A patient diagnosed with emphysema is experiencing increased shortness of breath and hypoxemia. What nursing intervention would most effectively address impaired gas exchange?

A. Encouraging deep breathing exercises: While deep breathing is generally helpful, it may be difficult for a patient with emphysema who suffers from air trapping. Without proper positioning, these exercises may not be enough to overcome the mechanical disadvantage of a flattened diaphragm. It is a secondary supportive measure for pulmonary hygiene. B. Restricting fluid intake: Fluid restriction is not indicated for emphysema unless the patient has developed secondary right-sided heart failure. In fact, adequate hydration is usually encouraged to keep secretions thin and easy to expectorate. Restricting fluids without a specific cause could lead to thickened mucus and worsening obstruction. C. Positioning the patient in high Fowler's: Elevating the head of the bed to 60 to 90 degrees allows for maximum diaphragmatic excursion and chest expansion. This position uses gravity to pull the abdominal contents downward, reducing pressure on the lungs and improving the efficiency of gas exchange. It is the most effective immediate non-pharmacological intervention. D. Administering bronchodilators: These medications help open the airways but may not be enough to resolve acute hypoxemia if the patient's positioning is poor. While they are a vital part of the pharmacological regimen, they work best when combined with optimal positioning. Positioning provides an immediate mechanical advantage for ventilation.