Effect of Gram-Negative Endotoxin on Pulmonary Circulation

Publisher Website
Google Scholar
Abstract
Effects of endotoxin on the pulmonary hemodynamics of dogs and cats have been studied in intact animals, open chest animals with and without control of cardiac output by an extracorporeal venous reservoir—pump system, and in isolated perfused continuously weighed lungs. Pulmonary artery pressure increased without a rise in left atrial pressure in all preparations following the injection of endotoxin. Pulmonary artery wedge and small pulmonary vein pressures uniformly increased. Total pulmonary vascular, pulmonary arterial and pulmonary venous resistances were calculated in five perfused lungs. The absolute increase in pulmonary venous resistance was greater than in the arterial resistance in four of the five studies and was relatively greater in every instance. There was a consistent increase in lung weight associated with these hemodynamic changes. Analysis of the determinants of lung weight changes has provided evidence to support the conclusion that the pulmonary vascular response to endotoxin administration is characterized predominantly by constriction of pulmonary venules and/or small veins.