Pharm

Superior Trunk Block

search

Superior Trunk Block, Upper Brachial Plexus Trunk Block, Superior Trunk Nerve Block, Upper Trunk Block, Ultrasound Guided Superior Trunk Block

  • See Also
  1. Supraclavicular Nerve Block
  2. Superficial Cervical Plexus Nerve Block
  3. Interscalene Nerve Block
  4. Brachial Plexus
  5. Regional Anesthesia (Nerve Block)
  6. Local Skin Anesthesia
  7. Point of Care Ultrasound (POCUS)
  • Indications
  1. Shoulder Anesthesia
  2. Alternative to the Interscalene Nerve Block, with less transient phrenic nerve paralysis risk
  • Background
  1. Superior brachial trunk forms from joining of the C5 and C6 nerve roots
  2. Superior Trunk Block targets this trunk as it gives off the suprascapular nerve branch
  3. Suprascapular nerve innervates the skin over the clavicle and the cape of the Shoulder
    1. Exits posterior to sternocleidomastoid Muscle and over the top of the middle scalene Muscle
    2. Divides into medial, intermediate and lateral branches
  • Complications
  1. See Regional Anesthesia
  2. LAST Reaction
  3. Phrenic Nerve paralysis (transient)
    1. Less common than with Interscalene Nerve Block
  • Technique
  1. Images
    1. superiorTrunkNerveBlock.jpg
  2. Equipment
    1. Needle 22 gauge, 5 to 10 cm blunt tipped or short bevel Nerve Block needle
    2. Anesthetic (Ropivacaine) 10 to 15 ml
  3. Ultrasound (high Frequency linear probe)
    1. Similar approach as for Interscalene Nerve Block
    2. Ultrasound probe in transverse plane along the lateral neck
    3. Start at the supraclavicular fossa
      1. Subclavian artery medial
      2. Brachial Plexus lateral
    4. Slide probe upward where the superior trunk divides proximally into its C5, C6 roots
      1. Identify anterior scalene Muscle medial
      2. Identify cervical roots: C5, C6
      3. Identify supraclavicular nerve (lateral and superficial)
      4. Identify middle scalene Muscle lateral
  4. Injection
    1. Needle inserted in-plane lateral to medial
    2. Direct needle toward (but not contacting) C5 and C6 and inject 10 ml in this region
    3. Withdraw and redirect needle toward supraclavicular nerve and inject another 5 ml in this region
      1. Supraclavicular nerve runs over the surface of the middle scalene Muscle
      2. Injecting over the middle scalene surface will anesthetize the supraclavicular nerve
  • Resources
  1. Superior Trunk Block (Chin, YouTube)
    1. https://www.youtube.com/watch?v=938F1O90S34
  • References
  1. Chin (2014) Can J Anaesth 61(12): 1098-102 [PubMed]
  2. Kim (2019) Anesthesiology 131:521-33 [PubMed]