• Use smallest gauge needle to minimize arterial
• Hold pressure over puncture to prevent hematoma formation and
• The radial artery and the femoral artery are the preferred sites
for arterial puncture.
• If the pulse is hard to palpate, use Doppler and mark the location.
• In small infants, the radial artery may be located by transillumination.
• The Allen test involves the following:
• Localizing and assessing the radial pulse.
• Encircling the patient’s wrist with your hand and elevating
• Applying occlusive pressure on the radial and the ulnar arteries.
• Releasing the ulnar artery and continuing to apply occlusive
pressure on the radial artery.
• Monitoring palmar blush.