Letters to the Editor

Abstract

Dr. Ivanhoe suggests the interesting possibility that pulmonary venoconstriction may be an important feature of the idiopathic respiratory distress syndrome. While our physiological studies are consistent with pulmonary vascular obstruction on either the pre-or postcapillary side, there is evidence that the major obstruction is precapillary. The small pulmonary arterioles in lungs of infants dying with respiratory distress have thick walls and small lumina. When we perfused these lungs in vitro with blood or plasma, very low flows were observed unless pressures in excess of 200 cm of water were applied.