchus gorbuscha) embryo development, thus prolonging their susceptibility to mechanical damage (shock). Exposure also caused mortality, edema, and anemia consistent with previous studies. Hatching and yolk consumption were delayed, indicating the rate of embryonic development was slowed by PAH exposure. The net result was that exposed embryos were more susceptible to shock than normal, unexposed embryos. Susceptibility to shock was protracted by 4-6d for more than a month in embryos exposed to exponentially declining, dissolved PAH concentrations in water passed through oiled rock; the initial total PAH concentration was 22.4microgL(-1) and the geometric mean concentration was 4.5microgL(-1) over the first 20d. Protracted susceptibility to shock caused by exposure to PAHs dissolved from oil could potentially increase the reported incidence of mortality in oiled stream systems, such as those in Prince William Sound after the Exxon Valdez oil spill, if observers fail to discriminate between direct mortality and shock-induced mortality. PMID:20089299

  18. A Simple “Blood-Saving Bundle” Reduces Diagnostic Blood Loss and the Transfusion Rate in Mechanically Ventilated Patients

    PubMed Central

    Riessen, Reimer; Behmenburg, Melanie; Blumenstock, Gunnar; Guenon, Doris; Enkel, Sigrid; Schäfer, Richard; Haap, Michael

    2015-01-01

    Introduction Aim of this study was to reduce blood loss caused by diagnostic blood sampling and to minimize the development of anemia in a high-risk group of mechanically ventilated medical intensive care patients. We therefore implemented a “blood-saving bundle” (BSB) combining a closed-loop arterial blood sampling system, smaller sampling tubes, reduced frequency of blood drawings, and reduced sample numbers. Methods The study included all patients from our medical ICU who were ventilated for more than 72 hours. Exclusion criteria were: acute or chronic anemia on admission, bleeding episode(s) during the ICU stay, or end-of-life therapy. The BSB was introduced in 2009 with training and educational support. Patients treated in 2008, before the introduction of the BSB, served as a control group (n = 41, 617 observation days), and were compared with patients treated in 2010 after the introduction of the BSB (BSB group, n = 50, 559 observation days). Primary endpoints were blood loss per day, and development of anemia. Secondary endpoints were numbers of blood transfusions, number of days on mechanical ventilation, and length of the ICU stay. Results Mean blood loss per ICU day was decreased from 43.3 ml (95% CI: 41.2 to 45.3 ml) in the controls to 15.0 ml (14.3 to 15.7 ml) in the BSB group (P < 0.001). The introduction of a closed-loop arterial blood sampling system was the major contributor to this effect. Mean hemoglobin concentrations showed no significant differences in both groups during the ICU stay. Hemoglobin values <9 g/dl, however, were recorded in 21.2% of observation days in the controls versus 15.4% in the BSB group (P = 0.01). Units of transfused red blood cells per 100 observation days decreased from 7 to 2.3 (P < 0.001). The mean number of ventilation days was 7.1 days (6.1 to 8.3 days) in the controls and 7.5 days (6.6 to 8.5 days) in the BSB group (P = NS). In total, patients in the BSB group stayed in ICU for a mean of 9.9 days (8.6 to 11

  19. Comparing the effect of open and closed endotracheal suctioning on pain and oxygenation in post CABG patients under mechanical ventilation

    PubMed Central

    Mohammadpour, Ali; Amini, Shahram; Shakeri, Mohammad Taghi; Mirzaei, Sahereh

    2015-01-01

    Background: The aim of this study was to compare changes in pain, oxygenation, and ventilation following endotracheal suctioning with open and closed suctioning systems in post coronary artery bypass grafting (CABG) patients. Materials and Methods: 130 post CABG mechanically ventilated patients were randomly allocated to undergo either open (n = 75) or closed (n = 55) endotracheal suctioning for 15 s. The patients received 100% oxygen for 1 min before and after suctioning. Pain score using critical-care pain objective tool (CPOT) was compared during suctioning between the two groups. Arterial oxygen pressure (PaO2), PaO2 to fraction of inspired oxygen (FiO2) (PF) ratio, and arterial carbon dioxide pressure (PaCO2) were compared at baseline and 5 min after suctioning. Peripheral oxygen saturation (SpO2) was compared at baseline, during suctioning, and at 1 min interval after suctioning for 5 min between the two groups. Results: The patients were the same with regard to CPOT scores, i.e. 3.21 (1.89) and 2.94 (1.56) in the open and closed suctioning systems, respectively. SpO2 did not change significantly between the two groups. Changes in PaO2 and PF ratio was more significant in the open than in the closed system (P = 0.007). Patients in the open group had a higher PaCO2 than those in the closed group, i.e. 40.54 (6.56) versus 38.02 (6.10), and the P value was 0.027. Conclusions: Our study revealed that patients’ pain and SpO2 changes are similar following endotracheal suctioning in both suctioning systems. However, oxygenation and ventilation are better preserved with closed suctioning system. PMID:25878695

  20. Kangaroo (skin-to-skin) care with a preterm infant before, during, and after mechanical ventilation.

    PubMed

    Swinth, Joan Y; Anderson, Gene Cranston; Hadeed, Anthony J

    2003-01-01

    Using kangaroo care (KC) with unstable and/or ventilated infants remains controversial. In this article, potential advantages for ventilated infants and their mothers are discussed. The 33-week-gestation infant in this case study presented with mild respiratory distress at birth, requiring supplemental oxygen at hour 2. With no improvement by hour 18, KC was also begun, first for 1.25 hours and then, 2 hours later, for 3.5 hours. The infant was intubated at hour 45 for increasing respiratory distress, and KC resumed 24 hours later for 1 hour and 3 hours after that for an additional 3 hours. Extubation occurred at hour 90. Kangaroo care resumed 2 hours later for periods of 1.5, 1.5, and 1 hour over the next 8 hours, 2.5 hours more later that day (day 5, the last day of data collection). Thereafter, KC was done intermittently until discharge on day 9. Total KC times for pre-vent, vent, and immediate post-vent periods were 4.75, 4, and 6.5 hours, respectively. The data from this study suggest that KC may assist in, rather than retard, recovery from respiratory distress. KC may also foster maternal relaxation and minimize maternal stress. PMID:14700180

  1. Achievement of Prolonged Oxygen Detection in Room-Temperature Ionic Liquids on Mechanically Polished Platinum Screen-Printed Electrodes.

    PubMed

    Lee, Junqiao; Arrigan, Damien W M; Silvester, Debbie S

    2016-05-17

    The demonstration of prolonged amperometric detection of oxygen in room-temperature ionic liquids (RTILs) was achieved by the use of mechanical polishing to activate platinum screen-printed electrodes (Pt-SPEs). The RTILs studied were 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][NTf2]) and N-butyl-N-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide ([C4mpyrr][NTf2]). It was found that voltammetry on polished Pt-SPEs exhibited less deterioration (in terms of voltammogram shapes, stability of peak currents, and appearance of contaminant peaks) from long-term consecutive cycling under 100% vol oxygen flow in both RTILs. The detection capability of these RTIL/Pt-SPE systems, initially subjected to long-term consecutive voltammetric cycling, was also investigated by cyclic voltammetry (CV) and long-term chronoamperometry (LTCA). Current versus concentration plots were linear on both unpolished and polished electrodes for 10-100% vol O2 (using CV) and 0.1-5% vol O2 (using LTCA). However, sensitivities and limits of detection (LODs) from CV were found to improve significantly on polished electrodes compared to unpolished electrodes, particularly in [C2mim][NTf2], but also moderately in [C4mpyrr][NTf2]. The lowest LODs (of ca. 0.1% vol O2) were found on polished SPEs using LTCA, with the most stable responses observed in [C4mpyrr][NTf2]. Calibration graphs could not be obtained on unpolished electrodes in both RTILs using LTCA. The results show that polishing markedly improves the analytical performances of Pt-SPEs for oxygen sensing in RTILs. The reusability of such disposable Pt-SPEs, after the surfaces had been experimentally fouled, was also demonstrated through the use of polishing. Mechanical polishing of Pt-SPE devices offers a viable approach to performance improvement for amperometric gas sensing. PMID:27063949

  2. Development of a time-cycled volume-controlled pressure-limited respirator and lung mechanics system for total liquid ventilation.

    PubMed

    Larrabe, J L; Alvarez, F J; Cuesta, E G; Valls-i-Soler, A; Alfonso, L F; Arnaiz, A; Fernández, M B; Loureiro, B; Publicover, N G; Roman, L; Casla, J A; Gómez, M A

    2001-10-01

    Total liquid ventilation can support gas exchange in animal models of lung injury. Clinical application awaits further technical improvements and performance verification. Our aim was to develop a liquid ventilator, able to deliver accurate tidal volumes, and a computerized system for measuring lung mechanics. The computer-assisted, piston-driven respirator controlled ventilatory parameters that were displayed and modified on a real-time basis. Pressure and temperature transducers along with a lineal displacement controller provided the necessary signals to calculate lung mechanics. Ten newborn lambs (<6 days old) with respiratory failure induced by lung lavage, were monitored using the system. Electromechanical, hydraulic, and data acquisition/analysis components of the ventilator were developed and tested in animals with respiratory failure. All pulmonary signals were collected synchronized in time, displayed in real-time, and archived on digital media. The total mean error (due to transducers, analog-to-digital conversion, amplifiers, etc.) was less than 5% compared with calibrated signals. Components (tubing, pistons, etc.) in contact with exchange fluids were developed so that they could be readily switched, a feature that will be important in clinical settings. Improvements in gas exchange and lung mechanics were observed during liquid ventilation, without impairment of cardiovascular profiles. The total liquid ventilator maintained accurate control of tidal volumes and the sequencing of inspiration/expiration. The computerized system demonstrated its ability to monitor in vivo lung mechanics, providing valuable data for early decision making. PMID:11585037

  3. Sildenafil to facilitate weaning from inhaled nitric oxide and mechanical ventilation in a patient with severe secondary pulmonary hypertension and a patent foramen ovale.

    PubMed

    Elias, Shlomo; Sviri, Sigal; Orenbuch-Harroch, Efrat; Fellig, Yakov; Ben-Yehuda, Arie; Fridlender, Zvi G; Gilon, Dan; Bayya, Abed

    2011-10-01

    We describe the case of a woman who presented to the intensive care unit with acute respiratory failure that required mechanical ventilation. She had severe pulmonary hypertension secondary to interstitial lung disease, and her history included sarcoidosis and tuberculosis. She was dependent on inhaled nitric oxide (INO) to maintain safe arterial oxygen saturation and could not be weaned from mechanical ventilation. Echocardiography revealed a patent foramen ovale with substantial right-to-left shunt, which probably contributed to her hypoxemia. Sildenafil enabled weaning from INO and substantially reduced the flow through the patent foramen ovale. She was successfully extubated and discharged home. To our knowledge, this is the first report of weaning from INO and mechanical ventilation in a patient with both severe secondary pulmonary hypertension and a right-to-left shunt through a patent foramen ovale. PMID:21513610

  4. Blunt Chest Trauma in Mice after Cigarette Smoke-Exposure: Effects of Mechanical Ventilation with 100% O2.

    PubMed

    Wagner, Katja; Gröger, Michael; McCook, Oscar; Scheuerle, Angelika; Asfar, Pierre; Stahl, Bettina; Huber-Lang, Markus; Ignatius, Anita; Jung, Birgit; Duechs, Matthias; Möller, Peter; Georgieff, Michael; Calzia, Enrico; Radermacher, Peter; Wagner, Florian

    2015-01-01

    Cigarette smoking (CS) aggravates post-traumatic acute lung injury and increases ventilator-induced lung injury due to more severe tissue inflammation and apoptosis. Hyper-inflammation after chest trauma is due to the physical damage, the drop in alveolar PO2, and the consecutive hypoxemia and tissue hypoxia. Therefore, we tested the hypotheses that 1) CS exposure prior to blunt chest trauma causes more severe post-traumatic inflammation and thereby aggravates lung injury, and that 2) hyperoxia may attenuate this effect. Immediately after blast wave-induced blunt chest trauma, mice (n=32) with or without 3-4 weeks of CS exposure underwent 4 hours of pressure-controlled, thoraco-pulmonary compliance-titrated, lung-protective mechanical ventilation with air or 100% O2. Hemodynamics, lung mechanics, gas exchange, and acid-base status were measured together with blood and tissue cytokine and chemokine concentrations, heme oxygenase-1 (HO-1), activated caspase-3, and hypoxia-inducible factor 1-α (HIF-1α) expression, nuclear factor-κB (NF-κB) activation, nitrotyrosine formation, purinergic receptor 2X4 (P2XR4) and 2X7 (P2XR7) expression, and histological scoring. CS exposure prior to chest trauma lead to higher pulmonary compliance and lower PaO2 and Horovitz-index, associated with increased tissue IL-18 and blood MCP-1 concentrations, a 2-4-fold higher inflammatory cell infiltration, and more pronounced alveolar membrane thickening. This effect coincided with increased activated caspase-3, nitrotyrosine, P2XR4, and P2XR7 expression, NF-κB activation, and reduced HIF-1α expression. Hyperoxia did not further affect lung mechanics, gas exchange, pulmonary and systemic cytokine and chemokine concentrations, or histological scoring, except for some patchy alveolar edema in CS exposed mice. However, hyperoxia attenuated tissue HIF-1α, nitrotyrosine, P2XR7, and P2XR4 expression, while it increased HO-1 formation in CS exposed mice. Overall, CS exposure aggravated post

  5. Blunt Chest Trauma in Mice after Cigarette Smoke-Exposure: Effects of Mechanical Ventilation with 100 % O2

    PubMed Central

    Wagner, Katja; Gröger, Michael; McCook, Oscar; Scheuerle, Angelika; Asfar, Pierre; Stahl, Bettina; Huber-Lang, Markus; Ignatius, Anita; Jung, Birgit; Duechs, Matthias; Möller, Peter; Georgieff, Michael; Calzia, Enrico; Radermacher, Peter; Wagner, Florian

    2015-01-01

    Cigarette smoking (CS) aggravates post-traumatic acute lung injury and increases ventilator-induced lung injury due to more severe tissue inflammation and apoptosis. Hyper-inflammation after chest trauma is due to the physical damage, the drop in alveolar PO2, and the consecutive hypoxemia and tissue hypoxia. Therefore, we tested the hypotheses that 1) CS exposure prior to blunt chest trauma causes more severe post-traumatic inflammation and thereby aggravates lung injury, and that 2) hyperoxia may attenuate this effect. Immediately after blast wave-induced blunt chest trauma, mice (n=32) with or without 3-4 weeks of CS exposure underwent 4 hours of pressure-controlled, thoraco-pulmonary compliance-titrated, lung-protective mechanical ventilation with air or 100 % O2. Hemodynamics, lung mechanics, gas exchange, and acid-base status were measured together with blood and tissue cytokine and chemokine concentrations, heme oxygenase-1 (HO-1), activated caspase-3, and hypoxia-inducible factor 1-α (HIF-1α) expression, nuclear factor-κB (NF-κB) activation, nitrotyrosine formation, purinergic receptor 2X4 (P2XR4) and 2X7 (P2XR7) expression, and histological scoring. CS exposure prior to chest trauma lead to higher pulmonary compliance and lower PaO2 and Horovitz-index, associated with increased tissue IL-18 and blood MCP-1 concentrations, a 2-4-fold higher inflammatory cell infiltration, and more pronounced alveolar membrane thickening. This effect coincided with increased activated caspase-3, nitrotyrosine, P2XR4, and P2XR7 expression, NF-κB activation, and reduced HIF-1α expression. Hyperoxia did not further affect lung mechanics, gas exchange, pulmonary and systemic cytokine and chemokine concentrations, or histological scoring, except for some patchy alveolar edema in CS exposed mice. However, hyperoxia attenuated tissue HIF-1α, nitrotyrosine, P2XR7, and P2XR4 expression, while it increased HO-1 formation in CS exposed mice. Overall, CS exposure aggravated post

  6. Visualization of neonatal lung injury associated with mechanical ventilation using x-ray dark-field radiography

    NASA Astrophysics Data System (ADS)

    Yaroshenko, Andre; Pritzke, Tina; Koschlig, Markus; Kamgari, Nona; Willer, Konstantin; Gromann, Lukas; Auweter, Sigrid; Hellbach, Katharina; Reiser, Maximilian; Eickelberg, Oliver; Pfeiffer, Franz; Hilgendorff, Anne

    2016-04-01

    Mechanical ventilation (MV) and supplementation of oxygen-enriched gas, often needed in postnatal resuscitation procedures, are known to be main risk factors for impaired pulmonary development in the preterm and term neonates. Unfortunately, current imaging modalities lack in sensitivity for the detection of early stage lung injury. The present study reports a new imaging approach for diagnosis and staging of early lung injury induced by MV and hyperoxia in neonatal mice. The imaging method is based on the Talbot-Lau x-ray grating interferometry that makes it possible to quantify the x-ray small-angle scattering on the air-tissue interfaces. This so-called dark-field signal revealed increasing loss of x-ray small-angle scattering when comparing images of neonatal mice undergoing hyperoxia and MV-O2 with animals kept at room air. The changes in the dark field correlated well with histologic findings and provided superior differentiation than conventional x-ray imaging and lung function testing. The results suggest that x-ray dark-field radiography is a sensitive tool for assessing structural changes in the developing lung. In the future, with further technical developments x-ray dark-field imaging could be an important tool for earlier diagnosis and sensitive monitoring of lung injury in neonates requiring postnatal oxygen or ventilator therapy.

  7. Visualization of neonatal lung injury associated with mechanical ventilation using x-ray dark-field radiography

    PubMed Central

    Yaroshenko, Andre; Pritzke, Tina; Koschlig, Markus; Kamgari, Nona; Willer, Konstantin; Gromann, Lukas; Auweter, Sigrid; Hellbach, Katharina; Reiser, Maximilian; Eickelberg, Oliver; Pfeiffer, Franz; Hilgendorff, Anne

    2016-01-01

    Mechanical ventilation (MV) and supplementation of oxygen-enriched gas, often needed in postnatal resuscitation procedures, are known to be main risk factors for impaired pulmonary development in the preterm and term neonates. Unfortunately, current imaging modalities lack in sensitivity for the detection of early stage lung injury. The present study reports a new imaging approach for diagnosis and staging of early lung injury induced by MV and hyperoxia in neonatal mice. The imaging method is based on the Talbot-Lau x-ray grating interferometry that makes it possible to quantify the x-ray small-angle scattering on the air-tissue interfaces. This so-called dark-field signal revealed increasing loss of x-ray small-angle scattering when comparing images of neonatal mice undergoing hyperoxia and MV-O2 with animals kept at room air. The changes in the dark field correlated well with histologic findings and provided superior differentiation than conventional x-ray imaging and lung function testing. The results suggest that x-ray dark-field radiography is a sensitive tool for assessing structural changes in the developing lung. In the future, with further technical developments x-ray dark-field imaging could be an important tool for earlier diagnosis and sensitive monitoring of lung injury in neonates requiring postnatal oxygen or ventilator therapy. PMID:27072871

  8. Severity of disease estimation and risk-adjustment for comparison of outcomes in mechanically ventilated patients using electronic routine care data.

    PubMed

    van Mourik, Maaike S M; Moons, Karel G M; Murphy, Michael V; Bonten, Marc J M; Klompas, Michael

    2015-07-01

    BACKGROUND Valid comparison between hospitals for benchmarking or pay-for-performance incentives requires accurate correction for underlying disease severity (case-mix). However, existing models are either very simplistic or require extensive manual data collection. OBJECTIVE To develop a disease severity prediction model based solely on data routinely available in electronic health records for risk-adjustment in mechanically ventilated patients. DESIGN Retrospective cohort study. PARTICIPANTS Mechanically ventilated patients from a single tertiary medical center (2006-2012). METHODS Predictors were extracted from electronic data repositories (demographic characteristics, laboratory tests, medications, microbiology results, procedure codes, and comorbidities) and assessed for feasibility and generalizability of data collection. Models for in-hospital mortality of increasing complexity were built using logistic regression. Estimated disease severity from these models was linked to rates of ventilator-associated events. RESULTS A total of 20,028 patients were initiated on mechanical ventilation, of whom 3,027 deceased in hospital. For models of incremental complexity, area under the receiver operating characteristic curve ranged from 0.83 to 0.88. A simple model including demographic characteristics, type of intensive care unit, time to intubation, blood culture sampling, 8 common laboratory tests, and surgical status achieved an area under the receiver operating characteristic curve of 0.87 (95% CI, 0.86-0.88) with adequate calibration. The estimated disease severity was associated with occurrence of ventilator-associated events. CONCLUSIONS Accurate estimation of disease severity in ventilated patients using electronic, routine care data was feasible using simple models. These estimates may be useful for risk-adjustment in ventilated patients. Additional research is necessary to validate and refine these models. PMID:25881675

  9. Lights and shadows of non-invasive mechanical ventilation for chronic obstructive pulmonary disease (COPD) exacerbations

    PubMed Central

    Lopez-Campos, Jose Luis; Jara-Palomares, Luis; Muñoz, Xavier; Bustamante, Víctor; Barreiro, Esther

    2015-01-01

    Despite the overwhelming evidence justifying the use of non-invasive ventilation (NIV) for providing ventilatory support in chronic obstructive pulmonary disease (COPD) exacerbations, recent studies demonstrated that its application in real-life settings remains suboptimal. European clinical audits have shown that 1) NIV is not invariably available, 2) its availability depends on countries and hospital sizes, and 3) numerous centers declare their inability to provide NIV to all of the eligible patients presenting throughout the year. Even with an established indication, the use of NIV in acute respiratory failure due to COPD exacerbations faces important challenges. First, the location and personnel using NIV should be carefully selected. Second, the use of NIV is not straightforward despite the availability of technologically advanced ventilators. Third, NIV therapy of critically ill patients requires a thorough knowledge of both respiratory physiology and existing ventilatory devices. Accordingly, an optimal team-training experience, the careful selection of patients, and special attention to the selection of devices are critical for optimizing NIV outcomes. Additionally, when applied, NIV should be closely monitored, and endotracheal intubation should be promptly available in the case of failure. Another topic that merits careful consideration is the use of NIV in the elderly. This patient population is particularly fragile, with several physiological and social characteristics requiring specific attention in relation to NIV. Several other novel indications should also be critically examined, including the use of NIV during fiberoptic bronchoscopy or transesophageal echocardiography, as well as in interventional cardiology and pulmonology. The present narrative review aims to provide updated information on the use of NIV in acute settings to improve the clinical outcomes of patients hospitalized for COPD exacerbations. PMID:25829958

  10. High-frequency ventilation.

    PubMed

    Crawford, M R

    1986-08-01

    Over the last six years high-frequency ventilation has been extensively evaluated both in the clinical and laboratory settings. It is now no longer the great mystery it once was, and it is now no longer believed (as many had hoped), that it will solve all the problems associated with mechanical pulmonary ventilation. Although the technique is safe and appears to cause no harm even in the long term, it has not yet been shown to offer any major advantages over conventional mechanical ventilation. PMID:3530042

  11. Effect of Tracheostomy on Weaning Parameters in Difficult-to-Wean Mechanically Ventilated Patients: A Prospective Observational Study

    PubMed Central

    Lim, Chor-Kuan; Ruan, Sheng-Yuan; Lin, Feng-Ching; Wu, Chao-Ling; Chang, Hou-Tai; Jerng, Jih-Shuin; Wu, Huey-Dong; Yu, Chong-Jen

    2015-01-01

    Background and Objective Weaning parameters are commonly measured through an endotracheal tube in mechanically ventilated patients recovering from acute respiratory failure, however this practice has rarely been evaluated in tracheostomized patients. This study aimed to investigate changes in weaning parameters measured before and after tracheostomy, and to explore whether the data measured after tracheostomy were associated with weaning outcomes in difficult-to-wean patients. Methods In a two-year study period, we enrolled orotracheally intubated patients who were prepared for tracheostomy due to difficult weaning. Weaning parameters were measured before and after the conversion to tracheostomy and compared, and the post-tracheostomy data were tested for associations with weaning outcomes. Results A total of 86 patients were included. After tracheostomy, maximum inspiratory pressure (mean difference (Δ) = 4.4, 95% CI, 2.7 to 6.1, P<0.001), maximum expiratory pressure (Δ = 5.4, 95% CI, 2.9 to 8.0, P<0.001) and tidal volume (Δ = 33.7, 95% CI, 9.0 to 58.5, P<0.008) significantly increased, and rapid shallow breathing index (Δ = -14.6, 95% CI, -25.4 to -3.7, P<0.009) and airway resistance (Δ = -4.9, 95% CI, -5.8 to -4.0, P<0.001) significantly decreased. The patients who were successfully weaned within 90 days of the initiation of mechanical ventilation had greater increments in maximum inspiratory pressure (5.9 vs. 2.4, P = 0.04) and maximum expiratory pressure (8.0 vs. 2.0, P = 0.02) after tracheostomy than those who were unsuccessfully weaned. Conclusions In conclusion, the conversion from endotracheal tube to tracheostomy significantly improved the measured values of weaning parameters in difficult-to-wean patients who subsequently weaned successfully from the mechanical ventilator. The change was significant only for airway resistance in patients who failed weaning. Trial Registration ClinicalTrials.gov NCT01312142 PMID:26379127

  12. [Ventilation strategies in the child with severe hypoxemic respiratory failure].

    PubMed

    Donoso F, Alejandro; Arriagada S, Daniela; Díaz R, Franco; Cruces R, Pablo

    2015-01-01

    In this review, we assemble the fundamental concepts of the use of mechanical ventilation (MV) in children with acute respiratory failure (ARDS) and refractory hypoxemia. We also discusses topics of protective ventilation and recruitment potential, and specifically examine the options of ventilation and/or maneuvers designed to optimize the non-aerated lung tissue: alveolar recruitment maneuvers, positive end-expiratory pressure (PEEP) titulation, high frequency oscillatory ventilation (HFOV), airway pressure release ventilation (APRV), aimed at correcting the mismatch ventilation/perfusion (V/Q): use of prone position. The only pharmacological intervention analyzed is the use of neuromuscular blockers. In clinical practice, the protective MV concept involves using an individual adjustment of the PEEP and volume tidal (V(T)). Use of recruitment maneuvers and PEEP downward titration can improve lung function in patients with ARDS and severe hypoxemia. We must keep in mind HFOV instauration as early as possible in response to failure of MV. The use of early and prolonged prone can improve gas exchange in hopes of a better control of what caused the use of MV. PMID:25739487

  13. Evaluation of the multiple linear regression method to monitor respiratory mechanics in ventilated neonates and young children.

    PubMed

    Rousselot, J M; Peslin, R; Duvivier, C

    1992-07-01

    A potentially useful method to monitor respiratory mechanics in artificially ventilated patients consists of analyzing the relationship between tracheal pressure (P), lung volume (V), and gas flow (V) by multiple linear regression (MLR) using a suitable model. Contrary to other methods, it does not require any particular flow waveform and, therefore, may be used with any ventilator. This approach was evaluated in three neonates and seven young children admitted into an intensive care unit for respiratory disorders of various etiologies. P and V were measured and digitized at a sampling rate of 40 Hz for periods of 20-48 s. After correction of P for the non-linear resistance of the endotracheal tube, the data were first analyzed with the usual linear monoalveolar model: P = PO + E.V + R.V where E and R are total respiratory elastance and resistance, and PO is the static recoil pressure at end-expiration. A good fit of the model to the data was seen in five of ten children. PO, E, and R were reproducible within cycles, and consistent with the patient's age and condition; the data obtained with two ventilatory modes were highly correlated. In the five instances in which the simple model did not fit the data well, they were reanalyzed with more sophisticated models allowing for mechanical non-homogeneity or for non-linearity of R or E. While several models substantially improved the fit, physiologically meaningful results were only obtained when R was allowed to change with lung volume. We conclude that the MLR method is adequate to monitor respiratory mechanics, even when the usual model is inadequate. PMID:1437330

  14. Pressure Controlled Ventilation to Induce Acute Lung Injury in Mice

    PubMed Central

    Koeppen, Michael; Eckle, Tobias; Eltzschig, Holger K.

    2011-01-01

    Murine models are extensively used to investigate acute injuries of different organs systems (1-34). Acute lung injury (ALI), which occurs with prolonged mechanical ventilation, contributes to morbidity and mortality of critical illness, and studies on novel genetic or pharmacological targets are areas of intense investigation (1-3, 5, 8, 26, 30, 33-36). ALI is defined by the acute onset of the disease, which leads to non-cardiac pulmonary edema and subsequent impairment of pulmonary gas exchange (36). We have developed a murine model of ALI by using a pressure-controlled ventilation to induce ventilator-induced lung injury (2). For this purpose, C57BL/6 mice are anesthetized and a tracheotomy is performed followed by induction of ALI via mechanical ventilation. Mice are ventilated in a pressure-controlled setting with an inspiratory peak pressure of 45 mbar over 1 - 3 hours. As outcome parameters, pulmonary edema (wet-to-dry ratio), bronchoalveolar fluid albumin content, bronchoalveolar fluid and pulmonary tissue myeloperoxidase content and pulmonary gas exchange are assessed (2). Using this technique we could show that it sufficiently induces acute lung inflammation and can distinguish between different treatment groups or genotypes (1-3, 5). Therefore this technique may be helpful for researchers who pursue molecular mechanisms involved in ALI using a genetic approach in mice with gene-targeted deletion. PMID:21587159

  15. Fluid mechanical dispersion of airborne pollutants inside urban street canyons subjecting to multi-component ventilation and unstable thermal stratifications.

    PubMed

    Mei, Shuo-Jun; Liu, Cheng-Wei; Liu, Di; Zhao, Fu-Yun; Wang, Han-Qing; Li, Xiao-Hong

    2016-09-15

    The pedestrian level pollutant transport in street canyons with multiple aspect ratios (H/W) is numerically investigated in the present work, regarding of various unstable thermal stratification scenarios and plain surrounding. Non-isothermal turbulent wind flow, temperature field and pollutant spread within and above the street canyons are solved by the realizable k-ε turbulence model along with the enhanced wall treatment. One-vortex flow regime is observed for shallow canyons with H/W=0.5, whereas multi-vortex flow regime is observed for deep canyons with H/W=2.0. Both one-vortex and multi-vortex regimes could be observed for the street canyons with H/W=1.0, where the secondary vortex could be initiated by the flow separation and intensified by unstable thermal stratification. Air exchange rate (AER) and pollutant retention time are adopted to respectively evaluate the street canyon ventilation and pollutant removal performance. A second-order polynomial functional relationship is established between AER and Richardson number (Ri). Similar functional relationship could be established between retention time and Ri, and it is only valid for canyons with one-vortex flow regime. In addition, retention time could be prolonged abruptly for canyons with multi-vortex flow regime. Very weak secondary vortex is presented at the ground level of deep canyons with mild stratification, where pollutants are highly accumulated. However, with the decrease of Ri, pollutant concentration adjacent to the ground reduces accordingly. Present research could be applied to guide the urban design and city planning for enhancing pedestrian environment. PMID:27262984

  16. Nurse and Patient Interaction Behaviors Effects on Nursing Care Quality for Mechanically Ventilated, Older Adults in the ICU

    PubMed Central

    Nilsen, Marci; Sereika, Susan M.; Hoffman, Leslie A.; Barnato, Amber; Donovan, Heidi; Happ, Mary Beth

    2014-01-01

    The study purposes were to 1) describe interaction behaviors and factors that may impact communication and 2) explore associations between interaction behaviors and nursing care quality indicators between 38 mechanically ventilated patients (≥60 years) and their intensive care unit nurses (n=24). Behaviors were measured by rating videotaped observations from the Study of Patient-Nurse Effectiveness with Communication Strategies (SPEACS). Characteristics and quality indicators were obtained from the SPEACS dataset and medical chart abstraction. All positive behaviors occurred at least once. Significant (p<.05) associations were observed between: 1) positive nurse and positive patient behaviors, 2) patient unaided augmentative and alternative communication (AAC) strategies and positive nurse behaviors, 3) individual patient unaided AAC strategies and individual nurse positive behaviors and 4) positive nurse behaviors and pain management, and 5) positive patient behaviors and sedation level. Findings provide evidence that nurse and patient behaviors impact communication and may be associated with nursing care quality. PMID:24496114

  17. 46 CFR 168.15-50 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Accommodations § 168.15-50 Ventilation. (a) All quarters must be adequately ventilated in a manner suitable to the purpose of the space and route of the vessel. (b) When mechanical ventilation is provided for... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation. 168.15-50 Section 168.15-50 Shipping...

  18. Psychometric properties of a novel knowledge assessment tool of mechanical ventilation for emergency medicine residents in the northeastern United States

    PubMed Central

    2016-01-01

    Purpose: Prior descriptions of the psychometric properties of validated knowledge assessment tools designed to determine Emergency medicine (EM) residents understanding of physiologic and clinical concepts related to mechanical ventilation are lacking. In this setting, we have performed this study to describe the psychometric and performance properties of a novel knowledge assessment tool that measures EM residents’ knowledge of topics in mechanical ventilation. Methods: Results from a multicenter, prospective, survey study involving 219 EM residents from 8 academic hospitals in northeastern United States were analyzed to quantify reliability, item difficulty, and item discrimination of each of the 9 questions included in the knowledge assessment tool for 3 weeks, beginning in January 2013. Results: The response rate for residents completing the knowledge assessment tool was 68.6% (214 out of 312 EM residents). Reliability was assessed by both Cronbach’s alpha coefficient (0.6293) and the Spearman-Brown coefficient (0.6437). Item difficulty ranged from 0.39 to 0.96, with a mean item difficulty of 0.75 for all 9 questions. Uncorrected item discrimination values ranged from 0.111 to 0.556. Corrected item-total correlations were determined by removing the question being assessed from analysis, resulting in a range of item discrimination from 0.139 to 0.498. Conclusion: Reliability, item difficulty and item discrimination were within satisfactory ranges in this study, demonstrating acceptable psychometric properties of this knowledge assessment tool. This assessment indicates that this knowledge assessment tool is sufficiently rigorous for use in future research studies or for assessment of EM residents for evaluative purposes. PMID:26924540

  19. Accuracy of pleth variability index to predict fluid responsiveness in mechanically ventilated patients: a systematic review and meta-analysis.

    PubMed

    Chu, Haitao; Wang, Yong; Sun, Yanfei; Wang, Gang

    2016-06-01

    To systemically evaluate the accuracy of pleth variability index to predict fluid responsiveness in mechan