What should the principal diagnosis be for a patient with cough and green sputum who is treated with IV antibiotics?

• A. Bronchitis
• B. Pneumonia
• C. Secondary neoplasm of the brain
• D. Lung cancer

Answer: (B)

The principal diagnosis for a patient presenting with cough and green sputum who is treated with IV antibiotics is pneumonia. This conclusion is based on the clinical symptoms and the treatment method used.

A cough accompanied by green sputum is often indicative of a respiratory infection, particularly one that results in inflammation of the lung tissue, which is characteristic of pneumonia. The presence of fever, dyspnea, and hypoxemia may accompany these symptoms if pneumonia is severe. The treatment with intravenous antibiotics further suggests a bacterial infection that warrants aggressive management due to the potential severity of pneumonia.

While bronchitis can also cause similar symptoms, it is generally managed in an outpatient setting without the need for IV antibiotics unless there are complications or exacerbations that require more intensive care. The other conditions listed, such as secondary neoplasm of the brain and lung cancer, would typically present with different symptoms and would not be primarily indicated by the acute respiratory symptoms described in this scenario. Hence, pneumonia stands out as the most clinically relevant and appropriate principal diagnosis given the context presented.