MAP
Formal Definition
Mean arterial pressure: the average arterial pressure throughout one cardiac cycle, calculated as diastolic pressure + one-third of pulse pressure (or approximately [systolic + 2×diastolic] / 3), representing the mean perfusion pressure driving blood to organs.
How It's Used on the Ward
"MAP is 58" or "MAP not maintaining" — a more physiologically meaningful target than systolic BP alone for assessing organ perfusion in critically ill patients.
Example
""Patient on two vasopressors: MAP hovering at 56–60. Goal MAP ≥65 for septic shock per Surviving Sepsis guidelines. Uptitrating norepinephrine — if still not there in 20 minutes, adding vasopressin.""
Clinical Context
MAP ≥65 mmHg is the resuscitation target in septic shock — below this, organ perfusion (kidneys, gut, brain) is at risk. A BP of 88/60 looks alarming by systolic; MAP is (88+120)/3 = 69 — actually adequate. MAP matters more than systolic alone for perfusion pressure in shock. ICU monitors display MAP continuously; on the floor it must be calculated from the cuff reading.