Effect of obstructive sleep apnea on the sleep architecture in cirrhosis.

STUDY OBJECTIVES: Sleep disturbances in cirrhosis are assumed to be due to hepatic encephalopathy (HE). The interaction between cirrhosis, prior HE, and obstructive sleep apnea (OSA) has not been evaluated. We aimed to evaluate the additional effect of cirrhosis with and without prior HE on the sleep architecture and perceived sleep disturbances of OSA patients. METHODS: A case-control review of OSA patients who underwent polysomnography (PSG) in a liver-transplant center was performed. OSA patients with cirrhosis (with/without prior HE) were age-matched 1:1 with OSA patients without cirrhosis. Sleep quality, daytime sleepiness, sleep quality, and sleep architecture was compared between groups. RESULTS: Forty-nine OSA cirrhotic patients (age 57.4 ± 8.3 years, model for end-stage liver disease (MELD) 8.3 ± 5.4, 51% HCV, 20% prior HE) were age-matched 1:1 to OSA patients without cirrhosis. Apnea-hypopnea index, arousal index, sleep efficiency, daytime sleepiness, and effect of sleepiness on daily activities were similar between OSA patients with/ without cirrhosis. Sleep architecture, including %slow wave sleep (SWS), was also not different between the groups. MELD was positively correlated with time in early (N1) stage (r = 0.4, p = 0.03). All prior HE patients (n = 10) had a shift of the architecture towards early, non-restorative sleep (higher % [N2] stage [66 vs 52%, p = 0.005], lower % SWS [0 vs 29%, p = 0.02], lower REM latency [95 vs 151 minutes, p = 0.04]) compared to the rest. Alcoholic etiology was associated with higher latency to N1/N2 sleep, but no other effect on sleep architecture was seen. CONCLUSIONS: OSA can contribute to sleep disturbance in cirrhosis and should be considered in the differential of sleep disturbances in cirrhosis. Prior HE may synergize with OSA in worsening the sleep architecture.

A prospective multicenter study of competency metrics and educational interventions in the learning of bronchoscopy among new pulmonary fellows.

BACKGROUND: Learning medical procedures relies predominantly on the apprenticeship model, and competency is established based on the number of performed procedures. Our study aimed to establish bronchoscopy competency metrics based on performance and enhanced learning with educational interventions. METHODS: We conducted a prospective study of the acquisition of bronchoscopy skills and cognitive knowledge in two successive cohorts of new pulmonary fellows between July 5, 2006, and June 30, 2008. At prespecified milestones, validated tools were used for testing: the Bronchoscopy Skills and Tasks Assessment Tool (BSTAT), an objective evaluation of bronchoscopy skills with scores ranging from 0 to 24, and written multiple-choice questions examinations. The first cohort received training in bronchoscopy as per the standards set by each institution, whereas the second cohort received educational interventions, including training in simulation bronchoscopy and an online bronchoscopy curriculum. RESULTS: There was significant variation among study participants in bronchoscopy skills at their 50th bronchoscopy, the minimum number previously set to achieve competency in bronchoscopy. An educational intervention of incorporating simulation bronchoscopy enhanced the speed of acquisition of bronchoscopy skills, as shown by the statistically significant improvement in mean BSTAT scores for seven of the eight milestone bronchoscopies (P < .05). The online curriculum did not improve the performance on the written tests; however, compliance of the learners with the curriculum was low. CONCLUSIONS: Performance-based competency metrics can be used to evaluate bronchoscopy skills. Educational interventions, such as simulation-based training, accelerated the acquisition of bronchoscopy skills among first-year pulmonary fellows as assessed by a validated objective assessment tool.