MAP=60? Why wait to treat?

  1. I am currently working as a student nurse/tech on a SICU at a busy teaching hospital. Was told that patients on the unit should maintain a MAP of at least 60 or above in order to maintain optimal organ perfusion. Wondering why nurses have to wait until the MAP falls to 60 before treating the patient. Doesn't it make sense to start bolusing the patient with fluids as soon as the MAP starts trending down? Is this standard practice or unit specific?
  2. 17 Comments

  3. by   sapphire18
    Our parameters are usually >=60 or 65. Why would you treat something that wasn't a problem?
  4. by   meandragonbrett
    Just because it's trending down doesn't mean it will continue. Why would you treat something that isn't necessarily a problem yet? Bolusing them prematurely could cause more problems that neither you want to deal with nor the patient needs going on.
  5. by   sewnew
    Good points. I thought that 60 was the minimum MAP to keep organs perfused, so anything below that and things start going down hill. Figured it would be better to be proactive and hydrate before this point, but hadn't considered overcompensating. Thanks for the input.
  6. by   8mpg
    Dont forget that when using drugs like Levophed to raise blood pressure takes blood away from other parts of the body. Risk/benefits
  7. by   detroitdano
    Every case is different.

    An anuric end stage renal patient doesn't get rid of any great amount of fluid (insensible losses aside), so anything you give them stays there; you may not necessarily want them to have that fluid.

    Some neuro patients just run low no matter what you do; Florinef, fluids, whatever, they might just live with a MAP of 45. Seen it a billion times.

    They tell you cerebral perfusion pressure should be 70-100 or so. If someone has an ICP of 10 and a MAP of 60, CPP is 50. Sounds like you should be doing something about it, but if they're not broken, don't fix 'em.

    It takes some getting used, not treating a low MAP. In orientation you're taught to flip out over it. Look at the overall picture and then decide if you need to flip out. Are they making urine? Arousable and appropriate? Are they in a deep sleep? The list goes on.
  8. by   Biffbradford
    Right. There's no magic behind the number 60 either. Sometimes you're happy to have a MAP in the 50's, it all depends on the pt and like stated above - risk vs benefit.
  9. by   PetERNurse
    There's no magic behind the number 60 either.
    No magic, just physics. GFR drops significantly at MAP <60mmHg, and CPP is too low to meet O2 demands. They won't instantly go into anuric renal failure or have massive brain death, but you don't want them to stay this way long.
    Remember, you want to treat a patient's physiology, not a number. Monitor trends. If the BP is trending down, maybe it is due to the addition of a new medication, or a dose needs to be adjusted. Is there excessive fluid loss (diarrhea, vomiting, sweating, hemorrhage, etc.). Maybe it is due to ventilator settings (what is the PCO2 trend?). Sometimes it is as simple as changing the patient's position.
    Sounds like you should be doing something about it, but if they're not broken, don't fix 'em.
    We also don't want to have to fix something that is broken. This is why monitoring trends is so important so you can treat a problem (ie: prevent it) before it becomes a problem.
    Depending on the etiology you may be limited with what you can do, and as others said, marginal BP may be acceptable in some patients.
  10. by   fiveofpeep
    Urine Output is an early indicator of ineffective end organ perfusion.

    I also wanted to add that bolusing a patient with a junky heart can cause CHF exacerbation --> respiratory distress.

    When I first started working in ICU, I was bolus happy--especially coming from PACU, but over time you will learn what is really an emergency and in most cases there is often a wait and see approach.

    It's important to look at the big picture (as others have voiced) and think about what is going on with this patient. Are they dry? Do they have a fever? Are they tachycardic? Have they been passing large amounts of dilute urine? Did you recheck the blood pressure?

    Others have given great advice. Best of luck to you
  11. by   cdsga
    Monitoring is what ICU is all about. But just treating numbers is a dangerous thing and can lead to more trouble and worse outcomes and more numbers to treat. So as my experience has taught me and other wise ICU mentors-treat the patient not the numbers. Report trends and start investigating the decline-get a game plan and ward off potential bad outcomes.
  12. by   IHeartDukeCTICU
    Yup and its not just the numbers.... but quality/accuracy of numbers also. Too many inexperienced nurses are quick to "treat" numbers out of the normal range without looking at the bigger picture and the quality/accuracy of numbers. i.e. tx CI <2.0 with known mod/sev TR, dampened waveforms, disease process etc. A number is just that, a number. What's the difference between a MAP of 59 and a MAP of 60? 1-2cm difference in your transducer placement...a dampened waveform from microbubbles in your tubing... ... lots of minute variables that some people forget. It's all about trends, symptoms, & underlying dx

    There are studies out there that demonstrate the harmful effects of treating "false" numbers.
  13. by   NCRNMDM
    I'm a nursing student, but I want to be an ICU nurse when I graduate. This is the way I look at the situation: you should look at all data, and not treat the patient simply based on the MAP (you shouldn't treat the patient based on any number, in fact, it should be based on the numbers plus your assessment and other data). Most ICUs that I know anything about like to keep the MAP at or above 60, ideally. When your patient's MAP is at or above 60, their vital organs (kidneys, brain, etc) are being perfused, and things are as they should be. When the patient's MAP drops below 60, however, you begin to run into some problems. If the MAP drops below 60 and isn't treated, it won't be long until the kidneys decide that they don't want to do their job anymore, and urine production will cease (other bad things will happen, too). Of course, the patient won't instantly go into renal failure or anything terrible as soon as their MAP drops below 60. You don't want to leave it low, nor do you want to fail to intervene, but the patient isn't going to die the instant their MAP hits 59.

    If you see that the patient's MAP is hanging at 60, and you aren't comfortable with that, then look at the other data. What has the BP been like in the past few hours? How's the urine output been? Is the patient tachycardic or is their heart rate WNL? Are you measuring CO? If so, how's the cardiac output been looking lately? Is the patient alert, oriented, awake, and neurologically baseline? If the CO, BP, heart rate, urinary output, and other numbers are WNL (as well as your assessment), then a MAP of 60 isn't really anything you have to worry about. You would want to keep a close eye on the patient, that's for sure, but you wouldn't go running to get a fluid bolus in, or rush to start a vasoactive drip.

    If the patient begins to exhibit signs of a changing or unstable condition (tachycardia, decreased urine output, decreasing BP, decreasing MAP, maybe decrease in the patient's LOC or orientation, etc) then what are you going to do about it? It's good to have a plan of action in mind before the patient goes south. Is this patient a CHF, or heart failure, patient? Do they have preexisting renal failure? Is it safe to administer a fluid bolus or should you skip that and go straight to a vasopressor? As another poster mentioned, end stage renal failure patients aren't removing fluid effectively, so they wouldn't benefit from a fluid bolus as much as a patient with healthy kidneys. In that situation, just as in the situation of a CHF patient, the risk of bolusing might outweigh the benefits.

    Also keep in mind what kind of infusions the patient is getting. Could one of the infusions be affecting the patient's MAP in a negative way? If so, does this infusion need to be stopped, slowed, or changed? Also keep in mind what other issues could cause the MAP to drop. You're in a SICU, so bleeding is a major issue. Most surgical patients are getting heparin, or another anticoagulant, and this only accelerates the bleeding. Has the MAP started dropping suddenly in comparison to where it was an hour ago (or thirty minutes ago)? If so, could this patient be bleeding internally, or at a site that you haven't seen yet? If the MAP is dropping gradually, you need to be a kind of detective. There are a ton of things that could cause this. Is there a medication that could be responsible? Is the CO2 too high? Are the vent settings (as one poster already mentioned) suitable? The list goes on and on, and it's up to you to investigate and discover the cause.

    Treating a MAP that is sustaining the patient at a stable state could be more harmful than beneficial. Bolusing a patient (especially an end stage renal failure or CHF patient) could lead to hypervolemia and pulmonary edema. Starting a vasoactive drip could cause tachycardia, arrhythmia, or result in blood being shunted from other parts of the body (as one poster already mentioned). In these situations you really have to assess the situation and not treat based on just one number. Another key thing to keep in mind is the patient's baseline BP before admission. If your patient's blood pressure runs low at baseline, then they can get by with a lower MAP. If, however, your patient is chronically hypertensive, then their MAP shouldn't be allowed to get as low as the patient who is normotensive (or even hypotensive) at baseline. There are a lot of factors that come into play, but the most important thing you can do is assess and remain calm. Don't be quick to bolus the patient, or add a vasopressor when you don't need to. Use your head, look at the trends, continue to monitor the patient, assess the patient's baseline vitals, and then make a decision.
  14. by   fiveofpeep
    Quote from mattrnstudent23
    I'm a nursing student, but
    Tip: Stop beginning your posts with "I'm a student." I would never know otherwise and I know it's bad, but I automatically don't want to keep reading because of it.

    Edit: I forced myself to read your gigantic post and it sounds like you will be a great ICU nurse. You're on the right track with asking a lot of smart questions about the situation and being prepared.

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