Arterial line

From ArticleWorld

An arterial line is a thin plastic catheter inserted into a peripheral artery. The catheter is attached to a piece of medical equipment that continuously measures the patient’s blood pressure wave in real time, eliminating the need for intermittent blood pressure monitoring. An arterial line is commonly used in intensive care settings and on very ill individuals.

Technique

An arterial line is generally placed in the brachial artery at the level of the elbow or in the radial artery on the inner aspect of the wrist. Using sterile technique, a hollow needle is inserted in the artery after feeling for the artery’s “pulse”. The needle is directed toward the upper arm.

Once cannulating (inserting into the hollow of) the needle, a long thin wire is placed into the end of the hollow needle, passing completely through the needle and into the artery. The needle is removed, leaving only the wire in place. A plastic catheter is inserted over the wire and into the hole in the artery that the wire is entering. The catheter is inserted up to its “hub” or distal end and fixed into place. Finally the wire, which was acting solely as a guide wire, is removed and the catheter is connected to the monitoring machine.

Monitoring

The arterial line is contiguous with the patient’s artery and therefore carries the same pressure. This is recorded on a monitor in a wave fashion noting the peaks (the systolic pressure) and the valleys (the diastolic pressure) in the arterial system of the patient.