Mechanisms of ventilation-perfusion mismatch and hemodynamic alterations in acute and chronic pulmonary embolism

Studies on gas exchange in pulmonary embolism are not numerous. A few of them have been performed in experimental animals . The methods employed comprise the determination of gas exchange parameters], including the physiologic dead space, and the multiple inert gas elimination technique]. Furthermore, not much effort has been made to relate topographical alterations of ventilation and blood flow, detected by external counting of radioactive tracers, to ventilation/perfusion eVA/o,.) disturbances responsible for impaired gas exchange in pulmonary embolism. This paper reports data on pulmonary gas exchange, VA/Q distribution by inert gas elimination, and regional lung function by ventilation and perfusion scan in human pulmonary embolism.