Comparative Efficacy and Safety of Wakefulness-Promoting Agents for Excessive Daytime Sleepiness in Patients With Obstructive Sleep Apnea : A Systematic Review and Network Meta-analysis.

BACKGROUND: Excessive daytime sleepiness (EDS) is common among patients with obstructive sleep apnea (OSA). The comparative effectiveness of pharmacologic agents is unknown. PURPOSE: To compare the effectiveness of drugs for EDS in OSA using network meta-analysis. DATA SOURCES: MEDLINE, CENTRAL, EMBASE, and ClinicalTrials.gov to 7 November 2022. STUDY SELECTION: Reviewers identified randomized trials that enrolled patients with EDS-associated OSA on or eligible for conventional therapy assigned to any pharmacologic intervention. DATA EXTRACTION: Paired reviewers independently extracted data addressing effects of drugs on the Epworth Sleepiness Scale (ESS), Maintenance of Wakefulness Test (MWT), and adverse events at the longest reported follow-up. The certainty of evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. DATA SYNTHESIS: Fourteen trials (3085 patients) were eligible. At 4 weeks, compared with placebo, solriamfetol improves ESS scores (mean difference [MD], -3.85 [95% CI, -5.24 to -2.50]; high certainty), and armodafinil-modafinil (MD, -2.25 [CI, -2.85 to -1.64]; moderate certainty) and pitolisant-H3-autoreceptor blockers (MD, -2.78 [CI, -4.03 to -1.51]; moderate certainty) probably improve ESS scores. At 4 weeks, compared with placebo, solriamfetol (standardized mean difference [SMD], 0.9 [CI, 0.64 to 1.17]) and armodafinil-modafinil (SMD, 0.41 [CI, 0.27 to 0.55]) improve MWT (both high certainty), whereas pitolisant-H3-autoreceptor blockers probably do not (moderate certainty). At 4 weeks, armodafinil-modafinil probably increases the risk for discontinuation due to adverse events (relative risk [RR], 2.01 [CI, 1.14 to 3.51]; moderate certainty); solriamfetol may increase the risk for discontinuation due to adverse events (RR, 2.07 [CI, 0.67 to 6.25]; low certainty). Low certainty evidence suggests these interventions may not increase the risk for serious adverse events. LIMITATIONS: There is limited evidence on long term or effectiveness among patients nonadherent or with mixed adherence to conventional OSA therapies. CONCLUSION: Solriamfetol, armodafinil-modafinil, and pitolisant reduce daytime sleepiness for patients with OSA already on conventional therapy, with solriamfetol likely superior. Adverse events probably increase the risk for discontinuation of armodafinil-modafinil and may increase the risk for discontinuation with solriamfetol. PRIMARY FUNDING SOURCE: None.

Association of clinically significant obstructive sleep apnoea with risks of contracting COVID-19 and serious COVID-19 complications: a retrospective population-based study of health administrative data.

RATIONALE/OBJECTIVES: Despite plausible pathophysiological mechanisms, more research is needed to confirm the relationship between obstructive sleep apnoea (OSA) and the risk of COVID-19 infection or COVID-19-related serious complications. METHODS: We conducted a retrospective population-based cohort study using provincial health administrative data (Ontario, Canada). Adults with physician-diagnosed OSA who received positive airway pressure therapy in the 5 years prepandemic (OSA group) were propensity score matched by baseline characteristics to individuals in the general population at low risk of OSA (non-OSA group) using inverse probability of treatment weighting. Weighted HRs of (1) a positive COVID-19 test and (2) COVID-19-related emergency department (ED) visits, hospitalisations, intensive care unit (ICU) admissions and mortality, within 12 months of pandemic onset, were compared between groups. We also evaluated the impact of comorbid cardiometabolic or chronic airways disease. RESULTS: We identified and matched 324 029 individuals in the OSA group to 4 588 200 individuals in the non-OSA group. Compared with the non-OSA group, those in the OSA group were at a greater hazard of testing positive for COVID-19 (HR=1.17, 95% CI 1.13 to 1.21), having a COVID-19-related ED visit (HR=1.62, 95% CI 1.51 to 1.73), hospitalisation (HR=1.50, 95% CI 1.37 to 1.65) or ICU admission (HR=1.53, 95% CI 1.27 to 1.84). COVID-19-related 30-day mortality was not different (HR=0.98, 95% CI 0.82 to 1.16).We found that for the OSA group, comorbid airways disease but not cardiometabolic conditions increased the hazards of COVID-19-related outcomes, including mortality. CONCLUSION: In this large population-based study, we demonstrated that a recent diagnosis of OSA requiring treatment was associated with an increased hazard of testing positive for COVID-19 and serious COVID-19-related complications, particularly in those with co-existing chronic airways disease.

Can the complete blood count be used as a reliable screening tool for obstructive sleep apnea?

PURPOSE: Since hypoxia increases erythropoietin production and inflammation, the complete blood count (CBC) has been proposed as an inexpensive alternative for obstructive sleep apnea (OSA) screening. The objective of this study was to determine whether or not intermittent hypoxia and OSA severity, as measured by the mean oxygen saturation (SpO2) and apnea-hypopnea index (AHI), affect parameters measured by the CBC. METHODS: This retrospective study included a total of 941 surgical patients who had a pre-operative home sleep study. The pre-operative CBC was extracted from the electronic patient records. Patients were stratified according to their AHI scores, into mild (AHI ≥ 5 - < 15), moderate (AHI ≥ 15 - < 30), and severe (AHI ≥ 30) OSA groups. RESULTS: There were 244 patients without OSA, 294 with mild, 223 with moderate, and 180 with severe OSA. Our analysis showed that hemoglobin (P = 0.010), hematocrit (P = 0.027), and basophils (P = 0.006) showed significant changes among the different severities of OSA. For mean SpO2, there were negative associations with body mass index (r = - 0.287; P < 0.001), age (r = - 0.077; P = 0.021), hemoglobin (r = - 0.208; P < 0.001), hematocrit (r = - 0.220; P < 0.001), red blood cells (r = - 0.107; P = 0.001), mean corpuscular volume (MCV) (r = - 0.159; P < 0.001), mean corpuscular hemoglobin (r = - 0.142; P < 0.001), and basophils (r = - 0.091; P = 0.007). All analyzed parameters remained within normal clinical range. Multivariable regression identified hemoglobin, MCV, and basophils to be independent predictors of mean SpO2 and AHI. CONCLUSION: Hemoglobin, MCV, and basophils were independently associated with intermittent hypoxia defined by mean SpO2 and AHI. Adding CBC parameters to other screening tools for OSA may have additional value due to its association with changes in mean SpO2.

Predictive Performance of Oximetry to Detect Sleep Apnea in Patients Taking Opioids.

BACKGROUND: Long-term use of opioids for treatment of chronic pain is associated with significant risks including worsening unrecognized or untreated sleep apnea that may increase morbidity and mortality. Overnight oximetry has been validated for predicting sleep apnea in surgical and sleep clinic patients. The objective of the study was to assess the predictive accuracy of oxygen desaturation index (ODI 4%) from home overnight oximetry when compared to apnea hypopnea index (AHI) from polysomnography for predicting sleep apnea in patients taking opioids for chronic pain. METHODS: This was a planned post hoc analysis of a prospective cohort study conducted at 5 pain clinics. Patient characteristics and daily morphine milligram equivalent (MME) dose were recorded. All consented patients underwent home overnight oximetry (PULSOX-300i, Konica Minolta Sensing, Inc, Osaka, Japan) and in-laboratory polysomnography. The predictive performance of ODI 4% from oximetry was assessed against AHI from polysomnography. RESULTS: Among 332 consented patients, 181 with polysomnography and overnight oximetry data were analyzed. The mean age and body mass index of 181 patients were 52 ± 13 years and 29 ± 6 kg/m2, respectively, with 40% men. The area under the receiver operating curve for ODI to predict moderate-to-severe sleep apnea (AHI ≥15 events/h) and severe sleep apnea (AHI ≥30 events/h) was 0.82 (95% confidence interval [CI], 0.75-0.88) and 0.87 (95% CI, 0.80-0.94). ODI ≥5 events/h had a sensitivity of 85% (95% CI, 74-92) and specificity of 57% (95% CI, 52-61) to predict moderate-to-severe sleep apnea. ODI ≥15 events/h had a sensitivity of 71% (95% CI, 55-83) and specificity of 88% (95% CI, 84-91) to predict severe sleep apnea. CONCLUSIONS: Overnight home oximetry has a high predictive performance in predicting moderate-to-severe and severe sleep apnea in patients on opioids for chronic pain. It is a useful additional tool for health care providers for the screening of sleep apnea in this high-risk group.

Identification of Sleep Medicine and Anesthesia Core Topics for Anesthesia Residency: A Modified Delphi Technique Survey.

BACKGROUND: Sleep disorders affect up to 25% of the general population and are associated with increased risk of adverse perioperative events. The key sleep medicine topics that are most important for the practice of anesthesiology have not been well-defined. The objective of this study was to determine the high-priority sleep medicine topics that should be included in the education of anesthesia residents based on the insight of experts in the fields of anesthesia and sleep medicine. METHODS: We conducted a prospective cross-sectional survey of experts in the fields of sleep medicine and anesthesia based on the Delphi technique to establish consensus on the sleep medicine topics that should be incorporated into anesthesia residency curricula. Consensus for inclusion of a topic was defined as >80% of all experts selecting "agree" or "strongly agree" on a 5-point Likert scale. Responses to the survey questions were analyzed with descriptive statistical methods and presented as percentages or weighted mean values with standard deviations (SD) for Likert scale data. RESULTS: The topics that were found to have 100% agreement among experts were the influence of opioids and anesthetics on control of breathing and upper airway obstruction; potential interactions of wake-promoting/hypnotic medications with anesthetic agents; effects of sleep and anesthesia on upper airway patency; and anesthetic management of sleep apnea. Less than 80% agreement was found for topics on the anesthetic implications of other sleep disorders and future pathways in sleep medicine and anesthesia. CONCLUSIONS: We identify key topics of sleep medicine that can be included in the future design of anesthesia residency training curricula.

Airway Oscillometry Detects Spirometric-Silent Episodes of Acute Cellular Rejection.

Rationale: Acute cellular rejection (ACR) is common during the initial 3 months after lung transplant. Patients are monitored with spirometry and routine surveillance transbronchial biopsies. However, many centers monitor patients with spirometry only because of the risks and insensitivity of transbronchial biopsy for detecting ACR. Airway oscillometry is a lung function test that detects peripheral airway inhomogeneity with greater sensitivity than spirometry. Little is known about the role of oscillometry in patient monitoring after a transplant.Objectives: To characterize oscillometry measurements in biopsy-proven clinically significant (grade ≥2 ACR) in the first 3 months after a transplant.Methods: We enrolled 156 of the 209 double lung transplant recipients between December 2017 and March 2019. Weekly outpatient oscillometry and spirometry and surveillance biopsies at Weeks 6 and 12 were conducted at our center.Measurements and Main Results: Of the 138 patients followed for 3 or more months, 15 patients had 16 episodes of grade 2 ACR (AR2) and 44 patients had 64 episodes of grade 0 ACR (AR0) rejection associated with stable and/or improving spirometry. In 15/16 episodes of AR2, spirometry was stable or improving in the weeks leading to transbronchial biopsy. However, oscillometry was markedly abnormal and significantly different from AR0 (P < 0.05), particularly in integrated area of reactance and the resistance between 5 and 19 Hz, the indices of peripheral airway obstruction. By 2 weeks after biopsy, after treatment for AR2, oscillometry in the AR2 group improved and was similar to the AR0 group.Conclusions: Oscillometry identified physiological changes associated with AR2 that were not discernible by spirometry and is useful for graft monitoring after a lung transplant.

Morbidity and mortality reduction associated with polysomnography testing in idiopathic pulmonary fibrosis: a population-based cohort study.

BACKGROUND: It is not well-known if diagnosing and treating sleep breathing disorders among individuals with idiopathic pulmonary fibrosis (IPF) improves health outcomes. We evaluated the association between receipt of laboratory-based polysomnography (which is the first step in the diagnosis and treatment of sleep breathing disorders in Ontario, Canada) and respiratory-related hospitalization and all-cause mortality among individuals with IPF. METHODS: We used a retrospective, population-based, cohort study design, analyzing health administrative data from Ontario, Canada, from 2007 to 2019. Individuals with IPF were identified using an algorithm based on health administrative codes previously developed by IPF experts. Propensity score matching was used to account for potential differences in 41 relevant covariates between individuals that underwent polysomnography (exposed) and individuals that did not undergo polysomnography (controls), in order minimize potential confounding. Respiratory-related hospitalization and all-cause mortality were evaluated up to 12 months after the index date. RESULTS: Out of 5044 individuals with IPF identified, 201 (4.0%) received polysomnography, and 189 (94.0%) were matched to an equal number of controls. Compared to controls, exposed individuals had significantly reduced rates of respiratory-related hospitalization (hazard ratio [HR] 0.43, 95% confidence interval [CI] 0.24-0.75), p = 0.003) and all-cause mortality (HR 0.49, 95% CI 0.30-0.80), p = 0.004). Significantly reduced rate of respiratory-related hospitalization (but not all-cause mortality) was also observed among those with > = 1 respiratory-related hospitalization (HR 0.38, 95% CI 0.15-0.99) and systemic corticosteroid receipt (HR 0.37, 95% CI 0.19-0.94) in the year prior to the index date, which reflect sicker subgroups of persons. CONCLUSIONS: Undergoing polysomnography was associated with significantly improved clinically-important health outcomes among individuals with IPF, highlighting the potential importance of incorporating this testing in IPF disease management.

A review of respiratory manifestations and their management in Ehlers-Danlos syndromes and hypermobility spectrum disorders.

BACKGROUND: Ehlers-Danlos Syndromes (EDS) and Hypermobility Spectrum Disorders (HSD) are a heterogeneous group of heritable genetic connective tissue disorders with multiple characteristics including joint hypermobility, tissue fragility, and multiple organ dysfunction. Respiratory manifestations have been described in EDS patients, but have not been systematically characterized. A narrative review was undertaken to describe the respiratory presentations and management strategies of individuals with EDS and HSD. METHODS: A broad literature search of Medline, Embase, Cochrane Database of Systematic Reviews, and Cochrane CENTRAL was undertaken from inception to November 2020 of all study types, evaluating EDS/ HSD and pulmonary conditions. This narrative review was limited to adult patients and publications in English. RESULTS: Respiratory manifestations have generally been described in hypermobile EDS (hEDS), classical and vascular EDS subtypes. Depending on EDS subtype, they may include but are not limited to dyspnea, dysphonia, asthma, sleep apnea, and reduced respiratory muscle function, with hemothorax and pneumothorax often observed with vascular EDS. Respiratory manifestations in HSD have been less frequently characterized in the literature, but exertional dyspnea is the more common symptom described. Respiratory symptoms in EDS can have an adverse impact on quality of life. The respiratory management of EDS patients has followed standard approaches with thoracotomy tubes and pleurodesis for pleural manifestations, vocal cord strengthening exercises, continuous positive pressure support for sleep apnea, and exercise training. Reduced respiratory muscle function in hEDS patients responds to inspiratory muscle training. CONCLUSION: Respiratory symptoms and manifestations are described in EDS and HSD, and have generally been managed using conservative non-surgical strategies. Research into the prevalence, incidence and specific respiratory management strategies in EDS and HSD is needed to mitigate some of the associated morbidity.

Dissociation between objectively quantified snoring and sleep quality.

BACKGROUND: The impact of simple snoring on sleep structure and sleepiness has not been well described. In several studies, self-reported snoring was associated with increased daytime sleepiness. However, most studies did not distinguish patients with simple snoring from those with coexisting obstructive sleep apnea (OSA) using objective measures. We therefore evaluated the relationship between objectively measured snoring and both sleep structure and daytime sleepiness in patients with no or mild OSA. METHODS: Subjects referred for suspected sleep disorders underwent polysomnography (PSG) during which breath sounds were recorded by a microphone. Those with an apnea-hypopnea index (AHI) <15/h were analyzed. Individual snores were identified by a computer algorithm, from which the snore index (SI) was calculated as the number of snores/h of sleep. Sleep stages and arousals were quantified. Daytime sleepiness was evaluated using the Epworth Sleepiness Scale (ESS) score. RESULTS: 74 (35 males) subjects were included (age, mean ±â€¯SD: 46.4 ±â€¯15.3 years and body mass index: 29.8 ±â€¯7.0 kg/m2). The mean SI was 266 ±â€¯243 snores/h. Subjects were categorized according to their SI into 3 tertiles: SI < 100, between 100-350, and >350. No sleep structure indeces, arousals, or ESS score differed among SI tertiles (p > 0.13). There was no correlation between SI and any of these variables (p > 0.29). In contrast, the AHI was significantly related to frequency of arousals (r = 0.23, p = 0.048). CONCLUSIONS: These findings suggest that simple snoring assessed objectively is not related to indices of sleep structure or subjective sleepiness.

Risk of major cardiovascular and cerebrovascular complications after elective surgery in patients with sleep-disordered breathing: A retrospective cohort analysis.

BACKGROUND: There is limited and conflicting data on whether sleep-disordered breathing (SDB) is associated with postoperative major cardiovascular and cerebrovascular events (MACCE), and mortality. OBJECTIVES: To determine whether SDB is associated with increased risks of MACCE, mortality and length of hospital stay. DESIGN: Retrospective cohort analysis from the Nationwide Inpatient Sample. SETTING: Adults who underwent elective abdominal, orthopaedic, prostatic, gynaecological, thoracic, transplant, vascular or cardiac surgery in the United States of America between 2011 and 2014. PATIENTS: The study cohort included 1813 974 surgical patients, of whom 185 615 (10.2%) had SDB. Emergency or urgent surgical procedures were excluded. MAIN OUTCOME MEASURES: The incidences of MACCE, respiratory and vascular complications, in-hospital mortality and mean length of hospital stay were stratified by SDB. Linear and logistic regression models were constructed to determine the independent association between SDB and outcomes of interest. RESULTS: The incidences of MACCE [25.3 vs. 19.8%, odds ratio (OR) 1.20, P < 0.001] and respiratory complications (11.75 vs. 8.0%, OR 1.43, P < 0.001) were significantly higher in patients with SDB than in those without SDB. SDB was associated with higher rates of atrial fibrillation (14.7 vs. 10.8%, P < 0.001), other arrhythmias (6.0 vs. 5.4%, P < 0.001) and congestive heart failure (9.8 vs. 7.1%, P < 0.001). SDB patients had a lower rate of myocardial infarction (3.1 vs. 3.4%, OR 0.69, P < 0.001), lower mortality (0.6 vs. 1.3%, P < 0.001) and shorter length of hospital stay (4.8 vs. 5.2 days, P < 0.001). CONCLUSION: SDB was associated with increased risks of MACCE, and respiratory and vascular complications, but had a lower incidence of in-hospital mortality and shorter length of hospital stay.

Temporal shifts in fluid in pulmonary hypertension with and without sleep apnea.

Overnight extracellular rostral fluid shifts have been shown to be of importance in patients with fluid-retaining states and are associated with a higher prevalence of sleep apnea. Pulmonary hypertension is frequently associated with right ventricular dysfunction and progressive right ventricular failure, and an increased prevalence of sleep apnea has been described. In light of the importance of fluid shifts in the pathophysiology of sleep apnea, we aimed to explore temporal fluid shifts in patients with pulmonary hypertension with and without sleep apnea. Patients with pulmonary hypertension (WHO Group 1 or 4) had overnight extracellular rostral fluid shift assessment before and a minimum of 3 months after initiation of pulmonary hypertension-specific therapy. Fluid shift measurements of extracellular leg, abdominal, thoracic and neck fluid volumes were performed simultaneously. Twenty-nine patients with pulmonary hypertension (age 55 ± 16 years, 69% female) participated. Sleep apnea was diagnosed in 15 subjects (apnea-hypopnea index 14 [8-27] per hr). There were no significant differences in baseline or overnight leg extracellular rostral fluid, abdominal extracellular rostral fluid, thoracic extracellular rostral fluid or neck extracellular rostral fluid between those with and without sleep apnea. There was a significant inverse correlation between the sleep apnea severity and the overnight change in leg extracellular rostral fluid (r = -0.375, p = 0.049). There were no significant differences detected in overnight extracellular rostral fluid shifts from baseline to follow-up. Treatment-naïve patients with pulmonary hypertension both with and without sleep apnea demonstrate overnight extracellular rostral fluid shifts from the legs into the thorax and neck. Pulmonary hypertension-specific treatment, while significantly improving cardiac haemodynamics, had little impact on nocturnal extracellular rostral fluid shifts or the presence of sleep apnea.

The prevalence of obstructive sleep apnea in mild cognitive impairment: a systematic review.

BACKGROUND: Previous studies have shown that obstructive sleep apnea (OSA) is associated with a higher risk of cognitive impairment or dementia in the elderly, leading to deleterious health effects and decreasing quality of life. This systematic review aims to determine the prevalence of OSA in patients with mild cognitive impairment (MCI) and examine whether an association between OSA and MCI exists. METHODS: We searched Medline, PubMed, Embase, Cochrane Central, Cochrane Database of Systematic Reviews, PsychINFO, Scopus, the Web of Science, ClinicalTrials.gov and the International Clinical Trials Registry Platform for published and unpublished studies. We included studies in adults with a diagnosis of MCI that reported on the prevalence of OSA. Two independent reviewers performed the abstract and full-text screening, data extraction and the study quality critical appraisal. RESULTS: Five studies were included in the systematic review. Overall, OSA prevalence rates in patients with MCI varied between 11 and 71% and were influenced by OSA diagnostic methods and patient recruitment locations (community or clinic based). Among studies using the following OSA diagnostic measures- self-report, Home Sleep Apnea Testing, Berlin Questionnaire and polysomnography- the OSA prevalence rates in MCI were 11, 27, 59 and 71%, respectively. In a community-based sample, the prevalence of OSA in patients with and without MCI was 27 and 26%, respectively. CONCLUSIONS: Based on limited evidence, the prevalence of OSA in patients with MCI is 27% and varies based upon OSA diagnostic methods and patient recruitment locations. Our findings provide an important framework for future studies to prospectively investigate the association between OSA and MCI among larger community-based cohorts and implement a standardized approach to diagnose OSA in memory clinics. PROSPERO REGISTRATION: CRD42018096577.

Short- and long-term continuous positive airway pressure usage in the post-stroke population with obstructive sleep apnea.

PURPOSE: Obstructive sleep apnea (OSA) is highly prevalent in post-stroke patients and observational evidence suggests that untreated it is a harbinger of poorer outcomes in this population. Clinical trials on the impact of treatment of OSA with continuous positive airway pressure (CPAP) have countered difficulties with patient engagement and adherence to CPAP therapy. Real-world data on continuous positive airway pressure initiation and usage in the post-stroke population with obstructive sleep apnea is limited. METHODS: We performed a clinical retrospective study between January 2006 and June 2015 to describe the short- and long-term CPAP usage in the post-stroke population with OSA, and to assess which patient, disease, and treatment-related factors were associated with CPAP purchase, initiation, and usage in this population. RESULTS: Of 191 post-stroke patients' recommended CPAP therapy, post-prescription usage at 3, 6, 12, 24, and 60 months was 58%, 53%, 48%, 45%, and 39% respectively. OSA severity-related factors, such as AHI or degree of nocturnal hypoxemia, were not significantly associated with CPAP usage. Predictors of CPAP usage at all time points were younger age, male sex, never smokers, and no history of hypertension. There were some differences in predictors of CPAP usage between early and later time periods. CONCLUSIONS: We demonstrated that the long-term usage of CPAP therapy is possible with most of the attrition occurring in the first 3 months. Upfront healthcare resource allocation to CPAP initiation and usage in this population may improve longer-term usage.

Evaluation of Cerebrovascular Reactivity in Subjects with and without Obstructive Sleep Apnea.

BACKGROUND: Both obstructive sleep apnea (OSA) and altered cerebrovascular reactivity (CVR) are associated with increased stroke risk. Nevertheless, the incidence of abnormal CVR in patients with OSA is uncertain due to the high variability in the way CVR is measured both within and between studies. We hypothesized that a standardized CVR with a consistent vasoactive stimulus and cerebral blood flow (CBF) measure would be reduced in patients with severe OSA compared with healthy controls. METHODS: This was a prospective study in which subjects with and without OSA were administered a standardized hypercapnic stimulus, and CBF was monitored by blood oxygen level-dependent magnetic resonance signal changes, a high space and time resolved surrogate for CBF. RESULTS: Twenty-four subjects with OSA (mean age 45.9 years, apnea-hypopnea index [AHI] 26.8 per hour) and 6 control subjects (mean age 42.8 years, AHI 2.4 per hour) were included. Compared with controls, subjects with OSA had a significantly greater whole brain (.1565 versus .1094, P = .013), gray matter (.2077 versus .1423, P = .009), and white matter (.1109 versus .0768, P = .024) CVR, respectively. CONCLUSIONS: Contrary to expectations, subjects with OSA had greater CVR compared with control subjects.

In-hospital diagnosis of sleep apnea in stroke patients using a portable acoustic device.

PURPOSE: Sleep apnea (SA) is highly prevalent in post-stroke patients. Due to physical disability and relative inaccessibility of polysomnography (PSG) to test for SA, patients with stroke frequently remain undiagnosed and untreated. Portable SA monitoring can facilitate at-home or in-hospital testing for SA. However, portable SA monitoring is not recommended in those with complex medical conditions, such as stroke, due to the lack of validation of portable monitoring in such patients. METHODS: The objective of our study was to test the accuracy and feasibility of a portable single-channel acoustic device, BresoDx™ for quantifying the apnea-hypopnea index (AHI) and diagnosing SA in a post-stroke population. Patients who recently suffered a stroke and were undergoing rehabilitation in a stroke rehabilitation unit (SRU) underwent testing with BresoDx both simultaneously during attended PSG and unattended on the SRU. RESULTS: We studied 23 stroke patients of whom 78% had SA (defined by AHI ≥15) on PSG. All of the patients tolerated the BresoDx. Using cutoff AHI of ≥15 by PSG to diagnose SA, BresoDx had sensitivity of 90.0%, specificity of 84.6%, and overall accuracy of 87.0% in the laboratory. CONCLUSIONS: This study demonstrates that BresoDx is well tolerated and feasible to use in the post-stroke population where it was found to have excellent positive and negative predictive values for the diagnosis of SA.

Significance of obstructive sleep apnea in the patient with pulmonary hypertension.

PURPOSE OF REVIEW: The purpose of this review was to evaluate the consequence of obstructive sleep apnea (OSA) in pulmonary hypertension by reviewing the current literature and understanding potential pathophysiological mechanisms. RECENT FINDINGS: Small studies have suggested a high prevalence of comorbid OSA in those with known pulmonary hypertension. Pathophysiological mechanisms are highly suggestive of potential deleterious effect of OSA on pulmonary hemodynamics. SUMMARY: Clearly, current research work on comorbid OSA and pulmonary hypertension is still in its infancy and the field is ripe for future investigation. The significance of OSA in this population has yet to be fully determined.

Sleep breathing disorder frequency, risk factors, and treatment among adults with cystic fibrosis.

BACKGROUND: Our understanding of the epidemiology of sleep breathing disorders among adults with cystic fibrosis (CF) is limited. Our purpose was to describe the frequency, risk factors and treatment of sleep breathing disorders among adults with CF. METHODS: This was a retrospective analysis of linked data from laboratory-based diagnostic polysomnography (PSG) undertaken at St. Michael's Hospital (Toronto, Canada) and the Canadian CF Registry. Adults (≥19 years old) with CF that underwent a diagnostic PSG at St. Michael's Hospital between 2002 and 2021 were included. Sleep breathing disorder frequency, risk factors, and treatment were described, using descriptive statistics and logistic regression. RESULTS: There were 42 patients included (33.3 % women and median age at diagnostic PSG was 34.7 years). Obstructive sleep apnea [OSA] was the most commonly observed sleep breathing disorder (found in 64.3 %), followed by sustained nocturnal hypoxemia (16.7 %), and sleep hypoventilation (9.5 %). Only 41 % of individuals with an elevated total apnea-hypopnea index were receiving positive airway pressure [PAP] therapy. Corticosteroid use (either oral or inhaled) was the only factor with a significant positive association with presence of any sleep breathing disorder (odds ratio 5.00, 95 % confidence interval 1.28-22.78). CONCLUSIONS: Among adults with CF, OSA occurs more commonly than previously appreciated and the majority of sleep breathing disorders were not being treated with PAP or supplemental oxygen. Management of sleep breathing disorders among adults with CF reflects a potentially important care gap, but further research is needed to determine the health impacts of treating sleep breathing disorders in CF.

Office-based respiratory assessment in patients with generalized myasthenia gravis.

Patients with myasthenia gravis (MG) can present with respiratory dysfunction, ranging from exercise intolerance to overt respiratory failure, increased fatigue, or sleep-disordered breathing. To investigate the value of multiple respiratory tests in MG, we performed clinical and respiratory assessments in patients with mild to moderate generalized disease. One-hundred and thirty-six patients completed the myasthenia gravis quality-of-life score(MG-QOL-15), myasthenia gravis impairment index(MGII), Epworth sleepiness scale(ESS), University of California-San Diego Shortness of Breath Questionnaire(UCSD-SOB), Modified Medical Research Council Dyspnea Scales(MRC-DS), supine and upright forced vital capacity(FVC), maximal inspiratory pressures(MIPs) and sniff nasal inspiratory pressures(SNIP). Seventy-three (54 %) had respiratory and/or bulbar symptoms and 45 (33 %) had baseline abnormal FVC, with no significant postural changes (p = 0.89); 55 (40.4 %) had abnormal MIPs and 50 (37 %) had abnormal SNIPs. Overall, there were low scores on respiratory and disability scales. Females had increased odds of presenting with abnormal FVC (OR 2.89, p = 0.01) and MIPs (OR 2.48, p = 0.022). There were significant correlations between MIPs, FVC and SNIPs; between MGII/MG-QOL15 and UCSD-SOB/MRC-DS and between ESS and respiratory scales in the whole group. Our data suggests that office-based respiratory measurements are a useful screening method for stable MG patients, even when presenting with minimal respiratory symptoms and no significant disability.