MAST/prehospital interventions - for prehospital providers

[Bill Griggs]

Hi Forrest,

My name is Bill Griggs.  I am a medical specialist and the Director of 
Trauma at an Australian Major Trauma Centre.  I also spent 15 years working 
as a road paramedic and a total of over 30 years working for, and with, 
Ambulance Services.  I assume from your post and from your website that you 
are involved in prehospital care?  I am pleased to see prehospital care 
providers and other non-medical specialists having the "courage" (a careful 
and deliberate choice of word given some of the responses that one may be 
subjected to!) to post questions here.

One of the problems we have as Ambulance Officer/Paramedic/EMTs is that 
during our training we tend to be given "facts" which for the most part we 
have to accept.  The same can be true for medical students. Unfortunately 
medicine is as much art as it is science.  So, as new data are uncovered 
sometimes these "facts" change.

So, as a couple of prehospital examples....
- in the past I have used MAST but based on the current data I would not do 
so again.
- in the past I have given bicarbonate and calcium routinely for cardiac 
arrest but based on the current data I would not do so again.

I note that, for both of these interventions, I can remember individual 
cases where there seemed to be an apparent improvement in a patient's 
condition which was related in time to these interventions.  However the 
data are very clear, for any identifiable group of patients they are bad and 
worsen outcome.  It is really important to avoid the "in my experience" 
fallacy when there are clear data to guide practice.

Did I hurt people with these (and other) interventions?  Probably.  Do I 
worry about that? A little.  How do I deal with that?  I try to accept that 
I was doing what I understood was the best treatment at the time, and that 
what the best treatment might be, is constantly subject to change.

Am I doing something in my practice now which, in 5 or 10 years time (or 
sooner), will be shown to be hurting people?  Undoubtedly.  Do I know which 
bit(s) of my practice that is?  No.  So, I am hurting some people.  What are 
my options?
(1) quit medicine and take up basket weaving or something else. (No offence 
intended to any avid basket weavers out there :-))
(2) keep going and try to adapt my practice in the face of new evidence - 
this means I have to admit to myself that I may be doing things which are 
bad for my patients.  This is an extremely important admission because it 
allows me to discard bad practices when they are identified as such, and not 
cling to them for the sake of "tradition" or because to change would mean I 
have to admit I was wrong.  I have already admitted I am wrong in advance!

With regard to you question about hypoperfused patients, one of the issues 
is that they are many causes of hypoperfusion.  Perhaps not surprisingly, 
what might be good for one cause may be bad for another. To look at your 
example of leg raising, a person who is about to faint but who has normal 
blood volume may benefit from being laid flat and even from having their 
legs raised.  This should improve perfusion to the brain and possibly 
prevent them fainting.  However, while a person who may be about to pass out 
from internal blood loss could be laid flat, raising the legs is not clearly 
of benefit and may actually cause harm.

One theory is when you are bleeding internally, the resulting lowering of 
your blood pressure and vasoconstriction may both act to slow the rate of 
ongoing bleeding - presumably a good thing!  If you raise the legs and 
"autotransfuse"  the patient you may raise the blood pressure and the venous 
filling pressures "tricking" the body's pressure and volume receptors into 
decreasing the amount of vasoconstriction.  In turn these two factors 
(raised BP and decreased vasoconstriction) turn may lead to an increase in 
the rate of bleeding and a hastening of the patient's death.

Clearly there can be many variables and what actually happens will be 
different from patient to patient.

However there are pretty good data showing that transfusing/ infusing 
patients who have ongoing bleeding without controlling the bleeding is a bad 
thing.   I can provide references if you like, but a search of Medline will 
enable you to find articles yourself without having me filter them to 
provide the ones that support my own viewpoint!  You do need to learn how to 
assess articles and their raw data, to enable you to make your own make 
judgements.  This is because, unfortunately, abstracts and conclusions seem 
too often to be at significant variance from what the actual data may say! 
But decide for yourself.

One more point which is important for prehospital providers to understand. 
The best measure of results is patient outcome across a group of patients. 
However this is not what they are like when we drop them in the ER.  It is 
whether they get to go home and what their quality of life is long term. 
Some people will argue that pre-hospital providers can not be responsible 
for what happens in a hospital and therefore the only end point is condition 
on arrival at ER.  This argument is just plain wrong.  Just think what you 
would want if you were the patient?  To have a "good" blood pressure on 
arrival at the ER or to be able to go home alive?  They may not be related 
to each other.  They may, in some cases, even be alternative choices.

Finally, am I a reliable source?  I think so, but maybe not.  I have tried 
to explain my rationale/reasoning and I have told you my background for 
context.   I have told you about data but not shown that data to you, so my 
words must be treated with a degree of healthy scepticism.  Bottom line? - 
if you want to know the answer to something, try looking for some real data 
and critically analyse it yourself - Medline(R) is a good place to start. 
Failing that, ask others, but ask more than one person from more than one 
background, and ask them to please explain the rationale for their views. 
"Coz I say so!" probably doesn't cut it, if you are over 5 years old....

regards

Bill

Dr William M Griggs AM
Director Trauma Service
Royal Adelaide Hospital
South Australia
wgriggs at bigpond.net.au


----- Original Message ----- 
From: "Forrest Robleto" <farcpr at gmail.com>
To: "Trauma &amp, Critical Care mailing list" <trauma-list at trauma.org>
Sent: Tuesday, August 01, 2006 11:52 AM
Subject: Re: Cease fire NOW or prehospital needle thoracotomy


I guess I stand corrected.  I got that information from a source I normally
consider reliable.  It sounded reasonable so I believed it.

Is elevation of the lower extremities useful in hypoperfusion for those of
us without the ability to introduce fluids?


On 7/31/06, docrickfry at aol.com <docrickfry at aol.com> wrote:
>
> I disagree with this urban legend presented as some sort of authoritative
> fact--please cite just ONE study showing any benefit whatever to MAST
> trousers in Vietnam in improving casualty outcomes.  I hope you realize 
> that
> simply raising a blood pressure reading in no way indicates that there was
> any benefit whatever?
> ERF
>
>
> -----Original Message-----
> From: farcpr at gmail.com
> To: trauma-list at trauma.org
> Sent: Mon, 31 Jul 2006 10:41 AM
> Subject: Re: Cease fire NOW or prehospital needle thoracotomy
>
>
> MAST trousers got pretty good results in Viet Nam with young otherwise
> healthy men. When applied accross the general population they didn't fare
> as well.
<snip>