吸氧对高原动物心和肺功能的影响

我们观察了9只高原猪吸氧后的心肺功能变化。高原猪吸入纯氧后,右室收缩压、右室dp/dt max、肺动脉压和肺血管阻力明显降低,但左室dp/dt max、心指数、主动脉压和外周阻力无明显变化。这些结果提示肺血管收缩在慢性缺氧性肺动脉高压的发生中起重要作用。吸入纯氧后右室dp/dtmax下降,这表明慢性缺氧可致右室功能增加而肺分流率下降,提示高原幼猪存在肺通气/灌流不均。

Effects of breathing oxygen on cardiac and lung functions at highland piglets

The response of breathing 100% oxygen was studied in 9 anesthetized piglets, born and living at 3658m high altitude. After breathing pure oxygen at highland piglets right ventricular systolic pressure, dp/dt max of the right ventricle, stroke index, pulmonary vascular resistance and pulmonary arterial pressure were decreased obviously, but no significant changes were seen in the dp/dt max of left ventricle and cardiac index, peripheral vascular resistance and aortic pressure. These results suggested that the main factor responsiable for the increase in pulmonary resistance of highland piglets was hypoxic vasoconstriction. Breathing pure oxygen decreased dp/dt max of right ventricle, it appeared to show that chronic hypoxia might augment the right ventricular performance. The percent physiologic shunt was decreased by the inspirated pure oxygen. This fact implied that VA/Q mismatching occurred in highland piglets.