Question Hypercapnia and oxygen toxicity

[Shi]

I saw a video about diving physiology on someone's phone yesterday.
"If a diver is taking a lot of carbon dioxide, and he's under high partial pressure of oxygen at that time, he's going to have oxygen poisoning, and the trigger is that he's hypercapnia."

Is this correct?

thanks

 

[broncobowsher]

I think something got lost in translation. Missing details. Out of context quote. Don't have the full story here.

Any chance you have a link to the article?

 

[Akimbo]

Hypercapnia (high CO2) is well known to increase the occurrence of oxygen toxicity.

Info - Oxygen Toxicity Limits & Symptoms

Oxygen Toxicity Limits & Symptoms Oxygen toxicity limits can be very confusing, especially for PPO2 (Partial Pressure of Oxygen) levels above 1.6 ATA used in chamber-based hyperbaric treatment (recompression) and decompression tables. For example, here is a chart of one of the most common DCS...

scubaboard.com

Scroll down to 3‑9.2.2.1 Factors Affecting the Risk of CNS Oxygen Toxicity. The exact mechanism is not fully understood.

 

[Shi]

我认为翻译中丢失了一些东西。缺少细节。断章取义的报价。这里没有完整的故事。

你有没有文章链接的机会？

It's a pity that I can't provide it to you because the narrator is Filipino and he is lecturing in not very proficient Chinese... Maybe his language is not very clear, but I almost copied his voice and wrote it here ...

Maybe that's what confuses me too, because in what I've learned so far, oxygen toxicity is related to exposure time.

Another reason is that extra movement causes the body to produce more carbon dioxide. But I'm not quite sure why too much carbon dioxide can cause oxygen toxicity?

 

[Shi]

Hypercapnia (high CO2) is well known to increase the occurrence of oxygen toxicity.

Info - Oxygen Toxicity Limits & Symptoms

Oxygen Toxicity Limits & Symptoms Oxygen toxicity limits can be very confusing, especially for PPO2 (Partial Pressure of Oxygen) levels above 1.6 ATA used in chamber-based hyperbaric treatment (recompression) and decompression tables. For example, here is a chart of one of the most common DCS...

scubaboard.com

Scroll down to 3‑9.2.2.1 Factors Affecting the Risk of CNS Oxygen Toxicity. The exact mechanism is not fully understood.

Thanks for the link, I'll check it out now!

 

[JonG1]

hypercapnia increases blood flow to the brain, and therefore increases the amount of high oxygen po2 that is delivered to the area that triggers a convulsion

 

[Akimbo]

Maybe that's what confuses me too, because in what I've learned so far, oxygen toxicity is related to exposure time.

If you are confused, so are a great many other readers that don't take the time to read Oxygen Toxicity Limits & Symptoms. There are a lot of contributing factors to oxygen toxicity:

• Individual Susceptibility
• CO2 Retention (Hypercapnia)
• Exercise
• Immersion in Water
• Depth (PPO2)
• Intermittent Exposure (reducing PPO2 for short periods)

 

[Akimbo]

hypercapnia increases blood flow to the brain, and therefore increases the amount of high oxygen po2 that is delivered to the area that triggers a convulsion

That is the prevailing theory but is far from proven or fully understood. We don't even understand why immersion makes OxTox so much worse.

 

[Shi]

hypercapnia increases blood flow to the brain, and therefore increases the amount of high oxygen po2 that is delivered to the area that triggers a convulsion

I think what you said was what he "missed"...

 

[Shi]

That is the prevailing theory but is far from proven or fully understood. We don't even understand why immersion makes OxTox so much worse.

I have bookmarked this very useful article and keep reading