Does the addition of morphine to brachial plexus block improve analgesia after shoulder surgery?

We have studied 40 patients undergoing elective shoulder surgery forchronically painful conditions. Patients were allocated randomly to twogroups and received interscalene brachial plexus block with 0.5%bupivacaine and adrenaline 1/200,000 40 ml either alone or with theaddition of morphine 5 mg. All patients also received a generalanaesthetic. The quality of the block, analgesic requirements and anycomplications or side effects were noted in the intraoperative period andduring the 48 h after operation. No significant difference was seen inquality of analgesia or patient satisfaction between the two groups.