Analgesia for adenotonsillectomy in children: a comparison between peritonsillar infiltration of tramadol, ketamine, and placebo.

Introduction: Post-tonsillectomy pain is mediated by nociceptive C-fibers located at peritonsillar space. Peritonsillar infiltration of medication could relieve post-operative pain blocking the afferent via.

Purpose: To evaluate the effect of peritonsillar infiltration of tramadol, ketamine, and placebo on post-operative pain in cases of adenotonsillectomy.

Methods: This is a double-blind randomized placebo-controlled study. Children ASA I-II aged 3-13 years scheduled for adenotonsillectomy were included in the study. Patients were randomized to receive either 2 mg/kg of peritonsillar tramadol (Group T), 0.5 mg/kg of peritonsillar ketamine hydrochloride (Group K), and 3 mL of peritonsillar saline (Group P). Post-operative pain was recorded using the modified visual analogue scale at 2 h, 6 h, 12 h, and 24 h. Side effects, analgesia requirement, and first oral intake were also recorded.

Results: There were included 112 patients and five were excluded until final evaluation. We evaluated 36 children of Group T, 36 of Group K, and 35 of Group P. Groups were similar regarding to age, weight, height, gender, tonsil and adenoid size, hemodynamic parameters during the surgery, surgery, and anesthesia time. There were no differences between the groups in relation to pain scores, analgesia requirement, or first time of oral intake (p > 0.05). Group T presented a higher incidence of vomit between 2 and 6 h after surgery (p > 0.05).

Conclusion: This study showed that peritonsillar infiltration of tramadol or ketamine were not superior to placebo in reducing post-operative pain in children undergone adenotonsillectomy. The use of tramadol increased the risk of nausea and vomit between 2 and 6 h after surgery.