Featured Articles from November 2015

Preoperative Sleep Disruption and Postoperative Delirium

Delirium and sleep disruption are both common in the older patients who are hospitalized. Sleep disruption, including changes in sleep patterns and architecture, and decreased quality of sleep are commonly observed in older subjects. In a preliminary study, we monitored sleep in 50 patients (mean age 66 ± 11 years) with wrist actigraphy for 3 days before and 3 days after surgery. Postoperative delirium was measured using the Confusion Assessment Method. By actigraphy, the preoperative sleep for patients who ultimately developed postoperative delirium showed disruption beginning 2 days before surgery. The incidence of postoperative delirium observed during any of the 3 postoperative days was 14%. For the 7 patients with postoperative delirium, wake after sleep onset (WASO) as a percentage of total sleep time was significantly higher (44% ± 22%) during the night before surgery compared to the patients without delirium (21% ± 20%, p = 0.012). Patients with WASO < 10% did not experience postoperative delirium. We concluded in this pilot study that sleep disruption was more severe in the days just before surgery in the patients who experienced postoperative delirium. Our novel finding of sleep disruption beginning before surgery provides important guidance for clinical assessment and interventions to improve sleep before surgery. Specifically, future work should target the etiology of nocturnal wake time in the period immediately before the planned surgery.