Intensive Care Medicine (ICM) Practice Exam

Which condition would most likely show fluid levels in the thoracic cavity?

1. Atypical pneumonia

2. Pneumonia

3. Pleural effusion

4. Pneumothorax

The correct answer is: Pleural effusion

Fluid levels in the thoracic cavity are most commonly observed in conditions where there is an accumulation of fluid within the pleural space. Pleural effusion specifically describes the presence of excess fluid in the pleural cavity. This fluid can result from various underlying conditions, including heart failure, infection, malignancy, or inflammation. In radiological imaging, particularly chest X-rays, pleural effusions can be characterized by a blunting of the costophrenic angles and a meniscus sign, indicating fluid presence that may create a visible level. The diagnosis is often confirmed with ultrasound or CT scans, which can further delineate the volume and nature of the effusion. In contrast, atypical pneumonia and pneumonia primarily involve the lung parenchyma rather than the pleural space, and while they may lead to complications such as empyema (infected pleural effusion), they do not inherently cause fluid levels in the thoracic cavity. A pneumothorax, characterized by air in the pleural space, would show free air instead of fluid accumulation, thus differentiating it from pleural effusion.