"Bad" Partial Pressure of O2 at .17?

[Jax]

This is a pure curiosity question.

I picked up a new-to-me Predator. Because I live at altitude ~5000' I set the altitude to Auto.

Immediately, the computer flashed a red .17 --- meaning that the PPO₂ was lower than the limit amount of .19.

The Predator reports a pressure of 840mBars. So, the PPO₂ = .17 is correct.

So, I am living and breathing this "low" value of oxygen. One would assume the "altitude benefit" has me generating the red blood cells to carry more oxygen (IIRC).

That said, does that place me at a higher risk of oxygen toxicity since I can absorb more oxygen from the air at seal level?


I sure hope I asked that right . . .

 

[rigdiver]

It's giving a reading of the partial pressure, which you have already figured correctly. The 21% Oxygen is the same, just the molecules are farther apart, hence the lower ppO2. I hope I splained that correctly.
Now, something that was really cool was watching my old VR3's as Hurricane Rita's eye went overhead
60ish millibars is nothing to worry about in the scheme of things.

 

[Jax]

Agree.

People at altitude compensate by becoming able to carry more oxygen in the blood -- It's why the US Olympic bicycling team trains here, and other athletes train in Denver and other altitudes.

I'm wondering if that extra efficiency at carrying O₂ would make me more likely to OxTox faster. . . . Purely from a physiology point. Seem interesting.

 

[rigdiver]

Interesting for sure. Living at altitude causes you to produce more Red Blood Cells which equals a higher capacity to carry oxygen.
CNS oxtox basically comes from a large molecule forming in the nerve synapse causing transmission problems in the pathway. A signal travelling down a nerve is electrical till it reaches a synapse and then is chemical.
Pulmonary or whole body oxtox, is thickening of the lung tissue from breathing >0.5ppO2. In this case Oxygen is essentially "burning" lung tissue. OTU aka Oxygen Tolence Units is how we manage this form of Oxtox. Don't think coming down from your altitude to sea level will matter on this.
Have not heard of any tox situation related to living at altitude, yet.

 

[Jax]

Interesting for sure. Living at altitude causes you to produce more Red Blood Cells which equals a higher capacity to carry oxygen.
CNS oxtox basically comes from a large molecule forming in the nerve synapse causing transmission problems in the pathway. A signal travelling down a nerve is electrical till it reaches a synapse and then is chemical.
Pulmonary or whole body oxtox, is thickening of the lung tissue from breathing >0.5ppO2. In this case Oxygen is essentially "burning" lung tissue. OTU aka Oxygen Tolence Units is how we manage this form of Oxtox. Don't think coming down from your altitude to sea level will matter on this.
Have not heard of any tox situation related to living at altitude, yet.

Thanks - that's helpful. So the actual O2 molecule forms in the nerves?

 

[rigdiver]

Thanks - that's helpful. So the actual O2 molecule forms in the nerves?

Not actually "in" the nerve. The large molecule forms in the synapse of the nerve, which is a junction so to speak.
Think of one hand in a fist and your other hand forming a big letter C. Put the fist hand inside the C hand and it's a decent similarity.

 

[Jax]

Blood chemistry and the body's adaptive process is amazing! Thanks for the explanation.

 

[Dr Deco]

Hello Jax:

CNS Oxygen Toxicity

This is the toxicity that comes from elevated oxygen in the central nervous system and can lead to convulsions. The effect is caused by increased oxygen solubility in the serum and not in the red cells. These cells bind oxygen by a chemical bonding mechanism and the oxygen content in red cells is at a virtual maximum at normal atmospheric pressure.

You are not at a higher risk because you live at altitude.

Mechanism

It is believed that the toxicity problem is poisoning by an accumulation of “reactive oxygen intermediates” among which are free radicals.

Dr Deco :doctor:

 

[Jax]

Hello Jax:

CNS Oxygen Toxicity

This is the toxicity that comes from elevated oxygen in the central nervous system and can lead to convulsions. The effect is caused by increased oxygen solubility in the serum and not in the red cells. These cells bind oxygen by a chemical bonding mechanism and the oxygen content in red cells is at a virtual maximum at normal atmospheric pressure.

You are not at a higher risk because you live at altitude.

Mechanism

It is believed that the toxicity problem is poisoning by an accumulation of “reactive oxygen intermediates” among which are free radicals.

Dr Deco :doctor:

In the serum? That is really cool to know. Thanks for the lesson!