Single intravenous subanesthetic dose of esketamine failed to relieve postoperative pain in obese patients undergoing bariatric surgery: a randomized controlled clinical trial

Abstract

Background:Multimodal analgesia during bariatric surgery is beneficial to accelerate postoperative recovery. Esketamine has been used in anesthesia and analgesia. However, the analgesic effect of single infusion subanesthetic dose of esketamine in obese patients undergoing bariatric surgery is unclear yet. The study aimed to illustrate whether intraoperative intravenous subanesthetic dose of esketamine could relieve pain in bariatric surgery patients. Methods:Patients (n = 51) scheduled for laparoscopic bariatric surgery were randomly divided into two groups: the esketamine group (group E: 0.2 mg/Kg esketamine before surgical incision) or the saline group (group S: equivalent dose saline before surgical incision). The primary outcomes included pain in Post Anesthesia Care Unit (PACU) and on the first postoperative day (POD1), and the intravenous morphine equivalent (IVME) on POD1. The second measures included adverse reactions, postoperative nausea and vomitting (PONV), duration of extubation, incidence of intraoperative hypotension and first time out of bed after surgery. Results:Finally, 40 patients completed the study. PACU and POD1 numerical rating scale (NRS) scores revealed no significant difference, nor did IVME on POD1. Conclusions: Single infusion subanesthetic doses of esketamine does not relieve acute pain or reduce morphine consumption postoperative in patients undergoing bariatric surgery. To realize meaningful postoperative analgesic benefit, increased dosages or prolonged infusions of esketamine might be required. Trial registration: The study was registered at Chinese Clinical Trial Registry https://www.chictr.org.cn/, (Registration date: 7/12/2021; Identifier: ChiCTR2100054038).