Trial of three methods of intraoperative bupivacaine analgesia for pain after paediatric groin surgery

Purpose: To evaluate the relative effectiveness of three techniques of regiona Methods: Random assignment was made of 183 children scheduled for groin surgery to one of three groups. Bupivacaine 0.5% plain (2 mgkg(-1)) was injected by the surgeon after skin incision. Group A received wound infiltration. Group B had regional nerve blockade, Group C had a combination of both methods. Postoperatively, pain was assessed using the CHEOPS behavioural scale at half hourly intervals until discharge home. Satisfactory pain control was arbitrarily defined as a CHEOPS score of less than or equal to six. Potential differences among the groups were sought using graphical representation of mean pain scores, the frequencies of maximum pain:scores, and the incidence of postoperative vomiting and oral analgesic consumption. Results: Fifteen patients had to be excluded from analysis. This left 61 patients in Group A, 55 in Group B, and 52 in Group C. There were no demographic differences among the groups, No differences were demonstrated among the groups either in CHEOPS pain scores at any observation point (P = >0.8), or in the incidence of vomiting or need for postoperative analgesia. (P = 0.52 and P = 0.41 respectively). Overall, 80% of the observations made (1135/1425) met our definition-of satisfactory pain control. A post hoc calculation of the power of the study confirmed sufficient power to detect a 5% difference among groups. Conclusion: Al three methods achieved analgesia with 80% of the pain scores meeting our definition of satisfactory pain control. None of the techniques enjoyed any apparent advantage.