The Efficacy of Melatonin and Clonidine in Preventing Emergence Delirium in the Elderly Undergoing Orthopedic Surgery, Neurosurgery, and General Surgery: A Placebo-controlled Randomized Clinical Trial

Background: Emergence delirium (ED) is a complication after surgeries due to general anesthesia. Objectives: This study aimed to evaluate the efficacy of melatonin and clonidine, which are hypothesized to have a curative effect on ED. Methods: This randomized, placebo-controlled, double-blind, three-way parallel clinical trial was performed in Imam Reza Hospital in Birjand, Iran in 2019 - 2020 who were selected using convenience sampling. The inclusion criteria were age > 65 years and preoperative Abbreviated Mental Test (AMT) score ≥ 8. The exclusion criteria were suffering from any chronic diseases. Participants were divided into 3 groups: Placebo, clonidine, and melatonin groups who received placebo, 100 μg clonidine, and 5 mg melatonin, respectively. A first dose was administered at bedtime before surgery, a second dose 90 minutes before the procedure. An AMT and Mini-mental State Examination (MMSE) were administered to determine ED. Results: This study included 150 patients with a mean and standard deviation of 74.6 ± 6.8 years. According to AMT and MMSE, there was no significant difference in the level of ED between groups on the first, second, and third days after surgery (P > 0.05). Emergence delirium levels in the clonidine and melatonin groups were lower than in the placebo group. According to AMT and MMSE, ED was not significantly correlated gender, age, and type of surgery. Emergence delirium was significantly associated with postoperative bleeding and electrolyte disturbance (P < 0.05). Conclusions: Melatonin and clonidine did not affect the occurrence of ED in the elderly undergoing surgery, but these medications could slightly reduce their occurrence.