Aaron B. Holley

Efficacy of an Adjustable Oral Appliance and Comparison With Continuous Positive Airway Pressure for the Treatment of Obstructive Sleep Apnea Syndrome

BACKGROUND We sought to establish the efficacy of an adjustable oral appliance (aOA) in the largest patient population studied to date, to our knowledge, and to provide a comparison with continuous positive airway pressure (CPAP). METHODS We conducted a retrospective analysis of patients using an aOA. Results of overnight polysomnography with aOA titration were evaluated and compared with CPAP. Predictors of a successful aOA titration were determined using a multivariate logistic regression model. RESULTS A total of 497 patients were given an aOA during the specified time period. The aOA reduced the mean apnea-hypopnea index (AHI) to 8.4 ± 11.4, and 70.3%, 47.6%, and 41.4% of patients with mild, moderate, and severe disease achieved an AHI < 5, respectively. Patients using an aOA decreased their mean Epworth Sleepiness Score by 2.71 (95% CI, 2.3-3.2; P < .001) at follow-up. CPAP improved the AHI by -3.43 (95% CI, 1.88-4.99; P < .001) when compared with an aOA, but when adjusted for severity of disease, this difference only reached significance for patients with severe disease (-5.88 [95% CI, -8.95 to -2.82; P < .001]). However, 70.1% of all patients achieved an AHI < 5 using CPAP compared with 51.6% for the aOA (P < .001). On multivariate analysis, baseline AHI was a significant predictor of achieving an AHI < 5 on aOA titration, and age showed a trend toward significance. CONCLUSIONS In comparison with past reports, more patients in our study achieved an AHI < 5 using an aOA. The aOA is comparable to CPAP for patients with mild disease, whereas CPAP is superior for patients with moderate to severe disease. A lower AHI was the only predictor of a successful aOA titration.

Validation of the International Medical Prevention Registry on Venous Thromboembolism Bleeding Risk Score

Objectives Recent guidelines recommend assessing medical inpatients for bleeding risk prior to providing chemical prophylaxis for venous thromboembolism (VTE). The International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) bleeding risk score (BRS) was derived from a well defined population of medical inpatients but it has not been externally validated. We sought to externally validate the IMPROVE BRS. Methods We prospectively collected characteristics on admission and VTE prophylaxis data each hospital day on all patients admitted for a medical illness to the Walter Reed Army Medical Center (WRAMC) over an 18 month period. We calculated the IMPROVE BRS for each patient using admission data and reviewed medical records to identify bleeding events. Results From September 2009 through March 2011 there were 1668 inpatients who met the IMPROVE inclusion criteria. Bleeding events occurred during 45 (2.7%) separate admissions; 31 (1.9%) events were major and 14 (0.8%) were non-major but clinically relevant. 256 (20.7%) patients had an IMPROVE BRS ≥ 7.0. Kaplan-Meier curves showed a higher cumulative incidence of major (p=0.02) and clinically important (major plus clinically relevant non-major) (p=0.06) bleeding within 14 days in patients with an IMPROVE BRS ≥ 7.0. An IMPROVE BRS ≥ 7.0 was associated with major bleeding in Cox-regression analysis adjusted for administration of chemical prophylaxis (OR 2.6, 95% CI: 1.1-5.9; p=0.03); there was a trend toward significant association with clinically important bleeding (OR 1.9, 95% CI: 0.9-3.7; p=0.07). Conclusions The IMPROVE BRS calculated at admission predicts major bleeding in medical inpatients. This model may help assess relative risks of bleeding and VTE before chemoprophylaxis is administered.BACKGROUND Recent guidelines recommend assessing medical inpatients for bleeding risk prior to providing chemical prophylaxis for VTE. The International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) bleeding risk score (BRS) was derived from a well-defined population of medical inpatients but it has not been validated externally. We sought to externally validate the IMPROVE BRS. METHODS We prospectively collected characteristics on admission and VTE prophylaxis data each hospital day for all patients admitted for a medical illness to the Walter Reed Army Medical Center over an 18-month period. We calculated the IMPROVE BRS for each patient using admission data and reviewed medical records to identify bleeding events. RESULTS From September 2009 through March 2011, 1,668 inpatients met the IMPROVE inclusion criteria. Bleeding events occurred during 45 separate admissions (2.7%); 31 events (1.9%) were major and 14 (0.8%) were nonmajor but clinically relevant. Two hundred fifty-six patients (20.7%) had an IMPROVE BRS ≥ 7.0. Kaplan-Meier curves showed a higher cumulative incidence of major (P = .02) and clinically important (major plus clinically relevant nonmajor) (P = .06) bleeding within 14 days in patients with an IMPROVE BRS ≥ 7.0. An IMPROVE BRS ≥ 7.0 was associated with major bleeding in Cox-regression analysis adjusted for administration of chemical prophylaxis (OR, 2.6; 95% CI, 1.1-5.9; P = .03); there was a trend toward a significant association with clinically important bleeding (OR, 1.9; 95% CI, 0.9-3.7; P = .07). CONCLUSIONS The IMPROVE BRS calculated at admission predicts major bleeding in medical inpatients. This model may help assess the relative risks of bleeding and VTE before chemoprophylaxis is administered.

Eucapnic Voluntary Hyperventilation Is Superior to Methacholine Challenge Testing for Detecting Airway Hyperreactivity in Nonathletes

Introduction. Response to eucapnic voluntary hyperventilation (EVH) has not been compared with methacholine challenge testing (MCCT) in nonathletes being evaluated for dyspnea on exertion. Objective. To determine the airway response to EVH and MCCT in a population of nonathletes who exercise regularly but have symptoms with exertion. Methods. We reviewed records for all patients with exercise symptoms who underwent both EVH and MCCT. Presenting symptoms, comorbid diseases, and results of bronchoprovocation (BP) testing were recorded. This study was approved by the institutional review board at our hospital. Results. A total of 131 patients (mean age 32.3 ± 11.6, body mass index (BMI) 27.1 ± 4.7 kg/m2, 59.5% male) had an EVH, MCCT, and clinical evaluation performed. Overall, 37 (28.2%) patients had positive BP testing and met criteria for exercise-induced bronchoconstriction (EIB). There were 32 (24.4%) patients with a positive EVH, compared with only 11 patients with a positive MCCT (8.4%). There were 26 patients (19.8%) who had a positive EVH but a negative MCCT, and correlation between the two tests was poor to moderate (r = 0.11–0.57). A complaint of chest pain and younger age were independent predictors for a positive EVH, whereas a history of tobacco use and a decreased FEV1/FVC (forced expiratory volume in 1 s/forced vital capacity) predicted a positive MCCT. A previous diagnosis of asthma was an independent predictor for a response to either test. Discussion. In a population of nonathletes who exercise regularly and have symptoms with exertion, EIB is common. Correlation between EVH and MCCT in this population is poor, and although the tests are somewhat complementary, a large percentage of patients had a negative MCCT but a positive EVH. Conclusions. EIB is common in nonathletes with exercise-induced symptoms, and EVH is the preferred test for this population. Clinical implications. EIB is common in nonathletes who exercise regularly. In this population, MCCT will miss most patients with EIB, and MCCT and EVH show only poor-to-moderate correlation. Capsule summary: EVH has not been compared with MCCT in nonathletes without a diagnosis of asthma. Our study shows that the two tests are complementary in this population, but EVH is positive more often.

A mobile, web-based system can improve positive airway pressure adherence

SleepMapper is a mobile, web‐based system that allows patients to self‐monitor their positive airway pressure therapy, and provides feedback and education in real time. In addition to the usual, comprehensive support provided at our clinic, we gave the SleepMapper to 30 patients initiating positive airway pressure. They were compared with patients initiating positive airway pressure at our clinic without SleepMapper (controls) to determine whether SleepMapper affected adherence. A total of 61 patients had polysomnographic and adherence data analysed, 30 were given SleepMapper and 31 received our standard of care. The two groups were well matched at baseline to include no significant differences in age, apnea–hypopnea index, percentage receiving split‐night polysomnographs and starting pressures. Patients in the control group received significantly more non‐benzodiazepine sedative hypnotics the night of their polysomnography and during positive airway pressure initiation. At 11 weeks, patients in the SleepMapper group had a greater percentage of nights with any use (78.0 ± 22.0 versus 55.5 ± 24.0%; P < 0.001) and >4 h positive airway pressure use (78.0 ± 22.0 versus 55.5 ± 24.0%; P = 0.02). There was a trend toward more patients in the SleepMapper group achieving >4 h of use for at least 70% of nights [9/30 (30%) versus 3/31 (9.7%); P = 0.06]. In multivariate linear regression, the SleepMapper remained significantly associated with percentage of nights >4 h positive airway pressure use (β coefficient = 0.18; P = 0.02). Added to our usual, comprehensive programme to maximize positive airway pressure adherence in new users, the SleepMapper was independently associated with an 18% increase in nights >4 h of use.

Diagnosis of Obstructive Sleep Apnea in Adults

My candle burns at both ends; It will not last the night; But ah, my foes, and oh, my friends It gives a lovely light. Edna St. Vincent Millay TO THE EDITOR: We read with concern the ACP clinical guideline about the diagnosis of OSA (1). This guideline offers PSG as a solitary tool for sleep-related symptoms; the guidelines broad application could result in unnecessary testing and treatment. Polysomnography performed with current technologies and scored using the criteria recommended by the AASM in 2012 will yield an average apneahypopnea index that is 3-fold higher than that obtained with the equipment and scoring criteria available at the time of most of the studies cited to support this guideline. Flow changes are currently graded using a pressure-transduced air flow monitorwhich is far more sensitive than the thermistor used in prior studiesand the new AASM guideline does not require oxygen desaturation to be present for a breathing event to be scored (2). In fact, a recent trial showed that the prevalence of an apneahypopnea index of 5 or more events per hour using the current criteria was 94.6% in a population with a mild-moderate pretest probability of OSA (3). This condition exists on a spectrum, and apneahypopnea index cutoffs are largely arbitrary. Given the changes in diagnosis, are we measuring clinically meaningful disease? What are the costs of overdiagnosis? Furthermore, the term unexplained sleepiness (which is pivotal in the guidelines first recommendation) is meaningful only when clinicians thoroughly understand the causes of sleepiness. The average physician receives approximately 2 hours of formal medical education on the evaluation of sleep disorders (4). This guideline fails to acknowledge that behaviorally induced insufficient sleep, insomnia, mood disorders, the restless legs syndrome, and many other problems cannot be measured by PSG or treated with continuous positive airway pressure. We know from survey data that the average person in the United States effectively burns the candle at both ends, obtaining 6 hours and 40 minutes of sleep on the average workday (5). Recommending PSG for every patient whose sleepiness is unexplainedwithout also recommending qualitative and quantitative assessment of sleep durationis ill-advised. We suggest that the ACP develop a comprehensive sleepsymptom guideline that encourages a more holistic evaluation of the patient who presents with sleepiness and focuses more attention on the limitations of PSG.

Will minimizing dyspnea impact sleep quality

In their article published in this issue of Sleep and Breathing, Nunes et al. present actigraphy data on COPD patients and provide a comparison to controls. It is well known that COPD patients often report poor-quality sleep [1–3]. Therefore, it is not necessarily surprising that they found worse sleep on actigraphy in their COPD patients. There are two findings that deserve mention though. One is the absence of correlation between actigraphy findings and subjective measures of sleep quality (Pittsburgh Sleep Quality Index, PSQI; Epworth Sleepiness Scale, ESS). This lack of correlation suggests actigraphy reveals decrements in sleep that might otherwise go undetected. Of course, actigraphy should only be ordered if it has prognostic or therapeutic value that is independent of subjective measures of sleep quality. This leads to the second finding, the independent association between dyspnea and sleep parameters measured on actigraphy (sleep efficiency and total sleep time). Because this is a crosssectional study, the direction of causality, and for that matter causality itself, cannot be definitively established. For example, patients with worse dyspnea are more likely to be on medication, and some medications have been associated with sleep fragmentation. [4]. Dyspnea may simply be a surrogate marker for more medication use, rather than an actual cause of disrupted sleep. Although patient medications are mentioned, there are no data on correlation with actigraphy, PSQI, or ESS. COPD severity is another potential confounder that is not accounted for in their model. If there is causality though, either poor sleep worsens dyspnea or, as the authors suggest, dyspnea adversely affects sleep. In this case, actigraphy provides important information that may not be captured by subjective questionnaires like the PSQI. It may prove to be a valuable, non-invasive tool to help improve symptoms in patients with COPD and poorly controlled dyspnea.