Preoperative Oral Dextromethorphan Does Not Reduce Pain or Analgesic Consumption in Children After Adenotonsillectomy

Abstract

In this randomized, double-blinded, placebo-controlled, prospective study, we evaluated the analgesic efficacy of dextromethorphan 0.5 mg/kg or 1.0 mg/kg PO 1 h before adenotonsillectomy in 57 children 6-12 yr of age. Anesthetic management was standardized. Morphine 0.075 mg/kg IV and acetaminophen 25-35 mg/kg PR were administered after anesthetic induction but before the start of surgery. A 4-point behavioral score (1 = asleep, 2 = awake and calm, 3 = awake and crying, 4 = thrashing) was recorded on admission to and discharge from the postanesthesia care unit (PACU). In the PACU, pain was assessed with Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) and recorded every 15 min until the patient was transferred to the day surgery unit (DSU). In the DSU, patients rated their pain using a 10-cm baseline 0-10 visual analog pain scale (VAS) every 30 min until they were discharged home. A 24-h VAS was obtained by phone interview, and parental satisfaction was scored (yes/no) regarding their child's postoperative analgesia. Morphine 0.025 mg/kg IV was administered to children with CHEOPS score >6, who verbalized pain, or who were crying in any consecutive 5-min observation periods in the PACU. Total morphine consumption was recorded. The study groups were comparable with respect to demographic variables. We were unable to detect any differences between study groups with respect to postoperative morphine consumption, CHEOPS, behavior scores, VAS, or parental satisfaction. Implications: Premedication with dextromethorphan 0.5 or 1.0 mg/kg PO does not improve postoperative analgesia in school-aged children who receive preemptive morphine 0.075 mg/kg IV and acetaminophen 25-35 mg/kg PR during nitrous oxide and desflurane anesthesia for adenotonsillectomy. (Anesth Analg 1999;88:749-53)