Arterial Line

An arterial line, also called an art-line or a-line, is a thin catheter inserted into an artery, most commonly used in intensive care medicine and anesthesia to monitor blood pressure directly and in real time, rather than by intermittent and indirect measurement, and to obtain samples for arterial blood gas analysis. Arterial lines are generally not used to administer medication, since many injectable drugs can cause serious tissue damage, even requiring amputation, if given into an artery rather than a vein. The line is usually inserted into the radial artery at the wrist, though it can also be placed in the brachial, femoral, dorsalis pedis or ulnar arteries, provided that collateral circulation exists so that blood flow to the affected area is maintained by another artery even if circulation in the cannulated artery is disturbed; insertion is often painful, so a local anesthetic such as lidocaine is commonly used to ease it and help prevent vasospasm.