Abstract
A mathematical analysis was developed to describe the relationship between physiological dead space and ventilation-perfusion abnormalities in a 2-compartment lung model. The model predicts that CO2 elimination is optimally efficient only when the ventilation-perfusion ratios are identical in both compartments. The physiological dead space-to-tidal volume ratio tends to remain constant during passive hyperventilation and decreases during exercise. Good agreement is found between the present study and the classical graphical analysis when the basic assumptions are similar.