resp diseases investigations

Question 1

COPD

Answer 1

spirometry

obstructive = low, low, low

Question 2

Asthma

Answer 2

spirometry

obstructive = normal, low, low

Question 3

pneumonia

Answer 3

blood culture
ABG
CXR
CURB65

Question 4

cystic fibrosis

Answer 4

• Sweat test - diagnostic
• Genetic testing for CFTR mutations

Question 5

bronchiectasis

Answer 5

High-resolution CT (HRCT is main test) - thickened and dilated airways, ‘tram-line shadowing’

Antiobody test - IgG,M,A

Question 6

pneumothorax

Answer 6

• CXR - Useful to differentiate bullous lung disease or small pneumothoraces
  
  • Small ≤2cm rim of air
  • Large ≥2cm rim of air

Question 7

pleural effusion

Answer 7

CXR
- >500ml will cause a clear fluid level

Question 8

lung cancer

Answer 8

Bronchoscopy and biopsy of tumour if seen
CXR within 2 weeks

Bloods
- FBC
- Coagulation screen
- ↓ Na+, ↑Ca2+ indicates malignancy

Question 9

sarcoidosis

Answer 9

• Bloods - elevated serum ACE level, raised CRP, hypercalcaemia
• CXR may show bilateral hilar or paratracheal lymphadenopathy

Question 10

obstructive sleep apnoea

Answer 10

Overnight sleep study - oximetry, domiciliary reading, full polysomnography (gold standard)

Question 11

pulmonary embolism

Answer 11

wells score
D dimer
CT Pulmonary Angiogram (CTPA) - MAIN TEST
V/Q

Question 12

pulmonary hypertension

Answer 12

• ECHO doppler - estimates systolic pulmonary arterial pressure
• Right heart catheterization to confirm
• Others: ECG (right axis deviation, RBBB), CXR (cardiomegaly)

Question 13

TB

Answer 13

PCR

CXR
- Shadows, lesions, consolidation
- Ghon focus in periphery of mid zone of lung - primary site of infection
- Bilateral hilar lymphadenopathy
- ‘Miliary shadowing’ = miliary TB