Potential Role of Exogenous Melatonin Supplement in Delirium Prevention in Critically Ill Patients: A Double-Blind Randomized Pilot Study

Critically ill patients often suffer from disturbance of sleep-wake cycle and consequently delirium development, in intensive care units (ICU). In this study, we aimed to evaluate the effect of exogenous melatonin on delirium development and its related adverse sequelae in the subgroup of medical and surgical ICU patients. We performed a double-blind placebo-controlled randomized pilot study in adult patients admitted to the ICU. Recruited patients according to the considered inclusion criteria were randomized into treatment or placebo groups. Melatonin or placebo was administered in the first 24 h after admission, for 5 consecutive days. Incidence of delirium within 8 days of admission was reported as primary outcome in the different subgroups, and other pertinent clinical characteristics were evaluated as secondary outcomes. Out of the total of 172 patients assigned for the 2 study groups, 70 patients in placebo group and also 67 in melatonin group completed the study. We observed no therapeutic effect of melatonin on delirium prevention in ICU patients (percent of delirium in melatonin versus placebo group were 4.5% and 1.4% respectively). However, our findings indicated that melatonin might be more useful in preventing delirium development in medical ICU patients as compared to the surgical ICU patients. There were no intergroup differences in secondary outcomes with the follow-up ending on May 2016. Our findings suggested melatonin might be a potential option for prevention of delirium in medical ICU patients.