Can anyone explain to me a couple things about CVP?? - page 2

1) First of all, what is so significant about the number? What is a normal number for someone healthy? What does that number mean?? 2) Now, can anyone expalin to me, step-by-step, how to get... Read More

  1. by   ZASHAGALKA
    Quote from raindrop
    Okkkk, I thhink I am getting there. Slowly, but surely. You are helping me out greatly.



    1) HOB Down 9I'm just going to keep it down that is how I see the other nurses do it)

    2) Place stopcock up
    3) Remove cap.

    3) Give a little flush via pigtail

    5) Place transducer at phlebostatic axis

    6) Zero it out

    7) Read.

    Now, how does that look?

    If it looks correct, I want to make a cheat sheet out if it.
    Well we continually monitor CVP, it constantly displays on the monitor. Zero is just maintenance; I wouldn't keep my pt's head down all the time to monitor CVP - it's not necessary. I'm sure there's some rule about how high up it can go, say 30 degrees, but If I'm monitor CVP, my HOB isn't usually up higher than that for other reasons. But I wouldn't keep a pt flat constantly and uncomfortable for this - not necessary.

    of course, also, replace the cap, return the stopcock to middle position and I normally flush another ml into the patient to ensure the line doesn't occlude (theoretically that is what the 3ml/hr delivered by the system and the heparin in the bags we use do).

    ~faith,
    Timothy.
  2. by   raindrop
    I want to kiss you!!



    Now, one last thing...

    It is OK to flush if the cap is off? it is Ok to flush with the stopcock upward?
  3. by   ZASHAGALKA
    Quote from raindrop
    I want to kiss you!!



    Now, one last thing...

    It is OK to flush if the cap is off? it is Ok to flush with the stopcock upward?
    That's what I do. But, that is a circuit to the atmosphere in that position and pulling the pigtail with the cap off and the stopcock up is going to release fluid through the port to the outside (under a tad bit of pressure no less).

    Just make sure the port isn't aimed at you or an electrical outlet when you do it. Especially make sure it isn't aimed at you if there is blood in the port (anesthesia uses those ports in surgery sometimes and can leave traces of blood. Pulling that pigtail with the port open can fling blood contaminated fluid out at you) I normally put a syringe wrapper over the port when I pull (It's sterile on the inside and disposable).

    ~faith,
    Timothy.
  4. by   ZASHAGALKA
    If the CVP is less than 5 (and sometimes higher depending on the patient and the doc), you are probably going to be thinking fluids if the pt's blood pressure is low.

    But this is where balancing the tranducer at the phlebostatic axis is important. It it's too high, it's gonna give you a false low reading; too low and a false high reading.

    If you don't have them ordered PRN, then this would be the time to have a confab w/ a doc.

    Our docs tend to order PRN NS, if that doesn't work, PRN Plasminate, and then progressing to Hespan or just outright Blood.

    Yes?

    ~faith,
    Timothy.
    Last edit by ZASHAGALKA on Sep 26, '05
  5. by   rstewart
    Quote from ZASHAGALKA
    Maybe I was thinking normal ICP readings with the 2-15 number, eh? Sorry, I don't normally 'teach'.

    OK, I'll buy 5-10.

    ~faith,
    Timothy.

    lolol...nope don't buy 5-10 or 2-15. (at least not without specifying the units of measurement as well as method used to obtain.)


    Now as Karen mentioned in an earlier post the normal range for a CVP is 5-10 cm H2O. "Back in the day" we used devices called water manometers to obtain CVP measurements and they were calibrated with markings to give readings in cm H2O.

    Systemic arterial pressures, PA pressures, right ventricular pressures etc are all measured in mm Hg-----so in order to make meaningful comparisons conversions (from cm H2O) were necessary.

    With rare exceptions today critical care nurses measure CVPs using pressure transducer-monitor systems as you have described. Those systems give values which are already converted to mm Hg. Norms vary depending upon which reference book you use but 0-8 mm Hg or so for a CVP is about right.
  6. by   ZASHAGALKA
    I'd buy 5-15 myself. It's my experience that docs treat less than five with fluids/colloids and are not normally concern w/ CVPs at the high end of the range - except to use that number to rule out fluid deficit as a cause of problems.

    CVPs are normally used say, after major surgery or sepsis where circulating volume tend to drop.

    Any number at the lower end in a symptomatic patient is treated. And of course it's fair to mention that CVP is used to calculate SVR and such on the hemo calcs - so the actual number is important.

    I thought the Philips Intellivue, the follow on to the old HPs (and those HPs) display CVP in cm H2O. Now I'm not saying that is true for a fact - cause you know we/I tend to use the number and not carry over the unit. But mmHg for CVP just doesn't sound right. Now I'll have to look.

    I still think I was taught a wider range, 2-15 or something to that effect.

    (edit - I looked up CVP on the Intellivue - it list 2-6mmHg as its normal range for its system. So I stand corrected. From Philips: "When stroke index is low, the CVP helps differentiate right ventricular dysfunction (CVP>6) and hypovolemia (CVP is normal or <2). CVP is right atrial pressure. A reflection of Right Ventricular End Diastolic Pressure. The CVP is an estimation of preload.")

    ~faith,
    Timothy.
    Last edit by ZASHAGALKA on Sep 26, '05
  7. by   rstewart
    Quote from ZASHAGALKA

    (edit - I looked up CVP on the Intellivue - it list 2-6mmHg as its normal range for its system. So I stand corrected. From Philips: "When stroke index is low, the CVP helps differentiate right ventricular dysfunction (CVP>6) and hypovolemia (CVP is normal or <2). CVP is right atrial pressure. A reflection of Right Ventricular End Diastolic Pressure. The CVP is an estimation of preload.")

    ~faith,
    Timothy.

    Correction noted. See if you accept (as you did) Karen's provided norm of 5-10 cm H20, then the top of the range is just over 7 since 1mm Hg=1.36 cm H2O.

    I do sincerely appreciate your willingness to check your initial response for accuracy. To me it demonstrates a genuine interest in learning.
  8. by   Mayflye
    You should check out Mark Hammerschmidt's site: All you ever wanted to know about invasive monitoring and more! http://www.icufaqs.org
  9. by   UTRN2005
    I'm a BSN student graduating in Dec. I took an ICU class over the summer and we were told norm is 2-6. Just wanted to throw in what we were taught, but it looks like you've pretty much got it sorted out.

    The way I would remember which way to turn the stopcock would be that the long end is the closed off side, and that the tubing between the pt and the transducer is the harder one. That way you can stop and think which direction do you want to turn off instead of trying to memorize directions.
  10. by   diapersprinkles
    does the patient have to be disconnected from the mech vent when taking cvp? because i see some nurses practice it and others don't. i once asked what the rationale behind that and i was told that the mech vent increases the cvp reading. i tried looking at the skills manual but there isn't anything mentioned there about disconnecting the patient from the mech vent while reading cvp. please enlighten me on this. thank you very much.

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