Neonatal Nurse Practitioner Practice Exam

What changes are observed during alkalosis regarding pH and CO2?

1. Decrease in pH and increase in CO2

2. Increase in pH and decrease in HCO3

3. Increase in pH and decrease in CO2

4. Decrease in pH and decrease in HCO3

The correct answer is: Increase in pH and decrease in CO2

In a state of alkalosis, the blood pH rises above the normal level (which is typically 7.35-7.45), indicating that the blood is more alkaline. This increase in pH is primarily due to a decrease in hydrogen ion concentration. Additionally, during respiratory alkalosis specifically, there is an increase in ventilation leading to a decrease in carbon dioxide (CO2) levels because CO2 is expelled from the body at a higher rate than it is produced. Thus, during alkalosis, you see an increase in pH because it becomes more alkaline, and at the same time, there is a decrease in CO2 levels as the body's respiratory system increases the rate of breathing. Together, these changes support the physiological processes in the body trying to correct the acid-base imbalance. The correctness of the given answer highlights these physiological changes and reflects the body’s compensatory mechanisms in response to an alkaline environment.