In metabolic alkalosis, which of the following statements is true regarding CO2 content and pH?

• A. CO2 content elevated, pH decreased
• B. CO2 content decreased, pH elevated
• C. CO2 content elevated, pH elevated
• D. CO2 content decreased, pH decreased

Answer: (C)

In metabolic alkalosis the primary abnormality is an increase in bicarbonate, which raises the blood pH (alkalemia). To partially compensate, the respiratory system lowers ventilation to retain carbon dioxide, so CO2 content in the blood rises. This combination—elevated CO2 with elevated pH—fits metabolic alkalosis, where the body tries to bring pH back toward normal by increasing CO2, even though the pH remains high. The other patterns would reflect different situations (elevated CO2 with a lowered pH would indicate a mixed or different disorder, and decreased CO2 with an elevated pH wouldn't fit metabolic alkalosis).