The Effect Of Intraoperative Application Of Low Dose Ketamine On The Postoperative Depression-like Mood In Patients Undergoing Elective Orthopedic Surgery

Background and ObjectiveIncident rate of perioperative depression-like mood of inpatients was about 20～40%, which obviously resulted in negative impact on postoperative recovery of surgical diseases, but now the clinical therapeutic effect is poor. Resent researches indicated that ketamine had obviously antidepressive-like effect, but the mechanism was not clear, the overexpression of brain derived neurotrophic factors(BDNF) induced by ketamine may be one of its mechanism. In addition, some researchers found that the BDNF levels had good relationship between serum and brain, and the serum BDNF levels could be one of the indicators of the severity and therapeutic effect about depression disease. The main aim of the research is to observe the effect of low-dose ketamine on postoperative depression-like mood in patients undergoing elective orthopedic surgery and its relationship with BDNF level in serum.Methods120 patients who underwent elective orthopedic surgery with age 18-60 and ASA I-II were randomly divided into ketamine group (K) and control group(C). Group K:ketamine was given with injection of 0.5mg/kg (0.05ml/kg) at the time of intravenous anesthesia induction then continuous infusion with 0.25mg/kg.h (0.025ml/kg.h) ketamine for 30 minutes. Group C:saline were given with injection of 0.05ml/kg, then continuous infusion with 0.025ml/kg.h. Patient Health Questionair-9 (PHQ9) score and blood sample were collected at 1 day before operation and 1 day or 5 days after operation. The concentration of serum BDNF was analyzed by ELISA. Blood loss, operative time, VAS score at 1 d and 5d after operation and complications were recorded.ResultsAge, gender, intraoperative blood loss volume, operative time and preoperative PHQ-9 score had no statistic difference (P>0.05) between the two groups.. The PHQ-9 score at the preoperation、1d and 5d after operation in the C group had no statistic difference (P>0.05), but the PHQ-9 score at the 1d and 5d after operation was lower than that at the preoperation in the K group; Compared with PHQ-9 score of 1d or 5d after operation in the C group, the PHQ-9 score in the K group obviously decreases (P<0.05); The BDNF levels at the preoperation、1d and 5d after operation had no statistic difference in the C group (P>0.05), but the BDNF levels at the 1d and 5d after operation were higher than that at the preoperation in the K group; The preoperative BDNF levels in the two groups had no statistic difference (P>0.05), but compared with BDNF levels of Id or 5d after operation in the C group, the BDNF levels in the K group obviously increased (P<0.05); The PHQ-9 score was negatively correlated with the serum BDNF level.ConclusionIntraoperative application of low dose ketamine may alleviate postoperative depression-like mood in elective orthopedic operation, which could probably due to the increase of BDNF concentration induced by ketamine.