Pleural effusion

Question 1

What is it?

Answer 1

Fluid in the pleural space

Question 2

Other substances that can enter the pleural space

Answer 2

Blood -> Haemothorax
Pus -> Empyema
Chyle (lymph with fat) -> Chylothorax
Blood and air -> haemopneumothorax

Question 3

Types

Answer 3

Transudate (protein concentration <25g/L)
Exudate (protein concentration >35g/L)
Chylothorax (less common)

Question 4

What is chylothorax

Answer 4

Lymph formed in digestive system enters the pleural cavity

Question 5

Aetiology of transudate

Answer 5

Increased venous pressure (cardiac failure, constrictive pericarditis, fluid overload)
Hypoproteinaemia (cirrhosis, nephrotic syndrome, malabsorption)
Hypothyroidism (right pleural effusion and ovarian fibroma)

Question 6

Aetiology of exudate

Answer 6

Pneumonia
Malignancy
Pulmonary embolus with infarction

Question 7

Aetiology of chylothorax

Answer 7

Neoplasm
Trauma
TB
Sarcoidosis
Cirrhosis

Question 8

Pathophysiology of transudate

Answer 8

Disruption of the hydrostatic and oncotic forces operating across the pleural membranes

Question 9

Pathophysiology of exudate

Answer 9

Increased permeability of the pleural surface and/or capillaries (inflammation)

Question 10

Pathophysiology of chylothorax

Answer 10

Due to either disruption or obstruction of the thoracic duct

Question 11

Symptoms

Answer 11

Asymptomatic

or dyspnoea or pleuritic chest pain

Question 12

Signs

Answer 12

Reduced chest wall movement/expansion
Dull ‘stony’ percussion
Diminished breath sounds (on affected side)
Reduced vocal resonance

Question 13

Diagnostic tests

Answer 13

CXR
Ultrasound (good at identifying presence of pleural fluid and guiding aspiration)
Diagnostic Aspiration
Pleural biopsy

Question 14

What would imply the presence of a pneumothorax on CXR

Answer 14

completely flat horizontal upper border

Question 15

Describe process of diagnostic aspiration

Answer 15

Percuss the upper border of pleural effusion and choose a site 1 or 2 intercostal spaces below it
Infiltrate the pleura with some lidocaine
Using a needle and syringe, without some pleural fluid and send to lab for clinical chemistry, bacteriology, cytology and immunology if indicated

Question 16

What would you be assessing if sent sample to lab for clinical chemistry analysis

Answer 16

Protein
Glucose
pH
LDH
Amylase

Question 17

What would you be assessing if sent sample to lab for bacteriology analysis

Answer 17

Microscopy and culture
Auramine stain
TB culture

Question 18

What would you be assessing if sent sample to lab for immunology analysis

Answer 18

Rheumatoid factor
ANA (Antinuclear antibody for SLE)
Complement levels

Question 19

What in sample is measured in cytology

Answer 19

Neutrophils
Lymphocytes
Mesothelial cells
Abnormal mesothelial cells
Multi-nucleated giant cells
Lupus erythematosus cells (for SLE)
Malignant cells (for Malignancy)

Question 20

What would presence of abnormal mesothelial cells be indicative of in cytology analysis

Answer 20

Mesothelioma

Question 21

What would presence of multi-nucleated giant cells be indicative of in cytology analysis

Answer 21

Rheumatoid arthritis

Question 22

What would presence of high mesothelial cells be indicative of in cytology analysis

Answer 22

Pulmonary infarction

Question 23

What could presence of high neutrophils be indicative of in cytology analysis

Answer 23

Parapneumonic effusion

Pulmonary Embolism

Question 24

What could presence of high lymphocytes be indicative of in cytology analysis

Answer 24

Malignancy
TB
RA
SLE
Sarcoidosis

Question 25

In pleural fluid analysis, what gross appearance suggests a cause of transudate or exudate pleural effusion

Answer 25

Clear, straw-coloured appearance

Question 26

Describe management of pleural effusion

Answer 26

Drainage (if symptomatic)
Pleurodesis
Intra-pleural alteplase and dornase alfa (for empyema)
Surgery if persistent collections and increasing pleural thickness (seen on ultrasound)