A comparison of two concentrations of bupivacaine and adrenaline with and without fentanyl in paediatric inguinal herniorrhaphy

This study was designed to determine whether administration of caudal bupivacaine with fentanyl would have any effect on analgesia in paediatric patients undergoing inguinal herniorrhaphy repair. Fifty-six outpatient paediatric patients undergoing inguinal hernia repair were evaluated. Patients received, in a randomized manner, 1 ml.kg-1 of either bupivacaine 0.25% or 0.125% with or without fentanyl 1 microg.kg-1. There was no difference in pain scores in the hospital, the night of surgery, or 24 h postoperatively nor was there a difference in the oral analgesics administered between any of the groups. There was a higher incidence of vomiting at home in both 0.25% bupivacaine groups irrespective of the use of fentanyl. The 0.125% bupivacaine group had significantly more patients who received intravenous fentanyl in the PACU than did the other three groups (P<0.001). Increasing the concentration of bupivacaine from 0. 125% to 0.25% increased the incidence of postoperative vomiting. We recommend that clinicians utilize bupivacaine 0.125% with 1 microg. kg-1 fentanyl as the caudal injectate in paediatric patients undergoing inguinal hernia repair.