Background and Objectives To evaluate the efficacy of interscalene brachial plexus block as the primary anesthetic for shoulder surgery, the influence on blood loss, and the rate of complication.

Methods Retrospective review of 676 reconstructive surgical procedures of the shoulder for anesthetic technique (regional or general), regional anesthetic technique (paresthesia versus nerve stimulator), local anesthetic agent selected, success rate, estimated blood loss by procedures, and complications.

Results A total of 563 patients had interscalene anesthesia, exclusively, and 117 had general anesthesia. Mepivacaine, 1.4% with 1/200,000 epinephrine, was the most frequently used agent (480). Others included 0.5% bupivacaine (33) and 0.625% bupivacaine (50). Of 563 interscalene blocks attempted, 34 required general anesthesia to either initiate or complete the surgery (success rate, 94.1%) with 20 in the 0.5% bupivacaine group, 10 in the mepivacaine group, and 9 in the 0.65% bupivacaine group. For blood loss calculations, failed interscalene blocks were included with the general anesthesia group. Three surgical procedures were identified: total shoulder arthroplasty, acromioplasty with and without repair of the rotator cuff, and capsular advancement for recurrent shoulder dislocation. Comparing general and interscalene anesthesia, blood loss was less in the overall group and in the acromioplasty-rotator cuff group when interscalene block was compared to general anesthesia. There were four complications with two seizures and two subdural injections.

Conclusions Interscalene anesthesia is an effective anesthetic for elective shoulder surgery that may decrease intraoperative blood loss with a low complication rate.