• • Collection of arterial blood for blood gas analysis to manage cardiopulmonary disorders and maintain acid-base balance.

  • Collection of arterial blood when unable to sample venous blood to help manage fluid and electrolyte imbalance.

Absolute

• • Allen test indicates that collateral circulation is compromised.

  • Circulatory defects.

  • Sampling area is infected.

Relative

• • Coagulation abnormalities, such as hypercoagulability or hypocoagulability.

  • Patient has disease associated with hypercoagulability or hypocoagulability.

  • Hematoma at site.

  • Anatomic abnormalities in limb.

• • Gloves.

  • 23-gauge or smaller butterfly needle.

  • 1-mL heparinized syringe for blood gas sampling.

  • Syringes for blood sampling.

  • Disinfectant (povidone-iodine, chlorhexidine, and alcohol) swabs.

  • Sterile gauze pads.

  • Topical anesthetic.

• • Ischemia.

  • Hematoma.

• • Use smallest gauge needle to minimize arterial trauma.

  • Hold pressure over puncture to prevent hematoma formation and bleeding.

  • 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 the hand.

    • 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.