cbrons

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Are elevated PaO2 readings normal in patients with CO poisoning? And why?

I would guess it is because conventional ABG doesn't distinguish between carboxy- and oxyhemoglobin but I'm sure I could be wrong about this.
 

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Mrr? Elevated PaO2? I could understand overestimated SpO2. Could be that I've forgotten everything, but this is the first I'm hearing of this.
 
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Apoplexy__

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Were you thinking that CO would kick off O2 so much that it would increase the pO2 or something? I've never read anything about this, and I'm sure it's not important.

I would guess it is because conventional ABG doesn't distinguish between carboxy- and oxyhemoglobin but I'm sure I could be wrong about this.
A bit confused what you mean here, as an ABG measuring carboxy- and oxyhemoglobin has nothing to do with pO2.
 

notbobtrustme

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nothing causes elevated PaO2 except hyperbaric oxygen.
 
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Only thing I can think of is that less hemoglobin bound-O2 means more O2 gas in the blood, thereby elevating PaO2.
 

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Are elevated PaO2 readings normal in patients with CO poisoning? And why?

I would guess it is because conventional ABG doesn't distinguish between carboxy- and oxyhemoglobin but I'm sure I could be wrong about this.
You mean SpO2, not PaO2. SpO2 is the % of hemoglobin saturation with O2. However, in the case of CO poisoning, the pulse ox doesn't distinguish between CO and O2 binding, so SpO2 will be normal or elevated, however the true SpO2 will be lowered. PaO2 is the amount of O2 dissolved in the plasma. There should be little, if any effect on PaO2.