Randomized clinical trial of the influence of local subcutaneous infiltration vs subcutaneous and deep infiltration of local anaesthetic on pain after appendicectomy

INTRODUCTION: Local anaesthesia is commonly used to provide pain relief after surgery. The aim of this randomized, blinded prospective trial was to evaluate whether local subcutaneous and deep infiltration of local anaesthetic provides better postoperative pain control than subcutaneous infiltration alone.

METHOD: Eighty-four patients undergoing open appendicectomy for presumed acute appendicitis were randomly assigned into two groups. Group A received local infiltration of the skin prior to incision with bupivacaine whilst group B received half the bupivacaine infiltrated into the skin and the other half deep-to-external oblique to create a local nerve field blockade. Postoperative pain was assessed, on a scale of 1 to 10, at 1, 4, 8 and 24 h postextubation.

RESULTS: At time intervals of 1, 4 and 8 h, there was no significant difference in pain score between group A and group B. At 24 h group B had significantly lower pain scores than group A (2.3 vs 3.4, P = 0.016).

CONCLUSION: Both methods of administration of local anaesthetic produced consistently low pain scores in the first 24 h after appendicectomy. There may be additional benefit in a local nerve field blockade in combination with local anaesthetic skin infiltration.