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

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 2/3^rd 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 (pus.in 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.