Crush and tourniquets
Hardcastle, Tim, Dr <tch at sun.ac.za>
tch at sun.ac.za
Wed Dec 20 14:25:11 GMT 2006
Jason
Good to see you contribute and appreciate your views. Is there any evidence regarding time of entrapment and extent of entrapment (eg complete limb under wall vs body caught in crashed car, with minimal pressure on limbs) in terms of severity and treatment protocols. You did not mention Carlos Brown's work from LAC. They showed that for CK <15000 the incidence of renal failure was <6% and that bicarb and mannitol had no advantage over saline flush alone. This is my experience here in South Africa too; one of my registrars is writing up our series of close to 500 cases of crush over a two year period at the moment for his M.Med dissertation.
I agree on the exchange resins though, although this effect seems related to longer term rather than acute lowering of the potassium.
The majority of crush injury I see comes from interpersonal violence (locally called kangaroo-court and sjambok assault, you may remember) and from vascular injury reperfusion. Is the effect and outcome different?
The incidence of chronic renal dysfunction in this group is surprisingly small from what my renal unit colleagues, who follow these patients longterm, tell me. If they reverse the renal dysfunction (usually within around three weeks) they seem to have good functional outcomes with a small group having persistant hypertension at five years. the trick is to not let them get dehydrated during the inevitable polyuric phase of recovery.
Regards
Tim
Dr T C Hardcastle
M.B.,Ch.B.(Stell); M.Med(Chir); FCS(SA)
Senior Surgeon / Senior Lecturer: Surgery (Trauma and ICU)
ATLS instructor and DSTC Cape Town Course Director
Intern program Coordinator: Surgery
M.Med (Emergency Medicine) Executive Committee member
Clinical Head (Director): Diana Princess of Wales Trauma Unit
Division of Surgery (General) Room 4064
Department of Surgical Sciences
Tygerberg Hospital / University of Stellenbosch
PO Box 19063
Tygerberg 7505
Western Cape
South Africa
e-mail: tch at sun.ac.za
Cell: +27824681615
Office: +27219389281 or 4911 pager 0302
-----Original Message-----
From: trauma-list-bounces at trauma.org
[mailto:trauma-list-bounces at trauma.org]On Behalf Of Jason Van der Velde
Sent: Tuesday, December 19, 2006 5:06 PM
To: trauma-list at trauma.org
Subject: Crush and tourniquets
You probably knew Karim that I would eventually resist no
more and rise to your initial posting!!! Time to stop
lurking in this fascinating tourniquet debate!!
Apologies for the lengthily reply, but particularly in
light of Dr. Mazur insightful comments, this is not a
simple topic and needs space to be addressed properly. I
believe I write with reasonable authority as apart from my
clinical work, I lecture extensively on the systemic
sequalea of muscle damage. It is the subject of my masters
thesis, and in more detail my envisaged PhD work.
1st an observation: We are a large multidisciplinary
discussion group. Equally trauma is NOT the remit of only
one specialty or professional group. Predictably we all
are approaching what is essentially THE SAME kinematics
and pathophysiological process from different angles,
which is not necessary a bad thing, but may I suggest that
we all need to "think out of the box" that is our
"individual specialties". This is particularly important
for the patient, who's journey is a lifetime, and not the
15min in the ambulance or 2 hours on the operating table.
Crush syndrome kills or seriously disables:
1) on or shortly after extrication (Cardiac
Arrhythmias/thromboembolic)
2) In a few days or weeks (Acute Renal
Failure/Cardiac Arrhythmias/thromboembolic)
3) In a number of years, which as acute clinicians we
frequently forget! (Chronic Renal Failure)
Crush syndrome is a true systemic insult. Apart from the
well know renal complications of muscle damage,
prehospital deaths post extrication secondary to cardiac
arrhythmia, are frequently misdiagnosed as hypovolaemic
arrests and could hold a key to making a significant dent
in post extrication mortality statistics, ie. Peak 1 of
either the Scottish Trauma Audit[i] or Trunkey's[ii]
curve. Hence this is an important subject that requires a
roadside to critical care approach to management.
Electrolyte abnormalities occur frequently in patients
with crush-related acute renal failure.[iii] We have known
about such disturbances for some time now, particularly
the tremendous potential for hyperkalaemia and consequent
fatal cardiac arrhythmias.[iv] What we have not fully
appreciated until quite recently is the staggering
percentage of patients who have died either on scene or
en-route to hospital, as a result of electrolyte
abnormalities during or shortly post extrication.
Important autopsy findings from 111 deaths in the 1999
Athens earthquake have only recently been made public.[v]
Although this study's main purpose was to audit emergency
response as a whole, it begins to give us the first real
evidence to support a long held belief of the adverse
effects of extrication on cardiac function. Researches
from the University of Athens General Hospital evaluated
and combined demographic data, circumstances of death,
rescue time, mechanisms of injury, causes of death,
Abbreviated Injury Scale (AIS 90) and Injury Severity
Score (ISS) values, vital functions and co-morbidity in a
study seeking to identify preventable deaths in Trunkey's
first group. Their findings attributed a staggering 46.6 %
of post extrication earthquake deaths directly to cardiac
complications.
It is hypothesised that this pathophysiological process is
far more common than we think in every day trauma practice
and if this is so, it is clear that we have to drastically
alter our current practices, particularly our prehospital
practices, if we are to make any headway in addressing
mortality/morbidity.
Dr. Mazur has certainly presented this list with a very
logical approach to management. Perhaps I can add to his
comments by providing some additional points as well as
some evidence to back his management strategies up. The
goals are prevention and protection. There is more than
sufficient data to warrant an initial aggressive approach
to preventing fatal cardiac arrhythmias, whilst at the
same time initiating early, renal protective strategies. I
am more than happy to discuss this data further, in depth,
off list.
EARLY identification of at risk patients and assigning
them to a crush protocol is the key. Crush protocols are
not new. We've been studying them and using them since the
1st world war![vi] Now I can safely make the comment that
by the time you have biochemical diagnosis (ie. Serum CK)
of a crush syndrome, it is too late. The decision to
initiate preventative and protective strategies should be
a balanced, educated decision weighing up kinematics,
degree and time of entrapment, environmental influences
and premorbid health against the need for circulating
volume preservation and haemorrhage control. The early
use of myoglobin specific urinary dipstick appears to be a
sensible tool in aiding such an early management
decision.[vii].
I believe that the key is proper training and experience
in identifying at risk patients by the kinematics of
insult alone... How this is done is a whole discussion on
its own. It is also a contentious issue at the heart of
how we manage our prehospital emergency services. But what
is NOT contentious is the overwhelming evidence:
Early aggressive intervention,[viii],[ix],[x] prior to
extrication[xi], has been shown to benefit long term
outcome in entrapped casualties at risk of Crush Syndrome.
WHY prior to extrication??
A NORMOvolaemic, NORMOtensive, NORMOthermic, NORMOetc.
etc. etc. system handles the "ischemic soup" that is
bolused from a released limb far better than one that is
in haemodynamic crisis... If we are going to remove a
crushing force or remove a tourniquet, the body has to be
in shape to handle it! I speak from an anaesthetic
perspective where I manage tourniquet release post
operatively on a weekly basis both electively and as an
emergency. Maintaining systemic normality is standard
perioperative management in orthopaedic, vascular,
plastics etc. etc. surgery. Can you all put hand on heart
and say you release that "ischaemic soup" into a
haemodynamically stable circulation each and every time??
Is this why we get away with it in theatre and not in the
emergency room? I'm not by any means implying that each
and every time we take someone to theatre and put a
tourniquet that we don't have a problem, of course not!
But it is a no-brainer that a haemodynamically stable
patient has a better chance...
WHY prophylactic tourniquets are good??
There should be no ambiguity, that circulation
preservation strategies, i.e. permissive hypotension until
definitive surgical or interventional radiological
management of the haemorrhage, takes precedence over any
crush syndrome protocol. Just thought I'd make that
statement 1st! I do believe in the DDIT approach with
tourniquets as a useful adjunct in the right circumstances
in haemorrhage control... but may I add once again to the
argument.... WITH SYSTEMIC PREOPTIMISATION PRIOR TO RELEASE
!
Do you want a rescuer managing a cardiac arrhythmia during
the extrication? Do want to manage it in an ambulance? Or
do you want SOME control over when it is going to occur?
That is why we teach our rescue personnel to put
tourniquets on, prior to release and call an appropriately
qualified person who is able to start a crush protocol to
go some way to restore systemic normality.
Tourniquets should remain in place until the patient is in
a safer environment, ideally in a hospital resuscitation
bay or theatre, with full cardiovascular monitoring, but
as a sensible compromise, in cases where there is
potentially a long delay to definitive care or a difficult
extrication, the stage release protocol could be used
earlier.
Once in a place of safety, with appropriate monitoring,
appropriate preoptimisation, a staged release of
tourniquets is an entirely logical next approach. This is
currently lacking a clinical effectiveness audit,
something which I aim to tackle as part of a PhD.
The goal is to do a controlled "infusion" as opposed to
"bolus" the inevitable ischemic washout. Tourniquets
should be individually released for a period of thirty
seconds, whilst monitoring the casualty's condition
closely and then reapplied for a period of 3 minutes.
After reapplication, wait for 3 minutes. If the casualty
is stable, release the other tourniquet (if present) for
30 seconds. Repeat this procedure with each tourniquet
being released 3 times until finally being left off.
During this time a large CO2 and therefore acid load will
return to the main circulation. Ventilated patients should
be hyperventilated. Adverse responses can be managed with
further fluid, pressors, calcium and sodium bicarbonate.
To answer Dr. Mazur's question, there is good evidence in
support of the early use of potassium binders such as
sodium polystyrene sulfonate (Sodium or Calcium Resonium)
orally or rectally before patients are extricated and
transferred to hospital.[xii] Should Calcium be used
prophylacticly? Well again, no evidence, but very logical.
I am looking into the possibility of a study in a
particularly earthquake prone country... will let the list
know the results. But I am about to publish one very good
case example where we used such agents periarrest in the
face of massive hyperkalaemia with discharge home 4 days
later!
I leave you with one thought: It can be argued that we
have inadvertently been efficiently managing a huge bulk
of patients at risk of crush syndrome through our
traditionally liberal approach to fluid resuscitation,
throughout the trauma patient journey. With today's more
conservative approach to the use of fluids in trauma,
could we now begin to see a shift away from such problems
as fluid overload and ARDS to those of a crush syndrome?
Dr. Jason van der Velde (EMDM-A, MBChB, BAA)
Disaster Response Coordinator
UN/OCHA Liaison
Anaesthesia Trauma and Critical Care Team
atacc.co.uk
[i] Jonathan Wyatt, Diana Beard, Alasdair Gray, Anthony
Busuttil, and Colin Robertson. The time of death after
trauma. BMJ 1995; 310: 1502
[ii] Trunkey DD. Trauma. Sci Am 1983;249(2):20-7
[iii] Sever MS, Erek E, Vanholder R, et al. The Marmara
earthquake: admission laboratory features of patients with
nephrological problems. Nephrol Dial Transplant
2002;17:1025-1031.
[iv] James PB. Cardiac arrest after crush injury. Br Med J
(Clin Res Ed). 1983 Sep 17;287(6395):839.
[v] Papadopoulos IN, Kanakaris N, Triantafillidis A, et.
al. Autopsy findings from 111 deaths in the 1999 Athens
earthquake as a basis for auditing the emergency response.
Br J Surg. 2004 Dec;91(12):1633-40
[vi] Frankenthal L. Lieber Verschuettungen. Virchows
Archives 1916;22:332-45 (in German).
[vii] Apple, F.S., Y. Hellsten, and P.M. Clarkson. Early
detection of skeletal muscle injury by assay of creatine
kinase MM isoforms in serum after acute exercise. Clin.
Chem. 34(6): 1102-1104, 1988.
[viii] Better OS. The crush syndrome revisited
(1940-1990). Nephron 1990;55:97-103.
[ix] Better OS, Rubinstein I, Reis ND. Muscle crush
compartment syndrome: fulminant local oedema with
threatening systemic effects. Kid Int 2003;63:1155-7.
[x] Malinoski DJ, Slater MS, Mullins RJ. Crush injury and
rhabdomyolysis. Crit Care Clin. 2004 Jan;20(1):171-92
[xi] Gunal AI, Celiker H, Dogukan A, et. al. Early and
vigorous fluid resuscitation prevents acute renal failure
in the crush victims of catastrophic earthquakes. J Am
Soc Nephrol. 2004 Jul;15(7):1862-7
[xii] Sever MS, Vanholder R, Lameire N. Management of
crush-related injuries after disasters. N Engl J Med. 2006
Mar 9;354(10):1052-63.
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