Pnemothorax Flashcards
what is the definition of pneumothorax?
Pneumothorax occurs when air gains access to, and accumulates in, the pleural space.
A primary spontaneous pneumothorax occurs in young people without known respiratory illnesses. A secondary spontaneous pneumothorax occurs in patients with pre-existing pulmonary diseases.
what is the epidemiology of pneumothroax?
More common in men
Smoking increases risk (especially for men)
what is the aetiology of pneumothorax?
Spontaneous: Smoking, family history, tall and slender, male, young age (BUT >55yrs for secondary), underlying disease (COPD, asthma, TB, infection, CF), structural abnormalities (Marfans, ED syndrome), homocystinuria, menstruation (catamenial pneumothorax) Traumatic: Penetrating or blunt chest injury Tension: Complication of above, more likely in: ventilated patients, trama, lung disease,blocked chest drain, NIV iatrogenic: Following invasive medical procedure
what are the risk factors for pneumothorax?
Smoking male (for primary spontaneous) Family history Tall and slender Under 40 Recent invasive medical procedure Chest trauma Acute severe asthma COPD TB AIDS related pneumocystis jirovecii infection Cystic fibrosis Lymphangioleiomyomatosis Birt-hogg-dube syndrome Pulmonary langerhans cell histiocytosis Erdheim-chester disease
what is the pathophysiology of pneumothorax?
Pneumothorax refers to gas within the pleural space. Normally, the alveolar pressure is greater than the intrapleural pressure, while the intrapleural pressure is less than atmospheric pressure. Therefore, if a 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 will continue until the pressure gradient no longer exists or the abnormal communication has been sealed. Because the thoracic cavity is normally below its resting volume, and the lung is above its resting volume, the thoracic cavity enlarges and the lung becomes smaller when a pneumothorax develops.
A tension pneumothorax is a medical emergency and occurs when the intrapleural pressure exceeds atmospheric pressure, especially during expiration, and results from a ball valve mechanism that promotes inspiratory accumulation of pleural gases. The build-up of pressure within the pleural space eventually results in hypoxaemia and respiratory failure from compression of the lung.
what are the key presentations of pneumothorax?
Chest pain Dyspnoea Ipsilateral reduced breath sounds Ipsilateral hyperinflation of hemithorax with hyperresonance on percussion Hypoxia Risk factors
what are the first line and gold standard investigations for pneumothorax?
Chest x-ray - a visible rim between the lung margin and chest wall, or surgical emphysema, absence of lung markings between the lung margin and chest wall, lung collapse = triangle and midline shift
FBC and clotting levels - correct any clotting abnormalities before treating
what are the differential diagnoses for pneumothorax?
Acute exacerbation of asthma or COPD
Pulmonary embolism
MI
how is pneumothorax managed?
Suspected tension:
Immediate decompression, high flow oxygen, chest drain
Confirmed primary spontaneous:
Small (<2cm between lung and wall) - observation and oxygen
Large - percutaneous aspiration, chest drain, oxygen, surgery
Confirmed secondary spontaneous:
Small (<1cm) - oxygen and observation in hospital
Moderate (1-2cm) - percutaneous aspiration, oxygen, chest drain
Large - chest drain, oxygen, surgery, pleurodesis
Confirmed traumatic:
Oxygen, observation, refer to thoracic surgeon
how is pneumothorax monitored?
Monitor for complications of chest drain insertion. Visceral injury is the most serious complication, but other more common complications include: Pain Intrapleural or wound infection Drain dislodgement or blockage Surgical emphysema.
what are the complications of pneumothorax?
Re-expansion pulmonary oedema
Talc pleurodesis-related ARDS
obstructive shock due to interference with ventricular filling
complications of chest drain - winging of the scapula
what is the prognosis of pneumothorax?
Recurrence is common especially in primary spontaneous cases
