Pneumothorax Flashcards
Who is affected more - males or females?
Males.
What are the different types of pneumothoraces?
· Primary spontaneous pneumothorax - young people without known respiratory illness.
· Secondary spontaneous pneumothorax - patient’s with pre-existing pulmonary diseases.
· Tension pneumothorax - medical emergency for decompression.
What is the pathophysiology of a pneumothorax?
· Air gains access to and accumulates in the pleural space.
· If communication develops between an alveolus and the pleural space, OR, between the atmosphere and the pleural space, gases will follow the pressure gradient and flow into the pleural space.
· This flow continues until the pressure gradient no longer exists or the communication has been sealed.
· The lung then becomes smaller as the thoracic cavity enlarges.
What normally happens to the pressure in the lungs?
· Alveolar pressure is higher than the intrapleural pressure.
· Intrapleural pressure is less than atmospheric pressure.
What happens in a tension pneumothorax?
· Medical emergency.
· Intrapleural pressure exceeds atmospheric pressure, especially during expiration.
· Build up of pressure within the pleural space results in hypoxia and respiratory failure from compression of the lung.
What is the aetiology of a primary spontaneous pneumothorax?
· Without preceding trauma or precipitating event.
· Patients without clinically apparent pulmonary disease.
· Smoking:
- Increases the likelihood of spontaneous pneumothorax by 22 times in men.
- Increases the likelihood of spontaneous pneumothorax by 8 times in women.
· Marfan’s syndrome.
· Homocystinuria.
· FHx of pneumothorax.
What is the aetiology of a secondary spontaneous pneumothorax?
· Complication of an underlying pulmonary disease.
· COPD from cigarette smoking - 70% of these cases.
· CF.
· TB.
What is the aetiology of a traumatic pneumothorax?
Penetrating or blunt injury to the chest.
How does a tension pneumothorax affect the other pneumothoraces?
Can complicate primary/secondary/traumatic pneumothoraces.
List the common risk factors associated with a pneumothorax.
· Cigarette smoking.
· FHx of pneumothorax - PSP.
· Tall and slender body build - PSP.
· Age <40 years - PSP.
· Recent invasive medical procedure - CVC insertion, thoracentesis etc.
· Chest trauma.
· Acute severe asthma, COPD, TB, CF - SSP.
· Marfan’s.
· Homocystinuria.
· Primary lung cancer and metastatic cancer to the lungs.
What are the common signs and symptoms related to a pneumothorax?
· Chest pain - same side as pneumothorax.
· Dyspnoea - degree depends on size of pneumothorax and severity of pre-existing lung disease.
· Hyperexpanded ipsilateral hemithorax - degree depends on the size of the pneumothorax and whether a tension pneumothorax develops.
· Hyper-resonant ipsilateral hemithorax - hyper-resonance on percussion of the affected side.
· Ipsilateral absent or diminished breath sounds - diminished or absent breath sounds on the affected side.
· Trachea shifted to contralateral side - tension pneumothorax.
What investigations would you do if you suspected a patient had a pneumothorax?
· CXR.
· CT chest.
· Chest USS.
· Bronchoscopy.·
What would you look for on a CXR?
· Presence of the visceral pleural line.
· Lung atelectasis.
· Loss of volume.
Differentials?
· Acute asthma exacerbation. · Acute COPD exacerbation. · PE. · Myocardial ischaemia. · Pleural effusion - dullness to percussion and meniscus sign at the costophrenic angle on upright CXR. · Bronchopleural fistula. · Fibrosing lung disease. · Oesophageal perforation.
What is the treatment for a tension pneumothorax?
· Immediate needle decompression - 14-gauge cannula at the 2nd intercostal space, mid-clavicular line.
· Oxygen.
· Tube thoracostomy.
