Esketamine reduces acute postoperative pain after short laparoscopic surgery in children: a randomized controlled trial

Postoperative pain in children remains undermanaged, highlighting an urgent need for opioid-sparing strategies. Esketamine offers potent analgesia with fewer side effects. This trial aimed to evaluate the efficacy of perioperative esketamine in reducing acute postoperative pain in children undergoing short laparoscopic surgery. Patients were randomly assigned in a 1:1 ratio to receive either a single intravenous dose of esketamine (0.5 mg/kg) or normal saline at induction. The primary outcome was the area under the curve (AUC) of Face, Legs, Activity, Cry, Consolability (FLACC) pain scores (F-AUC) over the first 48 postoperative hours. Secondary outcomes included FLACC scores at specific time points, the incidence of rescue analgesia, incidence of emergence delirium, and adverse events. Primary analyses were performed in the intention-to-treat population. A total of 104 randomized children were included in the primary intention-to-treat analysis ( n = 52 per group). The mean F-AUC in the esketamine group was significantly lower than that in the control group (mean difference: -4.60, 95% CI: -6.06, -3.13; P < 0.001). Only two children (3.8%) in the esketamine group required rescue analgesia compared to 28 children (53.8%) in the control group (RR = 0.071, 95% CI: 0.018–0.284, P < 0.001). Furthermore, FLACC scores at 10, 20, and 30 min after extubation were significantly lower in the esketamine group ( P < 0.001). The incidence of emergence delirium did not differ significantly between the esketamine group and the control group (9.6% vs. 15.4%; P = 0.555). There were no significant intergroup differences regarding postoperative adverse events, or hospitalization costs. A single intravenous dose of esketamine (0.5 mg/kg) provides effective adjuvant analgesia in children undergoing short laparoscopic surgery. It did not increase the incidence of emergence delirium, adverse events or economic burden. This trial was registered at the Chinese Clinical Trial Registry (Registration No.: ChiCTR2200065291; Date of Registration:2022-11-01).