Pneumothorax

Question 1

What is it

Answer 1

Collection of air in the pleural cavity leading to collapse of the lung

Question 2

Types

Answer 2

Primary Spontaneous (PSP) - spontaneous, occuring in younger people
Secondary - associated with underlying lung disease
Tension pneumothorax - Medical Emergency requiring immediate treatment

Question 3

Clinical presentation

Answer 3

Sudden onset of pain
Shortness of breath
Severe respiratory distress in tension pneuothorax

Question 4

Aetiology of Primary Spontaneous

Answer 4

Idiopathic/rupture of pleural bleb

Usually found in young, tall, slim men

Question 5

Aetiology of Secondary

Answer 5

In patients with prior lung disease e.g. COPD, sarcoidosis or idiopathic pulmonary fibrosis

Question 6

Pathophysiology of PSP or Secondary

Answer 6

Pocket of air in pleural cavity leads to partial or complete collapse of the lung on affected side

Question 7

Aetiology of tension pneumothorax

Answer 7

Rare
Can be iatrogenic from mechanical ventilation/chest drains
Generally due to blunt, traumatic injuries e.g. stab wound

Question 8

Pathophysiology of tension pneumothorax

Answer 8

Pleural tear acts as a one-way valve.
Allows air into the cavity but not out.
This leads to mediastinal shift and lung collapse (mediastinum is pushed over into contralateral hemithorax, kinking and compressing the great veins).
Increasing unilateral pressure -> Severe respiratory distress, shock and cardiorespiratory arrest. (if air is not rapidly removed)

Question 9

Epidemiology of PSP

Answer 9

Males = 24/100,000
Females = 10/100,000
Smokers have increased risk
Most often occurs in 20s

Question 10

Diagnosis of PSP or secondary

Answer 10

CXR (not if tension pneumothrax is suspected)

Question 11

Treatment

Answer 11

Aspiration and oxygen.
Stop smoking to prevent recurrence.
Pleurodesis.

Question 12

Causes

Answer 12

Rupture of subpleural bulla (spontaneous)
Chronic lung disease (astham, COPD, CF, lung fibrosis)
Sarcoidosis
Infection (TB, pneumonia, lung abscess)
Idiopathic pulmonary fibrosis
Rheumatoid arthritis
Ankylosing spondylitis
Traumatic (including iatrogenic)
Lung Carcinoma
Connective tissue disorders (Marfan’s syndrome, Ehlers-Danlos syndrome)

Question 13

Iatrogenic causes of trauma leading to pneumothorax

Answer 13

CVP line insetion
Pleural aspiration or biopsy
Percutaneous liver biopsy
Positive pressure ventilation

Question 14

Symptoms

Answer 14

Asymptomatic possible (especially fit young) or sudden onset of dyspnoea and/or pleuritic chest pain
Asthma or COPD patients may present rapid deterioration
Hypoxia in mechanically ventilated patients

Question 15

Signs

Answer 15

Reduced expansion
Hyper-resonance to percussion
Diminished breath sounds on affected side

Question 16

Signs of tension pneumothorax

Answer 16

Respiratory distress
Tachycardia
Hypotension
Distended neck veins
Trachea deviated away from side of pneumothorax
Increased percussion note
Reduced air entry/breath sounds on affected side

Question 17

Tests

Answer 17

ABG - hypoxia
CT scan
CXR (not tension as no time) - pleural line; may show tracheal deviation away from lesion
Expiratory film and look for an area devoid of lung markings, peripheral to edge of collapsed lung

Question 18

Primary pneumothorax management

Answer 18

SOB and/or rim of air >2cm on CXR
If no: Consider discharge and outpatient review in 2-4 wks*
If yes: Aspiration
If successful *
If not successful then chest drain

Question 19

Secondary pneumothorax management

Answer 19

SOB or rim of air >2cm on CXR?
If yes = chest drain*
If no: Is the size 1-2cm?
If no = admit for 24 hours observation and put on O2
If yes = aspiration:
If successful = admit for 24 hours observation and put on O2
If not successful = *

Question 20

Treatment of tension pneumothorax

Answer 20

Requires immediate decompression with a large bore needle inserted into the 2nd intercostal space mid-clavicular line.

Remove air insert large-bore needle with syringe partly filled with saline into suspected side of pneumothorax.
(Remove plunger to allow trapped air to bubble through syringe until chest tube can be placed)
Then request CXR
Then insert chest drain

Question 21

Treatment of pneumothorax due to trauma or mechanical ventilation

Answer 21

Chest drain

Question 22

Complications of pneumothorax

Answer 22

Risk of future pneumothorax
Respiratory failure
Cardiac arrest