Pleural disease Flashcards
What is pleural effusion?
A collection of fluid in the pleural space
What is the mechanism by which pleural effusion comes about?
Imbalance between productions (mostly by parietal pleura) and absorption (by pleural lymphatics in the parietal pleura)
What are the two types of effusion?
Transudate
Exudate
What is transudate effusion?
Non inflammatory
Low protein content
What is exudate effusion?
Inflammatory fluid
High protein content
What are the common causes of transudate effusion?
Left ventricular failure
Liver cirrhosis
What are the common causes of exudate effusions?
- Malignancy (pulmonary and non-pulmonary)
- Parapneumonic effusions, empyema
- Tuberculosis
What are the less common causes of exudate effusion?
Pulmonary embolism
Connective tissue disease
Benign asbestos pleural effusion
Pancreatitis
Post-myocardial infection
Post-coronary artery bypass graft
Haemothorax, chylothorax
What are the rare causes of exudate effusion?
Yellow nail syndrome
Drugs
Fungal infections
What are the less common causes of transudate effusion?
- Hypoalbuminemia
- Nephrotic syndrome
- Mitral stenosis
What are the rare causes of transudate effusion?
- Constrictive pericarditis
- Urinothorax
- Meigs’ syndrome
What do you use to distinguish between transudate and exudate?
Lights criteria
What are the points of lights criteria?
Protein: pleural fluid/serum fluid > 0.5
LDH: pleural fluid/serum fluid > 0.6
Pleural fluid: LDH > 2/3 upper limit of normal serum LDH
What is a pneumothorax?
Air in the pleural cavity
What causes primary/secondary spontaneous pneumothorax?
Occur due to blebs (weak areas on lung surface) which rupture spontaneously and leak air into pleural cavity.
What makes a pneumothorax secondary?
Pre-existing lung conditions
e.g. interstitial lung disease, COPD, CF, asthma, pleural endometriosis, genetic disorders
How does a pneumothorax present?
Chest pain
Breathlessness
Tachypnoeic
Hypoxic
Reduced chest wall movement
Reduced breath sounds
Hyper resonant during percussion
**examination may be normal
Who is at risk?
Tall thin young men
Underlying lung disease
History of biopsy/line insertion/mechanical ventilation
What investigations are done to get diagnosis?
CXR
US
CT thorax
What are the management options for a pneumothorax?
Observe
- If patient well and pneumothorax is small
Aspiration
- If pneumothorax is over 2cm in size
- If patient is well
Chest drain insertion
- Channel allows air to be drained
- Left in place until pneumothorax resolves
- For large pneumothoraxes
Surgery
- Recurrent events
- Unresolving
What are the causes of pneumothorax?
Spontaneous
Traumatic
Iatrogenic
Tension
How do traumatic pneumothoraxes occur?
As a result of injury to the chest wall of the lung
e.g. fractured ribs puncturing the lung, knife injury and penetrating would to chest wall.
How do iatrogenic pneumothoraxes occur?
Result of biopsy of lung
Patient on ventilator
Inserting central venous line
Pacemaker
How do tension pneumothoraxes occur?
- Can be life threatening emergency
- Air in pneumothorax builds up to the point it causes pressure and pushes central structures and squashes opposite lung
- Applies pressure on heart so more difficult to fill so BP drops
- May require emergency aspiration
- Less common and can happen with ventilation or trauma patients
What is mesothelioma malignancy?
A cancer of the pleura (primary malignancy)
What are the causes of mesothelioma malignancy?
Spontaneous
Exposure to asbestos fibres
What occupations are most at risk of malignant mesothelioma?
Plumbers, electricians, shipbuilding, power plants, boilers, engines
What is the pathology of mesothelioma?
Inhaled asbestos fibres reach the pleura and cause inflammation provoking tumour formation.
Cycle of inflammation and repair = tumour
How long is the latency period for mesothelioma?
20-40 years
What are the clinical signs of mesothelioma?
Breathlessness
Chest pain
Weight loss
Clubbed fingers
Signs of pleural effusion
How do you diagnose mesothelioma?
CXR
CT thorax
Biopsy
What signs are you looking for when diagnosing malignant mesothelioma?
Thickened pleura
Pleural nodules or masses
Pleural plaques
An effusion
Soft tissue infiltration
What are the management options for malignant mesothelioma?
- Limited treatment options
- Palliative, survival is poor
- Treating the effusion
- Chemotherapy - only for select few, small survival benefit
- Recruitment to trails via MDTs
- Palliative surgery in select patients
What are the most common sites of metastasis (secondary tumour) of malignant mesothelioma?
Interparental
Breast
Ovarian
Renal
GI tract
Thyroid
What investigations are done for pleural effusion?
Ultra sound
CXR
CT thorax
Describe how ultra sound can be used in pleural effusion?
Mark site for aspiration
Assess pleura
Can be done at bedside
More sensitive than CXR
Describe how CXR can be used in pleural effusion?
Need about 100-200ml of fluid for effusion to become visible on CXR
Is accessible
Easy to interpretate
Describe how CT thorax can be used in pleural effusion?
For complex effusions
Visualising the pleura, vascular and mediastinal structures in greater detail
Can identify pockets of fluid
Identify nodules/lumps/bumps/thickening of the pleural surface
Explain the process of pleural fluid analysis and what is analysed?
Aspirate fluid
- Inspect fluid -> Pus? Blood?
- pH using an ABG: if pH < 7.2 in presence of pneumonia then chest drain is needed. As its likely that this will form pus and thus be more difficult to control.
What is done in the management of pleural effusion?
a) if pH < 7.2
b) if effusion transudate
c) if effusion exudate
a) If with pneumonia, pus or blood = chest drain.
b) Treat underlying cause.
c) Unless cause if identified will need further investigations e.g. imaging or/and pleural biopsy.
What are pleural plaques?
Areas where the pleura becomes thickened
What is empyema?
Pockets of pus that collect inside the pleural cavity
