| Abstrakt: |
Eleven patients anaesthetized with sodium thiopentone, tubocurarine and halothane and ventilated with constant volume intermittent positive pressure were the subjects of a study of the effects of changes in inspiratory flow rate on alveolar-arterial oxygen difference, physiological shunt and physiological deadspace. The physiological deadspace increased significantly when inspiratory flow rate was raised above 25 l./min, but no change was demonstrable in venous admixture effect. The magnitude of the values derived and the possible mechanisms involved are discussed. The existence of a series of negative feed-back loops, with respect to the reduction of alveolar-arterial oxygen gradient, by intermittent positive pressure, is suggested. |
