Hypoxia, driving up pike's peak
Don Elton
In-Reply-To: plu...@altamira.theme.com (William W. Plummer)
Organization: ProLine [pro-carolina] Orlando, Florida 407-858-9937
It wouldn't be the greatest thing to do. Driving (and particularly if
staying near the top) could get you mountain sickness (which isn't a
problem with pilots since we don't have enough fuel to stay at altitude
long enough to get it in most cases) and the hypoxic challenge wouldn't be
for everyone, particularly trying to drive in that condition. At around
14,000 feet, your oxygen level would be a hemoglobin saturation ranging
from 70-85% depending on how much you hyperventilated in response to the
hypoxia. Again this would be a poor place to discover that you had
coronary or cerebrovascular disease. This doesn't mean people can't
survive the behavior but it's not without its risks either.
Don Elton
ProLine: delton@pro-carolina GEnie, MCI, AOL: delton
Internet: del...@pro-carolina.oau.org CIS: 72010,37
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Lisa Corsetti
: In-Reply-To: plu...@altamira.theme.com (William W. Plummer)
: Organization: ProLine [pro-carolina] Orlando, Florida 407-858-9937
: It wouldn't be the greatest thing to do. Driving (and particularly if
: staying near the top) could get you mountain sickness (which isn't a
I can speak from personal experience on this. When I was 18, my family
visited Pike's Peak and we took the "cog railway" to the top - a *much*
better idea than driving. Within about 15 minutes of reaching the top,
I began to feel very ill. Everyone else said I was "turning green".
Unfortunately, I couldn't ask for a lower altitude.
Wallace Venable
Mountain high altitude driving also carries some risk, but when
driving up Pikes Peak to 14,000, most people will have at least somewhat
aclimatized to the base elevation of about 5,000.
A pilot can take off from, say Death Valley, below sea level, and
climb to 12,500 or more in one hour.
The other issue is the mental demands of flying a complex
route versus driving up and down a single road lane.
Don Elton
which acclimization of less than at least a few months is of little help.
Rate of arrival isn't very important for this either. The other risk is
mountain sickness and high altitude pulmonary edema. These are helped by a
few hours of life at an intermediate altitude but individual
susceptibilities vary and are sometimes difficult to predict. HAPE and
mountain sickness aren't an issue for pilots as you usually need 6 or more
hours at the high altitude (many times 12 hours) and most of our planes
don't have that sort of endurance.
Jordan Brown
>At around 14,000 feet, your oxygen level would be a hemoglobin saturation
>ranging from 70-85% depending on how much you hyperventilated in response
>to the hypoxia.
Hmm? I'm under the impression, both from what I've read and from personal
experience, that hypoxia doesn't cause hyperventilation. The breathing
reflex is controlled by excess CO2, not by a lack of O2.
Are you talking about intentional hyperventilation? (Does intentional
hyperventilation help the O2 picture?)
I don't know why people tend to breathe hard during exercise at altitude.
I do know that sitting at 25K I felt no urge to breathe hard, and that
I did not observe anybody in the chamber breathing hard.
Don Elton
ventilation is controlled by CO2 levels but when your oxygen levels fall
there is a secondary response to involuntarily hyperventilate. It is not
necessarily apparent to an observer, or even the patient him or herself
that hyperventilation is occuring but if a blood gas study is drawn the CO2
level will lower once the PO2 level falls much below 70 or so. There is no
way to prevent this even if you try. The hyperventilation response
automatically allows you to go a little higher than you'd be able to
survive otherwise. Every person in the chamber with you including yourself
was probably hyperventilating and would be apparent if blood gasses were
drawn. "Breathing hard" and hyperventilation are two separate entities. On
average, a person with normal lungs will at least double their minute
breathing volume given an altitude challenge and most will not be aware
that they've done it.
Dave Allen
del...@pro-carolina.oau.org (Don Elton) writes:
>The hyperventilation response
> automatically allows you to go a little higher than you'd be able to
> survive otherwise.
Wow. I thought hyperventilation was always bad - reduced the absorption of
oxygen into the blood. Or wait - it's bad under normal circumstances because
it gets you too much O2 and that makes you sick?
> "Breathing hard" and hyperventilation are two separate entities. On
> average, a person with normal lungs will at least double their minute
> breathing volume given an altitude challenge and most will not be aware
> that they've done it.
Wow again. Expand on the differences between breathing hard and hyperv.
Hyperv is quick and shallow? Isn't deep breathing best for O2 exchange?
Does "double their minute breathing volume" mean an increase in respiration
rate? Could we monitor respiration rate as a sign that we are getting
"altitude challenged"? Granted, we "adjust" our respiration rate when it's
being monitored. :-(
dave allen - Fly because you love it.
PS: alfred!MAILER...@osceola.cs.ucf.edu wrote back (tho it was
"From: MAILER...@alfred.oau.org") and said
"del...@pro-carolina.oau.org ... unknown host".
I can send you all the details if you need them.
Don Elton
of gas moved per minute) is in excess of that necessary to give you a
normal blood CO2 level. You can hyperventilate by increasing your rate of
breathing, your depth of breathing, or some combination of the two. Normal
people can at least double their minute volume hardly being aware that
they've done so so it's not really breathing hard per se.
Breathing hard implies that you are reaching the limits of your ability to
increase your minute volume. This is what happens when you exercise and
your body has greatly increased its metabolism and hence its level of CO2
production. You may be breathing hard in this circumstance but if your
level of breathing is only appropriate to the amount of CO2 produced by
metabolism then you won't be hyperventilating even though your minute
volume may well be increased. Thus, hyperventilation is purely a
comparison of your minute volume to your CO2 production.
Hyperventilation syndrome is the thing the FAA talks about in their
circulars. This means you are hyperventilating, usually due to anxiety,
and your CO2 levels fall enough to give you symptoms (like chest pain,
shortness of breath, and numbness in your hands and feet) that increase the
anxiety level and make the syndrome worse. This has nothing to do with the
sort of natural/automatic hyperventilation that occurs with any hypoxic
challenge. Hyperventilation syndrome is most commonly seen in teen age
girls who've been stood up for a date and it accounts for lots of ER visits
for chest pain in 15 year old girls but isn't that common in adults.
Gene McCullough
feet:
About 1 out of every 2 or 3 summers I have worked in the high altitude
research facility which the U.S. Army runs on the summit of Pikes Peak.
Several 100,000 people drive the Pikes Peak road or ascend via the cog
railway each summer, and there are very few deaths. Still there are a LOT
of goofy people staggering around up there - I'd like to think that they
aren't that goofy at lower altitudes. Personally, having done (maybe
"tried to do" would be better) "serious" work at that altitude, I realize
that 14,000 ft is not the environment for "serious" thinking - like
piloting an airplane. For that matter the hypoxia experienced in Leadville
CO at 10,200 ft is noticable.
Gene McCullough
Univ. of Colorado Health Sciences Center
Denver, CO
mccull...@defiance.hsc.colorado.edu