Arterial Cannulation


Arterial Cannulation, Arterial Line

  • Indications
  • Critically Ill Patient
  1. Serial Arterial Blood Gas monitoring (esp if >4 samples needed in 24 hours)
  2. Continuous Blood Pressure Monitoring
  3. Other hemodynamic monitoring parameters may be estimated electronically (based on wave form)
    1. Cardiac Output
    2. Stroke Volume
    3. Pulse Pressure Variation
  • Precautions
  1. Never use arterial catheters for medication or fluid infusions
  2. Monitor line continuously
    1. Alarms that would indicate open catheter (with blood loss)
    2. Inspect for ischemic limb or infection
      1. Remove catheter immediately if these occur
  3. Remove catheters as soon as they are no longer needed
  4. Must calibrate catheter and transducer first at heart level
  5. As with Blood Pressures in general, normal arterial pressure does not exclude hypoperfusion
    1. Compensatory Vasoconstriction may mask hypoperfusion until precipitous drop
    2. Use other measures (e.g. IVC Ultrasound for Volume Status) to further evaluate vascular status
  6. Abnormal pressure readings from catheter should be confirmed with manual Blood Pressure readings
    1. Waveform may be distorted by vascular and transducer changes
    2. Mean arterial pressure typically remains accurate despite waveform distortion
  • Preparation
  • Arterial Line Sites (in order of preference)
  1. Radial artery (preferred)
  2. Femoral artery (requires longer catheter)
  3. Axillary artery (requires longer catheter)
  4. Dorsalis pedis artery (less reliable reading in adults)
  5. Avoid Brachial artery cannulation (risk of distal hand ischemia)
  • Technique
  • Preparation for Wrist Arterial Cannulation
  1. Perform Allen Test to confirm collateral circulation
  2. Heparinize syringe
    1. Start with 10 cc Syringe with stopcock
    2. Draw up 3-5 ml of Heparinized saline (50 units/ml)
  3. Obtain IV catheter
    1. Needle of 18 or 20 gauge with plastic cannula
    2. Flush with Heparinized saline
  4. Position patients wrist and hand
    1. Patient dorsiflexes wrist over towel pad
    2. Tape palm and upper Forearm to arm board
  5. Clean radial entry site
    1. Povidone-Iodine solution (Betadine) scrub
    2. Alcohol scrub
  6. Local Anesthetic at entry site
    1. Small skin wheal (1-2 ml) of Lidocaine 2%
  • Technique
  • Placing Arterial Line
  1. Identify radial artery with gentle pressure
  2. Needle angled 45 degrees toward arm
  3. Enter skin just distal to palpated artery site
  4. Slowly advance needle until spontaneous blood enters
  5. Guide wire passed into artery
  6. Remove needle
  7. Advance flushed plastic cannula over top of guide wire
    1. Uses modified Seldinger technique
  8. Attach syringe of Heparinized saline
  9. Re-flush cannula with 2 cc Heparinized saline
  10. Turn Stopcock to seal artery
  11. Connect transducer and high-pressure infusion set
  12. Remove pad under wrist and secure arm board
  • Complications
  1. Arterial Thrombosis
    1. Risk increases with decreasing wrist circumference
    2. Risk increases rapidly in first 24 hours, than slowly
  2. Occult Hemorrhage
    1. Open Arterial Line can result in rapid blood loss
  3. Cerebral embolization
    1. Occurs with vigorous Flushing of radial catheters
    2. Gentle irrigation with 1-2 ml boluses should be used
  4. Localized infection
    1. Risk increases after 72 hours
    2. Remove catheter at earliest possible time
    3. Provide careful wound and dressing care
  • References
  1. Killu and Sarani (2016) Fundamental Critical Care Support, p. 93-114