Where Is an Arterial Line Placed?

Arterial line placement or arterial cannulation is typically placed in the radial artery in the forearm or the femoral artery in the thigh.
Arterial line placement, or arterial cannulation, is typically placed in the radial artery in the forearm or the femoral artery in the thigh.
  • Arterial line placement, or arterial cannulation, is a commonly performed procedure, especially for patients in critical care and some anesthetic settings. Arterial line placement is done in children and adults. 
  • The most common site where an arterial line is placed is the radial artery that is in the forearm. This is because the radial artery lies superficially, and the anatomical location is constant, making it easily accessible. 
  • The second most common site for arterial cannulation is the femoral artery that is in the thigh. 
  • An advantage of the femoral artery is that the blood vessel is larger and has larger pulsations than those in the radial artery. With femoral artery insertion, there is a decreased risk of blood clot formation in the blood vessel or accidental displacement of the arterial line.

Why is an arterial line placed?

An arterial line is placed for

  • Preventing complications associated with repeated arterial puncture (pain and blood clots).
  • Continuous direct blood pressure (BP) monitoring. Intra-arterial BP measurement is more accurate than BP measurement by noninvasive means, especially in critically ill patients. Intra-arterial BP management allows the rapid recognition of BP changes compared with noninvasive methods of BP measurements.
  • Frequent blood sampling (arterial blood gas sampling).

Arterial line placement may also be indicated in patients


In the U.S., 1 in every 4 deaths is caused by heart disease. See Answer

How is arterial line placement done?

An arterial line procedure is performed by cardiologists, cardiac surgeons, thoracic surgeons, critical care medicine doctors, critical care surgeons, emergency medicine doctors, and pediatric emergency medicine doctors or registered nurses (RNs) who have additional training to insert arterial lines.

  • Arterial line insertion is usually done in the operation room (OR), emergency room (ER), or intensive care unit (ICU). 
  • The patient is made to lie down, so the doctor or nurse can access the blood vessel easily. 
  • The doctor/nurse cleans the site of cannulation with an antiseptic and may numb the area with a local anesthetic. 
  • An ultrasonography (USG)-guided placement is a better technique and may be used in a few cases. 
  • The doctor/nurse inserts a small tube (catheter) through the skin and into the artery. 
  • They then connect the catheter to a tubing filled with saline and a transducer device. 
  • The transducer helps measure the blood pressure.
  • There may be minimal discomfort, a feeling of pressure, a prick, or sting during insertion. 
  • This resolves quickly. Once the arterial line is in place, there is no pain or discomfort. 
  • Pain and sedative medications may be administered as needed.

What are the risks and potential complications of arterial line insertion?

Complications of arterial line insertion are rare, less than 1%. Some possible risks include:

  • Allergic reaction to local anesthesia
  • Bleeding
  • Blockage of the artery leading to reduced blood supply to the body tissues
  • Blood clots
  • Infection
  • Injury to the artery or surrounding tissue