Pleural Effusions

Question 1

What is a pleural effusion?

Answer 1

fluid around the lungs that collects in the pleural space between the chest wall and the lungs.

Question 2

How would a pleural effusion present on a CXR?

Answer 2

blunting of the costophrenic and cardiophrenic angles

Question 3

What are two types of pleural effusion?

Answer 3

Transudate and exudate (contains more protein)

Question 4

what are the features of pleural effusions? (symptoms and features on examination)

Answer 4

Features
Symptoms: dyspnoea, non-productive cough or chest pain
On Examination: dullness to percussion, reduced breath sounds and reduced chest expansion

Question 5

what are some causes of a transudative pleural effusion?

Answer 5

heart failure (most common transudate cause)
hypoalbuminaemia (liver disease, nephrotic syndrome, malabsorption)
hypothyroidism
Meigs’ syndrome (triad of benign ovarian tumor with ascites and pleural effusion that resolves after resection of the tumor.)

Question 6

what are some causes of a exudative pleural effusion?

Answer 6

infection: pneumonia (most common exudate cause), TB, subphrenic abscess
connective tissue disease: RA, SLE
neoplasia: lung cancer, mesothelioma, metastases
pancreatitis
pulmonary embolism
Dressler’s syndrome
yellow nail syndrome

Question 7

what 3 imaging investigations would you consider in pleural effusions?

Answer 7

Imaging

• posterioranterior (PA) chest x-rays should be performed in all patients
• ultrasound is recommended: it increases the likelihood of successful pleural aspiration and is sensitive for detecting pleural fluid septations
• contrast CT is now increasingly performed to investigate the underlying cause, particularly for exudative effusions

Question 8

when a pleural aspiration is performed in a pleural effusion what is the sample tested for?

Answer 8

fluid should be sent for pH, protein, lactate dehydrogenase (LDH), cytology and microbiology

Question 9

what size needle and syringe would you use in a pleural aspiration?

Answer 9

a 21G needle and 50ml syringe should be used

Question 10

what criteria is used to distinguish between a transudate and an exudate pleural effusion?

Answer 10

Lights criteria

NB this is used when the protein level is 25-35 so not obviously high or low

Question 11

Using lights criteria what would suggest a pleural effusion is an exudate?

Answer 11

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 12

if the pleural fluid is found to be low in glucose what are 2 possible differentials?

Answer 12

low glucose: rheumatoid arthritis, tuberculosis

Question 13

if the pleural fluid is found to have a raised amylase what are 2 possible differentials?

Answer 13

raised amylase: pancreatitis, oesophageal perforation

Question 14

if the pleural fluid is found to have heave blood staining what are 3 possible differentials?

Answer 14

heavy blood staining: mesothelioma, pulmonary embolism, tuberculosis

Question 15

True or false
All patients with a pleural effusion in association with sepsis or a pneumonic illness require diagnostic pleural fluid sampling

Answer 15

True

Question 16

Options for managing patients with recurrent pleural effusions include:

Answer 16

recurrent aspiration
pleurodesis
indwelling pleural catheter
drug management to alleviate symptoms e.g. opioids to relieve dyspnoea