The purpose of this study was to compare the relative analgesic efficacies of the postoperative intra-bursal infusion of bupivacaine, bupivacaine/morphine, and bupivacaine/fentanyl after shoulder arthroscopy.

At the end of subacromial arthroscopy, a continuous intra-bursal infusion catheter was inserted. A bolus dose was injected via the catheter just after the operation and a maintenance dose was infused for 4 days (1 ml/h). The bupivacaine group (Group B, n = 25), received 10 ml of 0.5% bupivacaine and 96 ml of 0.25% bupivacaine. The bupivacaine/morphine group (Group BM, n = 25) received 2 mg of morphine in 10 ml of 0.5% bupivacaine and 8 µg of morphine in 96 ml of 0.25% bupivacaine. And the bupivacaine/fentanyl group (Group BF, n = 25) received 100 µg of fentanyl in 10 ml of 0.5% bupivacaine and 400 µg of fentanyl in 96 ml of 0.25% bupivacaine. VAS at rest and exercise were evaluated preoperatively and postoperatively for 3 days. The frequency of IM rescue analgesic were recorded.

We did not find any significant differences in VAS, or in need for rescue analgesic between the three groups. Resting pain score was significantly reduced at the 2 nd- and 3 rd postoperative day versus the preoperative value in Group B and BM, and at the 3 rd postoperative day in Group BF (P < 0.05). Pain score at exercise was reduced at the 3 rd postoperative day versus the preoperative value in all groups (P < 0.05).

The combination of morphine or fentanyl with bupivacaine did not provide better postoperative analgesia than bupivacaine after shoulder arthroscopy.