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Permissive Hypotension for Trauma
Resuscitation
compiled by Jon Hoerner
trauma.org (7:10) October 2002
Please mark my word. Within
no less than 10 years, probably even less than 5 years,
any [one] that raises the blood pressure to higher than
3/4 the pre injury level, especially if using crystalloid
solutions will be severely criticized as violating one
of the indicators, whether the injury be penetrating,
blunt, elderly, child, or one's own self or family.
Also mark this down on this
date. The final target for a prehospital or EC measured
BP will be that greater than 80 SYSTOLIC will be the level
that the QA moral police will cite that those of you who
believe in two large bore IVs, Rapid infusors, interosseous
and sternal infursors, the 3 to 1 rule, and cyclic hyper
resuscitation as causing unnecessary complications, deaths,
and costs.
Ken Mattox.
Trauma.Org Trauma-List,
30th August 2002
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The following is a full archive
of one of several debates regarding permissive hypotension that
has taken place on the Trauma-list over the past few years.
Read Ken Mattox's editorial
on Permissive Hypotension.
There is an extensive biblography
of references regarding permissive hypotension
that has been compiled by Barry Armstrong to accompany this discussion.
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From: Abhishek Mitra
Date: Tue 20/08/2002 18:44
I am a medical intern working in Kolkata, India. I wonder
if anyone in the list has any thoughts on "hypotensive resuscitation"
as opposed to rapid infusion of fluids in the management of
hypovolaemic shock. According to Bailey and Love's Short Practice
of Surgery, "An increasingly accepted view holds that moderate
hypotension - systolic blood pressure of 85 - 90 mm Hg - is
sufficient to maintain vital organ perfusion and avoids a
hypertensive overshoot with the risk of precipitating further
haemorrhage". I have never seen it in practice here and would
like to know if any of you has any experience with it.
Regards,
Abhishek
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From: Avi Roy Shapira
Date: Wed 21/08/2002 06:51
Yes. we have seen it in practice. But it is not for hypovolemic
shock, only for hemorrhagic shock. If the hypovolemia is due
to cholera, other GI losses or third spacing in major burns,
for example, giving fluids is still the right way to go.
In a bleeding patient, a BP > 80 "pops the clot". Keeping
the patient hypotensive slows the bleeding, prevents hemodilution,
and, strangely enough, does not increase the incidence of
ATN. There is a large and growing body of literature that
supports this concept.
Avi
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From: Chris Cotton
Date: Wed 21/08/2002 13:02
Dr Ken Mattox just posted this answer yesterday to a question
of mine and a few others on CCM-L about this very topic and
what end points we should be aiming for. Here is a copy of
his reply (I hope he doesn't mind me posting this):
ALL of the large animal studies have shown that the level
of SYSTOLIC BP in such a case should be kept at 80/- until
there is control of bleeding. Any higher blood pressure results
in the "POP THE CLOT" syndrome and increases the rebleeding,
the cyclic hyper resuscitation, blood usage, post op complications
and DEATH. Remember 80 !! We have now found that we like to
keep the BP lowish even after operative control of hemorrhage
as it keeps secondary bleeding from hematoma sites down and
decreases dilutional coagulopathy.
k
and then in response to further questioning, he goes on to
say about fluid loading:
YES, as long as someone somewhere, (ambulance, emergency
physician, anesthesiologist, intensivist,others) has not given
excessive (in view, none in the ambulance or EC as long as
there is the presence of ANY peripheral pulse (?BP 80/-),
None in the EC, unless very small volumes are required for
antibiotics,etc. ). Certainly the total volume in ambulance,
EC, preop holding, etc. should be less than 500 ml.
k
...Food for thought in my opinion. Hope this helps.
Regards,
Chris Cotton
IC Paramedic
South Australia.
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From: Stephanie Stafford
Date: Wed 21/08/2002 15:54
isn't this for penetrating trauma? does the same apply for
blunt trauma? we used this to delineate for hydration and
bp in trauma pts in seattle. penetrating got less fluids,k
blunt stil had pretty aggressive hydration.
stephanie stafford, DO
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From: Matt Dunn
Date: Wed 21/08/2002 12:56
In controlled haemorrhage, preoperative fluid therapy is
not needed (patient will hold vital organ perfusion at a level
that will not cause organ damage in the time it takes to get
to theatre)
In uncontrolled haemorrhage, preoperative fluid therapy
is ineffective (dilutes the blood and causes increased bleeding).
The biggest problem is when haemorrhage is controlled by veins
being collapsed (or by a poor clot). In that circumstance,
preoperative fluid risks converting controlled to uncontrolled
haemorrhage. This is opinion. Animal models vary. Computer
models vary.
The only RCT concerned penetrating thoracic trauma and showed
preoperative fluid worsened outcome. Some anaesthetists say
that if you don't give preoperative fluids the blood pressure
crashes at induction. However, there is no evidence that giving
preoperative fluids or not makes any difference to this. There
is extensive correspondence on this issue in the list's archives.
Matt Dunn
Warwick
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From: Rowley Cottingham
Date: Thu 22/08/2002 07:02
Strewth, the same old chestnuts keep surfacing,
don't they?
1. Drs Mattox and Bickler have shown that
in their rapid and well-organised urban transit environment
people who get to theatre with penetrating wounds of the thorax
and neck do better if no fluid is administered before surgery
starts.
2. Dr Sue Stern of Ann Arbor has shown that
pigs anaesthetised with thiopentone and halothane do better
after aortic laceration if no fluid is administered before
they are allowed to recover.
3. I have been shown no evidence (and Dr
Mattox has never responded to this challenge) that there is
any benefit to patients who have sustained blunt trauma from
withholding fluids.
It may well be that Dr Mattox's theory is
right, and that there is a benefit to allowing the blood pressure
to slide in blunt trauma too, but it is a theory, and has
not been backed by experimental evidence in an appropriate
animal or human model to the best of my knowledge. I also
have reservations about the applicability of this treatment
to older patients and to patients with penetrating trauma
and long transit times.
However, it is wonderful that people are
thinking about fresh approaches to trauma management, and
ideas such as high osmolality, low volume infusions and induced
hypothermia are being actively researched. I do wish to remind
people of the difference between theory and evidence.
Best wishes,
Rowley Cottingham
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From: Yoram Klein
Date: Mon 26/08/2002 15:01
I think we should be very careful with this
concept. In my mind, the correct term should be permissive
hypotension and not hypotensive resuscitation (like permissive
hypercapnia and not hypercapnic ventilation). That means that
in situation in which the bleeding might be uncontrolled,
normal blood pressure shouldn't be our target. Since there
is evidence to suggest increased bleeding secondary to fluid
resuscitation and elevated blood pressure, maintaining perfusion
with lower blood pressure is a reasonable approach. If the
patient demonstrates signs of hypoperfusion (depressed level
of consciousness, profound hypotension etc.), fluid and blood
resuscitation should be stated immediately and aggressively
even before surgical control of the bleeding is achieved.
Yoram Klein MD
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From: Michael Damm
Date: Tue 27/08/2002 07:04
Mr. Rowley Cottingham had posted a very important message/question:
Where is the evidence for withholding "pre-hopspital fluid/volume
resuscitation" in blunt trauma? Europe sees predominately
blunt trauma, so do we up here in Seattle & King County (MEDIC
ONE) and we keep aggressively volume resuscitate (successfully)
these individuals.
Michael Damm, MICP
King County MEDIC ONE
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From: Pret Bjorn
Date: Tue 27/08/2002 13:13
If it's evidence you're after, then you're not going back
far enough: where is the evidence which suggested prehospital
fluid resuscitation to begin with? What little I've seen stems
from medical models, not trauma. Surely, if we were able to
clean our collective experiential slates and start afresh,
we would wonder at the value of pouring water into a leaking
wine skin. It may indeed be up to science to debunk our long-cherished
assumptions and traditions; but that doesn't make our assumptions
or traditions any more correct in the meantime. Airway, breathing,
bleeding control, and hospitalization: I can scrape together
a beefy bibliography in no time. But lactated Ringer's is
much more difficult to justify.
Pret Bjorn, RN, etc.
Trauma Coordinator
Eastern Maine Medical Center Trauma Program
Bangor, ME USA
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From: John Holmes
Date: Tue 27/08/2002 01:27
I agree - the term "Resuscitation" implies
a return to normal life - some dictionary definitions even
go as far as to say a return to vigour. The hypotensive trauma
patient is not returned to anything approaching normalcy until
after requisite surgical control of haemorrhage and organ/tissue
repair has taken place. The best we can do in the preoperative
phase is provide analgesia and comfort, support and control
airway, breathing and judiciously the circulation ie: by maintaining
a BP adequate for life but not likely to "pop clots". In fact
this is really just another aspect of the presurgical requirement
to prevent any secondary injury.
The term "permissive hypotension" describes
this situation accurately as long as we remember that it remains
the lesser of two evils. We permit the patient to remain hypotensive
only because it is the lesser of two evils - the greater evil
being the exacerbation of haemorrhage from an as yet uncontrolled
site if BP rises too far. However, resuscitation it ain't
and "Hypotensive resuscitation" is a contradiction in terms.
John Dr J Holmes
Director Emergency Medicine
Mater Hospitals, Brisbane, Australia
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From: Matt Dunn
Date: Tue 27/08/2002 12:42
> If the patient demonstrates signs
> of hypoperfusion (depressed level of consciousness,
> profound hypotension etc.), fluid and blood
> resuscitation should be stated immediately and
> aggressively even before surgical control of the
> bleeding is achieved.
I don't think this particularly follows.
As has been said previously, the evidence for permissive hypotension
is limited. However, if you accept the rationale that giving
fluids converts controlled to uncontrolled haemorrhage, then
this is the case even if there are signs of impaired perfusion.
A patient with bleeding that stops when their SBP drops to
70 (and they reduce cerebral perfusion to the point of confusion)
is best kept at that pressure (if you believe in permissive
hypotension)
> Mr. Rowley Cottingham had posted a very
important
> message/question: Where
> is the evidence for withholding "pre-hopspital fluid/volume
> resuscitation" in blunt trauma? Europe sees predominately
> blunt trauma.
Computer models at best, and I don't believe
them. Equally there is no evidence that giving fluids improves
outcome (for researchers this is an important point- there
is no gold standard to compare new fluid regimes to). Dr Mattox's
work in penetrating thoracic trauma showed that research into
giving or withholding fluids in trauma is useful and ethical.
Blunt trauma is more homogenous. Nonetheless the research
would be useful. To assume that giving fluid is the best thing
until evidence is found to the contrary is a mistake. Giving
moderate amounts of fluid is acceptable practice, withholding
fluid is acceptable practice. (There is some evidence against
cyclical hyperressucitaion). In blunt trauma we do not have
the evidence for or against moderate preoperative fluids.
On that basis, however, delaying operation to give fluids
is unacceptable, criticism of colleagues for withholding fluids
or giving moderate amounts is unwarranted and putting resources
into ways of getting fluids to the patient earlier (level
1 warmers, motorcycle paramedics for trauma) is unjustified.
Matt Dunn
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From: Eric Frykberg
Date: Tue 27/08/2002 23:08
>Airway, breathing, bleeding control, and
hospitalization: I can scrape together a beefy bibliography
in no time. But lactated Ringer's is much more difficult to
justify.
Pret-- Apparently you are quite unfamiliar
with a wealth of elegant studies from the '60's and '70's
strongly supporting volume infusion as an effective treatment
for shock, and R/L in particular--by such figures as Shires,
Canizaro, Blaisdell, Robert Wilson, Trunkey, Flint, Lucas,
Ledgerwood, etc etc. Also many studies from earlier in this
century supporting this. Certainly these results can be debated,
as can permissive hypotension --there are flaws on both sides
of the debate here--on each side the methodology and conclusions
can be nickeled and dimed. But this is a far cry from claiming
NO evidence! Beware of the classic trap of assuming that what
you are not aware of simply can't exist--I can give you a
start if you like on the refs.....
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From: Avi Roy Shapira
Date: Wed 28/08/2002 02:59
Eric,
These were indeed elegant studies for their
time. Have you taken the trouble to review them lately? If
you do, you will find that the endpoints they used were not
outcome measures but physiologic parameters: urine output,
PAWP, extracellular fluid levels etc. None of them used survival.
Moreover, many of these studies were done in the context of
comparing one fluid regimen to another, for example crystaloids
vs colloids. The overall need for fluids was not challenged.
(Just like antibiotic papers. They always
compare old, cheap compound A to new,improved, and of course
expensive, compound B. No difference in survival is ever observed
and there is never a challenge to the use of antibiotics in
the first place.)
These classic papers were wonderful in their
time. Today, we have learned that physiologic endpoints are
useless when comparing treatments. Only real outcome measures
are and should be accepted as guides for treatment. These
outcome measures are primarily survival, but I will also buy
reduced hospial stay(= economic benefit), or reduced disability.
This is what evidence based medicine is all about.
Avi
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From: Avi Roy Shapira
Date: Wed 28/08/2002 03:17
> If the patient demonstrates signs
> of hypoperfusion (depressed level of consciousness,
> profound hypotension etc.), fluid and blood
> resuscitation should be stated immediately and
> aggressively even before surgical control of the
> bleeding is achieved.
I believe this is a non sequitor. Either
you believe in the popping the clot theory or you don't. If
you do, signs of hypoperfusion do not matter.
Otherwise, what you are saying that if the
patient is in shock (=hypoperfusion signs) he should be aggressively
ressucitated with fluids, and that takes away all meaning
of hypotensive ressucitation.
Of course if the patient has a systolic blood
pressure of 90, but is cheerful and making urine, fluids don't
matter. Such a patient will survive regardless of what you
do.
The only intersting case (for the purpose
of this debate) is the patient who is obtunded, oliguric,
with > 30% blood loss. This patient will have signs of hypoperfusion
per definition.
Avi
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From: Yoram Klein
Date: Wed 28/08/2002 23:05
Avi,
I believe that fluid resuscitation might
increased bleeding. I'm also convinced that prolonged hypoperfusion
leeds to ischemia-reperfusion, MOF, and death. So, there are
situations in which the patient will have overt decompensate
shock, and I will start fluid resuscitation immediately -even
before control the bleeding is achieved. By the way, if you
have a trauma patient in the OR, that suffers from massive
bleeding from a high grade liver injury, do you ask the anesthesiologist
not to give the patient fluids until you control the bleeding
(which might take a long time)?
Yoram
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From: Pret Bjorn
Date: Wed 28/08/2002 14:47
Rick,
Thanks, I'll take you up on your offer. I'm
not above admitting when I'm wrong--although I am insistent
on first detailing the degree of transgression. It's an ego-preservation
thing. I'll admit from the start that my exposure to trauma
in the 60's and 70's was largely restricted to the kinematic
case examples of Bugs Bunny and Johnny Quest (thoroughly flawed,
but nonetheless timeless). On the other hand, I've found that
scientific studies from that era--in many respects the dawn
of modern trauma care--are surprisingly difficult to retrieve.
And when one considers that those were also the days of PASG's
and tourniquets, one is forced to regard any clinical recommendations
as more historical than seminal. I stand by my quote, and
await your references with interest.
Nice job on the disaster response piece in
the JoT, incidentally.
Pret
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From: Avi Roy Shapira
Date: Thu 29/08/2002 04:01
Dear Yoram,
Yes. I do. It does not take a long time
to control the bleeding from a high grade liver injury. Packing
will always stop the bleeding quickly, provided you know what
you are doing.
Remember that the water pressure in your
kitchen faucet is about 4.3 atmospheres (at least in Israel)
that is about 3000 mmHg. Yet I am sure that as a child you
managed to stop the flow with your thumb for a while.
Compare that to arterial pressure: it is
at least 30 times less, while you are much stronger than you
were as a five years old.
Blood flows in a low pressure system, and
therefore will always stop with pressure. If you are unsuccessful,
you are not doing it right.
So open the abdomen with a cold knife, ignoring
subQ bleeders, and pack quickly. You wil control the bleeding
within 2-3 minutes of first incision.
Then ask the anesthesiologist to give fluids,
but not over do it. And if packing stopped the bleeding, be
happy. Don't pack and peek.
Avi
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From: Ken Mattox
Date: Fri 30/08/2002 04:45
Please mark my word. Within no less than
10 years, probably even less than 5 years, any paramedic,
nurse, flight personnel, EC personnel, anesthesiologist that
raises the blood pressure to higher than 3/4 the pre injury
level, especially if using crystalloid solutions will be severely
criticized as violating one of the indicators, whether the
injury be penetrating, blunt, elderly, child, or one's own
self or family.
Also mark this down on this date. The final
target for a prehospital or EC measured BP will be that greater
than 80 SYSTOLIC will be the level that the QA moral police
will cite that those of you who believe in two large bore
IVs, Rapid infusors, interosseous and sternal infursors, the
3 to 1 rule, and cyclic hyper resuscitation as causing unnecessary
complications, deaths, and costs.
The bills for this excessive cost, time in
the ICU, cost of treating the complications will be transfered
BACK to the person (EMT, Paramedic, Nurse, Doctor, or protocol
person) who contributed to the complication or death.
k
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From: Ken Mattox
Date: Fri 30/08/2002 04:45
YES, It all will soon be published in a special
suppl;iment to the Journal of Trauma. It is a Bethesda Consensus
Conference and the sjpecial suppliment is being edited and
put together by Dr. Howard Champion and the Department of
Naval Research. Rest assrued that representatives from ALL
sides of this issue were present, as well as presons from
ALL armed services and many countries of the world. The consensus
was a great surprise and basically the final coffin nail to
aggressive cyclic hyper-resuscitation in the ambulance, EC,
and preoperative holding areas whereever they exists. Ironically,
I could only be there for the first two days, and the final
consensus was reached after most of the vocal fluid restriction
persons had left. In spite of that, many of you on this list
server will be utterly surprised at the recommendations and
the overall consensus,.
k
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From: Nanto Cielens
Date: Fri 30/08/2002 06:57
How many pre-hospital emergency services
are still using large volume fluid resus in hypotensive trauma
patients? My service accepts a systolic BP of 100mmHg. Patients
with head injuries, spinal cord transection and chest injury
do not get IV Hartmanns and in penetrating trunk injuries
we accept BPs of 60-80mmHg (ie a carotid pulse). Our guidelines
say in bold "There must be no additional scene time spent
establishing IV fluid therapy". Those few that do now get
fluid receive 20mL/kg Hartmanns to a BP of 100mmHg.
Nanto Cielens
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From: John Black
Date: Fri 30/08/2002 13:50
Ken,
This clarity is great news. On the practical
side, do you feel that the recently published UK consensus
guidelines for use fluid replacement in prehospital care(i.e.
250 ml bolus(es) of crystalloid titrated to the presence/absence
of a radial pulse) is reasonable in the field?
For what it is worth I am not surprised;
you have covered many issues below - could you confirm that
reduced GCS in its own right is of enormous prognostic significance.
Do you have any idea where we can expect to see these consensus
guidelines in press?
John Black
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From: Mark Forrest
Date: Fri 30/08/2002 18:59
Thank you Ken, as a fellow 'believer' and
someone who has been around this thread several times before
on the list, I totally agree with your comments.
Despite the work in the 60s and 70s there
is no adequate evidence base for the current cyclic resus
and excessive use of fluids. So many individuals call for
the evidence for permissive hypotension .....well were is
the evidence for the current 'drownings' that we see every
day in trauma care. Many list members have previously told
me that they do not use excessive volumes of fluid in resuscitation
any more, yet they are often only looking at a small part
of the trauma care...the roadside, the resus room, the operating
theatre and then the ITU. Put them all together and each bolus
of fluid given in each area results in litres and litres of
over-transfusion. In my own hospitals, which are better than
most, I see patients on the ITU, 12 hours post injury, who
lost only 1-2 litres of blood, yet they have received 10litres
of fluid or more. If you wish to look for evidence against
excessive resuscitation and you don't accept 'popping the
clot', haemo and coagulo-dilution and hypothermia problems,
then consider the ITU sometime later.....acute lung injury,
ARDS, impaired oxygen delivery, huge 'third space losses'.
Research does not directly link trauma and later critical
care problems as cause and effect are often so far apart and
multi-factorial, yet that does not mean that they are unrelated......a
little common sense?!
Common sense?....Trauma care in Norway this
year, this was discussed on numerous occasions by numerous
respected academics. Evidence base is good and should be followed
wherever we can. However, we should not ignore common sense.
Someone will always argue that there is no evidence that jumping
out of a plane without a parachute will save you and they
may even argue that it may increase mortality.....but applying
common sense, which would you go for?
What about flow? Those against 'Permissive
hypotension ' will argue that it results in reduced flow to
the organs that matter. Well, numerous anaesthetic techniques
involve hypotension , often profound (retinal tumour surgery),
without any apparent ill effects, even in an elderly population.
A well oxygenated patient, lying flat does not need a systolic
>100mmHg to perfuse the 'bits that matter'. Similarly, patients
without head injury will remain conscious and orientated until
blood pressures fall well below 100mmHg and this supports
the Bethesda recommendation of 'no fluids until conscious
level deteriorates' then small volume boluses until it improves.
An excellent and highly practical 'assessment and treatment'
method for in-the-field care.
I would also like list members to explain
to me why bleeding from penetrating and blunt trauma should
be so different. I understand the kinematics and the nature
of the injuries but I still believe that bleeding is bleeding
and a clot is a clot. For the 'drowners' out there, show me
the improved survival with your technique and the current
SOC and don't dismiss a new technique because no one has yet
published. I am with Ken and the 'less fluid is best movement'!!
Ken and I differ in our thoughts on hypertonics...... do you
just use even less fluid or none at all??? As for the head
injured....that's more of a problem!
Regards
Mark F
UK
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From: Abhishek Mitra
Date: Fri 30/08/2002 19:28
Dear all, When I put in the question last
week, I really didn't think it would spark off such a lively
discussion. Thank you all for sharing your views on the subject
and I must say I know much more now than I did when I first
read about it. However, being an absolute greenhorn and working
in a hospital where few people have heard about it, let alone
having used it in practice, I have the following question:
How do you ensure that the systolic BP stays in the 80 mm
range, given that BP depends on a large number of factors
and not just blood volume.
Also, how does one approach the patient in
the situations where: i) initial systolic BP is below 80 mm
Hg. ii) initial systolic BP is above 80 but rapidly falling.
I need to know whether you start infusions
at all in the above situations, and if so, the choice of fluid,
the rate calculation and when to stop infusion. I have also
heard several references in the discussion to "pre-injury
BP". In case a patient is found to be in shock and unconscious,
how does one know the pre-injury BP? In that case does one
assume the normal range to be the pre-injury BP?
Thanks and regards,
Abhishek
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From: Ken Mattox
Date: Fri 30/08/2002 23:29
I would observe that the new UK guidelines
of 250 ml bolus in the presence of a peripheral pulse is overly
aggressive and in the future brave new world, they will be
a focus of criticism
k
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From: Matt Dunn
Date: Fri 30/08/2002 12:45
Now if only I were a betting man. Dr Mattox,
I respect your view and its intellectual basis. However I
feel you are being optimistic about the time between evidence
and its use in practice. Witness steroids for prevention of
RDS in the new-born- about 30 years between class 1 evidence
of a large effect and common practice. In permissive hypotension
the evidence is at best limited, the effect if present is
not huge (based on the assumption that a larger effect would
have been picked up earlier). Most importantly, you are aiming
for an intervention that does not benefit any pharmaceutical
company (it's cheap- or in this case free) and goes against
certain vested interests (the view among some paramedics and
a larger proportion of their administrators/ teachers that
they should be doing prehospital interventions for instance-
no prehospital fluids moves to a load and go policy in trauma,
so why not just use drivers, possibly with a few weeks training
in simple airway manoeuvres and spinal 'immobilisation' for
trauma. Similar views found among some emergency physicians
and anaesthesiologists for similar reasons). I'd guess 30
years to be nearer the mark. I will be pleased to be corrected.
Matt Dunn
Warwick
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From: Judy
Date: Fri 30/08/2002 18:20
Interesting, when the new traumatic brain
injury data shows even ONE episode of a BP less than 90 systolic
greatly increases mortality. Who was the author of that.......I
couldn't tell.
Judy
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From: Rowley Cottingham
Date: Sat 31/08/2002 06:11
Ken, Show the research as outlined in my
previous posting and then I'll listen. Bluster don't impress
me.
I cannot let this go unchallenged either.
I deeply resent being classed as a 'drowner' because I refuse
to jump on a bandwagon with only one wheel. I have never advocated
overfilling patients with crystalloid or colloid. Indeed,
some of the worst problems I see are caused by my anaesthetic/ITU
colleagues (I left anaesthesia some years ago) who only want
to see a CVP of +10 to +15cm H20! Now that strikes me as drowning.
They call it a good driver for the left side of the heart
- I call it a recipe for disaster. My granny used to say that
the right dose of any medicine was enough - what we disagree
on is what is enough. You admit yourself that a patient with
a (presumably blunt) brain injury (I really don't give a stuff
about the head, but I do give a stuff about accuracy) cannot
be managed with hypotension - and maybe that is simply because
it is easier to see the consequences of hypoperfusion. Maybe
everything else suffers a bit too, but we don't have sensitive
enough tools to be sure. As an example; doubling of the serum
creatinine requires destruction of 90% of nephrons. Why should
the brain, an organ with the most efficient flow protection
system of all in the carotid syphons be uniquely at risk from
hypoperfusion?
I am now teaching that blunt and penetrating
trauma are two separate diseases that happen to share a common
cause - the application of excess mechanical force to the
body. I cannot accept that the correct management for an expanding
retroperitoneal haematoma is to let the patient exsanguinate
into it. Bleeding always stops for one reason or another,
and sometimes in blunt trauma (nay, probably most times) that
is tissue tamponade. The notion that clot is like a bandage
round a garden hosepipe that pops if you turn the tap up too
high is a ridiculous oversimplification of the complex haemodynamic,
biochemical and hydrostatic issues that constitute haemostasis.
I say (yet again) - Ken may be right. Mark
may be right. But let us not rush headlong into this. And
for goodness sake stop confusing fluid replacement with gross
overinfusion!
Best wishes,
Rowley Cottingham
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From: Mark Forrest
Date: Sat 31/08/2002 23:49
So you don't 'overfill' patients Rowley,
well then presumably you are not a 'drowner', but then you
are in the minority and appear to agree in some way with the
'less fluid is best' concept?! Sadly, the 'drowners' are still
out there in every hospital, chasing that tachycardia with
litre after litre of fluid instead of rapidly moving to definitive
care. We are all still waiting for the evidence to support
this current management strategy.
As for your ITU colleagues running CVPs of
>10cmH20...look again and consider the likely high PEEP values
that these patients are on using open lung strategies.....are
your quoted CVPs true indications of over-filling (right or
left)?? This may explain the views of your intensivists as
most in our area run ITU patients increasingly 'dry', using
pressors if necessary, rather then excessive volumes of fluid.
There is no audit evidence to suggest an increase in ATN in
our units since this 'dry' regime, but even if there was,
this is far easier condition to manage and has a better prognosis
than severe ARDS.
Regarding the bleeding patient.... Who said
anything about letting patients exsanguinate with retroperitoneal
haematomas?? If they are bleeding to this degree they require
surgical control.....still don't see how aggressive fluid
therapy 'chasing a tachycardia' is going to help.
As for the 'pop the clot' over simplification
view. On the contrary, I would suggest that the soft tissue
tamponade concept is even more of a simplification as 'popping
the clot' takes into account the concepts of pressure effects,
reduced viscosity and dilutional coagulopathy! Fluid therapy
vs over-infusion: I too have questioned Ken's view of 'give
no fluid' on this very list. I do use fluids in trauma care,
but titrated to a radial pulse or blood pressure of >80systolic.
Head injuries (usually also involves the 'brain', but only
by assumption in the pre-hospital and resus domain!!) obviously
present more of a problem as many of the normal 'blood-flow
protective' mechanisms are lost in such injuries and the damage
related to hypotension has been well demonstrated. What is
our target then ?>100systolic?
Whatever fluid resuscitation regime that
we apply, it is essential to consider the volume replacement
that we are using. What are our targets? Does this patient
really need another litre of crystalloid or can we turn that
drip off? Can we leave that second venflon capped off?
What I am advocating is not my own wild
flight of fancy, but rather the use of good clinical skills
to assess the blood loss and to then use the minimum amount
of replacement fluid to restore an 'adequate' circulation
to get the patient to definitive care, without making them
any worse. What are your current resuscitation targets Rowley
in penetrating, blunt and brain injury?
Finally, whatever happened to 'do no harm'
because whatever you say Rowley the 'drowners' are still out
there 'doing harm litre after litre of fluid runs into our
patients whilst they are being managed after trauma!
Regards
Mark F UK
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From: Massimo Cristaldi
Date: Sun 01/09/2002 07:15
Having followed with interest the discussion
on permissive resuscitation I would say that in no way fluid
replacement have to delay the definitive surgical care in
unstable patients or stable patients with indication to surgical
exploration. The amount of fluid given (crystalloid and blood
as soon as you get it in ER, following an estimation of losses
and clinical response) to the patient in the hospital setting
are in my personal opinion intended to restore an adequate
circulation during the time of resuscitation before rushing
the pt to OR. Anyway if it's true that the surgical control
of the hemorrhage is the crucial keypoint on the other hand,
without a proper initial fluid replacement therapy, in many
of the severe trauma pts admitted to ER, we would not have
time to reach a surgical control of the hemorrage. This night
while operating an abdominal blunt trauma with multiple visceral
injuries that required to me 15/20 minutes to cont rol the
bleeding I gl mpsed the blood bag doing his job and I felt
pretty happy to have it on my side.
I think it's wonderful to discuss about
topics like this without dressing the crusader armour. Thank
you.
Massimo Cristaldi MD, FACS
initiate Assistant Professor of Surgery
University of Milan
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From: Haim Paran
Date: Sun 01/09/2002 17:38
Do any one from the list actually know about
any ongoing clinical trial on this subject? I feel that we
all have been going around and around on this issue. The great
majority of surgeons dealing with trauma on an everyday basis
feel that permissive hypotension is the right way to handle
these patients. The problem is we are all lacking the class
1 evidence. The only trial that I am aware of, which actually
tested the hypothesis on a prospective clinical trial, was
performed by Dr. Mattox, but it is only one study. Maybe we
could try to plan an multi-center ( international ?...) trial
using this wonderful list. Until then we can continue to convince
the already convinced, but most patients will continue to
get drowned.
Haim Paran MD
Dept. of |Surgery
Meir Hospital, Israel
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From: Barry Armstrong
Date: Sun 01/09/2002 18:31
Haim: Agreed that further studies are necessary
to confirm experimental results from animal studies. Available
animal studies strongly indicate that fluid infusion should
not precede hemorrhage control. The study by Mattox et al
looked at only penetrating trauma. Dutton et al (see below),
in a small study, showed that permissive hypotension did not
worsen mortality in a mixed trauma population.
Barry Armstrong
Dryden, Ontario, Canada
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From: Dean Lutrin
Date: Mon 02/09/2002 07:48
So it seems obvious what we need
1. A study looking at trauma systems with
a longer prehospital time than the major US cities (Houston,
Seattle etc) to see if the permissive hypotension doctrine
applies when prehospital times are extended.
2. A study looking at permissive hypotension in blunt trauma.
3. A study looking at permissive hypotension (blunt or penetrating
trauma) in the presence of a head injury
As far as I gather, permissive hypotension
causing low (or low-normal) cerebral perfusion pressure in
the ABSENCE of head injury is not catastrophic Well, easier
said than done, but it seems like this is what should happen
so that we can make sound decisions with good evidence.
Dean Lutrin
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From: J. David Roccaforte
Date: Mon 02/09/2002 15:23
Mark,
I've looked through the abstracts of the
list you posted. Thank you. My guess is that your and my actual
practice is not so dissimilar.
You wrote: "The excessive volumes of resus
fluid..."
I think the key is to define "excessive."
I would agree that bolusing just to get the HR from 105 to
below 100 is pointless in an otherwise stable patient. But
if someone is in shock, and if tissue perfusion parameters
(however you want to measure them) improve in response to
a fluid challenge, I don't think it matters that it's their
1st or 30th liter. then they need that volume, it's not excessive.
The following article puts an interesting
spin on the whole "enough v. excessive" resuscitation endpoint:
J Trauma 2001 May;50(5):826-34
Irreversible shock is not irreversible: a new model of massive
hemorrhage and resuscitation.
Healey MA, Samphire J, Hoyt DB, Liu F, Davis R, Loomis WH.
Department of Surgery, University of Saskatchewan, Saskatoon,
Saskatchewan, Canada.
BACKGROUND: Existing shock models do not
address the patient with massive hemorrhage (> 1 blood volume).
Such patients often die from irreversible shock. This model
simulates the clinical scenario of massive hemorrhage and
resuscitation (MHR) to determine if irreversible shock can
be reversed. METHODS: Lewis rats were bled at a rate of 1
estimated blood volume (EBV) per hour for 2 hours with simultaneous
infusion of resuscitation mixture (RM) consisting of red blood
cells and crystalloid. Blood pressure was maintained at a
mean arterial pressure (MAP) of 50 mm Hg during the 2 hours
of hemorrhage. Hemorrhage was stopped and resuscitation continued
for 1 hour until 6, 8, or 10 x EBV of RM was infused. Control
animals were subjected to a traditional fixed pressure hemorrhage
to MAP of 50 mm Hg for 2 hours followed by resuscitation to
MAP > 90 mm Hg for 1 hour with crystalloid alone. Two-week
survival was compared using a chi2 test. RESULTS: Control
animals (n = 13) were hemorrhaged 48% +/- 5% of EBV and had
a mortality rate of 23%. MHR animals had severity and duration
of hypotension identical to that of controls but were hemorrhaged
214% +/- 8% of EBV. Despite receiving 390 mL/kg of RM and
a final hematocrit of 37%, 14 of 15 animals resuscitated with
6 x EBV died from "irreversible" shock (mortality, 93%; p
< 0.001 vs. controls). When very large volumes of resuscitation
were used, survival rates improved significantly. The 10 x
EBV group received 120% of lost red blood cells and 530 mL/kg
of crystalloid and had 64% survival at 2 weeks (p < 0.01 vs.
6 x EBV group). CONCLUSION: This MHR model is much more lethal
than a traditional severe hemorrhage model and reproduces
the clinical picture of irreversible shock. This irreversible
shock can be reversed with very large volumes of resuscitation.
regards,
david
J. David Roccaforte M.D.
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From: Rowley Cottingham
Date: Wed 04/09/2002 06:12
Well, quite. One of the criticisms I have
levelled at Drs Bickler and Mattox' study is that it is in
a well-organised, well-resourced system where someone can
realistically expect to be in an operating room having their
penetrating injury dealt with rapidly. As has been pointed
out in the past few days, more data is needed in a variety
of trauma systems before we agree what we are doing. It is
almost a reductio ad absurdem situation that you fill the
hole before any blood can come out of it!
These arguments all put me in mind of the
researcher who was looking at steroids in smoke inhalation
in the 1970s. After a great deal of work with rats, he was
asked what the optimum time for treatment with steroids was.
He thought for a few moments, and then said, "About ten minutes
before exposure."
Best wishes,
Rowley Cottingham
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From: Tim Hardcastle
Date: Tue 03/09/2002 18:43
A question for all you FIRST world surgeons
out there: How does one apply this policy of of hypotensive
resusucitation in the situation which we are forced into in
my country on a regular basis, namely that we experience OR
waiting times in excess of 6 hours for major trauma just because
of the workload!!
This past weekend we had 30 trauma laparotomies
from Friday till Monday evening, seven of which were for gunshots.
We also had 2 GSW femoral artery as well! We only have one
non-orthopaedic emergency OR which is shared by all the other
surgical disciplines, except O&G. With that kind of workload
we really struggle to not over-resus patients. (We have four
Trauma Surgery residents)
Any advise would be appreciated Kind regards
Tim
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From: Matt Dunn
Date: Wed 04/09/2002 13:33
You are still thinking in terms of cyclic
hyperresuscitation I think.
Possible scenarios:
1. Patient well perfused, normotensive. Controlled
haemorrhage. Does not need pre- op fluids.
2. Patient hypotensive but perfusing brain
and kidneys. Controlled haemorrhage. Does not need pre- op
fluids (if you believe in the concept of permissive hypotension
)
3. Patient uncontrolled haemorrhage. Seems
very unlikely to survive a 6 hour wait to stop bleeding (6
hours of significant bleeding; fluids likely to produce coagulopathy).
4. Patient with controlled haemorrhage but
hypotensive and with signs of failure of end organ perfusion
(anuria, depressed conscious level etc).
This is where the main argument for pre-op
fluids to bring up the BP/ perfusion comes in. The trouble
is that you risk knocking off the existing clot and chasing
the blood pressure rather than controlling the bleeding. The
question is whether 6 hours of this is better or worse than
6 hours of anuria. Personally I'd opt for the anuria- the
cascades leading to multi organ failure have already cascaded
so you are likely to lose the kidneys whatever you do. Permissive
hypotension cuts the risk of bleeding out. Accept the inevitable,
avoid the avoidable. (OK, I might consider a revision to accept
moderate confusion and urine output of over 15 ml/ kg/ min-
or some other higher or lower figure-, but trickle in fluids
if it dropped below that).
None of this has been well studied, so we
are relying on poor quality evidence mainly. However, accepting
that, the concept of permissive hypotension is just as valid
in South Africa (or the Falklands) as in Houston. (The question
of how valid that is remains).
Matt Dunn
Warwick
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trauma.org (7:10) October
2002
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