Brachial plexus block for pain relief after modified radical mastectomy.

Brachial plexus block using an intraclavicular approach was performed at the completion of surgery in 47 patients having modified radical mastectomies. In 48 control patients having similar operations, brachial plexus block was not performed. Of the 47 patients in whom brachial plexus block was performed, 26 (55%) required analgesia during the first 24 hours after the operation, whereas 44 (91%) of the 48 control patients required analgesics (p less than 0.0005). The time elapsed between the end of anesthesia and requirement of the first analgesic was significantly longer when the brachial plexus was blocked (p less than 0.001). The efficacy, simplicity, and safety of blocking the brachial plexus at the completion of surgery following modified mastectomy demonstrate that this technique could be routinely used for the relief of postoperative pain in patients having modified radical mastectomies.