A nurse is reviewing the laboratory results of a client who is postoperative and has a respiratory rate of 7/min. The arterial blood gas (ABG) values include: pH 7.22 PaCO2 68 mm Hg Base excess -2 PaO2 78 mm Hg Oxygen saturation 80% Bicarbonate 28 mEq/L Which of the following interpretations of the ABG values should the nurse make?