Pleural Effusion

Question 1

What is a pleural effusion?

Answer 1

Fluid in the pleural space

Question 2

What are the symptoms of a pleural effusion?

Answer 2

Small pleural effusions may be asymptomatic

Larger effusions cause breathlessness (dyspnoea) and pleuritic chest pain

Note- there can also be symptoms due to the cause- e.g. infective cause- fever, malaise, rigours or malignancy- weight loss, fever, fatigue

Question 3

What are the signs seen when examining a patient with a pleural effusion?

Answer 3

Decreased chest wall expansion
Decreased breath sounds on auscultation
Stony dull on percussion
Decreased vocal resonance (note this increases in a collapsed lobe)

Question 4

What is the first investigation that should be requested if suspecting a pleural effusion?

Answer 4

CXR

Question 5

What would be seen on a CXR of a pleural effusion?

Answer 5

Blunting of the costo-phrenic angles
Wide spread opacity
Meniscus
Tracheal deviation away from the effusion (due to pulling force)

Question 6

What two other imaging modalities may be requested for a patient presenting with a pleural effusion?

Answer 6

USS- Always aspirate under USS guidance

CT- If suspecting malignancy or underlying cause not known

Question 7

How much fluid should be aspirated from a pleural effusion? What is there is obvious pus when aspirating?

Answer 7

Depends on wether the patient is symptomatic or not

Asymptomatic- aspirate enough for diagnostic testing, around 20-50mls

Symptomatic- aspirate enough to reduce symptoms but do not completely drain as some more may be required later on

Note- If there is pus on aspiration then an ICD should be inserted urgently

Question 8

Describe the process by which an aspiration is taken?

Answer 8

This should be done under USS guidance
Percuss upper boundary of effusion and go 1-2 ribs beneath this
Infiltrate the area with LA
Use 21g needle to aspirate some fluid

Question 9

What tests may be requested on a pleural effusion aspirate?

Answer 9

Biochemistry- Glucose, LDH, Protein, pH, Amylase
Cytology- WCC, If suspecting malignant cells, neutrophils
Bacteriology- MC&S, ZN Stain/AFB Staining, TB Culture (if suspected)
Immunology- ANA, Anti-CCP, RF, Complement

Question 10

What can blood in pleural fluid be a sign of?

Answer 10

Malignancy
Pulmonary Infarction
Benign asbestos pleural effusion

Question 11

What can milky pleural fluid be a sign of?

Answer 11

Chylothroax- leakage from the thoracic duct

Question 12

What colour are transudates typically?

Answer 12

Straw coloured

Question 13

What might yellow-green pleural fluid be a sign of?

Answer 13

RA related effusion

Question 14

What is a transudate and what level must the protein be below to be considered a transudate?

Answer 14

Transudates are caused by factors that increase the leakage of fluid from capillaries. This includes:

• Increased hydrdostatic pressure- CCF, Cirrhosis, Fluid Overload, Pericarditis
• Decreased osmotic pressure due to low protein content (cirrhosis, liver failure, nephrotic syndrome, malabsorption)

Protein content less than 30g/L (less than 25g/L OHCM)

Question 15

What is an exudate and what level must the protein be able to be considered an exudate?

Answer 15

Exudates exude protein, they therefore occur often when there is an inflammatory process going on.

Causes include (Infection, Inflammation, Malignancy):
SLE, RA, Infection, Malignancy, Pneumonia, TB

Protein level >30g/L

Question 16

What is light’s criteria and what is it used for?

Answer 16

Light’s criteria is used to decide if an aspirate is an exudate and should be used for border line cases. Criteria are:

• Protein content >30g/L
• Aspirate Protein/Serum Protein>0.5
• Aspirate LDH/Serum LDH >0/.6
• Aspirate LDH >2/3 Serum LDH upper limit normal

Question 17

What can a low aspirate glucose be an indicator of? (<3.3mmol/L)

Answer 17

Empyema
TB
RA/ SLE
Malignancy

Question 18

What might a low aspirate pH be an indicator of? (pH<7.2)

Answer 18

Empyema
TB
RA/SLE
Malignancy

Question 19

What might a high aspirate LDH be an indicator of?

Recall Light’s Criteria regarding LDH

Answer 19

Empyema
TB
RA/SLE
Malignancy

Aspirate LDH/Serum LDH >0.6
Aspirate LDH> 2/3 ULN for Serum LDH

Question 20

What might a aspirate raised amylase be an indicator of?

Answer 20

Pancreatitis
Ruptured oesophagus
Carcinoma

Question 21

What immunology tests may be requested for a pleural effusion and what do they indicate?

Answer 21

ANA- SLE
RF- RA
Complement- Low in SLE, RA, Malignancy, Infection

Question 22

What is Meigs’ Syndrome?

Answer 22

Right sided pleural effusion seen with ovarian fibroma

Question 23

What is the usual pH of pleural fluid Below what pH should you consider empyema, malignancy, TB, SLE/RA?

Answer 23

7.6 is normal

Below 7.2/7.3 consider empyema, TB, malignancy, RA, SLE

Question 24

How do you manage a pleural effusion?

Answer 24

Find the cause and treat this
Symptomatic drainage

If no cause identified from aspiration (e.g. infection)- CT Thorax (and other imaging), VATS, Medical Thoracoscopy

Question 25

What are the two types of parapneumonic effusion?

Answer 25

Simple- common and usually sterile, resolve without intervention
Complex- pH<7.2 and infection likely or gram stain/culture +Ve. Requires ICD.
Empyema- Pus on diagnostic aspirate, requires PROMPT ICD

Question 26

Where should an ICD be inserted, describe the anatomical boundaries?

Answer 26

Safe Triangle
Lateral border of pectoralis major
Anterior border of trapezius
Level of the 5th ICS
Mid clavicular line

Question 27

How might recurrent pulmonary effusions be prevented?

Answer 27

Pleurodesis using talc (combines the visceral and parietal pleura). Can be done by:

• Talc insertion via ICD
• Talc via medical thoracoscopy
• Talc via VATS