Intraoperative low-dose esketamine on postoperative quality of recovery in patients undergoing open gynecologic surgery: a double-blinded, parallel-group, placebo- controlled trial.

Background: Gynecologic laparotomy surgery often leads to moderate to severe pain. Effective analgesia is essential for patient postoperative recovery. We aimed to evaluate the effect of low-dose esketamine on quality of recovery when used as part of multimodal analgesia in patients undergoing open gynecologic surgery.

Methods: 140 female patients undergoing gynecologic laparotomy under general anesthesia were randomly assigned to receive intraoperative infusion of either 0.25 mg/kg/h esketamine (study group) or an equivalent volume of normal saline (control group). The primary outcome was quality of recovery at 24 h postoperatively, assessed using the 40-item quality of recovery questionnaire (QoR-40). Secondary outcomes included morphine consumption, pain scores, functional outcomes, adverse events, postoperative depressive symptom, chronic pain, and health-related quality of life.

Results: The global QoR-40 score at 24 h was not significantly different between the two groups [study group, 178 (165-186); control group, 175 (164-186); median difference, 2; 95% CI, -3 to 7;  = 0.467). Secondary outcomes were comparable between the two groups. More patients in the study group had extubation time ≥ 10min (15.7% vs. 2.9%; = 0.009) and were over sedated (25.7 vs. 4.3%,  < 0.001) during post-anesthesia care unit stay.

Conclusions: Intraoperative infusion of 0.25 mg/kg/h esketamine had no additional benefit on early quality of recovery when used as part of multimodal analgesic regimen in patients undergoing open gynecologic surgery. Future investigations are needed to determine the optimal dosing regimen and identify subgroups of gynecologic patients who would benefit most from esketamine.

Trial Registration: Chinese Clinical Trial Registry; ChiCTR 2200061021.