Comparative effect of preemptive peritonsillar infiltration of ketamine versus dexmedetomidine on postoperative pain in children: a randomized controlled trial

Objectives: To assess the efficacy of peritonsillar infiltration of ketamine and dexmedetomidine on controlling post-tonsillectomy pain in children undergoing tonsillectomy. Methodology: This randomized, controlled, double-blind study involved 60 patients aged 5-12 years, both genders, and scheduled for elective tonsillectomy. General anesthesia (GA) was induced in all of the patients. The patients were randomized and divided into three groups. All three groups received a peritonsillar normal saline injection (1 mL for each tonsil). Group I received a saline injection without any additive; Group II with 1 μg/kg of dexmedetomidine, and Group III with 0.5 mg/kg of ketamine. After the anesthesia was over, the time to the first rescue analgesia was noted. The total amount of pethidine consumed, the time to start oral intake, and the Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores were noted at 30 min and 1, 2, and 4 hours postoperatively. Results: The time of 1st rescue analgesia was significantly prolonged in group II than group I and III (P1 < 0.001, P3 < 0.001, respectively) and in Group III than Group I (P2 = 0.011). The total amount of pethidine consumed by Group II and the time for starting oral intake were significantly lower in Group II (P < 0.001) and were insignificantly different between Groups I and III. Compared to Groups I and III, Group II had significantly lower Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores at 30 min and 1, 2, and 4 hours postoperatively (P < 0.05). In terms of postoperative complications, none of the three groups differed significantly (P > 0.05). There was no significant variation in the dosage of metoclopramide among the three groups. Conclusion: Compared to placebo, dexmedetomidine and ketamine infiltrated into the tonsils reduced postoperative pain more effectively. Dexmedetomidine also improved pain scores according to the CHEOPS scale at different postoperative time points and reduced the need for additional analgesics more effectively than ketamine. Abbreviations: CHEOPS: Children's Hospital of Eastern Ontario Pain Scale, GA: General anesthesia, NMDA: N-methyl-D-aspartate, PACU: post-anesthesia care unit Keywords: Anesthesia; Anaesthesia, General; Dexmedetomidine; Preemptive Analgesia; Peritonsillar Infiltration; Ketamine; Postoperative Pain; Tonsillectomy Citation: Eloraby M, Ghoneem H, ElgoharyM, Ebrahim N.Comparative effect of preemptive peritonsillar infiltration of ketamine versus dexmedetomidine on postoperative pain in children: a randomized controlled trial, Anaesth. pain intensive care 2025;29(6):497-504; DOI: 10.35975/apic.v29i6.2897 Received: February 04, 2025; Revised: July 09, 2025; Accepted: July 09, 2025