Calculation of systemic blood flow with pulmonary artery thermistor probe.

A simple thermodilution technique is described for determining systemic blood flow with right atrial and left atrial catheters and a pulmonary arterial thermistor probe. Injections of cold water into the atrial catheters provide computer display readings that permit direct calculation of systemic blood flow. The method is convenient for determining systemic blood flow in postoperative patients with a residual left-to-right shunt.