Respiratory

Question 1

What are the two types of pleural effusion and their mechanisms?

Answer 1

Exudates: arise due to increased capillary permeability
Transudates: arise due to increase hydrostatic pressure or reduced oncotic pressure

Question 2

Give examples of causes of exudative pleural effusions

Answer 2

• infection
• malignancy (most common cause in over 60s)
• PE
• autoimmune disorders e.g. RA, SLE
• pancreatitis
• drugs
• post CABG

Question 3

Give examples of causes of transudative pleural effusions

Answer 3

• cardiac failure (most common cause overall, usually bilateral)
• cirrhotic liver disease
• peritoneal dialysis
• nephrotic syndrome
• hypothyroidism

Question 4

How should a suspected pleural effusion be investigated?

Answer 4

• PA CXR
• USS
• diagnostic tap for MC&S, cytology, protein, LDH, and pH

Question 5

What is Boerhaave’s syndrome?

Answer 5

• pleural effusion due to oesophageal rupture
• life threatening
• usually occurs after gastroscopy
• smaller percentage occur after to vigorous vomiting

Question 6

How can you tell between an exudative and transudative pleural effusion?

Answer 6

broadly:
exudate if protein level of >30 g/L
transudates if protein level of <30 g/L

*for borderline cases (25-35 g/L) Light’s criteria should be applied

Question 7

What are Light’s criteria?

Answer 7

An exudate is likely if at least one 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 more than two-thirds the upper limits of normal serum LDH

Question 8

What can heavily blood stained fluid sampled from a pleural effusion indicate?

Answer 8

• mesothelioma
• TB
• PE

Question 9

If fluid sampled from a pleural effusion contains high amylase levels, what underlying causes may be indicated?

Answer 9

• pancreatitis

- oesophageal perforation

Question 10

If fluid sampled from a pleural effusion is turbid or purulent, what underlying cause is indicated and how should the effusion be managed?

Answer 10

• infection

- chest drain

Question 11

If clear fluid is sampled from a suspected pleural effusion, what pH level would prompt you to insert a chest drain?

Answer 11

<7.2

Question 12

How can recurrent pleural effusions be managed?

Answer 12

• recurrent drainage
• pleurodesis
• indwelling pleural catheter
• symptom control by drug therapy e.g. steroids for dyspnoea