Pleural Effusion

Question 1

Define pleural effusion

Answer 1

Fluid collection between the parietal and visceral pleural surfaces of the thorax

Question 2

Aetiology of pleural effusion

Answer 2

Exudate (>30g protein)

Infection
- pneumonia (most common exudate cause),
- tuberculosis
- subphrenic abscess
connective tissue disease
- rheumatoid arthritis
- systemic lupus erythematosus
neoplasia
- lung cancer
- mesothelioma
- metastases
pancreatitis
pulmonary embolism
Dressler’s syndrome
yellow nail syndrome

Transudate (<30g protein)
heart failure (most common transudate cause)
hypoalbuminaemia
- liver disease
- nephrotic syndrome
- malabsorption
hypothyroidism
Meigs’ syndrome (R-sided pleural effusion + ascites + ovarian tumour)

Question 3

Symptoms and signs of pleural effusion

Answer 3

Dyspnoea
Non productive cough
Chest pain

Reduced chest expansion
Dullness to percussion
Quiet breath sounds
Decreased/absent tactile fremitus

Question 4

investigations for pleural effusion

Answer 4

Urine dip: ?nephrotic syndrome

FBC
U&Es
LFTs
CRP
Clotting
Blood culture

CXR: meniscus sign
US-guided pleural aspiration
Contrast CT
Echo: ?CHF
BAL: ?Cellularity
EBUS: ?Sarcoid, TB

Question 5

How do you interpret pleural effusion tap

Answer 5

Exudate = >30g/L protein
Transudate = <30g/L protein
Use Light’s criteria if 25-35g/L protein (helps differentiate causes). An exudate is likely if:
- Pleural fluid protein / serum protein >0.5
- Pleural fluid LDH / serum LDH >0.6
- Pleural fluid LDH > 2/3rds ULN serum LDH

Empyema: pH <7.2 | LDH raised | glucose low
low glucose: rheumatoid arthritis, tuberculosis
raised amylase: pancreatitis, oesophageal perforation
heavy blood staining: mesothelioma, pulmonary embolism, tuberculosis

Question 6

Management for pleural effusion

Answer 6

(1) Pleural effusion with aspirate
- turbid/cloudy, tests +ve on MC&S, pH <7.2 → chest drain
N.B. can use an ABG to ascertain if the pH is acidic quickly

(2) Treat underlying cause (i.e. ABx for pneumonia, furosemide for AHF, etc.)

Question 7

Management for recurrent pleural effusion

Answer 7

Recurrent aspiration
Pleurodesis
Indwelling pleural catheter
Drug management (i.e. opioids for SOB)

Question 8

Complications of pleural effusion

Answer 8

Atelectasis/lobar collapse
Pneumothorax following thoracentesis
Re-expansion pulmonary oedema
Pleural fibrosis
Pseudochylothorax
Trapped lung