Pleural effusion

Question 1

What are the four main causes of pleural effusion?

Answer 1

heart failure, malignancy, parapneumonic, PE

Question 2

What investigations should be ordered for pleural fluid?

Answer 2

protein, LDH, pH, glucose, MCS, AFB, cytology

Question 3

According to Light’s criteria, when is an effusion exudative?

Answer 3

if any of the following 3 are present:

1. pleural protein/serum protein > 0.5
2. pleural LDH/serum LDH > 0.6
3. pleural LDH > 2/3 upper limit normal of serum level

Question 4

How many effusions are misclassified as exudates according to Light’s criteria?

Answer 4

up to 25%

Question 5

What does a serum pleural protein gradient < 31g/L mean?

Answer 5

exudate

Question 6

What does a serum pleural albumin gradient < 12g/L mean?

Answer 6

exudate

Question 7

Does connective tissue disease cause an exudate or a transudate?

Answer 7

exudate

Question 8

Name 3 drugs which cause an exudative pleural effusion

Answer 8

nitrofurantoin
amiodarone
methotrexate

Question 9

What are some common causes of a transudative pleural effusion?

Answer 9

heart failure
cirrhosis
nephrotic syndrome
peritoneal dialysis
hypoalbuminaemia

Question 10

What biomarker can assist in diagnosis of heart failure associated pleural effusion?

Answer 10

NT pro BNP

Question 11

If a neutrophilic pleural fluid has a CRP > 45 what is the most likely cause?

Answer 11

para pneumonic

Question 12

What biomarker can assist in diagnosis of tuberculosis associated pleural effusion?

Answer 12

adenosine deaminase

Question 13

How often in pleural fluid cytology positive in malignancy?

Answer 13

20-60%

Question 14

With what type of malignancy is cytology more likely to be positive?

Answer 14

adenocarcinoma

Question 15

What is the likely diagnosis if pleural fluid glucose is more than double the serum glucose?

Answer 15

peritoneal dialysis

Question 16

What is the likely diagnosis if pleural creatinine is more than double serum creatinine?

Answer 16

urinothorax

Question 17

What is the likely diagnosis if there is a raised beta2 transferrin in the pleural fluid?

Answer 17

duropleural shunt

Question 18

When might a pleural effusion that is caused by renal failure be exudative?

Answer 18

if patient is on long term haemodialysis or is uraemic

Question 19

Which patients with a pleural infection should have chest tube drainage?

Answer 19

if pleural fluid is purulent, gram stain/culture positive or pH < 7.2

Question 20

When should you consider using intrapleural t-PA or DNase in pleural infection?

Answer 20

if not responding to IV abx and chest tube drainage and VATS is not available quickly

Question 21

What did the MIST 2 trial show?

Answer 21

intrapleural t-PA-DNase therapy improved fluid drainage in patients with pleural infection and reduced frequency or surgical referral