Special Operations Forces Medical Handbook

5-165

carpi ulnaris tendon and medial to the ulnar artery. This artery can be palpated with the wrist in
flexion.

4. At 1-1.5 cm in depth, slowly inject up to 5 mls of local anesthetic solution.


5. Withdraw the needle to the subcutaneous tissue and redirect the needle laterally around the ulnar
   aspect of the flexor carpi ulnaris, injecting an additional 5 mls of local anesthetic solution as you
   proceed. This will block the dorsal branch of the ulnar nerve laterally.

What Not To Do: See IIIb & IIIc
Contraindications: Ulnar nerve blocks should be avoided when significant paresthesia can be elicited
easily by palpating the nerve.

b. Median Nerve Block at the Wrist (Figure 5-35)

What To Do:

1. Assemble equipment.


2. Prep area.


3. Have the patient flex their wrist against resistance to identify the palmaris longus
   tendon. If present, insert a 25 or 27 gauge needle just lateral to the tendon. If the
   palmaris longus is absent, insert the needle 1 cm medial to the ulnar border of flexor
   carpi radialis tendon. Insert the needle past the flexor reticulum, which is indicated by increased

Ulnar Nerve Block, Medial Approach

Figure 5-34