The Vitals: Indications for Arterial Line Placement

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Shyam Murali
Shyam Murali
Fellow in Trauma and Surgical Critical Care - University of Pennsylvania, Senior Editor -, Writer -, Saxophonist, EDM remixer, husband, puppy father, and new human father

The Pre-brief

Arterial lines are very commonly used in the ED, ICU, and OR settings. They have numerous advantages, but placement can be painful and these lines are not immune to complications (occlusion of arteries, bleeding, associated infections, and thromboembolic complications). Despite widespread use of arterial lines, there is no evidence that using them improves outcomes in the ICU. It is important to understand the indications for placing arterial lines in the ICU to avoid performing the procedure unnecessarily (there are many procedural indications as well, but these are typically done outside the ICU):

  • The obvious indication: need for continuous hemodynamic monitoring
      • Patients requiring vasopressor or anti-hypertensive infusions
      • Patients who need tight blood pressure control (stroke, spinal cord injury, etc.)
      • Patients who are peri-arrest; it can help determine if and when a patient is about to have cardiac arrest
  • The risky indication: need for frequent labs draws; repeated needle pokes for blood draws can make the patient start to feel like a pincushion
      • Be extremely cautious with this indication and consider very meticulously whether the patient really needs “frequent labs”; this may be reasonable in severe electrolyte imbalances, acidosis, etc.
      • Placing an art line for this indication is a quick way to phelbotomize the patient if you are not careful
      • While I was unable to find any direct research into this topic, it stands to reason that manipulation of the arterial tubing and repeated access of the blood draw port could increase the risk of infections
      • From a systems perspective, make sure that lab orders are discontinued when they are not needed, or consider not using scheduled labs at all
      • Ensure that your entire team is on the same page about exactly which labs are crucial
      • Just because a patient is intubated does not mean they need an arterial line; not all ventilated patients need daily ABGs
      • COVID-DENDUM: COVID patients who are being proned, more often than not, will receive arterial lines for ease of blood draws.
  • The lesser-known indication: consider it in morbidly obese patients.
    • The shape of the arm in some obese patients may prevent the BP cuff from giving accurate measurements3,4,5
    • There are special, conical BP cuffs that may be more accurate6

The Debrief

  • Carefully consider whether the patient in front of you truly needs an arterial line before placing one
  • Make sure your whole team is aware of exactly why the art line was placed
  • Despite widespread use of arterial lines, there is no evidence that using them improves outcomes in the ICU


  1. Zarbiv S, Pisani M. When Is a Peripheral Arterial Catheter (A-Line) Indicated in My ICU Patient?. CHEST 2018.
  2. Hambsch ZJ, Kerfeld MJ, Kirkpatrick DR, McEntire DM, Reisbig MD, Youngblood CF, Agrawal DK. Arterial Catheterization and Infection: Toll-like Receptors in Defense against Microorganisms and Therapeutic Implications. Clin Transl Sci. 2015 Dec;8(6):857-70. doi: 10.1111/cts.12320. Epub 2015 Aug 14. PMID: 26271949; PMCID: PMC4703511.
  3. Deranged Physiology. Indications and contraindications for arterial line insertion. 
  4. Anast N, Olejniczak M, Ingrande J, Brock-Utne J. The impact of blood pressure cuff location on the accuracy of noninvasive blood pressure measurements in obese patients: an observational study. Can J Anaesth. 2016 Mar;63(3):298-306. doi: 10.1007/s12630-015-0509-6. Epub 2015 Oct 16. PMID: 26475165.
  5. Araghi A, Bander JJ, Guzman JA. Arterial blood pressure monitoring in overweight critically ill patients: invasive or noninvasive? Crit Care. 2006;10(2):R64. doi: 10.1186/cc4896. PMID: 16630359; PMCID: PMC1550873.
  6. Hersh LT, Sesing JC, Luczyk WJ, Friedman BA, Zhou S, Batchelder PB. Validation of a conical cuff on the forearm for estimating radial artery blood pressure. Blood Press Monit. 2014 Feb;19(1):38-45. doi: 10.1097/MBP.0000000000000011. PMID: 24217368.


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