Pneumothorax

Question 1

what is the pleural cavity

Answer 1

the potential space between the visceral and parietal pleural

Question 2

what is pneumothorax

Answer 2

the presence/ accumulation of air or gas in the pleural cavity which can impair oxygenation and ventilation

Question 3

etiological classification of pneumothorax

Answer 3

1st spontaneous
2nd spontaneous
traumatic
iatrogenic

Question 4

1st spontaneous

Answer 4

• no underlying lung pathology evident
  *more common in tall men aged 20- 4- years who smoke
  *probably due to rupture of apical subpleural blebs/ bullae

Question 5

2nd spontaneous

Answer 5

*pleural rupture due to underlying disease: emphysema, cystic fibrosis etc.
* infection through cavitating pneumonia e.g. Staphylococcus/ TB/ abscess

Question 6

traumatic

Answer 6

penetrating/ blunt

Question 7

iatrogenic

Answer 7

after pleural biopsy or aspiration, transbronchial biopsy, percutaneous lung biopsy, subclavian vein central line insertion, mechanical ventilation with high airway pressures

Question 8

clinical presentation of pneumothorax

Answer 8

depends on the type of pneumothorax, and can be asymptomatic to potentially life- threatening

Question 9

history on a patient with pneumothorax

Answer 9

patient can present with sudden onset SOB and/or chest pain

Question 10

hallmarks physical exam findings on a patient with pneumothorax

Answer 10

decreased air entry on the affected side
hyper-resonance with percussion

Question 11

investigations: CXR

Answer 11

look for hyperlucency of one lung field. be careful in COPD patients, it may bullous
small= visible rim <2cm measured a hilum

large=visible rim> 2cm measured at hilum

Question 12

what does the management of a pneumothorax depend on

Answer 12

*spontaneous or not
*if spontaneous, is it primary or secondary
*symptomatic or not
*size of pneumothorax

Question 13

management options

Answer 13

observation
aspiration
placement of an intercostal drain

Question 14

indication for ICD placement

Answer 14

a. tension pneumothorax
b. primary pneumothorax with failed aspiration
c. secondary pneumothoraces in symptomatic patient> 50 yrs
d. associated blood/water/ pus
e. mechanically ventilated patients with pneumothorax
f. for interhospital transfer if a pneumothorax is present
g. traumatic pneumothorax
h. bilateral pneumothoraces

Question 15

indication for aspiration

Answer 15

a. primary pneumothoraces not suitable for observation and no indication for ICD placement
b. small secondary pneumothoraces in minimally SOB patients <50 yrs of age

Question 16

needle aspiration techniques

Answer 16

• patient must be admitted for 24 hrs on high flow O2
• it should be done under local anesthetic, until resistance is felt or patient coughs excessively
  *it can be repeated
  *repeat CXR 6hrs later

Question 17

indications for in patient observation

Answer 17

All patient that do not meet criteria for needle aspiration or ICD placement need to be admitted for monitoring for 6 hours. This is done if the pneumothorax is small and the patient is not symptomatic. The patient is observed for 6 hours while placed on oxygen. A repeat CXR is done 6 hours later. If no expansion and patient has no symptoms and they are able to return to the hospital, they can be discharged.

Question 18

use of face mask oxygen

Answer 18

· O2 accelerates the reabsorption of pneumothoraces up to 4 fold.

· Most of the pneumothorax is nitrogen (N2).

· O2 ↓ the partial pressure of N2 in the blood, thus ↑ the gradient for its reabsorption.

Question 19

what is tension pneumothorax

Answer 19

Tension pneumothorax is the progressive build-up of air within the pleural space due to a ‘one-way-valve’ effect.

• Progressive build-up of pressure in the pleural space pushes the mediastinum to the opposite hemithorax and obstructs venous return to the heart.
• This leads to cardiovascular instability and will eventually lead to cardiac arrest if not treated promptly.

Question 20

neuro clinical features of tension pneumothorax

Answer 20

Confusion, restlessness

Question 21

resp clinical features of tension pneumothorax

Answer 21

• Extreme tachypnoea + hypoxia +/- cyanosis
• Uneven chest rise
• Tracheal shift to the opposite side
• Affected side hyperresonant with ↓ air entry

Question 22

cvs clinical features of tension pneumothorax

Answer 22

• Diaphoresis, ↑JVP, tachycardia, Hypotension, Shock

        (↑ intrathoracic pressure → ↓ venous return to the heart → ↓ cardiac output)

Question 23

management of tension pneumothorax

Answer 23

• DON’T WAIT !!
• O2
• NEEDLE THORACOSTOMY
• Insert the largest available IV cannula perpendicular to the chest wall in the 2nd ICS mid-clavicular line on the side of the pneumothorax. Air should rush out..

Intercostal drain as soon as possible