The impact of different CPAP delivery approaches on nightly adherence and discontinuation rate in patients with obstructive sleep apnea.

Study Objectives: The impact of direct mail order sales of positive airway pressure (PAP) devices, accentuated by the coronavirus disease 2019 (COVID-19) pandemic, on PAP adherence in patients with obstructive sleep apnea remains unclear. In this study we compared the impact of different modes of continuous positive airway pressure delivery on adherence and daytime symptoms. We hypothesized that adherence would not be affected by remote PAP setup, aided by telehealth technology.

Clinical Use of Loop Gain Measures to Determine Continuous Positive Airway Pressure Efficacy in Patients with Complex Sleep Apnea. A Pilot Study.

Rationale: Measures of unstable ventilatory control (loop gain) can be obtained directly from the periodic breathing duty ratio on polysomnography in patients with Cheyne-Stokes respiration/central sleep apnea and can predict the efficacy of continuous positive airway pressure (CPAP) therapy.

Objectives: In this pilot study, we aimed to determine if this measure could also be applied to patients with complex sleep apnea (predominant obstructive sleep apnea, with worsening or emergent central apneas on CPAP). We hypothesized that loop gain was higher in patients whose central events persisted 1 month later despite CPAP treatment versus those whose events resolved over time.

Impact of CPAP use and age on mortality in patients with combined COPD and obstructive sleep apnea: the overlap syndrome.

Background: The overlap syndrome, defined by concurrent existence of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA), is associated with poor outcomes. From a large outpatient cohort we aimed to define better the risk factors for increased mortality in the overlap syndrome and hypothesized that CPAP adherence would be associated with improved survival in patients with overlap syndrome.

Methods: A post hoc analysis from an outpatient database of 10,272 patients from 2007-2010, identified 3,396 patients which were classified in 6 groups; patients both alive or deceased, with the known diagnosis of COPD, OSA, and the overlap of COPD plus OSA.

Circulating endothelial cells and endothelial progenitor cells in obstructive sleep apnea.

Increased circulating endothelial cells (CECs) have been observed in patients with vascular injury associated with acute myocardial infarction, pulmonary hypertension, and congestive heart failure. Decreased circulating endothelial progenitor cells (EPCs) have been observed in patients with risk factors for cardiovascular disease. Obstructive sleep apnea (OSA) is associated with increased risk of cardiovascular disease and endothelial dysfunction.

How early in treatment is PAP adherence established? Revisiting night-to-night variability.

Obstructive sleep apnea (OSA) is a serious disorder with significant daytime consequences. Treatment for OSA most commonly takes the form of positive airway pressure (PAP). Although effective, PAP adherence is often below expectations.

The impact of cardiac resynchronization therapy on obstructive sleep apnea in heart failure patients: a pilot study.

Background: Cardiac resynchronization therapy (CRT) has been shown to improve cardiac function and reduce Cheyne-Stokes respiration but has not been evaluated in patients with obstructive sleep apnea (OSA). In this pilot study, we investigated the impact of both CRT and CRT plus increased rate pacing in heart failure (ie, congestive heart failure [CHF]) patients with OSA. We hypothesized that through increased cardiac output CRT/pacing would reduce obstructive events and daytime symptoms of sleepiness.

Brief behavioral therapies reduce early positive airway pressure discontinuation rates in sleep apnea syndrome: preliminary findings.

Sleep apnea syndrome (SAS) is a serious disorder with significant daytime consequences. Treatment for SAS most commonly takes the form of positive airway pressure (PAP). Although effective, PAP adherence is often below expectations.

Normalization of memory performance and positive airway pressure adherence in memory-impaired patients with obstructive sleep apnea.

Background: Although the treatment of obstructive sleep apnea (OSA) with positive airway pressure (PAP) has been shown to be effective, nightly adherence to treatment remains poor. The objective of this study was to examine the degree to which various levels of PAP therapy adherence normalized verbal memory function after 3 months of therapy in patients with OSA who were memory-impaired prior to the initiation of PAP therapy.

Methods: Participants were administered neuropsychological testing prior to the initiation of PAP treatment and at a 3-month follow-up visit.

The influence of white noise on sleep in subjects exposed to ICU noise.

Background And Purpose: There is disagreement in the literature about the importance of sleep disruption from intensive care unit (ICU) environmental noise. Previous reports have assumed that sleep disruption is produced by high-peak noise. This study aimed to determine whether peak noise or the change in noise level from baseline is more important in inducing sleep disruption.

Vasoactive drug use in septic shock.

Sepsis accounts for more than 210,000 deaths per year. Despite adequate fluid resuscitation the associated maldistribution of blood flow may cause an imbalance between oxygen delivery and demand, leading to global tissue hypoxia, shock, and, if not reversed, death. Vasoactive therapies including catecholamine and noncatecholamine vasopressors, ionotropes, and vasodilating agents aimed at restoring perfusion and normalizing oxygen consumption have improved outcomes in patients with persistent shock despite crystalloid resuscitation.

Treatment adherence and outcomes in flexible vs standard continuous positive airway pressure therapy.

Study Objectives: To compare adherence and clinical outcomes between flexible positive airway pressure (PAP) [C-Flex; Respironics; Murraysville, PA] and standard PAP therapy (ie, continuous positive airway pressure [CPAP]).

Design And Setting: A controlled clinical trial of CPAP therapy vs therapy using the C-Flex device in participants with moderate-to-severe obstructive sleep apnea. Participants were recruited from and followed up through an academic sleep disorders center.

Lung volume and continuous positive airway pressure requirements in obstructive sleep apnea.

Previous studies have demonstrated that lung volume during wakefulness influences upper airway size and resistance, particularly in patients with sleep apnea. We sought to determine the influence of lung volume on the level of continuous positive airway pressure (CPAP) required to prevent flow limitation during non-REM sleep in subjects with sleep apnea. Seventeen subjects (apnea-hypopnea index, 42.

Examining the construct of depression in obstructive sleep apnea syndrome.

Background And Purpose: Depression is commonly reported by patients suffering from Obstructive Sleep Apnea Hypopnea Syndrome (OSAS). We used the factor structure of the Beck Depression Inventory-2nd edition (BDI-II) to examine the unique contributions of OSAS severity and obesity to depressive symptoms in OSAS. We predicted that the Somatic and Cognitive dimensions of the BDI-II would be more strongly associated with apnea severity and obesity, respectively.

Postural effects on pharyngeal protective reflex mechanisms.

Study Objectives: Pharyngeal muscle dilators are important in obstructive sleep apnea pathogenesis because the failure of protective reflexes involving these muscles yields pharyngeal collapse. Conflicting results exist in the literature regarding the responsiveness of these muscles during stable non-rapid eye movement sleep. However, variations in posture in previous studies may have influenced these findings.

The influence of lung volume on pharyngeal mechanics, collapsibility, and genioglossus muscle activation during sleep.

Study Objectives: Previous studies in both awake and sleeping humans have demonstrated that lung-volume changes substantially affect upper-airway size and pharyngeal resistance and, thus, may influence pharyngeal patency. We sought to systematically investigate the isolated effects of lung-volume changes on pharyngeal collapsibility and mechanics and genioglossus muscle activation during stable non-rapid eye movement sleep. We hypothesized that lower lung volumes would lead to increased pharyngeal collapsibility, airflow resistance, and, in compensation, augmented genioglossus muscle activation.

Within-breath control of genioglossal muscle activation in humans: effect of sleep-wake state.

Pharyngeal dilator muscles are clearly important in the pathogenesis of obstructive sleep apnoea syndrome. Substantial data support the role of a local negative pressure reflex in modifying genioglossal activation across inspiration during wakefulness. Using a model of passive negative pressure ventilation, we have previously reported a tight relationship between varying intrapharyngeal negative pressures and genioglossal muscle activation (GGEMG) during wakefulness.

Continuous positive airway pressure therapy for treating sleepiness in a diverse population with obstructive sleep apnea: results of a meta-analysis.

Background: Although continuous positive airway pressure (CPAP) has become the standard of care in the treatment of obstructive sleep apnea (OSA), 2 systematic reviews have questioned its utility. Since the publication of these reviews, several randomized controlled trials have been reported. We, therefore, performed a meta-analysis to assess the effect of CPAP on subjective and objective sleepiness.

Awake negative pressure reflex response of the genioglossus in OSA patients and normal subjects.

We hypothesized that the response of the genioglossus to negative pressure during wakefulness should be intact in obstructive sleep apnea (OSA) patients despite published evidence showing impairment of the response of palatal muscles (Mortimore IL and Douglas NJ. Am J Respir Crit Care Med 156: 867-873, 1997). Thus the response of the genioglossus to brief nasal negative pressure applications (NPAs) in early inspiration was compared between OSA patients and an age-matched group of normal subjects at two study sites (n = 11 per group in Long Beach, n = 14 per group in Boston).

Genioglossus muscle responsiveness to chemical and mechanical stimuli during non-rapid eye movement sleep.

Previous studies have suggested that during non-rapid eye movement (NREM) sleep, neither large short-duration resistive loads nor sustained normoxic hypercapnia alone leads to increased genioglossus muscle activation. However, in normal individuals during stable NREM sleep, genioglossus activity rises above baseline as PCO2 rises and airway resistance increases. We therefore hypothesized that combinations of chemical (PCO2, PO2) and mechanical stimuli during NREM sleep would lead to increased genioglossal activation.

Association of lung perfusion disparity and mortality in patients with cystic fibrosis awaiting lung transplantation.

Background: The risk of death for patients with end-stage cystic fibrosis awaiting lung transplantation remains high and most patients succumb to respiratory failure. This study was conducted to evaluate the usefulness of ventilation-perfusion scintillation scans, obtained during the pre-transplant period, to identify patterns that predict prognosis while on the waiting list. These patterns were compared with other pulmonary physiologic markers of ventilation and perfusion obtained from pulmonary function and cardiopulmonary exercise tests.