Upper Extremity Blocks#

Brachial Plexus & Nerve Block Locations

Brachial Plexus

https://aneskey.com/brachial-plexus-block/

https://www.researchgate.net/figure/Idealized-brachial-plexus-Various-approaches-define-individual-brachial-plexus-blocks_fig4_24197528

Interscalene (ISB)#

  • Better shoulder coverage than Supraclavicular because reliably blocks above suprascapular nerve take-off.

  • Often misses ulnar distribution

  • 100% chance of Phrenic Nerve (C3,4,5). Transient Hemidiaphragmatic Paralysis.

  • Difficult to place catheter. Shallow, no muscle/ligament to anchor catheter.

interscalene-position

interscalene-injection

interscalene-dermatome

Supraclavicular#

  • “Spinal of the Arm”. Commonly used for primary regional anesthetic in hand room cases.

  • Low pneumothorax risk. Needle protected by 1st rib.

  • ~67% chance of Phrenic Nerve involvement

  • Difficult to place catheter. Shallow, no muscle/ligament to anchor catheter.

supraclav-position

supraclav-injection

supraclavicular-dermatome

Infraclavicular#

  • Similar coverage to Supraclavicular, little less reliable to get shoulder

  • Better for catheters. Pectoral muscle anchors catheter

  • Deep structure, steep needle angulation, difficult needle visualization

  • Higher pneumothorax risk. No bony protection against needle.

infraclav-position

infraclav-injection

infraclav-dermatome

Axillary#

  • Requires arm up positioning

  • No shoulder coverage

  • More targets. Nerves have branched out. Need to get around axillary artery for Radial/Ulnar/Median & separately get musculocutaneous.

  • Alternative to other brachial plexus blocks for anticoagulated patients as axillary region is compressible

axillary-position

axillary-injection

axillary-dermatome

Getting the T2 Dermatomal Distribution#

Intercostobrachial (ICB)#

  • Branch of T2. Not part of brachial plexus.

  • Often needed for tourniquet or AV fistula.

  • Anesthetize small subcutaneous nerves

ICB-distribution

ICB-location

Pectoralis (Pecs I/II)#

  • Fascial plane block

  • Covers axillary/shoulder nerves not innervated by brachial plexus

    • Proximal inner arm (T2/intercostobrachial distribution)

    • Axilla

    • Posterior Shoulder

  • Note: similar location to Serratus Anterior blocks, which is more lateral and in the axillary line

pecs-probe-position

pecs-nerves

Pecs 1 & pecs 2 block injection sites.

pecs-1-2-injection

Sources#

Most of resources/images taken from NYSORA which is a good site for learning/review. https://www.nysora.com/techniques/upper-extremity/