Night sleep disruption related to delirium incidence in critically ill patients

Abstract

Background: Delirium is common in the intensive care unit (ICU). Many critically ill patients treated in the ICU experience sleep disruption. Disrupted sleep in the ICU has been proposed as a potential risk factor for delirium, but the evidence is sparse. This study was undertaken to identify the sleep status for the development of delirium in non-sedated critically ill patients Methods: This prospective study was conducted in medical ICU of a tertiary referral hospital. Polysomnography recording was performed over 24 hour to assess the quantity and quality of sleep. Delirium was measured daily using the Confusion Assessment Method for the ICU. Results: Total 20 patients were enrolled. Median total sleep time was 03:43 (hh:mm, IQR: 00:49 - 06:10). The majority of sleep was stage 1 (median 03:02 [00:47 - 04:34]) with scant stage 2 (median 00:00 [00:00 - 00:46]), REM (median 00:00 [00:00 - 00:15]) and absent stage 3. Delirium was developed in 4 patients (20%). In multivariable analysis, the duration of ICU stay more than 5 days was independently associated with delirium incidence (P=0.042). We also found that patients who stayed more than 5 days in ICU showed significant reduction in night sleep time compared to patients who stayed less than 5 days (00:42 ± 0:46 vs 2:04 ± 1:25, P=0.012), despite of similar total sleep time. Conclusions: The long duration of ICU stay disrupted night sleep which might contribute to the development of delirium in critically ill patients.