Pleural Diseases

Question 1

What is the difference between a transudate and an exudate, and how are they identified?

Answer 1

Transudates form from an imbalance of hydrostatic forces influencing the formation and absorption of luid
There is normal capillary permeability and they are usually (but not always) bilateral.

Exudates are usually unilateral and form due to permeability of the pleural surface and/or local capillaries.

Transudates generally have <30g/L of protein
Exudates generally have >30g/L

Exudate if 1 or more criteria met:
Pleural/serum protein >0.5
Pleural/serum LDH >0.6
Pleural LDH >0.66 of upper limit of serum LDH

Question 2

What are common causes of transudates and common causes of exudates?

Answer 2

Transudate:

• LV failure
• Liver cirrhosis
• Hypoalbuminaemia
• Peritoneal dialysis

Exudate:

• Malignancy
• Parapneumonic

Question 3

What are symptoms of a pleural effusion?

Answer 3

Asymptomatic if small and accumulates slowly.

Increasing SOB, can be over days, weeks, months
Pleuritic chest pain
Dull ache
Dry cough - especially in rapid
Weight loss
Malaise, fevers, night sweats

Enquire about peripheral oedema, liver disease, orthopnoea/PND

Question 4

What are some signs of a pleural effusion?

Answer 4

Chest on affected side has:

• decreased expansion
• stony dullness on percussion
• decreased breath sounds (bronchial breathing)
• decreased vocal resonance

Clubbing/tar staining
Cervical lymphadenopathy
Increased JVP
Trachea away from large effusion
Peripheral oedema

Question 5

Investigations performed in pleural effusions?

Answer 5

Usually not required for transudates - clinical presentation usually characteristic
Investigate if unusual features or failure to respond to treatment

CXR - confirm effusion (200mL before can be seen on x-ray)
CT thorax - differentiates between malignant/benign diseases
Pleural aspiration and biopsy
- 4 biopsies (3 in formaldehyde + 1 in saline for TB)

Ward analysis of aspiration

• foul = anaerobic bacteria
• bus = empyema
• food = oesophageal rupture
• milky = chylothorax (usually lymphoma)
• blood = malignancy? haemothorax? trauma?

Lab does biochemistry, microbiology, cytology

No diagnosis?
Thoracoscopy/VATS
- direct inspection of pleura

Question 6

Treatment for a pleural effusion?

Answer 6

Treatment directed at cause

• chemotherapy
• anti-TB
• corticosteroids

Pallative in malignancy
- repeated pleural aspirations

Pleurodesis

• 4th intercostal, mid-axillary
• drain no faster than 500mL/hour
• drain til dry, check with CXR
• if not expanded, apply suction
• if still not expanded, remove drain

Perform chemical pleurodesis
Surgical pleurodesis also a possibility

Question 7

What are the general causes of a pneumothorax?

Answer 7

Primary/secondary spontaneous or non-iatrogenic/iatrogenic traumatic
Any can cause a tension pneumothorax

Question 8

What tends to cause spontaneous pneumothoraces?

Answer 8

Primary - no apparent disease
- happens in young, tall, thin males

Secondary to pre-existing lung disease
COPD common, asthma also
TB, CF, fibrosis etc can all cause PTX

Question 9

What causes traumatic pneumothoraces?

Answer 9

Non-iatrogenic
- penetrating/blunt chest injury

Iatrogenic
- pleural aspiration, subclavian cannulation, biopsies, acupuncture

Question 10

Symptoms of a pneumothorax?

Answer 10

Asymptomatic if small and individual has good inspiratory reserve.
Acute and worsening SOB
Pleuritic chest pain
Extreme SOB
- if in someone previously fit, suspect tension pneumothorax

Question 11

Signs of pneumothorax?

Answer 11

May be no signs if small
Surgical emphysema if significant air leak
Non-tension - trachea deviated to affected side
- affected side decreased expansion, hyper-resonant, decreased breath sounds
Tension - tracheal deviation away from affected side
- haemodynamic compromise
- increased JVP

Question 12

Treatment for a pneumothorax?

Answer 12

Depends on type
Tension?
Small? Large?
Primary or secondary?

In tension, cannula 2nd intercostal midclavicular
- reinsert intercostal chest drain

Small primary with no SOB?
- observe, repeat CXR - if no change then hole is sealed, discharge, review

Primary with SOB?
- aspirate
- lignocaine on 2nd intercostal midclavicular
- 50mL syringe, venflon, 3 way tap, tube to water
- aspirate until feel lung on tip of venflon or >3L has come out (persistent leak)
Successful? - CXR and observe
Unsuccessful? - chest drain

Secondary with SOB?

• could try to aspirate if small
• intercostal (4th) chest drain
• small bore
• use large bore if surgical emphysema
• underwater seal

After an intercostal chest drain, consider clamping, Devereux prefers to clamp
High volume low pressure suction on drain if lung fails to reinflate after 48hrs

Talc poudrage or pleurectomy in recurrent PTX

Question 13

What are the three types of asbestos and which are the most dangerous?

Answer 13

White
Brown
Blue

White most common
Blue most dangerous

Disease occurs 20-40 years after exposure

Question 14

What is mesothelioma?

Answer 14

Pleural malignancy
80% due to malignancy

Can also occur in peritoneum

Question 15

What is the clinical presentation of mesothelioma?

Answer 15

SOB

Chest wall pain

Question 16

What would radiograph look like?

Answer 16

Usually unilateral

Diffuse or localised pleural thickening.