Intensive Care Medicine (ICM) Practice Exam

Which of the following conditions can lead to exudative pleural effusion?

1. Congestive heart failure

2. Liver cirrhosis

3. Pneumonia

4. Nephrotic syndrome

The correct answer is: Pneumonia

Exudative pleural effusions occur when the pleural fluid is formed due to increased production or decreased absorption of fluid associated with inflammation, infection, or malignancy. In the case of pneumonia, the inflammatory response leads to an increase in vascular permeability and subsequent accumulation of protein-rich fluid in the pleural space. This is often due to the presence of infectious agents, which can provoke a strong immune response and alter vascular dynamics, allowing for the migration of proteins and cells into the pleural cavity, thus categorizing it as exudative. In contrast, conditions like congestive heart failure and liver cirrhosis typically lead to transudative effusions. These are characterized by fluid that is low in protein and occurs due to systemic factors like hydrostatic or oncotic pressure changes rather than inflammation. Nephrotic syndrome, similar to the other mentioned transudative causes, is associated with significant protein loss in urine, leading to a low serum albumin and shifts in oncotic pressure, resulting in transudative fluid accumulation. Therefore, pneumonia is a clear example of a condition that can lead to exudative pleural effusion due to its underlying inflammatory processes.