Nerve Block: Upper Extremity
Indications
- greater pain relief in a larger area for wound exploration, irrigation, and repair without distoring local anatomy
Contraindications
- allergic reaction to anesthetic
- patients with proximal vascular grafts or AV fistulas
- overlying skin infection
Equipment Needed
- Syringe
- 18 gauge needle
- 25-27 gauge needle
- chlorhexadine
- sterile gloves
- Local Anesthetic (lidocaine without epi, bupivacaine)
- sterile drapes
- gauze
- bandage
Anatomy
Median Nerve Distribution:
Radial Nerve Distribution:
Procedure
- Obtain informed consent
- Perform and document a thorough neurovascular examination of the extremity
- Draw up your anesthetic and load a 25-27 gauge needle
- position the patient so that they are comfortable, placing the patients arm on a Mayo stand to help, you may also want a small towel roll to help extend the wrist
For Median Nerve block:
- Locate the palmaris longus (PL) and the flexor carpi radialis (FCR) tendons
- you can have the patient flex the middle finger against resistance or pinch their thump and pinky together to help highlight these tendons
- some patients do not have PL but you can estimate its general location by going 5 mm medially to the FCR (~midpoint of the wrist)
- Prep the skin and drape it in sterile fashion
- Insert the needle perpendicular to the skin between the PL and FCR tendons 2-3 cm proximal to the distal crease of the wrist to a depth of 1-2cm
- aspirate and then inject 3-5cc of anesthetic then remove needle
- allow anesthetic to sit ~10 minutes prior to performing procedure
For Radial Nerve Block:
- locate the radial styloid and prep and drape area sterily
- inject 5cc of anethetic just above the radial styloid aiming medially
- extend infiltration laterally using an aditional 5cc of anesthetic
Complications
- infection
- hematoma
- nerve injury
- vascular injury
Source
emedicine