Measured Versus Calculated Saturation - Nellcor OxiMax N-600X Operator's Manual

Principles of Operation

Measured versus Calculated Saturation

174
When saturation is calculated from a blood gas partial pressure of
oxygen (PO ), the calculated value may differ from the SpO
2
measurement of a pulse oximeter. This usually occurs because the
calculated saturation was not properly corrected for the effects of
variables that shift the relationship between PO
the partial pressure of carbon dioxide (PCO
hemoglobin. See Figure 12.
Figure 12: Oxyhemoglobin Dissociation Curve
2
and pH, temperature,
2
), 2,3-DPG, and fetal
2
N-600x Operator's Manual