Evaluation of pulse contour methods in calculating stroke volume from pulmonary artery pressure curve(comparison with aortic pressure curve)

The reliability of five equations in assessing stroke volume from pulmonary artery pressure curves were critically evaluated in six dogs and in six patients. To alter stroke volume, isoproterenol, dobutamine, propranolol, lactate Ringer solution and artificial pacing were employed in the animal study and diltiazem (a calcium blocker) in the human study. A good correlation was found between the calculated and measured stroke volume (r = 0.80-0.86 in the animal study and r = 0.94-0.96 in the human study). The assessment of stroke volume from the pulmonary arterial pressure curves using equations was as good as that from the aortic pressure curves calculated simultaneously. These results suggest that the five equations may be clinically applicable for assessing stroke volume in critically ill patients. The employment of pulmonary arterial pressure curves in assessing stroke volume may be more useful clinically since its recording can be carried out more safely than recordings of aortic pressure curves.