Pleural Effusion pleural fluid Causes Symptoms Diagnosis Treatment

  • The pleural space lies between the lung and the chest wall between the 2 layers of pleura, the visceral and parietal pleura.
  • Normally there is a thin layer of fluid in the pleural space.
  • Pleural effusion is said to be present when there- is excessive quantity of fluid in the pleural space.
  • Pleural fluid accumulates when the pleural fluid for­mation exceeds the absorption.
  • Pleural fluid may be transudate or exudate.
  • Determining the cause of a pleural effusion is greatly facilitated by analysis of the pleural fluid.
  • Fluid in the thoracic cavity between the visceral and parietal pleura. It may be seen on a chest radiograph if it exceeds 300 ml.

Physical Exam for Pleural Effusion

  • When pleural effusion >300 mL:
  • No voice transmission
  • Mediastinal shift: Usually >1,000 mL
  • Decreased or inaudible breath sounds
  • Tachypnea
  • Egophony, pleural friction rub
  • Asymmetric expansion of thoracic cage
  • Dullness to percussion
  • Decreased or absent tactile fremitus
Pleural Effusion 1

Pleural Effusion pleural fluid Causes Symptoms Diagnosis Treatment

Etiology of Pleural Effusion

Transudative effusion

  • Cirrhosis (hepatic hydrothorax): 2/3 right side
  • Nephrotic syndrome, hypoalbuminemia
  • Transudates are largely due to imbalances in hydrostatic and oncotic pressures in the chest.
  • is seen in left ventricular fail­ure, pulmonary embolism, cirrhosis.
  • CHF: 80% bilateral
  • Constrictive pericarditis
  • Urinothorax, central line misplacement
  • Atelectasis
  • Peritoneal dialysis
  • Trapped lung, peritoneal dialysis
  • Myxedema, superior vena cava obstruction

Exudative pleural effusion

  •  is found in bacterial pneumonia. mali nanc viral infection, pulmonary embolism.
  • In exudative pleural effusion
    • The ratio of pleural fluid protein / serum protein is more than 0.5.
    • The ratio of pleural fluid LDH / serum LDH is more than 0.6.
    • The pleural fluid LDH is more than 2/3rd of serum LDH.
  • GI: Pancreatitis, esophageal rupture, abdominal abscess, after liver transplant
  • Chylothorax: Thoracic duct tear, malignancy
  • With these criteria, 25% of transudates may be mis­diagnosed as exudates. So, if the clinical diagnosis is-. transudative nature of the fluid, the difference be­tween albumin levels in the seum and the pleural fluid is measured. If this difference is more than 1.2g/dl, then the fluid is a transudate.
  • Lung parenchyma infection, bacterial: parapneumonic, tuberculous pleurisy, fungal, viral
  • Disease in virtually any organ can cause exudative pleural effusions by a variety of mechanisms, including infection, malignancy, immunologic responses,
  • Parasitic (amebiasis, Echinococcus)
  • Malignancy: Lung cancer, metastases (breast, lymphoma, ovaries), mesothelioma
  • PE
  • Collagen-vascular disease: Rheumatoid arthritis, systemic lupus erythematosus (SLE), Wegener granulomatosis, sarcoidosis
  • Hemothorax: Trauma, PE, malignancy, coagulopathy, aortic aneurysm

Pleural Effusion Pathophysiology

  • The normal pleural space contains ~1 mL of fluid.
  • Trasudates result from imbalances in hydrostatic and oncotic forces.
  • Increase hydrostatic and/or low oncotic pressures
  • Increase in pleural capillary permeability
  • Pleural fluid accumulates when pleural fluid formation exceeds pleural fluid absorption.
  • Lymphatic obstruction or impaired drainage
  • Movement of fluid from the peritoneal or retroperitoneal space
  • Iatrogenic causes
  • decortication pleural effusion

Two-test rule of Pleural Effusion

  •       –  Pleural fluid cholesterol greater than 45 mg/dL – Pleural fluid LDH greater than 0.45 times the upper limit of the laboratory’s normal serum LDH Three-test rule
  •       –  Pleural fluid protein greater than 2.9 g/dL –  Pleural fluid cholesterol greater than 45 mg/dL – Pleural fluid LDH greater than 0.45 times the upper limit of the laboratory’s normal serum LDH

The pleural fluid is examined for:

  • Colour and thickness of fluid.
  • Glucose
  • Cell count and type
  • Microbiology
  •  Cytology.
  • Amylase in pleural fluid is elevated in esophageal rupture, pancreatic disease and malignancy.
  • Glucose is less than 60 mg/dl in malignancy, bacte­rial infections, rheumatoid disease.

Causes of pleural effusion Transudative

  • CHF
  • Cirrhosis
  • Nephrotic syndrome
  • Myxodema
  • Superior vena cava obstruction
  • Pulmonary embolism.

Causes of pleural effusion Exudative

  • Infections – Tuberculosis, bacterial, fungal, vi­ral, parasitic
  • Neoplastic diseases
  • Mesothelioma (primary tumor of pleura) Pulmonary embolism
  • Collagen vascular diseases .
  • Intraabdominal abscess Esophageal perforation Pancreatic disease Sarcoidosis
  • Uraemia
  • Asbestosis
  • Radiation
  • Pericardial diseases Chylothorax
  • Nitrofurantoin and amiodarone induced.

Effusion due to heart failure

  • · Pleural effusion can occur in LVF
  • · Treated with diuretics.

Hepatic causes

  • In cirrhosis and ascites usually right-sided pleu­ral effusion may occur.
  • Treatment is liver transplant or transjugular intrahepatic portal systemic shunt (TIPS).

Para pneumonic effusion

  • In bacterial pneumonia, lung abscess, bronchiecta­sis, exudative pleural effusion, or even purulent effu­sion ( the pleural cavity), called empyemais seen.
  • Treatment is thoracentesis.
  • More invasive methods of removal of fluid or pus is required ifthere is loculated effusion, or gross pus in pleural space.
  • Tube thoracostomy is done for recurrent effusions and where the prognosis is poor.

Tubercular pleuritis

  • Tuberculosis is the most common cause of pleural effusion in the developing countries. It is due to hy­persensitivity reaction to tuberculous protein in the pleural space.
  • Symptoms are fever, weight loss, dyspnoea, pleu­ritic chest pain.
  • Pleural fluid has small Iymphocytes, adenosine deaminase in the pleural fluid is more than 45 lUlL, peR for tuberculous DNA is positive.
  • Treatment is pleural aspiration and antitubercular arugs.

Treatment of Pleural Effusion

First Line Pleural Effusion treatment

  • Treat underlying cause:
  • CHF: Diuretics (75% clearing in 48 h)
  • Parapneumonic effusion: Antibiotics
  • Steroids and nonsteroidal anti-inflammatory drugs (NSAIDs) for rheumatologic and inflammatory causes

Second Line Pleural Effusion treatment

  • Symptomatic nonmalignant pleural effusions that are refractory to primary treatment may be managed with repeated therapeutic thoracentesis or pleurodesis.


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