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Mon Aug 6 14:57:48 BST 2007

Carol,

Thanks, great point, yes, the fear would be that by using pressors instead of (or perhaps together with) crystalloids you could have consequences of the low CO - acidosis & eventually perhaps DIC also. We're really talking about short-term administration right now though, temporizing prior to obtaining blood products and control of bleeding. 

My question still remains that if you increase CO with crystalloids, you don't increase the O2 delivery (perhaps minimally by Starling effect & increase of contractility), so any potential for hypoxia and acidosis in the constricted-off organs may not be very different from when you give pressors. It's a fake improvement that keeps the BP & CO perhaps but does it really do anything else good for the patient ?

The body when in shock does that itself, (you could say it is more natural to use pressors than to give liters of crystalloid,) it constricts the less vital organs off with endogenous pressors, angiotensin, AVP & catecholamines.

I need the physiologist among us to help me: is it the need for perfusion pressure or pulse pressure that you achieve with crystalloids to get effective blood flow through the organs as to the great resistance of the huge web of capillaries within organs that are squeezed by the interstitial pressure ? But that pressure cannot be more than 20 mm Hg right (unless high ICP) ?

I know that O2 delivery depends on the product of Hb and CO  - but remember: you decrease the Hb with the administration of crystalloids (=hemodilution). 

So here's the hypothesis: The vasoconstriction (that the body normally does itself anyway even without our discourse) that preserves perfusion and flow in the vital organs with blood with a high hematocrit - is a better way to preserve the vital organs. If you support that vasoconstriction with pressors you give the vital organs what they normally get and you're not giving them crystalloid-hemodiluted blood together with the non-vital organs.

Obviously the vital organs are vital and the other organs are not - the splanchnic etc. After a while you'll get in trouble undeperfusing them but it takes a while until they start dying out and producing cytokines that kill the rest of the body too.

As far as problems with crystalloids: one difference may be that I work in the OR and see patients ending up getting over 10 L of crystalloid and become swollen like a "Michelin Man".
That swelling is probably worst in an injured brain, but bad everywhere. There are many deleterious effects of crystalloids, immunologicallly, effects on coagulation (hyper), dilutional coagulopathy eventually etc.

Ivan

> Date: Mon, 6 Aug 2007 13:08:02 +0000> From: czuehlke at frontiernet.net> To: trauma-list at trauma.org> Subject: Re: trauma-list Digest, Vol 50, Issue 12> > Hi Everyone:> I was thinking about what the effects of having vasopressin for any > length of time would do over the crystalloids. It seems that all the > blood shunting from th drug and the trauma would most likely make the > patient a candidate for DIC. Am I wrong? This could get really ugly > before it gets better. I have used crystalloids in our ED for years > and have had no problems with this method, except of course > hemodilution. Help me here, I am trying to see the logic behind the > vasopressin to begin with.> Carol> > Quoting trauma-list-request at trauma.org:> > > Send trauma-list mailing list submissions to> > trauma-list at trauma.org> >> > To subscribe or unsubscribe via the World Wide Web, visit> > http://list.mistral.net/mailman/listinfo/trauma-list> > or, via email, send a message with subject or body 'help' to> > trauma-list-request at trauma.org> >> > You can reach the person managing the list at> > trauma-list-owner at trauma.org> >> > When replying, please edit your Subject line so it is more specific> > than "Re: Contents of trauma-list digest..."> >> >> > Today's Topics:> >> > 1. Re: TEST - Integrated Collaborative TRAUMA/Disaster Network> > (Juan Anzieta Neumann)> > 2. pressors in trauma, wasn't the world once flat? (Mike Smertka)> > 3. Why are crystalloids better > pressors ? (IVAN HRONEK)> > 4. Re: Why are crystalloids better > pressors ?= NEITHER> > (KMATTOX at aol.com)> > 5. Re: Why are crystalloids better > pressors ?= NEITHER> > (Alex Garbino)> > 6. Bullet Removal (Andrew J Bowman)> >> >> > ----------------------------------------------------------------------> >> > Message: 1> > Date: Sun, 5 Aug 2007 19:32:57 -0400> > From: "Juan Anzieta Neumann" <janzieta at telsur.cl>> > Subject: Re: TEST - Integrated Collaborative TRAUMA/Disaster Network> > To: "Trauma &amp; Critical Care mailing list" <trauma-list at trauma.org>> > Message-ID: <006501c7d7b8$f45cdf70$0401010a at Personal2>> > Content-Type: text/plain; format=flowed; charset="iso-8859-1";> > reply-type=original> >> >> > ----- Original Message -----> > From: "AMAT ROCA, MIGUEL" <19505mar at comb.es>> > To: "Trauma &amp; Critical Care mailing list" <trauma-list at trauma.org>> > Sent: Saturday, July 14, 2007 5:30 AM> > Subject: Re: TEST - Integrated Collaborative TRAUMA/Disaster Network> >> >> >> Test works> >>> >> ---------- Original Message ----------------------------------> >> De: "Pedro Gustavo Teixeira" <pedrogus at gmail.com>> >> Respondre a: "Trauma & Critical Care mailing list"> >> <trauma-list at trauma.org>> >> Data: Fri, 13 Jul 2007 11:21:03 -0700> >>> >>> TEST WORKS> >>>> >>> On 7/12/07, KMATTOX at aol.com <KMATTOX at aol.com> wrote:> >>>>> >>>> My dear friends and colleagues on this list server.> >>>>> >>>> This vehicle is extremely valuable method of us clinically and> >>>> managerially> >>>> communicating with each other during time of need. We all used this> >>>> communication mechanism to great value during the Katrina/Rita> >>>> Disaster.> >>>>> >>>> It is entirely possible that sometime in the future (let us hope and> >>>> pray> >>>> that it is in the many year future) we may need to use this mechanism to> >>>> ask for> >>>> help, to signal problems and danger, and to professionally exchange> >>>> clinical> >>>> information. Such a need could also be within the week.> >>>>> >>>> I would ask EACH OF YOU to merely hit the reply button and state,> >>>> TEST WORKS> >>>> to document that you are in and are part of this INTEGRATED> >>>> COLLABORATIVE> >>>> NETWORK. If it works during a TEST, then it will work during times> >>>> of> >>>> need.> >>>>> >>>>> >>>> Please - this is like a disaster drill. Let us check our ability to> >>>> LINK..............> >>>>> >>>> Kenneth L. Mattox, MD> >>>> Houston> >>>>> >>>>> >>>>> >>>> ************************************** Get a sneak peak of the all-new> >>>> AOL> >>>> at> >>>> http://discover.aol.com/memed/aolcom30tour> >>>> --> >>>> trauma-list : TRAUMA.ORG> >>>> To change your settings or unsubscribe visit:> >>>> http://www.trauma.org/index.php?/community/> >>>>> >>>> >>>> >>>> >>> --> >>> Pedro Teixeira, MD> >>> Research Fellow> >>> University of Southern California - Keck School of Medicine> >>> Department of Surgery - Division of Trauma and Surgical Critical Care> >>> 1200 North State Street, Room 10-750> >>> Los Angeles, California 90033-4525> >>>> >>> Tel: (323) 226-8112> >>> Fax: (323) 226-8116> >>> --> >>> trauma-list : TRAUMA.ORG> >>> To change your settings or unsubscribe visit:> >>> http://www.trauma.org/index.php?/community/> >>>> >>> >>> >> >> > ------------------------------> >> > Message: 2> > Date: Sun, 5 Aug 2007 17:56:32 -0700 (PDT)> > From: Mike Smertka <medic0947969 at yahoo.com>> > Subject: pressors in trauma, wasn't the world once flat?> > To: "Trauma &amp, Critical Care mailing list" <trauma-list at trauma.org>> > Message-ID: <797191.10692.qm at web61119.mail.yahoo.com>> > Content-Type: text/plain; charset=iso-8859-1> >> > Thanks everyone for the replies to my earlier questions on > > theraputically reduced SBP.> >> > Prior to signing up for this list I raised the question about > > using pressors in trauma and to say I was met with resistence would > > be a kind understatement. But here is my madness.> >> > Pressors are used all the time in trauma, but nobody realizes it. > > How often in the OR or while sutering is epi used to constrict > > vasculature to help control bleeding? It seems to me, all the time. > > I would stipulate that cutting or suturing causes trauma. Maybe a > > controlled trauma or over a small area. But still a pressor used for > > bleeding control. (not to raise CVP)> >> > Now it was brought up on this list to use vasopressin. Stepping > > away from the TBI for a second, from cardiogenic shock of > > nontraumatic origin to spinal trauma, pressors are indicated; If not > > to aid in perfusion, then for what? I understand the dogma of no > > pressors comes from the idea that the pressor does not help CVP and > > therefore is contraindicated because the increase in BP gives a > > false impression of tissue perfusion. But from a common sense point > > of view, back to TBI, you are not trying to raise CVP, you are > > trying to raise MAP. So why would the pressor not work? Unfortunatly > > I don't know the answers to the following questions. Please can > > anyone tell me:> >> > Which pressor? Why vasopresson over levofed or any other? > > Obviously some work differently than others, but I do not know why > > the focus is on Vasopressin.> >> > What doses are being considered and why? It seems to me using 40 > > units of vasopressin might be too much on a pt with a pulse, but > > what is the reasoning for the dose being used or is it titrated to > > effect?> >> > The other side of the coin is by raising MAP with a pressor do you > > impact CVP? Are any other organs or systems negatively impacted? > > i.e. the kidneys?> >> > Does this idea simply come from the idea that in a cold, > > diaphoretic patient we might look at the BP reading and forget we > > treat patients not monitors?> >> > Thanks for taking time to consider this.> >> > Mike> >> > KMATTOX at aol.com wrote:> >> > In a message dated 8/5/2007 4:30:51 P.M. Central Daylight Time, ih7 at msn.com> > writes:> >> > if the ICP is increased, you need to keep the MAP 60 mm higher so the blood> > flows forward through the brain> >> >> > I would agree with that, but would plead that it is NOT crystalloid fluids> > which should be used to achieve that MAP. Remember that most of the studies> > of the past 30-40 yrs were in patients that had 3 liters (or more) challenge> > of crystalloid prior to any surgeon, especially neurosurgeon, seeing them.> > The ICP increase is a complex compartment syndrome and much of our> > traditional urban legend therapy actually iatrogenicly contributed > > to the spiraling> > increase in ICP.> >> > I am delighted to see the direction of the discussions on this web site, and> > do believe that it is going to lead to a whole new wave of research.> >> > k> >> >> >> > ************************************** Get a sneak peek of the all-new AOL at> > http://discover.aol.com/memed/aolcom30tour> > --> > trauma-list : TRAUMA.ORG> > To change your settings or unsubscribe visit:> > http://www.trauma.org/index.php?/community/> >> >> >> > ---------------------------------> > Be a better Heartthrob. Get better relationship answers from someone > > who knows.> > Yahoo! Answers - Check it out.> >> > ------------------------------> >> > Message: 3> > Date: Sun, 5 Aug 2007 19:08:53 -0700> > From: IVAN HRONEK <ih7 at msn.com>> > Subject: Why are crystalloids better > pressors ?> > To: "Trauma &amp; Critical Care mailing list" <trauma-list at trauma.org>> > Message-ID: <BAY141-W9B241682FAA22DC089692F3E50 at phx.gbl>> > Content-Type: text/plain; charset="iso-8859-1"> >> > Let me try to reply to keep the ball rolling:> >> > The way I look at it is the pressors would save administration of > > crystalloid, espec. beneficial in TBI e.g.> > You're right, in some of the animal studies they did decrease > > perfusion/cardiac output. The idea is to follow the "delayed > > resuscitation philosophy" with keeping the crystalloid volume low > > prior to control of bleeding.> >> > Which pressor: again, you're right: one animal study compared > > phenylephrine to vasopressine and got similar results. Levophed also > > did similar job. One difference is the effect on the heart - > > Levophed has some beta 1 effect and may cause more tachycardia than > > appropriate. Phenylephrine and Vasopressine are pure > > vasoconstrictors and so fulfil this role best. A lot of studies have > > been done with Vasopressine and so it is better known and can be > > used in follow-up human studies easier.> >> > Vasopressin dose: 40 U is the CPR dose, right. I agree with you > > Mike, again, I can't see myself shooting a big blous dose to a > > patient without starting with smaller doses and yes, I think > > titration to effect is best, definitely, as with perhaps any drug.> >> > CVP: yes, most vasoconstrictors also squeeze the large veins, but I > > think this would be a transient effect.> > The kidneys are more affected by hypotension as GF is entirely > > dependent on the filtration pressure. Once you raise the BP, urine > > stats flowing again, like it has been shown with Levophed before. We > > are talking short-time use here, prior to control of bleeding and > > transfusion, which are the definitive therapy. A more common > > complication is skin ischemia, I saw digital ischemia in a pt. who > > was on it for > 7 days, splanchnic ischemia has also been shown to > > exist in the animal studies.> >> > Where the idea comes from: I think saving crystalloids, when I see > > myself giving > 10 L of crystalloid and see the anasarca hapenning > > in front of my eyes, I start hating myself. I agree with you once > > again - the BP is not a good diagnostic endpoint, CO is better, SvO2 > > better still, as is acidosis or lactate, however people say these > > all are general and not regional (e.g. brain or kidney ischemia) > > monitors. If you mean to say that pts. with an OK BP can be in deep > > trouble, I agree.> >> > I think here we would be trying to temporize and hope the kidneys, > > the muscles, skin and the splanchnic organs can take some temporary > > ischemia from the vasoconstriction due to the hemorr. shock as well > > as to that due to the vasopressor and we would keep perfusing the > > brain and the heart, that's what the body does by itself in these > > situations anyway.> >> > What I don't understand is why crystalloids help - they do not > > increase oxygen delivery meaningfully..> > but they keep the BP and CO, - is that useful for the body ?? Why ?> >> > What if we just keep up the BP and not the CO - by using pressors ?? > > (now I am questioning the dogma).> > Would patients become more acidotic and have low SvO2 more than with > > crystalloids ?> >> > Thanks also for considering my question, yours, Ivan> >> >> >> >> >> Date: Sun, 5 Aug 2007 17:56:32 -0700> From: medic0947969 at yahoo.com> > >> To: trauma-list at trauma.org> Subject: pressors in trauma, wasn't > >> the world once flat?> > Thanks everyone for the replies to my > >> earlier questions on theraputically reduced SBP.> > Prior to > >> signing up for this list I raised the question about using > >> pressors in trauma and to say I was met with resistence would be a > >> kind understatement. But here is my madness.> > Pressors are used > >> all the time in trauma, but nobody realizes it. How often in the > >> OR or while sutering is epi used to constrict vasculature to help > >> control bleeding? It seems to me, all the time. I would stipulate > >> that cutting or suturing causes trauma. Maybe a controlled trauma > >> or over a small area. But still a pressor used for bleeding > >> control. (not to raise CVP)> > Now it was brought up on this list > >> to use vasopressin. Stepping away from the TBI for a second, from > >> cardiogenic shock of nontraumatic origin to spinal trauma, pressors > >> are indicated; If> > not to aid in perfusion, then for what? I understand the dogma of > > no pressors comes from the idea that the pressor does not help CVP > > and therefore is contraindicated because the increase in BP gives a > > false impression of tissue perfusion. But from a common sense point > > of view, back to TBI, you are not trying to raise CVP, you are > > trying to raise MAP. So why would the pressor not work? Unfortunatly > > I don't know the answers to the following questions. Please can > > anyone tell me: > > Which pressor? Why vasopresson over levofed or > > any other? Obviously some work differently than others, but I do not > > know why the focus is on Vasopressin.> > What doses are being > > considered and why? It seems to me using 40 units of vasopressin > > might be too much on a pt with a pulse, but what is the reasoning > > for the dose being used or is it titrated to effect? > > The other > > side of the coin is by raising MAP with a pressor do you impact CVP? > > Are any other organs or systems negatively impacted? i.e. t> > he kidneys?> > Does this idea simply come from the idea that in a > > cold, diaphoretic patient we might look at the BP reading and forget > > we treat patients not monitors?> > Thanks for taking time to > > consider this.> > Mike> > KMATTOX at aol.com wrote:> > In a message > > dated 8/5/2007 4:30:51 P.M. Central Daylight Time, ih7 at msn.com > > > writes:> > if the ICP is increased, you need to keep the MAP 60 mm > > higher so the blood > flows forward through the brain> > > I would > > agree with that, but would plead that it is NOT crystalloid fluids > > > which should be used to achieve that MAP. Remember that most of the > > studies > of the past 30-40 yrs were in patients that had 3 liters > > (or more) challenge > of crystalloid prior to any surgeon, > > especially neurosurgeon, seeing them. > The ICP increase is a > > complex compartment syndrome and much of our > traditional urban > > legend therapy actually iatrogenicly contributed to the spiraling > > > increase in ICP. > > I am delighted to see the direction of the > > discuss> > ions on this web site, and > do believe that it is going to lead to > > a whole new wave of research. > > k> > > > > > ************************************** Get a sneak peek of the > > all-new AOL at > http://discover.aol.com/memed/aolcom30tour> --> > > trauma-list : TRAUMA.ORG> To change your settings or unsubscribe > > visit:> http://www.trauma.org/index.php?/community/> > > > > > ---------------------------------> Be a better Heartthrob. Get > > better relationship answers from someone who knows.> Yahoo! Answers > > - Check it out. > --> trauma-list : TRAUMA.ORG> To change your > > settings or unsubscribe visit:> > > http://www.trauma.org/index.php?/community/> >> > ------------------------------> >> > Message: 4> > Date: Sun, 5 Aug 2007 22:21:25 EDT> > From: KMATTOX at aol.com> > Subject: Re: Why are crystalloids better > pressors ?= NEITHER> > To: trauma-list at trauma.org> > Message-ID: <c42.1765ab53.33e7dfa5 at aol.com>> > Content-Type: text/plain; charset="US-ASCII"> >> >> > In a message dated 8/5/2007 9:12:31 P.M. Central Daylight Time, ih7 at msn.com> > writes:> >> > What I don't understand is why crystalloids help - they do not increase> > oxygen delivery meaningfully..> > but they keep the BP and CO, - is that useful for the body ?? Why ?> >> > What if we just keep up the BP and not the CO - by using pressors ?? (now I> > am questioning the dogma).> > Would patients become more acidotic and have low SvO2 more than with> > crystalloids ?> >> >> >> >> > The BIG fallacy here is that we continue to assume that CO and BP are our> > objective of resuscitation. WRONG. Whether it be brain, kidney, > > gut, or big> > toe preservation, it is perfusion and oxygen extraction that is essential,> > with variables of temperature, pH, etc. altering the exchange. > > That is why> > NIR would be much better than the BP cuff. Whether it is MAST, drugs,> > crystalloids, or position, any attempt to resuscitate based on BP as an end> > point simply is living in the 1960s and not the 21st century. Get your> > head out of the past and into current thinking. You need to go no > > further than> > Karim Brohi's trauma.org pages to get an excellent review of this subject.> >> > k> >> >> >> > ************************************** Get a sneak peek of the all-new AOL at> > http://discover.aol.com/memed/aolcom30tour> >> >> > ------------------------------> >> > Message: 5> > Date: Sun, 5 Aug 2007 22:28:45 -0500> > From: "Alex Garbino" <agarbino at gmail.com>> > Subject: Re: Why are crystalloids better > pressors ?= NEITHER> > To: "Trauma &amp, Critical Care mailing list" <trauma-list at trauma.org>> > Message-ID:> > <4cf37ad00708052028v5cbe794v6f3edbd5300b2f24 at mail.gmail.com>> > Content-Type: text/plain; charset=ISO-8859-1> >> > As you look at the new techniques to monitor perfusion (NIR instead of BP,> > etc), I would also look at some of the new work regarding slow reperfusion> > protocols. Remember that it's not so much the lack of oxygen as much as the> > sudden onrush of oxygen after deprivation that causes cell death (mostly via> > free radicals, etc). These protocols are being intensely researched in> > cardiovascular events, etc.; but I think this would apply to trauma, TBIs,> > and any other state where tissue is exposed to hypoxia. Maybe in the future> > patients will undergo permissive hypotension and slow reperfusion as opposed> > to today's immediate massive reperfusion, 100% O2 masks, etc.> >> > Alex Garbino> >> > On 8/5/07, KMATTOX at aol.com <KMATTOX at aol.com> wrote:> >>> >>> >> In a message dated 8/5/2007 9:12:31 P.M. Central Daylight Time,> >> ih7 at msn.com> >> writes:> >>> >> What I don't understand is why crystalloids help - they do not increase> >> oxygen delivery meaningfully..> >> but they keep the BP and CO, - is that useful for the body ?? Why ?> >>> >> What if we just keep up the BP and not the CO - by using pressors> >> ?? (now I> >> am questioning the dogma).> >> Would patients become more acidotic and have low SvO2 more than with> >> crystalloids ?> >>> >>> >>> >>> >> The BIG fallacy here is that we continue to assume that CO and BP are our> >> objective of resuscitation. WRONG. Whether it be brain, kidney, gut,> >> or big> >> toe preservation, it is perfusion and oxygen extraction that is> >> essential,> >> with variables of temperature, pH, etc. altering the exchange. That> >> is why> >> NIR would be much better than the BP cuff. Whether it is MAST, drugs,> >> crystalloids, or position, any attempt to resuscitate based on BP as an> >> end> >> point simply is living in the 1960s and not the 21st> >> century. Get your> >> head out of the past and into current thinking. You need to go no> >> further than> >> Karim Brohi's trauma.org pages to get an excellent review of this> >> subject.> >>> >> k> >>> >>> >>> >> ************************************** Get a sneak peek of the all-new AOL> >> at> >> http://discover.aol.com/memed/aolcom30tour> >> --> >> trauma-list : TRAUMA.ORG> >> To change your settings or unsubscribe visit:> >> http://www.trauma.org/index.php?/community/> >>> >> >> > ------------------------------> >> > Message: 6> > Date: Mon, 6 Aug 2007 01:31:23 -0400> > From: "Andrew J Bowman" <andrewj.bowman at gmail.com>> > Subject: Bullet Removal> > To: "Trauma &amp, Critical Care mailing list" <trauma-list at trauma.org>> > Message-ID:> > <dfe364720708052231g36ac1a70saa1c2b21933ed92e at mail.gmail.com>> > Content-Type: text/plain; charset=ISO-8859-1> >> > I was reading some of the recent postings at trauma.org website.> >> > There was one posting about the retro-aortic bullet that was left in place.> >> > Is there ever a concern about eventual erosion of the bullet into the nearby> > vascular structures?> >> > I had a patient in my past who had suffered a GSW in his youth. He presented> > to my ER late at night with abdominal pain and hypotension. CT showed> > massive hemoperitoneum.> >> > OR showed that bullet had eroded into the IVC.> >> > Thanks,> >> > Andrew Bowman> >> >> > ------------------------------> >> > --> > trauma-list : TRAUMA.ORG> > To change your settings or unsubscribe visit:> > http://www.trauma.org/index.php?/community/> >> > End of trauma-list Digest, Vol 50, Issue 12> > *******************************************> >> > > --> trauma-list : TRAUMA.ORG> To change your settings or unsubscribe visit:> http://www.trauma.org/index.php?/community/

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? Fake incr.of CO & BP with crystalloids ? treating the MD/RN only ?