Difference between revisions of "Nerve Block: Median"

(placed elbow instructions and another image)
(Background)
Line 2: Line 2:
 
*Useful for lacerations across multiple fingers/palm instead of multiple digit blocks
 
*Useful for lacerations across multiple fingers/palm instead of multiple digit blocks
 
*Useful for exploration of flexor tendons of digits 1-3
 
*Useful for exploration of flexor tendons of digits 1-3
 +
*Ultrasound guidance significantly increases the success rate of this block
 
[[File:Handnerves.png|thumbnail|The yellow area indicates the area of the hand innervated by the median nerve]]
 
[[File:Handnerves.png|thumbnail|The yellow area indicates the area of the hand innervated by the median nerve]]
  

Revision as of 03:07, 9 April 2017

Background

  • Useful for lacerations across multiple fingers/palm instead of multiple digit blocks
  • Useful for exploration of flexor tendons of digits 1-3
  • Ultrasound guidance significantly increases the success rate of this block
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 epinephrine, 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

Median nerve lies between palmaris longus and flexor carpi radialis.
  • 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 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

Upper Extremity Nerves
  • Cleanse the skin overlying the antecubital fossa with chosen antiseptic
  • Create a sterile field using sterile drape
  • In a sterile fashion, apply a small wheel of local anesthetic to the area immediately proximal to the antecubital fossa
  • Palpate the brachial artery to be aware of its path
    • The median nerve should be approximately 1 cm medial to the brachial artery at this point
  • Insert the needle approximately 1-2 cm proximal to the flexor crease and advance with negative pressure applied to the syringe
  • At 1-2 cm deep, aspirate prior to injection to rule out intravascular placement
  • Inject 5-10 mL of local anesthetic

Complications

  • Bleeding
  • Infection
  • Pain
  • Needle fracture
  • Neurapraxia

See Also

External Links

References