Which statement best describes transudative pleural effusions?

Which statement best describes transudative pleural effusions?

• A. Most common cause is congestive heart failure
• B. They contain thick plasma proteins and RBCs
• C. They require chest tube drainage
• D. They are caused by infection and inflammation increasing vascular permeability

Answer: (A)

Transudative pleural effusions come from systemic factors that disturb the fluid balance across the pleural membranes, producing a clear, low-protein, low-cell fluid. The most common cause is congestive heart failure, where increased hydrostatic pressure pushes fluid into the pleural space. This type of effusion reflects a mechanical or oncotic imbalance rather than inflammation. The other statements don’t fit transudates. They typically have low protein and few cells, not thick plasma proteins and red blood cells. They usually do not require chest tube drainage unless the effusion is very large or causing symptoms. Infections and inflammation that raise vascular permeability produce exudative effusions, not transudates.

Transudative pleural effusions come from systemic factors that disturb the fluid balance across the pleural membranes, producing a clear, low-protein, low-cell fluid. The most common cause is congestive heart failure, where increased hydrostatic pressure pushes fluid into the pleural space. This type of effusion reflects a mechanical or oncotic imbalance rather than inflammation.

The other statements don’t fit transudates. They typically have low protein and few cells, not thick plasma proteins and red blood cells. They usually do not require chest tube drainage unless the effusion is very large or causing symptoms. Infections and inflammation that raise vascular permeability produce exudative effusions, not transudates.