CARBON DIOXIDE AND THE WORK OF BREATHING*

Abstract

Ten dogs with opened chests and controlled respiration were ventilated with gases containing 0 - 20% CO2. Pulmonary compliance, viscous resistance, elastic and non-elastic work were calculated from measured trans pulmonary pressure, volume change and flow rate. pCO2 was determined in arterial blood. The increase in pCO2 was quantitatively related to decreased compliance and increased elastic work, resistance and viscous work. The increase in viscous work was 2 1/2 times that of the elastic work. Vagotomy prevented these changes.