> Permissive hypotensive resuscitation has been increasingly accepted
> since the work of Ken Mattox in Houston made it respectable several
> years ago.
>
> However in blunt trauma the theory is not so attractive intuitively -
> never mind the evidence for a moment. The patient does not often arrive
> with a label "blunt abdominal trauma", they just come in with multiple
> blunt injuries. The ATLS approach suggests a rapid fluid bolus, and the
> bolus must be rapid principally so one can judge the patient's
> response, i.e. responder, transient responder and non-responder. As
> many of these patients can be managed conservatively the ATLS approach
> works well, and this is where the Mattox approach does not work so well.
I know and greatly respect Ken Mattox (and have crossed swords with him) but, as I said above one makes a huge error
in deductive reasoning when one applies data that works for one problem to another. I was trying to make the point very
clearly (although Robbie thought I was insulting him) by finding a validated treatment for a condition which it would be
nonsensical to apply to blunt trauma.
The work on permissive hypotension actually comes out of the management that (if I remember correctly) Jenny Jones
and her co-workers described for ruptured abdominal aortic aneurysm in the 1970s at St Mary's Hospital in London. They
showed elegantly that patients did better awaiting surgery if the blood pressure was allowed to drop to a systolic of
around 100. This simply meant that there was less of a force causing exsanguination through the tear in the weakened
atherosclerotic abdominal wall. So far so good, but the operation got a poor reputation for the patient developing and
then dying of acute renal failure a few days later. Everyone said that the result was "because of renal artery involvement"
- but was it? Could the ATN simply have resulted from hypoperfusion?
More recently, Sue Stern and her group in UCLA have looked at the porcine model of acute haemorrhage. They
anaesthetised pigs with what she described as a cardiostable anaesthetic (of which more anon) and lacerated the aorta in
a controlled fashion to allow bleeding of a percentage of blood volume. Some pigs were given fluid resuscitation, and
some were not. The pigs allowed to bleed without fluid resuscitation 'did' better. However, I should point out that when I
asked Sue what her cardiostable anaesthetic was, it turned out to be induction with thiopentone and maintenance with
halothane. The anesthetists reading this will not recognise that as the first choice for a cardiostable anaesthetic, and
even less an anaesthetic one would feel comfortable administering to a shocked patient. However, bear in mind that the
pigs were well when anaesthetised.
As you say, Ken Mattox, an extremely experienced and aggressive war surgeon working in urban Houston, then showed
that patients with penetrating thoracic wounds had a lower mortality if they were taken straight to theatre and
anaesthetised for surgery without prior resuscitation.
Does anyone recognise our patients in this description? Yes, if someone comes in tonight with a stab wound - it will
require one procedure to block the hole and stop the bleeding, and the sooner the better. That much I am happy Ken has
validated. What of the motorcyclist who is going to need his fractured left femur nailed (that's bleeding) his pelvis
tamponaded (as that is bleeding but isn't a nice open book that will respond to ex-fix) and a head CT to see what is going
on in there? His management needs thought and prioritisation. Will dropping his blood pressure help him? Well, his
femur might bleed less. However, his pelvic fracture will soak up his clotting mechanisms just as much if not more, as the
tamponading effect will develop more slowly, and the evidence is that hypotension will definitely worsen cerebral
perfusion as autoregulation will break down in areas of brain injury. My thesis is that if we apply what is known to work
for penetrating trauma to blunt trauma we are treating the wrong condition. We must start to look at penetrating and
blunt trauma as two separate entities and not as "trauma".
So far, the discussions have centred on young fit people or pigs. A great deal of our work in Western societies is now
with older or elderly people. What is the effect on their cardiovascular systems of sustained pressures of 90 systolic? We
have a bit of the answer from Jenny Jones; they seem to tolerate it sometimes - but the mortality rate of ruptured aortic
aneurysm is hardly one to take as your benchmark.
> Both protagonists to this debate have their merits; while Rowley's
> approach might have the edge from an intuitive point of view, I think
> it would be wrong to dismiss Robbie's approach just because there is no
> evidence. In other words, why should we default to the traditional ATLS
> approach rather than to the more controversial permissive hypotensive
> approach in the absence of hard evidence?
I hope that I have given some reasons here that are slightly more than intuition. Should someone show that maintaining a
patient with blunt trauma of any age with a blood pressure of 90 (not stabbed youngsters or anaesthetised, lacerated
pigs, real blunt trauma patients) for an indeterminate period of time with or without an operation is beneficial then of
course I shall adopt it. Something tells me that this will not be shown, and what will be shown is that meticulous attention
to reasonable perfusion and oxygenation of uninjured areas, coupled with gentle handling to minimise additional trauma
of frangible clot and appropriate decisions on surgery will achieve much better results than trying to adapt a magic bullet,
'one treatment cures all' approach. These patients are often extremely complex to manage safely and satisfactorily; by
comparison I find patients with penetrating trauma usually need one operation to cure them.
Best wishes,
Rowley Cottingham
Consultant in Emergency Medicine.
Eastbourne DGH.
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