Topical Magnesium Sulfate Versus Peritonsillar Bupivacaine for Post-Tonsillectomy Pain Relief in Children

Postoperative pain following tonsillectomy is a primary cause of morbidity in the pediatric population, frequently leading to "tonsillectomy distress syndrome," which is characterized by severe odynophagia, referred otalgia, and psychological distress. The underlying pathophysiology of this pain is complex, involving both mechanical trauma to the pharyngeal constrictor muscles and the chemical irritation of the vagus and glossopharyngeal nerve endings.

While perioperative analgesia is traditionally managed with local anesthetic infiltration, such as bupivacaine, its analgesic efficacy is typically limited to a short duration of 4 to 6 hours. Furthermore, the physical act of needle infiltration can induce tissue edema, distort surgical planes, and potentially elevate the risk of postoperative complications, including infection and hemorrhage.

Recent advancements in pain management have highlighted the role of N-methyl-D-aspartate (NMDA) receptors in peripheral tissues, presenting new avenues for non-invasive analgesia. Magnesium sulfate serves as an NMDA receptor antagonist by blocking its calcium channel in a voltage-dependent manner. This trial investigates whether applying magnesium sulfate topically to the tonsillar fossa can provide effective postoperative analgesia without the inherent risks associated with needle infiltration.

To ensure procedural standardization across the study, all tonsillectomies in this prospective, randomized trial will be performed utilizing a cold dissection technique under general anesthesia. Postoperatively, patients will be systematically evaluated to assess pain intensity, mucosal healing via a 5-point fibrin and epithelialization grading scale, and the overall requirement for rescue analgesics.