Under normal physiologic conditions, an increase in PCO2 causes a decrease in pH, which will increase minute ventilation and therefore increase alveolar ventilation to attempt to reach homeostasis. The higher the minute ventilation, the more exchange and loss of PCO2 will occur inversely.

How much does pH change with pCO2?

1. For an acute change in pCO2 of 10, the pH will change by 0.08. If all changes in pH can be accounted for by the change in pCO2, then the problem is an acute respiratory acidosis or alkalosis. If not, there is a metabolic component.

How does CO2 levels affect blood pH?

Respiratory acidosis occurs when the lungs can’t remove enough of the carbon dioxide (CO2) that the body produces. Excess CO2 causes the pH of your blood and other bodily fluids to decrease, making them too acidic.