Respiratory failure

Question 1

What is type 1 respiratory failure?

Answer 1

PaO2 <8 kPa, PaCO2 normal

Question 2

What is the cause of type 1 respiratory failure?

Answer 2

ventilation-perfusion (V/Q) mismatch; the volume of air passing in and out of the lungs is comparatively smaller than the volume of blood perfusing the lungs (or can be the other way around)

Question 3

What are 5 examples of causes of Type 1 respiratory failure?

Answer 3

1. Asthma
2. Congestive cardiac failure
3. Pulmonary embolism
4. Pneumonia
5. Pneumothorax

Question 4

What are 3 specific examples of a low V/Q?

Answer 4

= poor ventilation with oxygen but well-perfused by blood

1. Bronchoconstrition (asthma)
2. Airway collapse in emphysema
3. Mucus plug

Question 5

What is 1 specific example of a high V/Q?

Answer 5

= areas of lung with adequate ventilation but lacking blood perfusion e.g. pulmonary embolism

Question 6

What is the definition of type 2 respiratory failure?

Answer 6

PaO2 < 8kPa, PaCO2 > 6 kPa

Question 7

What is the aetiology of type 2 respiratory failure?

Answer 7

due to alveolar hypoventilation - the lugns fail to effectively oxygenate and blow off carbon dioxide

Question 8

What are 6 examples of causes of type 2 respiratory failure?

Answer 8

1. COPD (obstructive lung disease)
2. Idiopathic pulmonary fibrosis (restrictive lung disease)
3. Opiates - depression of respiratory centre
4. Guillain-Barre syndrome
5. Motor neuron disease
6. Rib fracture