Document Type : Original Article


1 Anesthesiology, Critical care, and Pain management Research center, Hormozgan University of Medical Sciences, Bandar Abbas, IRAN

2 Anesthesiology, Critical Care and Pain Management Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Iran.


Introduction: Melatonin is synthesized from the tryptophan amino acid in the pineal gland. Its role in Sleep was defined previously. Several studies have shown the effect of melatonin on postoperative pain and sedation. The aim of this study was to evaluate the effect of melatonin on postoperative pain in patients undergoing an appendectomy.
Methods: In a double-blind clinical trial, 64 patients aged 18-80 years with an ASA Ⅰ-Ⅱ anesthesia class who had been candidates for appendectomy with general anesthesia were enrolled. Patients were randomly divided into two groups’ melatonin and placebo (each group was 32). The first group received 6 mg of oral melatonin one hour before while the second group received a placebo. Before surgery and during the hours 2, 12, and 24 hours after surgery, patients' pain was measured based on the VAS. The patients' sedation was measured according to the Ramsay score and rescue analgesia was measured at the above time points. To analyze the data, SPSS software was used and the significance level was considered as P-value<0.05.
Results: The results of our study showed that pain levels in the melatonin group were lower in the 2nd, 12, and 24th hours after the surgery of the appendectomy than in the placebo group. Sedation rates were not significantly different between the two groups. The analgesic consumption was lower in the Melatonin group than in the placebo group.
Conclusion: Melatonin has a positive effect on the degree of pain (VAS) after an appendectomy.


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