Effects of Subtenon Anesthesia Combined With General Anesthesia on Perioperative Analgesic Requirements in Pediatric Strabismus Surgery

Abstract

Pediatric strabismus surgery leads to undesirable intraoperative and postoperative side effects that include pain, postoperative nausea and vomiting (PONV), and oculocardiac reflex (OCR). We hypothesized that subtenon anesthesia performed before the start of surgery and combined with general intravenous anesthesia would reduce these adverse effects. Forty children (2.5 to 6 years of age, ASA status I to II) were prospectively randomized to receive either subtenon bupivacaine 0.5% or a saline injection before the beginning of surgery in a double-blind manner. Perioperative analgesic requirements, pain scores (CHEOPS scale), hemodynamics, and incidence of OCR and PONV were compared. Postoperative pain scores were lower (P < .001) at removal of the laryngeal mask and 30 minutes later in the bupivacaine group. Intraoperative and postoperative analgesic requirements were significantly reduced in this group (P < .01). The incidence of OCR and PONV were also significantly decreased (P < .01). Intraoperative values of blood pressure were significantly higher in the saline group at 20 minutes (P < .02). We conclude that preoperative subtenon bupivacaine 0.5% compared with a saline injection contributed to reduction of perioperative pain and undesirable side effects in pediatric strabismus surgery performed under general anesthesia.