The effects of a mid-day nap on the neurocognitive performance of first-year medical residents: a controlled interventional pilot study.

PURPOSE: Despite shorter duty hours, fatigue remains a problem among medical residents. The authors tested the effect of a short, mid-day nap on the cognitive functioning and alertness of first-year internal medicine (IM) residents during normal duty hours. METHOD: This was a controlled, interventional study performed between July 2008 and April 2010. The authors recruited a nap group of 18 residents and a rest (control) group of 11 residents. Investigators connected all participants to an ambulatory sleep monitor before the beginning of their shifts in order to monitor rolling eye movements, a proxy for attention failures. At mid-day, both groups took Conner's Continuous Performance Test (CPT II) to evaluate their cognitive functioning and then were placed in a reclining chair designed for napping. The authors instructed nap group residents to nap for up to 20 minutes and chatted with control group residents to prevent them from napping. All residents took the CPT II again immediately after the intervention. Residents' attention failures were recorded until the end of the workday. The authors compared the mean outcome parameters of the two groups through analysis of variance, using effect-of-treatment and baseline covariates. RESULTS: Nap group participants slept a mean of 8.4±3.0 minutes. Compared with controls whose cognitive functioning and number of attention failures did not change from morning to afternoon, the nap group's cognitive functioning improved and their number of attention failures decreased. CONCLUSIONS: A short, mid-day nap can improve cognitive functioning and alertness among first-year IM residents.

Inspiratory airflow dynamics during sleep in veterans with Gulf War illness: a controlled study.

PURPOSE: To determine whether veterans with Gulf War Illness (GWI) are distinguished by sleep-disordered breathing, we compared inspiratory airflow dynamics during sleep between veterans with GWI and asymptomatic veterans of the first Gulf War. METHODS: We recruited 18 male veterans with GWI and 11 asymptomatic male veterans of the first Gulf War by advertisement. The two samples were matched for age and body mass index. Each participant underwent a first full-night polysomnogram (PSG) while sleeping supine using standard clinical monitoring of sleep and breathing. A second PSG was performed measuring airflow with a pneumotachograph in series with a nasal mask and respiratory effort with a supraglottic pressure (Psg) catheter to assess the presence of inspiratory airflow limitation during supine N2 sleep. We determined the prevalence of flow-limited breaths by sampling continuous N2 sleep and plotting inspiratory flow against Psg for each breath in the sample. We expressed the prevalence of flow-limited breaths as their percentage in the sample. RESULTS: Compared to controls, veterans with GWI had an increased frequency of arousals related to apneas, hypopneas, and mild inspiratory airflow limitation. During supine N2 sleep, veterans with GWI had 96 ± 5% (mean ± SD) of their breaths flow-limited while controls had 36 ± 25% of their breaths flow limited (p < 0.0001). CONCLUSIONS: Veterans with GWI experience sleep-disordered breathing that may distinguish them from asymptomatic veterans of the first Gulf War.