Figure 3.

The shunting theory of sepsis accounts for the condition in which apparently adequate oxygen delivery is not successful in delivering oxygen to microcirculatory weak units that are shunted. This leads to an oxygen extraction deficit of these shunted units with raised levels of venous partial pressure of CO₂, lactate and gastric CO₂, whereas input oxygen delivery seems adequate. Vasodilation would be expected to recruit these shunted units by increasing the driving pressure to the microcirculation and possibly to these shunted units.