RESUMO
PURPOSE: We evaluated the effects of melatonin used in the preoperative period for patients who had undergone surgical treatment of a zygomatic fracture. PATIENTS AND METHODS: A triple-blind, randomized clinical trial of 2 groups was conducted: the melatonin group (10 mg) and the placebo group. After allocation, 1 tablet of melatonin was used the night before and another tablet 2 hours before the start of surgery. Approximately 30 minutes before anesthetic induction, the following variables were evaluated: sleep quality, degree of sedation and anxiolysis using the Richmond Agitation-Sedation Scale, and the amount of opioid analgesic used intraoperatively. At the end of surgery, the time required for safe endotracheal extubation was evaluated. Next, a descriptive and inferential statistical analysis was performed. The margin of error considered was 5%. RESULTS: Of the 68 analyzed patients, 36 had been allocated to the melatonin group and 32 to the placebo group. In the sleep quality evaluation for the night before surgery, 61.1% of the melatonin group reported better or much better sleep than usual, and 100% of the placebo group reported worse sleep or sleep as usual (P < .001). Melatonin was no better than placebo in relation to anxiolysis (P > .05). The average final dose of the opioid was lower, and the difference was statistically significant, in the melatonin group (0.296 ± 0.036 µg/kg/min vs 0.372 ± 0.037 µg/kg/min in the placebo group). The interval required for safe endotracheal extubation was longer, and the difference was statistically significant, in the melatonin group (14.84 ± 1.8 minutes vs 12.72 ± 0.99 minutes in the placebo group). CONCLUSIONS: In the present study, melatonin was effective in improving sleep quality the night before surgery and in reducing intraoperative opioid consumption. An increase in the time required for safe endotracheal extubation was found in the melatonin group, and no improvement was seen in anxiolysis.
