Arterial Line


  • Continuous direct arterial blood pressure monitoring (i.e. refractory shock on pressors, hypertensive emergency, high risk surgery)
  • Frequent arterial blood draws (example: ARDS protocol, severe hypoxia)
  • Failure of indirect blood pressure monitoring (unreliable cuff pressure)


  • Absolute: absent pulse, Buerger’s disease (thromboangiitis obliterans), full-thickness burn over site, inadequate circulation to extremity (ischemic PVD), Raynaud syndrome
  • Relative: anticoagulation/coagulopathy, atherosclerosis, inadequate collateral flow, partial-thickness burn at cannulation site, previous surgery in area, synthetic vascular graft, infection at/near site


(Crit Care Review 2002:

  • Common: temporary occlusion of radial artery (up to 35%), hematoma (~15%)
  • Uncommon (<1%): permanent thrombosis/ischemia, AV fistula, pseudoaneurysm, nerve injury, air embolus, compartment syndrome


  • Radial arterial line kit (should include arterial needle, catheter, wire, lidocaine and syringe)
  • Chlorhexadine, small drape, sterile gown and gloves, mask with splash guard, extra sponges, sterile saline flush, tegaderm.


  • Informed consent
  • Timeout
  • Perform Allen test
  • Identify radial artery site
  • Dorsiflex patient wrist and secure to wrist board or rolled up towel with tape
  • Clean and drape sterile field

Insertion of radial arterial catheter

  • Anesthetize the insertion site with 1% lidocaine, make a small wheal
  • While gently palpating radial artery, insert radial artery needle in the skin just distal to the palpated artery, advance until pulsatile blood returns
  • Over the wire (Seldinger)
    • Advance the wire through the needle into the artery
    • Remove the needle while keeping the wire in the artery
    • Advance the catheter over the wire
    • Remove guide wire
  • Over the needle
    • Once you see the flash, advance the needle slightly further, then lower the angle to 10-15 degrees and advance the catheter over needle
    • Apply proximal pressure and remove the needle while keeping the catheter in place
  • Connect the catheter to the transducer system
  • Secure the catheter in place with suture and apply dressing over catheter
  • Check distal perfusion
  • Document procedure note
  • Log your procedure in Med Hub


  • If you have difficulty locating the artery, use a doppler probe covered in a sterile glove to locate the artery.
  • If you think you’ve entered the artery but are not getting pulsatile flow, your needle may be clogged and needs to be flushed with sterile saline.
  • Use the sonosite or ultrasound to guide line placement.
  • Switch from the Arrow to Cook kit.
  • Switch locations.
  • Call your fellow!