Pleural Disease Flashcards
What is pleura composed of?
- Single layer of mesothelial cells
- Sub-pleural connective tissue
What is found between the visceral and parietal pleura?
- The pleural cavity
- Lubricated by 2-3ml of pleural fluid which has a 30-75% turnover per hour
What pressure moves fluid from the chest wall to the pleural cavity?
Systemic arterial pressure (4kPa), negative intra pleural pressure
What pressure moves fluid from the pleural cavity to the chest wall?
Plasma osmotic/oncotic pressure
What pressure moves fluid from the pleural cavity to the lungs?
Plasma osmotic/oncotic pressure
What pressure moves fluid from the lungs to the pleural cavity?
Pulmonary arterial pressure (1.5kPa), negative intra pleural pressure
Overall, what is the net movement of fluid due to pressure?
From systemic circulation through the pleura into the lungs
How high up does the pleura extend?
Above the 1st rib
How far down does the pleura extend?
Pleura found over the liver, spleen and kidneys
Pleural effusion
Abnormal collection of fluid in the pleural space
What are the symptoms of pleural effusion dependent on?
Depends on cause and volume of fluids
What symptoms can pleural effusion present with?
- Asymptomatic
- Increasing breathlessness
- Pleuritic chest pain
- Dull ache
- Dry cough
- Weight loss
- Malaise
- Fevers
- Night sweats
What do you need to enquire about when asking about symptoms relating to pleural effusion?
- Peripheral oedema
- Liver disease
- Orthopnoea
- PND
What are the 2 reasons for pleuritic chest pain due to pleural effusion?
- Inflammatory: early, may improve as fluid accumulates
- Malignancy: progressively worsening
What are the main signs of pleural effusion?
Chest on affected side:
- Decreased expansion
- Stony dullness to percussion
- Decreased breath sounds with band of bronchial breathing
- Decreased vocal resonance
What other signs might be present in pleural effusion?
- Clubbing
- Tar staining of fingers
- Cervical lymphadenopathy
- Increased JVP
- Trachea deviated away from effusion
- Peripheral oedema
What are the 2 ways the pleural effusions can be classed by cause?
- Exudates
- Transudates
What causes transudate pleural effusions?
An imbalance of hydrostatic forces influencing the formation and absorption of pleural fluid
What are the characteristics of transudate pleural effusions?
- Normal capillary permeability
- Usually but not always bilateral
What are the characteristics of exudate pleural effusions?
- Increased permeability of pleural surface and/or local capillaries
- Usually unilateral
For exam purposes how do you separate exudates and transudates?
- Transudates have pleural fluid protein of <30g/l
- Exudates have pleural fluid protein of >30g/l
What are the ‘very common’ causes of transudates?
- Left ventricular failure
- Liver cirrhosis
- Hypoalbuminaemia
- Peritoneal dialysis
What are the ‘less common’’ causes of transudates?
- Hypothyroidism
- Nephrotic syndrome
- Mitral stenosis
- Pulmonary embolism
What are the ‘rare’ causes of transudates?
- Constrictive pericarditis
- Ovarian hyperstimulation syndrome
- Meigs’ syndrome
What are the ‘very common’ causes of exudates?
- Malignancy (lung, breast, mesothelium, metastatic)
- Parapneumonic (consider sub-phrenic)
What are the ‘less common’ causes of exudates?
- Pulmonary embolism/infarction
- Rheumatoid arthritis
- Autoimmune diseases
- Benign asbestos effusion
- Pancreatitis
- Post-myocardial infarction/ cariotomy syndrome
What are the ‘rare’ causes of exudates
- Yellow nail syndrome
- Drugs
What drugs can cause exudates?
- Amiodarone
- Nitrofurantoin
- Phenytoin
- Methotrexate
- Carbamazapine
- Penicillamine
- Bromocriptine
- Pergolide
When is investigation not usually required for pleural effusion?
Transudates
When is investigation required regarding pleural effusion?
- If there is unusual features
- Failure to respond to appropriate treatment
What is used to confirm presence of effusion?
Chest radiograph
How much fluid is required before it is detectable on a chest X-ray?
At least 200ml
What can a contrast enhance CT of the thorax usually differentiate between?
Malignant and benign disease
What can be seen on a contrast CT which can differentiate between malignant and benign disease?
- Nodular pleural thickening
- Mediastinal pleural thickening
- Parietal pleural thickening >1cm
- Circumferential pleural thickening
- Other malignant manifestations in lung/liver
What is required for aspiration of pleural effusion?
- 50ml syringe 21G needle
- Lignocaine anaesthesia
- Sterile universal containers
- Blood culture bottles
What are the possible complications from aspiration/biopsy of pleural effusion?
- Pneumothorax
- Empyema
- Pulmonary oedema
- Vagal reflex
- Air embolism
- Tumour cell seeding
- Haemothorax
What ward analysis can be carried out during pleural aspiration?
Look and sniff
What can you tell by looking and sniffing contents of a pleural aspiration?
- Foul smelling: anaerobic empyema
- Pus: empyema
- Food particles: oesophageal rupture
- Milky: chylothorax
- Blood stained: malignancy
- Blood: haemothorax, rupture
What does a pH of< 7.2 for the contents of pleural aspiration suggest?
Infection