Arterial Catheterization


INDICATIONS
  • Need for frequent monitoring of arterial blood gases
  • Need for continuous BP monitoring or inability to use indirect blood monitoring.
  • Need for use of vasoactive agents/inotropes
CONTRAINDICATIONS
  • Strict: Inadequate circulation to the extremity, Raynaud syndrome, Buerger disease, full-thickness burns
  • Relative: Patient on anticoagulants, coagulopathy, overlying cellulitis, partial thickness burns, inadequate collateral flow
TECHNIQUE
  • Standard sterile technique should be used and when possible, local anesthesia.
  • The radial, brachial, femoral, axillary, and ulnar arteries are usual sites for arterial puncture.
    • Pediatric sites include the dorsalis pedis, temporal arteries, and umbilical artery in newborns.
  • Allen's test is performed prior to radial artery cannulation to ensure collateral flow from ulnar artery.
  • Cannulation is usually placed with an over-the-needle catheter with or without a guidewire.
    • Larger vessels, such as femoral, always use needle puncture of the artery followed by the catheter placed over a guidewire (Seldinger technique).
  • The arterial pulsation is palpated with the index and middle fingers and the vessel course identified. The skin is punctured distal to the palpated pulse under the index finger. The needle is advanced slowly at a 30 angle with the skin. For larger arteries, the Seldinger/guidewire technique is used to cannulate the vessel.
  • Ultrasound or handheld Doppler can be used to assist in cannulation.
     
COMPLICATIONS
  • Bleeding, thrombosis leading to ischemia, infection
INTERPRETATION OF RESULTS
  • Once in the artery, the syringe plunger for blood gas collection should rise on its own due to arterial pressure.
  • The arterial wave form has a distinctive dicrotic notch on the down slope, caused by the closure of the aortic valve.