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Clinicians are becoming more aware of the risks of sleep deprivation and unrecognized sleep-disordered breathing in hospitalized patients, most importantly in those patients planning to undergo surgical procedures. Polysomnography is difficult to perform in the hospital setting, such that actigraphy or urinary metabolites of melatonin are often used as surrogate measures, and show that sleep is markedly impaired. Patients in the medical intensive care unit with sepsis or requiring mechanical ventilation may show complete absence of the normal circadian rhythm pattern, and many centers have initiated sleep-enhancement protocols. In postoperative patients, rapid-eye-movement sleep is nearly obliterated, especially in the first 1-2 days after surgery, and this appears closely related to the use of high-dose opioids. Sleep-disordered breathing is common in postoperative patients, and tools such as the Sleep Apnea Clinical Score or the STOP-BANG (Snoring, Tiredness, Observed apnea, and high blood Pressure - Body mass index, Age, Neck circumference, and Gender) questionnaires have been utilized to predict the possibility of obstructive sleep apnea (OSA) and postoperative respiratory complications. Protocols to evaluate patients that determine the need and process for positive-airway-pressure treatment in the hospital patient with OSA are being developed. An obstructive apnea systematic intervention strategy protocol to deal with patients with suspected OSA can help guide diagnostic and therapeutic decision making. Hospitals that are proactive in the development of protocols for identification and management of patients with sleep-disordered breathing are likely to be rewarded with reduced complications and costs, and the issue is sure to be incorporated in future pay-for-performance evaluations. [ABSTRACT FROM AUTHOR]

The acute respiratory distress syndrome (ARDS) is characterized by intense inflammation and alveolar-capillary disruption that can progress to a state of unresolving inflammation and disordered fibrosis, referred to as fibroproliferative, late-stage, or persistent ARDS. These pathophysiologic features may be responsive to corticosteroids, but early high-dose, short-duration therapy was proven ineffective. More recently, several small and one moderate-size multicenter randomized controlled trial (RCT) investigated low-to-moderate-dose prolonged corticosteroid treatment. The RCT and meta-analysis consistently demonstrated improved oxygenation and shorter duration of mechanical ventilation with methylprednisolone. The largest RCT also revealed less pneumonia and shock, and shorter intensive care unit (ICU) stay, but more cases of severe myoneuropathy, with methylprednisolone. There were virtually identical 60-day and 180-day mortality rates for methylprednisolone and placebo in the largest RCT. Sub-group analysis of that study showed significantly higher mortality with methylprednisolone than with placebo when enrollment occurred > 13 days after onset of ARDS, but small sample size and differences in subject characteristics probably confound those results. Most meta-analyses demonstrated trends toward better survival with methylprednisolone, and, when restricted to patients enrolled in RCTs who received prolonged administration of methylprednisolone that was initiated within the first 14 days of ARDS, one meta-analysis demonstrated better survival with corticosteroids. Importantly, the aforementioned studies have methodological limitations, and the number of subjects enrolled was small. Experts differ in their recommendations regarding corticosteroids for late-stage ARDS, although one consensus group supported a 'weak' recommendation of low-to-moderate-dose corticosteroids for ARDS of < 14 days duration. If corticosteroids are administered, infection surveillance, avoidance of neuromuscular blockers, and gradual taper of corticosteroids are recommended. [ABSTRACT FROM AUTHOR]

For many years the greatest barrier to the diagnosis and treatment of obstructive sleep apnea (OSA) was recognizing the disease. That obstacle is now fading as more physicians of all types are aware of the high prevalence of OSA and the consequences of untreated OSA. Sleep-laboratory polysomnography has long been considered the accepted standard for OSA diagnosis and has become a lucrative practice. This, unfortunately, has led to a concentration on diagnosis rather than on management of OSA. Although several brands of portable polysomnograph have been approved for home polysomnography, obstacles to reimbursement (primarily from government, but also from private payers) have prevented widespread home polysomnography. Over the last 2 decades many scientific studies have supported a strong correlation between the findings from home polysomnography and sleep-laboratory polysomnography. However, limited data are available from good outcomes-oriented studies, so controversy surrounds home polysomnography in the diagnosis of OSA. We review the evidence and debate whether sleep studies are appropriately done in the home. [ABSTRACT FROM AUTHOR]

The use of noninvasive ventilation (NIV) for acute respiratory failure has become widespread, but with the newfound beneficial treatments come complications. There is credible although somewhat disparate evidence to support the concept that, compared to invasive ventilation, NIV can reduce the incidence of infectious complications. In selected populations, nosocomial pneumonia appears to be significantly less common with NIV than with endotracheal intubation. NIV complications range from minor (eg, mask-related difficulties) to serious (eg, aspiration and hemodynamic effects). Evidence shows that if NIV is inappropriately applied for too long, the consequences may lead to death, presumably due to excessive delay of intubation. Despite apparently similar costs of treatment for patients with equivalent severity of illness, there is substantially less reimbursement for NIV than for intubation. The use of sedation in NIV patients has not been systematically studied, and sedation is generally underutilized, to avoid complications. Do-not-intubate patients pose a special ethical dilemma with regard to NIV, because NIV may conflict with a preexisting directive not to use life-support measures in the terminally ill patient. [ABSTRACT FROM AUTHOR]

Objective: To critically assess available high-level clinical studies regarding use of noninvasive positive pressure ventilation in varied intensive care unit settings.Data Source: Search of pertinent articles within Ovid MEDLINE from 1975 to 2005, CINAHL from 1982 to 2005, EMBASE from 1988 to 2005, and Web of Science from 1993 to 2005.Study Selection: Randomized, controlled clinical trials and cohort studies and observational studies the authors consider important or novel.Data Extraction/synthesis: Performed equally by both authors with the use of an Excel data spreadsheet.Conclusion: There is abundant level I evidence supporting the use of noninvasive positive pressure ventilation in such critical care settings as acute hypercapnic respiratory failure, particularly related to chronic obstructive pulmonary disease, and acute cardiogenic pulmonary edema. We also report on other clinical scenarios in which the data may be somewhat less compelling, but evidence favors a noninvasive positive pressure ventilation trial. Some well designed studies suggest that noninvasive positive pressure ventilation is not an appropriate intervention for patients who have failed endotracheal extubation. [ABSTRACT FROM AUTHOR]

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is characterized by repetitive episodes of airflow reduction (hypopnea) or cessation (apnea) due to upper airway collapse during sleep. Increasing recognition and a greater understanding of the scope of this condition have substantially affected the practices of many clinicians. This review provides practical information for physicians assessing patients with OSAHS. It discusses complications, clinical recognition, the polysomnographic report, and treatment of OSAHS, including strategies for troubleshooting problems associated with continuous positive airway pressure therapy. [ABSTRACT FROM AUTHOR]

Background: Not all hypercapnic COPD patients benefit from home noninvasive ventilation (NIV), and mechanisms through which NIV improves clinical outcomes remain uncertain. We aimed to identify "responders" to home NIV, denoted by a beneficial effect of NIV on arterial partial pressure of carbon dioxide ( P aCO 2 ), health-related quality of life (HRQoL) and survival, and investigated whether NIV achieves its beneficial effect through an improved P aCO 2 ., Methods: We used individual patient data from previous published trials collated for a systematic review. Linear mixed-effect models were conducted to compare the effect of NIV on P aCO 2 , HRQoL and survival, within subgroups defined by patient and treatment characteristics. Secondly, we conducted a causal mediation analysis to investigate whether the effect of NIV is mediated by a change in P aCO 2 ., Findings: Data of 1142 participants from 16 studies were used. Participants treated with lower pressure support (<14 versus ≥14 cmH 2 O) and with lower adherence (<5 versus ≥5 h·day -1 ) had less improvement in P aCO 2 (mean difference (MD) -0.30 kPa, p<0.001 and -0.29 kPa, p<0.001, respectively) and HRQoL (standardised MD 0.10, p=0.002 and 0.11, p=0.02, respectively), but this effect did not persist to survival. P aCO 2 improved more in patients with severe dyspnoea (MD -0.30, p=0.02), and HRQoL improved only in participants with fewer than three exacerbations (standardised MD 0.52, p=0.03). The results of the mediation analysis showed that the effect on HRQoL is mediated partially (23%) by a change in P aCO 2 ., Interpretation: With greater pressure support and better daily NIV usage, a larger improvement in P aCO 2 and HRQoL is achieved. Importantly, we demonstrated that the beneficial effect of home NIV on HRQoL is only partially mediated through a reduction in diurnal P aCO 2 ., Competing Interests: Conflict of interest: T. Raveling reports a travel grant from Breas Medical. N.S. Hill reports consulting fees from Philips, consulting fees and payments from Fisher & Paykel, and participates in boards of Breas and Philips. C. Casanova reports consulting fees from AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Menarini and Novartis, and participates in boards of AstraZeneca and GlaxoSmithKline. E. Clini reports consulting fees from Chiesi Italia and Novartis, payments from AstraZeneca, Boehringer Ingelheim and GaxoSmithKline, and meeting/travel support from Boehringer Ingelheim and Chiesi. T. Köhnlein reports support from Grifols Deutschland GmbH. P.B. Murphy reports grants and payments from Fisher & Paykel, Resmed, Breas Medical and Philips Respironics, and payments from Chiesi and Genzyme. M.L. Duiverman reports grants from Resmed, Philips, Lowenstein, Vivisol, Sencure and Fisher & Paykel, and payments from Chiesi and Breas Medical. P.J. Wijkstra reports grants from Resmed, and grants and consulting fees from Philips., (Copyright ©The authors 2024.)

Study Objectives: To evaluate whether or not the apnea-hypopnea index (AHI) from a peripheral arterial tonometry (PAT) home sleep apnea test (HSAT) is equivalent to the AHI provided by the mean of one, three, or seven nights from the Withings Sleep Analyzer (WSA) under-mattress device., Methods: We prospectively enrolled patients with suspected OSA in whom a PAT-HSAT was ordered. Eligible patients used the WSA for seven to nine nights. PAT data were scored using the device's intrinsic machine learning algorithms to arrive at the AHI using both 3% and 4% desaturation criteria for hypopnea estimations (PAT3%-AHI and PAT4%-AHI, respectively). These were then compared with the WSA-estimated AHI (WSA-AHI)., Results: Of 61 patients enrolled, 35 completed the study with valid PAT and WSA data. Of the 35 completers 16 (46%) had at least moderately severe OSA (PAT3%-AHI ≥ 15). The seven-night mean WSA-AHI was 2.13 (95%CI =  - 0.88, 5.14) less than the PAT3%-AHI, but 5.64 (95%CI = 2.54, 8.73) greater than the PAT4%-AHI. The accuracy and area under the receiver operating curve (AUC) using the PAT3%-AHI ≥ 15 were 77% and 0.87 and for PAT4%-AHI ≥ 15 were 77% and 0.85, respectively. The one-, three-, or seven-night WSA-AHI were not equivalent to either the 3% or 4% PAT-AHI (equivalency threshold of ± 2.5 using the two one-sided t-test method)., Conclusions: The WSA derives estimates of the AHI unobtrusively over many nights, which may prove to be a valuable clinical tool. However, the WSA-AHI over- or underestimates the PAT-AHI in clinical use, and the appropriate use of the WSA in clinical practice will require further evaluation., Trial Registration: ClinicalTrials.gov Identifier: NCT04778748., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Objective: Excessive daytime sleepiness (EDS) is common in obstructive sleep apnea (OSA) and has been linked to adverse outcomes, albeit inconsistently. Furthermore, whether the prognostic impact of EDS differs as a function of sex is unclear. We aimed to assess the associations between EDS and chronic diseases and mortality in men and women with OSA., Methods: Newly-diagnosed adult OSA patients who underwent sleep evaluation at Mayo Clinic between November 2009 and April 2017 and completed the Epworth Sleepiness Scale (ESS) for assessment of perceived sleepiness ( N  = 14,823) were included. Multivariable-adjusted regression models were used to investigate the relationships between sleepiness, with ESS modeled as a binary (ESS > 10) and as a continuous variable, and chronic diseases and all-cause mortality., Results: In cross-sectional analysis, ESS > 10 was independently associated with lower risk of hypertension in male OSA patients (odds ratio [OR], 95% confidence interval [CI]: 0.76, 0.69-0.83) and with higher risk of diabetes mellitus in both OSA men (OR, 1.17, 95% CI 1.05-1.31) and women (OR 1.26, 95% CI 1.10-1.45). Sex-specific curvilinear relations between ESS score and depression and cancer were noted. After a median 6.2 (4.5-8.1) years of follow-up, the hazard ratio for all-cause death in OSA women with ESS > 10 compared to those with ESS ≤ 10 was 1.24 (95% CI 1.05-1.47), after adjusting for demographics, sleep characteristics and comorbidities at baseline. In men, sleepiness was not associated with mortality., Conclusion: The implications of EDS for morbidity and mortality risk in OSA are sex-dependent, with hypersomnolence being independently associated with greater vulnerability to premature death only in female patients. Efforts to mitigate mortality risk and restore daytime vigilance in women with OSA should be prioritized., Competing Interests: EO is a member of the Board of Directors of the American Academy of Sleep Medicine. VS serves as a consultant for ResMed, Jazz Pharmaceuticals, Bayer, Lilly, Sleep Number, Zoll, Respicardia, and Huxley. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Covassin, Lu, St. Louis, Chahal, Schulte, Mansukhani, Xie, Lipford, Li, Ramar, Caples, Gay, Olson, Silber, Li and Somers.)

This article addresses the issue of patient sleep during hospitalization, which the Society of Anesthesia and Sleep Medicine believes merits wider consideration by health authorities than it has received to date. Adequate sleep is fundamental to health and well-being, and insufficiencies in its duration, quality, or timing have adverse effects that are acutely evident. These include cardiovascular dysfunction, impaired ventilatory function, cognitive impairment, increased pain perception, psychomotor disturbance (including increased fall risk), psychological disturbance (including anxiety and depression), metabolic dysfunction (including increased insulin resistance and catabolic propensity), and immune dysfunction and proinflammatory effects (increasing infection risk and pain generation). All these changes negatively impact health status and are counterproductive to recovery from illness and operation. Hospitalization challenges sleep in a variety of ways. These challenges include environmental factors such as noise, bright light, and overnight awakenings for observations, interventions, and transfers; physiological factors such as pain, dyspnea, bowel or urinary dysfunction, or discomfort from therapeutic devices; psychological factors such as stress and anxiety; care-related factors including medications or medication withdrawal; and preexisting sleep disorders that may not be recognized or adequately managed. Many of these challenges appear readily addressable. The key to doing so is to give sleep greater priority, with attention directed at ensuring that patients' sleep needs are recognized and met, both within the hospital and beyond. Requirements include staff education, creation of protocols to enhance the prospect of sleep needs being addressed, and improvement in hospital design to mitigate environmental disturbances. Hospitals and health care providers have a duty to provide, to the greatest extent possible, appropriate preconditions for healing. Accumulating evidence suggests that these preconditions include adequate patient sleep duration and quality. The Society of Anesthesia and Sleep Medicine calls for systematic changes in the approach of hospital leadership and staff to this issue. Measures required include incorporation of optimization of patient sleep into the objectives of perioperative and general patient care guidelines. These steps should be complemented by further research into the impact of hospitalization on sleep, the effects of poor sleep on health outcomes after hospitalization, and assessment of interventions to improve it., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 International Anesthesia Research Society.)

As more patients depend upon mechanical or electronic technologies for treatment, medical device recalls-like the recent recall of common positive airway pressure treatment devices-impact millions of patients, often causing significant anxiety, extra costs, and interruption of care for patients. When recalls require health care and/durable medical equipment providers to be part of the solution, the burden on practices and businesses can be significant, creating strains on access for new patients and on limited medical supplies. We have observed that having an established and well-organized medical device recall plan in place allows for a rapid response, decreased practice burden, and reduced provider stress. Coupling the organized response with proactive, empathic, and clear communication with patients reduces their anxiety, provides clear directions for how to address the issue constructively, and reduces reactive communications. We share what we believe are key components of a medical device and produce recall procedure as we describe our institutions response in hopes that others can build on these basics as they design their own response plans., Citation: Morgenthaler TI, Linginfelter EA, Gay PC, et al. Rapid response to medical device recalls: an organized patient-centered team effort. J Clin Sleep Med. 2022;18(2):663-667., (© 2022 American Academy of Sleep Medicine.)

The current national coverage determinations (NCDs) for noninvasive ventilation for patients with thoracic restrictive disorders, COPD, and hypoventilation syndromes were formulated in 1998. New original research, updated formal practice guidelines, and current consensus expert opinion have accrued that are in conflict with the existing NCDs. Some inconsistencies in the NCDs have been noted, and the diagnostic and therapeutic technology has also advanced in the last quarter century. Thus, these and related NCDs relevant to bilevel positive airway pressure for the treatment of OSA and central sleep apnea need to be updated to ensure the optimal health of patients with these disorders. To that end, the American College of Chest Physicians organized a multisociety (American Thoracic Society, American Academy of Sleep Medicine, and American Association for Respiratory Care) effort to engage experts in the field to: (1) identify current barriers to optimal care; (2) highlight compelling scientific evidence that would justify changes from current policies incorporating best evidence and practice; and (3) propose suggestions that would form the basis for a revised NCD in each of these 5 areas (thoracic restrictive disorders, COPD, hypoventilation syndromes, OSA, and central sleep apnea). The expert panel met during a 2-day virtual summit in October 2020 and subsequently crafted written documents designed to achieve provision of "the right device to the right patient at the right time." These documents have been endorsed by the participating societies following peer review and publication in CHEST and will be used to inform efforts to revise the current NCDs., (Copyright © 2021 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Background: Noninvasive ventilation (NIV), a form of positive airway pressure (PAP) therapy, is the standard of care for various forms of acute respiratory failure (ARF). Communication impairment is a side effect of NIV, impedes patient care, contributes to distress and intolerance, and potentially increases intubation rates. This study aimed to evaluate communication impairment during CPAP therapy and demonstrate communication device improvement with a standardized protocol., Research Question: How does an oronasal mask affect communication intelligibility? How does use of an NIV communication device change this communication intelligibility?, Study Design and Methods: A single-center randomized controlled trial (36 outpatients with OSA on CPAP therapy) assessed exposure to CPAP 10 cm H 2 O and PAP communication devices (SPEAX, Ataia Medical). Communication impairment was evaluated by reading selected words and sentences for partners to record and were tabulated as %words correct. Each outpatient-partner pair performed three assessments: (1) baseline (conversing normally), (2) mask baseline (conversing with PAP), and (3) randomized to functioning device (conversing with PAP and device) or sham device. After each stage, both outpatients and partners completed Likert surveys regarding perceived intelligibility and comfort., Results: While conversing with PAP, word and sentence intelligibility decreased relatively by 52% (87% vs 41%) and relatively by 57% (94% vs 40%), respectively, compared with normal conversation. Word and sentence intelligibility in the intervention arm increased relatively by 75% (35% vs 61%; P < .001) and by 126% (33% vs 76%; P < .001) higher than the control arm, respectively. The device improved outpatient-perceived PAP comfort relatively by 233% (15% vs 50%, P = .042) and partner-perceived comfort by relatively 245% (20% vs 69%, P = .0074)., Interpretation: Use of this PAP communication device significantly improves both intelligibility and comfort. This is one of the first studies quantifying communication impairment during PAP delivery., Trial Registry: ClinicalTrials.gov; No.: NCT03795753; URL: www.clinicaltrials.gov., (Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Objectives: With over 2 million cases of acute respiratory failure in the United States per year, noninvasive ventilation has become a leading treatment modality, often supplanting invasive mechanical ventilation as the initial treatment of choice. Most acute respiratory failure patients use a full face (oronasal) mask with noninvasive ventilation, which is known to impair communication, but its popularity and benefit has led many providers to accept the communication impairment. Medical staff periodically remove masks to communicate with patients, but patients are often limited to short utterances and risk lung derecruitment upon removal of positive pressure. These problems can lead to noninvasive ventilation failure, which is often linked to worse outcomes than first initiating invasive mechanical ventilation and can lead to increased hospitalization costs., Data Sources: We searched MEDLINE and Google Scholar for "speech," "communication," "impairment," "failure," "complications," "NIPPV," "NIV," and "noninvasive ventilation.", Study Selection: We included articles with patients in acute respiratory failure. We excluded articles for patients using noninvasive ventilation therapy for obstructive sleep apnea., Data Synthesis: Communication impairment has been associated with increasing noninvasive ventilation anxiety (odds ratio, 1.25). Of patients using noninvasive ventilation, 48% require early discontinuation, 22% refuse noninvasive ventilation, and 9% are ultimately intubated. Improvements to communication have been shown to reduce fear and anxiety in invasive mechanical ventilation patients. Analogous communication problems exist with effective solutions in other fields, such as fighter pilot masks, that can be easily implemented to enhance noninvasive ventilation patient care, increase adherence to noninvasive ventilation treatment, and improve patient outcomes., Conclusions: Communication impairment is an underappreciated cause of noninvasive ventilation complications and failure and requires further characterization. Analogous solutions-such as throat microphones and mask-based microphones-that can be easily implemented show potential as cost-effective methods to reduce noninvasive ventilation failure., Competing Interests: Dr. Wong is Chief Medical Officer of Ataia Medical and has received an industry grant for NCT03795753. Dr. Happ holds copyright to the Study of Patient-Nurse Effectiveness with Assisted Communication Strategies (SPEACS-2) online communication training program, no personal earnings. Dr. Happ collaborated with industry on augmentative and alternative communication technology development and testing, as principal investigator in collaboration with Vidatak, LLC on grant number 2R42NR014087-02 as consultant to Voxello on grant number 5R44 NR016406-03S. The remaining authors have disclosed that they do not have any potential conflicts of interest., (Copyright © 2020 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine.)

Purpose of Review: Noninvasive ventilation (NIV) is an established treatment for chronic hypercapnic respiratory failure (CRF). Volume-assured pressure support (VAPS) is a mode of NIV that automatically adjusts inspiratory pressure in order to maintain a constant respiratory volume. We aim to discuss the role and application of VAPS in CRF., Recent Findings: Recently published meta-analyses and reviews fail to demonstrate a significant difference in gas exchange, sleep, or quality-of-life improvement between VAPS and bilevel positive airway pressure (BPAP) in patients with CRF. A recent manuscript suggests that VAPS therapy in chronic obstructive pulmonary disease patients may reduce the number of exacerbations. It has been shown that with a protocol-driven approach BPAP and VAPS can both be successfully titrated during a single split-night polysomnography., Summary: VAPS is as effective as other modes of NIV at improving ventilation and sleep in CRF. The potential advantage is a more consistent ventilatory support through daytime-nighttime variations and progression of disease over time. However, the impact on long-term outcomes, such as survival, has not been studied.

Citation: Javaheri S, Gay PC. To die, to sleep - to sleep, perchance to dream…without hypertension: dreams of the visionary Christian Guilleminault revisited. J Clin Sleep Med. 2019;15(9):1189-1190., (© 2019 American Academy of Sleep Medicine.)

Study Objectives: Adaptive servoventilation (ASV) is the suggested treatment for many forms of central sleep apnea (CSA). We aimed to evaluate the impact of treating CSA with ASV on health care utilization., Methods: In this population-based study using the Rochester Epidemiology Project database, we identified patients over a 9-year period who were diagnosed with CSA (n = 1,237), commenced ASV therapy, and had ≥ 1 month of clinical data before and after ASV initiation. The rates of hospitalizations, emergency department visits (EDV), outpatient visits (OPV) and medications prescribed per year (mean ± standard deviation) in the 2 years pre-ASV and post-ASV initiation were compared., Results: We found 309 patients (68.0 ± 14.6 years, 80.3% male, apnea-hypopnea index 41.6 ± 26.5 events/h, 78% with cardiovascular comorbidities, 34% with heart failure) who met inclusion criteria; 65% used ASV ≥ 4 h/night on ≥ 70% nights in their first month. The overall 2-year mortality rate was 9.4% and CSA secondary to cardiac cause was a significant risk factor for mortality (hazard ratio 1.81, 95% CI 1.09-3.01, P = .02). Comparing pre-ASV and post-ASV initiation, there was no change in the rate of hospitalization (0.72 ± 1.63 versus 0.79 ± 1.44, P = .46), EDV (1.19 ± 2.18 versus 1.26 ± 2.08, P = .54), OPV (31.59 ± 112.42 versus 13.60 ± 17.36, P = .22), or number of prescribed medications (6.68 ± 2.0 versus 5.31 ± 5.86, P = .06). No differences in these outcomes emerged after accounting for adherence to ASV, CSA subtype and comorbidities via multiple regression analysis (all P > .05)., Conclusions: Our cohort of patients with CSA was quite ill and the use of ASV was not associated with a change in health care utilization., (© 2019 American Academy of Sleep Medicine.)

Acute respiratory compromise describes a deterioration in respiratory function with a high likelihood of rapid progression to respiratory failure and death. Identifying patients at risk for respiratory compromise coupled with monitoring of patients who have developed respiratory compromise might allow earlier interventions to prevent or mitigate further decompensation. The National Association for the Medical Direction of Respiratory Care (NAMDRC) organized a workshop meeting with representation from many national societies to address the unmet needs of respiratory compromise from a clinical practice perspective. Respiratory compromise may arise de novo or may complicate preexisting lung disease. The group identified distinct subsets of respiratory compromise that present similar opportunities for early detection and useful intervention to prevent respiratory failure. The subtypes were characterized by the pathophysiological mechanisms they had in common: impaired control of breathing, impaired airway protection, parenchymal lung disease, increased airway resistance, hydrostatic pulmonary edema, and right-ventricular failure. Classification of acutely ill respiratory patients into one or more of these categories may help in selecting the screening and monitoring strategies that are most appropriate for the patient's particular pathophysiology. Standardized screening and monitoring practices for patients with similar mechanisms of deterioration may enhance the ability to predict respiratory failure early and prevent its occurrence., (Copyright © 2017 by Daedalus Enterprises.)

Although precise numbers are difficult to obtain, the population of patients receiving long-term ventilation has increased over the last 20 years, and includes patients with chronic lung diseases, neuromuscular diseases, spinal cord injury, and children with complex disorders. This article reviews the equipment and logistics involved with ventilation outside of the hospital. Discussed are common locations for long-term ventilation, airway and secretion management, and many of the potential challenges faced by individuals on long-term ventilation., (Published by Elsevier Inc.)

Chronic obstructive pulmonary disease (COPD) is a common disease affecting about 20 million US adults. Sleep-disordered breathing (SDB) problems are frequent and poorly characterized for patients with COPD. Both the well-known success of noninvasive ventilation (NIV) in the acute COPD exacerbation in the hospital setting and that NIV is the cornerstone of chronic therapy for SDBs have urged the attention of the medical community to determine the impact of NIV on chronic COPD management with and without coexisting SDBs. Early observational studies showed decreased long-term survival rates on patients with COPD with concomitant chronic hypercapnia when compared with normocapnic patients., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Introduction: Obstructive sleep apnea (OSA) may increase the incidence of postoperative complications when undiagnosed. The purpose of this study was to evaluate the perspectives of Canadian anesthesiologists regarding the perioperative management of patients with diagnosed or suspected OSA., Methods: This study was conducted as a survey of Canadian anesthesiologists using a self-administered scenario-based questionnaire. We initially mailed the survey questionnaire and then mailed it again to non-respondents six weeks later. Subsequently, we e-mailed the online version of our survey to active members of the Canadian Anesthesiologists' Society., Results: The response rates were 35% and 26% for the postal and online modes of administration, respectively. About 50% of the respondents relied on clinical suspicion rather than on a systematic screening to identify patients who may have undiagnosed OSA preoperatively. Forty-seven percent of all respondents either did not know of any institutional policy to guide their perioperative management of patients with OSA or reported an absence of an institutional policy. Fifteen percent of the respondents would discharge diagnosed OSA inpatients with compliant use of continuous positive airway pressure (CPAP) to the ward without monitoring. Nevertheless, a more conservative approach was observed for CPAP non-compliant inpatients. We indeed observed that more than 40% of respondents would send an ambulatory OSA patient home, while another 60% would favour hospital admission., Conclusions: The majority of anesthesiologists continue to rely on clinical suspicion alone to identify OSA. Moreover, the lack of institutional policy is concerning. A concerted effort to develop an evidence-based guideline may be the next step to assist institutions.

CPAP therapy has remained the standard of care for the treatment of sleep apnea for nearly 4 decades. Its overall effectiveness, however, has been limited by incomplete adherence despite many efforts to improve comfort. Conventional alternative therapies include oral appliances and upper airway surgeries. Recently, several innovative alternatives to CPAP have been developed. These novel approaches include means to increase arousal thresholds, electrical nerve stimulation, oral vacuum devices, and nasal expiratory resistive devices. We will review the physiologic mechanisms and the current evidence for these novel treatments.

Background: Continuous positive airway pressure (CPAP) is considered the treatment of choice for obstructive sleep apnea (OSA), and studies have shown that there is a correlation between patient adherence and treatment outcomes. Newer CPAP machines can track adherence, hours of use, mask leak, and residual apnea-hypopnea index (AHI). Such data provide a strong platform to examine OSA outcomes in a chronic disease management model. However, there are no standards for capturing CPAP adherence data, scoring flow signals, or measuring mask leak, or for how clinicians should use these data., Methods: American Thoracic Society (ATS) committee members were invited, based on their expertise in OSA and CPAP monitoring. Their conclusions were based on both empirical evidence identified by a comprehensive literature review and clinical experience., Results: CPAP usage can be reliably determined from CPAP tracking systems, but the residual events (apnea/hypopnea) and leak data are not as easy to interpret as CPAP usage and the definitions of these parameters differ among CPAP manufacturers. Nonetheless, ends of the spectrum (very high or low values for residual events or mask leak) appear to be clinically meaningful., Conclusions: Providers need to understand how to interpret CPAP adherence tracking data. CPAP tracking systems are able to reliably track CPAP adherence. Nomenclature on the CPAP adherence tracking reports needs to be standardized between manufacturers and AHIFlow should be used to describe residual events. Studies should be performed examining the usefulness of the CPAP tracking systems and how these systems affect OSA outcomes.

Background: Obstructive sleep apnea has been associated with postoperative complications. We hypothesized that postoperative autotitrating positive airway pressure (APAP) applied to patients at high risk for obstructive sleep apnea would shorten hospital stay and reduce postoperative complications., Methods: Included were patients aged 18 to 100 years scheduled for elective total knee or hip arthroplasty who were able to give informed consent. Patients without contraindication to positive airway pressure therapy were divided into a high- or low-risk group on the basis of the Flemons sleep apnea clinical score. Low-risk patients received standard care. High-risk patients were randomized to receive standard care or standard care plus postoperative APAP. All patients were administered a predismissal cardiorespiratory sleep study. The primary end point was length of stay, and secondary end points were a range of postoperative complications., Results: One hundred thirty-eight patients were enrolled in the study (52 in the low-risk group, 86 in the high-risk group). Within the high-risk group, 43 were randomized to standard care and 43 to standard care plus postoperative APAP. There were no significant differences in the length of stay (P=.65) or any of the secondary end points between the randomized groups. On subgroup analysis of patients with an apnea-hypopnea index of ≥15, patients randomized to APAP had a longer postoperative stay (median, 5 vs 4 days; P=.02)., Conclusions: The role for empirical postoperative APAP requires further study, but the findings did not show benefit for APAP applied postoperatively to positive airway pressure-naive patients at high risk for sleep apnea.

Background: Patients with do-not-intubate (DNI) status and respiratory failure are commonly treated with noninvasive ventilation (NIV). High-flow nasal cannula (HFNC) therapy supplies a high flow of heated and humidified oxygen that may provide an effective alternative to NIV. We assessed the efficacy of HFNC in DNI patients with hypoxemic respiratory distress., Methods: We identified 50 DNI patients with hypoxemic respiratory distress who were admitted to a medical ICU and who received HFNC. We excluded patients with PaCO2 > 65 mm Hg and pH < 7.28. The primary end point was the need for escalation to NIV, as determined by the primary service. Mean changes in oxygen saturation and breathing frequency before and after HFNC were compared., Results: The subjects included 25 men and 25 women, mean age 73 years (range 27-96 y). Diagnoses (allowing multiple conditions) included pulmonary fibrosis (15), pneumonia (15), COPD (12), cancer (7), hematologic malignancy (7), and congestive heart failure (3). Hospital mortality was 60% (30/50). HFNC was initiated at a mean FIO2 of 0.67 (range 0.30-1.0) and flow of 42.6 L/min (range 30-60 L/min). Mean O2 saturations went from 89.1% to 94.7% (P < .001), and breathing frequency went from 30.6 breaths/min to 24.7 breaths/min (P < .001). Nine of the 50 subjects (18%) escalated to NIV, while 82% were maintained on HFNC. The median duration of HFNC was 30 hours (range 2-144 h)., Conclusions: HFNC can provide adequate oxygenation for many patients with hypoxemic respiratory failure and may be an alternative to NIV for DNI patients.

Background: Obstructive sleep apnoea (OSA) is often undiagnosed before elective surgery and may predispose patients to perioperative complications., Methods: A literature search of PubMed-Medline, Web of Science, Scopus, EMBASE, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials up to November 2010 was conducted. Our search was restricted to cohort or case-control studies in adults diagnosed with OSA by screening questionnaire, oximetry, or polysomnography. Studies without controls, involving upper airway surgery, and with OSA diagnosed by ICD-9 codes alone were excluded. The primary postoperative outcomes were desaturation, acute respiratory failure (ARF), reintubation, myocardial infarction/ischaemia, arrhythmias, cardiac arrest, intensive care unit (ICU) transfer, and length of stay., Results: Thirteen studies were included in the final analysis (n=3942). OSA was associated with significantly higher odds of any postoperative cardiac events [45/1195 (3.76%) vs 24/1420 (1.69%); odds ratio (OR) 2.07; 95% confidence interval (CI) 1.23-3.50, P=0.007] and ARF [33/1680 (1.96%) vs 24/3421 (0.70%); OR 2.43, 95% CI 1.34-4.39, P=0.003]. Effects were not heterogeneous for these outcomes (I(2)=0-15%, P>0.3). OSA was also significantly associated with higher odds of desaturation [189/1764 (10.71%) vs 105/1881 (5.58%); OR 2.27, 95% CI 1.20-4.26, P=0.01] and ICU transfer [105/2062 (5.09%) vs 58/3681 (1.57%), respectively; OR 2.81, 95% CI 1.46-5.43, P=0.002]. Both outcomes showed a significant degree of heterogeneity of the effect among studies (I(2)=57-68%, P<0.02). Subgroup analyses had similar conclusions as main analyses., Conclusions: The incidence of postoperative desaturation, respiratory failure, postoperative cardiac events, and ICU transfers was higher in patients with OSA.

Study Objectives: We hypothesized that early intervention with an auto bilevel device would improve treatment adherence compared to CPAP among OSA patients with a poor initial experience with lab-based CPAP titration., Methods: Patients with a poor initial CPAP experience were recruited for this parallel group, randomized, double-blind, controlled pilot study. After an in-lab titration, patients were randomized with either an auto-bilevel device or CPAP. Treatment adherence and functioning were assessed at 90 days., Results: We enrolled 51 subjects, with 47 completing the protocol. Groups were equally matched for gender, age, education, and OSA severity. There was no significant difference in the proportion of compliant subjects (≥ 4 h/night) between the auto bilevel and CPAP groups (62% vs. 54%; p = 0.624) after 90 days of use. Functional outcomes significantly improved in both groups during treatment use (p < 0.001) but did not differ between groups., Conclusions: There was no statistically significant difference in adherence between the auto bilevel and CPAP groups in this study. Patients with a poor initial CPAP exposure may still achieve an acceptable long-term clinical outcome. Both groups demonstrated comparably significant improvements in functional outcomes, sleepiness, and fatigue complaints over the treatment period. CLINICAL TRIALS INFORMATION: NCT00635206 ClinicalTrials.gov

Background: An increasing number of patients require prolonged mechanical ventilation (PMV), which is associated with high morbidity and poor long-term survival, but there are few data regarding the incidence and outcome of PMV patients from a community perspective., Methods: We retrospectively reviewed the electronic medical records of adult Olmsted county, Minnesota, residents admitted to the intensive care units at the 2 Mayo Clinic Rochester hospitals from January 1, 2003, to December 31, 2007, who underwent tracheostomy for PMV., Results: Sixty-five patients, median age 68 years (interquartile range [IQR] 49-80 y), 39 male, underwent tracheostomy for PMV, resulting in an age-adjusted incidence of 13 (95% CI 10-17) per 100,000 patient-years at risk. The median number of days on mechanical ventilation was 24 days (IQR 18-37 d). Forty-six patients (71%) survived to hospital discharge, and 36 (55%) were alive at 1-year follow-up. After adjusting for age and baseline severity of illness, the presence of COPD was independently associated with 1-year mortality (hazard ratio 3.4, 95% CI 1.4-8.2%)., Conclusions: There was a considerable incidence of tracheostomy for PMV. The presence of COPD was an independent predictor of 1-year mortality.

Background: Patients with obstructive sleep apnea are at risk for perioperative morbidity. The authors used a screening prediction model for obstructive sleep apnea to generate a sleep apnea clinical score (SACS) that identified patients at high or low risk for obstructive sleep apnea. This was combined with postanesthesia care unit (PACU) monitoring with the aim of identifying patients at high risk of postoperative oxygen desaturation and respiratory complications., Methods: In this prospective cohort study, surgical patients with a hospital stay longer than 48 h who consented were enrolled. The SACS (high or low risk) was calculated; all patients were monitored in the PACU for recurrent episodes of bradypnea, apnea, desaturations, and pain-sedation mismatch. All patients underwent pulse oximetry postoperatively; complications were documented. Chi-square, two-sample t test, and logistic regression were used for analysis. The oxygen desaturation index (number of desaturations per hour) was calculated. Oxygen desaturation index and incidence of postoperative cardiorespiratory complications were primary endpoints., Results: Six hundred ninety-three patients were enrolled. From multivariable logistic regression analysis, the likelihood of a postoperative oxygen desaturation index greater than 10 was increased with a high SACS (odds ratio = 1.9, P < 0.001) and recurrent PACU events (odds ratio = 1.5, P = 0.036). Postoperative respiratory events were also associated with a high SACS (odds ratio = 3.5, P < 0.001) and recurrent PACU events (odds ratio = 21.0, P < 0.001)., Conclusions: Combination of an obstructive sleep apnea screening tool preoperatively (SACS) and recurrent PACU respiratory events was associated with a higher oxygen desaturation index and postoperative respiratory complications. A two-phase process to identify patients at higher risk for perioperative respiratory desaturations and complications may be useful to stratify and manage surgical patients postoperatively.

Patients with complex sleep apnea syndrome (CompSAS) have obstructive sleep apnea but develop troublesome central sleep apnea activity or Cheyne-Stokes breathing when provided continuous positive airway pressure (CPAP) therapy. We examined whether CompSAS activity persists with long-term CPAP treatment. We retrospectively identified all patients with CompSAS who underwent two therapeutic polysomnograms (PSGs) separated by at least 1 month during 2003-2005. We compared PSG findings between the initial and follow-up study and noted clinical responses to therapy. We identified 13 CompSAS patients meeting criteria. Most follow-up PSGs were ordered after an abnormal overnight oximetry on CPAP or because of CPAP intolerance after 195 (49-562) days. The residual apnea-hypopnea index (AHI) on CPAP decreased from 26 (23-40) on the first PSG to 7 (3-21.5) on the follow-up PSG. Only seven patients reached AHI < 10 and 6 had AHI > or = 10 ("CPAP nonresponders") at follow-up. "CPAP nonresponders" were sleepier (Epworth Sleepiness Score 13 [12.5-14] vs 9 [6-9.5], p = 0.03) and trended toward lower body mass index (29.7 [28.6-31.6] vs 34.3 [32.5-35.1], p = 0.06). Both groups were equally compliant with CPAP therapy. Although the AHI tends to improve over time in CompSAS patients treated with CPAP, in this retrospective study nearly half-maintained a persistently elevated AHI. A prospective trial is merited to determine the optimal treatment for these patients.

Study Objectives: Despite widespread agreement that continuous positive airway pressure is effective therapy for obstructive sleep apnea, it is estimated that 50% of patients recommended for therapy are noncompliant 1 year later. Interventions to improve compliance in such patients have not been studied. We evaluated a 2 phase intervention program to improve compliance in sleep apnea patients previously noncompliant with continuous positive airway pressure., Methods: 204 patients with previously diagnosed obstructive sleep apnea and noncompliant with continuous positive airway pressure were enrolled. Phase 1 evaluated standard interventions to improve therapy compliance, including mask optimization, heated humidification, topical nasal therapy, and sleep apnea education. Persistently noncompliant patients proceeded to phase 2, where compliance was compared in double-blind randomized fashion between standard continuous positive airway pressure and flexible bilevel positive airway pressure., Results: 49 (24%) of 204 previously noncompliant patients became compliant (average nightly use > or =4 hours) after standard interventions. Then 104 of the 155 persistently noncompliant patients agreed to continue and were randomized to either CPAP or flexible bilevel positive airway pressure retitration and treatment for an additional ninety days. At follow-up 15 (28%) of the 53 randomized to CPAP and 25 (49%) of the 51 randomized to flexible bilevel positive airway pressure (p = 0.03) achieved compliance., Conclusions: A two phase intervention program, first employing standard interventions, followed by a change to flexible bilevel airway pressure, can achieve improved compliance in patients previously noncompliant with continuous positive airway pressure.

Background: Complex sleep apnea syndrome (CompSAS) is recognized by the concurrence of mixed or obstructive events with central apneas, the latter predominating on exposure to continuous positive airway pressure (CPAP). Treatment of CompSAS or central sleep apnea (CSA) syndrome with adaptive servoventilation (ASV) is now an option, but no large series exist describing the application and effectiveness of ASV., Methods: Retrospective chart review of the first 100 patients who underwent polysomnography using ASV at Mayo Clinic Sleep Center., Results: ASV titration was performed for CompSAS (63%), CSA (22%), or CSA/Cheyne Stokes breathing patterns (15%). The median diagnostic sleep apnea hypopnea index (AHI) was 48 events per hour (range, 24 to 62). With CPAP, obstructive apneas decreased, but the appearance of central apneas maintained the AHI at 31 events per hour (range, 17 to 47) [p = 0.02]. With bilevel positive airway pressure (BPAP) in spontaneous mode, AHI trended toward worsening vs baseline, with a median of 75 events per hour (range, 46 to 111) [p = 0.055]. BPAP with a backup rate improved the AHI to 15 events per hour (range, 11 to 31) [p = 0.002]. Use of ASV dramatically improved the AHI to a mean of 5 events per hour (range, 1 to 11) vs baseline and vs CPAP (p < 0.0001). ASV also resulted in an increase in rapid eye movement sleep vs baseline and CPAP (18% vs 12% and 10%, respectively; p < 0.0001). Overall, 64 patients responded to the ASV treatment with a mean AHI < 10 events per hour. Of the 44 successful survey follow-up patients contacted, 32 patients reported some improvement in sleep quality., Conclusion: The ASV device appears to be an effective treatment of both CompSAS and CSA syndromes that are resistant to CPAP.

Study Objectives: Obstructive sleep apnea (OSA) has been associated with increased perioperative morbidity and mortality. We initiated a protocol designed to screen patients preoperatively and monitor them postoperatively. The goal was to identify patients who were at risk for oxygen desaturation after discharge from the postanesthesia recovery room (PACU)., Methods: Patients without previously diagnosed OSA presenting to the preoperative evaluation clinic were assessed over a 10.5-month period using a validated prediction rule to identify patients thought to be at high risk of OSA (sleep apnea clinical score, SACS > or = 15). Following surgery, patients were monitored in the PACU for significant respiratory events: apnea, increased FiO2 requirement, pain-sedation mismatch, or episodes of desaturation. Patients were placed in 3 groups based on their SACS and the presence or absence of recurrent PACU respiratory events (group 1: SACS < 15, no recurrent events; group 2: SACS > or =15, no recurrent events; and group 3: SACS > or = 15, recurrent events.) The number of oxygen desaturations > or = 4% per hour, the oxygen desaturation index (ODI), was calculated for each patient for 24 to 48 hours after PACU discharge. An ODI > 10 was the threshold chosen to indicate a high frequency of oxygen desaturation., Results: The percentage of patients with ODI > 10 differed significantly across the 3 study groups (12%, 37%, and 57%, for groups 1-3, p = 0.005). Mean ODI in group 1 was significantly different from groups 2 and 3 (5.8 compared to 10.0 group 2 and 11.4 group 3 with p = 0.001)., Conclusions: We have shown that combining preoperative screening is useful for identifying patients at risk for oxygen desaturation after PACU discharge.

As modern health care continues to evolve, we expect and are seeing that more sophisticated medical care will be provided outside the traditional acute care environments. Advances in home medical technology, economic pressures, health-care consumerism, and societal changes are all factors playing a role in this evolution. Medically fragile and technology-dependent individuals who were once limited to care in acute and subacute institutional settings are now frequently cared for at home, most often by their immediate family members. Mechanical ventilation has found its way into the patient's home such that physicians and other providers must be prepared for the challenges associated with managing the conditions of complex, ventilator-dependent individuals outside of the walls, controls, and safety of the institutional setting. With little published science and recognized standards of practice, there are fewer rules to guide clinicians through this process. Experience has shown, however, that successful home management of ventilator-dependent individuals can be traced to a smooth and collaborative discharge from the hospital to home. Reimbursement and coverage issues must also be well understood to avoid the aggravation of denials and challenges for necessary equipment and assistance. Once home, a streamlined, patient-centered process supported by effective communication between all care providers can result in a safe and appropriate long-term home ventilation success story.

Background and Purpose: Some patients with obstructive sleep apnea syndrome (OSAS) develop problematic central apneas or Cheyne-Stokes pattern with acute application of continuous positive airway pressure (CPAP), herein called complex sleep apnea syndrome (CompSAS). This response makes it difficult to be certain that CPAP will be a successful treatment strategy. We sought to compare treatments between patients with CompSAS vs. OSAS and hypothesized that CompSAS patients would find CPAP less effective and have more problems with adherence than patients with OSAS., Patients and Methods: We performed a retrospective review of patients studied in our sleep disorders center over 1 month., Results: There were 133 patients with OSAS (mean age=57.6+/-12.2 years; males=63.9%) and 34 with CompSAS (mean age=54.4+/-16 years; males=82.35%). CPAP was prescribed in 93.7 and 87.9% of OSAS and CompSAS patients, respectively (P=0.284), with no significant difference in required CPAP pressures (P=0.112). There was no difference in prescription frequency of alternative therapies. Mean time to the first follow-up was shorter in CompSAS patients (46.2+/-47.3 vs. 53.8+/-36.8 days; P=0.022). CPAP compliance in OSAS and CompSAS patients (5.1+/-1.6 vs. 6.1+/-1.5h, P=0.156) and improvement in Epworth Sleepiness Scale (ESS) (-4.6+/-4.8 vs. -5.9+/-6.9, P=0.483) was similar. However, interface problems were more common in CompSAS patients, especially air hunger/dyspnea (0.8 vs. 8.8%) and inadvertent mask removal (2.6 vs. 17.7%) (all P<0.050)., Conclusion: CompSAS patients have more CPAP interface problems and require more follow-up than OSAS patients but with intervention may have similar treatment results compared to patients with OSAS.

Introduction: The role of non-invasive positive pressure ventilation (NIPPV) in the treatment of acute lung injury (ALI) is controversial. We sought to assess the outcome of ALI that was initially treated with NIPPV and to identify specific risk factors for NIPPV failure., Methods: In this observational cohort study at the two intensive care units of a tertiary center, we identified consecutive patients with ALI who were initially treated with NIPPV. Data on demographics, APACHE III scores, degree of hypoxemia, ALI risk factors and NIPPV respiratory parameters were recorded. Univariate and multivariate regression analyses were performed to identify risk factors for NIPPV failure., Results: Of 79 consecutive patients who met the inclusion criteria, 23 were excluded because of a do not resuscitate order and two did not give research authorization. Of the remaining 54 patients, 38 (70.3%) failed NIPPV, among them all 19 patients with shock. In a stepwise logistic regression restricted to patients without shock, metabolic acidosis (odds ratio 1.27, 95% confidence interval (CI) 1.03 to 0.07 per unit of base deficit) and severe hypoxemia (odds ratio 1.03, 95%CI 1.01 to 1.05 per unit decrease in ratio of arterial partial pressure of O2 and inspired O2 concentration--PaO2/FiO2) predicted NIPPV failure. In patients who failed NIPPV, the observed mortality was higher than APACHE predicted mortality (68% versus 39%, p < 0.01)., Conclusion: NIPPV should be tried very cautiously or not at all in patients with ALI who have shock, metabolic acidosis or profound hypoxemia.