Effectiveness of intra-operative wound infiltration with long-acting local anaesthetic.

Background: Postoperative pain relief is of importance to both patients and surgeons. One of the simpler techniques is infiltration of the surgical incision with long acting local anaesthetic. The literature is confusing, with numerous reports attesting to the value of this approach and a similar number disputing the demonstrable benefits.

Methods: A prospective, 'blinded', randomized trial was undertaken involving 18 females undergoing uncomplicated bilateral sapheno-femoral ligation. They received intraoperative bupivacaine infiltration into one or the other of their groin incisions. Postoperatively these patients were asked to assess a number of variables relating to their postoperative pain, each patient thereby acting as their own control.

Results: There was no significant difference in the postoperative pain experience between groins infiltrated with bupivacaine and those not infiltrated. Two patients developed wound infections and both of these occurred on the sides which had been infiltrated with bupivacaine, however this was not statistically significant. There was no difference found in pain experience with respect to pre- versus post-incision infiltration.

Conclusion: Intraoperative wound infiltration with bupivacaine is widely employed as a method of minimizing postoperative pain. This study was unable to demonstrate a benefit of employing the technique in terms of a reduction in the patient's perception of pain. By having each patient act as their own control, we have avoided one of the major deficiencies of previous studies, namely, interpatient variability in assessment and perception of pain.