Effect of oral melatonin on patients' anxiety scores and dose requirement of propofol during bispectral index-guided induction of general anesthesia

Background: Management of preoperative anxiety in surgical patients is usually required for better perioperative hemodynamics and patient management. Various pharmacological and nonpharmacological entities have been used for the management of anxiety. The aim of this study was to analyze the effect of oral melatonin on patient anxiety scores and dose requirement of propofol using bispectral index (BIS)-guided induction of general anesthesia. Materials and Methods: Sixty patients of American Society of Anesthesiologists physical Status I and II between 18 and 45 years of age scheduled to undergo elective surgery of more than 30 min participated in this study. Patients were divided into control and melatonin groups, comprising 30 patients each. Group M patients received two melatonin tablets (3 mg each) and Group C patients received two placebo tablets 120 min before induction. Anxiety scores using visual analog scale-anxiety at baseline and 120 min, mean dose requirement of propofol, time to attain BIS value of 55 in seconds, and hemodynamic parameters were studied in-between the groups. Results: There were significant differences between two groups in anxiety scores 120 min after drug dosage (P = 0.0013) with Group M patients with reduced levels of anxiety, and mean requirement of propofol in Group C (104.67 +/- 16.34 mg) was found to be statistically significantly higher than Group M (70.67 +/- 16.39 mg), P < 0.001. Hemodynamic parameters in terms of heart rate and mean arterial blood pressures were better for Group M in comparison to Group C. Conclusion: 6 mg of melatonin 120 min before elective surgery can allay anxiety in patients along with reduced dose requirement for propofol for BIS-guided induction of general anesthesia without any adverse effects.