A nurse is reviewing the arterial blood gas values of a client who has chronic kidney disease. Which of the following sets of values should the nurse expect?

This question requires knowledge of acid-base balance and pathophysiology of chronic kidney disease. Understanding how impaired renal function leads to metabolic acidosis through decreased hydrogen ion excretion and reduced bicarbonate regeneration is essential to identify the correct values. Choice A rationale A pH of 7.55 and HCO3 of 30 indicate metabolic alkalosis. Normal pH is 7.35 to 7.45 and HCO3 is 22 to 28 mEq/L. Renal failure typically results in acid accumulation, not excess base. Choice B rationale A pH of 7.30 and PaCO2 of 50 indicate respiratory acidosis. In renal failure, the lungs typically compensate for metabolic acid by hyperventilating to lower PaCO2, which is the opposite of the hypoventilation shown here. Choice C rationale A pH of 7.50 and PaCO2 of 32 indicate respiratory alkalosis. This state occurs when the patient hyperventilates excessively, leading to an alkaline pH, which does not align with the metabolic acidosis expected in renal disease. Choice D rationale Chronic kidney disease causes metabolic acidosis. A pH of 7.25 and HCO3 of 19 mEq/L demonstrate low pH and low bicarbonate. The PaCO2 of 30 mm Hg reflects respiratory compensation for the primary metabolic acid-base imbalance.