Pneumothorax Flashcards
What is a pneumothorax
It is air in the pleural space
Why might a traumatic pneumothorax occur
Stabbing, rib piercing pleura in trauma
Difference between primary and secondary spontaneous pneumothorax
Primary spontaneous pneumothorax occurs in people without known respiratory illnesses
Secondary spontaneous pneumothorax occurs in patients with pre existing pulmonary diseases
How does primary spontaneous pneumothorax occur
It is thought to be due to small apical blebs or Bullae (ie, air sacs between the lung tissue and pleura) that rupture into the pleural cavity.
Classically occurs in tall, thin males between the ages of 10 and 30 years. (PSP is 3-6 times commoner in males than females)
The development of subpleural blebs is thought to be due to either increasing negative pressure or greater mechanical alveolar stretch at the apex of the lungs during growth.
Risk factors include smoking tobacco and cannabis
Recurrence is common
How does pneumothorax present
Usually an acute history
Can be asymptomatic (rare)
Sudden onset dyspnoea and pleuritic chest pain
Usually unilateral but may be bilateral
Examination may be normal in small pneumothoraces
What are the physical signs of pneumothorax
Inspection – tachypnoea, reduced movement on affected side.
Palpation – reduced expansion on affected side, crepitus if surgical
emphysema (leaked air into subcutaneous tissue). Tracheal shift if tension pneumothorax.
Percussion – hyper-resonate on affected side.
Auscultation – absent breath sounds / vocal resonance.
How to measure size of pneumothorax
Check the interpleural distance at hilum (edge of thorax to lung edge)
What does chest x-ray show for pneumothorax
Initial investigation of choice.
Visible lung edge (visceral pleural line – see arrow).
Absent lung markings
How does tension pneumothorax occur
If the opening allowing air into the pleural space acts as a one way valve then the air will build up and pressure increase leading to a Tension Pneumothorax. Air cannot exit so it compresses the lungs and shifts mediastinum, elevated intrathoracic pressure decreases cardiac filling and stroke volume. Ultimately heart wont be able to pump and you will have a cardiac arrest , and you will have pulseless electrical activity
Management of pneumothorax
Treatment of pneumothorax
Conservative (i.e. do nothing)
Pleural aspiration
Intercostal Drain (12-18Fr – Seldinger)
“surgical” drain (20-32Fr – blunt dissection)
Pleural Vent
What is the triangle of safety
3rd 4th 5th intercostal spaces
Why do use an underwater seal for chest drain
The chest drain is connected to an underwater seal to stop air re-entering the pleural cavity during inspiration.
When can pleural vents be used
In primary spontaneous pneumothorax when not severe so patient can be sent home
What is surgical emphysema
Air is leaked in subcutaneous tissue when there is a large leak of air, surgical drain is needed to remove air
What does pneumothorax look like on a cross sectional CT scan
