A Simple Guide to Pleural effusion

A Simple Guide to Pleural effusion
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What is Pleural effusion?
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Pleural effusion is excess fluid collection in the pleural space between the parietal and visceral layers of the pleural cavity.

Excessive fluid can limit the expansion of the lungs and cause breathing difficulty.

What the types of Pleural effusions and their causes?
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There are 4 types of pleural effusion which can occur in the pleural space:

1.Serous fluid (hydrothorax)

This is essentially passive collection of extracellular fluid with a specific gravity of <1.015 and protein < 2-3g/dl.

It is translucent in color.

It occur as part of :
a.generalized edema

b.left heart failure

c.liver cirrhosis giving rise to hydrothorax

2.Pus (pyothorax or empyema)

This consists of inflammatory or neoplastic fluid with high protein content.

It is usually yellow or orange in color.

There may be cells or pus or bacteria.

Causes include:
a.bacterial and viral infections such as pneumonia

b.tuberculosis

c.intra-abdominal abscess

d.autoimmune diseases like SLE, rheumatoid arthritis

e.neoplasm(cancer of the lung)

3.Blood (hemothorax)

The exudate is typically blood stained.

Causes are:
a.pulmonary embolism and infarction

b.neoplasm especially with secondaries to lungs

4.Chyle (chylothorax)

Here the exudate arise from the leakage of thoracic duct.

It is milky in appearance.

Causes are:
a.Trauma including chest and heart surgery

b.filariasis in the tropics

What are the symptoms and signs of Pleural effusion?
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Symptoms:
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1.Breathless

2.Side Chest pain

3.dry cough

Signs:
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1.Dullness to percussion

2.Faint or absent breath sounds

3.Decreased movement of the chest

4.Decreased vocal resonance

5.Fremitus

6.pleural friction rub

How do you made a Diagnosis of Pleural effusion?
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Pleural effusion is usually diagnosed on:
1.medical history and physical exam,

2.chest x-ray.
Chest films with the patient lying on their side are more accurate and can show fluid level as low as 50 ml of fluid.

Upright chest films can show fluid level of at least 300ml of pleural effusion

In large effusion there may be tracheal deviation away from the effusion.

3.CT scan of chest showing left sided pleural effusion.

Effusion fluid often settles at the lowest space due to gravity;

4.Pleural tap or thoracentesis.

A needle is inserted through the back of the chest wall in sixth, seventh or eight intercostal space in midaxillary line, into the pleural space.
The fluid may then be evaluated for the following:

Chemical composition including
protein,
lactate dehydrogenase (LDH),
albumin,
amylase,
pH and
glucose

Gram stain and culture to identify possible bacterial infections

Cell count and differential white cell count

Cytology to identify cancer cells

Cytology to identify some infective organisms

Other tests :
lipids,
fungal culture,
viral culture,
specific immunoglobulins

5.Thoracoscopy
If cytology does not show cancer but cancer is still suspected, then a thoracoscopy, or needle biopsy of the pleura may be done to exclude cancer.

What is the Treatment of Pleural Effusion?
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1.Pleural Aspiration is done for relief of chest discomfortand breathlessness.

The Chest Drainage Device is usually connected to an underwater seal below the level of the chest.

Air or pleural fluid is allowed to escape from the pleural space but nothing is allowed to return to the pleural cavity.

Larger effusions may need insertion of an intercostal drain .

2.Treatment depends on the underlying cause of the pleural effusion.

a.Therapeutic aspiration may be sufficient in some cases of trauma and leakage.

b.Installation of antibiotics( eg.bleomycin, tetracycline/doxycycline) in pleural cavity

c.Installation of chemotherapy drugs for cancer into the pleural cavity.

d.treatment of filariasis cases with anti-parasitic drugs

e.surgical pleurodesis- here the parietal and visceral pleural surfaces are made to adhere to each other to prevent accumulation of fluid.

What is the Prognosis of Pleural Effusion?
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Recovery of patient from the pleural effusion after appropriate treatment of the underlying disease is the rule.

Recurrence from returning cancer or infections may be common.