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  • 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

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  • Allen test indicates that collateral circulation is compromised.

  
  

  • Circulatory defects.

  
  

  • Sampling area is infected.

Relative

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  • 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.

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  • 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.