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Purpose: To determine whether tidal volume/predicted body weight (TV/PBW) or driving pressure (DP) are associated with mortality in a heterogeneous population of hypoxic mechanically ventilated patients. Methods: A retrospective cohort study involving 18 intensive care units included consecutive patients ≥18 years old, receiving mechanical ventilation for ≥3 days, with a PaO2/FiO2 ratio ≤300 mmHg, whether or not they met full criteria for ARDS. The main outcome was hospital mortality. Multiple logistic regression (MLR) incorporated TV/PBW, DP, and potential confounders including age, APACHE IVa® predicted hospital mortality, respiratory system compliance (CRS), and PaO2/FiO2. Predetermined strata of TV/PBW were compared using MLR. Results: Our cohort comprised 5,167 patients with mean age 61.9 years, APACHE IVa® score 79.3, PaO2/FiO2 166 mmHg and CRS 40.5 ml/cm H2O. Regression analysis revealed that patients receiving DP one standard deviation above the mean or higher (≥19 cmH20) had an adjusted odds ratio for mortality (ORmort) = 1.10 (95% CI: 1.06–1.13, p = 0.009). Regression analysis showed a U-shaped relationship between strata of TV/PBW and adjusted mortality. Using TV/PBW 4–6 ml/kg as the referent group, patients receiving >10 ml/kg had similar adjusted ORmort, but those receiving 6–7, 7–8 and 8–10 ml/kg had lower adjusted ORmort (95%CI) of 0.81 (0.65–1.00), 0.78 (0.63–0.97) and 0.80 0.67–1.01) respectively. The adjusted ORmort in patients receiving 4–6 ml/kg was 1.26 (95%CI: 1.04–1.52) compared to patients receiving 6–10 ml/kg. Conclusions: Driving pressures ≥19 cmH2O were associated with increased adjusted mortality. TV/PBW 4-6ml/kg were used in less than 15% of patients and associated with increased adjusted mortality compared to TV/PBW 6–10 ml/kg used in 82% of patients. Prospective clinical trials are needed to prove whether limiting DP or the use of TV/PBW 6–10 ml/kg versus 4–6 ml/kg benefits mortality. [ABSTRACT FROM AUTHOR]

Introduction: Both types of sleep-disordered breathing (SDB), obstructive and central sleep apnoea (OSA and CSA, respectively), are common in patients with heart failure and reduced ejection fraction (HFrEF). In such patients, SDB is associated with increased cardiovascular morbidity and mortality but it remains uncertain whether treating SDB by adaptive servo-ventilation (ASV) in such patients reduces morbidity and mortality.Aim: ADVENT-HF is designed to assess the effects of treating SDB with ASV on morbidity and mortality in patients with HFrEF.Methods: ADVENT-HF is a multicentre, multinational, randomized, parallel-group, open-label trial with blinded assessment of endpoints of standard medical therapy for HFrEF alone vs. with the addition of ASV in patients with HFrEF and SDB. Patients with a history of HFrEF undergo echocardiography and polysomnography. Those with a left ventricular ejection fraction ≤45% and SDB (apnoea-hypopnoea index ≥15) are eligible. SDB is stratified into OSA with ≥50% of events obstructive or CSA with >50% of events central. Those with OSA must not have excessive daytime sleepiness (Epworth score of ≤10). Patients are then randomized to receive or not receive ASV. The primary outcome is the composite of all-cause mortality, cardiovascular hospital admissions, new-onset atrial fibrillation requiring anti-coagulation but not hospitalization, and delivery of an appropriate discharge from an implantable cardioverter-defibrillator not resulting in hospitalization during a maximum follow-up time of 5 years.Conclusion: The ADVENT-HF trial will help to determine whether treating SDB by ASV in patients with HFrEF improves morbidity and mortality. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Over the past few decades, continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea has evolved into more and more sophisticated modes of therapy for various forms of sleep-disordered breathing. While the principles of splinting the airway and delivering assisted ventilation underpin the basics of this therapy, the introduction of newer technologies and miniaturization are revolutionizing the former conventions of the field. The purpose of this review is to improve our understanding of various forms of PAP therapy by providing the rationale for such modalities, gaining a basic working knowledge of device technology, and critically assessing the clinical research evidence while identifying barriers to implementation. Dissemination of such information is vital in order to prevent knowledge gaps in healthcare providers and systems. [ABSTRACT FROM AUTHOR]

Noninvasive ventilation with pressure support (NIV-PS) therapy can augment ventilation; however, such therapy is fixed and may not adapt to varied patient needs. We tested the hypothesis that in patients with chronic respiratory insufficiency, a newer mode of ventilation [averaged volume assured pressure support (AVAPS)] and lateral decubitus position were associated with better sleep efficiency than NIV-PS and supine position. Our secondary aim was to assess the effect of mode of ventilation, body position, and sleep–wakefulness state on minute ventilation $$ (\dot{V}_{E} ) $$ in the same patients. Single-blind, randomized, cross-over, prospective study. Academic institution. Twenty-eight patients. NIV-PS or AVAPS therapy. Three sleep studies were performed in each patient; prescription validation night, AVAPS or NIV-PS, and crossover to alternate mode. Sleep was not different between AVAPS and NIV-PS. Supine body position was associated with worse sleep efficiency than lateral decubitus position (77.9 ± 22.9 and 85.2 ± 10.5%; P = 0.04). $$ \dot{V}_{E} $$ was lower during stage 2 NREM and REM sleep than during wakefulness ( P < 0.0001); was lower during NIV-PS than AVAPS ( P = 0.029); tended to be lower with greater body mass index ( P = 0.07), but was not influenced by body position. In patients with chronic respiratory insufficiency, supine position was associated with worse sleep efficiency than the lateral decubitus position. AVAPS was comparable to NIV-PS therapy with regard to sleep, but statistically greater $$ \dot{V}_{E} $$ during AVAPS than NIV-PS of unclear significance was observed. $$ \dot{V}_{E} $$ was determined by sleep–wakefulness state, body mass index, and mode of therapy. [ABSTRACT FROM AUTHOR]

This review focuses on the adverse effects of sleep derangements on physicians and patients in the intensive care unit. Recent evidence suggests that the complexity and level of care delivered in the intensive care unit (ICU) has outstripped a trainee's ability to forego sleep and is compromising both physician and patient safety and thereby threatens the foundation of the profession. Sleepy physicians are not only more capable of committing medical errors, but are also more likely to suffer motor vehicle crashes, workplace conflicts, and occupational injuries. Moreover, critically ill patients may suffer from sleep derangements due to a host of factors that includes mechanical ventilation, ICU noise levels, and healthcare activities, although a majority of sleep disturbances in this population are as yet unexplained. Besides suffering at the hands of sleepy physicians, critically ill patients may experience adverse outcomes due to severe sleep derangements during their ICU stay. In conclusion, both critically ill patients and intensive care physicians are susceptible to sleep deprivation and derangements that may ultimately adversely influence patient outcomes. Administrators of an ICU need to be cognizant of the effect of sleep, or lack thereof, on patient and physician safety. Researchers in the areas of sleep medicine and critical care need to collaborate on furthering our understanding of this emerging area of study. [ABSTRACT FROM AUTHOR]

Background: Hospitalization of patients with chronic obstructive pulmonary disease creates a huge healthcare burden. Positive airway pressure therapy is sometimes used in patients with chronic obstructive pulmonary disease, but the possible impact on hospitalization risk remains controversial. We studied the hospitalization risk of patients with chronic obstructive pulmonary disease before and after initiation of various positive airway pressure therapies in a "real-world" bioinformatics study.Methods: We performed a retrospective analysis of administrative claims data of hospitalizations in patients with chronic obstructive pulmonary disease who received or did not receive positive airway pressure therapy: continuous positive airway pressure, bilevel positive airway pressure, and noninvasive positive pressure ventilation using a home ventilator.Results: The majority of 1,881,652 patients with chronic obstructive pulmonary disease (92.5%) were not receiving any form of positive airway pressure therapy. Prescription of bilevel positive airway pressure (1.5%), continuous positive airway pressure (5.6%), and noninvasive positive pressure ventilation (<1%) in patients with chronic obstructive pulmonary disease demonstrated geographic-, sex-, and age-related variability. After adjusting for confounders and propensity score, noninvasive positive pressure ventilation (odds ratio [OR], 0.19; 95% confidence interval [CI], 0.13-0.27), bilevel positive airway pressure (OR, 0.42; 95% CI, 0.39-0.45), and continuous positive airway pressure (OR, 0.70; 95% CI, 0.67-0.72) were individually associated with lower hospitalization risk in the 6 months post-treatment when compared with the 6 months pretreatment but not when compared with the baseline period between 12 and 6 months before treatment initiation. Stratified analysis suggests that comorbid sleep-disordered breathing, chronic respiratory failure, heart failure, and age less than 65 years were associated with greater benefits from positive airway pressure therapy.Conclusion: Initiation of positive airway pressure therapy was associated with reduction in hospitalization among patients with chronic obstructive pulmonary disease, but the causality needs to be determined by randomized controlled trials. [ABSTRACT FROM AUTHOR]

Background: Sleep quality and quantity are severely reduced in critically ill patients receiving mechanical ventilation with a potential for adverse consequences. Our objective was to synthesize the randomized controlled trials (RCTs) that measured the efficacy of sleep-promoting interventions on sleep quality and quantity in critically ill patients.Methods: We included RCTs that objectively measured sleep with electroencephalography or its derivatives and excluded observational studies and those that measured sleep by subjective reports. The research was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.Results: Of 6022 studies identified, 13 met eligibility criteria involving 296 critically ill patients. Eight trials looked at different modes of mechanical ventilation as sleep interventions, and the remaining 5 involved pharmacologic, nonpharmacologic, or environmental interventions. Meta-analysis of the studies revealed that sleep-promoting interventions improved sleep quantity (pooled standardized mean difference [SMD], 0.37; 95% confidence interval [CI], 0.05-0.69; P = .02) and sleep quality through reduction in sleep fragmentation (SMD, -0.31; 95% CI, -0.60 to -0.01; P = .04). Subgroup analysis revealed that timed modes of ventilation improved sleep quantity when compared with spontaneous modes of ventilation (SMD, 0.45; 95% CI, 0.10-0.81; P = .01). Nonmechanical ventilation interventions tended to improve sleep quantity (SMD, 0.65; 95% CI, -0.03 to 1.33; P = .06) and to reduce sleep fragmentation (SMD, -0.29; 95% CI, -0.61 to 0.03; P = .07).Conclusions: The synthesized evidence suggests that both mechanical ventilation- and nonmechanical ventilation-based therapies improve sleep quantity and quality in critically ill patients, but the clinical significance is unclear. In the future, adequately powered multicenter RCTs involving pharmacologic interventions to promote sleep in critically ill patients are warranted. [ABSTRACT FROM AUTHOR]