Gas exchange after autologous pulmonary embolism in dogs

Abstract

The ventilatory and arterial blood gas responses to serum-induced thrombi embolized to the pulmonary circulation of the dog have been measured. An increase in rate and minute volume of ventilation independent of the extent of the pulmonary artery obstruction were almost invariably observed. The release of thrombi to the lungs was associated with an arterial-alveolar CO₂ tension difference that was dependent on the extent of arterial obstruction. Significant decreases in arterial O₂ saturation occurred in animals with massive embolization in the presence of a total minute and alveolar ventilation significantly greater than control values. Failure of arterial O₂ concentration to rise to control levels after inhalation of 99.6% O₂ indicated that emboli of the dogs' own blood produced a perfusion defect consistent with a right to left shunt. Submitted on November ₂1, 1960