Ultrasound-Guided Axillary or Infraclavicular Nerve Block for Upper Limb Surgery

Procedural sedation before the execution of the block. * 0.03 mg/kg iv bolus

0.75% (wt/vol) solution, 20 ml perineural injection

50 µg iv bolus prn for pain during surgery, up to 150 µg

General anesthesia will be induced if pain during surgery develops which is intractable with iv fentanyl ≤150 µg.

Blocks will be performed under high-resolution real-time ultrasound guidance. Patients will be in the supine position. With the abducted arm flexed 90° at the elbow, the transducer will scan for the axillary artery in its short-axis. Individual nerves will be sought for around the artery. A 22G, 17°-bevel needle will be advanced in-plane to inject aliquots of local anesthetic around each nerve structure up to the prescribed dose.

Blocks will be performed under high-resolution real-time ultrasound guidance. Patients will be in the supine position. The linear transducer will be initially positioned between the middle and lateral third of the clavicle, scanning on a parasagittal plane. The axillary artery and veins will then be sought for. We will try to visualize the three cords of the brachial plexus separately, and to inject local anesthetic around each of them. If this is not possible, the needle will be positioned cranially and posteriorly to the artery, and the injection will be made from there. A 20 G, 17°-bevel needle will be used for all blocks.