A nurse is caring for a client who is 1 day postoperative following an open thoracotomy. The client is receiving oxygen mist at 40% by face tent. The client's SPO2 is 89-96%. ABG results are: pH 7.31, PaO2 93 mm Hg, PCO2 50 mm Hg, HCO3 25 mEq/L. Which of the following is an appropriate action by the nurse?

B Place the client in high-Fowler's position and encourage the use of incentive spirometer and coughing. D Switch oxygen to a nonrebreather mask. C Increase oxygen to 70%. A Position the client prone and have the respiratory therapist perform postural drainage.