II. Indications
- Anesthesia of the elbow, Forearm and hand
III. Precautions
- Does NOT block the axillary nerve
- Use supraclavicular block (or other higher Brachial Plexus Block) if shoulder Anesthesia is also required
IV. Background
- Originally described by Dr. William Halstead at Johns Hopkins in 1884
- Allowed superficial access to the brachial plaxus and its Anesthesia before Ultrasound
V. Technique: Ultrasound Guided
- Images
- Patient seated with arm forward flexed and adducted
- High frequency linear probe applied to the lateral arm as it exits the axilla
- Position the Ultrasound probe transverse (short-axis) to the arm, with indicator pointing superiorly
- Applied distal to the pectoralis major Muscle insertion on Humerus
- Needle insertion point will be directed superior to inferior, in-plane
-
Ultrasound Landmarks
- Orient biceps at screen left (lateral)
- Vessels
- Identify axillary artery and position in mid-frame
- Identify axillary vein with branches and position at screen right (medial)
- Identify deep tissues (conjoint tendon and latissimus dorsi overly Humerus)
- Nerves
- Musculocutaneous Nerve is inferior to biceps and lateral to artery
- Other nerves have variable course
- Medial brachial cutaneous nerve may be seen in superficial position
- Median Nerve (typically superficial)
- Ulnar Nerve (typically medial or deep to the Median Nerve)
- Radial Nerve (typically deep to the medial and Ulnar Nerves, anterior to the axillary artery)
- Needle Insertion
- Prepare skin with antiseptic
- Needle 5 cm, 22 gauge blunt tip needle
- Load syringe with a 20 cm total of Anesthetic (e.g. Ropivacaine)
- Direct needle from lateral (screen left) to medial (screen right)
- Deposit Anesthetic around the axillary artery (but NOT intravascular), typically in three regions of injection
- Follow the needle tip on Ultrasound and aspirate before injecting
- Inject deep to the axillary artery to anesthetize the Radial Nerve
- Inject in the region of the median and Ulnar Nerve (as well as the Medial brachial cutaneous nerve)
- Inject in the region of the Musculocutaneous Nerve
VI. Resources
- Ultrasound-Guided Axillary Brachial Plexus Block
- Janjua and Pak (2022) Axillary Block, Stat Pearls, Treasure Island, accessed 6/5/2022