Effect of intraoperative application of ketamine on postoperative depressed mood in patients undergoing elective orthopedic surgery

Abstract

Purpose: A depressed mood frequently occurs in perioperative patients, negatively impacting patient recovery. Recent studies suggested that ketamine has a rapid, obvious, and persistent antidepressant effect. The purpose of this study was to investigate the impact of intraoperative application of ketamine on postoperative depressive mood in patients undergoing elective orthopedic surgery.

Methods: This was a randomized, double-blind, controlled study. A total of 120 patients (ASA grade I-II) undergoing elective orthopedic surgery were divided randomly into a ketamine group (group K) and a control group (group C). In the K group, 0.5 mg/kg (0.05 ml/kg) ketamine was given at induction of anesthesia, followed by 0.25 mg/kg/h (0.025 ml/kg/h) continuous infusion for 30 min. In the C group, 0.05 ml/kg 0.9 % saline was used at induction of anesthesia, followed by 0.025 ml/kg/h continuous infusion of saline for 30 min. PHQ-9 score was recorded preoperatively (1 day before surgery) and postoperatively (on day 1 and day 5 following surgery). Blood at these time points was drawn for serum brain-derived neurotrophic factor (BDNF) level analysis. Intraoperative blood loss, surgery time, postoperative visual analog scale pain scores and perioperative complications were also recorded.

Results: There were no differences in age, sex, surgery time, blood loss, and preoperative PHQ-9 scores between the two groups (P > 0.05). There were no differences in PHQ-9 scores preoperatively and postoperatively for the C group (P > 0.05); however, the PHQ-9 postoperative scores were lower than the preoperative PHQ-9 scores in the K group (P < 0.01). Postoperative PHQ-9 scores of K group were lower than those of C group (P < 0.05). There were no differences in serum BDNF levels in C group pre- to postoperatively (P > 0.05). Compared with the preoperative BDNF levels of K group, postoperative BDNF levels in K group increased significantly (P < 0.01). An inverse correlation between PHQ-9 score and serum BDNF level was shown.

Conclusion: Intraoperative application of ketamine was associated with improved scores for depressed mood and increased serum BDNF levels in patients undergoing elective orthopedic surgery.

Keywords: BDNF; Ketamine; PHQ-9 score.