The “Effective” Pulmonary Collateral Blood Flow in Man1

Abstract

Anatomic observations have established that an extensive overgrowth of systemic arteries into the lung may accompany various types of heart and lung disease. The present study was designed to measure rate of blood flow through such vessels, in particular rate of collateral blood flow to the gas-exchanging surface of the lung ("effective"). For this purpose, the Fick principle; was applied to three groups of subjects; in each group, the application was modified to conform with the anatomic abnormality. Different rates of "effective" collateral blood flow were measured, ranging from zero in subjects with either carcinoma of the lung or recent occlusion of the left pulmonary artery, to approximately-normal values for pulmonary blood flow in some subjects with congenital atresia of a pulmonary artery. Intermediate values, up to 11/minute, were obtained in subjects with bron-chiectasis, long-standing ligation of a pulmonary artery, and idiopathic clubbing of the digits.