Continuous Axillary Block

Patient Position: Supine, with the arm abducted at 90° to 110° at the shoulder and flexed 90° at the elbow.

Indications:
Anesthesia and postoperative analgesia for surgery at the elbow and
below (hand and forearm) and continuous sympathectomy following finger
reimplantation.

Needle Size and Catheter: 18-gauge, 50-mm insulated introducing needle and 20-gauge catheter.

Volume and Infusion Rate: 30 to 40 mL of a mixture of 0.5% ropivacaine and 1.5% mepivacaine v/v, continuous infusion of 6 to 8 mL/hour 0.2% ropivacaine.

Anatomic Landmarks: Axillary artery in the middle portion of the axilla.

Approach and Technique:
The axillary artery pulse is palpated and marked in the middle of the
axilla. After disinfection, sterile draping, and local infiltration
with 1% lidocaine, a 50-mm insulated introducer needle or cannula
connected to a nerve stimulator (1.5 mA, 2 Hz, 0.1 ms) is inserted
above the artery, pointing in a proximal direction almost parallel to
the artery at a 30° to 45° angle to the skin (Fig. 27-1A).
After identification of a median, or radial nerve response at a current
below 0.5 mA, the volume is injected slowly (10 mL/min) and in 5 mL
increments. The catheter is then introduced and threaded approximately
5 cm beyond the needle tip (Fig. 27-1B). The introducing needle is removed and the catheter is secured in place and covered with a transparent dressing (Fig. 27-1C).