A male client with Guillain-Barré syndrome develops respiratory acidosis as a result of reduced alveolar ventilation. Which combination of arterial blood gas (ABG) values confirms respiratory acidosis?

PH, 7.25; PaCO2 50 mm Hg

In respiratory acidosis, ABG analysis reveals an arterial pH below 7.35 and partial pressure of arterial carbon dioxide (PaCO2) above 45 mm Hg. Therefore, the combination of a pH value of 7.25 and a PaCO2 value of 50 mm Hg confirms respiratory acidosis. A pH value of 5.0 with a PaCO2 value of 30 mm Hg indicates respiratory alkalosis. PH, 7.40; PaCO2 35 mm Hg and pH, 7.35; PaCO2 40 mm Hg represent normal ABG values, reflecting normal gas exchange in the lungs.