Efficacy of melatonin in decreasing the incidence of delirium in critically ill adults: a randomized controlled trial.

Objective: To determine whether enteral melatonin decreases the incidence of delirium in critically ill adults.

Methods: In this randomized controlled trial, adults were admitted to the intensive care unit and received either usual standard care alone (Control Group) or in combination with 3mg of enteral melatonin once a day at 9 PM (Melatonin Group). Concealment of allocation was done by serially numbered opaque sealed envelopes. The intensivist assessing delirium and the investigator performing the data analysis were blinded to the group allocation. The primary outcome was the incidence of delirium within 24 hours of the intensive care unit stay. The secondary outcomes were the incidence of delirium on Days 3 and 7, intensive care unit mortality, length of intensive care unit stay, duration of mechanical ventilation and Glasgow outcome score (at discharge).

Results: We included 108 patients in the final analysis, with 54 patients in each group. At 24 hours of intensive care unit stay, there was no difference in the incidence of delirium between Melatonin and Control Groups (29.6 versus 46.2%; RR = 0.6; 95%CI 0.38 - 1.05; p = 0.11). No secondary outcome showed a statistically significant difference.

Conclusion: Enteral melatonin 3mg is not more effective at decreasing the incidence of delirium than standard care is in critically ill adults.