This is a multi-part message in MIME format.

------=_NextPart_000_0053_01C183B3.5FCADEC0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 7bit

Jeff, Here's something from my files.
Ken
----- Original Message -----
From: <swanncruz@oc*.ne*.au*>
To: James Dibbs <James.Dibbs@op*.co*.au*>; 'techdiver list'
<techdiver@aquanaut.com>
Sent: Wednesday, December 12, 2001 9:46 PM
Subject: Re: Oxygen Clock and profiles, O2 narcotic value.


> Dear James, List,
> You are asking George to plan a dive he is ideologically apposed to.
> 0-40m Nitrox
> 40+ Trimix
> Put air in your tyres.
> An over simplification, if you compare this with the GUE recommended
mixes.
> We have been doing some dives in a 100m hole down at Pine Creek.
> I was down the recently doing some shallower stuff (40m), and I thought
the
> following was interesting.
> Back gas EAN 32.
> Stage trimix 20 O2/ 15 He.
> Stage EAN 50.
> I dropped down to 40m on back gas and changed to the stage of 20/15.
> On the nitrox I did not feel narcosis, but my head seemed to clear on the
> trimix.
> The amount of nitrogen was virtually the same in both mixes.
> I do not think the difference in sensation was psychosomatic.
> Hence, is there a recognised narcotic value of oxygen?
> I have not seen it documented, but on atomic weight, it should be higher
> than nitrogen.
> Jeff the Darwinian, OZ.
>
> ----- Original Message -----
> From: "James Dibbs" <James.Dibbs@op*.co*.au*>
> To: "'techdiver list'" <techdiver@aquanaut.com>
> Sent: Thursday, December 13, 2001 7:43 AM
> Subject: Oxygen Clock and profiles
>
>
> >
> > "Give me an exact dive that you want to do or are doing and I will give
> you
> > and exact run for it as I would do it."
> >
> > George.
> >
> > Could tell me how you would do the following dives: 25 min and 30 min @
> 50m
> > and 55m.
> >
> > These are relatively short dives compared to some of the stuff you do
but
> I
> > would like to be able to use the knowledge you have acquired about
> > decompression.
> >
> > The profiles dives above cover almost all of the diving we do in the
> Sydney
> > area.
> >
> > Deco gas is nitrox 50%, bottom gas is air (until I can find an
instructor
> > who teaches a trimix course I'm happy with).
> >
> > Billy Williams tells me that Andrew Georgitsis (spelling?) was planning
to
> > come out to Australia to do some trimix courses sometime in the near
> future.
> > Are you aware if GUE teaches the deco methods used by the WKPP.
> >
> > Thanks in advance
> >
> > James Dibbs
> > Sydney, Australia
> >
> > -----Original Message-----
> > From: trey@ne*.co* [mailto:trey@ne*.co*]
> > Sent: Tuesday, 11 December 2001 23:19
> > To: Osman Tosun
> > Cc: techdiver@aquanaut.com
> > Subject: RE: Oxygen Clock and profiles
> >
> >
> >
> > My deco is in the text of the stories. We have been recording these now
> with
> > the Suunto computers set to gauge mode. We download those and merely
write
> > down the run times for each gas change. Hunsucker will be publishing all
> of
> > that. I did not want any decos put into the dive reports on WKPP or the
> GUE
> > site unless they were identical to what I prescribe to avoid confusion.
It
> > is interesting that the guys who do not do it my way always have a worse
> > result when tested.
> >
> > The dive profiles you are asking about come under what I call the
"minimum
> > deco requirement", meaning that they will not appear as proportionally
> short
> > as the long profiles which hit saturation. Give me an exact dive that
you
> > want to do or are doing and I will give you and exact run for it as I
> would
> > do it.
> >
> > -----Original Message-----
> > From: Osman Tosun [mailto:osman_tosun@ya*.co*]
> > Sent: Monday, December 10, 2001 11:09 AM
> > To: Trey
> > Cc: techdiver@aquanaut.com
> > Subject: Re: Oxygen Clock and profiles
> >
> >
> > Hi George,
> >
> > Let me introduce myself first as a recent observer on
> > the list and a recreational/ weekend tech diver who
> > dives in the warm waters of the Philippines, run times
> > rarely exceeding 2hrs.
> >
> > I was very interested in following the thread on
> > oxygen management during deco and the descriptions of
> > your pioneering profiles as you mentioned.  I had a
> > quick surf through the WKPP site but could not really
> > find profiles as such.  I saw your standard mixes and
> > summary dive reports giving depth and bottom time.
> > Please could you point me in the right direction to
> > where I could find your deco profiles/ running times.
> > I am particularly interested in your shorter dives!
> > Say, less than 330 ft and bottom times in the order of
> > 30 mins.  For example looking at the dive reports for
> > 2000: Feb 5 Sally Ward Spring 245 ft for 25 mins or
> > June 23 Wakulla 280ft for 25 mins.
> >
> > Thanks in advance,
> >
> > Osman Tosun.
> > --- Wendell Grogan <wgrogan@dc*.ne*> wrote:
> > > Trey,
> > > A minor point, but important.
> > > On breaks from O2, the closer you get to real
> > > normoxia (i.e.. 21%) the
> > > better.  In fact, if you get down to the 17% range,
> > > there is some
> > > evidence that is even better.  Air, at 20 feet is
> > > 0.34 ppO2.  Most
> > > bottom gas mixes are going to be best.
> > > Wendell
> > >
> > > Trey wrote:
> > > >
> > > >  The short version of the answer is that we came
> > > up with this ( 12 on , 6
> > > > off )by trying everything and arriving at that. We
> > > knew from any of our
> > > > diving that long exposures to higher ppo2s left us
> > > feeling like we had a
> > > > chest cold. We started out with the usual crap
> > > that is taught out there ( 20
> > > > on then break ) and found that to be useless. We
> > > found loss of vital
> > > > capacity with these regimens.  Now we have no such
> > > negative results.
> > > >
> > > >  The oxygen takes less than 12 minutes to reach as
> > > high an effective
> > > > saturation level as is useful. Beyond that the
> > > body reacts by constricting
> > > > blood vessels everywhere which limits off gassing,
> > > by trying to protect the
> > > > lining of the lungs and hence thickens the
> > > transfer area by adding cells and
> > > > excreting mucous which impedes gas transfer, and
> > > by causing swelling of the
> > > > lung tissue which further reduces gas exchange
> > > capability, not to mention
> > > > scarring and long term damage that in my opinion
> > > will come back to haunt the
> > > > agencies who teach the baloney.
> > > >
> > > >   Returning to a more normoxic ppo2 will reverse
> > > these effects. However, if
> > > > you do not return soon enough, the effects take a
> > > lot longer to reverse. The
> > > > big and important thing here is not to depend on
> > > reversing this action, but
> > > > to preempt it and keep it from fully developing
> > > and thus make what does
> > > > occur easier to reverse and at the same time
> > > actually improve your off
> > > > gassing by opening the capillaries back up and
> > > allowing gas to escape from
> > > > the tissues into the blood. This "toggling" back
> > > and forth has proven to be
> > > > the absolute best method of gas use in
> > > decompression. DIR deco.
> > > >
> > > >   If you fail to do this at any point in the deco
> > > using high ppo2s you will
> > > > merely be holding gas in tissues which may expand
> > > before it can be removed
> > > > as you move up - another massive flaw in all of
> > > the existing deco programs.
> > > >
> > > >   As you get higher in the water column, off
> > > gassing is more safely and
> > > > effectively achieved by the moving the gradient
> > > and letting gas bubble into
> > > > the bloodstream and be caught and removed by the
> > > lungs, but lower down this
> > > > will not work - one more huge flaw in deco
> > > programs.
> > > >
> > > >   You really should look on the WKPP site and read
> > > some of my profiles and
> > > > decompressions on the longer dives to see all the
> > > massive deviations from
> > > > what is thought to be correct by the agencies.
> > > >
> > > >   In fact, I will tell you right now that this is
> > > just like deep air - the
> > > > same idiots who fought for their precious deep air
> > > are the ones who teach
> > > > the most incorrect deco and theories of deco. The
> > > same people - give them a
> > > > wide berth in all areas of diving since you can
> > > NOT teach pigs to sing.
> > > >
> > > >   If want real information, come to the proven
> > > sources.
> > > >
> > > > -----Original Message-----
> > > > From: Charles Roth [mailto:divr555@ho*.co*]
> > > > Sent: Sunday, December 09, 2001 2:53 AM
> > > > To: trey@ne*.co*; techdiver@aquanaut.com
> > > > Subject: RE: Oxygen Clock
> > > >
> > > > Trey,
> > > > In fear of sounding stupid, yes, I would really
> > > like to know how you all
> > > > came up with this. Or at least point me in the
> > > right direction to find the
> > > > resources about this.  Thanks.
> > > >
> > > > Chuck R
> > > >
> > > > >From: trey@ne*.co* (Trey)
> > > > >To: "Isaac Callicrate" <icallicrate@ho*.co*>,
> > > <mjblackmd@ya*.co*>,
> > > > ><techdiver@aquanaut.com>
> > > > >Subject: RE: Oxygen Clock
> > > > >Date: Sat, 8 Dec 2001 07:35:10 -0500
> > > > >
> > > > >
> > > > >Isaac, we have found that 12 minutes on, 6
> > > minutes off is the ideal. We
> > > > >only
> > > > >do oxygen at 30 feet in a habitat where we have
> > > caves that accommodate
> > > > >this.
> > > > >Otherwise we do oxygen at 20 feet or slightly
> > > less in the water with the
> > > > >same schedule. If anyone wants to go back over
> > > why we do this and how we
> > > > >determine bottom gas , deco gas and exposure ( or
> > > how we arrived at what we
> > > > >do), I can repeat it .
> > > > >
> > > > > >-----Original Message-----
> > > > > >From: Isaac Callicrate
> > > [mailto:icallicrate@ho*.co*]
> > > > > >Sent: Saturday, December 08, 2001 2:51 AM
> > > > > >To: mjblackmd@ya*.co*; techdiver@aquanaut.com
> > > > > >Subject: Re: Oxygen Clock
> > > > > >
> > > > > >
> > > > > >Im not sure why everyone is harping on who this
> > > guy is or what he
> > > > > >has posted
> > > > > >in the past instead of answering his questions.
> > > > > >Am I missing something in the charter that says
> > > you have to rate an
> > > > >answer
> > > > > >or that previous posts disqualify you from
> > > getting one?
> > > > > >Ill give it a shot even though there are
> > > probably more informed qualified
> > > > > >people on this list that should be.
> > > > > >I see WKPP as crossing the grey area between
> > > recreational and
> > > > > >working diving
> > > > > >(watch out for OSHA, ADC, and USCG). They are
> > > performing dives where more
> > > > > >compartments are saturated than most other
> > > recreational profiles.
> > > > > >They have
> > > > > >been diving similar profiles over and over so
> > > have built up an amount of
> > > > > >historical data combined with some doppler
> > > research that they have used
> > > > >to
> > > > > >make assumptions about their profiles.
> > > > > >I dont think anyone can say right or wrong yet.
> > > If their people
> > > > > >arent having
> > > > > >DCS manifestations or O2 toxicity issues than I
> > > would definately
> > > > > >say that by
> > > > > >being the guinea pig and letting the rest reap
> > > the rewards of the
> > > > > >data they
> > > > > >are rising above.
> > > > > >Please do the math on a Navy standard TT 6A
> > > with 50/50 @ 165' and 100% @
> > > > > >60'. Do it on a Navy single exposure of 100% at
> > > 25' for 240 minutes.  Why
> > > > > >havent you e-mailed them? Please CC me when you
> > > do. I think it is
> > > > > >publicaffairs@ne*.na*.na*.mi*
> > > > > >WKPP isnt the only one that challenges
> > > theoretical formulas and
> > > > > >assumptions
> > > > > >with historical data. Commercial, military,
> > > hyperbaric facilities all
> > > > >have
> > > > > >modified the standard thinking on the CNS
> > > clock.
> > > > > >My personal feelings, I wouldnt recommend
> > > pushing the clock on a working
> > > > > >dive when not required. For recreational dives,
> > > there is no need
> > > > > >to push it
> > > > > >when you are having fun. If you use a habitat
> > > or a chamber or
> > > > > >maybe at rest
> > > > > >during deco with surface support, the risk is
> > > minimized.
> > > > > >I dont think that taking breaks off O2 is going
> > > to significantly
> > >
> > === message truncated ===
> >
> >
> > __________________________________________________
> > Do You Yahoo!?
> > Send your FREE holiday greetings online!
> > http://greetings.yahoo.com
> >
> > --
> > Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'.
> > Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
> >
>
> --
> Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'.
> Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
>

------=_NextPart_000_0053_01C183B3.5FCADEC0
Content-Type: message/rfc822;
	name="Oxygen narcosis.eml"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
	filename="Oxygen narcosis.eml"

Return-Path: <quest-return-6841-kennyp=snowhill.com@gu*.co*>
Received: from SMTPSCAN.snowhill.com (smtpscan.snowhill.com [216.47.193.225])
	by frost.snowhill.com (8.11.1/8.11.1) with SMTP id f0NIr2m12953
	for <kennyp@sn*.co*>; Tue, 23 Jan 2001 12:53:02 -0600 (CST)
Received: FROM sacred.net BY SMTPSCAN.snowhill.com ; Tue Jan 23 00:53:47 2001
-0600
Received: (qmail 10664 invoked by uid 1059); 23 Jan 2001 18:51:56 -0000
Mailing-List: contact quest-help@gu*.co*; run by ezmlm
Precedence: bulk
X-No-Archive: yes
list-help: <mailto:quest-help@gu*.co*>
list-unsubscribe: <mailto:quest-unsubscribe@gu*.co*>
list-post: <mailto:quest@gu*.co*>
Delivered-To: mailing list quest@gu*.co*
Received: (qmail 10653 invoked from network); 23 Jan 2001 18:51:55 -0000
Message-ID: <412F4D3C5614D211853600A0C99E563F070F50A5@co*.me*.ui*.ed*>
From: "Brian, Eddie" <eddie-brian@ui*.ed*>
To: "'quest@gu*.co*'" <quest@gu*.co*>
Subject: Oxygen narcosis
Date: Tue, 23 Jan 2001 12:52:11 -0600
MIME-Version: 1.0
X-Mailer: Internet Mail Service (5.5.2448.0)
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 8bit
X-MIME-Autoconverted: from quoted-printable to 8bit by frost.snowhill.com id
f0NIr2m12953
X-DPOP: DPOP Version 2.5g
X-UIDL: 980278143.018
Status: U

Narcotic Properties of Oxygen

Based on study of animals and humans, oxygen is a narcotic gas. Based on
lipid solubility, oxygen should be twice as narcotic as nitrogen, as oxygen
is twice as soluble (see table). However, as several individuals have
pointed out, the increase in tissue partial pressure of oxygen is limited as
the oxygen is metabolized. This means that for any given increase in the
inspired partial pressure of oxygen, the change in tissue partial pressure
is less. 

Study of the narcotic properties of oxygen is limited by oxygen seizures; so
study of oxygen narcosis in humans have been limited to lower partial
pressures where "narcosis" is more subtle and difficult to test for. In
animals, treatment to suppress seizures allows exposure to very high PO2's,
and exposure to 11 ATA O2 produces anesthesia in mice 1. In humans, testing
for psychomotor performance indicates that 1.65 ATA O2 is about equal to 6.3
ATA N2 in narcotic effect 2. 

Measurements of change in brain PO2 under hyperbaric conditions are limited
in number, and also limited to animal studies. In animals, exposure to 2.34
ATA O2 produced a brainPO2 of 291 mmHg (1 ATA = 760 mmHg) 3. Assuming a
normal partial pressure of CO2 of 40 mmHg, alveolar PO2 would be 1738 mmHg,
so the ratio between alveolar and brain PO2 is 219/1738 = 0.17, which means
that the rise in brain PO2 is only about 1/6 the rise in inspired PO2. If we
now apply the correction for lipid solubility, (twice as soluble/narcotic),
oxygen should be about 1/3 (0.17 x 2 = 0.34) as narcotic. This takes into
account both the lipid solubility and the change in brain PO2. In the human
study cited above, oxygen was 1.65/6.3 = 0.26 as potent as nitrogen. The
calculated (0.34) and measured (0.26) values are in reasonable agreement.

By the way, if we use the definition of "non-inert" to mean that the drug
has to participate in direct chemical reactions, then almost all drugs,
including all anesthetics would be "inert". Nitrogen and other inhaled
anesthetics do not participate in direct chemical reactions, but clearly
they are not physiologically inert. 


 Gas	Bunsen Solubility Coefficient in Olive Oil, 22�C, ata-1	
Helium				0.015	
Hydrogen			0.042	
Nitrogen			0.052	
Oxygen			0.11	
Argon				0.15	
Krypton			0.44	
Carbon Dioxide		1.34	
Nitrous Oxide			1.56	
Xenon				1.9	

Eddie Brian


References:

1. Paton WDM: Experiments on the convulsant and anaesthetic effects of
oxygen. British Journal of Pharmacology and Chemotherapeutics
1967;29:350-366.
2. Hesser CM, Fagraeus L, Adolfson J: Roles of nitrogen, oxygen, and carbon
dioxide in compressed-air narcosis. Undersea Biomed Res 1978;5:391-400.
3. Bennett PB: Cortical CO2 and O2 at high pressures of argon, nitrogen,
helium, and oxygen. J Appl Physiol 1965;20:1249-1252.


---------------------------------------------------------------------
To unsubscribe, e-mail: quest-unsubscribe@gu*.co*
For additional commands, e-mail: quest-help@gu*.co*
------=_NextPart_000_0053_01C183B3.5FCADEC0--

--
Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'.
Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.

Navigate by Author: [Previous] [Next] [Author Search Index]
Navigate by Subject: [Previous] [Next] [Subject Search Index]

[Send Reply] [Send Message with New Topic]

[Search Selection] [Mailing List Home] [Home]