Effect of Oxygen Breathing on Distribution of Pulmonary Blood Flow in Chronic Obstructive Lung Disease1, 2

摘要: In chronic obstructive lung disease, a major functional disturbance lies in maldistribution of ventilation the lungs. It has been postulated that, at least some patients, compensatory regional pulmonary vasoconstriction may occur poorly ventilated portions such lungs, thus reducing range ventilation-perfusion ratios and improving arterial oxygen tension. The evidence for this largely reduction tension or saturation that follow administration vasodilator drugs, as tolazoline (1, 2) aminophylline (3-5). suggested these drugs reverse pre-existing regions lungs leads to worsening ratio distribution fall Oxygen is powerful, nonspecific, agent. Pain, Read, Read (6) showed group patients with disease breathing was sometimes associated an increase carbon dioxide (Pac02 ) greater than be expected from any hypoventilation produced by oxygen. increases Pa002, not due diminished were also ventilationperfusion Analysis factors involved indicated this, turn, must reflect increased blood flow through breathing; is, there reversal patients. These conclusions based on comparisons Pa002 made when subject air after ten minutes. Some