What is respiratory compensation for metabolic alkalosis?

• A. Hypoventilation to retain carbon dioxide
• B. Hyperventilation to expel carbon dioxide
• C. Increased hydrogen ion excretion
• D. Decreased renal function

Answer: (A)

Respiratory compensation for metabolic alkalosis involves hypoventilation, which is the body's attempt to correct the alkalotic state by retaining carbon dioxide (CO2). In a metabolic alkalosis situation, there is an increase in blood pH due to either excess bicarbonate or loss of hydrogen ions. To counteract this increase in pH, the respiratory system decreases the rate of ventilation, leading to CO2 retention. As CO2 levels rise, it increases the concentration of carbonic acid in the blood, which can help lower the pH back toward normal levels. This physiological response is a critical mechanism for maintaining acid-base balance in the body.

The other options do not align with the body's compensatory mechanisms for this condition. Hyperventilation, for example, would decrease CO2 levels and further increase alkalosis, while increased hydrogen ion excretion and decreased renal function relate more to renal compensation rather than respiratory compensation.