The health care provider orders serial arterial blood gases (ABGS) for a client with chronic obstructive pulmonary disease (COPD) who is experiencing respiratory acidosis. At 0800, the client's ABG results were pH 7.28, PaCO2 66 mmHg, and HCO3 22 mEq/L. Which ABG results drawn at 1000 indicate the client's condition is declining?