Respiratory Failure

Question 1

What is type 1 respiratory failure?

Answer 1

When theres low O2 but normal CO2

PaO2 < 8kPa
PaCO2 = normal

Question 2

What is type 2 respiratory failure?

Answer 2

When there is low oxygen and high carbon dioxide

PaO2 < 8kPa
PaCO2 > 6kPa

Question 3

What is the cause of type 1 respiratory failure?

Answer 3

A ventilation-perfusion mismatch - when theres not enough air in comparison to the blood.

Question 4

What are causes of type 1 respiratory failure?

Answer 4

Asthma
Pulmonary embolism 
Pneumonia
Pneumothorax
Congestive cardiac failure

Question 5

What is Low ventilation-perfusion (V/Q)?

Answer 5

When theres not enough air getting into the lungs to perfuse all of the blood. The blood getting to the lungs is fine.

Eg - bronchoconstriction in asthma

Question 6

What is a high ventilation-perfusion (V/Q)?

Answer 6

When there is enough air getting into the lungs but theres not enough blood.

Eg - Pulmonary embolism.

Question 7

What is the cause of type 1 respiratory failure?

Answer 7

A V/Q mismatch. Can be a high V/Q or a low V/Q

Question 8

What is the cause of type 2 respiratory failure?

Answer 8

Alveolar hypoventilation - the lungs can’t exchange the oxygen and carbon dioxide properly

Question 9

What are the causes of type 2 respiratory failure?

Answer 9

COPD
Opiates - depression of the respiratory centre
Restrictive lung disease
Rib fracture
Neurological problems - Guillan barre syndrome, motor neurone disease.