Pneumothorax

Question 1

what is a pneumothorax

Answer 1

air in the pleural space

Question 2

how is pressure in the pleural space established

Answer 2

Muscle tension of the diaphragm & chest wall – contract and expand thoracic cavity outward
Elastic recoil of the lungs – pull lungs inward
2 forces pull on each other creating a balance
Creates a slight vacuum = -5cm of water

Question 3

what is the mechanism of a pneumothorax?

Answer 3

Pneumothorax forms when seal of pleural space is punctured = air moves in = pressure in pleural space = 0cm of water
Since negative pleural pressure is lost, the opposing forces do not pull on each other = lungs pull in = COLLAPSE

Question 4

what is the consequence of lung collapse?

Answer 4

↓ oxygen

↑ carbon dioxide (can’t get released)

Question 5

what are the 3 types of pneumothorax?

Answer 5

spontaneous
traumatic
tension

Question 6

what is the mechanism of a spontaneous pneumothorax

Answer 6

Bullae (large air pocket) forms on lung surface and breaks
Form when alveoli develops a small leak
Normally alveoli heal up, but result is a bullae
When breaks creates a hole in visceral pleura
Air goes from airway directly to pleural space

Question 7

what are the 2 types of spontaneous pneumothorax

Answer 7

primary - absence of underlying condition

secondary - underlying lung disease

Question 8

what are the risk factors for a primary spontaneous pneumothorax?

Answer 8

smoking, family history, marfan syndrome, homocystinurea, tall young men in 20s

Question 9

what are the causes for a secondary spontaneous pneumothorax

Answer 9

marfans, CF, emphysema, lung cancer, COPD, pneumonia, TB

Question 10

what is the mechanism of a traumatic pneumothorax

Answer 10

Trauma rips through parietal pleura

Air can enter from outside directly into pleural space

Question 11

causes of a traumatic pneumothorax

Answer 11

gunshot or stab wound

Question 12

mechanism of a tension pneumothorax

Answer 12

Creates a one way valve
Air can enter but cannot leave as flap of tissue doesn’t allow tissue to go the other way
Air can build up, increasing pressure

Question 13

causes of a tension pneumothorax

Answer 13

similar to spontaneous or traumatic pneumothoraxes

Question 14

what are the symptoms of a pneumothorax?

Answer 14

SOB, pleuritic chest pain, symptoms develop at rest, reduced breath sounds on affected sounds, hyperresonance, hypoxia

Question 15

what will the features of a simple pneumothorax be on a CXR

Answer 15

trachea is not deviated. Lung collapse may be visible

Question 16

what will the features of a tension pneumothorax be on xray

Answer 16

the trachea may be deviated away from the side of the pneumothorax. Lung collapse likely to be more obvious

Question 17

what additional symptoms will tension pneumothoraxes have?

Answer 17

tracheal deviation

Haemodynamically unstable - Hypotensive, Tachycardic, Elevated respiratory rate

Question 18

what investigations can be done for pneumothoraxes?

Answer 18

Xray - lung tissue mostly black, air in pleural space is entirely black
CT - not routinely indicated
US - absence of lung sliding
Blood gas - hypoxia, resp alkalosis

Question 19

what are the complications associated with pneumothoraxes?

Answer 19

compression of mediastinum can lead to increased HR, raised JVP, cardiac arrest

Question 20

how to treat a standard pneumothorax rim of air<2cm

Answer 20

Consider observation for 4-6 hours and repeat CXR to ensure it is not progressing
Then; discharge on advice – don’t do strenuous exercise – and return if breathless.
Evaluate and re-x-ray at 2 weekly intervals until air is re-absorbed

Question 21

how to treat a • Primary Pneumothorax - SOB + rim of air >2cm on CXR

Answer 21

If acutely unwell
Aspiration – 2nd intercostal space, mid clavicular line
If unsuccessful repeat
if unsuccessful again consider chest drain
If not haemodynamically unstable = Chest drain

Question 22

how to treat a Secondary Pneumothorax – SOB + rim of air >2cm on CXR

Answer 22

same as primary pneumothorax, treat underlying cause

Question 23

how to treat an tension pneumothorax

Answer 23

If suspected aspirate before CXR
Use a large bore cannula with a long needed and, if possible with syringe, filled with saline, to act as a water seal, when entering the pleural space.
You should attempt decompression at the 2nd intercostal space at the mid-clavicular line.
Chest tube placed as soon as possible
If remains at 48 hours or recurrent consider pleurodesis