A patient with sudden onset of hypoxemia, hypercapnia, and a normal bicarbonate value also has a normal P_(A-a)O₂ value. This would most likely be due to which one of the following?

Question

Quizplus · Accepted Answer

The normal P(A-a)O2 gradient suggests that the cause of hypoxemia is not due to a problem with oxygen transfer in the lungs, such as shunting or V/Q mismatch. Hypercapnic respiratory failure, characterized by elevated CO2 levels, can occur with normal oxygen transfer, leading to hypoxemia and hypercapnia without affecting the P(A-a)O2 gradient.

A Patient with Sudden Onset of Hypoxemia, Hypercapnia, and a Normal