Which pH level represents respiratory alkalosis?

• A. pH 7.30
• B. pH 7.50
• C. pH 6.80
• D. pH 7.20

Answer: (B)

Respiratory alkalosis is characterized by an increased pH level due to a decrease in carbon dioxide (CO2) in the blood, often resulting from hyperventilation or other conditions that lead to increased respiration. A normal arterial blood pH ranges from approximately 7.35 to 7.45. When the pH rises above this range, specifically exceeding 7.45, it indicates alkalosis.

In this context, a pH level of 7.50 signifies that the blood is more alkaline than normal, aligning with the definition of respiratory alkalosis. The increased pH reflects that the bloodstream has too little CO2, usually due to excessive release of CO2 during rapid or deep breathing. Therefore, this pH level directly correlates with the symptoms and biochemical changes associated with respiratory alkalosis.

The other pH levels presented either signify acidosis (lower than 7.35) or are still within the normal range but not elevated enough to indicate alkalosis. Thus, the pH of 7.50 distinctly indicates a state of respiratory alkalosis.