MAP Calculator

Calculate Mean Arterial Pressure to assess perfusion pressure and guide vasopressor therapy

Indication

Calculate Mean Arterial Pressure to assess perfusion pressure and guide vasopressor therapy

Criteria

id: sbp; label: Systolic Blood Pressure (mmHg); type: number; placeholder: e.g. 120
id: dbp; label: Diastolic Blood Pressure (mmHg); type: number; placeholder: e.g. 80

Interpretation

function(map) { if (map < 60) return { risk: 'Critical \u2014 Severe Hypoperfusion', tier: 'high', action: 'MAP <60 mmHg is incompatible with adequate organ perfusion. Immediate intervention required \u2014 IV fluids, vasopressors, identify and treat cause. Risk of AKI, myocardial ischemia, and mesenteric ischemia.', color: 'red', }; if (map < 65) return { risk: 'Low \u2014 Inadequate Perfusion', tier: 'high', action: 'MAP <65 mmHg is below the minimum target for most critically ill patients. Start or uptitrate vasopressors. Reassess volume status.', color: 'red', }; if (map <= 70) return { risk: 'Borderline', tier: 'medium', action: 'MAP 65\u201370 mmHg is at the minimum acceptable range. Monitor closely. Target \u226565 in septic shock. Higher targets (\u226580) needed in TBI, chronic hypertension, and post-cardiac arrest.', color: 'yellow', }; if (map <= 100) return { risk: 'Normal', tier: 'low', action: 'MAP within normal range (70\u2013100 mmHg). Adequate for organ perfusion in most patients.', color: 'green', }; if (map <= 110) return { risk: 'Elevated', tier: 'medium', action: 'MAP >100 mmHg may indicate hypertension. Consider antihypertensive therapy if sustained, especially in post-op patients or those with end-organ damage.', color: 'yellow', }; return { risk: 'Severely Elevated', tier: 'high', action: 'MAP >110 mmHg indicates severe hypertension. Assess for hypertensive emergency \u2014 end-organ damage (neurological symptoms, chest pain, acute kidney injury). Consider IV antihypertensive therapy.', color: 'red', }; }

Clinical pearls

MAP = (SBP + 2×DBP) / 3 — diastole is weighted double because the heart spends approximately twice as long in diastole as systole
MAP ≥65 mmHg is the standard resuscitation target in septic shock — higher targets (≥80) are needed in patients with chronic hypertension or TBI
A normal MAP does not rule out inadequate perfusion — check lactate to confirm tissue oxygen delivery is adequate
Pulse pressure (SBP − DBP) widens in septic shock (vasodilation) and narrows in cardiogenic or obstructive shock
Norepinephrine increases MAP primarily by increasing SVR — monitor for reflex bradycardia and end-organ ischemia at high doses

Source and review

Pinsky MR. Functional Hemodynamic Monitoring. Intensive Care Med 2002; Surviving Sepsis Campaign 2021. Last reviewed: 2024-11-01