Pleural Effusions Kara Lee Gallagher USC School of Medicine

Definition Increased amount of fluid within the pleural cavity Stedman’s Medical Dictionary Accumulation of fluid between the layers of the membrane that lines the lungs and the chest cavity Medline Plus

Epidemiology United States 1 million cases annually Internationally 320/100,000 in industrialized countries

Pathophysiology Normal: 1 mL of pleural fluid Balance between hydrostatic/oncotic forces and lymphatic drainage Abnormal: Pleural effusion Disruption of balance

Clinical History Dyspnea Chest pain

Physical Exam Decreased breath sounds Dullness to percussion Decreased tactile fremitus Egophony Pleural friction rub

Types Hydrothorax Hemothorax Chylothorax Pyothorax or Empyema

Classification Transudate Ultrafiltrate of plasma Small group of etiologies Exudate Produced by host of inflammatory conditions Large group of etiologies

Workup: Thoracentesis Light’s criteria: Transudate vs. Exudate Pleural fluid protein / serum protein > 0.5 Pleural fluid LDH / serum LDH > 0.6 Pleural fluid LDH > 2 / 3 ULN serum LDH

Workup: Thoracentesis Other criteria: Transudate vs. Exudate Pleural fluid LDH > 0.45 ULN serum LDH Pleural fluid cholesterol > 45 mg/dL Pleural fluid protein > 2.9 g/dL

Workup: Laboratory LDH > 1000 IU/L Empyema, Malignancy, Rheumatoid Glucose < 30 mg/dL Empyema, Rheumatoid Glucose between 30 – 50 mg/dL Lupus, Malignancy, TB

Workup: Laboratory Lymphocytes > 85% Chylothorax, Lymphoma, Rheumatoid, TB Lymphocytes between 50 – 70% Malignancy Mesothelial cells > 5% TB unlikely ADA > 43 U/mL Supports TB

Workup: Imaging Upright Chest X-Ray Blunting of costophrenic angles Supine Chest X-Ray Increased density over lower lung fields Lateral decubitus Chest X-Ray Layering

Workup: Imaging

Ultrasound Aids in identification of loculated effusions Aids in differentiation of fluid from fibrosis Aids in identification of thoracentesis site Available at bedside

Workup: Imaging CT Scan Aids in differentiation of Lung consolidation vs. Pleural effusion Cystic vs. Solid lesions Peripheral lung abscess vs. Loculated emypema Aids in identification of Necrotic areas Pleural thickening, nodules, masses Extent of tumor

Work up: Imaging

Treatment Treat underlying etiology Therapeutic thoracentesis

Questions? Image sources cited in notes