ODCs in a theoretical healthy subject with a normal blood haemoglobin (Hb) concentration of 15 g ⋅ dL−1. The y-axis can be plotted as either % saturation or oxygen content (concentration); with the latter showing the very small amount of oxygen dissolved in solution.
ODCs in a theoretical subject with anaemia and haemoglobin (Hb) concentration of 7.5 g ⋅ dL−1 compared to normal haemoglobin concentration of 15 g ⋅ dL−1. When oxygen content is plotted against PO2 the curve in anaemia is scaled down by 50%, reflecting the halving of oxygen carrying capacity (dissolved oxygen is ignored); when SaO2 is plotted the anaemic and normal curves are superimposed.
Comparison of average oxygen dissociation curves based on measured arterial blood saturation and arterial PO2 in patients with normal pH (7.35–7.45) with values calculated using the simplified Severinghaus equation.