20 Pneumothorax and Pleural Effusion Flashcards
A pneumothorax is caused when the chest wall or the lung is breached. Explain how:
Communication created between pleural space and atmosphere
Air drawn in due to relatively negative pressure in pleural space
Lung collapses due to unopposed elastic recoil
Define a pneumothorax
Presence of air between the visceral and parietal pleura
How can a pneumothorax be caused (ie where does the air come from- orgin of pathology)
How is a primary, spontaneous pneumothorax created? What are the risk factors for it?
Most cases: small-subpleural bleb/bulla that bursts
Risk factors:
- Smoking (increases risk x9)
- Common in young, tall, thin males
List some of the causes of a secondary pneumothorax:
(3 categories: underlying lung disease, trauma, iatrogenic)
With a simple pneumothorax, what is likely to be the presenting history? What condition might the history be similar to?
Sudden onset
Pleuritic chest pain and breathlessness
+/- history of lung diseasse/trauma
Similar history: pulmonary embolism
On examination, what are you going to find with a simple pneumothroax (think resp examination)
What pathology does this x-ray show? Explain your reasoning:
What pathology is shown in the following CT scan?
If a patient has a simple pneumothorax, how should it be treated?
- Small: might seal itself off- air ends up in blood stream
- Small: needle aspiration might be suficient
- Large: insertion of chest drainage
How do you know where to insert a chest drainage for a large pneumothorax?
- 5th intercostal space
- Mid-axillary line
- Just above 6th rib
How does the chest drain work?
Connection between chest drain and underwater seal
On expiration- won’t have bubbles in water once healed
On inspiration- water seal prevents entrapment of room air
Define a tension pneumothorax and how can it be caused?
Any size of pneumothorax causing mediastinal shift and cardiovascular collapse
Cuased by an aetiology (anything can progress to it
A tension pneumothorax can lead to hypoxaemia and haemodynamic compromise which is life threatening. Explain how:
- Mediastinal shift- compress normal lung
- Increased intrapleural pressure- can’t draw air in
- Venous return=impaired
- CO drops
What are the signs and symptoms of a tension pneumothorax?
What is shown in the following x-ray? Why should this x-ray not have been taken?
With tension pneumothorax- diagnosis=clinical
NO TIME for CXR for confirmation- need emrgency decompression of chest
How is a tension pneumothorax treated?
What is a pleural effusion?
Excess of fluid in pleural cavity
Imbalance in normal rate of fluid production and absorption
Fluid= transudate/exudate
Define the following: haemothorax, chylothorax, empyema
How is pleural fluid usually produced and absorbed? What forces is this dependent on?
Production: 2400ml by paritel pleura
Absorption: by lymphatics
Depends on:
STARLING FORCES
Hydrostatic pressure and colloid osmotic pressure
Differentiate between the possible caused of a transudate pleural effusion and an exudate pleural effusion.
When testing a sample of transudate vs exudate- how can we tell which is which?
What history is a patient with a pleural effusion likely to present with?
- Breathlessness- gradual onset (days)
- Chest pain- pleuritic
- +/- features of causative disease eg lung malignancy/congestive cardiac failure
What are you likely to find on examination with a pleural effusion?
What is shown in the following x-ray?
Pleural effusion in right lung
If a patient has a suspected pleural effusion why is it useful to do a CT scan?
Detect underlying pathology and confirm effusion
In general is a bilateral pleural effusion more likely to be due to exudate or transudate?
Bilateral= more likely transudate and more systemic conditions
Unilaterall= more likely to be exudate as more localised
How do we reach a diagnosis of the cause of a pleural effusion?
How do we treat a pleural effusion?
- Treat underlying condition
- If very symptomatic–> chest aspiration
- Recurrent effusion- may require:
- indwelling pleural catheter
- Pleurodesis: obliteration of pleural space- visceral and parietal= adherent
