Jacob Collen

Clinical and polysomnographic predictors of short-term continuous positive airway pressure compliance.

BACKGROUND Poor compliance and initial intolerance limit the effectiveness of continuous positive airway pressure (CPAP) in obstructive sleep apnea. Short-term compliance has been shown to predict long-term use. Unfortunately, few identified variables reliably predict initial CPAP tolerance and use. We sought to identify potential pretreatment variables that would predict short-term use of CPAP. METHODS We performed a retrospective review assessing short-term CPAP compliance after 4 to 6 weeks of treatment. Consecutive patients initiating CPAP therapy were included. Demographic and polysomnographic variables were correlated with objective measures of CPAP use. The average hours per night and percentage of nights of CPAP use were correlated with each variable. Variables were also associated with good vs poor compliance, which we defined as > 4 h per night > 70% of nights. RESULTS We included 400 consecutive patients (78% male; mean age, 47 +/- 8 years). Of the measured variables, only age (48 +/- 8 years vs 46 +/- 7 years, p = 0.02) and use of a sedative/hypnotic during CPAP titration (77% vs 57.6%, p < 0.0005) were associated with better compliance. Those receiving a sedative/hypnotic had longer sleep times (345 +/- 42 min vs 314 +/- 51 min, p < 0.0005) and greater sleep efficiency (84 +/- 9% vs 78 +/- 11%, p < 0.0005) during polysomnography. CPAP titrations were improved in those receiving sedative/hypnotics, achieving lower respiratory disturbance index on the final CPAP pressure (6 +/- 7 vs 10 +/- 11, p = 0.04). CONCLUSIONS Of the measured variables, only age and a one-time use of sedative/hypnotics during polysomnography correlated with greater short-term CPAP compliance. Hypnotics facilitated better quality CPAP titrations. Reliable predictors of short-term CPAP use could help identify measures to improve long-term compliance.

Sedative Use During Continuous Positive Airway Pressure Titration Improves Subsequent Compliance A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND The initial experience with continuous positive airway pressure (CPAP) may predict subsequent compliance. In a retrospective study, we found that premedication with nonbenzodiazepine sedative-hypnotic agents during CPAP titration polysomnography independently predicted short-term compliance. To validate these findings, we conducted a prospective clinical trial to assess whether premedication with eszopiclone prior to CPAP titration would improve short-term CPAP compliance. METHODS Subjects in this randomized, double-blind, placebo-controlled trial received 3 mg of eszopiclone or matching placebo prior to undergoing CPAP titration polysomnography. We compared the quality of CPAP titrations and objective measures of compliance during the first 4 to 6 weeks of therapy between the two groups. RESULTS We enrolled 117 subjects, and 98 subjects completed the protocol (eszopiclone, 50 subjects; placebo, 48 subjects). Other than there being more women in the eszopiclone group, the groups were similar at baseline. Compared with placebo, premedication with eszopiclone significantly improved mean (+/- SD) sleep efficiency (87.8 +/- 5.8% vs 80.1 +/- 10.5%, respectively; p = 0.002) and mean total sleep time (350.9 +/- 33.6 min vs 319.7 +/- 48.7 min, respectively; p = 0.007). A trend toward improved sleep latency (19.4 +/- 16.1 min vs 31.8 +/- 30.4 min, respectively; p = 0.08) and the number of residual obstructive events observed at the final CPAP pressure (6.4 +/- 7 events/h vs 12.8 +/- 14.6 events/h, respectively; p = 0.08) during polysomnography was found. Eszopiclone significantly improved CPAP compliance. Among subjects premedicated with eszopiclone, CPAP was used on a higher percentage of nights (75.9 +/- 20.0% vs 60.1 +/- 24.3%, respectively; p = 0.005) and for more hours per night (4.8 +/- 1.5 h vs 3.9 +/- 1.8 h, respectively; p = 0.03). CONCLUSIONS Premedication with eszopiclone on the night of CPAP titration improved the quality of CPAP titration and led to significantly greater short-term compliance. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT00507117.

Discordance in Spirometric Interpretations Using Three Commonly Used Reference Equations vs National Health and Nutrition Examination Study III

BACKGROUND Spirometry plays an essential role in the diagnosis and management of pulmonary diseases. The accurate interpretation of spirometric data depends on comparison to a reference population to identify abnormalities in ventilatory function. National guidelines recommended the use of the National Health and Nutrition Examination Study (NHANES) III data set as the preferred reference population for those persons 8 to 80 years of age in the United States. OBJECTIVES To determine the effect of using NHANES III reference equations, compared to those of Crapo et al (Crapo), Knudson et al (Knudson), or Morris et al (Morris), on spirometric interpretations in non-Hispanic white patients. METHODS We conducted a cross-sectional study of all white patients undergoing spirometry testing at our hospital from January 2000 through May 2007. Patients were classified as normal, restricted, obstructed, or mixed, based on the American Thoracic Society (ATS)/European Respiratory Society (ERS) guidelines, using the Crapo, Knudson, Morris, and NHANES III prediction equations. Differences in the classifications based on the reference data set were evaluated. RESULTS At total of 8,733 subjects (62.4% male subjects) were identified, with a mean age of 53 years. Discordance was most common when the results from prediction equations by Knudson and Morris were compared to those of NHANES III (45.5% and 35.3%, respectively). Diagnostic recategorizations occurred less frequently when the prediction equations by Crapo were compared with those of NHANES III (15.9%). Relative to NHANES III, the prediction equations by Knudson, Crapo, and Morris tend to overclassify obstruction and underclassify restriction. CONCLUSIONS There is significant discordance between the prediction equations put forth by Crapo, Knudson, Morris, and the NHANES III. Our data suggest that the diagnostic reclassification of many patients undergoing pulmonary function testing will occur when ATS/ERS guidelines are implemented. Pulmonologists and other physicians interpreting spirometry need to be aware of the presence and nature of these changes.

Original ResearchSleep MedicineSedative Use During Continuous Positive Airway Pressure Titration Improves Subsequent Compliance: A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND The initial experience with continuous positive airway pressure (CPAP) may predict subsequent compliance. In a retrospective study, we found that premedication with nonbenzodiazepine sedative-hypnotic agents during CPAP titration polysomnography independently predicted short-term compliance. To validate these findings, we conducted a prospective clinical trial to assess whether premedication with eszopiclone prior to CPAP titration would improve short-term CPAP compliance. METHODS Subjects in this randomized, double-blind, placebo-controlled trial received 3 mg of eszopiclone or matching placebo prior to undergoing CPAP titration polysomnography. We compared the quality of CPAP titrations and objective measures of compliance during the first 4 to 6 weeks of therapy between the two groups. RESULTS We enrolled 117 subjects, and 98 subjects completed the protocol (eszopiclone, 50 subjects; placebo, 48 subjects). Other than there being more women in the eszopiclone group, the groups were similar at baseline. Compared with placebo, premedication with eszopiclone significantly improved mean (+/- SD) sleep efficiency (87.8 +/- 5.8% vs 80.1 +/- 10.5%, respectively; p = 0.002) and mean total sleep time (350.9 +/- 33.6 min vs 319.7 +/- 48.7 min, respectively; p = 0.007). A trend toward improved sleep latency (19.4 +/- 16.1 min vs 31.8 +/- 30.4 min, respectively; p = 0.08) and the number of residual obstructive events observed at the final CPAP pressure (6.4 +/- 7 events/h vs 12.8 +/- 14.6 events/h, respectively; p = 0.08) during polysomnography was found. Eszopiclone significantly improved CPAP compliance. Among subjects premedicated with eszopiclone, CPAP was used on a higher percentage of nights (75.9 +/- 20.0% vs 60.1 +/- 24.3%, respectively; p = 0.005) and for more hours per night (4.8 +/- 1.5 h vs 3.9 +/- 1.8 h, respectively; p = 0.03). CONCLUSIONS Premedication with eszopiclone on the night of CPAP titration improved the quality of CPAP titration and led to significantly greater short-term compliance. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT00507117.

The impact of posttraumatic stress disorder on CPAP adherence in patients with obstructive sleep apnea.

INTRODUCTION Obstructive sleep apnea (OSA) is a common comorbid condition in patients with posttraumatic stress disorder (PTSD); insufficiently treated OSA may adversely impact outcomes. Sleep fragmentation and insomnia are common in PTSD and may impair CPAP adherence. We sought to determine the impact of combat-related PTSD on CPAP adherence in soldiers. METHODS Retrospective case-control study. Objective measures of CPAP use were compared between OSA patients with and without PTSD. Groups were matched for age, BMI, and apnea-hypopnea index (AHI). RESULTS We included 90 patients (45 Control, 45 PTSD). Among the cohort, mean age was 39.9 ± 11.2, mean BMI 27.9 ± 8.0, mean ESS 13.6 ± 5.7, and mean AHI 28.2 ± 22.4. There was a trend towards a higher rate of comorbid insomnia among patients with PTSD (25.8% vs. 11.1%, p = 0.10). PTSD was associated with significantly less use of CPAP. Specifically, CPAP was used on 61.4% ± 22.2% of nights in PTSD patients compared with 76.8% ± 16.4% in patients without PTSD (p = 0.001). Mean nightly use of CPAP was 3.4 ± 1.2 h in the PTSD group compared with 4.7 ± 2.2 h among controls (p < 0.001). Regular use of CPAP (> 4 h per night for > 70% of nights) was also lower among PTSD patients (25.2% vs. 58.3%, p = 0.01). CONCLUSION Among soldiers with OSA, comorbid PTSD was associated with significantly decreased CPAP adherence. Given the potential for adverse clinical outcomes, resolution of poor sleep quality should be prioritized in the treatment of PTSD and potential barriers to CPAP adherence should be overcome in patients with comorbid OSA.

Ethical Practice Under Fire: Deployed Physicians in the Global War on Terrorism

The Global War on Terrorism brings significant ethical challenges for military physicians. From Abu Ghraib to Guantanamo Bay, the actions of health care providers have come under considerable scrutiny. Military providers have dual roles as military officers and medical professionals, which have the potential to come into conflict. Often they are inadequately prepared to manage this conflict. We review pertinent historical precedents, applicable laws, ethical guidelines, and military regulations. We also present examples of ethical challenges deployed clinicians have faced and their ethical solution. Finally, we propose a practical strategy to educate physicians on how to manage complex ethical dilemmas in war time settings.

Postoperative CPAP use impacts long-term weight loss following bariatric surgery.

INTRODUCTION Obstructive sleep apnea (OSA) is common among bariatric surgery candidates. After surgical weight loss, OSA frequently persists and untreated OSA can lead to weight gain. Long-term continuous positive airway pressure (CPAP) adherence is unclear and poor adherence may worsen weight loss outcomes. We sought to determine the impact of CPAP use on long-term weight-loss outcomes in a cohort of bariatric patients. METHODS Long-term observational study of bariatric surgery patients with OSA. Patients were evaluated with polysomnography preoperatively and one-year postoperatively. The cohort was again evaluated a mean of 7.2 years later to determine the relationship between long-term CPAP use and subsequent regain of weight. RESULTS Twenty-four consecutive patients (aged 48.5 ± 9.4 years at time of surgery; 73% female) were included in the initial assessment, and long-term outcome data were available on 22 subjects. Persistent OSA was documented in 21 of 22 subjects (95%) one year postoperatively. Final evaluation occurred 7.2 ± 2.3 years following surgery. Weight (213.3 ± 39.1 to 235.3 ± 47.1 lb, p = 0.10) and BMI (32.5 ± 5.4 to 37.3 ± 8.2 kg/m(2), p = 0.03) increased in most (n = 19, 86.4%) from postoperative to final evaluation. CPAP use declined from 83.3% (preoperatively) to 38.1% (one year) and to 23.8% (final evaluation). BMI increased among those not using CPAP at long-term follow-up compared to those with continued CPAP use (6.8% v -1.8%, p = 0.05). CONCLUSIONS In our cohort of bariatric patients with OSA, long-term adherence to CPAP therapy was poor, and non-adherence was associated with weight gain. Ongoing follow-up of OSA in this population may help to preserve initial achievements after surgical weight loss.

A Comparative Analysis of Sleep Disordered Breathing in Active Duty Service Members with and without Combat-Related Posttraumatic Stress Disorder.

STUDY OBJECTIVES Posttraumatic stress disorder (PTSD) and obstructive sleep apnea (OSA) are frequently co-occurring illnesses. The purpose of this study was to determine whether comorbid PTSD/OSA is associated with increased PTSD symptoms or decreased OSA severity compared to PTSD or OSA alone in recently deployed Active Duty Service Members (ADSM). METHODS Cross-sectional observational study of ADSM who returned from combat within 24 months. Participants underwent an attended diagnostic polysomnogram and were assessed for PTSD, depression, combat exposure severity, sleepiness, and sleep quality with validated clinical instruments. RESULTS Our study included 109 military personnel who returned from a combat deployment within 24 months with a mean age of 34.3 ± 8.23 and BMI of 30.8 ± 3.99. Twenty-four participants had PTSD/OSA, 68 had OSA, and 17 had PTSD. Mean PTSD Checklist- Military Version (PCL-M) scores were 62.0 ± 8.95, 60.5 ± 4.73, and 32.5 ± 8.95 in PTSD/OSA, PTSD, and OSA, respectively. The mean AHI was 16.9 ± 15.0, 18.9 ± 17.0, and 1.73 ± 1.3 for those with PTSD/OSA, OSA, and PTSD. PTSD symptoms and OSA severity in military personnel with comorbid PTSD/OSA were not significantly different from those with PTSD or OSA alone. On multivariate analysis, BMI was a significant predictor of OSA (OR, 1.21; 95% CI, 1.04-1.44) and age trended towards significance. Depression, but not OSA severity, was associated with PTSD symptoms. CONCLUSIONS Following recent combat exposure, comorbid PTSD/OSA is not associated with increased PTSD symptoms or decreased severity of OSA. Early evaluation after traumatic exposure for comorbid OSA is indicated in PTSD patients with sleep complaints given the high co-occurrence and adverse clinical implications.

Venous thromboembolism prophylaxis for patients receiving regional anesthesia following injury in Iraq and Afghanistan.

BACKGROUND Soldiers with combat-related traumatic injury are at high risk for venous thromboembolism (VTE) and often require regional anesthesia (RA) for pain control. We evaluated whether the recommended reduction in chemoprophylaxis in the presence of RA increases VTE rates. METHODS We collected data each hospital day for all soldiers admitted to the Walter Reed Army Medical Center following injury in Iraq or Afghanistan. We analyzed thromboprophylaxis and RA rates and assessed risk factors for VTE. We separated outcomes by whether RA was central neuraxial (cNAB) or peripheral blockade. RESULTS Among 1,259 patients, 323 received RA for a median of 12 days (5–27 days). Those with RA were younger and more likely to have been injured in combat or by an improvised explosive device. They also received more packed red blood cell transfusions and had longer admissions. Patients with RA spent a greater percentage of days on enoxaparin 40 mg daily compared with those without RA (34.4% vs. 22.0%, p < 0.001) and more hospital days without any chemoprophylaxis (2.0 [1.0–6.0] vs. 1.0 [0.0–3.0], p < 0.001). Patients with cNAB were less likely to be placed on enoxaparin 30 mg twice daily. Patients with RA in place had mechanical prophylaxis ordered at the same rate as those without RA. Neither the presence of any RA nor cNAB specifically was associated with an increased risk for VTE. No bleeding or neurologic complications occurred in those receiving RA. CONCLUSION Despite changes to chemoprophylaxis, soldiers wounded in combat who receive RA are not at increased risk for VTE. LEVEL OF EVIDENCE Therapeutic study, level III.

Racial discordance in spirometry comparing four commonly used reference equations to the National Health and Nutrition Examination Study III

Diagnosing lung function abnormalities requires application of the appropriate reference equation for a given patient population. Current guidelines recommend the National Health and Examination Study III data set for evaluating patients in the United States. In Caucasian patients, relying on older reference equations, as opposed to those derived from the NHANES III data set, will often result in a different interpretation of a patients spirometry. The present study assessed whether similar discordance would occur in African-American patients. A cross-sectional analysis of African-American patients undergoing spirometry testing at our hospital was performed. Patients were classified as normal, restricted, obstructed or mixed based upon the ATS/ERS guidelines, using Crapo, Knudson, Morris, Glindmeyer, and NHANES III prediction equations. Differences in classification were evaluated. 4463 subjects were identified, with a mean age of 49.6. Discordance in interpretation was most common when results from prediction equations by Morris, Knudson, and Glindmeyer were compared to NHANES III (24.6%, 26.4%, and 20.1%, respectively). Discordance was less common when comparing Crapo to NHANES III (12.8%). There was a tendency for Knudson, Morris and Glindmeyer to under classify restriction, and for Crapo, Morris, and Glindmeyer to over classify obstruction. There is significant discordance in interpretation when spirometry for African-American patients is referenced to equations published by Crapo, Morris, Knudson, and Glindmeyer, compared to NHANES III.