Preemptive Topical Ketamine for Post-Tonsillectomy Analgesia: A Randomized, Double-Blind, Placebo-Controlled Trial in Children

Adenotonsillectomy is one of the most frequently performed surgical procedures in pediatric patients and is associated with significant postoperative pain. Effective analgesia remains challenging due to the need to balance efficacy with safety, particularly avoiding opioid-related respiratory complications. Topical ketamine, a non-competitive NMDA receptor antagonist, has been proposed as a peripheral analgesic strategy capable of reducing nociceptive signaling without significant systemic effects.

This study was designed as a prospective, randomized, double-blind, placebo-controlled trial conducted at a tertiary care center. A total of 420 pediatric patients (ASA I-II, aged 4-12 years) scheduled for elective adenotonsillectomy were enrolled. Participants were randomized in a 1:1 ratio to receive either a ketamine gargle (40 mg diluted in 30 mL saline) or a placebo saline gargle administered 5 minutes before induction of anesthesia.

All patients underwent standardized anesthetic and surgical protocols to minimize confounding variables. Pain intensity was assessed using the Visual Analog Scale at 0, 4, 8, 12, and 24 hours postoperatively. Secondary outcomes included incidence of postoperative hemorrhage requiring surgical reintervention, total rescue analgesic consumption, and adverse events such as nausea, vomiting, sedation, or psychomimetic effects.

The primary objective was to evaluate the analgesic efficacy of preemptive topical ketamine. Secondary analyses explored its potential impact on postoperative morbidity, particularly bleeding events. This study was conducted in accordance with ethical standards and CONSORT guidelines.