Chapter 134. Supraclavicular Block

Indications:

Surgery of the whole upper extremity, from clavicle and shoulder to the hand.

Contraindications:

• Contralateral phrenic nerve palsy
• Severe respiratory disease (especially of contralateral lung)
• Contralateral vocal cord/recurrent laryngeal nerve palsy

Technique using NS:

• Not recommended: high risk of pneumothorax

Technique using US (Figures 134-2, 134-3, and 134-4):

• Position patient with head of bed slightly elevated (in order to lower the shoulder) and head turned to the contralateral side
• Place the probe just above the clavicle, aiming almost toward the feet; locate the subclavian artery, with the brachial plexus lying immediately lateral and superficial to the artery. The plexus can have only a few large nerves, or many smaller ones. Typically, the distal contingent, coming from C8 and T1, lies deeper and closer to the artery, with occasionally nerves between the artery and the first rib. The proximal contingent, coming from C5–6–7, lies more superficial and lateral
• Also identify the pleura (deeper; bright line, mobile with deep inspiration) and the subclavian vein (more medial)
• Use Doppler to identify vessels that can occasionally course between the nerves, such as the cervical transverse artery or the dorsal scapular artery, in order to avoid vascular injury and intravascular injection
• Prep the skin lateral to the probe, and introduce a 100-mm needle in plane. Because of the proximity of the pleura, it is paramount to keep the needle tip in sight at all times. The probe can be rocked medially in order to provide more space to maneuver the needle (“heel-up” maneuver)
• Direct the needle into the “corner pocket” of the angle between the subclavian artery and the rib, being careful to avoid the nerves. A “pop” is often felt and seen when entering the plexus “sheath.” Do not contact the rib (periosteal contact is painful). Aspirate, and then inject local anesthetic solution
• Depending on the case, the needle may need to be repositioned two or three times in order to bathe all the visible nerves. Pay special attention to the nerves covering the area of surgery:
  • Proximal contingent if shoulder/upper humerus
  • Distal contingent if forearm/hand/wrist
• If nerves are seen between artery and rib, the needle might need to be advanced, after injecting local anesthetic to “open the space,” until those nerves are bathed as well
• Typically, 15–20 mL of local anesthetic solution is sufficient