Harmful effects of low oxygen for passengers

Seanaldinho said:
Not everyone handles hypoxia the same. The classic symptoms are euphoria, sluggishness, and etc. When I went through the altitude chamber I could realize how stupid I was becoming (we were doing the standard acuity tests so it was obvious) which is disconcerting and started to have a hot flash. A hot flash in your early twenties is not enjoyable.

Everyone reacts differently and starts to react at different O2 levels. Best not to run the risk and stick to the regs as a minimum and aim to provide oxygen well before that.
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The Regs don’t passengers to use oxygen, that’s the whole point of the question.
 
Observe the pax....if they start needing to use two hands to drink water, neurological dysfunction is occurring and you must act immediately to remove them from that situation
 
Salty said:
The Regs don’t passengers to use oxygen, that’s the whole point of the question.
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The FAA allows passengers to make their own decision and use the O2 at their discretion above 15k. Most people not being cognitively or physically active (things like flying the plane, writing a dissertation, or moving stuff in a cargo area) may not need O2 or notice anything different above 15k.

The risks are quite low, and as usual in aviation there haven't been that many cases that resulted in serious problems to necessitate a change in the regulations. The short term affects of hypoxia can be fixed by just a few minutes on O2 allowing people to return to normal, take off the O2, and go about whatever they were doing before if they wanted, until the short term affects come back. In a larger aircraft this means people could move around untethered if they want.

On the ground you would return to normal quickly, but enroute you could be uncomfortable (hot flashes like I had) for several hours or you could be euphoric and sleepy - this is probably another reason why it isn't mandatory. If you do want to get some shuteye being slightly hypoxic might help.
 
So, the wife and I are down in key west for lunch. We brought the dog. We cruised at 13.5 for a little over an an hour. We were on o2, but we just watched the dog close and she never even fell asleep. In fact, she jumped up about an hour in and stood looking out the window for the last 1/2 hour.
 
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Salty said:
So, the wife and I are down in key west for lunch. We brought the dog. We cruised at 13.5 for a little over an an hour. We were on o2, but we just watched the dog close and she never even fell asleep. In fact, she jumped up about an hour in and stood looking out the window for the last 1/2 hour.
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She's a good girl.
 
Salty said:
So, the wife and I are down in key west for lunch. We brought the dog. We cruised at 13.5 for a little over an an hour. We were on o2, but we just watched the dog close and she never even fell asleep. In fact, she jumped up about an hour in and stood looking out the window for the last 1/2 hour.
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PIREP a dog friendly place to eat close to airport?
 
She’s a great passenger, we fly with her a lot, but usually not that high.

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I’m glad we had the o2 for the trip back. We had to fly off the coast to avoid the storms and I liked being able to be up high to keep glide distance to the beach.

I’m still not sure how high is “safe”. I know at some point it becomes bad, but this thread didn’t help much.

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Nice pics!

You didn’t mention that the passenger was a wife. Wives consume an awful lot of oxygen....

:D
 
Pulse oximeters, monitor your passengers, have oxygen on board. Most importantly, if you have a passenger who is hypoxia below 10,000 ft, they should be examined by their physician. Not saying there will be something will be wrong, but like any “stress test”, it should be looked into. My mom, then age 80, had some visual hallucinations on a trip flying at 9500 ft. When we got her checked out, both her carotid arteries were 95% closed, no other symptoms.
 
Someone had to pick an altitude, they picked 15k for passengers. I believe the altitudes they picked are quite liberal and many of us will find we do better (experience/suffer fewer symptoms) when we use o2 at lower altitudes. As some have stated, different folks experience symptoms at different altitudes. Google apoptysis from hypoxemia; do you know when this happens to yourself or your passengers? Rhetorical question, the fact that you don't (none of us do) is reason to use o2. And o2 doesn't have to be expensive. You can roll your own.
https://www.pilotsofamerica.com/community/threads/renting-bottled-oxygen.87966/#post-1950076
 
Any of all y'all tried one of those self-contained O2 concentrators?
 
Salty said:
Seems like people are not understanding the questions being asked here.
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I think the question has been answered by several people. Long term affects are incredibly rare, short term affects will go away with oxygen either supplemental or provided by an altitude the passenger/pet is more used to.

15 is the number and there haven't been any issues that necessitated a change.
 
Seanaldinho said:
I think the question has been answered by several people. Long term affects are incredibly rare, short term affects will go away with oxygen either supplemental or provided by an altitude the passenger/pet is more used to.

15 is the number and there haven't been any issues that necessitated a change.
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Nope. 15 is not "the number" I asked for. That's the point that's being missed here. I could care less about the regulation. I'm looking for information on whether flying above 15,000, or even 12,500 without oxygen could cause a passenger long term harm. And preferably, what altitude should be considered a max for a couple hours of exposure.

If I have a passenger that doesn't want to use oxygen when I'm at 17,000 feet for two hours, I'm not going to use the regs to convince them otherwise, because the reg doesn't say he has to use it.

If I have to decide for a passenger (like my dog) whether they use it, I'd like to know more than I do now to make a good decision. There's been very little information presented here to help answer those basic questions. The best I can get out of the thread is "monitor them" or "give them oxygen". Neither answers the questions asked.

There is an altitude where long term harm will occur. Somewhere around 50,000 feet, you'll be pretty long term harmed without oxygen even if there only a very short time. I'd like to get something better than "somewhere between 0 and 50,000 MSL it can cause harm.
 
Pets would be my bigger concern, since they can't determine for themselves when they should go onto O2. It could be that the data you're looking for doesn't exist. So,....

1) Apply for a $250,000 USG research grant.
2) Round up a bunch of cats, toss 'em in the Mooney, and experiment.
3) Publish results.
4) Pocket the remaining $249,000.
 
Salty said:
Nope. 15 is not "the number" I asked for. That's the point that's being missed here. I could care less about the regulation. I'm looking for information on whether flying above 15,000, or even 12,500 without oxygen could cause a passenger long term harm. And preferably, what altitude should be considered a max for a couple hours of exposure.

If I have a passenger that doesn't want to use oxygen when I'm at 17,000 feet for two hours, I'm not going to use the regs to convince them otherwise, because the reg doesn't say he has to use it.

If I have to decide for a passenger (like my dog) whether they use it, I'd like to know more than I do now to make a good decision. There's been very little information presented here to help answer those basic questions. The best I can get out of the thread is "monitor them" or "give them oxygen". Neither answers the questions asked.

There is an altitude where long term harm will occur. Somewhere around 50,000 feet, you'll be pretty long term harmed without oxygen even if there only a very short time. I'd like to get something better than "somewhere between 0 and 50,000 MSL it can cause harm.
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I'm not a doctor, but I found this with Google: http://www.anesthesiaweb.org/hypoxia.php Apparently at that altitude, "long term" exposure can cause effects that take months to resolve. I did the hypoxic chamber ride with the FAA, and can say that the acute effects of <80% PO2 are extreme, but wouldn't be debilitating as an airplane passenger.
 
Lindberg said:
I'm not a doctor, but I found this with Google: http://www.anesthesiaweb.org/hypoxia.php Apparently at that altitude, "long term" exposure can cause effects that take months to resolve. I did the hypoxic chamber ride with the FAA, and can say that the acute effects of <80% PO2 are extreme, but wouldn't be debilitating as an airplane passenger.
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I haven't read the whole thing, but so far, I'm finding it more useful than anything else I've seen so far. Thanks!
 
Salty said:
Nope. 15 is not "the number" I asked for. That's the point that's being missed here. I could care less about the regulation. I'm looking for information on whether flying above 15,000, or even 12,500 without oxygen could cause a passenger long term harm. And preferably, what altitude should be considered a max for a couple hours of exposure.

If I have a passenger that doesn't want to use oxygen when I'm at 17,000 feet for two hours, I'm not going to use the regs to convince them otherwise, because the reg doesn't say he has to use it.

If I have to decide for a passenger (like my dog) whether they use it, I'd like to know more than I do now to make a good decision. There's been very little information presented here to help answer those basic questions. The best I can get out of the thread is "monitor them" or "give them oxygen". Neither answers the questions asked.

There is an altitude where long term harm will occur. Somewhere around 50,000 feet, you'll be pretty long term harmed without oxygen even if there only a very short time. I'd like to get something better than "somewhere between 0 and 50,000 MSL it can cause harm.
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Thank you for clarifying your question.

Above 26,000 the average person starts to die. People have done Everest without oxygen though, so the average person might get an hour or so, not that I would put my own skin on the line to test it. All people will react differently and all species will as well.

I think the confusion arose as I assumed we are talking about normal GA altitudes under 18. Answers like "monitor" come because this is a hard science with a soft answer that changes depending on the person or animal involved.
 
I am talking about under 18. And "starts to die" is a bit too late. lol So now you've narrowed it to 0 - 26,000 feet.

Actually, that link by Lindberg give me enough information to feel more comfortable with the situation.
 
I was thinking of a similar question. (I guess I'm glutton for punishment like @Salty, too!:D) Let's say we're flying along at 16 - 17k. We're all wearing O2 cannulas. My wife and/or daughter fall asleep. I look over and realize one of them has their mouth open, meaning they're not getting all the oxygen they should through the cannula. Do I wake them up and get them to close their mouth? Or, just figure it's pretty low risk since they're exhibiting no other symptoms and they're both healthy, athletic and have no confounding medial issues?

Taking it another step, let's say they have on a wearable pulse oximeter like this. At what SpO2 level do I need to wake them up and get them to close their mouth? Everything I've read is a minimum for the pilot. Surely a passenger can have a lower SpO2 without posing a threat.

Maybe @bbchien or another doctor could chime in.
 
The following article says “The brain gets affected when the SpO2 level falls below 80-85%.
Cyanosis develops when the SpO2 level drops below 65%.”

https://www.medicinenet.com/what_are_blood_oxygen_levels/article.htm

I think I would become concerned if spO2 was showing below 80 and would be willing to wake someone up to see how they are doing.

As noted above, the primary acute risks with these high altitudes are for people with other conditions that can turn out very poorly, such as causing heart attacks. Exposure over 4-6 hours can cause pulmonary or cerebral edema which are quite serious. But there is a lot of individual variability in how people tolerate these sort of things.

The military has studied this question - https://apps.dtic.mil/sti/pdfs/ADA575842.pdf
 
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As a pulmonary Doc, would recommend don’t do it. Someone mentioned mountaineers. Mountaineers tend to be very healthy people, and they don’t go from sea level to 17,500 feet in 30 minutes, it takes hours to days for them to get up there. The FAA regs are quite loose, even 14,000 doesn’t guarantee lack of harm to your passengers. When I was in practice in Denver, and current practice in the intermountain west. We still see high altitude sickness even at the lower elevations, some of which are fatal when affecting people with lung disease, heart disease, or cerebrovascular disease. And this is even at modest altitudes of the national parks and ski resorts. Most people acutely going to 17,500 feet will develop some kind of symptoms, ranging from mild to fatal. Really would not recommend it.
 
The answer to the question asked is “it depends”. The altitude at which each person begins to be affected by hypoxia and the altitude at which long term effects occur vary by person. Personal fitness plays a bit part on it. So there really isn’t a single answer. Some people can climb Mt Everest. Some people can’t even stay in base camp.

What altitude does it start to affect someone? Would you believe that effects start as low as 5k for some people? One of the first things that happens is a dulling of color vision, as I’m sure you’ve read by now.

It’s a question that I personally don’t intend to find out. Passengers with me will use oxygen at the appropriate levels because it’s the smart thing to do. Everyone reacts differently to hypoxia and I will not have unpredictable passengers on my airplane.

long term, the effects of low o2 can mimic dementia. One of my mother’s ailments at the end was copd, resulting in chronically low o2 levels. Even when her o2 was raised, the damage was done and she still had effects. I suspect but do not know that it happens slowly and incrementally, so even an hour has some small impact.
 
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Salty said:
I haven't read the whole thing, but so far, I'm finding it more useful than anything else I've seen so far. Thanks!
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>> Hypoxia quickly affects the higher centers, causing a blunting of the finer sensibilities and a loss of sense of judgment and of self criticism.

so, let the passenger control the XM radio. If they switch to country music, it's time to descend? ;)

 
I’ve done a chamber a lot in the navy, 25,000 ft.

Seen a number of guys get very belligerent (as in punches being thrown!), enough so it could be a problem.

Seen a bunch of folks in a jump plane to 18k. O2 is available, not always used, and of course not used for the last couple of minutes prior to drop as they get final hooked up and positioned, never seen any problem at all.

No idea about long term actual health problems.
 
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