Pharm

Axillary Nerve Block

search

Axillary Nerve Block, Axillary Block, Ultrasound-Guided Axillary Nerve Block, Axillary Brachial Plexus Block

  • See Also
  1. Arm Regional Anesthesia
  2. Regional Anesthesia (Nerve Block)
  3. Point of Care Ultrasound (POCUS)
  • Indications
  1. Anesthesia of the elbow, Forearm and hand
  • Precautions
  1. Does NOT block the axillary nerve
  2. Use supraclavicular block (or other higher Brachial Plexus Block) if shoulder Anesthesia is also required
  • Background
  1. Originally described by Dr. William Halstead at Johns Hopkins in 1884
  2. Allowed superficial access to the brachial plaxus and its Anesthesia before Ultrasound
  1. Images
    1. axillaryBrachialPlexusNerveBlock.jpg
  2. Patient seated with arm forward flexed and adducted
  3. High frequency linear probe applied to the lateral arm as it exits the axilla
    1. Position the Ultrasound probe transverse (short-axis) to the arm, with indicator pointing superiorly
    2. Applied distal to the pectoralis major Muscle insertion on Humerus
    3. Needle insertion point will be directed superior to inferior, in-plane
  4. Ultrasound Landmarks
    1. Orient biceps at screen left (lateral)
    2. Vessels
      1. Identify axillary artery and position in mid-frame
      2. Identify axillary vein with branches and position at screen right (medial)
      3. Identify deep tissues (conjoint tendon and latissimus dorsi overly Humerus)
    3. Nerves
      1. Musculocutaneous Nerve is inferior to biceps and lateral to artery
      2. Other nerves have variable course
        1. Medial brachial cutaneous nerve may be seen in superficial position
        2. Median Nerve (typically superficial)
        3. Ulnar Nerve (typically medial or deep to the Median Nerve)
        4. Radial Nerve (typically deep to the medial and Ulnar Nerves, anterior to the axillary artery)
  5. Needle Insertion
    1. Prepare skin with antiseptic
    2. Needle 5 cm, 22 gauge blunt tip needle
    3. Load syringe with a 20 cm total of Anesthetic (e.g. Ropivacaine)
    4. Direct needle from lateral (screen left) to medial (screen right)
    5. Deposit Anesthetic around the axillary artery (but NOT intravascular), typically in three regions of injection
      1. Follow the needle tip on Ultrasound and aspirate before injecting
      2. Inject deep to the axillary artery to anesthetize the Radial Nerve
      3. Inject in the region of the median and Ulnar Nerve (as well as the Medial brachial cutaneous nerve)
      4. Inject in the region of the Musculocutaneous Nerve
  • Resources
  1. Ultrasound-Guided Axillary Brachial Plexus Block
    1. https://www.nysora.com/techniques/upper-extremity/axillary/ultrasound-guided-axillary-brachial-plexus-block/
  2. Janjua and Pak (2022) Axillary Block, Stat Pearls, Treasure Island, accessed 6/5/2022
    1. https://www.ncbi.nlm.nih.gov/books/NBK537201/