Comparison of preoperative with postoperative lignocaine infiltration on postoperative analgesic requirements

Ninety patients undergoing appendicectomy were allocated randomly to receive 1.5% lignocaine 15 ml with adrenaline infiltrated into the proposed wound line 3 min before incision, lignocaine 15 ml with adrenaline infiltrated into the wound on closure or no wound infiltration. After operation, all patients received pethidine by patient-controlled analgesia. Pain scores were assessed while supine and sitting on day 1 and 2 and the cumulative pethidine dose administered was recorded at 12, 24, 36 and 48 h after operation. There were no significant differences in the cumulative dose of pethidine required or pain scores between the three groups at any time point after operation. We conclude that pre-incisional infiltration with 1.5% lignocaine had no advantage compared with infiltration at wound closure or no wound infiltration in reducing postoperative analgesic requirements or pain scores after appendicectomy.