Mean arterial pressure: Difference between revisions
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==Overview== | ==Overview== | ||
The '''mean arterial pressure''' ('''MAP''') is a term used in medicine to describe a notional average [[blood pressure]] in an individual. It is defined as the average arterial pressure during a single [[cardiac cycle]]. | The '''mean arterial pressure''' ('''MAP''') is a term used in medicine to describe a notional average [[blood pressure]] in an individual. It is defined as the average arterial pressure during a single [[cardiac cycle]]. | ||
==Calculation== | ==Calculation== | ||
MAP = (CO x SVR) + CVP, where<ref>[http://www.cvphysiology.com/Blood%20Pressure/BP006.htm Cardiovascular Physiology Concepts: Mean Arterial Pressure, Richard E. Klabunde, Ph.D]</ref> | |||
* | *CO is [[cardiac output]] | ||
* | *SVR is [[systemic vascular resistance]] | ||
* | *CVP is [[central venous pressure]] | ||
CVP is usually small enough to be neglected in this formula. | |||
==Estimation== | ==Estimation== | ||
At normal resting heart rates | At normal resting heart rates MAP can be approximated using the more easily measured [[Systole (medicine)|systolic]] and [[diastolic pressure]]s, SP and DP:<ref>http://www.nda.ox.ac.uk/wfsa/html/u10/u1002_03.htm</ref> | ||
: | :MAP = DP + 1/3 (SP - DP) | ||
or | or | ||
: | :MAP = 2/3 DP + 1/3 SP | ||
MAP = [(2 x diastolic) + systolic] / 3 | :MAP = [(2 x diastolic) + systolic] / 3 | ||
or equivalently | or equivalently | ||
: | :MAP = DP + 1/3 PP | ||
where | where PP is the [[pulse pressure]], SP-DP | ||
At high heart rates | At high heart rates MAP is more closely approximated by the [[arithmetic mean]] of systolic and diastolic pressures because of the change in shape of the arterial pressure pulse.<ref>http://academic.uprm.edu/~mgoyal/fluidsjuly2004/property2004.pdf page l-5 </ref> | ||
==Clinical significance== | ==Clinical significance== | ||
MAP is considered to be the [[perfusion pressure]] seen by [[Organ (anatomy)|organs]] in the body. | |||
It is believed that a | It is believed that a MAP of greater than 60 [[mmHg]] is enough to sustain the organs of the average person under most conditions. | ||
If the | If the MAP falls significantly below this number for an appreciable time, the end organ will not get enough blood flow, and will become [[ischemia|ischemic]]. | ||
== See also == | == See also == | ||
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==References== | ==References== | ||
{{Reflist|2}} | |||
[[de:Mittlerer arterieller Druck]] | [[de:Mittlerer arterieller Druck]] |
Latest revision as of 13:49, 5 March 2015
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
The mean arterial pressure (MAP) is a term used in medicine to describe a notional average blood pressure in an individual. It is defined as the average arterial pressure during a single cardiac cycle.
Calculation
MAP = (CO x SVR) + CVP, where[1]
- CO is cardiac output
- SVR is systemic vascular resistance
- CVP is central venous pressure
CVP is usually small enough to be neglected in this formula.
Estimation
At normal resting heart rates MAP can be approximated using the more easily measured systolic and diastolic pressures, SP and DP:[2]
- MAP = DP + 1/3 (SP - DP)
or
- MAP = 2/3 DP + 1/3 SP
- MAP = [(2 x diastolic) + systolic] / 3
or equivalently
- MAP = DP + 1/3 PP
where PP is the pulse pressure, SP-DP
At high heart rates MAP is more closely approximated by the arithmetic mean of systolic and diastolic pressures because of the change in shape of the arterial pressure pulse.[3]
Clinical significance
MAP is considered to be the perfusion pressure seen by organs in the body.
It is believed that a MAP of greater than 60 mmHg is enough to sustain the organs of the average person under most conditions.
If the MAP falls significantly below this number for an appreciable time, the end organ will not get enough blood flow, and will become ischemic.
See also
References
de:Mittlerer arterieller Druck