Neonatal Nurse Practitioner Practice Exam

What compensatory response is generally seen in respiratory acidosis?

1. Decrease in CO2 and HCO3

2. Increase in CO2 and decrease in HCO3

3. Increase in CO2 and HCO3

4. Decrease in HCO3 and increase in pH

The correct answer is: Increase in CO2 and HCO3

In the context of respiratory acidosis, the body primarily responds through metabolic compensation. When there is an increase in carbon dioxide (CO2) due to inadequate ventilation, this elevation in CO2 leads to an increase in hydrogen ions (H+) in the blood, causing a decrease in pH (a condition known as acidosis). To counteract this acidotic state, the kidneys will compensate by increasing the reabsorption of bicarbonate (HCO3-), which acts as a buffer for the excess hydrogen ions. As a result, the bicarbonate levels in the blood rise in an attempt to neutralize the acidity and restore the blood pH to a more normal range. Therefore, in respiratory acidosis, you would expect to see an increase in both CO2 (due to hypoventilation) and bicarbonate (as a compensatory response by the kidneys). This understanding aligns with the choice that indicates both CO2 and HCO3 levels increase, reflecting the physiological strategy the body employs to achieve homeostasis during episodes of respiratory acidosis.