What is pleura composed of?
- Sub-pleural connective tissue
What is found between the visceral and parietal pleura?
- 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?
What do you need to enquire about when asking about symptoms relating to pleural effusion?
What are the 2 reasons for pleuritic chest pain due to pleural effusion?
- Malignancy: progressively worsening
What are the main signs of pleural effusion?
Chest on affected side:
What other signs might be present in pleural effusion?
What are the 2 ways the pleural effusions can be classed by cause?
- 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?
- Usually but not always bilateral
What are the characteristics of exudate pleural effusions?
For exam purposes how do you separate exudates and transudates?
- Exudates have pleural fluid protein of >30g/l
What are the ‘very common’ causes of transudates?
What are the ‘less common’’ causes of transudates?
What are the ‘rare’ causes of transudates?