Identification of sleep phenotypes in COPD using machine learning-based cluster analysis.

BACKGROUND: Disturbed sleep in patients with COPD impact quality of life and predict adverse outcomes. RESEARCH QUESTION: To identify distinct phenotypic clusters of patients with COPD using objective sleep parameters and evaluate the associations between clusters and all-cause mortality to inform risk stratification. STUDY DESIGN AND METHODS: A longitudinal observational cohort study using nationwide Veterans Health Administration data of patients with COPD investigated for sleep disorders. Sleep parameters were extracted from polysomnography physician interpretation using a validated natural language processing algorithm. We performed cluster analysis using an unsupervised machine learning algorithm (K-means) and examined the association between clusters and mortality using Cox regression analysis, adjusted for potential confounders, and visualized with Kaplan-Meier estimates. RESULTS: Among 9992 patients with COPD and a clinically indicated baseline polysomnogram, we identified five distinct clusters based on age, comorbidity burden and sleep parameters. Overall mortality increased from 9.4 % to 42 % and short-term mortality (<5.3 years) ranged from 3.4 % to 24.3 % in Cluster 1 to 5. In Cluster 1 younger age, in 5 high comorbidity burden and in the other three clusters, total sleep time and sleep efficiency had significant associations with mortality. INTERPRETATION: We identified five distinct clinical clusters and highlighted the significant association between total sleep time and sleep efficiency on mortality. The identified clusters highlight the importance of objective sleep parameters in determining mortality risk and phenotypic characterization in this population.

Rates and Predictors of Rapid Eye Movement Sleep Behavior Disorder Symptoms Among Post-9/11 Veterans.

OBJECTIVE: Posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI), which are prevalent conditions among post-9/11 veterans, increase risks of rapid eye movement (REM) sleep behavior disorder (RBD) and degenerative synucleinopathy. Rates and predictors of RBD symptoms were investigated by screening post-9/11 veterans for RBD with a validated questionnaire. METHODS: In this cross-sectional analysis, consecutive patients in the Houston Translational Research Center for TBI and Stress Disorders (TRACTS) were screened with the English translation of the RBD Questionnaire-Hong Kong (RBDQ-HK). In addition to data from the standard TRACTS battery, systematic chart review was used to identify known sleep disorders mimicking or manifesting RBD. RESULTS: Of the 119 patients with available RBDQ-HK scores, 71 (60%) and 65 (55%) screened positive for RBD, when a total score ≥21 and a factor 2 score ≥8 were used as cutoff scores, respectively. Univariable analyses with both cutoffs showed consistent associations between a positive RBDQ-HK screen and global sleep quality, number of TBI exposures, and PTSD severity. Multivariable logistic regression with total score ≥21 as a cutoff indicated that PTSD severity (odds ratio=1.06, 95% CI=1.02-1.10) and number of TBIs (odds ratio=1.63, 95% CI=1.16-2.41) were independent predictors of a positive screen, whereas global sleep quality was no longer significant. Multivariable logistic regression with factor 2 score ≥8 as a cutoff showed similar results. CONCLUSIONS: Interdisciplinary parasomnia assessment, further validation of RBD screens, and standardized reporting of REM sleep without atonia could provide necessary information on the pathophysiological relationships linking PTSD, TBI, RBD symptoms, and ultimately synucleinopathy risk among post-9/11 veterans.

Obesity paradox or hypoxia preconditioning: How obstructive sleep apnea modifies the Obesity-MI relationship.

OBJECTIVES: The objective of this study was to evaluate the interaction between obesity and obstructive sleep apnea on acute MI in hospital mortality. METHODS: This retrospective cohort study utilized Veterans Health Administration data from years 1999-2020. Participants were categorized according to their body mass index (BMI) to non-obese (BMI <30) and obese (BMI ≥30) groups. Clinical obstructive sleep apnea (SA) diagnosis was confirmed using ICD9/10 codes and the study subgroups included non-obese with no obstructive sleep apnea (nOB-nSA), non-Obese with obstructive sleep apnea (nOB-SA), obese with no obstructive sleep apnea (OB-nSA), and obese with obstructive sleep apnea (OB-SA). The primary outcome was odds ratio of in-hospital mortality during the hospitalization with acute MI as the principal diagnosis adjusted for age, gender, race, ethnicity, and Charlson comorbidity index (CCI) with the nOB-nSA group as the comparison group. RESULTS: Among 72,036 veterans with acute-MI hospitalization, individuals with obesity and obstructive sleep apnea (OB-SA) had the lowest in-hospital mortality rate (1.0%) compared to those without obesity and obstructive sleep apnea (nOB-nSA, 2.8%), with obesity but without obstructive sleep apnea (OB-nSA, 2.4%), and with obesity and obstructive sleep apnea (nOB-SA, 1.4%). The adjusted odds ratio for mortality, compared to nOB-nSA, was 9% higher but not significant in OB-nSA (aOR, 1.09, 95%CI: 0.95, 1.25), 46% lower in OB-nSA (aOR, 0.54, 95%CI: 0.45, 0.66), and 52% lower in OB-SA (aOR, 0.48: 95%CI: 0.41, 0.57). CONCLUSION: Our data suggest that the association between obesity and improved survival in acute MI is largely driven by the presence of sleep apnea.

Obstructive sleep apnea modulates clinical outcomes post-acute myocardial infarction: A large longitudinal veterans' dataset report.

BACKGROUND: While the longer-term Obstructive Sleep apnea (OSA)-related intermittent hypoxia (IH) leads to various comorbidities, it has become increasingly evident that OSA confers protective advantages during and after acute myocardial infarction (AMI). We hypothesized in patients who were admitted with acute MI, the presence of OSA is associated with lower in-hospital mortality compared to those without a prior diagnosis of OSA. METHODS: In this nationwide retrospective study utilizing Veterans Health Administration records, we included patients hospitalized for MI with a history of sleep disorders from 1999 to 2020. We divided patients into two cohorts: those with OSA and those without OSA. The primary outcome was in-hospital mortality during AMI hospitalization. We analyzed the data using logistic regression and calculated the odds ratio of in-hospital mortality. RESULTS: Out of more than four million veterans with any sleep diagnosis, 76,359 patients were hospitalized with a diagnosis of AMI. We observed 30,116 with OSA (age, 64 ± 10 years; BMI, 33 ± 7 kg/m2) and 43,480 without OSA (age, 68 ± 12 years; BMI, 29 ± 6 kg/m2). The aOR of in-patient mortality (n = 333 (1.1%)) was lower in those with OSA (aOR, 0.43; 95% CI, 0.38 to 0.49) compared to without-OSA (n = 1,102, 2.5%). However, the OSA cohort had a higher proportion of the prolonged length of stay (28.1%). CONCLUSIONS: Presence of OSA is associated with lower in-hospital mortality among patients admitted for AMI, after adjusting for various demographic and co-morbidity factors. This study highlights the complex relationship between OSA and cardiovascular health and highlights the need for further research in this area.

Mortality Patterns Associated with Central Sleep Apnea among Veterans: A Large, Retrospective, Longitudinal Report.

Rationale: Central sleep apnea (CSA) is associated with high mortality. Current knowledge stems from studies with limited sample size (fewer than 100 subjects) and in homogeneous populations such as heart failure (HF). Objectives: To address this knowledge gap, we compared the mortality pattern and time to death between the CSA and obstructive sleep apnea (OSA) patients in the large Veterans Health Administration patient population using the big data analytic approach. Methods: This is a retrospective study using national Veterans Health Administration electronic medical records from October 1, 1999, through September 30, 2020. We grouped the patients with underlying sleep disorders into CSA and OSA, using the International Classification of Diseases, Ninth and Tenth Revision codes. We applied Cox regression analysis to compare the mortality rate and hazard ratio (HR) among the two groups and adjusted HR by gender, race, body mass index (BMI), age, and Charlson Comorbidity Index. In CSA groups, a machine-learning algorithm was used to determine the most important predictor of time to death. Further subgroup analysis was also performed in patients that had comorbid HF. Results: Evaluation of patients resulted in 2,961 grouped as CSA and 1,487,353 grouped as OSA. Patients with CSA were older (61.8 ± 15.6 yr) than those with OSA (56.7 ± 13.9 yr). A higher proportion of patients with CSA (25.1%) died during the study period compared with the OSA cohort (14.9%). The adjusted HR was 1.53 (95% confidence interval [CI], 1.43-4.65). Presence of HF history of cerebrovascular disease, hemiplegia, and having a BMI less than 18.5 were among the highest predictors of mortality in CSA. The subgroup analysis revealed that the presence of HF was associated with increased mortality both in CSA (HR, 7.4; 95% CI, 6.67-8.21) and OSA (HR, 4.3; 95% CI, 4.26-4.34) groups. Conclusions: Clinically diagnosed CSA was associated with a shorter time to death from the index diagnostic date. Almost one-fifth of patients with CSA died within 5 years of diagnosis. The presence of HF, history of cerebrovascular disease and hemiplegia, male sex, and being underweight were among the highest predictors of mortality in CSA. CSA was associated with higher mortality than OSA, independent of associated comorbidity.

Prone Positioning for Acute Hypoxemic Respiratory Failure and ARDS: A Review.

Prone positioning is an immediately accessible, readily implementable intervention that was proposed initially as a method for improvement in gas exchange > 50 years ago. Initially implemented clinically as an empiric therapy for refractory hypoxemia, multiple clinical trials were performed on the use of prone positioning in various respiratory conditions, cumulating in the landmark Proning Severe ARDS Patients trial, which demonstrated mortality benefit in patients with severe ARDS. After this trial and the corresponding meta-analysis, expert consensus and societal guidelines recommended the use of prone positioning for the management of severe ARDS. The ongoing COVID-19 pandemic has brought prone positioning to the forefront of medicine, including widespread implementation of prone positioning in awake, spontaneously breathing, nonintubated patients with acute hypoxemic respiratory failure. Multiple clinical trials now have been performed to investigate the safety and effectiveness of prone positioning in these patients and have enhanced our understanding of the effects of the prone position in respiratory failure. In this review, we discuss the physiologic features, clinical outcome data, practical considerations, and lingering questions of prone positioning.

Sentiment Analysis of Insomnia-Related Tweets via a Combination of Transformers Using Dempster-Shafer Theory: Pre- and Peri-COVID-19 Pandemic Retrospective Study.

BACKGROUND: The COVID-19 pandemic has imposed additional stress on population health that may result in a change of sleeping behavior. OBJECTIVE: In this study, we hypothesized that using natural language processing to explore social media would help with assessing the mental health conditions of people experiencing insomnia after the outbreak of COVID-19. METHODS: We designed a retrospective study that used public social media content from Twitter. We categorized insomnia-related tweets based on time, using the following two intervals: the prepandemic (January 1, 2019, to January 1, 2020) and peripandemic (January 1, 2020, to January 1, 2021) intervals. We performed a sentiment analysis by using pretrained transformers in conjunction with Dempster-Shafer theory (DST) to classify the polarity of emotions as positive, negative, and neutral. We validated the proposed pipeline on 300 annotated tweets. Additionally, we performed a temporal analysis to examine the effect of time on Twitter users' insomnia experiences, using logistic regression. RESULTS: We extracted 305,321 tweets containing the word insomnia (prepandemic tweets: n=139,561; peripandemic tweets: n=165,760). The best combination of pretrained transformers (combined via DST) yielded 84% accuracy. By using this pipeline, we found that the odds of posting negative tweets (odds ratio [OR] 1.39, 95% CI 1.37-1.41; P<.001) were higher in the peripandemic interval compared to those in the prepandemic interval. The likelihood of posting negative tweets after midnight was 21% higher than that before midnight (OR 1.21, 95% CI 1.19-1.23; P<.001). In the prepandemic interval, while the odds of posting negative tweets were 2% higher after midnight compared to those before midnight (OR 1.02, 95% CI 1.00-1.07; P=.008), they were 43% higher (OR 1.43, 95% CI 1.40-1.46; P<.001) in the peripandemic interval. CONCLUSIONS: The proposed novel sentiment analysis pipeline, which combines pretrained transformers via DST, is capable of classifying the emotions and sentiments of insomnia-related tweets. Twitter users shared more negative tweets about insomnia in the peripandemic interval than in the prepandemic interval. Future studies using a natural language processing framework could assess tweets about other types of psychological distress, habit changes, weight gain resulting from inactivity, and the effect of viral infection on sleep.

Validation of a Natural Language Processing Algorithm for the Extraction of the Sleep Parameters from the Polysomnography Reports.

Background: There is a need to better understand the association between sleep and chronic diseases. In this study we developed a natural language processing (NLP) algorithm to mine polysomnography (PSG) free-text notes from electronic medical records (EMR) and evaluated the performance. Methods: Using the Veterans Health Administration EMR, we identified 46,093 PSG studies using CPT code 95,810 from 1 October 2000−30 September 2019. We randomly selected 200 notes to compare the accuracy of the NLP algorithm in mining sleep parameters including total sleep time (TST), sleep efficiency (SE) and sleep onset latency (SOL), wake after sleep onset (WASO), and apnea-hypopnea index (AHI) compared to visual inspection by raters masked to the NLP output. Results: The NLP performance on the training phase was >0.90 for precision, recall, and F-1 score for TST, SOL, SE, WASO, and AHI. The NLP performance on the test phase was >0.90 for precision, recall, and F-1 score for TST, SOL, SE, WASO, and AHI. Conclusions: This study showed that NLP is an accurate technique to extract sleep parameters from PSG reports in the EMR. Thus, NLP can serve as an effective tool in large health care systems to evaluate and improve patient care.

Smartphone-Guided Self-prone Positioning vs Usual Care in Nonintubated Hospital Ward Patients With COVID-19: A Pragmatic Randomized Clinical Trial.

BACKGROUND: Safe, effective, and easily implementable treatments that reduce the progression of respiratory failure in COVID-19 are urgently needed. Despite the increased adoption of prone positioning during the pandemic, the effectiveness of this technique on progression of respiratory failure among nonintubated patients is unclear. RESEARCH QUESTION: What is the effectiveness of smartphone-guided self-prone positioning recommendations and instructions compared with usual care in reducing progression of respiratory failure among nonintubated patients with COVID-19? STUDY DESIGN AND METHODS: Awake Prone Position for Early Hypoxemia in COVID-19 (APPEX-19) is a multicenter randomized clinical trial that randomized nonintubated adults with COVID-19 on < 6 L/min of supplemental oxygen to receive a smartphone-guided self-prone positioning intervention or usual care. The primary outcome was the composite of respiratory deterioration (an increase in supplemental oxygen requirement) or ICU transfer. Using a Bayesian statistical approach, the posterior probability of superiority within each treatment arm (superiority threshold 95%) was calculated. RESULTS: The trial was stopped early for slow enrollment. A total of 293 participants were included in the modified intention-to-treat analysis (159 self-prone positioning intervention and 134 usual care). Among participants who self-reported body positioning (n = 139 [70 intervention, 69 usual care]), 71.4% in the intervention arm and 59.4% in the usual care arm attempted prone positioning. Thirty-one participants (posterior mean, 24.7%; 95% credible interval, 18.6-31.4) receiving usual care and 32 participants (posterior mean, 22.1%; 95% credible interval, 16.6-28.1) receiving the self-prone positioning intervention experienced the primary outcome; the posterior probability of superiority for the self-prone positioning intervention was 72.1%, less than the 95% threshold for superiority. Adverse events occurred in 26.9% of participants in the usual care arm and in 11.9% of participants in the intervention arm. INTERPRETATION: Among nonintubated patients with COVID-19, smartphone-guided self-prone positioning recommendations and instructions did not promote strong adherence to prone positioning. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT04344587; URL: www. CLINICALTRIALS: gov.

Obstructive sleep apnea in diabetic patients is associated with higher healthcare utilization.

BACKGROUND: Obstructive sleep apnea (OSA) is a frequent comorbid condition in patients with type 2 diabetic (T2DM). Concomitant OSA is associated with a detrimental impact on metabolic control. Both OSA and T2DM independently lead to increased cardiovascular disease and mortality. The impact of OSA on the acceleration of organ dysfunction leading to increased healthcare utilization is unknown. METHODS: This is a retrospective case-control cohort study, a secondary analysis utilizing a nationwide dataset. Patients who underwent elective surgical procedures from 2009 to 2014 were identified. Among these patients, we compared patients with obstructive sleep apnea and those without obstructive sleep apnea. Exact 1:1 matching was performed based on similar characteristics such as age, sex, geographic location, surgical facility environment, performing surgeon, and severity of illness during hospitalization. The subgroup of patients with T2DM with or without OSA was analyzed for post-discharge hospital admissions, intensive care unit (ICU) admissions, emergency room (ER) visits, and outpatient visits. RESULTS: Among 47,719 matched patients of the initial study, this subgroup included 4,567 patients with diabetes and OSA and 3,842 patients with diabetes but no OSA. In the presence of comorbid OSA, patients with T2DM had higher odds of increased healthcare utilization among all the outcomes: inpatient visits increased with an odds ratio of 2.50 (confidence interval (CI) 2.28-2.74) and ICU admissions 1.96 (CI 1.73-2.25) ER 1.93 **(CI 1.75-2.12) and outpatient visits 2.18 (CI 2.00-2.38). Future healthcare utilization per 100 patient-years was also increased significantly among all outcomes (p < 0.0001). CONCLUSIONS: In patients with diabetes undergoing elective surgery, the presence of OSA was associated with higher future healthcare utilization.

Presence of obstructive sleep apnea is associated with higher future readmissions and outpatient visits-a nationwide administrative dataset study.

BACKGROUND: Hospital readmissions and outpatient visits contribute to the significant burden on healthcare systems. Obstructive sleep apnea (OSA) is a chronic medical condition that is associated with cardiovascular comorbidities and other chronic conditions. Inpatient and outpatient healthcare utilization rates in patients with OSA following hospitalization are unclear. METHODS: This. retrospective case-control cohort study utilized a nationwide database to assess if OSA is associated with higher healthcare utilization post-hospitalization. We compared healthcare utilization among patients with OSA versus without OSA between 2009 and 2014 after matching for demographic variables, geographic location, hospital environment, reason for admission, and severity of illness during hospitalization. We measured future healthcare utilization by the number of ICU admissions, hospital admissions, emergency room visits, and outpatient visits after being discharged from the index hospitalization. RESULTS: Two equal-sized cohorts comprised of 85,912 matched pairs were obtained. The OSA cohort demonstrated significantly higher rates of future ICU admissions, hospital admissions, emergency room visits, and outpatient visits. Matching for comorbid cardiovascular conditions continued to demonstrate higher healthcare utilization in the OSA group. Short-term outcomes during the index hospitalization were relatively similar between groups. CONCLUSIONS: This retrospective database study demonstrated that OSA may be an independent marker of higher future healthcare utilization. On the other hand, the length of stay during the index hospitalization was not elevated. Prospective studies are needed to confirm these findings and investigate the impact of directing additional resources to inpatients with OSA.

Dream Enactment Behaviors Associated With Posttraumatic Stress Disorder.

The investigators aimed to draw attention to current debates surrounding the etiologies of dream enactment behaviors in patients with posttraumatic stress disorder (PTSD). The phenomenological overlap between PTSD-related nocturnal symptoms, rapid eye movement sleep behavior disorder (RBD), and trauma-associated sleep disorder (TASD) is discussed. Strategies used to diagnose and manage dream enactment behaviors, whether due to RBD or another confounding sleep disorder, are considered. Finally, the need for further research on the pathophysiological overlap and integrated treatment of PTSD, RBD, and, possibly, TASD is highlighted.

Habitual Sleep Duration and the Colonic Mucosa-Associated Gut Microbiota in Humans-A Pilot Study.

We examined the association between the colonic adherent microbiota and nocturnal sleep duration in humans. In a cross-sectional study, 63 polyp-free adults underwent a colonoscopy and donated 206 mucosal biopsies. The gut microbiota was profiled using the 16S rRNA gene sequencing targeting the V4 region. The sequence reads were processed using UPARSE and DADA2, respectively. Lifestyle factors, including sleep habits, were obtained using an interviewer-administered questionnaire. We categorized the participants into short sleepers (<6 h per night; n = 16) and normal sleepers (6-8 h per night; n = 47) based on self-reported data. Differences in bacterial biodiversity and the taxonomic relative abundance were compared between short vs. normal sleepers, followed by multivariable analysis. A false discovery rate-adjusted p value (q value) < 0.05 indicated statistical significance. The bacterial community composition differed in short and normal sleepers. The relative abundance of Sutterella was significantly lower (0.38% vs. 1.25%) and that of Pseudomonas was significantly higher (0.14% vs. 0.08%) in short sleepers than in normal sleepers (q values < 0.01). The difference was confirmed in the multivariable analysis. Nocturnal sleep duration was associated with the bacterial community composition and structure in the colonic gut microbiota in adults.

Healthcare utilization after elective surgery in patients with obstructive sleep apnea - analysis of a nationwide data set.

BACKGROUND: Obstructive sleep apnea is prevalent among those undergoing elective surgery and likely introduces a risk of adverse outcomes. To understand its impact, we aimed to compare healthcare utilization in postsurgical patients with obstructive sleep apnea compared to controls matched on the surgical care environment. METHODS: This is a retrospective case-control cohort study using a nationwide database. Among patients undergoing elective surgical procedures during 2009-2014, we compared patients with obstructive sleep apnea with those without obstructive sleep apnea. The two cohorts were matched based on age, sex, type of surgery, performing surgeon, the hospital where the procedure was performed, and various All-Patient-Refined Diagnosis-Related-Groups severity indices. The primary effect of interest was short-term healthcare utilization. We also compared long-term hospital admissions, intensive care unit admissions, emergency room visits and outpatient visits. RESULTS: 47,719 subjects and controls were matched on a 1:1 basis. As the subjects were matched, the two groups did not differ on age, percent female, and various Diagnosis-Related-Groups severity indices. The obstructive sleep apnea group had more comorbid conditions and a higher Elixhauser index. Short-term healthcare utilization measured by the length of stay and mortality related to index procedure did not increase in the sleep apnea group. In hierarchical logistical regression analysis, the presence of sleep apnea predicted higher long-term health care utilization. CONCLUSIONS: Our data suggests that the presence of sleep apnea was not associated with increased post elective surgical length of stay and mortality; however, the presence of obstructive sleep apnea was associated with long-term health care utilization.

Clinical Correlates of Dream Enactment Behaviors in Previously Deployed OEF/OIF/OND Veterans: An Exploratory Analysis.

OBJECTIVE: Veterans with posttraumatic stress disorder (PTSD) frequently report dream enactment behavior (DEB). Although DEBs are associated with PTSD symptoms, their relationship with other sleep disorders, including REM behavior disorder, warrants reexamination of their clinical correlates. METHODS: The investigators used a cross-sectional, exploratory analysis to compare demographic and clinical characteristics of veterans endorsing regularly occurring DEB compared with those endorsing no or infrequent DEB. The participants comprised a convenience sample of servicemembers who were previously deployed to Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND) and enrolled in an ongoing cohort study. RESULTS: Of the 78 eligible participants, 19 (24.4%) endorsed DEBs occurring at least once per week in the past month. Compared with participants who reported no or infrequent DEBs, participants with regularly occurring DEBs had poorer sleep quality, greater PTSD severity, a higher number of reported mild traumatic brain injuries (mTBI) with loss of consciousness, and a higher likelihood of being diagnosed with sleep disorders. After adjustment for global sleep quality, a significant association persisted between DEBs and the number of mTBI with loss of consciousness but not between DEBs and the severity of PTSD symptoms. CONCLUSIONS: These results suggest that mTBI may disrupt neural circuits regulating sleep among OIF/OEF/OND veterans. Prospective, polysomnographic assessment of muscle tone and behavioral events during REM sleep is needed to characterize the physiology of DEBs in this population.

Update on management of stable chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a major chronic debilitating condition with significant impact on quality of life, symptoms, comorbidity, health care utilization and longevity. The main pathophysiological hallmark of COPD is expiratory flow limitation which impairs the ability of respiratory system to adequately and properly ventilate. To be able to prognosticate and manage patients with COPD, various societies have developed classifications of disease severity. Current classification schemes combine three elements that include lung function, patient reported symptoms (shortness of breath) and frequency of exacerbations. Global Initiative for Obstructive Lung Disease (GOLD), an international guideline for diagnosis and management of COPD, started using this approach since the 2011 revision. Management according to this scheme has been developed and is in use. Comprehensive COPD management is multifaceted. It includes pharmacologic management, patient education, smoking cessation, influenza and pneumococcal vaccinations, depression and anxiety management, pulmonary rehabilitation, and if indicated, home oxygen therapy. The following chapter will review management recommendations currently in use for stable COPD. We intend to make the chapter to the point and practical and avoid an exhaustive review of the literature.

Non-24-Hour Sleep-Wake Circadian Rhythm Disorder in a Sighted Male With Normal Functioning.

ABSTRACT: This is a rare case of non-24-hour sleep-wake rhythm disorder in a sighted male with normal functioning. The patient, a 23-year-old doctorate graduate student, presented with difficulty falling asleep and excessive daytime sleepiness. He reported variable sleep and wake times. Overnight baseline polysomnography was unremarkable and his Multiple Sleep Latency Test was significant for short mean sleep latency. Sleep diary and actigraphy were obtained, which demonstrated a pattern of delaying of sleep and wake times each day. He had excellent symptom response to nightly melatonin.

A real-world comparison of apnea-hypopnea indices of positive airway pressure device and polysomnography.

The apnea hypopnea index (AHI) reported by positive airway pressure (PAP) device is widely used in clinical practice, yet its correlation with standardized AHI obtained during the sleep study is not established. The current study was conducted to investigate the correlation between AHI estimated by the PAP device and reported on the smart card with the AHI found during the PAP polysomnography (PSG) in the "real world" setting at an academic sleep center. We retrospectively reviewed the medical records of 280 patients who underwent a PAP titration PSG at Drexel sleep center, and were later prescribed a PAP device. The AHI was categorized in clinically relevant subgroups (as AHI ≤5 and AHI >5). The AHI at the final pressure on the PSG and the average AHI from the prescribed PAP device were compared. The results showed that in the majority (77.3%) of patients (126 of 163), the AHI from both PAP device and PSG correlated well and were in the same category (AHI ≤5 and AHI >5 respectively). The majority of patients (80.7%) with PSG AHI of <5 had PAP device AHI <5 as well. By contrast, if PSG AHI was >5, 61.5% patients reported good control, with AHI <5 on PAP device AHI. We conclude that in a majority of patients who were optimally titrated in the sleep laboratory, the PAP device continued to show optimal control at home.