In respiratory alkalosis, which statement about ventilation is correct?

• A. The ventilation rate is increased.
• B. The ventilation rate is decreased.
• C. The bicarbonate level is decreased.
• D. The oxygen saturation decreases.

Answer: (A)

In respiratory alkalosis, faster or deeper breathing lowers the carbon dioxide level in the blood. CO2 is acidic when dissolved in blood, so blowing it off reduces hydrogen ion concentration and raises pH. That makes the statement about increasing ventilation the correct one. If ventilation were reduced, CO2 would build up and cause acidosis instead, not alkalosis. Oxygen saturation generally stays normal unless there’s another problem, so a decrease isn’t a defining feature. Bicarbonate can fall over time as the kidneys compensate for the alkalosis, but that’s a secondary effect, not the direct result of the ventilation change.