Role of pulmonary vascular resistance measurements in preoperative evaluation of candidates for pulmonary resection.

Pulmonary function tests (PFT), arterial blood gases (ABG), lung scanning, and pulmonary artery balloon occlusion with measurement of pulmonary vascular resistance (PVR) have all been used for preoperative evaluation of pulmonary function. These tests, however, do not always accurately predict tolerance to lung resection. We have evaluated a new technique which promises to increase the accuracy of preoperative evaluation of pulmonary function. Utilizing a balloon flotation catheter, we measured PVR at varying cardiac outputs. Forty-five patients underwent this study without morbidity or mortality. Five of 30 patients who subsequently underwent pulmonary surgery died of respiratory failure. All of these deaths were from the high-risk group as determined by PVR. Only one of the five had been judged to be at high risk by PFT and ABG. This technique has the advantages of low morbidity and simplicity and should be especially helpful in the evaluation of those patients who have borderline pulmonary function as determined by the more standard tests.