Certified Medical Assistant (CMA AAMA)Clinical Workflow and Patient IntakeHard
A patient's blood pressure is measured at 120/80 mmHg. Using the standard formula, what is this patient's mean arterial pressure (MAP)?
- A80 mmHg
- B120 mmHg
- C93.3 mmHg
- D100 mmHg
Show answer & explanationAnswer & explanation
Correct answer: C. 93.3 mmHg
MAP is calculated as diastolic pressure plus one-third of the pulse pressure: Pulse pressure = 120 − 80 = 40; one-third of 40 = 13.3; MAP = 80 + 13.3 = 93.3 mmHg. A MAP of at least 60 mmHg is generally needed to perfuse vital organs.
Why the other options are wrong
- A. 80 mmHg is simply the diastolic pressure, not the MAP.
- B. 120 mmHg is simply the systolic pressure, not the MAP.
- D. 100 mmHg would result from averaging systolic and diastolic incorrectly.
Mean Arterial Pressure (MAP)
The average pressure in a patient's arteries during one cardiac cycle, reflecting perfusion of vital organs.
- Formula: MAP = DBP + 1/3(SBP − DBP)
- Normal MAP range: 70–100 mmHg
- A MAP below 60 mmHg risks inadequate organ perfusion
Memory trick: 'Diastolic plus a third of the difference.'