Background: In this study we compare the postoperative pain relief for inguinal herniotomy in children provided by instillation of bupivacaine into the wound with that provided by a caudal block.
Methods: Fifty-eight children aged 0-5 years having elective unilateral hernia repair were studied in this prospective, randomized, single-blind study. Anaesthesia was induced and maintained with oxygen, nitrous oxide, sevoflurane and propofol. Patients were randomly assigned to receive caudal analgesia with 1.0 ml.kg-1 body weight (BW) bupivacaine 0.25% or wound instillation with 0.2 ml.kg-1 BW bupivacaine 0.5% at the end of surgery. Pain was assessed over 24 h using a modified 10-point objective pain scale. During the first postoperative hour in the postanaesthesia care unit (PACU), intravenous (i.v.) piritramide (0.05 mg.kg-1) was administered to any child scoring 5 or more points on the pain scale. On the ward, rectal acetaminophen was administered by a staff nurse when considered necessary.
Results: Thirty children in the caudal group and 28 children in the wound instillation group were studied. There were no statistically significant differences between the groups regarding need for i.v. opioids, discharge time from the PACU and administration of acetaminophen. No statistically significant differences in postoperative pain score were observed in 16 of a total of 17 postoperative observations. No complications and no adverse effects were observed.
Conclusion: Instillation of bupivacaine into a wound provides postoperative pain relief following hernia repair, which is as effective as that provided by a postoperative caudal block.