Pneumothorax

Question 1

Define Pneumothorax

Answer 1

Air enters and accumulates in the pleural space
Primary: without clinically apparent pulmonary disease
Secondary: occurs as a complication of an underlying pulmonary disease e.g. COPD, asthma, thoracic endometriosis

Question 2

Aetiology of Pneumothorax

Answer 2

Often spontaneous due to sub-pleural bulla
Alveolar pressure > intrapleural pressure so any communication between alveolus and pleural space means gas will follow the pressure gradient

Caused by:
Trauma
Iatrogenic (subclavian CVP line insertion, pleural aspiration/biopsy, transbronchial biopsy, liver biopsy)

Question 3

What is a tension pneumothorax

Answer 3

Medical emergency that occurs when intrapleural pressure exceeds that of atmospheric pressure (especially in expiration)

The build up of pressure results in hypothermia and respiratory failure due to lung compression

Question 4

Risk factors for Pneumothorax

Answer 4

Smoking
Male 
Tall and slender
Family history 
Primary: young <40
Secondary: >55
Recent invasive medical procedure or chest trauma 
Acute severe asthma or COPD
TB 
Cystic fibrosis 
Carcinoma 
Sarcoidosis
Marfan’s, Ehler’s Danilo’s

Question 5

Symptoms of Pneumothorax

Answer 5

Asymptomatic

OR

Sudden onset:
Dyspnoea
Pleuritic chest pain

Question 6

Signs of Pneumothorax

Answer 6

Ipsilateral:
Reduced breath sounds 
Hyperinflation of the hemithorax -> reduced epxansion
Hyper-resonance on percussion
Hypoxia 

Tension: tracheal deviation away

Question 7

Investigations for Pneumothorax

Answer 7

CXR: area devoid of obvious lung markings, visible rim between lung margin and chest wall

Clotting studies and INR: before chest drain insertion
ABG: (If sats <92 on air) -> resp. Alkalosis, acute respiratory acidosis

USS: absence of lung sliding, “A line sign”, “Lung point”, “Barcode sign”
CT: visible pleural line, atelectasis of the lung or hyper-expansion of ipsilateral hemithorax, signs of underlying lung disease

Do NOT delay tension pneumothorax treatment

Question 8

Management of primary Pneumothorax

Answer 8

SOB and/or rim of air >2cm on CXR:
Needle aspiration using 16-18G cannula
Repeat CXR to see if rim is <2cm
If not -> chest drain insertion

Air <2cm on CXR
Discharge + OPD review

Question 9

Management of secondary Pneumothorax

Answer 9

SOB and/or rim of air >2cm on CXR
Chest drain insertion

Rim of air 1-2cm on CXR

1. Aspirate <2.5L using 16-18G cannula
2. Repeat CXR
3. Rim >1cm -> chest drain insertion + oxygen + admit
4. Rim <1cm -> high flow oxygen and admit

Question 10

What are the considerations for surgery for patients with Pneumothorax

Answer 10

Bilateral Pneumothorax
Lung fails to expand within 48hours of drain
Persistent air leak
2 or more previous events on the same side
History on the other side

Question 11

Management for tension Pneumothorax

Answer 11

Call cardiac arrest team
Insert large bore (14-16G) needle with a syringe partially filled with 0.99% saline into the 2nd ICS in the MCL on the suspected side
Remove the plunger to allow trapped air to bubble through the syringe until a chest drain can be placed

OR

Insert large bore Venflon in the same location

Question 12

Complications of Pneumothorax

Answer 12

Re-expansion pulmonary oedema
Talc pleurodesis-related ARDS

Tension: great vein compression -> cardiorespiratory arrest

Question 13

Prognosis for Pneumothorax

Answer 13

Primary: higher risk of recurrence (30-50% ipsilateral), higher risk of contralateral primary spontaneous pneumothorax

Secondary: greater risk of recurrence, typically secondary spontaneous pneumothoraces