Neonatal Nurse Practitioner Practice Exam

What does respiratory alkalosis represent in terms of acid-base balance?

1. Decreased ventilation-perfusion ratio

2. Increased alveolar ventilation

3. Increased retention of CO2

4. Increased loss of H+ ions

The correct answer is: Increased alveolar ventilation

Respiratory alkalosis is characterized by an increase in blood pH due to decreased levels of carbon dioxide (CO2) caused by hyperventilation. When an individual exhibits increased alveolar ventilation, there is a greater expulsion of CO2 from the body. CO2 is produced as a byproduct of metabolism and is normally exhaled during respiration. When ventilation exceeds the metabolic production of CO2, it leads to a reduction in the concentration of CO2 in the blood (hypocapnia) and subsequently raises the pH, resulting in respiratory alkalosis. In this context, the correct understanding captures how increased alveolar ventilation contributes to the disturbance in acid-base balance by causing a state where there is insufficient CO2 to balance the amount of H+ ions in the blood, leading to a rise in pH. This contrasts with a decreased ventilation-perfusion ratio, which generally indicates ineffective gas exchange and would not increase pH. Increased retention of CO2 would typically result in respiratory acidosis, and increased loss of H+ ions does not directly relate to the specific process of respiratory alkalosis induced by hyperventilation.