ULTRASOUND-GUIDED AXILLARYÂ BRACHIAL PLEXUS BLOCK
Analgesia distal to the elbow
INDICATIONS
Blocks at the terminal branches of the brachial plexus (medial, ulnar & radial)
The musculocuteanous nerve must be blocked separately.
CONTRAINDICATIONS
Absolute contraindications:
Patient refusal
Infection at injection site
Significant coagulation abnormalities
Relative contraindications:
Inability to cooperate during block placement or surgery
Preexisting neurologic disease
LANDMARKS
Axilla at the crease formed by pectoralis major muscle and biceps muscle
Axillary artery
SUPPLIES
Patient monitoring devices
Ultrasound equipment & a high-frequency linear transducer
Appropriately-sized sterile gloves
Local anesthetic for local infiltration with a small-gauge needle
Local anesthetic of choice and syringes
Echogenic needle
Lubricating jelly
Probe cover
Sterile skin cleansing solution
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*Always have emergency equipment/drugs available*
TECHNIQUE
Apply patient monitoring devices.
Position the patient supine and abduct the patient’s arm 90°.
Avoid excessive abduction as it may produce tension of the brachial plexus.
Don sterile gloves and cleanse the site with a sterile skin cleansing solution.
Place a sterile probe cover and lubricating jelly over the ultrasound probe.
Place the ultrasound probe in the axilla at the crease formed by the pectoralis major and biceps muscle.
Identify the pulsating axillary artery and the terminal nerve branches of the brachial plexus around the artery (median, ulnar, and radial).
They may not always be visualized.
Localize the skin.
Insert the needle in-plane anterior to the brachial plexus and directed toward the posterior aspect of the axillary artery.
A U-shape distribution of local anesthetic around the axillary artery results in the block of the median, radial, and ulnar nerve. Inject 20-25 mL of local anesthetic while visualizing the spread.
To decrease the risk of intravascular injection, frequent aspiration and slow administration of local anesthetic are critical.
Identify the musculocutaneous nerve located between the coracobrachialis muscle and the pectoralis major muscle. It is visualized lateral to the axillary artery.
Inject 5-10 mL of local anesthetic around the nerve under direct observation.