Abstract
We investigated the effect of nebulized β-stimulant on regional ventilation-perfusion ratio and blood gas analysis. The change of PaO2 after β-stimulant administration by nebulization was small. PaO2 fell in approximately 50% of patients and rose in approximately 30% of patients after nebulization. These changes of PaO2 corresponded to the change of the distribution of ventilation-perfusion ratio which was measured by the steady state method of Kr-81m inhalation and infusion.
In the group in which PaO2 decreased after β-stimulant administration, the distribution of the ventilationperfusion ratio became less homogenous than the base pattern and the overperfusion area increased. This meant that the effect of A-V shunt increased following administration of β-stimulant nebulizer. On the other hand, the change of PaO2 correlated with alveolar ventilation.
We concluded that the change of PaO2 after administration of β-stimulant correlated with both the change of distribution of ventilation-perfusion ratio and the change of alveolar ventilation.
