Transudates occur when systemic factors that control formation and absorption of pleural fluid are altered.

Transudates occur when systemic factors that control formation and absorption of pleural fluid are altered.

• A. Local factors
• B. Systemic factors
• C. Lymphatic drainage factors
• D. Infectious factors

Answer: (B)

Transudative pleural effusions arise from systemic imbalances that shift the formation and removal of pleural fluid, rather than from local pleural inflammation. The pleural space is normally in balance, with fluid formed by capillary filtration and removed by lymphatics and reabsorptive forces. When systemic conditions raise hydrostatic pressure (for example, congestive heart failure) or lower oncotic pressure (such as hypoalbuminemia from cirrhosis or nephrotic syndrome), more fluid is pushed into the pleural space and is not accompanied by inflammation. The fluid tends to be low in protein and LDH because it’s essentially a filtered plasma fluid. In contrast, processes that involve local inflammation or infection increase vascular permeability, producing exudates that are richer in protein and cells. Lymphatic drainage problems can cause effusions too, but they’re not the classic transudative pattern.

Transudative pleural effusions arise from systemic imbalances that shift the formation and removal of pleural fluid, rather than from local pleural inflammation. The pleural space is normally in balance, with fluid formed by capillary filtration and removed by lymphatics and reabsorptive forces. When systemic conditions raise hydrostatic pressure (for example, congestive heart failure) or lower oncotic pressure (such as hypoalbuminemia from cirrhosis or nephrotic syndrome), more fluid is pushed into the pleural space and is not accompanied by inflammation. The fluid tends to be low in protein and LDH because it’s essentially a filtered plasma fluid. In contrast, processes that involve local inflammation or infection increase vascular permeability, producing exudates that are richer in protein and cells. Lymphatic drainage problems can cause effusions too, but they’re not the classic transudative pattern.