UNILATERAL PLEURAL EFFUSION Flashcards
What is a pleural effusion?
Excess fluid in the pleural cavity.
What is it categorised by?
Divided by their protein concentration: transudates (<25g/L) and exudates (>35g/L)
What is a heamothorax?
blood in the pleural cavity – usually due to trauma
What is a Haemopneumothorax?
blood and air in the pleural cavity
What is an Empyema/pyothorax ?
pus in the pleural cavity – usually due to pneumonia
What is a Chylothorax?
chyle (lymph and fat) in the pleural cavity – usually caused by rupture of the thoracic duct
Aetiology of transudates
- May be due to increased venous pressure (HF, constrictive pericarditis, fluid overload)
- Or hypoproteinaemia (liver failure, cirrhosis, malabsorption, nephrotic syndrome)
- Hyperthyroidism
- Meig’s syndrome (right pleural effusion and ovarian fibroma)
Aetiology of exudates
• Mostly due to increased ‘leakiness’ of pleural capillaries secondary to infection, inflammation, malignancy
Due to pneumonia, TB, pulmonary infarction, RA, SLE, lymphoma, lung Cancer
Symptoms
- Asymptomatic – effusion has to be quite large to cause symptoms; approx >500ml
- Dyspnoea
- Pleuritic chest pain
Signs
- Decreased chest expansion
- Stony dull to percussion
- Diminished breath sounds
- Tactile vocal fremitus and vocal resonance decreased
- Tracheal deviation away from effusion – in large effusions; if associated lung collapse then deviated towards
- Mediastinal shift – suggests effusion >1L
- Bronchial breathing – where lung is compressed above effusion
- Signs of associated disease
- Above the effusion, the lung is compressed – may be bronchial breathing
- Look for aspiration marks and signs associated disease (Cachexia, clubbing, lymphadenopathy, radiation marks, mastectomy scars – malignancy; signs cardiac failure, RA, SLE (butterfly rash))
What are the investigations?
CXR
USS
Diagnostic aspiration
Pleural biopsy
What would expect a CXR to show?
- Small effusions blunt the costophrenic and costocardiac angles
- Larger effusions are seen as water-dense shadows with concave upper borders (a meniscus); a completely horizontal upper border = pneumothorax as well!
Why do we do a USS?
useful in guiding diagnostic or therapeutic aspiration
What is a diagnostic aspiration?
- Percuss upper border of effusion and go 1-2 intercostal spaces below it
- Local anaesthetic
- Insert needle just above rib (to avoid neurovascular bundle) and aspirate 10-30ml
- Send to lab for clinical chemistry, bacteriology, cytology and immunology if indicated
- Transudate = protein <30, exudate = protein >30
- Light’s criteria – more accurate diagnosis of transudate and exudate; compares blood protein vs fluid protein as some things like diuretics can affect protein content
- Empyema = pH <7.2 (acidotic), can sometimes also look like pus
What is LIGHTS criteria?
Satisfying any ONE criterium means it is exudative):
Pleural Total Protein/ Serum Total Protein > 0.5
Pleural LDH/ Serum LDH > 0.6
Pleural LDH > 2/3s of the upper limit of normal for serum LDH
When would you do a pleural biopsy?
if pleural fluid analysis still inconclusive; thoracoscopic or CT-guided biopsy with Abram’s needle
What is the management/treatment?
Treat underlying cause, drainage and pleurodesis
What is the only treatment for transudate?
Treat underlying cause
Why do you drain?
if symptomatic; best remove fluid slowly (<2L/24hrs); either via pleural tap or intercostal drain. Fluid is best removed slowly (<2L/24hr). Aspirate via IC drain or in same way as diagnostic tap
When do you do pleurodesis?
- if recurrent effusions with tetracycline, bleomycin or talc – may be helpful for recurrent effusions
Chemical injected into pleural space and causes inflammation of the membranes, helping them to stick together
Differential diagnosis?
Pneumothorax – hyperresonant to percussion; black on CXR; different underlying pathology
Prognosis
If cause is malignancy, the outlook is generally poor
