Advanced Patient Assessment Practice Exam

Which of the following is true regarding hypoventilation?

1. It increases PaCO2 levels

2. It decreases PaCO2 levels

3. It has no effect on PaCO2 levels

4. It always leads to alkalosis

The correct answer is: It increases PaCO2 levels

Hypoventilation refers to a reduced rate or depth of breathing, which directly affects the gas exchange process in the lungs. When someone hypoventilates, there is not enough fresh air entering the alveoli, which results in a decreased expulsion of carbon dioxide (CO2) from the bloodstream. As a result, the partial pressure of carbon dioxide in arterial blood, known as PaCO2, rises. This increase in PaCO2 can lead to respiratory acidosis if it becomes significant, as the accumulation of CO2 increases acidity in the blood. This physiological response highlights the connection between respiratory function and the body's carbon dioxide levels. In contrast, other options imply that hypoventilation either decreases PaCO2 levels or has no effect, which does not align with the well-understood mechanics of gas exchange in the respiratory system. The statement that hypoventilation always leads to alkalosis is also misleading, as hypoventilation typically results in acidosis rather than alkalosis. Understanding these principles is crucial for identifying and managing respiratory imbalances in clinical practice.