Pleural effusion resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Twinkle Singh, M.B.B.S. [2]

Definition

Pleural effusion is defined as the presence of excessive fluid in the pleural cavity resulting from transudation or exudation from the pleural surfaces.

Light's Criteria

Pleural fluid is classified as an exudate if one or more of the following criteria are met.

Pleural fluid protein divided by serum protein	> 0.5
Pleural fluid LDH divided by serum LDH	> 0.6
Pleural fluid LDH > 2/3 of upper limit of normal serum LDH

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

• Pulmonary embolism
• Congestive heart failure

Common Causes

Transudate

• Left ventricular failure
• Cirrhosis
• Pulmonary embolism
• Hypoalbuminemia

Exudate

• Bacterial pneumonia
• Pulmonary embolism
• Malignancy
• Autoimmune diseases
• Pleuritis

Initial Diagnosis

Characterize the symptoms ❑ Shortness of breath ❑ Chest pain ❑ Cough

Physical examination ❑ Asymmetrical chest expansion ❑ Dullness to percussion ❑ Decreased tactile fremitus ❑ Mediastinal shift] ❑ Shift away from the effusion side in massive effusion ❑ Shift towards the effusion side in lobar bronchial obstruction ❑ Decreased breath sounds

Signs suggestive of specific etiology

Congestive heart failure ❑ Distended neck veins ❑ S3 heart sound ❑ Peripheral edema

Pulmonary embolism ❑ Thrombophlebitis ❑ Right ventricular heave ❑ Hyperventilation

Hepatic cause ❑ Signs of liver failure ❑ Ascites

Malignancy ❑ Lymphadenopathy ❑ Weight loss ❑ Hepatosplenomegaly

❑ Chest radiograph

Chest radiograph equivocal?

❑ Chest ultrasonography OR ❑ Lateral decubitus chest radiograph OR ❑ CT chest

Approach to Thoracocentesis

Assess the clinical significance of pleural effusion

Shortness of breath at rest

❑ Rule out pulmonary embolism ❑ Therapeutic thoracocentesis

> 10 mm thickness of effusion on USG

No known cause

Proceed with thoracocentesis

CHF suspected?

❑ Bilateral effusion ❑ Afebrile ❑ No chest pain

❑ Unilateral effusion

❑ Trial of diuretics

❑ Proceed with Thoracocentesis

Approach to Pleural Fluid Analysis

Pleural fluid analysis ❑ Protien ❑ LDH ❑ Gram stain ❑ Cytology ❑ Culture ❑ Pleural fluid pH (if infection is suspected)

Apply Light's criteria ❑ Measure both serum and pleural fluid protein and LDH

Transudate?

Exudate?

Treat the cause

Diagnosis found?

No

Yes

Treat the cause

Contrast enhanced CT

Cause found?

Yes

Treat the cause

No

❑ Imaging guided pleural biopsy ❑ Thoracoscopy

Cause found?

Yes

Treat the cause

No

❑ Bronchoscopy (if bronchial obstruction is suspected clinically) ❑ Mycobacterial culture ❑ Adenosine deaminase (to rule out tuberculosis) ❑ If chylothorax is suspected clinically ❑ Measure pleural fluid cholesterol crystals ❑ Chylomicrons ❑ Triglycerides ❑ Cholesterol levels

Cause found?

Yes

Treat the cause

No

Diagnose as non specific pleuritis

Reconsider following causes ❑ Tuberculosis ❑ Pulmonary embolism ❑ Lymphoma ❑ Heart failure

Waitful watch if no cause found