Pneumothorax

Question 1

What is a pneumothorax?

Answer 1

Presence/ accumulation air/gas in the pleural cavity (potential space between visceral + parietal pleura )
Impairs oxygenation + ventilation

Question 2

Describe the aetiology classification of pneumothoraces

Answer 2

1” spontaneous

• no underlying lung pathology
  -mostly d/t rupture apical subpleural blebs/ bullae
  -more common tall men (20-40 yrs) +smoke

2” spontaneous

• Pleural rupture d/t underlying disease: emphysema, cf
• infection through cavitation pneumonia eg. Staphylococcus, TB, abscess

Traumatic

• penetrating /blunt

Iatrogenic

• following pleural biopsy/aspiration, transbronchial biopsy, percutaneous lung biopsy, subclavian vein central line insertion, mech ventilation w high airway pressure

Question 3

Describe the clinical presentation of pneumothorax

Answer 3

• asymptomatic/potentially life threatening
  -hx = sudden onset SOB, chest pain
• o/e = decreased air entry affected side, hyper resonance (percussion)

Question 4

What are the investigations done for suspected pneumothoraces?

Answer 4

• CXR - hyperlucency 1 lung field (in copd pts may be bullous)
  Small= visible rim < 2 cm measured at hilum
  Large= visible rim> 2cm measured at hilum

Question 5

Describe the management of a pneumothorax

Answer 5

The management plan of a pneumothorax depends on

· Is the pneumothorax spontaneous or not?
· If it is spontaneous is it primary or secondary?
· Is the patient symptomatic, or not?
· What is the size of the pneumothorax.

Observation (no intervention) – which can either be in-hospital or as an outpatient with follow-up.
· Aspiration of the pneumothorax.
· Placement of an intercostal drain.

Question 6

Name the indications for ICD placement

Answer 6

• tension pneumothorax
• 1” pneumothorax w failed aspiration
• 2”pneumothorax in symptomatic pts > 50yrs
• associated blood/water / pus
• mechanically ventilated pts w pneumothoraces
  -inter hospital transfer if pneumothorax present
• traumatic pneumothorax
  -bilateral pneumothorax

Question 7

What are the indications for aspiration ?

Answer 7

• 1” pneumothoraces not suitable observation + no indications for ICD
  -small 2” pneumothoraces minimally SOB patients < 50yrs

-pt =admitted 24hrs on high flow O2
-done under local anaesthetic until resistance / pt coughs excessively
- can be repeated + repeat cxr 6hrs later

Question 8

What are the indications for observation?

Answer 8

• pts don’t meet criteria aspiration/ICD
• need to be admitted 6hrs + placed 02 + repeat cxr done after 6hrs if no expansion , pt = no sx , pt able to return to hospital can be discharged
• if pneumothorax small /not symptomatic

Question 9

Why are pts w pneumothoraces given O2 ?

Answer 9

· 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 10

What is a tension pneumothorax?

Answer 10

• progressive build-up of air w/in pleural space d/t one way valve effect
  = build up pressure in pleural space= pushes mediastinum to opp hemithorax + obstructs venous return of heart
  = cardiovascular instability = leading cardiac affect if not treated
  -dx =clinical +must be tx immediately

Question 11

What are the clinical features of a tension pneumothorax?

Answer 11

NEURO - Confusion, restlessness

RESP

• Extreme tachypnoea + hypoxia +/- cyanosis

• Uneven chest rise

• Tracheal shift to the opposite side

• Affected side hyperresonant with ↓ air entry

CVS

• Diaphoresis, ↑JVP,
tachycardia
Hypotension
Shock

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

Question 12

Describe the management of a tension pneumothorax

Answer 12

-O2
- needle thoracotomy - insert biggest available IV cannula perpendicular chest wall in 2nd ICS mid clavicular line on side pneumothorax and air should rush out
-ICD ASAP