Effect of intraoperative low-dose esketamine on postoperative quality of recovery in patients undergoing laparotomy for gynecologic malignancy: a randomized controlled trial

BACKGROUND: Gynecologic malignancy surgery with long midline incision and extensive surgical field often causes severe pain. We aimed to evaluate the benefit of low-dose esketamine on postoperative recovery after gynecologic malignancy laparotomy. MATERIALS AND METHODS: In total, 140 female patients scheduled for elective gynecologic malignancy laparotomy were randomly assigned to the esketamine group ( n = 70) or control group ( n = 70). Patients in the esketamine group received an intraoperative infusion of 0.25 mg/kg/h esketamine while those in the control group received an equivalent volume of saline. Both groups received a standard multimodal analgesic regimen that consisted of transversus abdominis plane block, acetaminophen, nonsteroidal anti-inflammatory drugs, and patient-controlled morphine. The primary outcome was the Quality of Recovery-40 (QoR-40) score at 48 hours postoperatively. Secondary outcomes included morphine consumption, pain scores, adverse effects, time to post-anesthesia care unit (PACU) discharge, postoperative depressive symptom on postoperative day 7, quality of life, and chronic pain at 3 months after surgery. RESULTS: The median QoR-40 score at 48 hours was 179 (164-190) in the esketamine group, which was not significantly different from 178.5 (163-186) in the control group (median difference, 1; 95% CI, -4 to 7; P = 0.643). Secondary outcomes were comparable between the two groups. Patients in the esketamine group had more over-sedation (20/69 [29.0%] vs. 8/70 [11.4%]; absolute risk difference (ARD), 17.6% [95% CI, 4.2-30.4%]; P = 0.010), and delayed discharge from PACU (19/69 [27.5%] vs. 4/70 [5.7%]; ARD, 21.8% [95% CI, 9.6-33.8%]; P = 0.001) compared to the control group. CONCLUSIONS: Intraoperative low-dose esketamine failed to further improve the QoR-40 score after gynecologic malignancy laparotomy when used as part of a multimodal analgesic regimen. Further research is needed to explore the optimal dosage and indications of esketamine in this patient population.