Mean Arterial Pressure is a value that
is frequently used by Physicians and Paramedics to assess a patient's hemodynamic status. For example, each
organ system requires a certain MAP to adequately perfuse that organ. In
addition to this, the MAP is a number used in other important formulas such as
the Cerebral Perfusion Pressure (CPP) formula.
MAP should not be a foreign concept to EMTs as most of todays hospital and
ambulances use automated blood pressure devices that display the MAP in addition
to the pulse, systolic and diastolic pressures.
The MAP value is fairly easy to calculate. If you double the diastolic
pressure, add the systolic number to it and divide that number by 3 you will
have a very close approximation. Don't worry about minor variations from
automatic devices as they may incorporate a more complicated formula that takes
heart rate into consideration. For most instances in EMS, this is not critical
and does not change the value a great deal.
MAP = [(2*D)+S] / 3