Postings being removed?

BlankI hate to sound paranoid, but I had put on a posting asking for
information on oxygen systems. It disappeared after several days. I
reposted - same thing - was gone several days later. I then posted what I
thought was a nice bit of information and suggested preflight for the D1 -
same thing - gone after several days.

Frankly I was unaware that anyone could - either technically or ethically -
erase someone else's post. Maybe this isn't what is happening, if so -
anyone have any idea what is? The messages were in HTML - should this make
any difference?

David Reed M.D., Boulder CO

I have just found and re-read three of your postings:

12 May - D1 info and preflight.

5 & 9 May - Need oxygen information.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.


"Neptune" wrote in message
...

BlankI hate to sound paranoid, but I had put on a posting asking for
information on oxygen systems. It disappeared after several days. I
reposted - same thing - was gone several days later. I then posted what I
thought was a nice bit of information and suggested preflight for the D1 -
same thing - gone after several days.

Frankly I was unaware that anyone could - either technically or
ethically - erase someone else's post. Maybe this isn't what is
happening, if so - anyone have any idea what is? The messages were in
HTML - should this make any difference?

David Reed M.D., Boulder CO

I cut and pasted it-use google to find your postings.


I apologize for starting this thread again - it somehow
vanished...

To those of you who left helpful messages - thanks.

My interest in this are is not limited to soaring flight
- the powered boys
have (in my opinion) the same potential problem and
perhaps moreso in that
they can carry more passengers.

I apologize for being listed as 'Neptune' - something
I must have set this
up way back when and don't remember how to change it.
I am - in real life -
David Reed M.D. from Boulder, CO

My concerns with oxygen utilization are as follows:

1. Presently the FAA mandates for oxygen flow rates
at altitude are found
in 14CFR23.1443. They are based on tracheal oxygen
saturation measurements -
a technique that has been superseded by arterial blood
gas measurements and
now pulse oximetry. These same mandates date back to
the old (at least 40
year-old!) CAA mandates.

2. There appear to be no peer-reviewed published studies
- either in flight
or an altitude chamber - that validate these flow rates.

3. I do have some flight data from the one company
that was willing to
release the data as long as I did not mention the company
name. 6-subject
in-flight with an A-4. A 'regular' nasal cannula was
tested, then repeated
with an Oxymizer at each nominated altitude. Results:

13M - FAA flow rate 0.86LPM - saturations of 87-97%
14M - 0.98
88-98%
15M - 1.10
87-97%
16M - 1.22
85-97%
17M - 1.34
86-95%
18M - 1.46
78-94%

There was no significant difference in use of the
Oxymizer.

As most of us physicians will agree - at around
90% saturation we begin
to get concerned. The above data indicate to me that
at the FAA flow rates
that were extrapolated from the 1443 graph some individuals
were clinically
hypoxic - a condition not changed by using the Oxymizer.
Am I coming up with
a solution without a problem as someone has suggested?
Not if a pilot can
saturate at 78%...

3. 1443 mandates flow rates for continuous flow systems.
Newer systems
utilize 'pulsed' flows. Manufacturers claim greatly
reduced oxygen
utilization using these systems, and even lesser use
when these 'pulsed'
systems are used with an Oxymizer type of cannula.
As far as I can tell
these claims have never been objectively and openly
verified by any
peer-reviewed research.

4. There does not appear to be any FAA requirement
that oxygen delivery
systems claims such as those above be independently
verified.

I am not at all saying that these performance claims
are wrong. All I would
like to see is some FAA mandate that oxygen delivery
systems should be
objectively tested for compliance with pulse-oximetry
values of over 90% at
all altitudes at which they will be used. At this point
all I can say as I
put on my system is that is SHOULD be OK - and if I
have (and use) a pulse
ox I SHOULD be OK.

I agree - a pulse ox should solve the problem - but
how many of us have/use
one? Sure we should - but out in the 'real world'?
Not very likely. In a
four-place 210 at FL240 are all people including passengers
going to be
using a pulse ox? My friend in the back seat? Will
I own two pulse ox - one
for me and one for the for the guy in back?

So - it would be nice to know that a system one uses
will keep a pilot (or
passenger) from getting hypoxic even if a pulse ox
isn't used. It appears
that, company claims to the contrary, the A4 does not
do this. This (in my
opinion) is not the fault of the A4 - it simply was
manufactured IAW 40
year-old obsolete 1443 flow rates. The new 'pulsed'
systems have no mandates
at all - at least as far as I can tell. I may be wrong
- if so please let me
know.

The research should not be hard to do. Perhaps someone
out there has some
data that could be of interest. The FAA has no funds
for this so I am trying
to find a university/altitude chamber that would be
interested in some
studies.

Any comments (at least any helpful and non-sarcastic
ones) would be
appreciated.

David Reed M.D., Boulder, CO (presently living in New
Zealand until end
May).








At 22:06 17 May 2004, Neptune wrote:
BlankI hate to sound paranoid, but I had put on a posting
asking for
information on oxygen systems. It disappeared after
several days. I
reposted - same thing - was gone several days later.
I then posted what I
thought was a nice bit of information and suggested
preflight for the D1 -
same thing - gone after several days.

Frankly I was unaware that anyone could - either technically
or ethically -
erase someone else's post. Maybe this isn't what is
happening, if so -
anyone have any idea what is? The messages were in
HTML - should this make
any difference?

David Reed M.D., Boulder CO

"Neptune" wrote in message
...
BlankI hate to sound paranoid, but I had put on a posting asking for
information on oxygen systems. It disappeared after several days. I
reposted - same thing - was gone several days later. I then posted what I
thought was a nice bit of information and suggested preflight for the D1 -
same thing - gone after several days.

Frankly I was unaware that anyone could - either technically or ethically -
erase someone else's post. Maybe this isn't what is happening, if so -
anyone have any idea what is? The messages were in HTML - should this make
any difference?

David,

First; as others have noted, your posts are still there. For some reason,
perhaps because of the settings in your own computer or because of the
particular news server you use, you can't see them.

Second; why don't you better define your basic concern? Are you concerned
about preventing oxygen-related aircraft accidents (not a large category of
aircraft accidents) or is there a possibility of cumulative physiological damage
from years of flying with inadequate oxygen? Or, (and this is OK too) is your
interest in this subject purely academic?

Is there really one oxygen flow rate that is optimum for all humans? I
doubt it. It seems to me that the only truly "safe" oxygen system would be one
that is individually, continuously and automatically regulated by pulse
oxymetry; but that same system might actually be unsafe compared to the 1960's
technology because of the opportunities for failure.

As simple and cheap as pulse oxymetry has become, perhaps what we really
need is a simple monitoring and ALARM unit designed for cockpit use. I happen
to have a Nonin Flitestat but find that it has severe limitations in the
cockpit.


Vaughn



David Reed M.D., Boulder CO

"Vaughn" wrote in message
...
Trimmed ....
As simple and cheap as pulse oxymetry has become, perhaps what we
really
need is a simple monitoring and ALARM unit designed for cockpit use. I
happen
to have a Nonin Flitestat but find that it has severe limitations in the
cockpit.


Vaughn

I'd be interested in your opinions on why there are 'severe limitations in
the cockpit '. Could you please elaborate Vaughn

Ian

"tango4" wrote in message
...

"Vaughn" wrote in message
...
Trimmed ....
As simple and cheap as pulse oxymetry has become, perhaps what we
really
need is a simple monitoring and ALARM unit designed for cockpit use. I
happen
to have a Nonin Flitestat but find that it has severe limitations in the
cockpit.


Vaughn

I'd be interested in your opinions on why there are 'severe limitations in
the cockpit '. Could you please elaborate Vaughn

First of all, let me say the the Flitestat is a wonderful instrument for
the purpose I obtained it, which has nothing to do with flying. It was just
last week that I first got a chance to try it in the air.
The main problem is the red LED display which was nearly invisible in
sunlight, even when flying under a cloud shadow. A second problem is the form
of the instrument which nearly procludes piloting while you are checking your O2
level.
I recently saw some disposable tape-on sensors that look like a much better
idea, and there is always the ear clip which may be better yet.

Vaughn

Ian

If the ambient light is too bright the pulse ox will not function since it
measures the pulsatile light at certain wavelengths against baseline or
background light. If the difference between these is not fairly large the
instrument will not be able to determine pulsatility and will thereby not
work.

In the OR we simply place a dark towel or some other "shade" over it. The
same thing can be done in the glider cockpit. I suppose that if the readout
is on the actual instrument itself (finger) that it would be a bit tough
seeing it if covered. Since all pulse oximeters average several cycles it
may be possible to cover it then pull it out from under the shade and still
see a reading before it shuts down.

Also realize that if your hands are cold or you are nervous or perhaps just
downed an extra cup of coffee just before you took off, that there may be
enough vasoconstriction in your extremities that the instrument may have
trouble getting a reading for that reason too.

Casey Lenox
KC
Phoenix

Neptune.. how do you have your news reader set up... I have mine set to only
download the latest 150 postings... so If I make a posting and wait a few
days.. I will not retrieve my original post.. but perhaps some replies in
the thread if the thread is still active.

BT

"Neptune" wrote in message
...
BlankI hate to sound paranoid, but I had put on a posting asking for
information on oxygen systems. It disappeared after several days. I
reposted - same thing - was gone several days later. I then posted what I
thought was a nice bit of information and suggested preflight for the D1 -
same thing - gone after several days.

Frankly I was unaware that anyone could - either technically or
ethically -
erase someone else's post. Maybe this isn't what is happening, if so -
anyone have any idea what is? The messages were in HTML - should this make
any difference?

David Reed M.D., Boulder CO

"Neptune" wrote in message
...
BlankI hate to sound paranoid, but I had put on a posting asking for
information on oxygen systems. It disappeared after several days. I
reposted - same thing - was gone several days later. I then posted what I
thought was a nice bit of information and suggested preflight for the D1 -
same thing - gone after several days.

Frankly I was unaware that anyone could - either technically or
ethically -
erase someone else's post. Maybe this isn't what is happening, if so -
anyone have any idea what is? The messages were in HTML - should this make
any difference?

David Reed M.D., Boulder CO


As you are using Outlook Express as your news reader, have a look at
ToolsOptionsMaintenance. The default is to delete news messages 5 days
after downloading. News servers retain messages from weeks to months. You
may have to delete and recreate you news account settings to recapture these
from the server in your client. Otherwise, http://groups.google.com is
doing a fine job of archiving RFC compliant news groups, unlike the SSA
hosted news groups.

Frank Whiteley
Greeley, CO

BINGO! - Frank Whiteley from Greeley has very kindly identified the problem.
Yes, the rest of you can read the posts but I cannot. He clarified that the
problem is in the way OE default is set up, and I just had never noticed
this before as I had rarely done much with newsgroups until now.

It appears that when you have read a message in a newsgroup, the computer
remembers this for the number of days that you set into
OE/tools/options/maintenance/Delete news messages___days after being read.
Thus if you have set in 5 days, and you access the newsgroup 6 days later,
the message will have disappeared from YOUR computer screen - but not that
of other readers! Once they have read the message, it will then disappear
from THEIR screen the number of days THEY have set in.

Somehow my default had been set at "1" - not that I would have understood
what this meant until Frank clarified it. Bingo! Problem solved.

Fascinating - I had no idea this is the way it works!

Frank (and others) thank you for figuring out the problem. I hope this will
help others, too.

David Reed M.D., Boulder CO

"Neptune" wrote in message
...
BlankI hate to sound paranoid, but I had put on a posting asking for
information on oxygen systems. It disappeared after several days. I
reposted - same thing - was gone several days later. I then posted what I
thought was a nice bit of information and suggested preflight for the D1 -
same thing - gone after several days.

Frankly I was unaware that anyone could - either technically or
ethically -
erase someone else's post. Maybe this isn't what is happening, if so -
anyone have any idea what is? The messages were in HTML - should this make
any difference?

David Reed M.D., Boulder CO