Effects of breathing oxygen on cardiac and lung functions at highland piglets / 中国病理生理杂志

ABSTRACT

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.