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