Week 7: Respiratory tests, hx, ex

Question 1

What FEV1/VC ratio is considered obstructive/ restrictive

Answer 1

Obstructive: FEV1/VC <70%

Restrictive: FEV1/VC normal

Question 2

How would an OBSTRUCTIVE lung disease affect total lung capacity and residual volume

Answer 2

TLC ++ (due to hyperinflation)

RV ++ (due to gas trapping)

Question 3

How would a RESTRICTIVE lung disease affect total lung capacity and residual volume

Answer 3

TLC decreased

RV decreased/same

Question 4

What are pulmonary causes of an OBSTRUCTIVE respiratory disease pattern

Answer 4

• COPD
• Asthma (may have normal spirometry)
• Bronchiectasis

Question 5

What are pulmonary causes of a RESTRICTIVE respiratory disease pattern

Answer 5

Pulmonary fibrosis

Question 6

What are non-pulmonary causes of a RESTRICTIVE respiratory disease pattern

Answer 6

• Neuromuscular disorders
• Thoracic cage abnormalities
• Obesity

Question 7

Asthma is reversible with bronchodilators. What FEV1 change is considered reversed

Answer 7

FEV1 increased by >12% and by >200ml

Question 8

What does TLCO measure

Answer 8

TLCO = transfer factor

Tests function of alveolar capillary membrane (V and Q)

Question 9

What does KCO measure

Answer 9

KCO = transfer coefficient

Measures function per unit volume of lung

Question 10

How are TLCO and KCO affected in asthma

Answer 10

Both normal

Question 11

How are TLCO and KCO affected in COPD

Answer 11

Both reduced

Question 12

How are TLCO and KCO affected in idiopathic pulmonary fibrosis

Answer 12

Both reduced

Question 13

How are TLCO and KCO affected in extra-pulmonary causes of reduced lung function (eg thoracic cage abnormalities, obesity)

Answer 13

TLCO reduced

KCO increased/ normal

Question 14

How are TLCO and KCO affected in pulmonary hypertension

Answer 14

Both reduced

Question 15

Which type of CT is better for seeing a diffuse lung condition eg fibrosis

• High-res CT
• Spiral/ helical CT

Answer 15

High-res CT

Question 16

Which type of CT is better for finding small nodules

• High-res CT
• Spiral/ helical CT

Answer 16

Spiral/ helical CT

Question 17

5 Lung diseases that exposure to silica can cause

Answer 17

1. Silicosis (lung fibrosis)
2. Acute silicosis
3. COPD
4. TB
5. Lung cancer

Question 18

Components of light’s criteria for pleural effusion

Answer 18

1. Protein >30g/L
2. Lactate dehydrogenase >2/3
3. Leukocytes

Question 19

People at risk of T2 respiratory failure

Answer 19

1. COPD
2. Obesity
3. Neuromuscular disorders
4. Skeletal abnormalities

Question 20

In which lung conditions might a broncho-alveolar lavage be useful? What are their respective findings

Answer 20

1. Hypersensitivity pneumonitis: mast cells, lymphocytes

2. Sarcoidosis: neutrophils, lymphocytes

Question 21

Contraindications for NIV

Answer 21

1. Reduced GCS
2. Facial/ upper airway trauma
3. Pneumothorax + no chest drain
4. Inability to protect airway (eg nerve paralysis)

Cardiogenic pulmonary oedema and chest wall deformities are NOT contraindications

Question 22

How might someone with a diaphragmatic palsy present

Answer 22

Orthopnoea