Flying High and O2

Somedudeintn

Somedudeintn

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somedudeintn
I’ve done a few flights at 10.5 and 11.5 at night and never checked my SpO2 levels. I picked up a pulse oximeter and would see 95-98% on the ground. I took a 4.5 hour flight each way this weekend (my longest flight yet) and flew at 8000 there and 9000 back.

I was surprised to see a lower SpO2 number even at those altitudes. The lowest I saw was 84, and was typically 88-94. I was able to get to 95 by focusing on breathing more deeply after I noticed a lower number. I’m in my mid thirties and exercise about once a week.

Anyway this is my Psa that I was surprised by lower numbers even below 10,000. I bought an E size O2 tank with a regulator and cannulas and masks off craigslist for $35 and plan on getting it filled at the airport tomorrow for $25.

I’m going to start planning on having O2 available for me on flights above 8000ft. I’m excited about some more options for flying higher too.

Anyway the PSA is to pick up a pulse oximeter and check your O2 saturation at altitude. You may be surprised.
 
Indeed! There is a reason that 5,000 at night is recommended..

I was non PIC and non flying pax at one of those higher altitudes where oxygen has to be available to me but was not required, so out of curiosity I spent some time with the cannula off to see how I felt and what I would see.. I saw 85. I felt perfectly fine, but I wonder if having to do math or make complex judgments I would have noticed an impairment

Use the O2

Good PSA thanks

PS - skiing at elevations around 12,000 ft or higher, I have definitely noticed that I got exhausted much faster.. but I've never noticed an emotional or psychological impairment
 
Thanks for the info.
 
Yep, skiing over 11K has always been an issue for my wife, so we go to Steamboat almost exclusively now. And the snow there is just fantastic anyways, we're looking for trees and groomers not steeps.
 
Makes sure you get a hydrostatic test on the tank before filling it. IRCC there’s a mandatory 5 yr requirement for testing tanks. Verify the regulator, too.
 
murphey said:
Makes sure you get a hydrostatic test on the tank before filling it. IRCC there’s a mandatory 5 yr requirement for testing tanks. Verify the regulator, too.
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Thanks for the info. The tank is stamped 2015 so I’ve got a little time left before the test is due again. The regulator looks brand new. Once I get it filled I’ll connect everything up and briefly test it before I go up in the plane and use it. I called a local scuba place and a welding/medical o2 place and neither would fill it. I’ll try to get an o2 rx next time I visit the dr so I can get it filled a little more easily and cheaply.

Either that or I may get my own transfill setup.
 
Somedudeintn said:
...I was surprised to see a lower SpO2 number even at those altitudes. The lowest I saw was 84, and was typically 88-94. I was able to get to 95 by focusing on breathing more deeply after I noticed a lower number. I’m in my mid thirties and exercise about once a week...
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My personal limit is 90 while flying.

There's an age correlation as well. We old geezers should be on O2 a lower altitudes than those insolent young Millenials. :D
 
I live at 6500 feet. I usually see 94-96% on the ground. I have never checked at altitude because I was flying pressurized aircraft at the time.

You will like flying at higher altitudes. Life begins at 18,000.. ;):)
 
My house sits at 6394 MSL and my airport at 6880 MSL. I see a resting SpO2 of 97 or so even though I more than qualify as an "old geezer"! I don't start to use O2 until I am above the 12.5 k level for more than 30 minutes per the regs but even then my small SkyOx O2 bottle has lasted for years and years because I use a pulse oximeter to keep the SpO2 at or above 90 but the O2 flow is very low. I don't use O2 at night below 12.5 k but again it is because I live at this altitude. But I well know how folks from the low country can experience O2 issues. When we moved here 39 years ago from low elevation it took on the order of 6 to 8 weeks before we felt like doing much exertion!!!
 
I'm in the same group as Arrow76R. I grew up at 7,000' and now live at about 5,000' and don't really see a drop below 90 until I am at 13K or higher. Almost all my flights are between 11K and 13K.
 
For those flying at night, remember that the use of O2 can be helpful at lower altitudes than 12.5, perhaps down to 6-8 thousand feet. The helpful part isn’t the typical hypoxia issue that the Regs are based on. Instead, it’s simply to assist your color vision and dark adaptation, which begin to become affected much lower than 12.5k, and for obvious reasons are so much more important at night.
 
There is a correlation between residence altitude and susceptibility to hypoxia. Those of us living at higher altitudes (5500MSL for me) have haemoglobin adaptation to allow greater affinity for oxygen at lower partial pressures. This means that for a given partial pressure of oxygen our saturation is higher than those living at sea level. I also chuckle at the recommendation for oxygen at night at altitudes >5000ft - this would mean I’d need oxygen to taxi to the active....

given all of this however, I still prefer to use oxygen above 10,000 - I find that for the very low flow rate <1lpm I have my sats well above 96% and I feel much less tired on arrival. The first long X-C I did was 550nm at 12,000 without oxygen and I could not stay awake for the rest of the day. No more.

I’m surprised the dive shop wouldn’t fill your cylinder - I have 2 Aerox cylinders and the local dive and welding gas supply shop is very happy to fill. I pay about $20US for the E tank.
 
Tantalum said:
PS - skiing at elevations around 12,000 ft or higher, I have definitely noticed that I got exhausted much faster.. but I've never noticed an emotional or psychological impairment
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Hypoxia is insidious.
 
I find that my readings decline above FL055. On my last flight I was cruising at 7.5 and I was reading 85-88% on the oximeter. Dropped to 5.5 and went to 95-98%. What a difference a few thousand feet make. I’m going to start with the disposable canisters, until I find the resources $$$ to purchase a 2 place system.
 
That's the problem with pulse oximeters. They tell you this stuff. If you didn't have one you wouldn't know and would just keep going on your merry. I kinda a little bit feel the same way about engine monitors.
 
Anyone have a specific pulse oximeter they reccomend for flying? I need to buy one.
 
steingar said:
That's the problem with pulse oximeters. They tell you this stuff. If you didn't have one you wouldn't know and would just keep going on your merry. I kinda a little bit feel the same way about engine monitors.
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yup....sometimes it's better to just be oblivious. ;)
 
steingar said:
That's the problem with pulse oximeters. They tell you this stuff. If you didn't have one you wouldn't know and would just keep going on your merry. I kinda a little bit feel the same way about engine monitors.
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Wait, what?
 
Kenny Phillips said:
Hypoxia is insidious.
Click to expand...
That was sort of the point of my experiment, I forget the exact altitude but it was 15K or higher.. I was provided with O2 and started at 98%.. took the cannula off and chilled for a bit, O2 got down into the low 80s, I forget the exact number but I know it wasn't in the 70s. I felt completely fine.. which was the scary part, since you really would **NOT** recognize it if you didn't have an oximeter. Put it back on and I was right back at 98% in a matter of moments

Checkout_my_Six said:
sometimes it's better to just be oblivious
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flying without one (an oximeter) seems suicidal (assuming you're spending a lot of time at 10K or higher)

Salty said:
Wait, what?
Click to expand...
and you thought I wasn't that bright..
 
Tantalum said:
That was sort of the point of my experiment, I forget the exact altitude but it was 15K or higher.. I was provided with O2 and started at 98%.. took the cannula off and chilled for a bit, O2 got down into the low 80s, I forget the exact number but I know it wasn't in the 70s. I felt completely fine.. which was the scary part, since you really would **NOT** recognize it if you didn't have an oximeter. Put it back on and I was right back at 98% in a matter of moments


flying without one (an oximeter) seems suicidal (assuming you're spending a lot of time at 10K or higher)


and you thought I wasn't that bright..
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With you I was just kidding. ;)
 
Since I don't fly a pressurized aircraft, for the Piper Malibu drivers out there is there an emergency oxygen system should you lose pressurization? Or how do you actually know if you something bad is happening? What's the emergency descent procedure like.. just go flat pitch and get down fast?

In an unpressurized Cirrus it's up to you, the pilot, to keep tabs on your (both plane and personal) O2 levels.. is the operating paradigm different in a pressurized craft?
 
DesertNomad said:
If you visited me, you'd need oxygen sitting in my living room I guess.
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maybe.... :D

giphy.gif
 
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Mike Blackburn said:
Those of us living at higher altitudes (5500MSL for me) have haemoglobin adaptation to allow greater affinity for oxygen at lower partial pressures.
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Those of you that live at higher altitudes have higher levels of 2,3-bisphosphoglycerate (2,3-BPG), a molecule that LOWERS the O2 affinity of hemoglobin. I know that sounds counter-intuitive, but lowering O2 affinity of hemoglobin allows it to release more of its O2 load in peripheral tissues. The binding curve of hemoglobin is sigmoidal, not linear or hyperbolic, with pressure. Hemoglobin in the presence of 2,3-BPG still saturates fairly well at the partial O2 pressures in the lungs, even at moderate altitudes typical of GA, but is dramatically better at dropping its load of oxygen in the peripheral tissues, where the partial O2 pressure is very low.

Anyone who stays at altitude for 2-3 weeks will start to benefit from higher 2,3-BPG levels, but the effect will slowly diminish when you go back to the lowlands as your 2,3-BPG levels gradually return to their former concentration. This temporary effect is why long distance runners train at high altitude for an extra edge when competing at a lower altitude.

Biochemistry is amazing stuff...
 
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chemgeek said:
Those of you that live at higher altitudes have higher levels of 2,3-bisphosphoglycerate (2,3-BPG), a molecule that LOWERS the O2 affinity of hemoglobin. I know that sounds counter-intuitive, but lowering O2 affinity of hemoglobin allows it to release more of its O2 load in peripheral tissues. The binding curve of hemoglobin is sigmoidal, not linear or hyperbolic, with pressure. Hemoglobin in the presence of 2,3-BPG still saturates fairly well at the partial O2 pressures in the lungs, even at moderate altitudes typical of GA, but is dramatically better at dropping its load of oxygen in the peripheral tissues, where the partial O2 pressure is very low.

Anyone who stays at altitude for 2-3 weeks will start to benefit from higher 2,3-BPG levels, but the effect will slowly diminish when you go back to the lowlands as your 2,3-BPG levels gradually return to their former concentration. This temporary effect is why long distance runners train at high altitude for an extra edge when competing at a lower altitude.

Biochemistry is amazing stuff...
Click to expand...

Interesting! Are those living at higher altitudes producing more red blood cells as well?
 
chemgeek said:
Those of you that live at higher altitudes have higher levels of 2,3-bisphosphoglycerate (2,3-BPG), a molecule that LOWERS the O2 affinity of hemoglobin. I know that sounds counter-intuitive, but lowering O2 affinity of hemoglobin allows it to release more of its O2 load in peripheral tissues. The binding curve of hemoglobin is sigmoidal, not linear or hyperbolic, with pressure. Hemoglobin in the presence of 2,3-BPG still saturates fairly well at the partial O2 pressures in the lungs, even at moderate altitudes typical of GA, but is dramatically better at dropping its load of oxygen in the peripheral tissues, where the partial O2 pressure is very low.

Anyone who stays at altitude for 2-3 weeks will start to benefit from higher 2,3-BPG levels, but the effect will slowly diminish when you go back to the lowlands as your 2,3-BPG levels gradually return to their former concentration. This temporary effect is why long distance runners train at high altitude for an extra edge when competing at a lower altitude.

Biochemistry is amazing stuff...
Click to expand...

I didn't know that's how it worked. Thanks for the explanation.
 
PlasticCigar said:
Mountain high sells a really nice pulse demand oxygen system. You can set it to automatically go on at 5000’, then it shuts off below 5000’. My built/in oxygen tank lasts about a year with this system.
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The Mountain High system is quite amazing. I have an E size bottle in my glider I have flown about 35 hours this spring mostly between 5000-12000 feet. I have been using the 5000 ft setting and even tried some of the higher flow settings. I have still used less than 700lbs out of the bottle.

Next week i will be doing a bunch of flights between 10000-18000 feet, I am sure the consumption rate will go up at these altitudes, As I recall the e bottle filled to 1600lbs usually lasts me something like 15-20 hours at these altitudes. A big improvement over me old continuous flow system, even with the oximizer cannula.

Brian
CFIIG/ASEL
 
SoCal RV Flyer said:
Interesting! Are those living at higher altitudes producing more red blood cells as well?
Click to expand...

Not necessarily. BPG just makes what you have more efficient at altitude. If you were born with a genetically predisposed high hematocrit then all the better, and you can transport more oxygen per unit volume. The cycling cheaters increased their hematocrit by injecting powerful hormones to stimulate blood cell production.
 
chemgeek said:
Those of you that live at higher altitudes have higher levels of 2,3-bisphosphoglycerate (2,3-BPG), a molecule that LOWERS the O2 affinity of hemoglobin. I know that sounds counter-intuitive, but lowering O2 affinity of hemoglobin allows it to release more of its O2 load in peripheral tissues. The binding curve of hemoglobin is sigmoidal, not linear or hyperbolic, with pressure. Hemoglobin in the presence of 2,3-BPG still saturates fairly well at the partial O2 pressures in the lungs, even at moderate altitudes typical of GA, but is dramatically better at dropping its load of oxygen in the peripheral tissues, where the partial O2 pressure is very low.

Anyone who stays at altitude for 2-3 weeks will start to benefit from higher 2,3-BPG levels, but the effect will slowly diminish when you go back to the lowlands as your 2,3-BPG levels gradually return to their former concentration. This temporary effect is why long distance runners train at high altitude for an extra edge when competing at a lower altitude.

Biochemistry is amazing stuff...
Click to expand...


Thanks @chemgeek for correcting my error.
That will teach me to try and write about physiology after a week of leave! #embarassed
 
Mike Blackburn said:
Thanks @chemgeek for correcting my error.
That will teach me to try and write about physiology after a week of leave! #embarassed
Click to expand...

No worries! I worked this topic hard with my foundational biochem students every year when we studied model allosteric proteins. #retiredchemprof
 
Somedudeintn said:
I’ve done a few flights at 10.5 and 11.5 at night and never checked my SpO2 levels. I picked up a pulse oximeter and would see 95-98% on the ground. I took a 4.5 hour flight each way this weekend (my longest flight yet) and flew at 8000 there and 9000 back.

I was surprised to see a lower SpO2 number even at those altitudes. The lowest I saw was 84, and was typically 88-94. I was able to get to 95 by focusing on breathing more deeply after I noticed a lower number. I’m in my mid thirties and exercise about once a week.

Anyway this is my Psa that I was surprised by lower numbers even below 10,000. I bought an E size O2 tank with a regulator and cannulas and masks off craigslist for $35 and plan on getting it filled at the airport tomorrow for $25.

I’m going to start planning on having O2 available for me on flights above 8000ft. I’m excited about some more options for flying higher too.

Anyway the PSA is to pick up a pulse oximeter and check your O2 saturation at altitude. You may be surprised.
Click to expand...

Flying at night above 8K without O2 not a great idea.
 
Clip4 said:
Flying at night above 8K without O2 not a great idea.
Click to expand...

When I grew up at 7,000' we would drive over the 9,000' pass at night all time time without O2. Driving is certainly more intensive than flying in most cases.
 
DesertNomad said:
When I grew up at 7,000' we would drive over the 9,000' pass at night all time time without O2. Driving is certainly more intensive than flying in most cases.
Click to expand...

It's a physiological night vision issue. And it you think you need better vision to drive in two dimensional space at night compared to flying (and landing) in three dimensional space at night, I might gently disagree.
 
So I stopped by at the FBO and they did not have anything to fill the CGA870 valve on my tank. I’m going to stop by the local gas shops in person next week and see if I can do better than them just telling me they can’t fill the med bottles without a RX. If that doesn’t work I’ll either buy the 870 to 540 adaptor or schedule my yearly checkup and see if my doc will write me an rx for O2 use at high altitudes.
 
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