A nurse is caring for a female client in the emergency department who reports shortness of breath and pain in the lung area. She states that she started taking birth control pills 3 weeks ago and that she smokes. Her heart rate is 110/min, respiratory rate 40/min, and blood pressure 140/80 mm Hg. Her arterial blood gases are pH 7.50, PaCO2 29 mm Hg, PaO2 60 mm Hg, HCO3 20 mEq/L, and SaO2 86%. Which of the following is the priority nursing intervention?