Intraoperative Esketamine Is Effective at Reducing Acute Postoperative Pain in Bariatric Surgery Patients: a Randomized Control Trial

Background The analgesic effect and postoperative effects of esketamine are not yet clear in bariatric surgeries. Many bariatric surgery patients suffer from acute abdominal pain after surgery which leads to increased opioid use. This study aimed to determine whether intraoperative use of esketamine could reduce acute postoperative pain in bariatric surgery patients. Methods We designed a randomized double-blinded controlled trial. Included patients between the ages of 18 and 50 years with a body mass index ≥27 kg/m 2 and American Society of Anesthesiologists Physical Status of I-III, scheduled to undergo sleeve gastrectomy. We divided them into two groups, the control group which received a placebo, and the esketamine group which received a loading dose of esketamine 0.2 mg/kg and a maintenance dose of 0.2 mg/(kg·h) along with other anesthetic drugs during the surgery. After the surgery, they were assessed for Numerical Rating Scale (NRS) pain scores and Post Operative Nausea and Vomiting (PONV) scores, while other surgical data were recorded during the surgery. Results We enrolled 68 patients, 52 females, and 16 males. The 0.5 h, 1 h, 2 h, 6 h, and 12 h NRS scores were significantly lower in the esketamine group compared to the control group, and the extra painkillers administered were significantly lower in the esketamine group ( p <0.05). Conclusion Intraoperative use of esketamine can reduce acute postoperative pain in bariatric surgery patients. Further studies should explore whether the reduced pain is due to the anti-depressive effect of esketamine or purely the analgesic effect. Trial registration Chinese Clinical Trial Registry (ChiCTR2100054038, https://www.chictr.org.cn/com/25/showproj.aspx?proj=142806 ) Graphical Abstract