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Home > Articles > Permissive Hypotension: Discussion Archive

"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.

The following is a full archive, compiled by Jon Hoerner, 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.

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

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

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.

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

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

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

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

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

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

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

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

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.....

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

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

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

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

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

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

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

m: Nanto Cielens
e: 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

m: John Black
e: 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

m: Mark Forrest
e: 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

m: Abhishek Mitra
e: 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

m: Ken Mattox
e: 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

m: Matt Dunn
e: 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

m: Judy
e: 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

m: Rowley Cottingham
e: 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

m: Mark Forrest
e: 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

m: Massimo Cristaldi
e: 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

m: Haim Paran
e: 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

m: Barry Armstrong
e: 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

m: Dean Lutrin
e: 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

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.

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

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

From: Matt Dunn
e: 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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