Back to Topics
Pleural
Pleural Effusion: Diagnosis & Management
Added by Dr. Andrew · Last updated 2024-01-15
Overview
Pleural effusions are classified as transudates or exudates using Light's criteria. The most common causes are heart failure (transudate), malignancy, and parapneumonic effusion (exudates). Accurate diagnosis requires thoracentesis with appropriate fluid analysis.
Key Points
- 1Light's criteria (exudate if ANY): pleural/serum protein >0.5, pleural/serum LDH >0.6, pleural LDH >2/3 upper limit of normal serum LDH
- 2Common transudates: heart failure, cirrhosis, nephrotic syndrome, hypoalbuminemia
- 3Common exudates: malignancy, parapneumonic/empyema, TB, PE, rheumatoid
- 4Parapneumonic effusion: simple (antibiotics only) vs complicated (pH <7.2, glucose <60, LDH >1000, positive culture/Gram stain) → drainage
- 5Empyema: frank pus → chest tube drainage ± fibrinolytics (MIST2 trial)
- 6Malignant effusion: IPC (indwelling pleural catheter) vs pleurodesis (AMPLE trial: IPC non-inferior)
Clinical Pearls
- Serum-pleural albumin gradient >1.2 g/dL = transudate (corrects for diuretic-treated HF)
- Chylothorax: triglycerides >110 mg/dL; caused by lymphoma, trauma, thoracic duct injury
- Yellow nail syndrome: yellow nails + lymphedema + pleural effusion
- Mesothelioma: asbestos exposure + unilateral effusion + pleural thickening — diagnose by thoracoscopy
Board High-Yield
Exam Focus- Light's criteria: memorize all three — any one positive = exudate
- Complicated parapneumonic: pH <7.2 = drain (most important criterion)
- MIST2: intrapleural tPA + DNase superior to either alone for empyema
- AMPLE: IPC = pleurodesis for malignant effusion (IPC preferred for short life expectancy)
- Transudative effusion with fever/pleurisy: think PE (up to 20% of PE have effusion)
ABIM Exam Weight
5%
Pleural Disease represents approximately 5% of the PCCM certification exam.