Menu Icon Search
Close Search

About the ads

Downside to a VAMP

Discussion in 'Critical Care' started by bryanboling5, 12.26.09.

  1. bryanboling5

    bryanboling5 Member

    Joined:
    10.25.03
    Messages:
    177
    Location:
    Lexington, KY
    SDN 7+ Year Member

    SDN Members don't see this ad. (About Ads)
    I'm an RN in a community Med/Surg/Cardiac ICU and I've got a question about a-lines. I work at night, so our PulmCCM doc is never here to ask.

    We don't get many a-lines, but when we do, they almost never use the VAMP (by Edwards) even though that's what we stock. I work in a CTICU at a sister hospital and all my a-lines have the VAMP. I've been told that our PulmCCM doc "doesn't like them" but I don't know why and never get the chance to ask him. I think they're great because I don't have to waste 10mls of blood with every draw. It seems that they make more sense than the traditional line. Anyone know what the downside might be? Why our PulmCCM doc doesn't like them?

    Not trying to second guess, just trying to learn.
    Thanks!
    Bryan
  2. emergiQ

    emergiQ Killer Whale Trainer

    Joined:
    06.22.08
    Messages:
    78
    Location:
    The Hockey Hall of Fame
    Status:
    Attending Physician
    SDN 5+ Year Member
    Not sure what a VAMP is. Is it the same as a "rosebud"? We use those at one of my institutions, mainly to keep the tracing stable so it doesn't have to always be re-zeroed due to damping, over-damped, etc.

    I think the main downside is just cost. The rosebuds are overpriced for a little piece of damn plastic if you ask me...

    Maybe your pulm doc thinks the cost of 10ml of blood is less. (shrug)
  3. proman

    proman Member Moderator

    Joined:
    03.05.02
    Messages:
    1,857
    Status:
    Attending Physician
    Physician SDN 10+ Year Member
    I think the VAMP is a self contained in-line syringe that allows to draw back 10cc of blood then sample from the a-line with a needle-less device, then return what was formerly wasted. We have something called Safe-T set (or something like that).

    I think they kill a lines. No evidence, just experience (and many 3 am a line re-do).
  4. bryanboling5

    bryanboling5 Member

    Joined:
    10.25.03
    Messages:
    177
    Location:
    Lexington, KY
    SDN 7+ Year Member
    That's what the VAMP does. So, WHY do they kill a-lines? What about them? Is it returning the blood?
  5. proman

    proman Member Moderator

    Joined:
    03.05.02
    Messages:
    1,857
    Status:
    Attending Physician
    Physician SDN 10+ Year Member
    I think it's the negative pressure generated by the syringe.
  6. bryanboling5

    bryanboling5 Member

    Joined:
    10.25.03
    Messages:
    177
    Location:
    Lexington, KY
    SDN 7+ Year Member
    If that's the case, wouldn't using a regular 10ml syringe (which is what we do when we don't have a VAMP) cause the same problems?
  7. proman

    proman Member Moderator

    Joined:
    03.05.02
    Messages:
    1,857
    Status:
    Attending Physician
    Physician SDN 10+ Year Member
    The times I've watched a nurse draw on one of those syringes they pulled it back all the way quickly. That's not how I draw back, it usually takes me about 4-5 seconds to aspirate back. That produces much less negative pressure.

    I also don't throw away the aspirate, but will give it back, usually through the a line or through a venous line (sometimes). I know most nurses won't do that. If you do give back through the a line, it should be at a rate that's slower than 1ml per second. Anything faster and you can have retrograde bolus to the cerebral circulation (bad if there's air or clot).

    Does any of this make a difference? I can't say. My experience is that the units that use the systems have much shorter duration of a lines (sometimes <12 hours). Our cardiac SICU does not routinely use the system and routinely has a lines last several weeks. All of this is just anecdote though.
  8. The right Path

    The right Path Goodbye Cherry Ames

    Joined:
    12.10.09
    Messages:
    540
    Location:
    Nor-Cal
    Status:
    Pre-Medical
    SDN 2+ Year Member
    Can only speak from my hospital regarding vamps.

    I know there are different varieties, but the kind we stock are the inline syringe pull back system.

    Personally, I've never come across any physicians prefering that we don't use them for specimens.

    If you want to know an individual's rationale for preference, you really have to go straight to the source.

    I can throw out some options of why they may prefer the a-line not be used for blood draws.

    1. The rapid return of the "waste" and the flush can cause arterial spasm which can interfere with accuracy of measurement and cause a fling in the waveform, not to mention potentially compromising perfusion.

    2. With the set-up that we use, it is possible to get retrograde blood flow into the transducer which can impair accuracy.

    The points that proman already made are interesting and may be contributing factors. Interesting topic.

    Also, granted, in our units (ICU/NSICU) we typically don't rely heavily on A-lines. Most frequently they are placed by the anesthesiologist during surgery for their own monitoring purposes and they usually don't bother to suture them- which doesn't help it's lifespan.
  9. proman

    proman Member Moderator

    Joined:
    03.05.02
    Messages:
    1,857
    Status:
    Attending Physician
    Physician SDN 10+ Year Member
    I've not heard of this. Why would this happen?

    You seem to think that suturing the line in out prolong the catheter's lifespan. I don't agree. I've had sutured and non-sutured a lines both fail, relatively quickly. I don't see how suture is any better than quality dressing and tape. One thing that does appear to matter is looping the extension tubing around the thumb. Our PICCs are never sutured either.

    Unfortunately none of this stuff has ever been studied, so we don't have more than experience and opinion.
  10. cowboy71

    cowboy71 ASA Member

    Joined:
    01.11.07
    Messages:
    22
    SDN 5+ Year Member
    To keep a-lines patent there is a continuous flow through the catheter based on the pressure head against the transducer. I believe it is around 1ml/hr for each 100mmHg. I don't remember all the details, but there was a presentation at the ASA this year suggesting that failure rates are much lower with at least 3ml/hr flowing through the catheter. The surprising part was that the people presenting this had studied the difference between the pressure on the gauge of the pressure bag and the actual pressure on the transducer and there was a huge variation. Sometimes the gauge would read 400mmHg and there still wasn't 300mmHg on the transducer. This would suggest that keeping a sufficient pressure on the transducer would lower failure rate. I know in many a-lines I replace the pressure bag isn't holding that much pressure constantly and the nurses are too busy to constantly keep watching it.

    The VAMP system may place enough of a resistance in the system to further reduce the flow through the catheter causing increased failure rates.

    Just something to think about and for this reason I suggest putting even more than 300mmHg on the pressure bag.
  11. The right Path

    The right Path Goodbye Cherry Ames

    Joined:
    12.10.09
    Messages:
    540
    Location:
    Nor-Cal
    Status:
    Pre-Medical
    SDN 2+ Year Member

// Share //

Style: SDN Universal