diastolic blood pressures, too low?

  1. Hi! I am a new tele nurse and have only been working a few months. A patient of mine has been getting all her bp meds IV. The dr's have perameters for the sys (hold if sbp < 120, 110 etc.). Being a new grad I was told I could not push metoprolol and the enalaprilat until I was ACLS certified. So I had to rely on other nurses to push these meds.

    Question: My pateint bp was 140/48 (around there) with perameters only for the systolic. The other nurses refused to push the meds because of the diastolic. When is a diastolic too low? My charge said there is never a too low diastolic (figuratively speaking I guess, since nothing would be a little low I think). But what are the rules of thought on this issue? No one ever talked about a low dbp in nursing school.

    Thanks for any input!
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  2. 2 Comments

  3. by   papawjohn
    Hey Chachh

    Your question's been out here a day or two and is starting to look lonesome. Let me try to deal with it.

    To begin with, I'd need to know the rest of your Pt's vitals to really give a good answer. If the BP was taken with an NBP (dynamap) it's been my experience that very fast or slow heart rates affect the accuracy of the BP. So I'd first make sure that YOU were sure that's an accurate BP. (Some of us old people get cranky and particular about things like that.)

    Then I'd congratulate you on being concerned about the Diastolic cause that is the pressure that fills the coronary arteries. THAT's something important about the Diastolic BP, you'll agree. The 'flap' of the Aortic Valve covers up the coronary sinus (that leads into the coronary arteries) during systole and opens during diastole.

    Third, I'd make sure you understand that the most important single number of the BP is neither systolic nor diastolic. It is the MEAN ARTERIAL BP. The systolic only lasts a micro-second; diastolic is quickly elevated by the next heartbeat. But the MAP is the pressure that we use to figure out how the important organs like brain and kidneys are perfused.

    And then I'd say that if you don't have a GOOD reason (other than a sense of alarm at the numbers) to refuse to give it--you ought to follow Dr's orders. If you feel it's just TOO wrong--call him. He'd rather you called him than have a committee meeting of nurses debating about his pt's meds.

    Hope this helps
    Hang in there--it's a great career

    Papaw John
  4. by   chachh
    Quote from papawjohn
    Hey Chachh

    Your question's been out here a day or two and is starting to look lonesome. Let me try to deal with it.

    To begin with, I'd need to know the rest of your Pt's vitals to really give a good answer. If the BP was taken with an NBP (dynamap) it's been my experience that very fast or slow heart rates affect the accuracy of the BP. So I'd first make sure that YOU were sure that's an accurate BP. (Some of us old people get cranky and particular about things like that.)

    Then I'd congratulate you on being concerned about the Diastolic cause that is the pressure that fills the coronary arteries. THAT's something important about the Diastolic BP, you'll agree. The 'flap' of the Aortic Valve covers up the coronary sinus (that leads into the coronary arteries) during systole and opens during diastole.

    Third, I'd make sure you understand that the most important single number of the BP is neither systolic nor diastolic. It is the MEAN ARTERIAL BP. The systolic only lasts a micro-second; diastolic is quickly elevated by the next heartbeat. But the MAP is the pressure that we use to figure out how the important organs like brain and kidneys are perfused.

    And then I'd say that if you don't have a GOOD reason (other than a sense of alarm at the numbers) to refuse to give it--you ought to follow Dr's orders. If you feel it's just TOO wrong--call him. He'd rather you called him than have a committee meeting of nurses debating about his pt's meds.

    Hope this helps
    Hang in there--it's a great career

    Papaw John
    Thankyou so much for your reply! I was thinking no one was answering because either it was a dumb question or they weren't too sure themselves! That pt in particular had been recovering from a cerebral bleed, hr in the 80's with periods of v tach, bp's ranging from the 160-130's/60-40's, DNR, basically comfort measures, npo and gcs 10-12. Getting ready to transfer to hospice.

    You are so right about the MAP! Definitely need to study up more on that (project for tonight). And the next time I worked I was going to start and hit up the Dr's for their input. I work nights so unfortunately never too sure what the Dr is going to gripe about if I call on. I hate being new!!!

    Thanks again!

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