Examples
Consider a person who has a PaO2 of 10 kPa with a [Hb] of 150 g/L which is 97% saturated with oxygen. What will the oxygen content per litre of arterial blood be in this person?
It will be equal to:
(150 x 1.34 x 97%) + (0.23 x 10)
= 195 + 2.3
≈ 197 ml
Now consider if the inspired oxygen is increased such that the PaO2 is 50 kPa. This will result in the Hb being 100% saturated. What will the oxygen content be in this case?
It will be:
(150 x 1.34 x 100%) + (0.23 x 50)
= 201 + 11.5
= 212.5 ml/L blood
Now consider if the inspired oxygen is reduced to 4.5 kPa, resulting in the haemoglobin being 57% saturated. What will the oxygen content per litre of blood be in this case?
It will be:
(150 x 1.34 x 57%) + (0.23 x 4.5)
= 115 + 1.03
= 116 ml/L blood