Is wound infiltration with anesthetic effective as pre-emptive analgesia? A clinical trial in appendectomy patients

To assess the efficacy of wound infiltration with local anesthetic in reducing postoperative pain after a muscle-splitting incision for appendectomy. A double-blind, placebo-controlled, randomized clinical trial. The Royal Columbian Hospital, a university-affiliated community hospital. Forty-three patients scheduled to undergo emergency appendectomy were randomized into treatment (21) and control (22) groups. Five patients were excluded from the treatment group. Local anesthetic infiltration of the wound before incision (treatment group) and saline infiltration (control group). Postoperative analgesic requirements, pain assessment by visual analogue scale and length of hospital stay. No significant difference in analgesic use was seen between the 2 groups, as measured at 3 stages (Mc = control mean [standard deviation], Mt = treatment mean [standard deviation]): (a) in the recovery room, intravenous morphine use was Mt = 6.6 mg [8.6] v. Mc = 10.1 mg [7.2]; (b) in the first 2 postoperative days, intramuscular meperidine use was Mt = 309 mg [181] v. Mc = 278 mg [125] on day 1 and was Mt = 121 mg [132] v. Mc = 97 mg [128] on day 2; (c) in the final 5 days of follow-up, oral analgesic use was Mt = 11 [17] tablets v. Mc = 21 [16] tablets (acetaminophen with codeine). Pain assessments at rest, on a scale of 1 to 10, were found to be no different between groups, ratings being Mt = 4.7 [2.1] v. Mc = 4.5 [2.0] on day 1. Length of hospital stay averaged 3.0 days in both groups. Infiltration with local anesthetic before incision does not pre-empt postoperative pain from a muscle-splitting incision used for appendectomy.