Resp physiology

Question 1

Six causes of hypoxaemia

Answer 1

Reduced PiO2
Hypoventilation
V/Q mismatch
Diffusion limitation
Shunting
Reduced mixed venous oxygenation

Question 2

3 Mechanisms for compensating for gas hypoxaemia

Answer 2

Increase O2 extraction
Increase CO
Increase ventilation

Question 3

4 causes of diffusion limitation

Answer 3

Alveolar-capillary block (diffuse lung disease)
Loss of diffusing surface (emphysema)
Capillary volume (pulmonary hypertension)
Hb (anaemia)

Question 4

How can a diffusion limitation be measured

Answer 4

Using the DLCO (diffusing capacity lung CO).