Pleural Effusion

Question 1

Pleural effusion : Definition

Answer 1

accumulation of fluid between the pleural layers.

Question 2

Pleural effusion : Physiology of the pleural cavity

Answer 2

Pleural cavity : space between the parietal pleura which is stuck onto the chest wall and visceral pleura which is stuck to the lungs

• Contains fluid for lubrication produced by the capillaries
• Lymphatic vessels : drain the pleural fluid and prevent it accumulating

Question 3

Pleural effusion : Transudative pleural effusion - definition

Answer 3

• /Increase in hydrostatic pressure/
• /Reduced oncotic pressure/

Answer 4

1. Increase in hydrostatic pressure
   * Right sided heart failure
   * Chronic pulmonary disease - PE, atelectasis, malignancy: Pulmonary vasoconstriction 2nd to inflammation and damage of lung tissue causes pulmonary hypertension
2. Reduced oncotic pressure
   * Liver cirrhosis
   * Nephrotic syndrome

Question 5

Pleural effusion : Exudative pleural effusion : Definition

Answer 5

• Inflammation of the pulmonary capillaries
• increase in capillary permeability
• Allows for pulmonary capillary content to enter the pleural space.

Question 6

Pleural effusion : Exudative pleural effusion : Causes

Answer 6

1. Infection : TB, empyema
2. Connective tissue disease : Rheumatoid arthritis, SLE
3. Malignancy, asbestosis, mesothelioma, sarcoidosis
4. Dressler’s syndrome, pancreatitis
5. Drug induced - Methotrexate, amiodorone, phenytoin

Question 7

Pleural effusion : Clinical features

Answer 7

1. SOB - worse lying down
2. Reduced chest wall movement, breath sounds, vocal resonance
3. Tacheal deviation - away from the side of the effusion

Question 8

Pleural effusion : Investigations

Answer 8

1. CXR : concave meniscus sign, blunting of costaphrenic angle
2. US / CT to r/o malignancy
3. Pleural aspiration

Question 9

Pleural effusion : Pleural aspiration - Light’s criteria

Answer 9

1. Exudates have a protein level of >30g and transudate fluid <30g/L

or

2. If Protein level is between 25-35g/L, Exudate is more likely if;
   * Pleural fluid protein divided by serum protein >0.5
   * Pleural fluid LDH divided by serum LDH >0.6
   * Pleural fluid LDH is > 2/3 upper limits of normal serum LDH.

Question 10

Pleural effusion : Indication for chest drain

Answer 10

1. Pleural fluid PH < 7.2
2. Pleural fluid turbid/cloudy ? Signs of infection
3. Large, symptomatic pleural effusion
4. Empyema

Question 11

Pleural effusion : Management

Answer 11

1. Small effusion 2nd to HF : treated with diuretics and sodium restriction
2. Pleural aspiration +/- Chest drain