Nerve Block: Median

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 pt and laterality
• Apply topical anesthesia if needed
• Draw up 5-10 mL of anesthetic into syringe
  • Beware of toxic dose of anesthetic you're using Local Anesthetic Systemic Toxicity (LAST)
• Before any nerve block, perform neurovascular exam (often includes 2 pt discrimination w/ 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

Complications

• Bleeding
• Infection
• Pain
• Needle fracture
• Neurapraxia

See Also

• Nerve Blocks (Main)
• Local Anesthetic Systemic Toxicity (LAST)
• Median and Ulnar Block

Median Wrist Block

• Median Block at Elbow