[The hemodynamic and oxygen dynamic effects of mechanical ventilation in chronic cor pulmonale]

Observation by using Swan-Ganz catheter on hemodynamic and oxygen dynamic changes before and after assisted volume controlled mechanical ventilation (MV) was carried out in 11 cases of chronic cor pulmonale complicated with pulmonary encephalopathy. Pulmonary vascular resistance and pulmonary artery pressure were significantly decreased by the relief of hypoxia pulmonary vasoconstriction after MV. Because of the relax of sympathetic tension, the heart rate, arterial blood pressure, pulmonary capillary wedge pressure and central venous pressure reduced simultaneously. Left and right ventricular stroke work decreased after MV, without significant change in cardiac output. Venous admixture (Qs/Qt) was markedly reduced by MV and oxygen supply-demand ratio raised. It is thus shown that marked improvement of hemodynamic and oxygen dynamic status can be induced by mechanical ventilation at an opportune moment.