Postoperative analgesic effects of intravenous acetaminophen vs intramuscular meperidine in children undergoing ambulatory herniotomy

ABSTRACT

Rectal acetaminophen has limited analgesic efficacy due to delayed absorption and subtherapeutic plasma concentration. Oral acetaminophen is not appropriate in the immediate postoperative period, i.v acetaminophen overcomes these problems and could provide adequate analgesia as a sole agent. This randomized double-blind study compared the analgesic effects of i.v acetaminophen and i.m meperidine in pediatric patients undergoing ambulatory inguinal herniotomy. Sixty children scheduled for unilateral inguinal herniotomy were randomized to receive either acetaminophen 15 mg/kg i.v [acetaminophen group], or 1 mg/kg meperidine i.m [meperidine group]. Anesthesia was induced by sevoflurane inhalation and maintained by sevoflurane in 50% N2O and O[2] through laryngeal mask airway. Postoperatively, Objective pain score, Ramsay sedation score and Aldrete score were recorded every 5 minutes for 30 minutes. Nursing satisfaction for postoperative analgesia was recorded on a 10 - point scale. Parent satisfaction for postoperative analgesia and postoperative nausea and vomiting was recorded on 4-point scale. Patients in acetaminophen group showed significantly low sedation scores during recovery room observation period. Objective pain scores were similar in both groups, as well as patients who required rescue analgesia, [25% in both groups]. Patients in acetaminophen group achieved an Aldrete score of 10 earlier than meperidine group. Parent satisfaction scores for postoperative analgesia were similar in both groups while those for postoperative nausea and vomiting showed significantly higher satisfaction scores in acetaminophen group. I.V acetaminophen achieved adequate analgesia comparable to that of i.m meperidine with less sedation, earlier readiness for discharge from recovery room and possibly less postoperative nausea and vomiting