From the Guidelines
A Mean Arterial Pressure (MAP) of 56 mmHg is significantly low and indicates inadequate organ perfusion, which can lead to tissue hypoxia and organ failure.
Key Points
- A MAP below 60-65 mmHg is considered hypotensive and can lead to pressure-dependent organ perfusion 1.
- The Surviving Sepsis Campaign recommends an initial MAP target of 65 mmHg for patients with septic shock 1.
- A MAP of 56 mmHg is below the recommended target and may require vasopressor support to improve microcirculatory flow and prevent organ dysfunction 1.
- The optimal MAP target may vary depending on individual patient factors, such as underlying medical conditions and response to treatment 1.
Clinical Implications
- A MAP of 56 mmHg is associated with an increased risk of postoperative myocardial injury, acute kidney injury, and mortality in patients undergoing noncardiac surgery 1.
- Prompt administration of intravenous fluids and vasopressor agents may be necessary to improve tissue perfusion and prevent organ failure 1.
- Clinical endpoints, such as mean arterial pressure, skin color and capillary refill, mental status, and urinary output, should be monitored to guide fluid resuscitation and vasopressor support 1.
From the Research
Significance of Mean Arterial Pressure (MAP) of 56 mmHg
- A MAP of 56 mmHg is considered low and may be associated with increased incidence of acute kidney injury (AKI) 2
- In patients with sepsis, targeting a lower MAP was associated with increased incidence of AKI, while targeting a higher MAP resulted in increased net positive fluid balance and vasopressor load during resuscitation 2
- A meta-analysis of randomized controlled trials found that a higher MAP goal of > 70 mmHg was associated with a similar risk of mortality, duration of mechanical ventilation, and ICU length of stay when compared with a standard MAP goal of 60 - 70 mmHg 3
- Another meta-analysis found that there was no significant difference in all-cause mortality between lower (60-70 mmHg) and higher (>70 mmHg) MAP target groups in patients with vasodilatory shock 4
- A study on patients with cardiogenic shock found that hospital mortality was inversely associated with mean MAP during the first 24 hours, and patients with a mean MAP < 65 mmHg were at higher risk of hospital mortality 5
Comparison with Other MAP Values
- A MAP of 56 mmHg is lower than the recommended target of 65 mmHg or more in critically ill medical patients 3
- A MAP of 56 mmHg is also lower than the optimal MAP target for patients with vasodilatory shock, which is > 70 mmHg 4
- However, a MAP of 56 mmHg is close to the lower end of the standard MAP goal of 60 - 70 mmHg 3
Clinical Implications
- A MAP of 56 mmHg may require closer monitoring and potential intervention to prevent organ dysfunction and improve outcomes 2, 3, 4, 5
- Clinicians should consider the individual patient's condition and adjust the MAP target accordingly, taking into account the potential risks and benefits of different MAP values 2, 3, 4, 5