Figure 5-9 Proportional increases in alveolar ventilation (VA) and cardiac output (Q) increase the rate at which the alveolar concentration of anesthetic/concentration of inspired anesthetic (FA/FI ratio) rises. The effect is relatively small if the increase in cardiac output is distributed proportionately to all tissues (i.e., if cardiac output is doubled, all tissue blood flows are doubled). The greatest effect occurs with the most soluble anesthetic. (Adapted from Eger EI II, Bahlman SH, Munson ES: Effect of age on the rate of increase of alveolar anesthetic concentration. Anesthesiology 35:365–372, 1971.)