$200 pulse oximeter for monitoring your oxygen saturation

COLIN LAMB wrote:

Question - will the reading of the pulse oximeter discriminate against
carbon monoxide?

In other words, does the use of a pulse oximeter reduce the need of a carbon
monoxide detector? If carbon monoxide replaces oxygen, then the % of oxygen
would decrease and the oximeter would drop substantially when carbon
monoxide is present? Right?

I've never seen anything discussing the issue at all, so I'm guessing it
doesn't (not so much an issue for my ASH 26 E). Jim Skydell had an
article in Soaring about oximeters earlier, so you might check with him.
He's much more knowledgeable about them than I am.


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Eric Greenwell
Washington State
USA

The best thing when wave flying is to breath oxygen for a hour before the
flight or going above 8000 ft thus saturating your body with oxygen.

Great flight Mal! I'd love to have a wave flight like that sometime.

However, your body only has a tenuous ability to "store" oxygen, and that is
when it is bound to hemoglobin in your red blood cells. Given that your
cardiac output is about 5 liters/min and your blood volume is about 10
liters you can, theoretically, "saturate" your oxygen stores in about 2
minutes. Furthermore, if you are breathing normally, don't have pulmonary
disease, and are not launching from a significant altitude, your blood is
already leaving your lungs very nearly oxygen saturated. What I am saying is
that it is not nescessary to go on oxygen an hour before a wave flight
because you can't store oxygen or "saturate your body" - do you think being
on 100% oxygen for an hour would allow you to hold your breath significantly
longer?.

As we all know, blood oxygenation levels can change very quickly with the
limiting factors for a healthy pilot being partial pressure of oxygen in the
lung (altitude) and type of breathing (normal full breath vs shallow
breathing vs hyperventilating). This is why a pulse-ox meter can be so
valuable, you may have a false sense of security if you are breathing 100%
O2 but your respiratory rate and depth is slow and shallow resulting in a
surprising hypoxia.

Just stuff to think about. My real pet peave is athletes rushing to the
sideline to get their O2 fix, the trainers or sports docs providing that
must have flunked physiology.

Tim

Mal wrote:

http://www.craggyaero.com/Oxygen.htm

Looks smaller at flight level 240 it was minus 24 C and I had gloves on it
was bloody cold I do not think I would take the gloves or glove off to see
my saturation.

The best thing when wave flying is to breath oxygen for a hour before the
flight or going above 8000 ft thus saturating your body with oxygen.

It worked for me http://www.mals.net/bunyan04/pages/Picture%20001.htm

My understanding is pre-breathing is mainly to reduce the nitrogen
levels in your blood, not increase the oxygen. It does help a lot of
pilots to turn on the oxygen early on the way up, to compensate for
reduced lung function due to age, smoking, and other factors. Some
pilots don't get full saturation just standing on the ground!

An oximeter will let you determine this, and perhaps alert you to
inadequate oxygen in flight, whether due to those factors already
mentioned, or equipment problems like a leak, kinked hose, bad
regulator, low pressure in the bottle, and so on.


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Eric Greenwell
Washington State
USA

"Eric Greenwell" wrote in message
...

Which unit are you using, and which unit do you wish you had? I've seen
the Minolta Pulsox-3, which looks ideal except for costing 2.5 times as
much.

I've been using the Palco Labs "Aero" for the last 5 years and I wouldn't
change.

Bill Daniels

On Thu, 11 Nov 2004 04:38:35 GMT, Tim Traynor wrote:

The best thing when wave flying is to breath oxygen for a hour before the
flight or going above 8000 ft thus saturating your body with oxygen.

Great flight Mal! I'd love to have a wave flight like that sometime.

However, your body only has a tenuous ability to "store" oxygen, and that is
when it is bound to hemoglobin in your red blood cells. Given that your
cardiac output is about 5 liters/min and your blood volume is about 10
liters you can, theoretically, "saturate" your oxygen stores in about 2
minutes. Furthermore, if you are breathing normally, don't have pulmonary
disease, and are not launching from a significant altitude, your blood is
already leaving your lungs very nearly oxygen saturated. What I am saying is
that it is not nescessary to go on oxygen an hour before a wave flight
because you can't store oxygen or "saturate your body" - do you think being
on 100% oxygen for an hour would allow you to hold your breath significantly
longer?.

As we all know, blood oxygenation levels can change very quickly with the
limiting factors for a healthy pilot being partial pressure of oxygen in the
lung (altitude) and type of breathing (normal full breath vs shallow
breathing vs hyperventilating). This is why a pulse-ox meter can be so
valuable, you may have a false sense of security if you are breathing 100%
O2 but your respiratory rate and depth is slow and shallow resulting in a
surprising hypoxia.

Just stuff to think about. My real pet peave is athletes rushing to the
sideline to get their O2 fix, the trainers or sports docs providing that
must have flunked physiology.

Tim

Tim,
We were taught during an altitude chamber run with the RAAF (Ozzie
Airforce), that breathing 100% Ox for a while before going to a lower
pressure environment reduces the amount of dissolved nitrogen in your
blood, so makes it less likely you will suffer "the bends" at high
altitude.
No mention was made of "being able to store the oxygen for future
use", and I agree with you on this aspect of the discussion.
Maybe some people have heard about the 100% Ox breathing for a half
hour from people who have done a chamber run, but have not understood
the reason for the pre-exposure.
Cheers, John G.

COLIN LAMB wrote:

Question - will the reading of the pulse oximeter discriminate against
carbon monoxide?

Great question Colin. The answer is NO. I had to look it up (from an article in the
medical literature by Neil B. Hampson):

"Presently available pulse oximeters overestimate arterial oxygenation in patients with
severe CO [carbon monoxide] poisoning. An elevated COHb [carbon monoxide bound to
hemoglobin] level falsely elevates the [level of oxygen in the blood] as measured [by]
pulse oximetry, (CHEST 1998; 114:1036-1041)"

What this means is that carbon monoxide, when attached to a hemoglobin molecule (which
carries oxygen within red blood cells) fools pulse oximeters into thinking there is more
oxygen in the blood than there really is. This is not surprising, since oximetry
basically does an analysis of blood color (the redder the blood, the more oxygen it
should be carrying). One way to guess that a patient has carbon monoxide poisoning is
that their skin and lips frequently look very red.

In other words, does the use of a pulse oximeter reduce the need of a carbon
monoxide detector? If carbon monoxide replaces oxygen, then the % of oxygen
would decrease and the oximeter would drop substantially when carbon
monoxide is present? Right?

Wrong. Although carbon monoxide does replace oxygen on the hemoglobin molecule, it fools
the oximeter in thinking there is more oxygen, when there really is less.

Regards,
Jim Skydell

"John Giddy" wrote in message
...
On Thu, 11 Nov 2004 04:38:35 GMT, Tim Traynor wrote:

The best thing when wave flying is to breath oxygen for a hour before
the
flight or going above 8000 ft thus saturating your body with oxygen.

Great flight Mal! I'd love to have a wave flight like that sometime.

However, your body only has a tenuous ability to "store" oxygen, and that
is
when it is bound to hemoglobin in your red blood cells. Given that your
cardiac output is about 5 liters/min and your blood volume is about 10
liters you can, theoretically, "saturate" your oxygen stores in about 2
minutes. Furthermore, if you are breathing normally, don't have pulmonary
disease, and are not launching from a significant altitude, your blood is
already leaving your lungs very nearly oxygen saturated. What I am saying
is
that it is not nescessary to go on oxygen an hour before a wave flight
because you can't store oxygen or "saturate your body" - do you think
being
on 100% oxygen for an hour would allow you to hold your breath
significantly
longer?.

As we all know, blood oxygenation levels can change very quickly with the
limiting factors for a healthy pilot being partial pressure of oxygen in
the
lung (altitude) and type of breathing (normal full breath vs shallow
breathing vs hyperventilating). This is why a pulse-ox meter can be so
valuable, you may have a false sense of security if you are breathing
100%
O2 but your respiratory rate and depth is slow and shallow resulting in a
surprising hypoxia.

Just stuff to think about. My real pet peave is athletes rushing to the
sideline to get their O2 fix, the trainers or sports docs providing that
must have flunked physiology.

Tim

Tim,
We were taught during an altitude chamber run with the RAAF (Ozzie
Airforce), that breathing 100% Ox for a while before going to a lower
pressure environment reduces the amount of dissolved nitrogen in your
blood, so makes it less likely you will suffer "the bends" at high
altitude.
No mention was made of "being able to store the oxygen for future
use", and I agree with you on this aspect of the discussion.
Maybe some people have heard about the 100% Ox breathing for a half
hour from people who have done a chamber run, but have not understood
the reason for the pre-exposure.
Cheers, John G.

John and Eric are right about pre-breathing preventing decompression
sickness (precipitation of N2 in fluids and joints due to decreased
solubility at altitude) but it does not prevent hypoxia, this is an
important distinction and one I left out of my discussion. I have heard
pilots mention using pre-breathing as a method to prevent hypoxia and I have
worried that such a pilot may not be as diligent in hypoxia monitoring if
they feel pre-breathing will protect them. This is what I infered with Mal's
statement.

Tim

Bill Daniels wrote:

"Eric Greenwell" wrote in message
...


Which unit are you using, and which unit do you wish you had? I've seen
the Minolta Pulsox-3, which looks ideal except for costing 2.5 times as
much.


I've been using the Palco Labs "Aero" for the last 5 years and I wouldn't
change.

Why do you prefer this to the Minolta unit?


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Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

"COLIN LAMB" wrote in message
hlink.net...
Question - will the reading of the pulse oximeter discriminate against
carbon monoxide?

In other words, does the use of a pulse oximeter reduce the need of a
carbon
monoxide detector? If carbon monoxide replaces oxygen, then the % of
oxygen
would decrease and the oximeter would drop substantially when carbon
monoxide is present? Right?

Colin N12HS


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Pulse oximetry cannot distinguish between different forms of haemoglobin.
Carbo-xyhaemoglobin (haemoglobin combined with carbon monoxide) is
registered as 90% oxygenated haemoglobin and 10% desaturated haemoglobin -
therefore the oximeter will overestimate the saturation. The presence of
methaemoglobin will prevent the oximeter working accurately and the readings
will tend towards 85%, regardless of the true saturation.

So the answer to your question is - you still need a CO monitor if there's
an engine about.

Ian

"Eric Greenwell" wrote in message
...
Bill Daniels wrote:

Pulse oxymeters need warm fingers with a good blood flow to get a
reading.
Clip on units like this require that you remove a glove to use it - not a
good idea in a wave. I'd pass.


I use a Nonin earlobe clip on a flylead connected to a panel mounted unit.
The sensor can be worn under a hat or balaclava so the sensor and my ears
stay warm. Less interference with controls and can 'fit and forget' for the
whole flight.

Ian