Question

What mechanisms produce hypercapnia and hypoxemia?

Answer 1

Hypercapnia is the condition of increased level of carbon dioxide in the blood. There are several causes to induce hypercapnia like lung disease, hypoventilation, or increased exposure in smoke that contain high carbon dioxide.

Oxygen is essential for the survival of life, hypoxemia is decrease in the partial pressure of oxygen in the blood. There are several mechanisms of hypoxemia such as V/Q mismatch, right-to-left shunt, diffusion impairment, hypoventilation, and low inspired PO₂. Ventilation/perfusion mismatch is most common mechanism of hypoxemia, which can be caused due to asthma, lung disease, pulmonary hypertension, COPD, cystic fibrosis etc.

Shunt is also another mechanism for the hypoxemia in which the blood from the right side of the heart enters to the left side without any exchange of gases. Diffusion limitation also responsible for the hypoxemia and it may be caused due to decrease in the lung surface area for diffusion of the gases, low alveolar oxygen, inflammation etc. Hypoventilation is inadequate ventilation for the removal of CO2.