[cardiacRN2006]

Sheesh! I never did like that darn curve...

[JenSICU_CCRN]

Originally Posted by heartICU

Actually, it is just the opposite. On the oxyhemoglobin disassociation curve, the curve shifts to the right with an increase in temperature, and that is a decreased affinity of the hemoglobin for oxygen. The saturation measures what percentage of Hgb is fully saturated. If you have a decreased affinity for oxygen, more oxygen will unload to the tissues, therefore decreasing the amount that is carried by the hemoglobin, so your pulse ox will read lower. Things that decrease hemoglobin affinity for oxygen include fever, acidosis/increased c02, decreased pH, sickle cell anemia, maternal hemoglobin, etc.

When the patient is cold, your tissues need less oxygen, so the hemoglobin has a higher affinity for oxygen, so the curve shifts to the left. Other things that shift to the left (and increase affinity) include decreased temp, increased pH, decreased Pco2, fetal hemoglobin, carboxyhemoglobin, and methemoglobin.

Make sense?

Sorry, I had my right and left confused-LOL....I do that commonly with everything right and left. I also had been up for almost 30 hours when I posted. Sorry again.

Jen

[christymwinn]

Very intersting! That was a good explanation, and even though I didn't ask the original question, thanks!

[Toronto]

Originally Posted by heartICU

Actually, it is just the opposite. On the oxyhemoglobin disassociation curve, the curve shifts to the right with an increase in temperature, and that is a decreased affinity of the hemoglobin for oxygen. The saturation measures what percentage of Hgb is fully saturated. If you have a decreased affinity for oxygen, more oxygen will unload to the tissues, therefore decreasing the amount that is carried by the hemoglobin, so your pulse ox will read lower. Things that decrease hemoglobin affinity for oxygen include fever, acidosis/increased c02, decreased pH, sickle cell anemia, maternal hemoglobin, etc.

When the patient is cold, your tissues need less oxygen, so the hemoglobin has a higher affinity for oxygen, so the curve shifts to the left. Other things that shift to the left (and increase affinity) include decreased temp, increased pH, decreased Pco2, fetal hemoglobin, carboxyhemoglobin, and methemoglobin.

Make sense?

Fever is an increase in temperature. An increase in temperature causes a shift to the RIGHT. An increase in temperature would cause hemoglobin to lose its affinity for Oxygen. The bond between hemoglobin and oxygen break more easily and oxygen is delivered to the tissues more efficiently. "at this point a lower SpO2 is acceptable in patients with these conditions because oxygen is being delivered to their tissues more efficiently."

[Toronto]

Originally Posted by cardiacRN2006

Sheesh! I never did like that darn curve...

Fever is an increase in temperature. An increase in temperature causes a shift to the RIGHT. An increase in temperature would cause hemoglobin to lose its affinity for Oxygen. The bond between hemoglobin and oxygen break more easily and oxygen is delivered to the tissues more efficiently. "at this point a lower SpO2 is acceptable in patients with these conditions because oxygen is being delivered to their tissues more efficiently."