Infraclavicular Nerve Block

Level of cords of Brachial Plexus

Lateral, Medial and Posterior (named according to relation to Axillary Artery)

Anatomy

Vertical ApproachVertical

Mid-point between anterior process on acromion and jugular notch (below clavicle)

Below the clavicle and lateral to subclavian artery

Pass needle in HORIZONTAL PLANE ONLY --- NO MEDIAL ANGULATION

Can be less than 2cm deep in thin patients

Note – lung may be less than 5m deep also

Subcoracoid ApproachSubcoracoid

Identify coracoid process

Mark a point 2cm inferior and 1-2cm medial

Pass needle in SAGITTAL PLANE ONLY --- NO MEDIAL ANGULATION

Depth = 3–8 cm

Distances and depth may need proportional adjustment in smaller patients

Motor responsesVertical Approach

Wrist / Finger Extension (posterior cord)

Don’t Accept: -Pectoral twitch (too superficial or medial)

Elbow flexion (lateral cord = too superficial or lateral)

No twitch (too lateral)

Subcoracoid ApproachWrist / Finger Extension (posterior cord)

Wrist flexion, Thumb adduction (if surgery in ulnar distribution – medial cord)

Don’t Accept : -Pectoral twitch (too superficial or medial)

Elbow flexion (lateral cord = too superficial or cephalad)

Posterior scapula movements (too deep, outside plexus)

Area AnaesthetisedTypical block includes hand, wrist, forearm, elbow, and distal arm.

Skin of the axilla and proximal medial arm is NOT blocked (intercosobrachial and medium cutaneous brachii nerves).

Nerves blockedChest – Anterior thoracic

Shoulder – Subscapular and Axillary

Arm, forearm and hand Musculocutaneous

Internal cutaneous

Lesser internal cutaneous

Median

Ulnar

Radial (musculospiral)

Pitfalls and Complications

Vertical ApproachSide-effects

Rarely laryngeal Nerve Block or Stellate Ganglion Block

ComplicationsVascular puncture

Inadvertent intravascular injection

Pneumothorax 1:1000

Subcoracoid ApproachSide-effects

Nil of note

ComplicationsVascular puncture

Inadvertent intravascular injection