Arterial catheters (also called intra-arterial catheters or A-lines) are common in critically ill patients. They can be used to obtain arterial blood for laboratory testing, and for direct measurement of blood pressure and cardiac output. However, insertion of an arterial catheter is an invasive procedure and complications can occur.
This topic will review the indications, insertion techniques, and complications of arterial catheterization. The use of arterial catheters to monitor blood pressure is also reviewed. Percutaneous arterial puncture and arterial blood gases (ABGs) are discussed elsewhere. (See "Arterial blood gases".)
Advantages of an indwelling arterial catheter include continuous access to arterial blood and the ability to continuously measure the blood pressure. As a result, arterial catheterization is indicated when:
●Frequent blood gases are necessary, such as with acute respiratory failure.
●The blood pressure must be monitored closely, such as during shock, major surgery, hypertensive emergency, or vasopressor therapy. This is particularly true if the blood pressure abnormality is acute or the blood pressure is labile.