Base excess positive values most closely indicate which condition?

Base excess positive values most closely indicate which condition?

• A. Primary metabolic alkalosis
• B. Primary metabolic acidosis
• C. Primary respiratory alkalosis
• D. Primary respiratory acidosis

Answer: (A)

Base excess shows how much base is present beyond what’s needed to normalize pH; a positive value means there is an excess of base (or a deficit of acid) in the blood. This is the hallmark of a metabolic alkalosis, where bicarbonate levels are elevated and the pH is high. Metabolic acidosis would drive base excess negative because bicarbonate is consumed to neutralize the excess acid. Primary respiratory disorders alter CO2; any changes in base excess there come from the body's metabolic compensation, not from the primary abnormality. So a positive base excess most closely points to a metabolic alkalosis.

Base excess shows how much base is present beyond what’s needed to normalize pH; a positive value means there is an excess of base (or a deficit of acid) in the blood. This is the hallmark of a metabolic alkalosis, where bicarbonate levels are elevated and the pH is high. Metabolic acidosis would drive base excess negative because bicarbonate is consumed to neutralize the excess acid. Primary respiratory disorders alter CO2; any changes in base excess there come from the body's metabolic compensation, not from the primary abnormality. So a positive base excess most closely points to a metabolic alkalosis.