Model simulation of expired CO2 from its alveolar distribution in parallel and series models

The CO 2 model of Scherer (J. Appl. Physiol. 64:1022, 1988) is here applied to the 7 regions model of Jeng et al (Ann. Biomed. Eng. 28:453, 2000). While Scherer et al ended up with an alveolar CO 2 concentration of 3.1% and used a pulmonary blood flow of 100 mL/s, we applied West concept of less CO 2 and blood flow at the apex. The alveolar CO 2 concentrations and the pulmonary blood flow at the apex and base of the lung were: 2.6% and 4.4%; 1.2 mL/s and 41mL/s, respectively. The anatomical model of Weibel is scaled for each region The results are on the figure. Although the curves are similar, our curve shows a larger dead space and less slope of phase 3. The base of the lung contributes more to the onset of CO 2 in the capnogram. Supported in part by ONG‐Centro de Enseñanza, Investigación y Servicios.