Figure 17-37
Effects of changes in cardiac output (
) on the
O2
content of end-pulmonary capillary, arterial, and mixed venous blood
for a group of different transpulmonary right-to-left shunts. The magnitude of the
right-to-left shunt is indicated by the various numbered percent symbols for arterial
(solid line) and mixed venous (dashed
line) blood; the oxygen content of end-capillary blood is unaffected by
the degree of shunting. Note that a decrease in results in a greater decrease
in the arterial content of O2
the larger the shunt. (Redrawn
from Kelman GF, Nunn JF, Prys-Roberts C, et al: The influence of the cardiac output
on arterial oxygenation: A theoretical study. Br J Anaesth 39:450, 1967.)
