How to Find the MAP with a VAD??

ukstudent · Nov 7, 2007

I am not understanding what the number 78 is. Is this the SBP or heart rate? If you are doing blood pressures by doppler only, what was the DBP? I think that if you can't get a blood pressure any other way than by doppler, then the pt should be in an ICU with an A-line. The SBP and DPB should be close together with a LVAD, often within 10-15 points of each other.

MAP = 1 SBP+ 2 DBP / 3

LauraMT · Nov 7, 2007

It's pretty common for our vads to only have sbp (that's the 78). Heart rate was 103). I don't know why this is. Our orientation was more technical than anything else--how to work the actual hardware and very lacking on assessment. As I understand it most of them never have a diastolic. So (78 + 0x2)/3=26--which is not right but is what our computer claimed it was. Our VADs are out of the CICU in 2 weeks and home as soon as their education is complete unless there are complications. It's overwhelming to me! Ive only been a nurse 4 months.

ukstudent · Nov 7, 2007

I haven't had my VAD class yet. So this is going on what was taught to me by my preceptor. The heartmate II works not on a pump but by rotation. This means that there is no major difference between the SBP and the DBP. If you cannot get the DBP it is probably because it is within a few numbers. So in your pt. SBP is 78, DBP is 78, MAP is 78. The blood is being pushed around at an almost constant pressure. The DBP is never 0 with an LVAD. When we have pt's with LVADs and they have A-lines the MAP is always within a few numbers of the SBP. So in a way your co-workers are correct, use the SBP as the MAP.

LauraMT · Nov 7, 2007

Thanks! That makes more sense. I know the dbp isn't 0 but that's how they have us put it in the computer with our charting system.

Ruby Vee, BSN · Nov 7, 2007

i had my very first vad last night. it was a heartmate ii. anyway, her pressures were by doppler only. it was 78/doppler, which was normal for her. the nurses on my floor all say that that is what you use for the map for our vads too. i work on the acu so we don't have the line like they do in the cicu. i know how to estimate map and it would be like 26 if you followed that rule, which is definitely not right. but is the way we did it right? we had an 8 hour vad class and would you beleive they did not address this?? i can change a controller or battery with my eyes shut, but i can't figure out the map!
the pt was very stable and just sleeping, but i was still incredibly stressed out. the charge asked for lcd volunteers and my hand shot up so i really only had a vad for 4 hours. next time will be better, especially if i can get a dang map! our main transplant/vad surgeon is terrifying so you don't want to screw anything up (of course mostly you want to provide excellent care above all else, but not being screamed at is good too). once a year he apologizes for the abuse in a blanket statement, but he really should apologize daily.
i work again friday and we'll have 4 vads on the floor so i'm getting at least one! please answer fast!!

heartmate iis do not have pulsitile flow, so whatever number you get with a doppler is probably real close to your map. map=(1 systolic + 2 diastolic)/3. if systolic and diastolic are both 78 (or right around thre) that's your map.

vad classes can't possibly address everything you need to know in just 8 hours! i know -- i've taught them.

firstyearRN · Nov 23, 2010

how exactly do we use a doppler to find bp and map??? new to dopplers - please advise. Thank you.