Nerve Block: Median

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Background

  • Useful for lacerations across multiple fingers/palm instead of multiple digit blocks
  • Useful for exploration of flexor tendons of digits 1-3
The yellow area indicates the area of the hand innervated by the median nerve

Indications

  • Trauma or need to perform painful procedure on area innervated by median nerve

Contraindications

  • Infection overlying injection site
  • Previous allergic reaction to local anesthesic used
  • Distortion of anatomic landmarks

Equipment Needed

  • Topical anesthesia (LET, EMLA)
  • local anesthesia
    • Lidocaine 1% (lasts 30-60 minutes or longer if given with epi, rapid onset)
    • Mepivacaine 3% (lasts 45-90 minutes, slower onset)
    • Bupivacaine 0.5% (lasts 2-4 hours, slowest in onset)
  • 18G needle to draw up anesthetic
  • 25-30G needle to inject
  • 10 cc syringe
  • Gauze pads

Procedure

  • Time out, confirm correct patient and laterality
  • Apply topical anesthesia if needed
  • Draw up 5-10 mL of anesthetic into syringe
  • Before any nerve block, perform neurovascular exam (often includes 2 patient discrimination with paperclip)

Wrist Block

Median nerve lies between palmaris longus and flexor carpi radialis.
  • Median nerve is within the carpal tunnel
  • Between palmaris longus and flexor carpi radialis
  • Insert needle perpendicular between tendons, 2-3 cm proximal to the distal crease of the wrist
  • Aspirate; if no blood inject a few mL's of anesthetic slowly
  • Test sensation to pain distal to block

Elbow Block

Complications

  • Bleeding
  • Infection
  • Pain
  • Needle fracture
  • Neurapraxia

See Also

References