Map?

ZASHAGALKA, RN · Jul 15, 2006

Ok, I'm gonna feel like an idiot asking this considering how far along I am already in school but... Guess this is a good place to ask those "dumb" questions, huh?
What's the significance of the mean arterial pressure-MAP?
What's good? or normal? And does "good" or "normal" depend on what's going on with the patient?
Does a bad MAP make you think about certain systems? Obviously cardio but... What does a low MAP make you think about specifically?
I've caught on that some drugs are titrated to keep the MAP above a certain number but... That's all I've got right now. :uhoh21:
I would REALLY appreciate any help.
Thanks!

You want to see better than 60.

Less than 60 is an indication that vital organs aren't being adequately perfused. This can lead to 'multi-organ failure' - a significant cause of death, the leading cause of death in critical care units.

MAP is going to become the 'gold standard'. In 10 yrs, you will quote MAPs to docs.

Wanna know why? Because we are letting machines NIBPs calculate most of our blood pressures now.

YOU listen for korotkoff sounds that indicate the high of systole and the low of diastole. Then, you 'calculate' MAP. The machines use oscillometric measure of MAP and calculate sys/dia. So, if you are using a machine to calculate BPs, the MAP is the MOST reliable measurement as it is the only 'direct' measure made by a machine.

Also, the MAP is a better indicator of overall perfusion.

~faith,

Timothy.

cardiac.cure03 · Jul 15, 2006

Thanks!

And I just realized I meant to put this in the nursing student forum.

"More fingers pointing at me"

:chair:

summerland5 · Jul 15, 2006

thanks for the expert advice-i'm just a student now, but i have taken note, and i'll remember this post

:kiss

ZASHAGALKA, RN · Jul 16, 2006

I posted this awhile back on another thread:

Warning: Long and technical - but interesting.

These days, when dr's ask me for B/P, they normally want the systolic.

Ex: 'What's her b/p?", "110".

In 10 yrs, we'll all be using mean arterial pressure (MAP). The Mean is the 'average' pressure of the system as opposed to sys/dia, which are the high and low of the system.

Hint: I'm using the terms MAP and 'Mean' interchangeably.

MAP = Sys +(Dia x2)/3 or also, Dia + (Sys-Dia/3).

Or, to use both formulas:

Ex 120/80 = Sys 120 + (Dia x2) 160 = 280/3 = 93.3

or

120/80 = 80 + (120-80 = 40/3) = 13.3 +80 = 93.3

A mean is a better indicator than the high and low. But that being the case, an accurate diastolic is even MORE important, because it will affect the mean.

You might be interested to know that when you manually ascultate BP, you find the high and the low (sys/dia) and then calculate the mean (MAP) - see above.

When a non-invasive b/p machine (NIBP) takes a b/p, it uses an oscillometric method of finding the MAP (or rather, the 'pulse envelope' surrounding the MAP), and then uses a formula/algorithm to calculate the high and the low (sys/dia) from the mean.

But the take home point is this: the mean better seats the 'pulse envelope' of a blood pressure than its outlier values (sys and dia). What this means in English is that MAP is a better and more predictable and reliable indicator of a B/P's ability to get blood to the the right organs. And so, it is in the process of becoming the standard measurement. What it also means is that, while the sys/dia is a more reliable value w/ ascultation (because they are measured and the mean is calculated), the MAP is a more reliable machine value (because the MAP is measured and the sys/dia are calculated).

And you might also be interested to know that the gold standard for an acceptable MAP that reliably 'perfuses' vital organs is a minimum of 60.

From a manual:

"When the NIBP method is the source for determining BP, the Oscillometric method is used. This method measures the pressure pulse within the cuff in incremental steps and has a maximum value of approximately 1 mmHg, which occurs at the MAP. A sophisticated algorithm is then applied to plot the Oscillometric Envelope of pulse pressure measurements vs. cuff pressure measurements. This oscillometric envelope is used to determine the MAP, SBP and DBP values.

The shape of an actual patient Oscillometric Envelope varies from measurement-to-measurement and from individual-to-individual. Therefore, it is quite possible to have different systolic and diastolic pressures for the same measured MAP, as well as different MAPs for the same systolic and diastolic pressures."

~faith,

Timothy.

LilRedRN1973 · Jul 16, 2006

I know many of our physicians have stopped using "keep SBP above 90" when ordering titrable drugs such as Neo/Dopamine/Levo. They now give us orders that read "Keep MAP > 60. The kidneys are especially vulnerable to changes in blood pressure and become very finicky when the MAP is decreased.

Melanie = )

tridil2000, MSN, RN · Jul 16, 2006

I posted this awhile back on another thread:
Warning: Long and technical - but interesting.
These days, when dr's ask me for B/P, they normally want the systolic.
Ex: 'What's her b/p?", "110".
In 10 yrs, we'll all be using mean arterial pressure (MAP). The Mean is the 'average' pressure of the system as opposed to sys/dia, which are the high and low of the system.
Hint: I'm using the terms MAP and 'Mean' interchangeably.
MAP = Sys +(Dia x2)/3 or also, Dia + (Sys-Dia/3).
Or, to use both formulas:
Ex 120/80 = Sys 120 + (Dia x2) 160 = 280/3 = 93.3
or
120/80 = 80 + (120-80 = 40/3) = 13.3 +80 = 93.3
A mean is a better indicator than the high and low. But that being the case, an accurate diastolic is even MORE important, because it will affect the mean.
You might be interested to know that when you manually ascultate BP, you find the high and the low (sys/dia) and then calculate the mean (MAP) - see above.
When a non-invasive b/p machine (NIBP) takes a b/p, it uses an oscillometric method of finding the MAP (or rather, the 'pulse envelope' surrounding the MAP), and then uses a formula/algorithm to calculate the high and the low (sys/dia) from the mean.
But the take home point is this: the mean better seats the 'pulse envelope' of a blood pressure than its outlier values (sys and dia). What this means in English is that MAP is a better and more predictable and reliable indicator of a B/P's ability to get blood to the the right organs. And so, it is in the process of becoming the standard measurement. What it also means is that, while the sys/dia is a more reliable value w/ ascultation (because they are measured and the mean is calculated), the MAP is a more reliable machine value (because the MAP is measured and the sys/dia are calculated).
And you might also be interested to know that the gold standard for an acceptable MAP that reliably 'perfuses' vital organs is a minimum of 60.
From a manual:
"When the NIBP method is the source for determining BP, the Oscillometric method is used. This method measures the pressure pulse within the cuff in incremental steps and has a maximum value of approximately 1 mmHg, which occurs at the MAP. A sophisticated algorithm is then applied to plot the Oscillometric Envelope of pulse pressure measurements vs. cuff pressure measurements. This oscillometric envelope is used to determine the MAP, SBP and DBP values.
The shape of an actual patient Oscillometric Envelope varies from measurement-to-measurement and from individual-to-individual. Therefore, it is quite possible to have different systolic and diastolic pressures for the same measured MAP, as well as different MAPs for the same systolic and diastolic pressures."
~faith,
Timothy.

i agree with everything you said tim. it is really a more reliable number.

also, to the op, in neuro cases the

cpp = map - icp