The Efficacy of Oral Melatonin in Preventing Postoperative Delirium for Patients Undergoing Orthopedic Surgery Under General Anesthesia: A Randomized Controlled Trial

Delirium is a change in concentration that occurs acutely in association with a disturbed level of consciousness. Delirium is more common in orthopedic surgery patients than in general surgery patients. This study was conducted to determine the efficacy of administering melatonin preoperatively in patients undergoing orthopedic surgery to prevent postoperative delirium. This randomized controlled study included 36 patients who were scheduled for orthopedic surgery under general anesthesia. They were randomized into three groups: one that did not receive any drugs for sedation, another that received 7.5 mg of midazolam the night before the operation, and another that received another dose 90 min preoperatively. The last group received 5 mg of melatonin orally in the same manner. The patients had been assessed using the Memorial Delirium Assessment Scale postoperatively at 30, 60, and 90 min. Melatonin was shown to reduce delirium from 41.6% to 16.6% at 60 min, and the significant reduction was at 90 min (0%) when compared to both groups. Midazolam treatment reduced postoperative delirium. However, this change was statistically insignificant. Only melatonin was able to decrease the incidence of postoperative delirium significantly. Melatonin was found to be successful in decreasing postoperative delirium when administered preoperatively.