A pneumothorax refers to air in the pleural space.
Consider when ever sudden
- Pleuretic chest pain
Can be asymptomatic
Pneumothorax in the absence of underlying lung disease. Mainly occur among tall, young, smoking males. These are not strictly idiopathic as they are often due to to leakage of air from apical blebs in lung.
- Some mutations of the FLCN gene are associated with a highly increased incidence as in Birt-Hogg-Dube syndrome.
- The renal malignancy risk comes on a mean of 10 years later than the pneumothorax so diagnosis may allow effective renal screening
- Marfan's syndrome
- Ehlers-Danlos syndrome
- Alpha-1 antitrypsin deficiency
Due to pre-existing pathology: eg
- Bullae in emphysema
- Interstitial lung disease
See a list of causes
- Traumatic; esp. penetrating trauma or blunt trauma causing rib fractures
- After fine needle lung aspiration (hint the CT lung can guide management here)
- Post-CABG or thoracotomy
- As a complication of central venous access or Thoracocentesis
Trapped lung is when the lung can not expand fully due to an endobronchial obstruction or a thick visceral peel. This is not the same as a pneumothorax as the thoracic cavity is at less than atmospheric pressure.
- Tension pneumothorax
- Decompensation in patients with pre-existing poor respiratory reserve.
- Chest X-ray
- Expiratory films are not usually necessary but you will miss about 10% of (minor) pneumothoracies without them
- The percentage pneumothorax should be calculated as:
%Pneumothorax = ((WidthHemithorax)3 − (WidthLung)3) / (WidthHemithorax)3 * 100
- CT chest is todays gold standard
- Demonstrates complex and small pneumothoracies
- Excludes conditions such as bullae
Essentially, treatment depends on the underlying aetiology, the severity of symptoms and the size of the pneumothorax. Small, largely asymptomatic primary pneumothoraces may simply be observed with serial CXRs. Moderately sized ones may require aspiration of air and larger ones may require intercostal chest drains.
Recurrent Primary Pneumothoraces
- VATS pleurectomy and pleurodesis +/- bullectomy
- Pleurodesis is the intentional irritation of the pleural cavity to encourage it to obliterate and fuse. Chemicals that have been used include tetracycline and talc with graded talc being shown to be safe.
- Pleurectomy effectively results in fusion of the visceral surface of the lung directly to the chest wall.