Flight Oximeter and 02 Saturation Standards

On Mon, 12 Jan 2004 04:10:22 GMT, Dave S wrote:

Holy ****....

Yanno... blood RETURNING to the lungs, after its been used, has
saturations in mid to low 70's.. We start getting worried when the mixed
venous sat's stay (despite treatment) in the 60's.. (on the really sick
ICU patients, particularly Trauma and Cardiac Surgery ones, we place a
catheter to follow those values, in addition to others)

If your arterial sat is in the 70's you are not doing yourself any
favors at all.

Dave, RN, EMTP, PPASEL

Don't forget that in acclimated folk, the O2-Hgb dissociation curve is
shifted to the right. So at the same atmospheric pO2, they will have a
lower blood O2 saturation and a higher level of tissue oxygenation then
unacclimated folk. Very different from sick or post-op patients.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

I suppose that we should start a drive to shut down most of the CO ski
resorts? Many people arriving from sea level will have 02 saturations in the
70s at the top of Vail or Aspen.

None of the anesthesiologists that are climbers (and there seem to be a lot
of them for some reason) seem to think it is a big deal.
Seriously, there is probably a difference between healthy people with low O2
saturation at high altitude and sick people.

Mike
MU-2

"Dave S" wrote in message
nk.net...
Holy ****....

Yanno... blood RETURNING to the lungs, after its been used, has
saturations in mid to low 70's.. We start getting worried when the mixed
venous sat's stay (despite treatment) in the 60's.. (on the really sick
ICU patients, particularly Trauma and Cardiac Surgery ones, we place a
catheter to follow those values, in addition to others)

If your arterial sat is in the 70's you are not doing yourself any
favors at all.

Dave, RN, EMTP, PPASEL

Mike Rapoport wrote:

Depends on who you are, what you do and where you live. If you are an
athlete living in Frisco, CO (10,000"), 12,500 is trivial. Then there
are
the people who get High Altitude Pulminary Edema on a bus from San
Francisco
to Reno. You can choose to use O2 at sea level if you choose but lets
not
make it apply to everybody.

We had an oximeter the last time I went climbing and the results were
interesting. Upon reaching each new altitude, O2 levels were in the mid
80s
but a day or two later they were in the low to mid 90s. This pattern
continued to over 17,000' where we stopped taking measurments. Looking
back, you could have predicted who would drop out several days before
they
actually did. Those who had readings in the 70s upon arrival and low
80s a
day later dropped out 3,000' higher where their readings were in the
60s.

Mike
MU-2

"O. Sami Saydjari" wrote in message
...

Ross, Excellent articles. Thanks so much for pointing them out. I
particularly enjoyed the part about focused breathing yeilding a
significantly improved oxygen saturation.

I know it has been pointed out in several different places, but it seems
pretty clear that the FAA needs to reconsider its supplemental oxygen
requirements. Waiting until 12,500 seems like a bad idea.

-Sami

Ross Oliver wrote:

Every pilot should definitely read these two articles:

Review of Nonin Onyx Pulse Oximeter
(has good info that would probably apply to all brands of oximeters)
http://www.aeromedix.com/aeromedix/art/pulseox/

Respiration: What Pilots Need to Know (But Aren't Taught)
http://www.aeromedix.com/aeromedix/a.../respirat.html

As with many regs, this one probably didn't even exist until someone bent
metal because they were careless. Adhering to the regs makes you legal but
not necessarily wise. If you think you need to use oxygen at a lower
altitude, then by all means do so. But making it a reg may not actually
change anything, an example...

Every time I take a checkride, the DE spends about 5 minutes talking about
what it takes to be legal versus what makes you a safe pilot. On my last
checkride, she related that when she started flying, there was no minimum
fuel requirement (e.g. 45 minutes IFR reserves, etc) because the FAA assumed
pilots were smart enough to bring enough fuel and monitor the flow. The
requirement for reserves was added AFTER too many pilots ran out of fuel and
wrecked planes. Note, however, that even with the "new" regs pilots are
still running out of fuel at an embarrasing rate.

I think education is the key here, not more regs.

blue skies,
mark

"O. Sami Saydjari" wrote in message
...
Ross, Excellent articles. Thanks so much for pointing them out. I
particularly enjoyed the part about focused breathing yeilding a
significantly improved oxygen saturation.

I know it has been pointed out in several different places, but it seems
pretty clear that the FAA needs to reconsider its supplemental oxygen
requirements. Waiting until 12,500 seems like a bad idea.

-Sami

Ross Oliver wrote:
Every pilot should definitely read these two articles:

Review of Nonin Onyx Pulse Oximeter
(has good info that would probably apply to all brands of oximeters)
http://www.aeromedix.com/aeromedix/art/pulseox/

Respiration: What Pilots Need to Know (But Aren't Taught)
http://www.aeromedix.com/aeromedix/a.../respirat.html

I flew the plane I just bought back from Reno on 1/12/04. I flew back
at 17,000.

Just to get a baseline, I monitored my O2 level on the commercial flight
on the way to Reno to see what cabin pressure commercial jets do. My
normal saturation on the ground is 97%. At altitude (I thikn around
35,000) on a commercial jet with cabin pressure, it dropped to 92 (+/- 2).

Flying the Turbo Arrow III, I noticed O2 levels falling below 90 at
around 12,000. So, I went onto 02 at that point. Low flow rates were
quite adequate for the next few thousand feet. At 17,000, a flow of 2
liters per minute seemed very comfortable. With focused deep breathing,
we could easily get away with about 1/2 liter per minute...but it was
too difficult to maintain that sort of breathing for long...too
distracting. My co-pilot went off oxygen for 5 minutes as an
experiment. His 02 dropped to about 80. He definitely felt affected.

One thing I noticed is that two people breathing 2 lpm can consume quite
a lot of oxygen. A 40 Cu ft. bottle was 2/3 empty after 4 hours. We
used 02 masks. After that, I decided to get a conserving nasal canula.
They are supposed to use one fourth as much 02. Given the cost of
refills, that will be a big cost saver.

-Sami (Piper T-Arrow III N2057M)


Mark Astley wrote:
As with many regs, this one probably didn't even exist until someone bent
metal because they were careless. Adhering to the regs makes you legal but
not necessarily wise. If you think you need to use oxygen at a lower
altitude, then by all means do so. But making it a reg may not actually
change anything, an example...

Every time I take a checkride, the DE spends about 5 minutes talking about
what it takes to be legal versus what makes you a safe pilot. On my last
checkride, she related that when she started flying, there was no minimum
fuel requirement (e.g. 45 minutes IFR reserves, etc) because the FAA assumed
pilots were smart enough to bring enough fuel and monitor the flow. The
requirement for reserves was added AFTER too many pilots ran out of fuel and
wrecked planes. Note, however, that even with the "new" regs pilots are
still running out of fuel at an embarrasing rate.

I think education is the key here, not more regs.

blue skies,
mark

"O. Sami Saydjari" wrote in message
...

Ross, Excellent articles. Thanks so much for pointing them out. I
particularly enjoyed the part about focused breathing yeilding a
significantly improved oxygen saturation.

I know it has been pointed out in several different places, but it seems
pretty clear that the FAA needs to reconsider its supplemental oxygen
requirements. Waiting until 12,500 seems like a bad idea.

-Sami

Ross Oliver wrote:

Every pilot should definitely read these two articles:

Review of Nonin Onyx Pulse Oximeter
(has good info that would probably apply to all brands of oximeters)
http://www.aeromedix.com/aeromedix/art/pulseox/

Respiration: What Pilots Need to Know (But Aren't Taught)
http://www.aeromedix.com/aeromedix/a.../respirat.html

I had a pair of Mountain High EDS units which use about 1/4 as much O2 as
the Cannulas. Worked great! See
http://www.mhoxygen.com/

Mike
MU-2

"O. Sami Saydjari" wrote in message
...
I flew the plane I just bought back from Reno on 1/12/04. I flew back
at 17,000.

Just to get a baseline, I monitored my O2 level on the commercial flight
on the way to Reno to see what cabin pressure commercial jets do. My
normal saturation on the ground is 97%. At altitude (I thikn around
35,000) on a commercial jet with cabin pressure, it dropped to 92 (+/- 2).

Flying the Turbo Arrow III, I noticed O2 levels falling below 90 at
around 12,000. So, I went onto 02 at that point. Low flow rates were
quite adequate for the next few thousand feet. At 17,000, a flow of 2
liters per minute seemed very comfortable. With focused deep breathing,
we could easily get away with about 1/2 liter per minute...but it was
too difficult to maintain that sort of breathing for long...too
distracting. My co-pilot went off oxygen for 5 minutes as an
experiment. His 02 dropped to about 80. He definitely felt affected.

One thing I noticed is that two people breathing 2 lpm can consume quite
a lot of oxygen. A 40 Cu ft. bottle was 2/3 empty after 4 hours. We
used 02 masks. After that, I decided to get a conserving nasal canula.
They are supposed to use one fourth as much 02. Given the cost of
refills, that will be a big cost saver.

-Sami (Piper T-Arrow III N2057M)


Mark Astley wrote:
As with many regs, this one probably didn't even exist until someone
bent
metal because they were careless. Adhering to the regs makes you legal
but
not necessarily wise. If you think you need to use oxygen at a lower
altitude, then by all means do so. But making it a reg may not actually
change anything, an example...

Every time I take a checkride, the DE spends about 5 minutes talking
about
what it takes to be legal versus what makes you a safe pilot. On my
last
checkride, she related that when she started flying, there was no
minimum
fuel requirement (e.g. 45 minutes IFR reserves, etc) because the FAA
assumed
pilots were smart enough to bring enough fuel and monitor the flow. The
requirement for reserves was added AFTER too many pilots ran out of fuel
and
wrecked planes. Note, however, that even with the "new" regs pilots are
still running out of fuel at an embarrasing rate.

I think education is the key here, not more regs.

blue skies,
mark

"O. Sami Saydjari" wrote in message
...

Ross, Excellent articles. Thanks so much for pointing them out. I
particularly enjoyed the part about focused breathing yeilding a
significantly improved oxygen saturation.

I know it has been pointed out in several different places, but it seems
pretty clear that the FAA needs to reconsider its supplemental oxygen
requirements. Waiting until 12,500 seems like a bad idea.

-Sami

Ross Oliver wrote:

Every pilot should definitely read these two articles:

Review of Nonin Onyx Pulse Oximeter
(has good info that would probably apply to all brands of oximeters)
http://www.aeromedix.com/aeromedix/art/pulseox/

Respiration: What Pilots Need to Know (But Aren't Taught)
http://www.aeromedix.com/aeromedix/a.../respirat.html

At FL180, the partial pressure of Oxygen is 50% that at sea level.

In an otherwise healthy human being, the oxygen content (as measured as
a partial pressure of gas) of blood starts dropping off pretty abruptly
below 90-92% (Im omitting co-factors such as temperature, blood counts,
blood pH and such for non-medical people). In the in-hospital
population, we treat saturations below 92% in major medical
center/teaching hospital intensive care units that I work in, and below
90% in persons with SEVERE lung disease (again, Im keeping it simple for
the non-medical people).

I would avoid sats in the 80's as a general rule, if you are going to
titrate your oxygen flow based on a portable pulse ox. You will have
less fatigue, less headache, and less cardiovascular stress. You will
FEEL better.

If your sat is below 92% on the ground, without oxygen, I would
recommend talking to a doctor to find out why.

When I did flight nursing, we dealt with cabin altitudes of 5-7k feet
and it wasnt uncommon for patients to drop from 95% down to the high
80's.. as a result we routinely placed ALL of our patients on low flow
supplemental oxygen.. usually 2 liters per minute as a minimum, and gave
more as needed to keep the saturation up. Keep in mind, these are sick
people with little cardiovascular reserve, so we were minimizing patient
stressors that the healthy flight crew could readily tolerate. I have no
idea what the equivalent settings are on aviation oxygen systems - the
ones I have seen are labelled with altitudes rather than their
corresponding flow rates. But if you are using a pulse ox, adjust it
until you get the desired result.

As for "chamber rides" I dont have any resources on how to set that up.
I know that some NASA facilities can accomplish this, but I dont have
any contact info with regards to that.

Dave, PPASEL, RN/Paramedic

O. Sami Saydjari wrote:

I just bought a FlightStat Fingertip Pulse Oximeter as an added measure
of safety when flying at oxygen altitudes (with oxygen, obviously).
Anyway, the device does not really come with any guidelines on threshold
levels below which you should be concerned.

1. A little background reading suggests that 93% is good; 89% seems to
be OK, but the lowest one would want to go to avoid any imapirment.
Does anyone know definitive values?

2. Does anyone have experience with Oximeters like this? What values do
you see at the higher altiutudes (non-cabin pressure aircraft...just
supplemental oxygen).

3. I read that, at least at one time, one could find places (often
military bases) where pilots could go and experience O2 deprivation in a
controled environment to learn about its effects and how better to
notice them. Does anyone know where on goes to try this out and how one
finds the nearest place to do this. Seems like a good safety exercise.