Pleural Effusion

Question 1

Define pleural effusion

Answer 1

Defined as pathological collection of fluid within the pleural space

Question 2

What is the pleural space

Answer 2

Potential space between the visceral (inner layer) and parietal (outer layer) pleura

Question 3

Pleural effusion is a pathological collection of fluid within the pleural space.

What can this fluid be?

Answer 3

Blood, lymph, pus etc

Question 4

Pleural effusion can be classified into two groups according to the protein concentration.

Name these groups

Answer 4

Transudate

Exudate

Question 5

Pleural effusion can be classified into two groups according to the protein concentration: transudate and exadute.

Which one is associated with a high protein count?

Answer 5

Exudate (remember it as Exudate - Extra protein)

protein count >30g/L

Question 6

Pleural effusion can be classified into two groups according to the protein concentration: transudate and exadute.

Which one is associated with a low protein count?

Answer 6

Transudative

Protein count <30g/L

Question 7

Exudative is a classification of pleural effusion.

Define exudative pleural effusion?

Answer 7

Pleural effusion with a high protein count (>30g/L)

Remember it as Exudate = Extra protein

Question 8

Transudate is a classification of pleural effusion.

Define transudate pleural effusion?

Answer 8

Pleural effusion with lower protein count (<30g/L)

Question 9

Describe the pathogenesis of transudate pleural effusion

Answer 9

Occurs due to alteration in Starling forces i.e. hydrostatic and oncotic pressures leading to the fluid being ‘squeezed’ into the pleural space

Remember as Transudate – Transfers/moves across into the pleural space

Question 10

Describe the pathogenesis of exudate pleural effusion

Answer 10

Occurs due to a variety of inflammatory conditions that affect vessel permeability and/or lymphatic drainage and thus the fluid exits into the pleural space

Exudate – Exits/moving out of the vessels into the pleural space

Question 11

What is the most common cause of transudate pleural effusion

Answer 11

Heart failure

Question 12

Name some of the causes of transudate pleural effusion

Answer 12

Heart failure (most common transudate cause)

Hypoalbuminaemia (low serum albumin) e.g. liver disease, nephrotic syndrome, malabsorption

Hypothyroidism

Meigs’ syndrome

Question 13

What is the most common cause of exudate pleural effusion

Answer 13

Pneumonia

Question 14

Name some of the causes of exudate pleural effusion

Answer 14

Infection: pneumonia (most common exudate cause), TB, subphrenic abscess

Malignancy: commonly lung and breast

Connective tissue disease: RA, SLE

Neoplasia: lung cancer, mesothelioma, metastases

Pancreatitis

Pulmonary embolism (PE)

Question 15

Describe the percussion in the respiratory examination in a patient with a pleural effusion

Answer 15

Stony dull percussion at the bases (where the effusion is)

Question 16

What is the key clinical feature of a pleural effusion

Answer 16

Dyspnoea (SoB)

Question 17

Describe some of the signs of a pleural effusion on examination

Answer 17

Reduced chest wall movements on the affected side

Stony dull percussion note

Diminished or absent breath sounds

Decreased tactile vocal fremitus/vocal resonance

If the pleural effusion is large, the trachea may deviate away from the effusion

Question 18

If the pleural effusion is large, the trachea may deviate ___ the effusion

a) away from
b) towards

Answer 18

a) away from

Question 19

What is the first-line imaging investigation in all patients with a suspected pleural effusion

Answer 19

Chest x-ray

Question 20

What are the chest x-ray features of a pleural effusion

Answer 20

Blunting of the costophrenic angle

Fluid in the lung fissures

If large, white out or meniscus

Tracheal and mediastinal deviation away from the effusion if it is a massive effusion

Question 21

What are the two key investigations used in pleural effusion

Answer 21

Chest X-Ray - to confirm diagnosis

Diagnostic ultrasound-guided thoracentesis for pleural fluid analysis - to determine if it is transudate or exudate (required in all patients except those with clear evidence of heart failure)

Question 22

What are some of the signs suggestive of heart failure

Answer 22

Past history of ischaemic or other heart disease

Raised jugular venous pressure

Pitting oedema of the legs

ECG evidence

Raised serum brain natriuretic peptide [BNP]

Question 23

What are the features of Empyema pleural effusion (infective pleural effusion) on pleural fluid analysis

Answer 23

Presence of pus

Acidic pH (pH < 7.2)

Low glucose

High LDH

Question 24

What criteria is used to distinguish exudative and transudative pleural effusion if the protein content is equivocal (25-35 g/L)

Answer 24

Light’s criteria

Question 25

What is the use of the light criteria in pleural effusion

Answer 25

Useful to distinguish exudative and transudative if the protein content is equivocal (25-35 g/L)

Question 26

When is Conservative management appropriate as the treatment choice in pleural effusions?

Answer 26

For small effusions will resolve with treatment of the underlying cause

Question 27

Pleural effusions can be drained for symptomatic relief, but treatment should be directed towards the underlying cause.

By what two ways can a pleural effusion be drained

Answer 27

Pleural aspiration

Chest drain

Question 28

What is a potential limitation of aspirating a pleural effusion

Answer 28

Temporarily relieve the pressure but the effusion may recur and repeated aspiration may be required.

Question 29

What is the advantages of a chest drain in managing pleural effusion

Answer 29

Involves insertion of a tube into the pleural space to allow drainage over hours to days.

Drains are connected to an underwater seal to prevent backflow of air or fluid into the pleural space.

Prevents a pleural effusion from recurring

Question 30

How is Empyema pleural effusion treated?

Answer 30

Insertion of a chest drain to remove pus

Antibiotics to treat the causative infection