[The effects of continuous interpleural vs. epidural infusion for postoperative pain relief following thoracotomy]

We studied whether continuous interpleural infusion of bupivacaine would be effective in alleviating pain after thoracotomy compared with effect of continuous epidural infusion of bupivacaine and buprenorphine. Twenty patients who had received thoracotomy and lobectomy were randomly divided into two groups to receive continuous interpleural infusion (IP group) of 0.5% bupivacaine at the rate of 5 ml.h-1 or continuous epidural infusion (E group) of 0.25% bupivacaine and 0.025 buprenorphine at the rate of 1 ml.h-1. The patients assessed their level of pain using a 100 mm visual analog scale (VAS) at rest and on coughing or changing the posture, verbal descriptor pain scale (VDPS), and times of supplemental analgesic. Assessment was performed at 7 points (mornings and evenings) for 3 postoperative days. In the evening of the day of surgery, VAS at rest in IP group was significantly higher than one in E group, but VASs at rest were similar in both groups from the first postoperative day to the third postoperative day. VAS on coughing or changing the posture in IP group was significantly higher than in E group in the evening of the day of surgery, and VASs on coughing or changing the posture in IP group were higher than in E group for 3 postoperative days. Supplemental analgesics were administered significantly more often than in E group in the evening of the first postoperative day. We conclude that continuous interpleural infusion does not give better analgesia than continuous epidural infusion after thoracotomy.