A conscious dog model for study of regional lung function.

Using a specially designed mask and steady-state administration of the short-lived radioactive gas 81mKr, we measured the distribution of the ventilation-perfusion ratio (VA/Q) in the lungs of normal conscious standing greyhound dogs during tidal breathing. This model allows measurement of regional lung function unaffected by anesthesia and mechanical ventilation. An assessment of the distribution of VA/Q in the lungs of normal greyhound dogs revealed that topographically, ventilation and blood flow are well matched in the conscious dog.