Pleural effusion

Q1: What is pleural effusion?

• Normal pleural space is lined by a thin film of fluid. Visceral and parietal pleura are in opposition and glide over  each other during respiration.
• When excess fluid accumulates in pleural space it is called pleural effusion.

Q2: What are the types of fluid that can accumulate in pleural space?

Transudate  Exudate Pus Blood  Chyle Cholesterol Urine

Q3: What are the mechanisms by which fluid accumulates in pleural space?

• Transudate: Due to hydrostatic pressure changes as in CHF, cirrhosis and hypoalbuminemia
• Exudate:     Due to inflammation of pleura as in malignancy, rheumatoid arthritis, etc.
• Pus:           Empyema from infections
• Blood:        Trauma
• Chyle:        From rupture of thoracic duct
• Urine:         Urinothorax in hydronephrosis