Comparison of ketamine and fentanyl for postoperative pain relief in children following adenotonsillectomy.

Adenotonsillectomy has a high incidence of postoperative pain. Therefore, the purpose of this study was to evaluate the effectiveness and safety of either ketamine or fentanyl for postoperative pain relief in children following adenotonsillectomy. Sixty children aged 3-12 years, scheduled for adenotonsillectomy, were enrolled in this randomized, double-blind study. Patients were divided into two groups of 30 cases and received intravenous ketamine (0.5 mg kg(-1)) or fentanyl (1 microg kg(-1)). Modified Hannallah pain scale or Observational Pain Scores (OPS), nausea, vomiting, bleeding, rescue analgesia, sedation and post-anesthesia recovery scores were recorded both at first and 15th minute postoperatively. Moreover, patients receiving ketamine (group 1) or fentanyl (group 2) had comparable OPS and sedation score both on arrival and at 15th minute in the recovery room (p > 0.05). Although rescue analgesics were similarly required in both groups (p > 0.05), the time to reach rescue analgesia was shorter in group 1 (p = 0.001). Only one patient in fentanyl group had nausea and vomiting in the first 15 min that needed antiemetic in the recovery room. In conclusion, intravenous fentanyl (1 microg kg(-1)) compared with intravenous ketamine (0.5 mg kg(-1)) might provide extended time to first analgesic in children undergoing adenotonsillectomy. Interestingly, fentanyl and ketamine did not differ in post-operative vomiting.