Wrist Block

Question 1

What three nerves can be selectively blocked at the

wrist?

Answer 1

Radial, median, and ulnar
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1115.

Question 2

How well do blocks performed at the wrist prevent

movement of the hands and fingers?

Answer 2

Wrist blocks are sufficient for anesthesia of the fingers and
hand, but if motor block is necessary for the procedure, it is best
to choose another anesthetic technique.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1115.

Question 3

How is the median nerve blocked at the wrist?

Answer 3

2-5 mL of local anesthetic is injected in the carpal tunnel using a
short, B-bevel needle between the long palmar muscle and the
radial flexor muscle proximal to the proximal crease of the
wrist. An additional 2-3 mLs are injected as the needle is
withdrawn from the carpal tunnel.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1116.

Question 4

What muscles of the hand does the median nerve

supply?

Answer 4

The median nerve provides motor innervation to the muscles of
the thenar eminence, the forearm flexors, and the lumbrical
muscles of the first and second fingers.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 836.

Question 5

How would you perform an ulnar nerve block at the

wrist?

Answer 5

This block can be performed via the injection of 2-4 mL of local
anesthetic on the radial side of the ulnar flexor muscle at the
wrist, just lateral to the ulnar artery.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1115.

Question 6

What muscles of the hand are supplied by the ulnar

nerve?

Answer 6

The ulnar nerve supplies motor innervation to all of the small
muscles of the hand with the exception of the lumbricals of the
first and second finger and the muscles of the thenar eminence.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 837

Question 7

What areas of the hand receive sensory innervation

from the ulnar nerve?

Answer 7

The ulnar nerve provides sensory fibers to the ulnar side of the
hand, the little finger, and the ring finger.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 837.

Question 8

How is a radial nerve block at the wrist performed?

Answer 8

The most common approach is to inject 3-5 mL of local
anesthetic as a field block along the extensor pollicis longus
tendon at the base of the thumb and then inject another 1 mL at
a right angle across the ‘anatomical snuffbox’.
Butterworth JF, Mackey DC, Wasnick JD. Morgan & Mikhail’s
Clinical Anesthesiology. 5th ed. New York, NY: McGraw-Hill;
2013: 998-999.

Question 9

What sensory areas of the hand does the median

nerve supply?

Answer 9

The median nerve innervates the palm and ventral apsect of the
fingers as well as the nail beds of the thumg, index finger,
middle finger, and radial half of the ring finger.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 836.

Question 10

What areas of the hand receive sensory innervation

from the radial nerve?

Answer 10

The radial nerve provides sensory innervation to the lateral
aspect of the dorsum of the hand and to the proximal thumb,
index, and middle fingers as well as the lateral half of the ring
finger.
Longnecker DE, Newman MF, Brown DL, Zapol WM.
Anesthesiology. 2nd ed. New York: McGraw-Hill; 2012: 836.