The uptake and elimination of halothane in dogs: A two or multicompartment system? II: Evaluation of wash-in and wash-out curves.

In 14 mongrel dogs wash-in and wash-out curves for halothane were obtained from measurements of arterial blood, mixed venous blood and end-tidal gas. From a certain point in the wash-in period the halothane concentration of arterial blood can be calculated from the halothane concentration in end-tidal gas and the blood-gas partition coefficient for halothane. Analysis of the curves shows that they are composed of two exponential components suggesting the presence of two body compartments. The question of a two-compartment system versus a multi-compartment system in discussed.