Interscalene regional anesthesia for shoulder surgery

Background: Despite a trend toward the use of regional anesthesia for orthopaedic procedures, there has been resistance to the use of interscalene regional block for shoulder surgery because of concerns about failed blocks and potential complications. Methods: We retrospectively reviewed the cases of 568 consecutive patients who had shoulder surgery under interscalene regional block in a tertiary-care, university-based practice with an anesthesiology residency program. The blocks were performed by a group of anesthesiologists who were dedicated to the concept of regional anesthesia in their practice. Complete anesthetic and orthopaedic records were available for 547 patients. The surgical procedure, planned type of anesthesia, occurrence of block failure, and the presence of complications were noted. Results: Of the 547 patients, 295 underwent an arthroscopic procedure and 252 (including eighty who had an arthroplasty) underwent an open procedure. General anesthesia was the initial planned choice for sixty-nine patients because of the complexity or duration of the procedure, the anatomic location, or patient insistence. Thirty-four of the sixty-nine patients also received an interscalene regional block. Interscalene regional block alone was planned for 478 patients. A total of 462 patients (97%) had a successful block whereas sixteen required general anesthesia because the block was inadequate. The success of the block was independent of the type or length of the surgery. No patient had a seizure, pneumothorax, cardiac event, or other major complication. Twelve (2.3%) of the 512 patients who had a block had minor complications, which included sensory neuropathy in eleven patients and a complex regional pain syndrome that resolved at three months in one patient. For ten of the eleven patients, the neuropathy had resolved by six months. Conclusions: Interscalene regional block provides effective anesthesia for most types of shoulder surgery, including arthroplasty and fracture fixation. When administered by an anesthesiologist committed to and skilled in the technique, the block has an excellent rate of success and is associated with a relatively low complication rate. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence