Pneumothorax

Question 1

What are the causes of a pneumothorax?

Answer 1

1. Primary
2. Secondary (respiratory disease, connective tissue disease, lung cysts, iatrogenic, trauma, )

1. Primary pneumothorax

2. Secondary pneumothorax
A. Respiratory: COPD, asthma, CF, ILD, PTB, malignancy, pneumonia, lung abscess, pneumoconiosis, sarcoidosis

B. CTD: Marfan, Ehlers-Danlos, pseudoxanthoma elasticum

C. Lung cysts: lymphangioleiomyomatosis, Langerhans cell histiocytosis X, tuberous sclerosis, neurofibromatosis

D. Iatrogenic: pleural aspiration/biopsy, thoracocentesis, central venous access, pacemaker insertion, CPR

E. Trauma

Question 2

What are the BTS guidelines on the management of a spontaneous primary pneumothorax?
What is teh rate of resolution of spontaneous primary PTX?

Answer 2

Minimal symptoms and air rim of <2cm can be allowed home with repeat CXR in 7 days

Slow resorption rate 1.22 - 1.8% of volume of hemithorax every 24 hours

Question 3

How would you manage a secondary pneumothorax?

Answer 3

1. Observation alone (<1cm or isolated apical pneumothorax in an asymptomatic patient)
2. Aspiration if <50 years, asymptomatic or small <2cm, then observe 24H
3. Chest drain if >50 years, symptomatic or large >2cm

Question 4

Case presentation of pneumothorax

Answer 4

Large untreated pneumothorax unlikely to present in examination

Usually ongoing treatment with chest drain
1. Reduced chest expansion over side of pneumothorax
2. Percussion hyper-resonant
3. Reduced vocal fremitus
4. Reduced breath sound

Mention negative severe signs of tension/large PTX:
5. No raised venous pressure
6. No/mild trachea deviation to opposite side
7. No displaced apex beat to pposite side
8. Previous drain scars - recurrent pneumothorax

Look for secondary causes of pneumothorax:
9. Finger clubbing, creps- bronchiectasis, CF, malignancy, ILD
10. Tar staining, prolonged expiration, wheeze - COPD
11. Reduced cricoid-notch distance (hyperinflation)
12. Iatrogenic - pleural biopsy/aspiration, PPM insertion, central venous access

Question 5

What are the clinical signs of tension pneumothorax?

Answer 5

1. Tracheal deviation to opposite side
2. Mediastinal shift, apex beat displaced to opposite side
3. Raised venous pressure

Question 6

PA CXR appears normal, but you still suspect pneumothorax, what should you do?

Answer 6

Lateral and decubitus chest x-ray

Question 7

Do you think there is a role of CT thorax in diagnosing pneumothorax?

Answer 7

CT thorax able to:
1. Differentiate pneumothorax from complex bullous disease
2. Evaluate when CXR is obscured by surgical emphysema

Question 8

Size of tube for intercostal drainage

Answer 8

Small tubes (10-14F) are similar to large tubes (20-24F)
Small tube may have risk of persistent air leak, requiring exchange with larger tube.

Question 9

When should you apply chest drain suction?

Answer 9

After 48 hours for persistent air leak or failure of pneumothorax to expand

High volume, low pressure system (10-20cm H2O)

Question 10

Management of tension pneumothorax

Answer 10

1. High flow oxygen
2. Large bore cannula into second intercostal space mid-axillary line on affected side
3. Insert intercostal drain

Question 11

Re-expansion pulmonary oedema

Answer 11

Prolonged duration of lung collapse
Esp in patients who do not seek medical advice for several days
(46% patients with symptoms wait for 2 days before visit)

Question 12

Describe the pathophysiology of primary spontaneous PTX

Answer 12

1. Rupture of apixal pleural blebs under visceral pleura
2. Usually in tall individuals without underlying respiratory disease
3. 90% are smokers - 20-fold in males, 10-fold in females