Brachial Plexus Blocks for Upper Extremity Orthopaedic Surgery
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Review Article Brachial Plexus Blocks for Upper Extremity Orthopaedic Surgery Abstract Benjamin G. Bruce, MD Regional anesthesia of the upper extremity has several clinical Andrew Green, MD applications and is reported to have several advantages over general anesthesia for orthopaedic surgery. These advantages, Theodore A. Blaine, MD such as improved postoperative pain, decreased postoperative Lee V. Wesner, MD opioid administration, and reduced recovery time, have led to widespread acceptance of a variety of regional nerve blocks. Interscalene block is the most commonly used block for shoulder surgery. Other brachial plexus nerve blocks used for orthopaedic surgery of the upper extremity are supraclavicular, infraclavicular, From the Department of and axillary. Several practical and theoretical aspects of regional Orthopaedics (Dr. Bruce, Dr. Green, and Dr. Blaine) and the Department nerve blocks must be considered to optimize the beneficial effects of Anesthesiology (Dr. Wesner), and minimize the risk of complications. Warren Alpert School of Medicine at Brown University, Providence, RI. Dr. Green or an immediate family egional anesthesia is the admin- administration, decrease overnight member has received royalties from Tornier; serves as a paid consultant Ristration of local anesthetic hospitalizations, increase operating to IlluminOss Medical and Tornier; agents and adjuvants to specific ana- room efficiency, and reduce recovery has stock or stock options held in tomic areas, resulting in a combina- times.1 Recent studies of interscalene IlluminOss Medical and Pfizer; has received nonincome support (such tion of motor and sensory blockade. blocks have reported success rates as equipment or services), Regional anesthesia can be divided (ie, postoperative pain score ≤2of commercially derived honoraria, or into central blocks and peripheral 10) to be >99%.2 other non-research–related funding blocks based on the proximity of the William Halsted reported the first (such as paid travel) from Arthrex, Linvatec, Smith & Nephew, and infiltration site to the spinal cord. brachial plexus block in 1885, when Synthes; and serves as a board Brachial plexus block is a peripheral he described applying cocaine di- member, owner, officer, or block commonly used in both inpa- rectly to a surgically exposed bra- committee member of the American tient and outpatient settings for up- chial plexus.3 However, the morbid- Academy of Orthopaedic Surgeons and the American Shoulder and per extremity surgery and in postop- ity associated with open exposure of Elbow Surgeons. Dr. Blaine or an erative rehabilitation. The type of the brachial plexus limited its wide- immediate family member is a brachial plexus block used depends spread use. Percutaneous brachial member of a speakers’ bureau or has made paid presentations on on the type and magnitude of the plexus blockade was introduced in behalf of and serves as a paid surgery as well as patient characteris- the early 1900s and underwent sub- consultant to Zimmer. Neither of the tics and preferences. sequent refinements. The success of following authors nor any immediate Despite initial reluctance by ortho- brachial plexus blocks was greatly family member has received anything of value from or owns paedic surgeons to embrace regional improved with the development of stock in a commercial company or anesthesia, brachial plexus blocks transcutaneous neurostimulators in institution related directly or are now safely and effectively used the 1950s. The early stimulators indirectly to the subject of this for perioperative pain control for were rudimentary in design and of- article: Dr. Bruce and Dr. Wesner. many arthroscopic and open proce- ten failed to accurately localize the J Am Acad Orthop Surg 2012;20: dures. Compared with general anes- target nerve. Refinements in the de- 38-47 thesia, interscalene blocks have been sign allowed more accurate localiza- Copyright 2012 by the American shown to improve postoperative tion of the needle. Recently, the in- Academy of Orthopaedic Surgeons. pain, decrease postoperative opioid troduction of ultrasound-guided 38 Journal of the American Academy of Orthopaedic Surgeons Benjamin G. Bruce, MD, et al techniques has further improved Figure 1 block placement by allowing the an- esthesiologist to visualize the bra- chial plexus and needle during injec- tion.4 The success of upper extremity re- gional blocks is dependent on several factors, including the skill of the practitioner performing the block, patient characteristics, and needle lo- calization technique. The orthopae- dic surgeon must understand the benefits and risks of this important adjunct to upper extremity surgery. Anatomy The brachial plexus is composed of the peripheral nerves of the upper extremity from the root level to the terminal branches; it is classically de- Illustration of the anatomy of the brachial plexus. The bordered areas scribed as forming from the C5 represent the approximate target areas of the various blocks: interscalene, through T1 nerve roots (Figure 1). supraclavicular, infraclavicular, and axillary. (Redrawn with permission from Although all the musculature of the Netter FH: Atlas of Human Anatomy, ed 2. Teterboro, NJ, ICON Learning Systems, 1997.) upper extremity derives innervation from the brachial plexus, the cutane- ous innervation of portions of the pact in this region as it lies on top of plexus blocks have different indica- shoulder and upper arm is supplied the first rib, where it is closest to the tions for use in upper extremity sur- by nerves that are not part of the dome of the lung. The infraclavicular gery (Figure 3). The interscalene brachial plexus. The supraclavicular region is defined by the posterior sur- block is the most commonly used nerves, which supply the skin over face of the clavicle superiorly, the soft brachial plexus block. It is ideally the upper shoulder, derive from the tissues of the axilla inferiorly, the pec- suited for shoulder surgery. Intersca- third and fourth cervical roots. The toralis minor muscle anteriorly, and the lene blocks cover the supraclavicular axilla and medial aspects of the up- subscapularis muscle posteriorly. The nerves emanating from the third and per arm are supplied by the intercos- cords of the brachial plexus and sub- fourth cervical roots, thereby provid- tal brachial nerves from the second clavian vessels pass through this space ing sensory blockade to the skin to the upper extremity. At the level of thoracic nerve root. Consequently, overlying the shoulder. Compared the coracoid, the terminal branches be- an isolated brachial plexus nerve with suprascapular nerve block or gin to leave the cords, thereby reduc- block may fail to provide complete intraoperative bursal injection of lo- ing the likelihood that a single injection anesthesia of the upper extremity. cal anesthetic, interscalene block has can block the entire plexus at this level. The brachial plexus travels through been shown to provide superior pain The axillary region is a pyramidal four loosely defined anatomic regions: relief for subacromial acromio- space beneath the glenohumeral joint, interscalene, supraclavicular, infracla- plasty.5 Interscalene block can also located between the lateral chest wall vicular, and axillary. The interscalene be used for elbow surgery, although and the medial portion of the upper groove is the potential space between the sensory block may be less com- arm (Figure 2). the anterior and middle scalene mus- plete. It is not indicated for forearm cles. In the supraclavicular region, the or hand surgery because block of the brachial plexus emerges from the inter- Indications inferior trunk is often poor. This has scalene groove and travels laterally and been described as “ulnar sparing,” inferiorly beneath the clavicle. The di- Because of the differences in block and it is thought to result from the visions of the brachial plexus are com- distribution, the various brachial increased distance of the inferior January 2012, Vol 20, No 1 39 Brachial Plexus Blocks for Upper Extremity Orthopaedic Surgery Figure 2 Technical Considerations Sedation In adults, brachial plexus blocks should be performed on awake or mildly sedated patients by an experi- enced provider and with standard vi- tal sign monitoring and appropriate resuscitation equipment immediately available. The risk of sudden, unex- pected movements by the patient that might displace the needle or cause inadvertent damage to the bra- chial plexus or nearby structures is low. Upper extremity regional blocks Clinical photographs demonstrating the anatomic landmarks of brachial are not routinely performed on anes- plexus blocks. A, 1 = interscalene block, 2 = supraclavicular block, 3 = infra- clavicular block. B, 4 = axillary block. SCM = sternocleidomastoid muscle thetized patients because they are un- able to report early warning signs (eg, pain, paresthesias) or signs of lo- trunk from the site of local anes- from forearm tourniquet pain.7 Elici- cal or systemic toxicity (eg, heart pal- thetic injection.6 Factors that make tation of distal motor response in the pitations, perioral numbness, shortness interscalene block technically more posterior cord (finger or wrist exten- of breath). Although safe placement of difficult (eg, short neck, prior neck sion mediated through the radial interscalene block after induction of surgery) may present relative con- nerve) has been associated with the general anesthesia has been reported, most recent recommendations with traindications