Arterial line ("A line")

An arterial line (or "A line") is a sterile plastic tube (or cannula) that is inserted into an artery, usually in the wrist or groin. It allows accurate and continuous measurement of the patient's blood pressure. Blood samples are also taken from this line, to help us measure blood oxygen levels and make sure that the patient is receiving the right amount of support from the ventilator or breathing machine. An arterial line is usually stitched in, using a local anaesthetic, to avoid it becoming dislodged.

Are there any complications of having lines in?

The main risks are that the line or cannula can become kinked or dislodged. Other risks include bleeding, discomfort, inflammation and infection. The nurses will regularly check for problems, and lines are regularly changed to reduce the risk of infection. We aim to remove lines as soon as they are no longer neded, in order to reduce the risk of infection.