The nurse is caring for a diabetic patient in renal failure. Which laboratory findings are consistent with metabolic acidosis?

Choice A reason: pH 7.35, PaCO2 40 mm Hg, HCO3- 25 mEq/L are normal values, indicating no acidosis. Metabolic acidosis involves low pH and low bicarbonate, which this does not show, making it incorrect. Choice B reason: pH 7.4 is normal, and HCO3- 35 mEq/L suggests metabolic alkalosis, not acidosis. Renal failure and diabetes typically cause acidosis due to acid accumulation, making this inconsistent with metabolic acidosis. Choice C reason: pH 7.3 (low) and HCO3- 19 mEq/L (low) with normal PaCO2 indicate metabolic acidosis, common in renal failure due to impaired acid excretion and diabetic ketoacidosis, making this the correct choice. Choice D reason: pH 7.45 and HCO3- 30 mEq/L suggest metabolic alkalosis, not acidosis. Elevated bicarbonate is opposite to the low levels expected in metabolic acidosis, making this incorrect for the patient’s condition.