What you don't know about Hypoxia and G forces.

[LouDiamond 1]

I recently attended a lecture by the two gentlemen seen in the videos (Ted and Hans) on High altitude physiology and they brought this video segment that they did to my attention when I brought up how ill informed the general skydiving community is on this subject. While most Military MFF jumpers are familiar with most of this info, I find the average skydiver has little to no real useful information on the effects of G forces and the effects of Hypoxia and Decompression sickness. This information is good to know for everyone, even if you only go to 12.5k.

If you fly a canopy, no matter the size, a wingsuit or you participate in some of the larger formations that go above 12.5k, you need be aware of what could potentially happen to you. If you haven't taken a chamber ride before, I highly recommend you do. The videos won't provide you with what you need to know(which is why you should seek out more information) but hopefully they will show you and make you aware that what is typically taken for granted in civilian skydiving is considered one of the best ways to kill a human being. The title of the piece that the video is part of is called "How to kill a human being" and was done by the BBC. While the piece is focused on a different issue, the video pertains to what we in the skydiving community do on a constant basis.

While watching the videos think about canopy spins, especially those on pocket rockets or highly loaded canopies, and wingsuit flat spins when watching the section on G Forces. Most importantly, see that Hypoxia is deemed the best way to kill a person and you do not have to be at extreme altitudes to succumb to Hypoxia.

The G force portion starts at the 2 min mark. The Hypoxia/Decompression sickness portion starts at the 4:30 mark and continues into part 5 of the video series on YouTube.


Part 4, G forces and Hypoxia


Part 5, continuation of Hypoxia piece

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[kallend 1,621]

Thanks for the information, Scott.

...

The only sure way to survive a canopy collision is not to have one.

[antonija 0]

I watched these two parts and have one question: If you scuba dive and go too deep too fast, you get nitrogen high. You feel drunk, very confident, but your abilities to think properly are gone. I was taught that this is due to too high % of nitrogen in the blood.

In this show same symptoms show after rapid decompression, which I suppose is lowering air pressure just like on climb to altitude (so not lower % of oxygen (or higher % of nitrogen) in the air mix, just lower air pressure overall). So is this (drunk/euphoric) effect due to excess nitrogen, or insufficient oxygen?

Also what are best methods (must be some) to test if you're becoming hypoxic (probably some mental tasks but there must be few that "work for most")?

I understand the need for conformity. Without a concise set of rules to follow we would probably all have to resort to common sense. -David Thorne

[CSpenceFLY 1]

First signs of hypoxia are finger nails and lips turning blue

[skydiverkeith 1]

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First signs of hypoxia are finger nails and lips turning blue

This is not true. I've seen severe behavioral symptoms of hypoxia on someone with no physical symptoms.

Blue skies,
Keith Medlock

[billvon 2,384]

> If you scuba dive and go too deep too fast, you get nitrogen high.

That's nitrogen narcosis, and is caused by a too-high partial pressure of nitrogen.

Decompression sickness is quite different - but ironically is similar in rapid ascents in both skydiving and SCUBA diving. In DCS, nitrogen comes out of solution in your blood and forms bubbles. These can accumulate in your joints and cause joint pain, confusion, nausea, vertigo - a lot of things. It is treatable via recompression in a pressure chamber. Pure oxygen can also help.

To avoid it:

-NEVER skydive after SCUBA diving.
-When going to low altitudes (up to about 16,000) there's not too much of an issue.
-When going to mid altitudes (up to about 22,000) ensure a slow enough ascent that you can equalize nitrogen pressures as you go up.
-When going to high altitudes (26,000 and up) prebreathe pure O2 before the ascent to purge nitrogen from your bloodstream.

[billvon 2,384]

>First signs of hypoxia are finger nails and lips turning blue

First signs of hypoxia vary greatly. I had a friend in San Diego who was like a hypoxia canary; her lips would turn blue. Had another friend who would look fine but would start to drool. For me it's confusion and ringing in my ears. A chamber ride is a really great way to identify how each person reacts.

As a side note, I'm pretty susceptible to hypoxia on higher jumps (20K or so) so I've been using bailout oxygen on some of them. Usually I'll make the first few jumps with in-plane oxygen only, then when I start feeling it I'll start jumping with oxygen. The difference is remarkable; I see so much more on exit, I can identify sectors and radials that much faster, and I can even hear more.

So another way to see what hypoxia is doing to you is to make a jump with a bailout O2 system, and see what's different for you. I suspect most people will notice a difference even at lower altitudes (around 15,000 MSL which is not unusual at DZ's for 'regular altitude' jumps)

[antonija 0]

Nitrogen narcosis, thats it. And its symptoms are (wiki):
feeling of tranquility and mastery of the environment
(They also resemble (though not as closely) the effects of alcohol)
loss of decision-making ability and focus
impaired judgment, multi-tasking and coordination

And all this is apparently because of to much nitrogen in the blood. Exactly the same stuff that happens when there is not enough oxygen (hypoxia) in the blood (nitrogen levels not changed). So which one is it? Too much nitrogen or not enough oxygen? (if N2 % rises I guess O2 % must fall down, but which of these is primary cause and which one is consequence?)

DCS is quite different from anything shown in those clips but thanks for the info anyway.

Quote

These can accumulate in your joints and cause joint pain, confusion, nausea, vertigo - a lot of things.

You forgot about the ones that can come out in your brain and cause brain stroke... and death.

I understand the need for conformity. Without a concise set of rules to follow we would probably all have to resort to common sense. -David Thorne

[billvon 2,384]

>And all this is apparently because of to much nitrogen in the blood.
>Exactly the same stuff that happens when there is not enough oxygen
>(hypoxia) in the blood (nitrogen levels not changed).

I don't think they're quite the same, although some symptoms may be similar.

>if N2 % rises I guess O2 % must fall down, but which of these is primary
>cause and which one is consequence?

The partial pressure of both N2 and O2 increase with depth and decrease with altitude (unless you are using supplemental oxygen.)

[antonija 0]

I think it's time to do my NITROX specialty to learn these things a bit more...

I understand the need for conformity. Without a concise set of rules to follow we would probably all have to resort to common sense. -David Thorne

[JohnMitchell 14]

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First signs of hypoxia are finger nails and lips turning blue

Years ago, when considering some bandit High Altitude jumps, we read some of the symptoms of hypoxia.

-giddiness
-euphoria
-over confidence
-lack of good judgment

After reading that list, we realized we suffered from it while standing on the ground, and would not be able to tell the effects that high altitude jumping would have on us. We decided not to do the jumps.

[AndyBoyd 0]

Lots of interesting stuff to chew on as far as the death penalty debate. I won't divert the thread from the skydiving issues, but I might suggest posting these links in SC. It might spark some interesting discussion.

[sinjin 0]

I recently attended a training session that put us through hypoxia while doing mental tests. The website is:

http://www.factstraining.com/hypoxia-ROBD-news.shtml

For me, the first sign, was the feeling that i was not feeling quite right mentally. It sounds weird but it is a specific feeling. I think most airline personnel have to attend this type of training, so check major airports if you really want to find a chamber or machine to test it.

thank for the original post, good stuff to know and be aware of !!

dont let life pass you by

[jumpwally 0]

Now,,thats some funny shit ? +1

smile, be nice, enjoy life
FB # - 1083

[superstu 0]

this is a really good post and really hits home for me. actually i recently got very lucky under my Comp Velo 71 loaded at 3.0. The short version is i was about 1-2 seconds from complete black out after a violent opening and spinning. i was somehow able to pull negative G's, which is blood going to the brain and not the feet and which the body can't withstand as much as positive G's, and popped blood vessels in my mouth, eyes, and scalp. they said that at -3 G's you break blood vessels and at -5 G's you're blacked out, they think i was right around 4.5 or so. Nothing was wrong with any of my gear when i packed it or got it back and i have plenty of jumps on these size canopies, but this one definitely rocked my world. the incident was about 1.5 months ago now, and it took about 4 weeks for my eyes to get back to normal, i guess when i landed my eyes were literally popping out of my head due to the pressure. unfortunetly the pics i have are too big to post on dz.com.

Slip Stream Air Sports
Do not go softly, do not go quietly, never back down

[LouDiamond 1]

I think it's good that people are continually made aware of this issue as it really gets no mention nor thought as to the very real and present dangers skydivers put themselves into. However, it's not something that can be thoroughly explained over the internet or simply by picking up a book. The classroom training one goes through prior to taking a chamber ride is quite in depth and in some instances, video footage is provided to further drive home the point. One such video that was shown by Hans is quite an eye opener as it clearly showed the persons right side of the heart releasing nitrogen into the blood stream when the subject was directed to move their leg. It looked like the carbonation in a soda bottle rushing to the top after being shaken.

With more and more record attempts going higher in altitude and most having multiple ascents, sometimes rapid ones at that, in one day, the risk of DCS (decompression sickness) increases. The thought that a nasal cannula or sticking a tube in ones mouth when going to 18K or higher is all that is needed is wishful thinking at best.

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[kkeenan 13]

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The thought that a nasal cannula or sticking a tube in ones mouth when going to 18K or higher is all that is needed is wishful thinking at best.

Scott - You're right that very few civilian jumpers are exposed to the physiological training that they really should have. Thanks for the post.

I think it's common knowledge that a nasal cannula is not very efficient, and that the hose in the mouth is even less so. Do you know if any studies have ever been done as to how a cannula relates to a mask in O2 absorption ? It seems to me that the "hose inside the full-face helmet" method works well, but I don't know of any data to support that. This method was used by many on the 2006 World Team jumps as high as 24k - 26k with good results. That certainly doesn't mean that many people weren't partially hypoxic. It would be interesting to see that method tested.

Kevin K.

_____________________________________
Dude, you are so awesome...
Can I be on your ash jump ?

[billvon 2,384]

>I think it's common knowledge that a nasal cannula is not very
>efficient, and that the hose in the mouth is even less so.

Both are pretty 'efficient' in that they deliver most of the oxygen available to your lungs. The problems with them are:

1) Poor control of flow. Most systems out there are manifold-orifice systems (i.e. a long plastic tube with holes in them.) That provides poor flow regulation at best, and someone with a kinked or longer hose, or one at the end of the manifold, will not get the same flow.

2) The 'wavers.' Sticking the O2 hose in your mouth can cause problems with dry mouth and sickness (dirty hose + dry throat + high O2 environment is a very good environment for bacteria) but it does capture all the O2 coming out of the hose, and about 70% of that is actually used by your lungs.

However, a lot of people like to "wave" the hose near their mouth or nose. They like to feel the O2 hitting them in the face; they are reassured by this. This greatly decreases the amount of O2 available though.

3) Cannulas in freefall (for bailout systems.) I have no idea what 120mph of wind will do to the O2 flow out of the end of a cannula, but it isn't likely to be anything good. Cameramen will have this as an issue. Mouth usage might be a much better option for them.

> It seems to me that the "hose inside the full-face helmet" method
>works well,

Overall in terms of O2 efficiency I think this works least well. Helmets are designed to vent the air inside the helmet to the outside to prevent fogging, while preventing the wind from hitting your face directly. It vents oxygen as easily as air. It does have the advantage that you preserve some of the expired oxygen, but that's greatly dependent on the design of the helmet, the orientation of the hose and the position of the head within it. Two of my three helmets, for example, would not supply me with any O2 at all if I just put the hose inside the helmet, because my nose and mouth are up against the front padding, which is directly vented to the outside.

For best oxygenation you can't beat a dedicated mask. Heres's one: http://www.carltech.com/products/regulators-and-reducers/genaviatmask.htm I've been talking to these guys a bit and they think they can get the cost for the mask plus regulator under $1000.

[Beerlight 0]

Good info Lou... Everything you said is dead on.

[LouDiamond 1]

Quote

Do you know if any studies have ever been done as to how a cannula relates to a mask in O2 absorption ? It seems to me that the "hose inside the full-face helmet" method works well, but I don't know of any data to support that. This method was used by many on the 2006 World Team jumps as high as 24k - 26k with good results.

FACT: we are made up of:

78% Nitrogen
21% oxygen
1% other gases ( I call it burrito gas )


The issue here , and importance, is not so much about absorption as it is that the user is still breathing ambient air which is allowing the body to continue taking in nitrogen through normal respiration. This is where the danger is and the chances of DCS occurring. The other thing to keep in mind is that the effects of DCS doesn't always manifest itself while one is at altitude. Often times it can been seen at lower altitudes or even later on( we can also see effects of Hypoxia at altitude levels lower than most expect in certain circumstances). Which is why when you do a chamber ride and or go to the higher altitudes to jump you are told not to participate in any strenuous exercise for 24 hours following the exposure. Your body needs time to process the nitrogen that is in your system naturally, which is slowly over a minimum of 24 hours. Normal movement releases a good deal of that nitrogen into the body as it is and as I witnessed in the video I mentioned above. Hard exercise and or exertion would be like shaking a two liter bottle of soda and immediately taking the cap off and could lead to a DCS injury. It really is a razors edge as you might get away with it 99 times and have no issues but all it takes is that 1 time and no one can predict when it will happen.

This is the point that most people fail to grasp in civilian skydiving when we start talking about exposure above 18k feet. It doesn't matter what your O2 saturation is at that moment if you are still breathing ambient air. In my opinion, all you are doing is wasting aviator oxygen as you are barely staving off simple hypoxia but you are allowing the greater concern (DCS) to go unaccounted for by using cannulas/mouth to tube/tube in the helmet methods. The only solution to this is to use a mask that covers the nose and mouth and to not break the seal on that mask (ie: take it off or lift it up) once you start breathing O2. With that, prebreathing 100% O2 before hand for a minimum of 30 minutes/ Max 1 hour (altitude dependent) to purge the nitrogen in ones system before passing through 18K ft is needed. Lastly, continuing to wear that mask once ready to exit,moving towards the door, jamming the door and in freefall is also important.


This is where all the skydivers chime in and say " well we've been doing it for X years that way" and "The group that did the 1000 way that went to XXk ft didn't do that and they were fine". So why is this important? Because every time this is done, it's a dice toss and you can never predict when you will throw snake eyes. It's human physiology and like gravity, we know it exists, plus there is a right way and there is a wrong way to do this without people putting themselves at unnecessary risk.

The large portion of the problem is that there are no civilian O2 systems out there that addresses this issue when it comes to skydiving. There is also the issue that if there was a civilian system, it would be very expensive to own, operate, maintain properly and train the people maintaining and using it correctly.

"It's just skydiving..additional drama is not required"
Some people dream about flying, I live my dream
SKYMONKEY PUBLISHING

[RMK 3]

I have a scanned copy of the course notes from the CAMI Physiology Training (Hypobaric Chamber Day). It’s an 80page PDF and 7MB, but I could send it to someone to post for others if interested.

I did it a couple years ago at Andrews Air Force Base on a civilian training day in preparation for a 30K jump. The training is quite interesting and fun if you get the chance.

A cool item was a video shown to us just before the chamber session. If you get to the point of black out from hypoxia your brain erases the roughly last 30-60 seconds of short term memory (like losing the RAM in your computer). This guy (off O2) was being shown cards from a deck and calling them out then he gets stuck on one and as each successive card is shown, he keeps repeating (5 of Hearts, 5 of Hearts, 5 of Hearts) no matter what the card was. He’s about to drop and they put his mask back on; he quickly comes to and they ask “are you OK?” They start drawing cards again and when he calls the first one correct, they ask “are you sure it’s not the 5 of Hearts?” He looks at them bemused and didn’t understand it until they showed him the video afterwards.

Main 2 things I took away:

1. Everyone in the course experienced slightly differing onset of symptoms
2. After going hypoxic, you may not yet be unconscious but at that point you’re no smarter than a Cocker Spaniel and are capable of only the simplest of actions

"Pain is the best instructor, but no one wants to attend his classes"

[skydiverek 54]

Everyone should watch this video. The cameraman was also very hypoxic, that's why he did nothing to stop the events:

http://www.youtube.com/watch?v=tXa4w4aYKEk

[piisfish 135]

Quote

FACT: we are made up of:

78% Nitrogen
21% oxygen
1% other gases ( I call it burrito gas )

check your facts....
for example HERE

what we breathe is not what we are made of

Quote

Dry air contains roughly (by volume) 78.09% nitrogen, 20.95% oxygen, 1% burrito gas. Air also contains a variable amount of water vapor, on average around 1%.

Actually I think that skydivers have at least 5% burrito gas

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

[AndyMan 7]

Quote

Everyone should watch this video. The cameraman was also very hypoxic, that's why he did nothing to stop the events:

http://www.youtube.com/watch?v=tXa4w4aYKEk

Absolutely amazing footage. Thanks for posting that.

_Am

__

You put the fun in "funnel" - craichead.

[Dano302 0]

holy shit! i hope he got to his handle before his aad fired!