Pleural Effusions

DefinitionIncreased amount of fluid within the pleural

cavityStedman’s Medical Dictionary

Accumulation of fluid between the layers of the membrane that lines the lungs and the chest cavityMedline Plus

EpidemiologyUnited States

1 million cases annually

Internationally320/100,000 in industrialized countries

PathophysiologyNormal: 1 mL of pleural fluid

Balance between hydrostatic/oncotic forces and lymphatic drainage

Abnormal: Pleural effusionDisruption of balance

Clinical HistoryDyspneaChest pain

Physical ExamDecreased breath soundsDullness to percussionDecreased tactile fremitusEgophonyPleural friction rub

TypesHydrothoraxHemothoraxChylothoraxPyothorax or Empyema

ClassificationTransudate

Ultrafiltrate of plasmaSmall group of etiologies

ExudateProduced by host of inflammatory conditionsLarge group of etiologies

Workup: ThoracentesisLight’s criteria: Transudate vs. Exudate

Pleural fluid protein / serum protein > 0.5Pleural fluid LDH / serum LDH > 0.6Pleural fluid LDH > 2/3 ULN serum LDH

Workup: ThoracentesisOther criteria: Transudate vs. Exudate

Pleural fluid LDH > 0.45 ULN serum LDHPleural fluid cholesterol > 45 mg/dLPleural fluid protein > 2.9 g/dL

Workup: LaboratoryLDH > 1000 IU/L

Empyema, Malignancy, Rheumatoid

Glucose < 30 mg/dLEmpyema, Rheumatoid

Glucose between 30 – 50 mg/dLLupus, Malignancy, TB

Workup: LaboratoryLymphocytes > 85%

Chylothorax, Lymphoma, Rheumatoid, TBLymphocytes between 50 – 70%

MalignancyMesothelial cells > 5%

TB unlikelyADA > 43 U/mL

Supports TB

Workup: ImagingUpright Chest X-Ray

Blunting of costophrenic angles

Supine Chest X-RayIncreased density over lower lung fields

Lateral decubitus Chest X-RayLayering

Workup: Imaging

Workup: Imaging

Workup: ImagingUltrasound

Aids in identification of loculated effusionsAids in differentiation of fluid from fibrosisAids in identification of thoracentesis siteAvailable at bedside

Workup: ImagingCT Scan

Aids in differentiation ofLung consolidation vs. Pleural effusionCystic vs. Solid lesionsPeripheral lung abscess vs. Loculated emypema

Aids in identification ofNecrotic areasPleural thickening, nodules, massesExtent of tumor

Work up: Imaging

TreatmentTreat underlying etiologyTherapeutic thoracentesis