Effect of intraoperative intravenous acetaminophen vs. intramuscular meperidine on pain and discharge time after paediatric dental restoration

Abstract

Background and objective: Enteral acetaminophen (paracetamol) has limited analgesic efficacy due to its delayed absorption and sub-therapeutic plasma concentration. Intravenous (i.v.) acetaminophen solves this issue and could thus provide adequate analgesia as a single agent. We compared intraoperative i.v. acetaminophen with intramuscular (i.m.) meperidine with regard to postoperative analgesia and readiness for discharge in paediatric patients undergoing day care dental restoration.

Methods: Forty children were randomized, in this double-blind study, to receive acetaminophen 15 mg kg-1 i.v. (Group A) or meperidine 1 mg kg-1 i.m. (Group M) after anaesthesia induction and before surgery. All patients received midazolam 0.5 mg kg-1 orally 30 min preoperatively and fentanyl 1 microg kg-1 i.v. immediately after induction. Anaesthesia was induced with either sevoflurane inhalation or propofol 3 mg kg-1 i.v. and was maintained with sevoflurane. Postoperatively, the objective pain scale, Ramsay sedation score, and Aldrete score were determined every 5 min until readiness for recovery room discharge (defined as achieving an Aldrete score of 10).

Results: Group A had slightly higher pain scores during early recovery compared with Group M (estimated marginal means: 3 +/- SEM 0.4 vs. 2 +/- SEM 0.4, respectively (95% CI for difference: 0.4, 2.6), P = 0.012 for F-test). In contrast, Ramsay scores were higher in Group M than in Group A during assessment period (estimated marginal means: 4 +/- SEM 0.3 vs. 2 +/- SEM 0.4, respectively (95% CI for difference: -2.3, -0.3), P = 0.013 for F-test). Group A patients achieved an Aldrete score of 10 sooner than those in Group M (5 +/- SEM 2 vs. 16 +/- SEM 4 min, respectively (95% CI for difference: -9, -14), P = 0.009).

Conclusion: Compared with i.m. meperidine, intraoperative i.v. acetaminophen resulted in slightly higher pain scores but earlier readiness for recovery room discharge in paediatric patients undergoing dental restoration. The potential economic benefit of early recovery room discharge needs to be further explored.