It is also a good measure for those needing intravenous fluid therapy, for instance post heart surgery, shock, and severe burns.

[3] General indications are: No study has definitively demonstrated improved outcome in critically ill patients managed with PA catheters.

In crude terms, this measurement compares left and right cardiac activity and calculates preload and afterload flow and pressures which, theoretically, can be stabilized or adjusted with drugs to either constrict or dilate the vessels (to raise or lower, respectively, the pressure of blood flowing to the lungs), in order to maximize oxygen for delivery to the body tissues.

A further set of calculations can be made by measuring the arterial blood and central venous (from the third lumen) and inputting these figures into a spreadsheet or the cardiac output computer, if so equipped, and plotting an oxygen delivery profile.

It can lead to arrhythmias, pseudoaneurysm formation or rupture of the pulmonary artery, thrombosis, infection, pneumothorax, bleeding, and other problems.

In 2005, a multi-center randomized controlled trial found no difference in mortality or length of stay in ICU patients who received pulmonary artery catheters, though it did find a 10% incidence of complications related to the procedure.

[8] Contrary to earlier studies there is growing evidence the use of a PA catheter (PAC) does not necessarily lead to improved outcome.

This interpretation of Adolph Ficks' formulation for cardiac output by time/temperature curves is an expedient but limited and invasive model of right heart performance.

Except during hypothermia and in severe sepsis, low mixed venous oxygen saturations are indication of inadequate hemodynamics.

The ability of the pulmonary artery catheter to sample mixed venous blood is of great utility to manage low cardiac output states.

Non-invasive echocardiography and pulse-wave cardiac output monitoring are concordant with (and much safer) if not better than invasive methods defining right and left heart performance.

The emergence of MRSA and similar hospital based catheter infections now clearly limits the utility of this type of invasive cardiac ICU intervention.