9.3 & 9.4 Pleural Effusions

Question 1

Define pleural effusion

Answer 1

Abnormal/excess fluid in pleural space

Question 2

Describe the three broad mechanisms of pleural effusion

Answer 2

• Transudative
• Exudative
• Disruption of fluid-containing structure within thoracic cavity

Question 3

List some of the most common causes of pleural effusion. Which is the most common?

Answer 3

• Heart failure (most common)
• Malignancy
• Infection
• Post-surgical

Question 4

Is pleural effusion more common in men or women? Does this differ between aetiologies?

Answer 4

• Overall, same
• However, differs between aetiologies

Question 5

Is pleural effusion more common in adults or children?

Answer 5

Adults

Question 6

What % of pleural effusion cases are considered idiopathic?

Answer 6

25%

Question 7

What symptoms do patients commonly present with when they have pleural effusion? Why?

Answer 7

• Shortness of breath (increased weight of fluid, mechanical strain on diaphragm and chest wall)
• Chest pain (usually due to parietal pleura inflammation)
• Cough (mechanical effects detected by airways)

Question 8

True or false: pleural effusion patients never present with abnormal examination findings

Answer 8

• False
• Sometimes they do, sometimes they don’t

Question 9

List some common examination findings for pleural effusion

Answer 9

• Clubbing (cancer)
• Tar staining (smoking -> cancer)
• Enlarged lymph nodes (infection)
• Chest wall scars
• Radiation burns and mastectomy (cancer?)
• JVP (heart failure)
• Evidence of arthropathy (rheumatological causes)

Question 10

Chest expansion findings pleural effusion

Answer 10

Reduced expansion ispilateral to effusion

Question 11

Percussion findings pleural effusion

Answer 11

“Stony” dull

Question 12

Auscultation findings pleural effusion

Answer 12

Absent or reduced breath sounds

Question 13

Investigations for suspected pleural effusion

Answer 13

• Observations (RR, HR, BP, SpO2)
• Blood test (WCC, CRP, Troponinin, D-Dimer)
• ECG
• CXR
• CT

Question 14

Describe various pleural fluid sampling/drainage procedures for pleural effusion

Answer 14

Diagnostic thoracentesis: Small volume of pleural fluid aspirated

Therapeutic thoracentesis: larger volume (usually >500mL) drained

Chest drain insertion: thoracostomy

Question 15

What is the recommended first line treatment approach for pleural effusion? Why?

Answer 15

• Large volume aspirate (don’t leave tube in) -> 1-1.5L
• It enables testing of fluid for aetiology, tests how quickly fluid will refill, gauges symptomatic benefits, and helps to identify a non-expansile lung

Question 16

What type of pleural effusion does low viscosity, straw-coloured fluid often suggest?

Answer 16

Transudate (but it can still be paucicellular exudate)

Question 17

What does serosanguinous fluid suggest in pleural effusion?

Answer 17

No real diagnostic value

Question 18

What does frank blood fluid in pleural effusion suggest?

Answer 18

Usually from malignant effusion, but could have other causes as well

Question 19

What does milky/turbid pleural effusion suggest?

Answer 19

Infection/chylothorax

Question 20

What does putrid smelling pus on pleural effusion suggest?

Answer 20

Infection. Likely from anaerobes

Question 21

What does urine-smelling pleural effusion indicate?

Answer 21

Urinothorax

Question 22

Is the criteria for classifying pleural effusions more likely to misdiagnose transudates or exudates? Why?

Answer 22

• More likely to mis-classify transudates as exudates
• This is because exudates are more severe

Question 23

Light’s criteria are the most common criteria used to classify pleural effusions. What are the criteria, and how many need to be fulfilled for it to be exudative?

Answer 23

1. If pleural fluid protein > 0.5 of serum protein
2. If pleural fluid LDH > 0.6 of serum LDH
3. If pleural fluid LDH >2/3 of laboratory normal value

Question 24

What does low pH of pleural fluid in pleural effusion suggest?

Answer 24

Malignancy and/or infection

Question 25

Under normal circumstances, can glucose diffuse across the pleura? How does this impact glucose levels?

Answer 25

- Yes, it can diffuse freely - Usually, pleural fluid glucose levels are same as blood glucose levels

Question 26

Under what circumstances could pleural fluid contain low glucose?

Answer 26

- Increased utilization - decreased diffusion due to pleural thickening

Question 27

What is the role of cell count testing in pleural effusion?

Answer 27

Differentiate between infection/inflammation and malignant aetiology.

Question 28

What is the role of cytology testing in pleural effusion?

Answer 28

Tests for malignancy

Question 29

What ages are pleural infection more common in, and is it more common in men or women?

Answer 29

- More common in elderly and childhood. - More common in men (twice as common)

Question 30

Mortality rates of pleural infection, including normal and immunocompromised/elderly:

Answer 30

Overall: 20% Elderly/immunocompromised: 30%

Question 31

List the four aetiologies of pleural infection (hint: it kind of resembles those of pneumonia)

Answer 31

- Community-acquired - Hospital-acquired - Iatrogenic - Other

Question 32

List some types of pleural infection whose aetiology falls under "Other"

Answer 32

- Oesophageal leak/rupture - Spontaneous bacterial empyema - Translocation from abdominal/sub-diaphragmatic infection

Question 33

Additional exam findings in pleural effusions associated with pleural infection

Answer 33

- Patients may look unwell - Diaphoretic - Fever

Question 34

In what % of infective pleural effusion is fluid culturing positive?

Answer 34

Only 50-60%

Question 35

Uncomplicated vs complicated para-penumonic effusion

Answer 35

- Both have no pus - Uncomplicated has normal pH/glucse, whereas complicated has abnormal - Complicated may also have culture positive readings and septations, uncomplicated has neither

Question 36

Describe the two main pillars of pleural infection management, and what is done for both

Answer 36

Pillar 1: Eradicate infection - Broad-spectrum antibiotic Pillar 2: Removed infected fluid - Chest tube - Fibrinolytics + mucolytics If these don't work: - Surgery

Question 37

Which agent is used for lysis of pleural adhesions? What type of drug is it?

Answer 37

Alteplase (thrombolytic)

Question 38

Which agent is used to decrease viscosity of infected pleural fluid

Answer 38

Pulmozyme

Question 39

Roughly what percentage of pleural effusions are malignant?

Answer 39

22% -> 1/5 is close enough to remember

Question 40

What % of cancers are complicated by malignant pleural effusion?

Answer 40

15%

Question 41

Strictly speaking, which cancers can cause malignant pleural effusion?

Answer 41

Literally any of them, if they spread

Question 42

List the four most common cancers that cause malignant pleural effusion, and specify the most common

Answer 42

- Lung cancer (most common) - Breast cancer - Mesothelioma - Lymphoma

Question 43

Is malignant pleural effusion more common in lung cancer or mesothelioma?

Answer 43

Mesothelioma (90% vs 50%)

Question 44

Are the examination findings for malignant pleural effusion very consistent?

Answer 44

- No - They can vary widely depending on what stage of disease the patient is in

Question 45

Investigations for malignant pleural effusion

Answer 45

- Vitals - Comprehensive bloods - Imaging (CXR, Thoracic ultrasound, CT, +/- PET scan) - Pleural fluid sampling - Pleural biopsy

Question 46

Describe pleural fluid characteristics in malignant pleural effusion

Answer 46

- Clear, blood-stained, or cloudy - No smell - pH may be normal or low - Protein: usually high - LDH: normal/elevated

Question 47

Does malignant pleural effusion always require intervention?

Answer 47

- No - Sometimes, systemic therapy will reduce the effusion

Question 48

Management options for malignant pleural effusions

Answer 48

- Thoracentesis - Intercostal catheter (temporary) - Indwelling pleural catheter - long-term - Surgical (Video-assisted surgery, decortication, pleurodesis)

Question 49

Describe indwelling pleural catheters

Answer 49

- Stay in patient - Intermittently, nurse can come to patient's house and drain the fluid

Question 50

What % of malignant pleural effusion cases show re-accumulation following drainage?

Answer 50

70-90%

Question 51

What occurs during video-assisted thoracoscopy surgery (VATS)

Answer 51

- Drain fluid - Take biopsies - Administer talc - Place a drain into patient