Pulse oxymeter use

[John McLaughlin]

I've searched this forum and google, but can't find the information - can
anyone tell me what readings I should expect to see at altitude?
Presumably, a steady decrease from the ground level reading, despite using

supplemental oxygen? But without a table of what's normal for each
altitude, how can you know when you need to be descending?

[Bruce Hoult]

On Thursday, October 3, 2019 at 9:45:05 PM UTC+13, John McLaughlin wrote:
> I've searched this forum and google, but can't find the information - can
> anyone tell me what readings I should expect to see at altitude?
> Presumably, a steady decrease from the ground level reading, despite using
>
> supplemental oxygen? But without a table of what's normal for each
> altitude, how can you know when you need to be descending?

I believe the idea of supplemental oxygen is to keep within five points of your normal reading at sea level, and certainly no lower than 90.

I bought a unit a couple of weeks ago. I haven't used it in a glider yet, but today I spent 12 hours at 8000 ft pressure (presumably) in a B777. I dropped to 92-93 instead of my normal 96-97.

[Dan Daly[_2_]]

On Thursday, October 3, 2019 at 4:45:05 AM UTC-4, John McLaughlin wrote:
> I've searched this forum and google, but can't find the information - can
> anyone tell me what readings I should expect to see at altitude?
> Presumably, a steady decrease from the ground level reading, despite using
>
> supplemental oxygen? But without a table of what's normal for each
> altitude, how can you know when you need to be descending?

You should also see an increase in pulse as you climb.

[Mike Clarke]

At 09:06 03 October 2019, Bruce Hoult wrote:
>On Thursday, October 3, 2019 at 9:45:05 PM UTC+13, John
McLaughlin wrote:
>> I've searched this forum and google, but can't find the
information - can
>
>> anyone tell me what readings I should expect to see at altitude?
>> Presumably, a steady decrease from the ground level reading,
despite
>using
>>
>> supplemental oxygen? But without a table of what's normal for
each
>> altitude, how can you know when you need to be descending?
>
>I believe the idea of supplemental oxygen is to keep within five
points of
>your normal reading at sea level, and certainly no lower than 90.
>
>I bought a unit a couple of weeks ago. I haven't used it in a glider
yet,
>but today I spent 12 hours at 8000 ft pressure (presumably) in a
B777. I
>dropped to 92-93 instead of my normal 96-97.

Supplementary oxygen should maintain your normal reading of
around 96-97 up to the altitude where your oxygen system starts to
be unable to keep up. That altitude will depend on a number of
factors.

For anyone with a personal interest in survival while flying gliders at
altitude, I cannot recommend too highly the book by Jean-Marie
Clement "Dancing with the wind" which has 40 pages on "Oxygen:
basic physiological aspects, applied research, and management of
EDS". This chapter was written in collaboration with a qualified
medical expert and glider pilot, who in turn had carried out practical
research with the founder of Mountain High. This chapter alone is
worth the price of the book for serious high-altitude glider pilots.

It has interesting things to say about the FAA regulations:

"When the reader has finished this chapter, it will be tempting to
conclude that these aviation regulations are most generous, but the
most likely to result in accidents".

The chapter on "Health, altitude and long flights" is also very
informative. And the pictures throughout are amazing.

Mike

[[email protected]]

Here's another gem from NASA back in the 70's. Lots of answers for what happens if you do strange things to humans.

For O2, the charts on pages 39 and 41 are interesting.

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19730006364.pdf

Or Google NASA SP-3006
Bioastronautics Data Book

(There are interesting things at yard sales here ;-)

[Muttley]

On Thursday, October 3, 2019 at 9:45:05 AM UTC+1, John McLaughlin wrote:
> I've searched this forum and google, but can't find the information - can
> anyone tell me what readings I should expect to see at altitude?
> Presumably, a steady decrease from the ground level reading, despite using
>
> supplemental oxygen? But without a table of what's normal for each
> altitude, how can you know when you need to be descending?

Here is an article which appeared some time ago in the Soaring Magazine

https://1drv.ms/b/s!AgdlgPN7f_vjtxeDhiWV1ohboBQ9

[Tango Eight]

On Thursday, October 3, 2019 at 4:45:05 AM UTC-4, John McLaughlin wrote:
> I've searched this forum and google, but can't find the information - can
> anyone tell me what readings I should expect to see at altitude?
> Presumably, a steady decrease from the ground level reading, despite using
>
> supplemental oxygen? But without a table of what's normal for each
> altitude, how can you know when you need to be descending?

I was able to maintain 96 - 98% to 31,000 on my system (constant flow, with a good re-breather mask).

If you can't maintain 92% or higher, then something isn't right and needs to be corrected. Most people function at/near normal mental acuity at 92%.

When things aren't right, I've seen ox saturation go into low 80s. In the low 80s you will be seriously impaired and you need to correct your problem right away.

Chapter 1 for basic high altitude oxygen physiology
http://www.operationalmedicine.org/TextbookFiles/FlightSurgeonsManual.pdf

Side note: the armed services use way better equipment and procedures than we do, and the typical military aviator is young, and healthy and getting closely examined with regularity and deep suspicion. They don't use nasal cannulas for anything and they don't try to economize.

I agree with Jean Marie Clement (Dancing with the Wind): the regs are anti-conservative.

At 14,000 without ox, you will probably find that your saturation is really bad.

T8