What is the recommended Mean Arterial Pressure (MAP) range to maintain?

Mean Arterial Pressure Target in Critically Ill Patients

For most critically ill patients, maintain a MAP of ≥65 mmHg as the initial target, with specific adjustments to 70-85 mmHg for patients with chronic hypertension, spinal cord injury, or elevated compartment pressures. 1, 2

Standard MAP Target: 65 mmHg

• The Surviving Sepsis Campaign guidelines establish MAP ≥65 mmHg as the initial vasopressor target for septic shock patients 1
• This 65 mmHg threshold represents the critical point below which organ autoregulation fails and blood flow becomes linearly dependent on arterial pressure 2
• The 2024 AHA/ACC perioperative guidelines recommend maintaining intraoperative MAP ≥60-65 mmHg or SBP >90 mmHg, noting that harm thresholds appear around MAP <65 mmHg maintained for approximately 15 minutes 1
• In acute meningitis and meningococcal sepsis, a MAP ≥65 mmHg is recommended, though this may need individualization based on age and clinical presentation 1

Elevated MAP Targets for Specific Populations

Chronic Hypertension (Target: 70-85 mmHg)

• Patients with chronic hypertension require MAP targets of 70-85 mmHg due to rightward shift of their autoregulation curve 2, 3
• A study in septic shock patients with hypertension found that MAP 72-82 mmHg was necessary to prevent acute kidney injury in those with initial renal impairment 4
• Higher MAP targets (80-85 mmHg) in chronically hypertensive patients minimize renal injury but increase arrhythmia risk 3

Spinal Cord Injury (Target: ≥70 mmHg)

• French guidelines recommend maintaining MAP ≥70 mmHg during the first week after spinal cord injury to limit neurological deficit worsening 1
• This recommendation is based on correlation between MAP >70-75 mmHg and neurological improvement, with optimal spinal perfusion pressure >50 mmHg requiring MAP >70 mmHg 1
• Continuous arterial catheter monitoring is recommended as MAP falls below target 25% of the time 1

Elevated Compartment Pressures (Target: MAP = Desired Perfusion Pressure + Compartment Pressure)

• When venous or compartment pressures are elevated, increase MAP targets to compensate for reduced organ perfusion pressure 1, 2
• The 2024 POQI consensus recommends adding the estimated compartment pressure to the desired perfusion pressure (e.g., if targeting 65 mmHg perfusion with 15 mmHg intra-abdominal pressure, maintain MAP ≥80 mmHg) 1
• This is particularly critical in abdominal compartment syndrome, steep Trendelenburg positioning, or peritoneal insufflation 1, 2

Calculating True Perfusion Pressure

• MAP alone does not reflect actual organ perfusion pressure—calculate trans-organ perfusion pressure as MAP minus central venous pressure (CVP) 2
• Trans-kidney perfusion pressure (TKPP = MAP - CVP) should exceed 60 mmHg in heart failure and fluid-overloaded patients 2
• Elevated CVP from venous congestion critically reduces net perfusion pressure independent of cardiac output 2

Monitoring Beyond MAP

MAP is necessary but insufficient for assessing adequate perfusion—monitor these concurrent parameters: 2

• Urine output (goal >0.5 mL/kg/h) 2
• Lactate clearance 2
• Mental status 2
• Skin perfusion and capillary refill 2
• Creatinine trends 2

Evidence Limitations and Practical Application

• The POISE-3 trial randomized 7,490 patients to MAP ≥80 mmHg versus ≥60 mmHg strategies and found no benefit from higher targets, though interpretation is complicated by lack of detail on time spent in the harmful 55-70 mmHg range 1
• A 2022 meta-analysis of 6 RCTs (3,753 patients) found no mortality difference between standard (60-70 mmHg) and high (≥70 mmHg) MAP targets in general critically ill populations 5
• Despite equivocal trial evidence, observational data consistently shows harm below MAP 65 mmHg, making this the safest initial target 1, 2

Common Pitfalls to Avoid

• Do not assume MAP 65 mmHg is adequate for all patients—chronic hypertension, spinal cord injury, and elevated compartment pressures require higher targets 1, 2, 3
• Do not use MAP as the sole endpoint—blood pressure alone does not reflect cardiac output or tissue perfusion 2
• Do not ignore CVP when available—elevated venous pressure reduces actual perfusion pressure even with adequate MAP 2
• Do not target supranormal MAP (>85 mmHg) without specific indication—this increases vasopressor requirements and arrhythmia risk without proven benefit 2, 3

Practical Algorithm

1. Start with MAP ≥65 mmHg for all patients 1, 2
2. Increase target to 70-85 mmHg if: 1, 2, 3
   • Documented chronic hypertension
   • Spinal cord injury (first 7 days)
   • Elevated intra-abdominal pressure >12 mmHg
3. Calculate TKPP (MAP - CVP) and ensure >60 mmHg in heart failure or fluid overload 2
4. Titrate MAP up or down based on organ function markers (urine output, lactate, mental status) rather than fixed targets alone 2, 3
5. Use norepinephrine as first-line vasopressor to achieve MAP targets 1, 2