List Archives

Wed Oct 25 18:32:13 BST 2006

Ron,

I'd love to have those references also. I did a 1 month course with the
MIEMS HBO guys back in the day. Of course I was all excited about it then
and was definitely taken aback by the vehement opposition from the surgical
community back home. Even for stuff like radiation necrosis which at the
time I'd thought had pretty positive science. But please no flames, I
haven't read the lit in over 20 yrs.

Rob 

-----Original Message-----
From: trauma-list-bounces at trauma.org [mailto:trauma-list-bounces at trauma.org]
On Behalf Of Ronald Gross
Sent: Wednesday, October 25, 2006 1:06 PM
To: Trauma &amp; Critical Care mailing list
Cc: George Perdrizet
Subject: RE: FW: Carboxyhemoglobin Levels

Pret,
How unlike you to be so opinionated - sorta like the guy who doesn't know
how to answer when asked, by his wife's divorce lawyer, "Exactly when did
you stop beating your wife?"  No facts to base his assertion upon, but made
it anyway.

I would refer you to an extensive body of literature (most but definitely
not all of it well researched and written) that will show even those who
have already made up their minds to the contrary, that there actually are
disease processes out there that are in need of this particular treatment.  

Before you impale yourself on the sword of the  "anti-hyperbaric religious
right stance", I humbly suggest that you come down south a couple hundred
miles from your perch in Maine to a city called Hartford (still, last I
checked, on planet Earth) and avail yourself to the knowledge of a pretty
savvy clinician, educator, scientist and researcher (Dr. George Perdrizet)
and look at the results of the hyperbaric medicine program that he has
developed and brought along. 
You just might think twice before launching into the sort of thing that Rob
Smith was referring to the other day - and that I mentioned above - and that
would be religious condemnation of that which we are not really familiar
with.

Just my humble opinion.......
Ron

>>> "Bjorn, Pret" <pbjorn at emh.org> 10/25/2006 9:50 AM >>>
You don't read many pages on HBO before you bump into the assertion that
it's basically a treatment in search of a disease.  But beyond that debate,
let me observe that its benefits -- anecdotal, academic, hypothetical or
otherwise -- must be measured in the context of what a pain in the ass it
is.  

Finding, accessing, and delivering care in a chamber matching the needs of a
critically ill or injured patient usually generates more risk and
frustration than benefit.  A chamber with real medical functionality is, for
most of the planet, out of reach.  Little wonder that there's no reliable
literature when the proper equipment is far more likely to be found on a sub
base than in a licensed hospital, much less a trauma center.  

JMO

Pret Bjorn
Bangor, ME USA

-----Original Message-----
From: trauma-list-bounces at trauma.org
[mailto:trauma-list-bounces at trauma.org] On Behalf Of Ian Seppelt
Sent: Tuesday, October 24, 2006 10:54 PM
To: Medic541 at hotmail.com; trauma-list at trauma.org
Subject: Re: FW: Carboxyhemoglobin Levels

COHb is merely a marker of CO exposure and the absolute level does not help
a lot without knowing the history (and mechanism) of intoxication and
duration of oxygen therapy before the blood was taken.

It is unfortuantely a medical student myth that CO causes "hypoxic hypoxia"
by irreversibly binding to Hb. While the irreversible binding bit  is true,
it is irrelevant. A patient with COHb 50% is likely to die (even though
there is still 50% oxyHb) while a patient who has lost half a blood volume
on the road (replaced with Ringers) could well be fine, depending on what
the injuries are.

A dog experiment from the 1970s involved severe CO exposure (to COHb 60
- 70%) and then exchange transfusions. The intoxicated dogs died anyway,
even with perfectly good non CO blood from donors, whereas when the COHb 70%
blood was infused into other volunteer dogs they were fine, and just behaved
as if they were a bit anaemic (increased HR and CO).

In fact the problem with CO is what the molecule does at the tissue and
enzymatic level, for example the irreversible lipid peroxidation which
explains all the neurological toxicity from CO.

In terms of therapy there is a large can of worms, polarised by true
believers and non believers. True believers in HBO point to significant
improvements in things like the long term neurological sequelae of CO
intoxication, but the quality of evidence is at the level of case series.
There are serious flaws in most of the controlled trials. The strongest is
Weaver LK, Hopkins RO, Chan KJ, Churchill S, Elliott CG, Clemmer TP, Orme
JF, Thomas FO, Morris AH. Hyperbaric oxygen for acute carbon monoxide
poisoning. New England Journal of Medicine 2002;347(14):1057-67. 

It is also likely that outcomes vary depending on aetiology. In Australia
most CO intoxication is either due to attempts at suicide, or due to
enclosed fires (ie house fires, where a lot of other nasties are inhaled as
well). In colder climes much more of the exposures are industrial or
accidental, and it is likely that outcomes are different in these different
groups.

The most recent Cochrane review is attached for your interest.

Cheers, Ian

Ian Seppelt FANZCA FJFICM
Senior Staff Specialist
Dept of Intensive Care Medicine
The Nepean Hospital, PO Box 63 Penrith NSW 2751 Clinical Lecturer,
University of Sydney

>>> Medic541 at hotmail.com 24/10/2006 7:42am >>>
To all on this group.  Some advice is needed regarding carboxyhemoglobin
levels on certain patients.  What levels are permissible to treat only with
1.0 Fio2?  What levels are treated with a hyperbaric therapy?  Let's start
from neonates all the way up to the elderly.  If anyone has some advice or a
website that might point me in the right direction.  That would be helpful
as well.  I'm trying to find hard numbers, but I cant seem to Google it for
the life of me.  
  Thanks'
  Anthony M. Caruso
  NREMT-P

--
trauma-list : TRAUMA.ORG
To change your settings or unsubscribe visit:
http://www.trauma.org/traumalist.html 

######################################################################
Attention: 
This message is intended for the addresses named and may contain
confidential information. If you are not the intended recipient, please
delete it and notify the sender. Views expressed in this message are those
of the individual sender, and are not necessarily the views of Sydney West
Area Health Service.

This e-mail has been scanned for viruses
######################################################################
--
trauma-list : TRAUMA.ORG
To change your settings or unsubscribe visit:
http://www.trauma.org/traumalist.html

--
trauma-list : TRAUMA.ORG
To change your settings or unsubscribe visit:
http://www.trauma.org/traumalist.html

List Archives

For your convenience, find the Trauma List Archive Below

FW: Carboxyhemoglobin Levels