PaO2: Temperature Correction

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excalibur

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I couldn't find a really good article explaining this, but from what I could gather it seems that...

Hyperthermia decreases the solubility of O2 in blood, and therefore increases the PaO2

Hypothermia increases the solubility of O2 in blood, and therefore decreases the PaO2

It appears that although these concepts are true, it is unnecessary to make corrections in the PaO2's of ABG's in hypo/hyperthermic pts.

Does this accurately sum up this keyword? Any additional info or links to good articles would be appreciated.
 

Freibi

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http://images.google.de/imgres?imgurl=http://upload.wikimedia.org/wikipedia/commons/8/8a/Oxyhaemoglobin_dissociation_curve.png&imgrefurl=http://reference.findtarget.com/search/oxygen-hemoglobin%2520dissociation%2520curve/&usg=__KVlPmcnA1O8Myhom-o7BjPPl2dg=&h=413&w=439&sz=40&hl=de&start=30&tbnid=rPVgeY-jIn1gUM:&tbnh=119&tbnw=127&prev=/images%3Fq%3Dhemoglobin%2Bbinding%2Bcurve%26start%3D20%26gbv%3D2%26ndsp%3D20%26hl%3Dde%26sa%3DN

Snow White's mother, the late good queen, lost a drop of capillary blood in the snow while doing her stitchwork, and it looked red (not purple) - this proves the enhanced binding of O2 to hemoglobin in cold temperatures ;)

So, does anyone know how much it matters within the range of possible body temperatures?
 

proman

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Faust page 22 Blood Gas Temperature Correction has a nice, short description. It's related to pH-stat or alpha-stat management of blood gases while hypothermic (on bypass). The pH and PaCO2 temp difference seems most important. Clinically I don't think the effect of temp on PaO2 is important (other than to know the concept).
 
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how why

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O2 dissolves into the blood easier when the temperature is low. That is, lower partial pressure is required to reach the same amount of O2 dissolved in the blood. But when we measure PaO2, we use an electrode and detect the current of the redox reaction generated by O2 diffusion from the sample. Then, the computer will calculate the amount of O2 required for generating the current based on a math formula. So, if the default setting of the computer is that the sample is obtained from a person with 37 degree Celsius, we would overestimated the partial pressure. (As mentioned above, lower partial pressure is required for the same amount of O2 in the blood.) So we need temperature correction when we interpreting the data. Basically, the real partial pressure would be higher in hyperthermia and lower in hypothermia.
 

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