PURPOSE To evaluate the efficacy of short-term low-dose quetiapine for delirium prevention in critically ill patients.

METHODS In this prospective, a single-center, randomized, double-blind, placebo-controlled trial, adult patients who were admitted from July 2015 to July 2017 to a medical intensive care unit (ICU) of a tertiary teaching hospital affiliated to Seoul National University were included. Quetiapine (12.5 mg or 25 mg oral at night; N = 16) or placebo (N = 21) was administered according to randomization until ICU discharge or the 10th ICU day. The primary endpoint was the incidence of delirium within the first 10 ICU days. Secondary endpoints included the rate of positive Confusion Assessment Method for the ICU (CAM-ICU) (the number of positive CAM-ICU counts/the number of total CAM-ICU counts), delirium duration, successful extubation, and overall mortality.

RESULT The incidence of delirium during the 10 days after ICU admission was 46.7% (7/15) in the quetiapine group and 55.0% (11/20) in the placebo group (p = 0.442). In the quetiapine group, the rate of positive CAM-ICU was significantly lower than in the placebo group (14.4% vs. 37.4%, p = 0.048), delirium duration during the study period was significantly shorter (0.28 day vs. 1.83 days, p = 0.018), and more patients in the quetiapine than in the placebo group were weaned from mechanical ventilation successfully (84.6% vs. 47.1%, p = 0.040).

CONCLUSIONS Our study suggests that prophylactic use of low-dose quetiapine could be helpful for preventing delirium in critically ill patients. A further large-scale prospective study is needed.