American Board of Internal Medicine (ABIM) Certification Practice Exam

In a patient with pneumonia who exhibits clinical instability, regardless of the size of a pneumothorax, the most appropriate next step in management is to perform a needle decompression. Clinical instability indicates that the patient's condition is deteriorating, which can be due to either significant respiratory distress or cardiovascular compromise that may arise from a tension pneumothorax.

Needle decompression is a lifesaving procedure that allows for rapid release of trapped air from the pleural space, thereby alleviating pressure on the lungs and mediastinum. This can improve oxygenation and hemodynamics, providing immediate relief of symptoms.

Observation is not appropriate in the case of clinical instability, as the patient requires urgent intervention. A thoracotomy is a more invasive procedure typically reserved for other specific indications or when there are complications that cannot be managed by less invasive means. High-flow oxygen therapy can provide supportive care, but it will not address the underlying issue of an unstable pneumothorax and is not sufficient on its own in this scenario. Therefore, the intervention that addresses the immediate threat to the patient’s life is needle decompression.