Intrathecal morphine for postoperative analgesia following repair of frontal encephaloceles in children: Comparison with intermittent, on-demand dosing of nalbuphine

Abstract

Study Objective: To determine the efficacy of lumbar intrathecal (IT) morphine in a dose of 0.02 mg/kg in providing analgesia following repair of frontal encephaloceles. Design: Prospective, open-label investigation of IT morphine with secondary comparison to a retrospective cohort. Setting: Metropolitan hospital in the Philippines. Patients: 24 ASA physical status I and II children undergoing frontal encephalocele repair. Interventions: Following induction of general anesthesia, IT morphine (Group 1) was administered via single-shot technique or through a lumbar IT drain placed for cerebrospinal fluid drainage during the surgical procedure. Postoperative analgesia was assessed by visual analog score in patients greater than 5 years of age or a behavioral score in patients less than 5 years of age. The retrospective cohort received postoperative analgesia with intermittent doses of intravenous nalbuphine (Group 2). Measurements and Main Results: Group 1 had decreased postoperative analgesic requirements, decreased intraoperative inhalational anesthetic requirements, and a longer time to the first request for postoperative analgesia than Group 2. The time to the first request for postoperative analgesia was 16.0 ± 9.1 hours in Group 1 and 1.6 ± 1.2 hours in Group 2 ( p < 0.0001). Six of 12 patients in Group 1 required no analgesic drugs during the first 24 postoperative hours while all 12 patients in Group 2 ( p = 0.02) did require analgesic drugs during this period. The patients in Group 1 who did not require supplemental analgesic drugs maintained pain scores of 2 or less throughout the first 24 postoperative hours. Conclusion: Lumbar IT morphine provides effective analgesia following repair of frontal encephaloceles in children and adolescents.