Evaluation of interpleural bupivacaine block for postoperative pain relief after major renal surgery

Despite the large positive experience with pleural analgesia after cholecystectomy, only a few studies have evaluated the method for treatment of nephrectomy pain. This study was performed to evaluate the efficacy of pleural analgesia after major renal surgery by evaluating the pain scores, IV opioid requirement and the first time for request for analgesia. 88 patients were randomly assigned to one of two equal groups, group I received loading IV morphine [3mg], half an hour before recovery from anaesthesia, then each patient was connected to the PCA device immediately postoperatively, while the patients in group II an interpleural catheter was inserted by the surgeon under direct vision and 20ml bupivacaine 0.5% was injected half an hour before recovery, followed by 20ml bupivacaine 0.25% every 6 hours. Pain scores [10-cm visual analog scale] and opioid requirements were recorded over the first 24 hours postoperative. Patient characteristics were similar in each group, as was the duration of surgery. The VAS in the interpleural group showed a significant reduction in the pain score half an hour after each interpleural bupivacaine injection with an overall lower pain scores than that of the PCA group both at rest and on coughing. The morphine requirement was significantly less in those given pleural bupivacaine [15 +/- 3mg] than in those given morphine alone [36 +/- 6mg]. Furthermore, the time from completion of surgery until the first opioid request was significantly longer in the patients who received bupivacaine [5.4 +/- 0.6 Vs 2.8 +/- 0.8 h]. We conclude that pleural analgesia significantly prolongs the time until postoperative opioid was first requested and halves the total required dose. These data indicate that pleural analgesia is effective and provides a significant opioid-sparing effect