96 Section III ■ Blood Sampling

Radial Artery Puncture (2) (Fig. 15.1)

1. Slightly extend supine wrist, avoiding hyperextension,

which may occlude the vessel.

2. Locate radial and ulnar arteries at proximal wrist crease

(Fig. 15.2).

a. Radial artery is lateral to flexor carpi radialis tendon.

b. Ulnar artery is medial to flexor carpi ulnaris tendon.

Fig. 15.1. Radial artery puncture.

F. Technique (See Procedures Website

for Video)

General Principles (1,2)

1. Transillumination may assist location of vessel (8) (see

Fig. 13.5).

2. Clean the site with povidone–iodine and alcohol.

3. Position needle for arterial puncture against direction

of blood flow.

a. Keep angle of entry shallow for superficial vessels at 15

to 30 degrees; use 45-degree angle for deeper artery.

b. Penetrate the skin first slightly proximal to the best

point of pulsation, and then puncture artery to minimize trauma to vessel, keeping bevel of needle up.

c. Apply gentle suction on syringe as soon as blood

flow is observed; maintain needle in same position

until all blood samples have been collected.

d. If no blood flow is obtained or blood flow ceases,

adjust depth of penetration or the angle of the needle. If resistance is encountered, withdraw needle

cautiously until blood returns. Be patient and

gentle—artery may spasm when needle is introduced, or with multiple attempts.

e. Use fresh needle and repeat skin preparation if withdrawal from skin is necessary.

4. Apply firm, local pressure for 1 to 3 minutes to achieve

complete hemostasis.

5. Inspect fingers for circulatory compromise (9,10).

Fig. 15.2. Anatomy of the major arteries of the wrist and hand.