Question 11.1

What are the major advantages, disadvantages and complications of radial, brachial and femoral arterial lines for monitoring arterial pressure in a critically ill patient? Include in your answer the general complications of all sites as well as complications that are site specific.    (50% marks)

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College answer

Not available.


This is a well worded and highly relevant question that should form a part of the revision process for future candidates, because - though it may never be repeated again - the clinical importance of the subject matter transcends its exam importance. In other words, you need to know this stuff to be a good intensivist, and not just to pass the exam.

The detailed discussion of site selection in arterial line placement for some reason ended up in the First part Exam revision notes, even though there are no First Part Exam revision questions on this topic. Reasons for why it remains there are largely related to the indolence of the author. 

The best layout for this thing would probably be a table with this sort of structure:

Site Radial Brachial Femoral
  • Easily accessible even during surgery
  • Generous collateral circulation
  • Easily compressed
  • No collateral damage (not surrounded by delicate structures)
  • Does not restrict patient movement
  • Large and proximal: more accurately reflective of central arterial pressure
  • Much larger than the radial, and therefore easier to access and palpate
  • Easily compressible
  • Largest and most proximal
  • Most accurate reading of central arterial pressure (least affected by pulse wave amplification and peripheral vascular disease)
  • Easily palpated 
  • Distal enough to be accessible even during CPR
  • Distal; pulse amplification makes the systolic and diastolic less accurate
  • A highly mobile site; can easily kink or dislodge
  • Small; may be difficult to access
  • Subject to considerable anatomical variation
  • Difficult to access during surgery or CPR
  • End-artery; i.e. no collateral circulation (theoretical increase in the risk of limb ischaemia)
  • Right next to the median nerve
  • More likely to kink and occlude with patient arm movement
  • Potential for retroperitoneal haematoma, which is not compressible
  • Potential for through-and-through puncture of the femoral vein, resulting in an AV fistula
  • Theoretically, a higher risk of infection
  • Makes it challenging to mobilise patients
  • Cerebral embolization
  • Peripheral neuropathy
  • High risk of thrombotic complications
  • Median nerve damage
  • Cerebral embolization
  • Retroperitoneal haematoma
  • Abdominal visceral injury
  • Arteriovenous fistula

General complications for all sites

  • Pain and swelling
  • Accidental dislodgement
  • Thrombosis
  • Embolization
  • Haematoma
  • Haemorrhage
  • Limb ischemia
  • Catheter-related infection including bacteremia
  • Iatrogenic blood loss from frequent sampling
  • Pseudoaneurysm
  • Heparin-induced thrombocytopenia (if heparin is used in the flush bag)


Lee-Llacer J, Seneff, M. "Chapter 3: Arterial line placement and care." In: Irwin and Rippe's Intensive Care Medicine, 7th Edition.  New York: Little, Brown (2007): 36-47.

Pauca, Alfredo L., et al. "Does radial artery pressure accurately reflect aortic pressure?." Chest 102.4 (1992): 1193-1198.

Russell, James A., et al. "Prospective evaluation of radial and femoral artery catheterization sites in critically ill adults." Critical care medicine 11.12 (1983): 936-939.

Scheer, Bernd Volker, Azriel Perel, and Ulrich J. Pfeiffer. "Clinical review: complications and risk factors of peripheral arterial catheters used for haemodynamic monitoring in anaesthesia and intensive care medicine." Critical Care 6.3 (2002): 199.

Thomas, Frank, et al. "The risk of infection related to radial vs femoral sites for arterial catheterization." Critical care medicine 11.10 (1983): 807-812.

Chang, Cherylee, et al. "Air embolism and the radial arterial line." Critical care medicine 16.2 (1988): 141-143.

Durie, M., U. Beckmann, and D. M. Gillies. "Incidents relating to arterial cannulation as identified in 7525 reports submitted to the Australian Incident Monitoring Study (AIMS--ICU)." Anaesthesia and intensive care 30.1 (2002): 60.

Gurman, Gabriel M., and Shelly Kriemerman. "Cannulation of big arteries in critically ill patients." Critical care medicine 13.4 (1985): 217-220.

Russell, James A., et al. "Prospective evaluation of radial and femoral artery catheterization sites in critically ill adults." Critical care medicine 11.12 (1983): 936-939.

Wilkins, R. G. "Radial artery cannulation and ishaemic damage: a review." Anaesthesia 40.9 (1985): 896-899.

Smoller, Bruce R., and Margot S. Kruskall. "Phlebotomy for diagnostic laboratory tests in adults." New England Journal of Medicine 314.19 (1986): 1233-1235.

Abide, Aimee M., and Heather H. Meissen. "Arterial Line Access and Monitoring." Interventional Critical Care. Springer, Cham, 2021. 97-114.