Mean Arterial Pressure

[eaetaylor]

When working in the ICU, we are always sure to monitor a patient's MAP, and work to keep it above 60 to ensure proper vital organ perfusion. I was wondering why, we as nurses (and doctors) are so wrapped up in only systolic BP? We titrate medicines such as dopamine and neosynephrine based on SBP parameters. I was wondering why diastolic pressures are not thought of as importantly? When calculating a MAP, I found that a BP of 120/80 gives a MAP of 93.3 mmHg. If the systolic is changed by 10 to a BP of 130/80, the MAP changes to 96.7 mmHg. BUT, if the diastolic is changed by 10, to 120/90 the MAP changes to 100.0 mmHg.

It only seems logical to me that we should be equally concerned with keeping their diastolic pressure up as their systolic. Am I missing something? I'm fairly new, so any education would be helpful.

Thanks!

[NotReady4PrimeTime, RN]

No, definitely not that simple. Is anything in nursing??

Interesting how we all practice differently, huh?

You said a mouthful there! I work in a pediatric cardiovascular ICU and sometimes our docs (well, one in particular) will give us SBP, DBP and MAP parameters that are physiologically impossible to meet for our neonates. You might get the SBP and DBP in range, but the MAP is low, or you might have the SBP and MAP in range but the DBP is low. So we always have to clarify which of them is the most important. And of course when he hands off to the night doc, it all changes anyway.

[ghillbert, MSN, NP]

No, definitely not that simple. Is anything in nursing??

We just tend to do it this way. Most of the time, of course not all of the time, in our CVICU we pay little attention to DBP. Some CV surgeons completely ignore it. And nine times out of ten, when you call on a SBP in 80's, they'll ask what your MAP is. If it's >60, they're fine with it. Same goes if you call with a MAP >80, they want to know what your SBP is, and if it's

I'm sure that is true. God knows docs appear to decide treatment based upon preferences rather than evidence at times...!

The only thing that worries me is that people get used to that trend and forget why you have to worry about each separate component in various disease processes.

[nrsang97, BSN, RN]

We titrate by MAP and SBP. I work neuro so we may do things a little differently. Mostly titrate for instance MAP 100-130 in vasospasam patients.

[registeredin06]

The only thing that worries me is that people get used to that trend and forget why you have to worry about each separate component in various disease processes.

good point, ghillbert.