Hypoxia at 21000 ft.

[billvon 2,413]

>Can you give the references about this claim?

Can't find em now. Basically it's becoming more of an issue as people fly higher-powered GA aircraft that can climb in excess of 2000fpm and cruise above 20,000 feet.

>DAN (Divers Alert Network) has done extensive research to the
> development of DCS during flying and their findings are not in line with
> your claim of developing DCS.

I've seen DAN's research on airline passengers, but I haven't seen anything from them on fast-climbing unpressurized aircraft.

[SkymonkeyONE 3]

My old roommate, US Airforce Tsgt Ron "Body" Plunkett got bent (actual DCS) from too many evolutions up and down as a HALO instructor when he was assigned at Yuma. He was dismissed from flight status of all kinds as a result. Yes, it can happen.

Chuck Blue

[SkymonkeyONE 3]

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I've seen DAN's research on airline passengers, but I haven't seen anything from them on fast-climbing unpressurized aircraft.

Like the old C-141's, C-17's, and even C-130's used routinely for military freefall operations at Yuma Proving Grounds, AZ during the basic MFFPC, the MFFJM course and the AMFFQC. This is particularly relevant for the instructors who go up and down on multiple sorties evaluating students all day long.

[Beerlight 0]

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"Even so, pilots with fast-climbing aircraft are getting DCS (decompression sickness) from climbing to even 20,000 feet rapidly."

Can you give the references about this claim? DAN (Divers Alert Network) has done extensive research to the development of DCS during flying and their findings are not in line with your claim of developing DCS.

The following scientific articles (also Air Force research) from an earlier date conclude that DCS is not a significant risk below 21.000ft.

DCS should NOT be confused with hypoxia as is common.

Files DS, Webb JT, Pilmanis AA.
Depressurization in military aircraft: rates, rapidity, and health effects for 1055 incidents.
Aviat Space Environ Med. 2005 Jun;76(6):523-9.

Haske TL, Pilmanis AA.
Decompression sickness latency as a function of altitude to 25,000 feet.
Aviat Space Environ Med. 2002 Nov;73(11):1059-62.

Although most of my work in the Air Force dealt with DCS from being exposed to high altitudes/low pressures, you can bet you can get "the bends" from a rapid climb. I should know, cause it's happened to me on two occasions. In an alitude chamber of course while I was performing research FOR Dr. Webb and Pilmanis at Brooks AFB, TX.

[dorbie 0]

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It's this callous disregard for safety as it relates to proper O2 operations that is, without a doubt, going to get somebody killed soon.

Hypoxia may have already contributed to the three fatalities in the Antarctic 4-way that went in.

From:
http://home.online.no/~trjacob/english/diary.htm

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Sydpolteamet had already, at Patriot Hills, asked for supplemental oxygen for use in the Twin Otter at the South Pole. We were told that "this would probably not be necessary". We knew that oxygen at the jump altitude at the South Pole would be absolutely necessary. We also knew that the doctor would bring two bottles for use in an emergency. At the South Pole Trond asked again for oxygen and the pilot on the Twin Otter had one oxygen bottle with one oxygen mask connected. Trond asked if it was ok to use this in the plane while we were climbing to exit altitude. The pilot agreed to this. Then we didn't have to use the emergency bottles. We could pass the oxygen mask around in the plane. This was not the way it should have been, but it was the second best that we could get. Everybody should of course have his own mask.

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Trond turned on the oxygen flow and started to breathe oxygen. He then passed it to Morten whom breathed and passed it to Michael. When he had breathed he passed it to Hans, but he just nodded his head. He would not take any oxygen. Steve and Ray also refused to take oxygen. It seemed like they were just to busy preparing Ray's camera helmet. The same thing happened every time we tried to pass the oxygen mask around.
Close to exit altitude the 4-way team, with Steve, Ray, Hans and Michael, got in the back of the Twin Otter preparing for the exit. Sydpolteamet had already been strapped together for the tandem jump, and waited a bit closer to the front of the cabin. Sydpolteamet was still breathing oxygen.

[Fast 0]

Since this got bumped up,

Anyone know what is more effective? Cannulas or masks? Is either one prefered for jumps up to FL18?

~D
Where troubles melt like lemon drops Away above the chimney tops That's where you'll find me.
Swooping is taking one last poke at the bear before escaping it's cave - davelepka

[billvon 2,413]

>Anyone know what is more effective? Cannulas or masks?

Masks are more effective overall. Cannulas are usually sufficient, and work better with full face helmets. Oral tubes work OK as well if they are used correctly (they are often not.)

For FL18, all three should be sufficient. I've gone as high as FL26 with oral and cannula delivery methods.

[Fast 0]

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>Anyone know what is more effective? Cannulas or masks?

Masks are more effective overall. Cannulas are usually sufficient, and work better with full face helmets. Oral tubes work OK as well if they are used correctly (they are often not.)

For FL18, all three should be sufficient. I've gone as high as FL26 with oral and cannula delivery methods.

Thanks much

~D
Where troubles melt like lemon drops Away above the chimney tops That's where you'll find me.
Swooping is taking one last poke at the bear before escaping it's cave - davelepka

[Mozencrath 0]

Did anyone ever see the mini-series on The Discovery Channel: "Everest: Beyond the Limits"

If not, it's great. Mountain climbing has nothing to do with skydiving, but these guys start out in Kathmandu (10,000ft) and over a 6 week period they gradually move there way up to almost 30,000ft.

That will give you a first hand look at what a lack of oxygen does to a human. Some of the climbers spend WEEKS aclimating there bodies to the change in oxygen levels and they still can/do die. Everest is actually not a technical or difficult mountain to climb. It's the fact that the mountain is located in a place where no life can survive because of the oxygen levels. Check it out!

[Mozencrath 0]

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>Anyone know what is more effective? Cannulas or masks?

reply]

Nasal Canula's only go up to about 6LPM and only go through the nasal passages. NRB Masks cover the mouth and nose, and if my training serves me correctly, can deliver 15 or 30LPM of oxygen. Nasal canulas are useless....

• Quote

[kkeenan 13]

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Anyone know what is more effective? Cannulas or masks? Is either one prefered for jumps up to FL18?

The most popular method I've seen lately is the full-face helmet with hose inserted into the face area of the helmet. (slide the hose between the cheek and helmet padding) This fills the face area with O2, and is a very practical delivery system. When it's time to disconnect, just pull the hose out and go. This works best when inhaling through the nose and exhaling through the mouth. It would be interesting to see blood )2 sat. levels of the various methods.

Kevin

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

[billvon 2,413]

>The most popular method I've seen lately is the full-face helmet with
>hose inserted into the face area of the helmet. (slide the hose between
>the cheek and helmet padding) This fills the face area with O2, and is a
>very practical delivery system.

In my experience, this is one of the least reliable systems out there. The porosity of the helmet is uncontrolled; indeed, during WT06 I recall seeing one jumper with the hose in the side of her helmet with most of the O2 blowing out the crack in the top of the faceshield. In my case, my nose and mouth were smashed up against the padding in the front of the helmet, so most of the air I was breathing came from _outside_ the helmet. Good for not fogging, bad for O2 delivery. I dealt with that by squeezing the cannula between my nose and the padding so it was functioning as a cannula normally does (blowing into my nose.)

The 300-way system wasn't too bad (nasal cannula integrated into the helmet) but needed some additional work before it was clean.

[billvon 2,413]

>Nasal canulas are useless....

They seem to work well up to 26,000 or so. Keep in mind that at 26,000 feet you only need 3lpm O2, although we were running the system at much higher flow rates "just in case."

[Legs 0]

Its interesting that everyones quoting LPM of O2. Whats important is the inspired % of O2. The manufacturer of the cannulae or masks used should include a slip of paper in the package which tells you what % you will be inspiring at what lpm.

For example.
nasal cannulae
2lpm = 24%, 4lpm = 28%, 6lpm = 35%

Face mask
2lpm = 28%, 4lpm = 35%, 6lpm = 40%, 8lpm= 50%, 10lpm = 60%

from the example above you can see that you can get a higher inspired oxygen for lower oxygen usage with a mask. So it depends on what inspired % you want and how much O2 supply you've got. Note if you use masks not cannulae you will use less O2 up and save $

With love in Christ

[billvon 2,413]

>from the example above you can see that you can get a higher
>inspired oxygen for lower oxygen usage with a mask.

And with an oxymizer you can get a higher inspired oxygen content from a cannula than from a mask. We generally don't have to worry too much about this in sport skydiving; we don't need much supplemental oxygen at the altitudes we usually go to.

[kallend 1,635]

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>The most popular method I've seen lately is the full-face helmet with
>hose inserted into the face area of the helmet. (slide the hose between
>the cheek and helmet padding) This fills the face area with O2, and is a
>very practical delivery system.

In my experience, this is one of the least reliable systems out there. .

We were told to use this method at the Z team this year, and I did not hear of anyone having any problems with it at 20k. I certainly didn't and I'm OLD with an old cardiovascular system. I also used the method at the TSR with no problem at 21k. I was wearing an OXYGN with a tight fitting face shield and I was careful about exactly where the hose was located.

...

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

[LouDiamond 1]

I concur that nasal cannulas are basically useless above 18k. Any system that allows you to continue breathing ambient air at altitudes from 18K and higher(more so on the higher end) you greatly increase the chances of a DCS injury. Nitrogen is the enemy and if it isn't properly purged from ones system, hypoxia is the least of your worries at the higher altitudes.

My concern with the continued RW bigways going higher isn't so much the the hypoxia issue, its with the increased risk of DCS which may manifest itself during or after a jump. This especially holds true when multiple rapid ascension lifts to higher altitudes are carried out in one day for a period of several consecutive days without allowing the proper amount of time for the body to deal with any nitrogen bubbles in the system. Mark my words, if the RW bigway attempts continue to go to higher altitudes, it will only be a matter of time before we see a DCS related injury. The only physiological proven way to prevent this is to pre breath, use a mask and a bail out bottle system on each jumper. Short of that, its just a crap shoot and a matter of time before someones number comes up.

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

[Peterkn 17]

I think there are a few more issues than simply choosing the most efficient O2 delivery system.
If you were just taking a ride to altitude then descending in the aircraft it would make sense to use an O2 mask, but if you’re going to exit at altitude then you’d need to transition from the mask to another oxygen delivery system at some point before exit – which can undo the benefits of using the mask in the first place.

During the warm-up jumps for WT04, I was wearing a bonehead helmet with a side mounted video camera. I took my own oxygen mask along to the event, and at about 3 minutes before exit I’d take the mask off, put my goggles and helmet on, put the mask down my jumpsuit and zip my jumpsuit up. During this time I’d disconnect the hose from the mask and put it in my mouth, and I’d continue to breathe the O2 in this way until exit.
On one of these jumps I had severe sinus pain in freefall, but I believe that I was probably suffered from hypoxia as well. I ended-up in the wrong sector, and was feeling quite confused and dazed when I landed. I guess this could have just been down to the sinus pain and decongestant medication I’d been taking, but it felt like more than that.
After standing-down for a couple of days to give the sinus problems a chance to subside, I started wearing my full-face and putting the O2 tube up between my cheek and the padding so that the end was just below my nose. I immediately felt much happier about the way my skydives were going.

Because I’d had this problem on 2004, and the WT06 jumps were likely to be from higher altitude, I decided to buy a pulse oxymeter that I could use to monitor my O2 saturation levels on the ride to altitude.
The pulse oxymeter is the type that slips over a finger, so I’d normally use it until we were about 3 minutes from exit, at which point I’d put it away and put my remaining glove on. On the ground it would normally read 99% (it only has a 2 digit display, so it can never indicate 100% saturation).

Before going to Thailand for WT06, I started gathering some data on what happens on a normal ride to around 13k, then what happens when you go to 16.5k with O2 being used from 12k.
The results were quite interesting, and I realised that posture and breathing technique play a big part in your O2 saturation levels. If I sat up straight and breathed using my diaphragm then my saturation would be around 96% at 13k without O2. If I sat slumped on the floor, relaxed and breathed in a normal manner then saturation would be down to the low 90’s, and on one occasion I fell asleep on the way to altitude and my saturation was down 88% when I awoke at around 10k.

When using O2 from 12k, my saturation would be back up to around 98% within 60 seconds of going on to the O2, regardless of how low it had fallen beforehand. By 16k it would usually have fallen slightly, but would still be in the mid to upper 90’s. I’m not sure what flow rate was being used, but these tests were done in one of the Perris Otters, so I guess would be typical of the delivery systems that you’d encounter at most regular DZ’s.

On WT06, my O2 saturation never dropped below 94% once we were breathing O2, and it was usually around the 96 to 97% mark. The aircraft would usually climb to almost the full exit altitude before starting their long run-in, and on one jump we spent well over 30 minutes at or above 24k.

Of course, just having the feedback from the oxymeter has an effect on your saturation levels. Seeing a high saturation level reassures and relaxes you, which has a positive effect. If you see the saturation level dropping you have the opportunity to do something about it and you get immediate feedback on the effectiveness of your actions. The downside could be that you become anxious if your saturation levels start to plummet, which would make the situation worse, but at least you’re in a position to identify the problem and either fix it or chose to stay in the aircraft.

I tried doing a few other tests on jumps from normal altitudes, and was quite surprised what a negative effect simple actions like putting your helmet on, getting up off the floor and giving yourself a gear check can have on your saturation levels. This is one of the reasons why I like the idea of putting your helmet on just before going on to O2. The idea that you also have a helmet full of O2 when you exit - which will help you during the freefall phase of the jump - sounds nice, but in reality I doubt that it really works that way. To me the biggest advantage of delivering O2 direct into your full-face helmet is that your helmet is already on your head, so it’s one less thing to do before exit.

As many bigway organisers are now mandating the use of full-face helmets on their dives, I don’t think it’s practical to use O2 masks because of the issues involved in changing over from the mask to the full-face helmet just before exit. If you can manage to wear a nasal canular under your full face, and are happy to keep it on during freefall, then I’d say that this is probably the best option. If not, then it’s probably best to go for putting the O2 tube into your helmet as previously described.

Either way, I can strongly recommend the use of a pulse oxymeter as a way of monitoring your saturation levels if you’re going to be doing a fair bit of high altitude jumping. The one I have cost around USD 150 and is small enough to slip into a jumpsuit pocket. I’m not sue how accurate it really is as I’ve never calibrated it against a more expensive device, but I’m not sure that it really matters - just so long as it’s consistent in the results it gives.

Pete.

[headcase 0]

I was fortunate enough to attend Johnny B West's (JBW)respiratory physiology lecture series in the 80's. JBW is the father of high altitude physiology. He suffers from long-term sequelae as a result of all of his physiology testing in hypoxic environments and will be the first to tell you it is stupid to mess with hypoxia. Even small doses can have an effect on watershed areas of the brain. I think too many skydivers are cavalier when it comes to the effects of hypoxia and tightening of regs with regard to O2 in the context of sport skydiving would probably be a good idea.

[LouDiamond 1]

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but if you’re going to exit at altitude then you’d need to transition from the mask to another oxygen delivery system at some point before exit – which can undo the benefits of using the mask in the first place.

Take a look at the existing military systems. The way to avoid what you just described is to have a system that allows you to hook up to an O2 console while on the plane thats in line with your bail out bottle system. When it's time to exit, everyone stands up and turns on their bail out bottle and then disconnects from the onboard O2 console. No need to remove the mask and no risk of breathing ambient air and re introducing nitrogen into your system. Short answer, use a valve. Thats an oversimplification but it's basically what it is.

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I started gathering some data on what happens on a normal ride to around 13k, then what happens when you go to 16.5k with O2 being used from 12k.

Keep in mind that data is accurate for you and your physiological state at that point in time. Aging, smoking, medications, diet,sleep can and do influence a persons reactions at altitude and are subject to change.

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The aircraft would usually climb to almost the full exit altitude before starting their long run-in, and on one jump we spent well over 30 minutes at or above 24k.

The danger people need to realize when at these higher altitudes is that hypoxia is the least of your worries. DCS illnesses are what is going to more than likely change your life forever if not kill you, especially when making multiple ascents to these altitudes without allowing time for the body to process the nitrogen in the system. Anything short of a full face mask is useless as you can still breath ambient air and introduce nitrogen into your system. Frankly, a pulse oximeter is not going to do you any good other than telling you you're not getting enough oxygen at a certain point in the plane ride. If you don't have an O2 system on board thats capable of providing that needed O2, the pulse oximeter information is pretty much useless,more so at higher altitudes where nitrogen in your system is the concern ,which is were RW bigways are headed.

There is a way to build a skydiver friendly O2 system that can incorporate either a full face or open face helmet as well as all the associated equipment.The problem is that the people who build O2 systems don't have any interest in investing in a project that has a very small clientele base. Plus the equipment is not cheap and it requires maintenance and people trained in its use.

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

[millertimeunc 0]

+1 To everything Scott said.

I'm im Phase 1 of pilot training at Columbus AFB, and we did the altitude chamber today, going up to 35k feet, then down to 25k and taking our masks off until we got some initial symptoms of hypoxia. Not much to add, suffice to say that hypoxia and DCS are nothing to mess around with.

The best things in life are dangerous.

[Beerlight 0]

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+1 To everything Scott said.

I'm im Phase 1 of pilot training at Columbus AFB, and we did the altitude chamber today, going up to 35k feet, then down to 25k and taking our masks off until we got some initial symptoms of hypoxia. Not much to add, suffice to say that hypoxia and DCS are nothing to mess around with.

I'll be damn! I was the NCOIC of the Columbus chamber unit! Before I retired in 2004. I heard all the Tweet's were gone? Good luck w/ everything!

[NWFlyer 2]

Bumping this thread because the video was posted again and people are asking all the same "Why didn't anyone do anything?" questions that have already been asked and answered in this thread.

Plus it's a really damned educational video/thread.

"There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences." -P.J. O'Rourke

[danielcroft 2]

Thank you for bumping!

[phoenixlpr 0]

I've seen lips of my friends turning purple just ridding a Caravan to 4000m without door....just 15 min from the ground level...