Pulmonary Air Embolization in the Dog: II. Evidence and Location of Pulmonary Vasoconstriction

Abstract

The effect on pulmonary hemodynamics of balloon occlusion versus air embolizations of one pulmonary artery was compared. Only small modifications were observed on balloon occlusion. On unilateral air embolization, pulmonary arterial pressure was doubled, intrapulmonary venous and left atrial pressure was almost unchanged, pulmonary blood flow decreased moderately, and aortic pressure fell briefly. All changes disappeared within 15 minutes. As the mechanical obstruction of a balloon does not entail any marked changes, the profound effects of unilateral embolization cannot be explained by mechanical reasons. A concomitant pulmonary Vasoconstriction, also in the contralateral lung, must be present, probably on the arterial side of the pulmonary capillaries.