Intraoperative volume assesment

Discussion in 'Anesthesiology' started by snowman8, Dec 7, 2008.

  1. snowman8

    snowman8 ASA Member
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    How do you assess your patient's intraoperative volume status?

    Are you using CVP or PCWP?

    What tools are you using to assess whether your patient in responsive to a volume challenge,( i.e. increase in stroke volume)? Are you using a change in CVP?

    Do you use a conservative vs liberal volume replacement model? How do you feel that this affects patient outcome?

    I would like to hear everyone's opinions and techniques and will follow with some current literature on the topic.

    BRING IT!
     
  2. dhb

    dhb Member
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    Proven to be useless.
    Pulse presusre delta is the only reliable mesure.
     
  3. Mman

    Mman Senior Member
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    The only reliable measure?

    I believe there is more evidence supporting esophageal doppler than pulse pressure variation as a measure of recruitable stroke work (or volume responsiveness or whatever you want to call it).

    Heck, as long as we are at it, TEE is the gold standard and more reliable than anything else you are going to use.

    As for the OP, conservative vs liberal fluid replacement strategies are inherently flawed. The goal is for the ideal replacement and not too much or too little. Give the right amount of fluid at the right time to help improve patient outcomes.
     
  4. snowman8

    snowman8 ASA Member
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    Ahhh, now you see where I'm getting at. What is your guide for what is too much or too little. Urine output, HR, BP? Until recently change in CVP and other pressure measurements were used to assess ones "volume status" and response to a "fluid challenge". Now there is literature on pulse pressure change or systolic pressure change up and down. Also, like mentioned, esophageal doppler.

    How do you assess what part of the Starling curve you are on? I mean, that is what we are really asking.

    In the end, our goal is to optimize O2 delivery. We shouldn't have to place a PAC to measure SV and CO in all our patients. I know there are less invasive devices to do this, PICCO but few have access to this. Also one that uses just an a-line, but not as much literature.

    In simple cases and in healthy patients, I don't think plus or minus a couple liters matters that much. On the other hand, for a 6-8 hour whipple or a patient with end-stage organ disease I think fluid management can really alter patient outcome.

    What are all you guys using for your big belly case, esophagectomy, big spine or maybe your pneumonectomy to guide your fluid management? Are you just guessing based of the response to BP, HR and Urine output. Is that good enough? I mean if you think about it, after inducing anesthesia and providing analgesia so our patients wake up comfortably, what do we do 90% of the time. We give IVF to "resuscitate" our patients.

    At HSS in NY, for total hips, one attending uses an epidural to induce normovolemic hypotention to decrease blood loss. He keeps MAPS around 45-55. HE then augments CO with an epi gtts and uses this noninvasive device to follow hemodynamic variables(it uses a BP cuff that gathers several measurements that allows him to determine CO, SVR, ect..). He use to use a PAC before he used this new noninvasive device. He then places a nasal canula on the patient and gives sedation with a propofol gtts.

    Besides decreasing blood loss (which in the end it might be an average of 500ml) and transfusion, he has been able to decrease overall morbidity and mortality. I believe it is because he is able to optimize in O2 delivery and fluid management. Not sure if the neuroaxial technique has something to do with it too. I'm sure it does.

    I'm not saying this is this best way to provide anesthesia for a THR, but I'm trying to figure out what is the best way to guide and deliver fluids for our cases where it really can alter patient outcome.
     
  5. Jeff05

    Jeff05 Senior Member
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    "best way...to affect pt outcome"

    this is THE ISSUE. no one really knows what's best. emerging evidence suggests that flooding the patient with a preset ml/hr as was/is currently done may not be the best.

    keeping patients too dry - decreased BP -> organ hypoperfusion is also not great.

    this is a topic of great controversy, at this time i do not believe there is ANY consensus on the topic.

    as far as floating a swan for total hips, that's shady. unless you have to aggressively manage Pa pressures, it's not warranted. then again, i hear they put a lines for all spinal anesthetics at HSS, just a rumor, but that's pretty redic. as well.
     
  6. Planktonmd

    Moderator Emeritus Lifetime Donor Classifieds Approved 10+ Year Member

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    There is really no magic solution here.
    The best fluid management strategy varies for each specific case and depends significantly on your clinical judgment and your ability to use the available data.
    The more experienced you are the less likely you will need exotic monitoring techniques to figure out a fluid management plan.
     
  7. seinfeld

    seinfeld ASA Member
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    This is a topic which have emerging evidence i would suggest thoughtful review of the literature, i have spent hours, formulated my own opinions, and in the end they are just opinions. What i can tell you is that the emerging consensus is that the old 10/8/6 and 4:2:1 rules are outdated and will lead to worse outcome for GI surgery/ Thoracic surgery. Urine output has been shown time and time again not to be a reliable solitary value on which to base adequacy of fluid replacement or predict postop renal failure especially during laparoscopic surgery. CVP again is useless to predict response to fluid bolus. Less than 5 or greater than 25 gives you ideas of possible fluid responsiveness but if i place a monitor to assess fluid responsiveness its an aline and i use SPV (systolic pressure variation). PA Cath... better to follow trends but if i am really concerned about heart function than i place a TEE.
     
  8. aredoubleyou

    aredoubleyou Senior Member
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    Is it really better clinical judgement or do you think that there is a wide variation of strategies that all work and dont really effect outcome?
     
  9. Planktonmd

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    The bottom line is: Don't give too much but don't give too little either, anything in between is OK.
    Your clinical judgment is what decides what is too much and what is too little for a specific patient.
     
  10. snowman8

    snowman8 ASA Member
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    What are you using to guide how much volume you are giving your pt.....CVP, delta CVP, UO, HR, BP, 4-2-1, 10-8-6 rule, etc.....?

    I know not a big deal is most healthy, 2 hour procedures, but what about in your pt's with multiple co-mordities or longer cases with bleeding or large 3rd space losses?

    No one has given me a good answer bedsides pulse pressure change on aline with PP ventilation or systolic up and down. Even using these variables on standard monitors if difficult to really asses accurately. It is my impression that there are newer monitors with algorithms that gives you these numbers.

    One of the primary roles of the anesthesiologist, volume assesment and recussitation, is very difficult and inaccurate to determine without the use of a PAC to assess stroke volume (CO) and SVo2 in relationship to other standard monitoring.
     
  11. seinfeld

    seinfeld ASA Member
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    good judgement comes from experience, experience comes from poor judgment.....

    In internal medicine they call it clinical suspicion, the same feeling comes in anesthesia. If you think deciding how much IVF to give is hard to wrap your head around, just wait until you do cardiac/ have a bleeding pt and it time to give blood and products. No test will come back soon enough to tell you whether you need platelets, FFP, Cryo factor VII.

    Relax, it takes time to get the feeling of how to do these things and even then you will occasionally get one wrong. Rely on your staff to guide you, ask them why they feel they need it or dont need it and over time youll start getting it.
    names like

    -Brandstrup Annals of Surgery • Volume 238, Number 5, November 2003,
    -An editorial in British Journal of Anaesthesia 97 (6): 755–7 (2006),
    -Holte Annals of Surgery • Volume 240, Number 5, November 2004, Vadim - - Nisanevich, M.D.,Anesthesiology 2005; 103:25–32 Effect of Intraoperative Fluid Management on Outcome after Intraabdominal Surgery
     

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