Blood pressure help

[lizzie1991]

What must the systolic blood pressure be valued at for adequate mean arterial pressure if the diastolic pressure is 75? (resting conditions assumed)

at least 90? 95? 100? 105? 110? 115? 120?

Which of those (only one of them) is correct?

I'm confused.

[nurseprnRN, BSN, RN]

did they give you a formula for calculating mean arterial pressure and tell you what they think is "adequate"? if so, what it's asking you is to plug those numbers into the formula (using the 75 for the diastolic) and see which one is the answer.

at normal resting heart rates, map can be approximated by the following equation (thank you, wikipedia):

this says, "mean arterial pressure is approximately equal to diastolic plus 1/3 (systolic minus diastolic)"

for example, if systolic pressure is 120 mmhg and diastolic pressure is 80 mmhg, then the mean arterial pressure is approximately 93 mmhg using this calculation. at high heart rates, however, map is closer to the arithmetic average of systolic and diastolic pressure (therefore, almost 100 mmhg in this example) because of the change in shape of the arterial pressure pulse (it becomes narrower). a decent map is usually given as 60-110mmhg.