 ### Description

Several formulas are available for adjusting a blood gas pO2 determined at 37 °C for a patient's body temperature. For elevated body temperatures, the pO2 is increased, while for decreased body temperatures it is decreased. The equations tend to be complex because of the shifts in the hemoglobin-oxygen dissociation curve caused by changes in temperature and pH.

The formula for the Radiometer ABL-3 is:

corrected pO2 =

= (measured pO2) * (10 ^ ((((0.0252) / ((0.243 * (((measured oxygen) / 100) ^3.88))+1))+0.00564) * ((patient temperature in °C) -37)))

The formula for the Corning blood gas instruments is:

corrected pO2 =

= (measured pO2) * (10^ ((0.0052+((0.027) * (1-(10^((-0.13) * (100 - (oxygen saturation))))))) * ((patient temperature in °C) -37)))

The formula for the Instrumentation Laboratory (IL) models 1301 and 1303 is:

corrected pO2 =

= (measured pO2) * (10^((((5.49*(10^(-11)) * ((measured oxygen) ^ (3.88))) +0.071) / ((9.72 * (10^(-9)) * (measured oxygen) ^3.88))+2.3)) * ((patient temperature in °C) - 37)))

The formula for the IL model 813 if oxygen saturation <= 95%:

corrected pO2 =

= (measured pO2) * (10^ (0.031 * ((patient temperature in °C) -37))))

The formula for the IL model 813 if oxygen saturation > 95%:

corrected pO2 =

= (measured pO2) * (10^((0.032-(0.0268 * (EXP((0.3 * (oxygen saturation))-30)))) * ((patient temperature in °C) -37)))))

A formula proposed by Siggaard-Andersen et al is:

corrected pO2 =

= (measured pO2) * (EXP((((0.012 * ((measured pO2) / 714)) + (((oxygen saturation) / 100) * (1 - ((oxygen saturation) / 100)) * ((hemoglobin in g/dL) / 0.6) * 0.073)) / (((measured pO2) / 714) + (((oxygen saturation)/100) * (1 - ((oxygen saturation) / 100)) * ((hemoglobin in g/dL) / 0.6)))) * ((patient temperature in °C)-37)))