Sleep Apnea Syndromes: Kapur V

Morgenthaler TI, Aurora RN, Brown T, Zak R, Alessi C, Boehlecke B, Chesson AL, Friedman L, Kapur V, Maganti R, Owens J, Pancer J, Swick TJ, Anonymous00064, Anonymous00065. · Mayo Clinic, Rochester MN, USA. · Sleep. · Pubmed #18220088 links to  free full text

Abstract: These practice parameters are an update of the previously published recommendations regarding the use of autotitrating positive airway pressure (APAP) devices for titrating pressures and treating adult patients with obstructive sleep apnea syndrome. Continuous positive airway pressure (CPAP) at an effective setting verified by attended polysomnography is a standard treatment for obstructive sleep apnea (OSA). APAP devices change the treatment pressure based on feedback from various patient measures such as airflow, pressure fluctuations, or measures of airway resistance. These devices may aid in the pressure titration process, address possible changes in pressure requirements throughout a given night and from night to night, aid in treatment of OSA when attended CPAP titration has not or cannot be accomplished, or improve patient comfort. A task force of the Standards of Practice Committee of the American Academy of Sleep Medicine has reviewed the literature published since the 2002 practice parameter on the use of APAP. Current recommendations follow: (1) APAP devices are not recommended to diagnose OSA; (2) patients with congestive heart failure, patients with significant lung disease such as chronic obstructive pulmonary disease; patients expected to have nocturnal arterial oxyhemoglobin desaturation due to conditions other than OSA (e.g., obesity hypoventilation syndrome); patients who do not snore (either naturally or as a result of palate surgery); and patients who have central sleep apnea syndromes are not currently candidates for APAP titration or treatment; (3) APAP devices are not currently recommended for split-night titration; (4) certain APAP devices may be used during attended titration with polysomnography to identify a single pressure for use with standard CPAP for treatment of moderate to severe OSA; (5) certain APAP devices may be initiated and used in the self-adjusting mode for unattended treatment of patients with moderate to severe OSA without significant comorbidities (CHF, COPD, central sleep apnea syndromes, or hypoventilation syndromes); (6) certain APAP devices may be used in an unattended way to determine a fixed CPAP treatment pressure for patients with moderate to severe OSA without significant comorbidities (CHF, COPD, central sleep apnea syndromes, or hypoventilation syndromes); (7) patients being treated with fixed CPAP on the basis of APAP titration or being treated with APAP must have close clinical follow-up to determine treatment effectiveness and safety; and (8) a reevaluation and, if necessary, a standard attended CPAP titration should be performed if symptoms do not resolve or the APAP treatment otherwise appears to lack efficacy.

Morgenthaler TI, Kapen S, Lee-Chiong T, Alessi C, Boehlecke B, Brown T, Coleman J, Friedman L, Kapur V, Owens J, Pancer J, Swick T, Anonymous00044, Anonymous00045. · Sleep Disorders Center, Pulm Crit Care Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. · Sleep. · Pubmed #16944671 No free full text.

Abstract: Therapies for obstructive sleep apnea other than positive airway pressure, oral appliances, and surgical modifications of the upper airway are reviewed in this practice parameter. Several of these therapies such as weight loss and positional therapy hold some promise. Others, such as serotonergic agents, may gain credibility in the future but lack well-designed clinical trials. No practice parameters could be developed for a number of possible therapeutic modalities that had little or no evidence-based data on which to form a conclusion. The role of an organized, targeted weight-loss program either as a single therapy or as a supplement to PAP needs to be clarified. Although bariatric surgery is increasingly performed for refractory medically complicated obesity, its long-term effectiveness in treatment of obstructive sleep apnea in morbidly obese patients is not yet demonstrated. Positional therapy, or methods for preventing sleep in the supine position, has probably been underutilized due to lack of easily measured predictive factors and randomized controlled trials.

Redline S, Budhiraja R, Kapur V, Marcus CL, Mateika JH, Mehra R, Parthasarthy S, Somers VK, Strohl KP, Sulit LG, Gozal D, Wise MS, Quan SF. · Department of Pediatrics, Case Western Reserve University, Cleveland, OH, WA 44106-6033, USA. · J Clin Sleep Med. · Pubmed #17557426 No free full text.

Abstract: The American Academy of Sleep Medicine Task Force on Respiratory Scoring reviewed the evidence that addresses: the validity of specific sensors in detecting airflow, tidal volume, oxyhemoglobin saturation, and CO2; the reliability of specific scoring approaches for quantifying sleep related breathing disorders (SRBD); and the validity of using various definitions of the apnea hypopnea index (AHI) as assessed by the strength and consistency of associations with several comorbidities (hypertension, cardiovascular disease, sleepiness, impaired quality of life, and accidents). The evidence was based on a literature search of relevant articles published through December 2004, which resulted in identifying and extracting data from 182 articles, which were graded using standardized approaches. Diverse physiological sensors have been utilized to quantify airflow limitation in patients with suspected SRBD. Although thermistry appears appropriate for identifying apneas, the available evidence did not indicate it provides valid quantification of airflow reduction. The emerging evidence evaluating the accuracy of signal detection against the gold standard measurements (e.g., pneumotachography) suggested the superiority of inductance plethysmography and nasal pressure transducers for detection of hypopneas, with some evidence that recordings from a nasal pressure transducer may better approximate flow/volume than uncalibrated inductance plethysmography. However, since the nasal pressure transducer has only recently been incorporated into large-scale studies, there are as of yet few data that address the predictive value of transducer-identified events relative to clinical or physiological outcomes. Very few studies directly compared the validity of alternative approaches for defining the duration, amplitude change, and use of corroborative data from desaturation or arousal for defining hypopneas. Many observational studies utilizing various designs and approaches for event detection have shown significant associations between measures of SRBD and health outcomes. Data from the 2 largest sleep cohort studies, the Sleep Heart Health Study and the Wisconsin Sleep Cohort, both used definitions of hypopneas based on "discernible" reductions of inductance plethysmography signals with associated desaturation and showed that the derived AHIs using these hypopnea definitions correlated with various indices of morbidity. However, it is not clear whether alternative definitions would provide comparable if not better prediction, or whether optimal approaches for event identification would vary for different outcomes. Despite these limitations, forming a consensus on optimal approaches for recording and measuring respiratory events is an important step toward generating data from different clinical or research laboratories that can be compared. However, additional research is needed, including direct comparisons of alternative measuring approaches for predicting clinical outcomes, with a need to address these issues in large samples across the age spectrum and with inclusion of promising new technology.

Boyer S, Kapur V. · Pulmonary and Critical Care Medicine, University of Washington, Sleep Disorders Center, Seattle, 98104, USA. · Curr Opin Pulm Med. · Pubmed #14534396 No free full text.

Abstract: PURPOSE OF REVIEW: There is growing awareness of the significance of obstructive sleep apnea in the general population and in the medical community and, as a result, there is a growing demand for diagnosis and treatment. Attended, in-laboratory polysomnography is resource intensive and not readily available in some communities. Alternate diagnostic strategies have been proposed including the use of home sleep studies. Although these portable systems have been in use for many years, only in the past few years have a significant number of studies been performed to evaluate these systems in the home setting. The use of actigraphy and peripheral arterial tonometry for diagnostic purposes has also recently been investigated. RECENT FINDINGS: In the laboratory setting, measurements of sleep-disordered breathing with specific portable sleep systems correspond well with measurements provided by standard polysomnography. In the home setting, portable systems demonstrate several important limitations including lost or inadequate data collection, logistic concerns, and mildly reduced diagnostic accuracy. Data regarding the potential cost benefit of home studies is inconclusive. SUMMARY: Home polysomnography is a viable option for evaluating patients with moderate or high clinical suspicion for sleep-disordered breathing. However, patients with failed or equivocal home studies and those with negative studies but persistent symptoms should undergo standard polysomnography. Further investigations are needed to compare long-term outcomes in patients evaluated using portable devices versus standard polysomnography.

Burns SP, Rad MY, Bryant S, Kapur V. · VA Puget Sound Health Care System Spinal Cord Injury Service, Seattle, Washington 98108, USA. · Am J Phys Med Rehabil. · Pubmed #16034232 No free full text.

Abstract: OBJECTIVE: Although numerous studies have documented a high prevalence of sleep apnea in persons with spinal cord injury, relatively little has been published regarding treatment of sleep apnea in this population. The purpose of this study was to describe long-term treatment outcomes and side effects of sleep apnea treatment in persons with spinal cord injury. DESIGN: Descriptive, postal mail survey to spinal cord injury individuals with sleep apnea followed by a Veterans Affairs Spinal Cord Injury Service. RESULTS: The response rate to the mailed survey was 54%, with complete surveys obtained from 40 individuals with spinal cord injury and sleep apnea. The majority of participants (93%) had been diagnosed with sleep apnea through routine clinical care, and patients had been diagnosed a mean of 4 yrs earlier. Continuous positive airway pressure was the most commonly used treatment. Continuous positive airway pressure was tried by 80% of patients, and of these, 63% continued to use continuous positive airway pressure, with mean usage 6.5 nights per week and 6.9 hrs per night. Continuous positive airway pressure was rated as beneficial in comparison with its side effects. The most common side effects were nasal congestion and mask discomfort. CONCLUSION: Many spinal cord injury individuals with sleep apnea become long-term users of continuous positive airway pressure and perceive a subjective benefit from the treatment.

Weaver EM, Kapur V, Yueh B. · Department of Otolaryngology-Head and Neck Surgery, Sleep Disorders Center, Washington, USA. · Arch Otolaryngol Head Neck Surg. · Pubmed #15096430 links to  free full text

Abstract: BACKGROUND: While obstructive sleep apnea syndrome is defined by both polysomnographic (PSG) abnormalities and symptoms, severity is quantified primarily by the apnea-hypopnea index (AHI) alone. OBJECTIVE: To determine the correlation between standard PSG indices (AHI and others) and self-reported sleepiness, mental health status, and general health in patients with sleep apnea. DESIGN: Cross-sectional study. SETTING: University-affiliated outpatient sleep laboratory. PATIENTS: Ninety-six consecutive patients with PSG-confirmed sleep apnea (AHI >or=5). MEASUREMENTS: Patients completed a questionnaire that included the Epworth Sleepiness Scale, Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) mental health domain, and self-rated health on the evening of diagnostic PSG. Spearman correlation coefficients were computed. This sample had 85% power to detect a correlation of 0.3 or greater. The associations between PSG indices and self-reported measures were further assessed with multivariable regression techniques, adjusting for age, sex, body mass index, comorbidity, and PSG type. RESULTS: The PSG parameters correlated poorly with self-reported measures (15 correlations; range of magnitude, 0.004-0.24; mean, 0.09). AHI was not associated with self-reported sleepiness or general health, and it was associated with the SF-36 Health Status mental health domain only on multiple linear regression (P =.04) but not on multiple logistic regression (adjusted odds ratio, 1.02; 95% confidence interval, 1.00-1.04; P =.09). CONCLUSIONS: In general, PSG measures, and AHI in particular, correlated poorly with self-reported measures in a clinical sleep laboratory sample. After adjustment for potentially confounding variables, weak associations were found between some PSG indices and selected self-reported measures. These findings suggest that sleep apnea disease burden should be quantified with both physiologic and subjective measures.

Redline S, Kirchner HL, Quan SF, Gottlieb DJ, Kapur V, Newman A. · Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, Ohio, USA. · Arch Intern Med. · Pubmed #14980992 links to  free full text

Abstract: BACKGROUND: Polysomnography is used to assess sleep quality and to gauge the functional effect of sleep disorders. Few population-based data are available to estimate the variation in sleep architecture across the population and the extent to which sleep-disordered breathing (SDB), a common health condition, contributes to poor sleep independent of other factors. The objective of this study was to describe the population variability in sleep quality and to quantify the independent associations with SDB. METHODS: Cross-sectional analyses were performed on data from 2685 participants, aged 37 to 92 years, in a community-based multicenter cohort study. Dependent measures included the percentage time in each sleep stage, the arousal index, and sleep efficiency. Independent measures were age, sex, ethnicity, comorbidity status, and the respiratory disturbance index. RESULTS: Lighter sleep was found in men relative to women and in American Indians and blacks relative to other ethnic groups. Increasing age was associated with impaired sleep in men, with less consistent associations in women. Notably, women had, on average, 106% more slow wave sleep. Sleep-disordered breathing was associated with poorer sleep; however, these associations were generally smaller than associations with sex, ethnicity, and age. Current smokers had lighter sleep than ex-smokers or never smokers. Obesity had little effect on sleep. CONCLUSIONS: Sleep architecture varies with sex, age, ethnicity, and SDB. Individual assessment of the effect of SDB on sleep quality needs to account for other host characteristics. Men, but not women, show evidence of poorer sleep with aging, suggesting important sex differences in sleep physiology.

Holmes MD, Chang M, Kapur V. · Department of Neurology, University of Washington School of Medicine, Seattle, USA. · Neurology. · Pubmed #14581678 No free full text.

Abstract: Vagal nerve stimulation (VNS) therapy affects respiration during sleep and can interrupt sleep. VNS has also been noted to improve excessive daytime sleepiness. The authors present a patient who developed excessive daytime sleepiness after VNS placement, as a consequence of apneas and arousals associated with intermittent electrical stimulation of the left vagus nerve.

Watson NF, Kapur V. · Department of Neurology, Sleep Disorders Center, University of Washington, Seattle, WA 98104, USA. · Chest. · Pubmed #12853553 links to  free full text

Abstract: We report the case of a severely mentally handicapped 30-year-old woman with Sturge-Weber syndrome who developed obstructive sleep apnea syndrome (OSA) following esophageal aspiration of two foreign bodies, which were discovered incidentally during a neck CT scan. Initial polysomnography findings revealed significant OSA with an apnea-hypopnea index (AHI) of 40.8 events per hour. Repeat polysomnography following endoscopic removal of the foreign bodies revealed marked improvement of her OSA with a decrease of AHI to 15.6 events per hour. Our report highlights the importance of considering foreign body aspiration as a cause for OSA in mentally handicapped patients.

Kapur V, Strohl KP, Redline S, Iber C, O'Connor G, Nieto J. · Department of Medicine, University of Washington, Seattle, USA. · Sleep Breath. · Pubmed #12075479 No free full text.

Abstract: We hypothesize that clinical recognition rates for obstructive sleep apnea-hypoapnea syndrome (OSAHS) are influenced by comorbidity and demographic factors. Data on medical disorders, symptoms of sleep disorders, and cardiovascular risk factors gathered from 15,699 individuals in the Sleep Heart Health Study were compared. Participants were classified into three groups: those with a self-reported physician diagnosis of OSAHS, those with self-reported physician-diagnosed and -treated OSAHS, and those reporting both frequent snoring and daytime sleepiness (two-symptom group). Among all participants, 4.1% reported two symptoms (range across sites: 1.55 to 7.23%), whereas 1.6% reported a physician diagnosis of OSAHS (range: 0.66 to 2.88%) and 0.6% reported physician diagnosis and treatment (range: 0.11 to 0.88%). Recognized OSAHS groups were similar to the two-symptom group in age, having a sleeping partner, measured blood pressure, total cholesterol, and race. In a logistic model that included age along with characteristics found to vary significantly among the three groups (gender, body mass index [BMI], high-density lipoprotein cholesterol levels, hypertension), only male gender and BMI were increased in those with physician-diagnosed and -treated OSAHS. We conclude that disparities (especially in women and in those with lower BMI) exist between current recognition rates for OSAHS and the estimated prevalence by symptom report across the United States.

Burns SP, Kapur V, Yin KS, Buhrer R. · Department of Rehabilitation Medicine, University of Washington, Seattle, Washington, USA. · Spinal Cord. · Pubmed #11224009 links to  free full text

Abstract: OBJECTIVE: To characterize a population of spinal cord injury (SCI) patients with sleep apnea, and to determine associated factors and comorbidities. STUDY DESIGN: Population-based retrospective case-control study. SUBJECTS: 584 male patients served by a Veterans Affairs SCI service. MEASURES: Medical records were reviewed for sleep apnea diagnosis, demographic information, neurologic characteristics, and treatments received. Sleep study reports were not available to determine the nature of abnormal respiratory events (ie central, obstructive, hypoventilation). For each case with tetraplegia, a control tetraplegic subject without sleep apnea diagnosis was selected. RESULTS: We identified 53 subjects with diagnosed sleep apnea: 42 tetraplegic, 11 paraplegic. This represented 14.9% of all tetraplegic and 3.7% of all paraplegic patients in the population (P<0.0001 for comparison of tetraplegic and paraplegic proportions). In tetraplegic subjects, sleep apnea was associated with obesity and more rostral motor level, but not with ASIA Impairment Scale. Medical comorbidities associated with sleep apnea in non-SCI patients, such as hypertension, were more common in case subjects. Less than half of case subjects were receiving some form of treatment. For motor-complete tetraplegics, long-term positive airway pressure treatment was less common with motor level C5 and above compared to C6 and below. CONCLUSION: In this population, sleep apnea has been frequently diagnosed, particularly in tetraplegic subjects. The true prevalence is likely to be considerably higher, since this study considered only previously diagnosed cases. Sleep apnea was associated with obesity and higher neurologic level, but not ASIA Impairment Scale. Medical comorbidities were more frequent in this group, and treatment acceptance was poor with higher level motor-complete injuries. Since the type of sleep apnea (central or obstructive) was not distinguished, we cannot comment on the prevalence and associations based on specific types of sleep apnea.

Kapur V, Blough DK, Sandblom RE, Hert R, de Maine JB, Sullivan SD, Psaty BM. · Department of Medicine, University of Washington, Seattle 98195, USA. · Sleep. · Pubmed #10505820 No free full text.

Abstract: Obstructive sleep apnea is an under-diagnosed, but common disorder with serious adverse consequences. Cost data from the year prior to the diagnosis of sleep-disordered breathing in a consecutive series of 238 cases were used to estimate the potential medical cost of undiagnosed sleep apnea and to determine the relationship between the severity of sleep-disordered breathing and the magnitude of medical costs. Among cases, mean annual medical cost prior to diagnosis was $2720 versus $1384 for age and gender matched controls (p<0.01). Regression analysis showed that the reciprocal of the apnea hypopnea index among cases was significantly related to log-transformed annual medical costs after adjusting for age, gender, and body mass index (p<0.05). We conclude that patients with undiagnosed sleep apnea had considerably higher medical costs than age and sex matched individuals and that the severity of sleep-disordered breathing was associated with the magnitude of medical costs. Using available data on the prevalence of undiagnosed moderate to severe sleep apnea in middle-aged adults, we estimate that untreated sleep apnea may cause $3.4 billion in additional medical costs in the U.S. Whether medical cost savings occur with treatment of sleep apnea remains to be determined.