Bicarbonate level less than 22 mEq/L indicates which disturbance?

Bicarbonate level less than 22 mEq/L indicates which disturbance?

• A. Metabolic acidosis
• B. Metabolic alkalosis
• C. Respiratory acidosis
• D. Respiratory alkalosis

Answer: (A)

Bicarbonate is the main base used to buffer acids in the blood. When its level falls below about 22 mEq/L, it points to metabolic acidosis—the body has an excess of acid or a loss of base, so the pH drops. In metabolic acidosis, you expect low HCO3- with a low pH, and the respiratory system will compensate by increasing ventilation to blow off CO2 (lower PaCO2). If bicarbonate were high, that would suggest metabolic alkalosis. Respiratory disorders center on CO2; they may cause compensatory changes in bicarbonate, but a low bicarbonate is best explained by a metabolic acidosis.

Bicarbonate is the main base used to buffer acids in the blood. When its level falls below about 22 mEq/L, it points to metabolic acidosis—the body has an excess of acid or a loss of base, so the pH drops. In metabolic acidosis, you expect low HCO3- with a low pH, and the respiratory system will compensate by increasing ventilation to blow off CO2 (lower PaCO2). If bicarbonate were high, that would suggest metabolic alkalosis. Respiratory disorders center on CO2; they may cause compensatory changes in bicarbonate, but a low bicarbonate is best explained by a metabolic acidosis.