Postoperative vomiting (POV) after strabismus surgery in children results in discomfort and prolonged hospital stays. Opioids increase the incidence of POV. Remifentanil has a context-sensitive half-life of 3 to 4 min, and how this short half-life influences POV in those patients is unknown. We conducted a prospective, double-blinded study in 81 ASA status I or II children from 2 to 12 yr of age undergoing elective strabismus surgery under general anesthesia. Patients were randomized to receive either remifentanil (bolus 1 microg/kg; infusion 0.1-0.2 microg x kg(-1) x min(-1)) or fentanyl (2 microg/kg, and 1 microg/kg every 45 min). POV episodes were recorded for 25 h. Pain scores were obtained by using an objective pain scale for 60 min during recovery. The number of patients who experienced POV did not differ significantly between groups (49% vs 48%). However, in the Remifentanil group, POV episodes were significantly less frequent (0.95 vs 2.2 episodes). In contrast, fentanyl was associated with lower pain scores during the first 30 min of recovery. We conclude that children undergoing strabismus surgery under balanced anesthesia with remifentanil, compared with fentanyl, showed less frequent POV. However, early postoperative analgesia was better with fentanyl.
Implications: Opioids increase the incidence of postoperative vomiting (POV). Remifentanil is characterized by the shortest half-life of all opioids used in anesthetic practice. Therefore, we studied the effect of remifentanil on POV compared with the longer-acting opioid fentanyl in children undergoing strabismus surgery.