what is a pneumothorax?
an abnormal collection of air in the pleural space - between the lung and the chest wall
what is the difference between primary and secondary pneumothorax?
primary - no underlying cause
secondary - underlying lung disease e.g. COPD
What is a tension pneumothorax?
a one way valve formed, allowing more and more air into the pleural space. this is a medical emergency
what usually causes primary spontaneous pneumothorax?
rupture of a pleural ‘bleb’ - the bleb is often from congenital defect in the tissue of the alveolar wall.
Who is more common to have a primary spontaneous pneumothorax?
tall young men
what are risk factors for pneumothorax?
smoking
family history
marfan syndrome
homocystinurea
what are the causes for secondary pneumothorax?
COPD cystic fibrosis lung malignancy pneumonia TB
How does a pneumothorax usually present?
- sudden onset SOB
- pleuritic chest pain (usually on side of pneumothorax)
- reduced breath sounds
- hyper-resonance on percussion
- hypoxia
What additional signs will a simple pneumothorax present with?
- air in the pleural space, but volume not increasing
- on CXR - lung collapse may be visible
What are the clinical features of a tension pneumothorax?
- pleuritic chest pain
- breathlessness
- tracheal deviation (away from the side of pneumothorax)
- reduced breath sounds in affected area and hyper-resonant on percussion
- air in the pleural space, and the volume continuing to increase
- rapid increase of intra-thoracic pressure. this reduces venous return to the heart and causes cardiac arrest if not treated quickly
How do you differentiation a simple pneumothorax from a tension pneumothorax?
- worsening clinical signs and symptoms
- tracheal deviation
- haemodynamically unstable (hypotensive, tachycardia, elevated resp rate)
what are the complications of a pneumothorax?
compression of the mediastinum = decreased cardiac output (compressed heart), increased heart rate, jugular vein distension, cardiac arrest
what investigations would be done for pneumothorax?
(if tension then clinical diagnosis (hopefully))
- Chest X-ray and CT
- ultrasound
- blood gas (hypoxia, usually normal CO2, respiratory alkalosis)
How do you treat a simple pneumothorax with a rim of air <2cm?
- consider observation for 4-6 hours and repeat CXR to ensue it is not progressing
- discharge on advice (no exercise, return if breathless)
- evaluate and re-x-ray at 2 week intervals until air is reabsorbed
- recommend patient avoids air travel for 2 weeks after resolution
How do you treat a primary pneumothorax - SOB + rim of air >2cm on CXR?
- give oxygen
- if acutely unwell (i.e. haemdynamically unstable) then attempt aspiration (2ND INTERCOSTAL SPACE, MIDCLAVICULAR LINE), if unsuccessful then repeat. if unsuccessful, consider chest drain, once decompressed will need a chest drain to continue decompression
- if not haemodynamically unstable: chest drain
- admit to ICU if appropriate, admit to hospital
How do you treat a secondary pneumothorax - SOB + rim of air >2cm on CXR?
- give oxygen
- if acutely unwell (i.e. haemdynamically unstable) then attempt aspiration (2ND INTERCOSTAL SPACE, MIDCLAVICULAR LINE), if unsuccessful then repeat. if unsuccessful, consider chest drain, once decompressed will need a chest drain to continue decompression
- if not haemodynamically unstable: chest drain
- admit to ICU if appropriate, admit to hospital
- treat underlying cause
How do you treat a tension pneumothorax?
- if suspected, attempt to aspirate before CXR. Use a large bore cannula and, if possible with syringe, filled with saline, to act as water seal, when entering the pleural space.
- attempt decompression at the 2nd intercostal space mid-clavicular line
- use a long needle
- should go just above third rib to avoid neurovascular bundle
- chest tube should be placed as soon as possible
- if pneumothorax remains at 48 hours or patient has recurrent episodes then consider pleurodesis
