Certified Transport Registered Nurse Certification Practice Exam

Increased respirations lead to changes in which of the following gases?

1. Increased PaCO2, Decreased pH

2. Decreased PaCO2, Increased pH

3. Increased PaCO2, Increased pH

4. Decreased PaCO2, Decreased pH

The correct answer is: Decreased PaCO2, Increased pH

Increased respirations, or hyperventilation, result in the expulsion of carbon dioxide (CO2) from the body through the lungs. When respiration rates are elevated, the body exceeds its metabolic rate for CO2 production, leading to decreased levels of carbon dioxide in the blood, which is indicated by a decrease in the partial pressure of carbon dioxide (PaCO2). As the levels of PaCO2 drop, the blood becomes less acidic, contributing to an increase in pH. This shift in blood chemistry can lead to a state known as respiratory alkalosis, characterized by a higher pH due to decreased carbon dioxide levels. Thus, in the context of increased respirations, the correct option emphasizes that there is a decrease in PaCO2 coupled with an increase in pH, which accurately reflects the physiological response of the body to hyperventilation.