Comparing the Effect of Preoperative Administration of Melatonin and Passiflora incarnata on Postoperative Cognitive Disorders in Adult Patients Undergoing Elective Surgery

BACKGROUND: Anxiety is a preoperative complication, which most patients encounter. The use of a premedication to reduce preoperative anxiety with minimal cognitive impairment is crucial. OBJECTIVES: This study was conducted to compare the sedative effect of preoperative melatonin and Passiflora incarnata in patients undergoing elective surgery regarding their potential for postoperative cognitive disorders. METHODS: In this clinical trial, 52 patients American society of anesthesiologists grade (ASA) I and II of both genders were selected to receive either Passiflora incarnata (1000 mg nature made) (n = 26) or melatonin (6 mg) (n = 26) as premedication one hour before surgery. Post-operative pain was evaluated using the visual analogue scale (VAS). Patient’s anxiety and cognitive dysfunction was evaluated with the Ramsey score and the digital symbol substitution test (DSST), respectively. All tests were carried out and evaluated at arrival in the operating room, before induction and before discharge from the post anesthesia care unit (PACU). RESULTS: There were no statistically differences between groups in VAS (P > 0.05). However, the mean score of pain was higher in the melatonin group compared to the Pssiflora incarnata group when discharged from the PACU (27.63 vs. 25.37). The anxiety scores were statistically significant in both drugs (P = 0.001), however higher sedation scores was caused by premedication with melatonin (P = 0.003 vs. 0.008). Regarding the DSST, there was a significant difference between the two groups one hour before the surgery (P = 0.04) and at the time of discharge from the PACU (P = 0.007). When evaluating each group, the Passiflora incarnata group revealed a significant difference (P = 0.003). CONCLUSIONS: Our findings show that premedication with Passiflora incarnata reduces anxiety as well as Melatonin. However, Melatonin causes less cognitive impairment compared to Passiflora incarnata.