Using hypocarbic gas for ventilation?

[sliceofbread136]

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I’ve had this though experiment in my head for awhile...

We could we not use a gas with a lower partial pressure of CO2 to ventilate a patient? Instead of 40 what if we used 20?

 

[Hopeful101]

Ok I'll HW help you...You need CO2 for acid base balance. That's a good start.

 

[sliceofbread136]

Ok I'll HW help you...You need CO2 for acid base balance. That's a good start.

Well that’s fairly obvious. But in the thought scenario we are in hypercarbic respiratory failure... as in too much co2 not enough ventilation to get rid of it.

To add more to a scenario let’s say this is a patient on max vent settings with a co2 of 90 and a ph of 6.9 who they are thinking of putting on vv ecmo. Why could I not walk in and run a gas with a Pco2 of 20 through the vent? Or even 10? Now with the ventilation I do have I am getting much more co2 diffusing out of the patients blood and we can titrate our gas and settings to get at a nice level of permissive hypercapnia, say 7.3.

Say your down side comes up and I get alkalotic, welp I’ll just pop down my respiratory rate or use a less hypocarbic gas.

 

[sliceofbread136]

The only thing I can find similar is the use of hypercapnic gas to lower the Qp of neonates will single ventricle physiology...

Which also brings up the possible use of hypocarbic gas for a ph crisis or tet spell?

 

[deleted87051]

The air we breathe is 78% nitrogen, 21% oxygen and less than 1% CO2. We never use an inspired gas with with a pCO2 of 40 to ventilate patients. The pCO2 of atmospheric air is 0.28mmhg. If we use oxygen enriched air to ventilate a patient, the inspired pCO2 is even lower.

 

[sliceofbread136]

The air we breathe is 78% nitrogen, 21% oxygen and less than 1% CO2. We never use a gas with with a pCO2 of 40 to ventilate patients.

So this is where I was mistaken. I assumed alveolar pco2 was the same as room air pco2 erroneously.

Thank you.

 

[deleted87051]

So this is where I was mistaken. I assumed alveolar pco2 was the same as room air pco2 erroneously.

Thank you.

Totally understandable. As an anesthesiologist, I stare at inspired and expired gases all day every day so I’m happy to share.

 

[WheezyBaby]

Ok I'll HW help you...You need CO2 for acid base balance. That's a good start.

If you're going to be snide you should have a clue of what you're talking about