Pleural Effusion

Question 1

What is a pleural effusion and what are the gross classifications?

Answer 1

Collection of fluid in the pleural cavity

Classifications based on the protein content of the fluid
-transudate= <25g/L i.e. fluid TRANSfers across the vessel was

-exudate= >35g/L i.e. proteins EXscapes from the tissues

Question 2

What are the transudative causes of pleural effusion? What are the features of the pleural fluid?

Answer 2

Fluid moves across/transfers into the pleural space due to increased hydrostatic pressure OR decreased colloid osmotic pressure

Causes of shift:

• congestive heart failure
• hypoalbuminaemia
• hypothyroidism
• Meig’s syndrome

Pleural fluid:

• clear
• low protein count

Question 3

What is Meig’s syndrome?

Answer 3

Triad of:

• right sided pleural effusion (believed to be because of translocated ascites via diaphragmatic pores)
• benign ovarian tumour
• ascites

Question 4

What are exudative causes of pleural effusion? What are the features of the pleural fluid?

Answer 4

Protein escaping from tissue due to inflammatory processes:

• lung cancer
• pneumonia
• PE
• RA
• Tuberculosis

Pleural fluid:

• cloudy
• high protein content

Question 5

What might someone with pleural effusion present with and what would be found with on examination?

Answer 5

SOB
Pleuritic chest pain
Cough

Dullness over effusion
Reduced breath sounds
Asymmetrical chest expansion
Tracheal deviation or mediastinal shift if effusion large
NOTE: examination finding only tend to be present in pleural effusions >300ml

Question 6

What would you expect to find on an X-ray of someone with pleural effusion?

Answer 6

Blunting of costophrenic angles
Fluid in lung fissures
Meniscus sign
Tracheal or mediastinal deviation

Question 7

What are the stages of managing a pleural effusion?

Answer 7

Small effusions can be left to watch and wait= can resolve with treatment of underlying condition

Aspiration (thoracentesis)

• can be used to take sample or slowly aspirate the fluid away (biochem/microbio/cytology)
• 30-50ml under US guidance

Chest drain
-when indicated to drain the effusion and prevent recurrence

Question 8

When does empyema occur and why can it be more problematic to management than other forms of pleural effusion? What are the additional steps to managment?

Answer 8

Infection pleural effusion which is really proteinatious= very prone to clotting + pus formation

-leads to inserted chest drain becoming clogged

Steps:

• can flush with saline to loosen the clotted effusion
• can inject fibrolytic agent to loosen
• can remove in surgery

Question 9

What are the normal components of the pleural fluid?

Answer 9

WCC <1000
Glucose/Na+/K+/Ca2+ EQUAL to serum levels 
pH 7.6 
Protein <2g
LDH <0.5 time of serum

Question 10

What additional imaging can be done if empyema is suspected?

Answer 10

USS

Can show loculated effusion= evidence of pus in pleural space

Question 11

How can protein content of pleural fluid aspirate be used to inform what kind of effusion is present?

Answer 11

<25= Transudative

> 35= Exudative

25-35= Need to use lights criteria

Question 12

What is LIGHTS criteria?

Answer 12

Used to classify effusion as exudative if one (+) of following present:

• pleural fluid protein/serum protein >0.5
• pleural fluid LDH/serum LDH >0.6
• pleural fluid LDH >2/3 the upper limit of normal serum LDH level

Question 13

What results would you expect to see for a para-pneumonic effusion?
How is this form of effusion managed?

Answer 13

Ph< 7.2
No malignant cells 
High neutrophil count 
Negative MCS and TB i.e. fluid is sterile due to the infection remaining in lung parenchyma 
Raised infection markers 

Prolonged course of antibiotics (4-6 weeks)
Therapeutic drainage if large effusion and patient symptomatic

Question 14

What results would you expect to see for an effusion caused by empyema?
How is this form of effusion managed??

Answer 14

Ph< 7.2 
No malignant cells 
High neutrophil count 
MCS might grow causative agent= due to pleural fluid being infected 
Raised infection markers 

Prolonged course of Abx (6-8 weeks)
Urgent chest drain
Surgical referral if not responding to chest drain and Abx

Question 15

What results would you expect to see for tuberculous effusion?
How is this form of effusion managed?

Answer 15

Cytology shows high lymphocyte count
TB growth in 30%
ESR raised

CT thorax if pleural effusion investigations inconclusive

Management:

• RIPE
• therapeutic drainage if symptomatic and large

Question 16

What results would you expect to see for a malignant effusion? What can be done if pleural fluid analysis is inconclusive?
How is this form of effusion managed?

Answer 16

Malignant cells
CT TAP
Pleural biopsy if CT inconclusive

Management:
Treat underlying malginancy
Therapeutic aspiration/ chest drain insertion

Question 17

What are the management options for recurrent malignant pleural effusions?

Answer 17

Pleurodesis:

• chest drain inserted and fluid drained over 24-48 hrs
• lung re-expanded + Talc injected into pleural space
• talc causes inflammatory reaction between parietal and visceral pleura to adhere them together to prevent further effusions

Intrapleural catheter

• perminant indwelling catheter
• used when pleurodiesis fails (lung doesn’t re-expand)