An arterial line (also art-line or a-line) is a thin

catheter In medicine, a catheter (/ˈkæθətər/) is a thin tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgical procedure. Cat ...

inserted into an

artery An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the p ...

Use

Arterial lines are most commonly used in

intensive care medicine Intensive care medicine, also called critical care medicine, is a medical specialty that deals with seriously or critically ill patients who have, are at risk of, or are recovering from conditions that may be life-threatening. It includes pro ...

and

anesthesia Anesthesia is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), ...

to monitor blood pressure directly and in real-time (rather than by intermittent and indirect measurement) and to obtain samples for

arterial blood gas An arterial blood gas (ABG) test, or arterial blood gas analysis (ABGA) measures the amounts of arterial gases, such as oxygen and carbon dioxide. An ABG test requires that a small volume of blood be drawn from the radial artery with a syringe ...

analysis. Arterial lines are generally not used to administer medication, since many injectable drugs may lead to serious tissue damage and even require amputation of the limb if administered into an

rather than a vein. An arterial line is usually inserted into the

radial artery In human anatomy, the radial artery is the main artery of the lateral aspect of the forearm. Structure The radial artery arises from the bifurcation of the brachial artery in the antecubital fossa. It runs distally on the anterior part of the ...

in the wrist, but can also be inserted into the

brachial artery The brachial artery is the major blood vessel of the (upper) arm. It is the continuation of the axillary artery beyond the lower margin of teres major muscle. It continues down the ventral surface of the arm until it reaches the cubital foss ...

at the elbow, into the

femoral artery The femoral artery is a large artery in the thigh and the main arterial supply to the thigh and leg. The femoral artery gives off the deep femoral artery or profunda femoris artery and descends along the anteromedial part of the thigh in the fe ...

in the groin, into the

dorsalis pedis artery In human anatomy, the dorsalis pedis artery (dorsal artery of foot) is a blood vessel of the lower limb. It arises from the anterior tibial artery, and ends at the first intermetatarsal space (as the first dorsal metatarsal artery and the deep pl ...

in the foot, or into the

ulnar artery The ulnar artery is the main blood vessel, with oxygenated blood, of the medial aspects of the forearm. It arises from the brachial artery and terminates in the superficial palmar arch, which joins with the superficial branch of the radial ar ...

in the wrist. A golden rule is that there has to be

collateral circulation Collateral circulation is the alternate circulation around a blocked artery or vein via another path, such as nearby minor vessels. It may occur via preexisting vascular redundancy (analogous to engineered redundancy), as in the circle of Wi ...

to the area affected by the chosen artery, so that peripheral circulation is maintained by another artery even if circulation is disturbed in the cannulated artery. Insertion is often painful; an anesthetic such as

lidocaine Lidocaine, also known as lignocaine and sold under the brand name Xylocaine among others, is a local anesthetic of the amino amide type. It is also used to treat ventricular tachycardia. When used for local anaesthesia or in nerve blocks, lidoc ...

can be used to make the insertion more tolerable and to help prevent

vasospasm Vasospasm refers to a condition in which an arterial spasm leads to vasoconstriction. This can lead to tissue ischemia and tissue death (necrosis). Cerebral vasospasm may arise in the context of subarachnoid hemorrhage. Symptomatic vasospasm or ...

, thereby making insertion of the arterial line somewhat easier.

References

{{Intensive care medicine Catheters Diagnostic intensive care medicine