Pleural effusion

Question 1

What is pleural effusion?

Answer 1

Fluid collecting between parietal + visceral pleura

Question 2

What are the 2 types of fluid pleural effusions can be classified upon?

Answer 2

Transudate: <30g/L protein

Exudate: >30g/L protein

Question 3

What mechanism causes an exudate?

Answer 3

Inflammation causes increased permeability of pleural capillaries- leaking intravascular fluid (cells, their contents + proteins)

Question 4

What mechanism causes a transudate?

Answer 4

Hydrostatic forces cause extravasation of fluid through a normal membrane

Question 5

Give 4 causes of transudative pleural effusion

Answer 5

HF (most common)
Hypoalbuminaemia
Hypothyroidism
Meig’s syndrome

Question 6

Give 3 causes of hypoalbuminaemia

Answer 6

Liver disease
Nephrotic syndrome
Malabsorption

Question 7

Give 7 causes of exudative pleural effusion

Answer 7

Infection
Malignancy
CTDs: RhA + SLE
PE
Pancreatitis
Dressler’s syndrome
Yellow nail syndrome

Question 8

Give 3 infectious causes of pleural effusion

Answer 8

Pneumonia (most common exudative cause)
TB
Subphrenic abscess

Question 9

List 3 types of malignancy that can cause exudative pleural effusion

Answer 9

Lung cancer
Mesothelioma
Mets

Question 10

What criteria is used to determine if the fluid is an exudate?

Answer 10

Light’s criteria
Ratio of pleural fluid to serum protein >0.5
Ratio of pleural fluid to serum LDH >0.6
Pleural fluid LDH >2/3 the upper limit of normal serum value

Question 11

What is indicated by frankly purulent fluid?

Answer 11

Empyema

Question 12

What is indicated by milky fluid? What is this likely caused by?

Answer 12

Chylothorax or pseudochylothorax
Lymphatic obstruction secondary to malignancy, chronic inflammation or thoracic duct injury

Question 13

What is indicated by bloody fluid?

Answer 13

Trauma
(Less commonly TB, PE, aortic dissection, ruptured aortic aneurysm, malignancy)

Question 14

What does the presence of food particles indicate?

Answer 14

Oesophageal rupture

Question 15

What is black pleural fluid indicative of?

Answer 15

Extremely rare!
Aspergillus niger infection
Malignant melanoma
Haemorrhage + haemolytic a/w non-small cell lung cancer

Question 16

What does pleural fluid LDH level >1000 IU/L indicate?

Answer 16

Empyema
Malignancy
Rheumatoid effusion

Question 17

Give 3 symptoms of pleural effusion

Answer 17

Dyspnoea
Non-productive cough
Chest pain

Question 18

Give 3 signs of pleural effusion

Answer 18

Dullness to percussion
Reduced breath sounds
Reduced chest expansion

Question 19

What investigations should be performed in pleural effusion?

Answer 19

PA CXR
+/- US
+/- Contrast CT

Question 20

Why is US recommended in pleural effusions?

Answer 20

Increases likelihood of successful pleural aspiration + is sensitive for detecting pleural fluid septations

Question 21

Why is CT increasingly performed in pleural effusion?

Answer 21

Ix underlying cause, esp if exudative

Question 22

When should Light’s criteria be used?

Answer 22

Protein level 25-35g/L

Question 23

How should pleural aspiration be performed?

Answer 23

US guided
21G needle + 50ml syringe
Fluid sent for pH, protein, LDH, cytology + microbiology

Question 24

What does low glucose in pleural fluid indicate?

Answer 24

Empyema
RhA
TB

Question 25

What does raised amylase in pleural fluid indicate?

Answer 25

Pancreatitis
Oesophageal perforation

Question 26

What is first line management for pleural effusion caused by congestive HF?
What should be considered if symptomatic, large effusion?

Answer 26

Furosemide PO/ IV

Consider therapeutic thoracentesis

Question 27

What is first line management for pleural effusion caused by infection?

Answer 27

IV Abx: Co-amoxiclav + Metronidazole IV

Therapeutic thoracentesis if clinical deterioration/ increasing fluid

Question 28

What do all patients with a pleural effusion in a/w sepsis or pneumonic illness require?

Answer 28

Diagnostic pleural fluid sampling
Purulent or turbid/ cloudy: insert chest drain
Clear but pH <7.2: insert chest drain

Question 29

Give 4 options for managing patients with recurrent pleural effusions

Answer 29

Recurrent aspiration
Pleurodesis
Indwelling pleural catheter
Drug Mx to alleviate Sx e.g. opioids to relieve dyspnoea

Question 30

What is first line management for pleural effusion caused by malignancy in a patient with poor performance status?

Answer 30

Therapeutic thoracentesis

Question 31

What is first line management for pleural effusion caused by malignancy in a patient with good performance status?

Answer 31

Insertion of temporary chest tube + when drained, talc pleurodesis

Question 32

What is pleurodesis?

Answer 32

Procedure to obliterate the pleural space

Question 33

Name a complication of rapid drainage via chest drain insertion in pleural effusion

Answer 33

Re-expansion pulmonary oedema
due to lung interstitial damage plus hydrostatic imbalance that occur following rapid expansion of the underlying collapsed lung

Question 34

When should re-expansion pulmonary oedema be suspected?

Answer 34

Onset of cough +/- SOB

Question 35

Describe management of suspected re-expansion pulmonary oedema

Answer 35

Clamp chest drain
Urgent CXR

Question 36

How can re-expansion pulmonary oedema be avoided?

Answer 36

Drain tubing should be clamped regularly in the event of rapid fluid output
i.e. drain output should not exceed 1L of fluid over a short period of time (<6h).