COVID-19 and Sleep Disturbances: A Literature Review of Clinical Evidence.

The need for adequate good quality sleep to optimally function is well known. Over years, various physical, psychological, biological, and social factors have been investigated to understand their impact on sleep. However, understanding the etiological processes that are involved in causing sleep disturbances (SD) as impacted by stressful phases such as pandemics has not been well studied. Many such etiological and management strategies have surfaced during the latest "coronavirus disease of 2019 (COVID-19) pandemic. The occurrence of these SD in the infected and uninfected individuals poses a need to investigate factors linked to such occurrence during this phase. Some of such factors include stressful practices such as social distancing, masking, vaccines, and medications availability, changes in routines, and lifestyles. As the status of infection improved, a collective term for all the prolonged effects of COVID-19 after the resolution of the primary infection called the post-COVID-19 syndrome (PCS) surfaced. Apart from impacting sleep during the infectious phase, the aftereffects of this virus left an even greater impact during the PCS. Various mechanisms have been hypothesized to be linked to such SD during the PCS, but the available data are inconclusive. Further, the varied patterns of incidence of these SDs differed by many factors, such as age, gender, and geographical location, making clinical management even more challenging. This review elucidates the impact of coronavirus 2 (SARS-CoV-2) (COVID) disease on sleep health during the various phases of the COVID-19 pandemic. We also investigate different causal relationships, management strategies, and knowledge gaps related to SD during the COVID-19 pandemic.

Sleep and Safety among Healthcare Workers: The Effect of Obstructive Sleep Apnea and Sleep Deprivation on Safety.

Almost one billion people worldwide are affected by Obstructive Sleep Apnea (OSA). Affected individuals experience disordered breathing patterns during sleep, which results in fatigue, daytime drowsiness, and/or sleep deprivation. Working under the influence of these symptoms significantly impairs work productivity and leads to occupational accidents and errors. This impact is seen in healthcare workers (HCWs) who are not immune to these conditions. However, poorly controlled OSA in this subset of individuals takes a heavy toll on patient care due to the increased risk of medical errors and can also alter the mental and physical well-being of the affected HCW in various ways. OSA and safety issues have been recognized and mitigated among the airline and transport industries; however, the healthcare industry lags in addressing these concerns. This article reviews hypersomnolence and sleep disorder as key clinical features of OSA and their effect on HCW safety.

Current practice patterns, challenges, and educational needs of asthma care providers in the United States.

OBJECTIVE: For severe, uncontrolled asthma (SUA), a gap exists between recent scientific advances and their incorporation into clinical practice. Using a Knowledge-to-Action Framework, new knowledge can be translated into evidence-based interventions to improve outcomes. The AstraZeneca U.S. PRECISION initiative aims to apply this Framework to improve recognition and management of SUA. The study objective was to identify factors contributing to gaps in care for patients with SUA. Results from a needs assessment survey of U.S. pulmonologists and allergists/immunologists were assessed within the Knowledge-to-Action Framework to advance bench-to-bedside care. METHODS: Pulmonologists and allergists/immunologists from across the United States were invited to complete a customized, quantitative severe asthma survey in person at the 2017 American Thoracic Society annual meeting or via the Internet. Responses were summarized descriptively, and chi-squared tests evaluated associations between variables of interest. RESULTS: Overall, 140 U.S. providers responded, most of whom were pulmonologists (84%). Most (60%) practiced in a community-based setting; 40% practiced at an academic medical center. Key challenges to providing care for patients with severe asthma included insurance company requirements and identification of the pathophysiology of an individual patient's severe asthma. Traditional measures of asthma-related morbidity were ranked as highly important by significantly more respondents compared with assessment of biomarkers (p < 0.0001). Respondents generally valued online virtual self-education. CONCLUSIONS: Survey results identified unmet needs for the identification and management of patients with SUA and opportunities to improve patient outcomes through evidence-based management of SUA, including testing for biologic eligibility and subsequent use of biologic therapies.

Comorbid insomnia and sleep apnea: characterization of the syndrome and understanding its associations with comorbid sleep conditions.

PURPOSE: Obstructive sleep apnea (OSA) is traditionally associated with excessive daytime sleepiness. Insomnia is characterized by hyperarousal, and is seen as a predominant feature in a subgroup of patients with OSA. The aim of this study was to describe the prevalence of comorbid insomnia and sleep apnea (COMISA) in a sleep apnea population and to characterize its features. METHODS: This was a chart review of patients who underwent overnight polysomnography (PSG). All patients completed questionnaires with the Epworth Sleepiness Scale (ESS), and symptoms of insomnia and other sleep-related comorbidities. Patients with OSA on the PSG were included. RESULTS: A total of 296 patients with OSA were included, of which 80% reported at least 1 major symptom of insomnia: 57% reported sleep onset insomnia, 68% sleep maintenance insomnia, and 48% had early morning awakenings. COMISA (OSA plus 2 or more major symptoms of insomnia) was seen in 63%. These patients were more likely to report an abnormal ESS score, gastroesophageal reflux (GER), and restless legs (RL) than those without; no difference was seen in self-reported sleep bruxism. Among the patients with COMISA, 85% reported at least 1 representative symptom of psychophysiological insomnia (PPI); each of the 5 PPI symptoms was present in at least 40% of patients with COMISA. CONCLUSIONS: Insomnia is extremely prevalent in our population of patients with OSA, accompanied by daytime sleepiness and symptoms of PPI, GER, and RL. Further study is needed to determine the interactions between symptoms and OSA treatments in these patients.

Gender and age influence the effects of slow-wave sleep on respiration in patients with obstructive sleep apnea.

INTRODUCTION: Obstructive sleep apnea (OSA) is influenced by sleep architecture with rapid eye movement (REM) sleep having the most adverse influence, especially in women. There is little data defining the influence of slow-wave sleep (SWS) on OSA. We wished to study the influence of SWS on OSA and identify differences attributable to gender and/or age, if any. METHODS: Retrospective study of polysomnography (PSG) records of adult patients referred for diagnostic PSG. Records were excluded if they underwent split night or positive airway pressure titration studies, had <180 min of total sleep time (TST) and/or <40% sleep efficiency, or had SWS <5 min and/or <1% of TST. The apnea-hypopnea index (AHI) recorded during SWS was compared with that measured during other non-rapid eye movement (NREM) sleep and during REM sleep. The REM-SWS difference in AHI was measured, and compared between genders. RESULTS: Records from 239 patients were included. The mean AHI in all subjects was 17.7 ± 22.6. The SWS AHI was 6.8 ± 18.9, compared to the REM AHI of 24.9 ± 25.8, and NREM AHI of 15.8 ± 22.8. Females had significantly higher SWS by percentage, and lower NREM AHI (P < 0.0001) and SWS AHI (P = 0.03). Among patients with OSA (AHI ≥5), the difference between REM AHI and SWS AHI was greater in women than in men (34.2 ± 27.4 vs. 21.6 ± 26.0, P = 0.006). CONCLUSIONS: The upper airway appears to be less susceptible to OSA during SWS than during REM and other NREM sleep. This may be related to phase-specific influences on both dynamic upper airway control as well as loop gain. Gender and age appear to modify this effect.

Diagnosis of Obstructive Sleep Apnea Using Feature Selection, Classification Methods, and Data Grouping Based Age, Sex, and Race.

Obstructive sleep apnea (OSA) is a prevalent sleep disorder that affects approximately 3-7% of males and 2-5% of females. In the United States alone, 50-70 million adults suffer from various sleep disorders. OSA is characterized by recurrent episodes of breathing cessation during sleep, thereby leading to adverse effects such as daytime sleepiness, cognitive impairment, and reduced concentration. It also contributes to an increased risk of cardiovascular conditions and adversely impacts patient overall quality of life. As a result, numerous researchers have focused on developing automated detection models to identify OSA and address these limitations effectively and accurately. This study explored the potential benefits of utilizing machine learning methods based on demographic information for diagnosing the OSA syndrome. We gathered a comprehensive dataset from the Torr Sleep Center in Corpus Christi, Texas, USA. The dataset comprises 31 features, including demographic characteristics such as race, age, sex, BMI, Epworth score, M. Friedman tongue position, snoring, and more. We devised a novel process encompassing pre-processing, data grouping, feature selection, and machine learning classification methods to achieve the research objectives. The classification methods employed in this study encompass decision tree (DT), naive Bayes (NB), k-nearest neighbor (kNN), support vector machine (SVM), linear discriminant analysis (LDA), logistic regression (LR), and subspace discriminant (Ensemble) classifiers. Through rigorous experimentation, the results indicated the superior performance of the optimized kNN and SVM classifiers for accurately classifying sleep apnea. Moreover, significant enhancements in model accuracy were observed when utilizing the selected demographic variables and employing data grouping techniques. For instance, the accuracy percentage demonstrated an approximate improvement of 4.5%, 5%, and 10% with the feature selection approach when applied to the grouped data of Caucasians, females, and individuals aged 50 or below, respectively. Furthermore, a comparison with prior studies confirmed that effective data grouping and proper feature selection yielded superior performance in OSA detection when combined with an appropriate classification method. Overall, the findings of this research highlight the importance of leveraging demographic information, employing proper feature selection techniques, and utilizing optimized classification models for accurate and efficient OSA diagnosis.

Validation of the Urdu version of the Epworth Sleepiness Scale.

OBJECTIVE: To translate and validate the Epworth Sleepiness Scale (ESS) for use in Urdu-speaking population. METHODS: The original Epworth Sleepiness Scale was translated into the Urdu version (ESS-Ur) in three phases - translation and back-translation; committee-based translation; and testing in bilingual individuals. The final was subsequently tested on 89 healthy bilingual subjects between February and April, 2010, to assess the validity of the translation compared to the original version. The subjects were students and employees of Dow University of Health Sciences, Karachi. RESULTS: Both English and Urdu versions of the Epworth Sleepiness Scale were administered to 59 (67%) women and 30 (33%) men. The mean composite Epworth score was 7.53 in English language and 7.7 in the Urdu version (p=0.76). The translated version was found to be highly correlated with the original scale (rho=0.938; p<.01). CONCLUSIONS: The study validated the scale's Urdu version as an effective tool for measuring daytime sleepiness in Urdu-speaking population. Future studies assessing the validity of such patients with sleep disorders need to be undertaken.

The NAMES assessment: a novel combined-modality screening tool for obstructive sleep apnea.

PURPOSE: Obstructive sleep apnea (OSA) remains underdiagnosed, despite our understanding of its impact on general health. Current screening methods utilize either symptoms or physical exam findings suggestive of OSA, but not both. The purpose of this study was to develop a novel screening tool for the detection of OSA, the NAMES assessment (neck circumference, airway classification, comorbidities, Epworth scale, and snoring), combining self-reported historical factors with physical exam findings. METHODS: Subjects were adults without previously diagnosed OSA, referred to a community sleep center for suspicion of OSA. General health, Epworth Sleepiness Scale (ESS), and Berlin questionnaires were completed, and a physical exam focusing on modified Friedman (MF) grade, body mass index (BMI), and neck circumference (NC) was performed prior to polysomnography. OSA was defined by a respiratory disturbance index ≥15. Each variable was dichotomized, and cutoff values were determined for the NAMES tool in a pilot group of 150 subjects. The NAMES score was calculated from NC, MF, comorbidities, ESS, and loud snoring values. The performances of the NAMES, Berlin questionnaire, and ESS screening tests in predicting OSA were then compared in a validation group of 509 subjects. RESULTS: In the pilot population, the cutoff value for the composite NAMES tool was calculated at ≥3 points. In the validation group, NAMES demonstrated similar test characteristics to the Berlin questionnaire, and sensitivity was better than that seen with the Epworth scale. The addition of BMI and gender to the tool improved screening characteristics. CONCLUSIONS: The NAMES assessment is an effective, inexpensive screening strategy for moderate to severe OSA.

Influence of gender on continuous positive airway pressure requirements in patients with obstructive sleep apnea syndrome.

INTRODUCTION: Gender differences have been noted in key aspects of upper airway physiology and pathophysiology of obstructive sleep apnea (OSA). We postulate that these will lead to disparities in pharyngeal collapsibility and, consequently, positive airway pressure requirements of patients with OSA. METHODS: A retrospective review of 95 adult patients (56 women, 39 men) with OSA was done. Patients who underwent continuous positive airway pressure (CPAP) titration were included in the study. RESULTS: The study groups were similar with regard to the severity of OSA (median apnea-hypopnea index of 34 in men and 24 in women, p = 0.13). The men were older and less obese than the women (mean age of 46 and 41 years, p = 0.03, BMI of 42 and 49 kg/m(2), p < 0.001, in men and women, respectively); Epworth score was similar in the two groups (12 vs.11, p = 0.91). CPAP requirement was higher in men than in women (12.7 vs. 10.2, p < 0.0001). The effect of gender on CPAP requirement was found to be significant even when confounding variables were accounted for using linear regression. CONCLUSION: Men with OSA are more likely to require higher levels of CPAP support than women. The effect of gender on CPAP requirement persisted even after correcting for the severity of OSA.

Gender and ethnic differences in prevalence of self-reported insomnia among patients with obstructive sleep apnea.

BACKGROUND: Insomnia and obstructive sleep apnea (OSA) are the two most common sleep disorders. Studies have shown that complaints of insomnia are prevalent among sleep clinic patients evaluated for OSA. Less is known about the gender and ethnic variations in this association. OBJECTIVES: This paper aims to study the influence of gender and ethnicity in the prevalence of insomnia in patients with OSA and explore the association between these two disorders with an emphasis on psychophysiologic insomnia. METHODS AND MEASUREMENTS: We reviewed case files, including self-reported questionnaires and polysomnography studies of 300 OSA patients [apnea-hypopnea index (AHI) of >10] from three ethnic groups--Caucasian, Hispanic, and African American, 50 patients each, male and female, seen at a tertiary care county hospital adult sleep center. Self-reported insomnia was classified as sleep onset insomnia, sleep maintenance insomnia, or insomnia with early morning awakening. Psychophysiologic insomnia was documented if the patient reported two of the following five symptoms: racing thoughts when trying to sleep, increased muscle tension when trying to sleep, fear of being unable to sleep, fear of being unable to fall back to sleep after waking up, and lying in bed worrying. Fischer exact tests for each contingency table were run using SPSS. RESULTS: Among OSA patients, women were older, had higher body mass index, and lower AHI at the time of diagnosis, compared to men. Insomnia was more prevalent among patients with OSA (84%) than the reported 30% among general adult population. Sleep onset insomnia was reported more frequently by women (62%) than men (53%) (p = 0.03). Similarly self-reported psychophysiologic insomnia also showed a female preponderance (53% vs. 45%, p = 0.03). Caucasian women had the highest rate of self-reported sleep maintenance insomnia (80%). Hispanic women are more likely to complain of symptoms suggestive of psychophysiologic insomnia (58%). CONCLUSIONS: There is a higher prevalence of insomnia in OSA patients. Ethnicity and gender possibly exhibit a complex and significant influence on the reported subtype of insomnia. Further larger studies may help confirm, as well as clarify, mechanisms that underlie the ethnic and gender differences that we have noted.

Standardization of quality assurance for sleep technologist: a model.

INTRODUCTION: Since the last decade, there has been a tremendous growth of sleep centers in the US to meet the increasing need of diagnosing and treating sleep disorders. However, this unregulated growth has resulted in tremendous variance in the quality of sleep centers across the nation. The American Academy of Sleep Medicine, in an attempt to provide a benchmark standard, has introduced a voluntary accreditation process, part of which involves assessment of technical quality parameters. However, measuring technical quality is not easy. HYPOTHESIS: We undertook a study to determine if the implementation of point system and schematic feedback on technologist performance can result in improvement and tracking of their performance. MATERIALS AND METHODS: We randomly reviewed 100 charts from the preimplementation phase as control and 1,739 charts from the post implementation of the point system phase as study group. RESULTS: There was a statistically significant difference in the score among technologist between the control and study groups with the average being 75 +/- 4.12 and 87.53 +/- 0.91, respectively, with a p value being 0.0001. CONCLUSION: Evaluating the performance of the sleep technologist can be a way to track and monitor their performance in a standardized way and to identify weakness at an earlier stage. We present a system, which we have developed and implemented at our sleep center, as a possible model of assessing and subsequently standardizing technical quality for polysomnography.

Sexual dysfunction in women with obstructive sleep apnea.

BACKGROUND: Female sexual dysfunction is vastly under-recognized but has been previously described in chronic disease states. Sexual dysfunction in male patients with obstructive sleep apnea (OSA) is well described, but not in females. OBJECTIVE: The objective of this study was to assess the prevalence of sexual dysfunction in women with OSA. METHODS: We studied 21 consecutive pre-menopausal women with OSA, referred to our sleep lab, and who had a positive study for sleep apnea (respiratory disturbance index (RDI) > 5), and 11 healthy pre-menopausal women were included as the control group. Subjects were administered the Female Sexual Function Index (FSFI) questionnaire and a mood scale-Profile of Mood States. RESULTS: Of the study group, 11 women (52.4%) had FSFI scores in the poor range (<23) as compared to the control group, in which none of the women (0%) had FSFI scores in the poor range (<23). Negative mood domain scores were not different in patients with poor FSFI compared to patients with normal FSFI scores. There was no correlation between obesity, severity of sleep apnea, or mood disorders on overall scores of sexual dysfunction. Among individual domains, there was a correlation between RDI and arousal scores. CONCLUSION: In our study, we have found that prevalence of sexual dysfunction is high among women with OSA. Physicians should routinely screen and evaluate women with OSA for sexual dysfunction.

Optimizing performance of semi-continuous cell culture in an ambr15™ microbioreactor using dynamic flux balance modeling.

The ambr bioreactors are single-use microbioreactors for cell line development and process optimization. With operating conditions for large-scale biopharmaceutical production properly scaled down, microbioreactors such as the ambr15™ can potentially be used to predict the effect of process changes such as modified media or different cell lines. While there have been some recent studies evaluating the ambr15™ technology as a scale-down model for fed-batch operations, little has been reported for semi-continuous or continuous operation. Gassing rates and dilution rates in the ambr15™ were varied in this study to attempt to replicate performance of a perfusion process at the 5 L scale. At both scales, changes to metabolite production and consumption, and cell growth rate and therapeutic protein production were measured. Conditions were identified in the ambr15™ bioreactor that produced metabolic shifts and specific metabolic and protein production rates that are characteristic of the corresponding 5 L perfusion process. A dynamic flux balance (DFB) model was employed to understand and predict the metabolic changes observed. The DFB model predicted trends observed experimentally, including lower specific glucose consumption and a switch from lactate production to consumption when dissolved CO2 was maintained at higher levels in the broth. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:420-431, 2018.

Sleepiness in medical residents: impact of mandated reduction in work hours.

OBJECTIVES: To assess the sleepiness among Family Practice residents using subjective data, the Epworth sleepiness scale (ESS), as well as objective assessment, the multiple sleep latency test (MSLT). METHOD: We conducted the study on Family Practice residents at Texas A&M University, Corpus Christi. Sixteen residents, aged 21-40 yrs, were recruited and divided into two groups. The study group was comprised of residents who were on night-float rotation for at least three days and underwent MSLT post-call, and the control group was comprised of residents who were not on night-float and were not post-call. Daytime sleepiness was evaluated using both the ESS and MSLT. Respondents also completed a questionnaire assessing their beliefs regarding effects of sleep loss. RESULTS: Sleep latencies <10 min were observed in 6 out of the 8 day shift-work interns, while only 1 out of 8 night-float residents had an average sleep latency <10 min (p=0.0195). Following night-float, despite less sleep, residents had sleep latencies which were higher [14.2 (+/-5.0) min] than those in the control group [8.4 (+/-5.4) min, (p=0.043)]. Despite the difference in objective sleepiness, subjective sleepiness (Epworth scores) did not differ. Over 80% of interns reported having driven while sleepy. CONCLUSION: Sleepiness continues to be a significant issue among medical residents despite recently mandated reductions in resident work hours. MSLT values in the pathologic range are seen in the majority of residents studied, but in those who were post-night call there seemed to be a paradoxical improvement.

Sleep Quality and Vigilance Differ Among Inpatient Nurses Based on the Unit Setting and Shift Worked.

OBJECTIVES: Sleepiness in nurses has been shown to impact patient care and safety. The objectives of this study are to measure sleep quality, sleepiness, fatigue, and vigilance in inpatient nurses and to assess how setting (intensive care unit versus the general floor) and shift worked (day versus night) affect these measures. METHODS: Nurses from both the ICU and floor were included in the study. Participants completed questionnaires assessing self-reported sleep quality (Pittsburgh Sleep Quality Index, PSQI), sleepiness (Stanford Sleepiness Scale and Epworth Sleepiness Scale, ESS), and fatigue (Fatigue Severity Scale, FSS). Vigilance was measured by means of the psychomotor vigilance test (PVT), before and after a 12-hour duty shift. RESULTS: The ESS was abnormal in 22% of all nurses, the FSS was abnormal in 33%, and the global PSQI was abnormal in 63%. More ICU nurses than floor nurses reported abnormal sleep quality (component 5) on the PSQI. Sleep medication use (PSQI component 6) was higher in night shift nurses. The FSS was greater in night shift nurses. On preshift PVT testing, day-shift nurses overall provided faster mean reaction time (RT) than night-shift nurses. ICU nurses working the day shift made more than twice as many total errors and false starts than day shift floor nurses. Floor nurses demonstrated a significant decrease from preshift to postshift in the mean of the fastest 10% RT. CONCLUSIONS: Our data indicate that a significant number of inpatient nurses have impaired sleep quality, excessive sleepiness, and abnormal fatigue, which may place them at a greater risk of making medical errors and harming patients; these problems are especially pronounced in night shift workers. PVT results were inconsistent, but floor and day shift nurses performed better on some tasks than ICU and night shift nurses.

Sleep Habits of Elementary and Middle School Children in South Texas.

Background. Sleep difficulties, including insufficient sleep and inadequate sleep hygiene, have been prevalent among children. Sleep deprivation can lead to poor grades, sleepiness, and moodiness. We undertook this study to assess the prevalence of sleep abnormalities among elementary and middle school students in South Texas and how the groups compare with one another. Method. After approval from the appropriate school district for a sleep education program, a baseline survey was taken of elementary and middle school students, using the Children's Sleep Habit Questionnaire-Sleep Self-Report Form, which assessed the domains of bedtime resistance, sleep onset delay, sleep anxiety, sleep duration, night awakening, and daytime sleepiness. Results. The survey was completed by 499 elementary and 1008 middle school children. Trouble sleeping was reported by 43% in elementary school, compared with 29% of middle school children. Fifty percent of middle school children did not like sleeping, compared with 26% in elementary school. Bedtime resistance, sleep onset delay, and nighttime awakening were more common among elementary school students. Daytime sleepiness was more common among the middle school children when compared to elementary school children. Conclusions. Sleep abnormalities are present in elementary school children with changes in sleep habits into middle school.

L-NAME differentially alters ventilatory behavior in Sprague-Dawley and Brown Norway rats.

Nitric oxide (NO) is a regulating factor in respiration. The question was whether NO synthase (NOS) blockade would affect posthypoxic ventilatory behavior similarly in two rat strains with known differences in steady-state hypoxic and hypercapnic responses and in posthypoxic ventilatory behavior. Ventilatory behavior [respiratory frequency (f) and minute ventilation (VE)] was measured by body plethysmography on unanesthetized, unrestrained adult male Sprague-Dawley (SD; n = 8) and Brown Norway rats (BN; n = 8) at baseline and 1 min after rapid transition to 100% O(2) after 5 min of isocapnic hypoxia (10% O(2)-3% CO(2)-balance N(2)). Testing was performed 30 min after intraperitoneal injection of either saline (vehicle) or 100 mg/kg of N(G)-nitro-L-arginine methyl ester (L-NAME). Resting f and VE increased after L-NAME in both strains, more markedly in SD compared with BN (77 vs. 47% for f, and 42 vs. 16% for VE, respectively; P < 0.05). With vehicle, posthypoxic f and VE decline (Dejours phenomenon) was present only in BN and was absent in SD. With L-NAME, the Dejours phenomena were still present in BN but also were apparent in SD (f: 95.3 vs. 134.4 beats/min at baseline; VE: 66.3 vs. 88.8 ml/min at baseline; P < 0.05). Thus NOS blockade results in a strain-specific alteration in resting ventilation and uncovers the Dejours phenomenon in the SD strain.

Periodic breathing in the mouse.

The hypothesis was that unstable breathing might be triggered by a brief hypoxia challenge in C57BL/6J (B6) mice, which in contrast to A/J mice are known not to exhibit short-term potentiation; as a consequence, instability of ventilatory behavior could be inherited through genetic mechanisms. Recordings of ventilatory behavior by the plethsmography method were made when unanesthetized B6 or A/J animals were reoxygenated with 100% O(2) or air after exposure to 8% O(2) or 3% CO(2)-10% O(2) gas mixtures. Second, we examined the ventilatory behavior after termination of poikilocapnic hypoxia stimuli in recombinant inbred strains derived from B6 and A/J animals. Periodic breathing (PB) was defined as clustered breathing with either waxing and waning of ventilation or recurrent end-expiratory pauses (apnea) of > or = 2 average breath durations, each pattern being repeated with a cycle number > or = 3. With the abrupt return to room air from 8% O(2), 100% of the 10 B6 mice exhibited PB. Among them, five showed breathing oscillations with apnea, but none of the 10 A/J mice exhibited cyclic oscillations of breathing. When the animals were reoxygenated after 3% CO(2)-10% O(2) challenge, no PB was observed in A/J mice, whereas conditions still induced PB in B6 mice. (During 100% O(2) reoxygenation, all 10 B6 mice had PB with apnea.) Expression of PB occurred in some but not all recombinant mice and was not associated with the pattern of breathing at rest. We conclude that differences in expression of PB between these strains indicate that genetic influences strongly affect the stability of ventilation in the mouse.

A Management Guideline for Obesity-Hypoventilation Syndromes.

A survey of our pulmonary service revealed little consensus as to the definition, work-up, and management of hypoventilation, more often encountered in the presence of obesity. If hypoventilation is defined by an arterial carbon dioxide level above 45mmHg, 22% of artrial blood gas samples over a 5-month period met this criterium, suggesting a high Oany-causeO prevalence. This article presents the rationale and explanation for a management protocol for obesity-hypoventilation that is currently being assessed in the VA Medical Center and Case Western Reserve University training program in Pulmonary and Critical Care Medicine.

A multicenter prospective comparative effectiveness study of the effect of physician certification and center accreditation on patient-centered outcomes in obstructive sleep apnea.

OBJECTIVES: To study the effect of sleep center accreditation and Sleep Medicine board certification of physicians on patient-centered outcomes in obstructive sleep apnea (OSA). DESIGN: Prospective, multicenter, comparative effectiveness study. SETTING: Four sleep centers. PATIENTS: 502 patients with OSA. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Patients at two accredited and two non-accredited centers underwent polysomnography at participating locations and completed validated questionnaires, with objective measurement of positive airway pressure (PAP) therapy adherence performed three months after therapy initiation. The proportion of patients (age 53 ± 13[SD] years; 26% women; and body mass index 33.6 ± 7.2 kg/m(2)) who were adherent to PAP therapy by Medicare guidelines (> 70% of nights with ≥ 4 h use over a 30-day period) was greater in accredited (79%) than non-accredited sites (64%; p = 0.004). After adjustment for confounding variables, patients who received care from accredited centers (odds ratio [OR] 2.2, 95% confidence interval [CI], 1.2-4.2; p = 0.016) and certified physicians (OR 2.3, 95% CI, 1.3-4.0; p = 0.005) were more likely to be adherent to PAP therapy than those who received care from non-accredited centers and non-certified physicians. Patient satisfaction was associated with greater education received from physician (OR 4.6; 95% CI 2.3-9.3); greater risk perception (OR 2.7; 95% CI 1.0-7.4); physician certification (OR 2.1; 95% CI 1.1-4.2); and inversely related to delays in care (OR 0.5; 95% CI 0.3-0.9; p < 0.05). Such delays were inversely related to accreditation-certification status (p < 0.0001). CONCLUSIONS: In patients with OSA, accreditation-certification status of sleep centers and physicians was associated with better PAP adherence, better patient education, better patient satisfaction, and greater timeliness. COMMENTARY: A commentary on this article appears in this issue on page 251. CITATION: Parthasarathy S; Subramanian S; Quan SF. A multicenter prospective comparative effectiveness study of the effect of physician certification and center accreditation on patient-centered outcomes in obstructive sleep apnea.