Pleural Effusion
Pleural Effusion was found in 5-Minute Clinical Consult which helps you diagnose, treat, and follow up on over 900 medical conditions seen in everyday practice.

To view this entire topic, please or purchase a subscription.

Explore 5-Minute Clinical Consult - view these FREE monographs:

5-Minute Clinical Consult

-- The first section of this topic is shown below --

Basics

Abnormal accumulation of fluid in the pleural space

Description

Types:

  • Congestive heart failure (CHF) (40%)
  • Pneumonia (25%), malignancy (15%), and pulmonary embolism (PE) (10%) account for exudative effusions.
  • Malignant: Lung cancer and metastases of breast, ovary, and lymphoma

Epidemiology

Incidence
Estimated 1.3 million cases/year in the US; CHF: 500,000; pneumonia, 300,000; malignancy, 200,000; PE, 150,000; cirrhosis, 150,000; tuberculosis (TB), 2,500; pancreatitis, 20,000; collagen-vascular disease, 6,000.

Prevalence
  • Estimated 320 cases/100,000 people in industrialized countries. In hospitalized patients with AIDS prevalence is 7–27%
  • No gender predilection: ~2/3 of malignant pleural effusions occur in women.

Risk Factors

  • Occupational exposures and drugs
  • PE; TB; bacterial pneumonias (40%)
  • Opportunistic infections (in HIV patients when CD4 count is <150 cells/μL)

Pathophysiology

  • Pleural fluid formation exceeds pleural fluid absorption.
  • Transudates result from imbalances in hydrostatic and oncotic forces:
    • Increase in hydrostatic and/or low oncotic pressures; increase in pleural capillary permeability; lymphatic obstruction or impaired drainage; movement of fluid from the peritoneal or retroperitoneal space

Etiology

  • Transudates:
    • CHF: 40% of transudative effusions; 80% bilateral. Constrictive pericarditis, atelectasis; superior vena cava syndrome
    • Cirrhosis (hepatic hydrothorax): 2/3 right side; nephrotic syndrome, hypoalbuminemia; mixedema
    • Urinothorax, central line misplacement; peritoneal dialysis
  • Exudates:
    • Lung parenchyma infection, bacterial (parapneumonic, tuberculous pleurisy) fungal, viral, parasitic (amebiasis, Echinococcus)
    • Malignancy: Lung cancer, metastases (breast, lymphoma, ovaries), mesothelioma
    • Pulmonary embolism (25% of PEs are transudate)
    • Collagen-vascular disease: Rheumatoid arthritis, systemic lupus erythematosus (SLE), Wegener granulomatosis, sarcoidosis
    • GI: Pancreatitis, esophageal rupture, abdominal abscess, after liver transplant. Chylothorax: Thoracic duct tear, malignancy
    • Hemothorax: Trauma, PE, malignancy, coagulopathy, aortic aneurysm
    • Others: After coronary artery bypass graft (CABG); Dressler syndrome; uremia, asbestos exposure, radiation; drug-induced: Nitrofurantoin, bromocriptine, amiodarone, procarbazine, methysergide, hydralazine, procainamide, quinidine, methotrexate, and methysergide; Meigs syndrome; yellow-nail syndrome; ovarian stimulation syndrome; lymphangiomatosis; acute respiratory distress syndrome (ARDS)
    • Chylothorax: Thoracic duct tear, malignancy

Commonly Associated Conditions

Hypoproteinemia, heart failure, cirrhosis

-- To view the remaining sections of this topic, please or purchase a subscription --