From the Guidelines
A mean arterial pressure (MAP) of greater than 65 mmHg is generally recommended as the target for most critically ill patients requiring vasopressor support. This threshold has been established as the minimum pressure needed to maintain adequate organ perfusion, particularly to vital organs such as the brain, heart, and kidneys. When managing hypotensive patients, initial resuscitation should focus on adequate fluid administration before starting vasopressors like norepinephrine (typically first-line, starting at 0.05-0.1 mcg/kg/min, titrated to effect) 1. For patients who remain hypotensive despite adequate fluid resuscitation, vasopressors should be initiated promptly to maintain MAP ≥65 mmHg rather than continuing excessive fluid administration. This approach helps balance the risks of tissue hypoperfusion against the potential adverse effects of higher blood pressure targets, which include increased cardiac workload and arrhythmias. However, individualization is important - certain patients with chronic hypertension or specific conditions like traumatic brain injury may benefit from higher MAP targets (70-80 mmHg), while lower targets might be acceptable in younger patients without cardiovascular disease.
Some key points to consider:
- Norepinephrine is recommended as the first-line vasopressor agent to maintain adequate organ perfusion pressure in patients with septic shock 1.
- The optimal approach is to use an individualized MAP target based on frequent assessment of end-organ perfusion 1.
- Higher MAP targets may be necessary in patients with elevated venous or compartment pressures 1.
- Lower MAP targets may be acceptable in certain patients, such as those without cardiovascular disease or with specific conditions like traumatic brain injury 1.
Overall, the goal is to balance the risks and benefits of different MAP targets and to individualize treatment based on the patient's specific condition and response to therapy. The most recent and highest quality study, published in 2024, supports a MAP target of ≥65 mmHg in most critically ill patients requiring vasopressor support 1.
From the Research
Study Overview
- The study in question is about the effects of a Mean Arterial Pressure (MAP) of >65 mm Hg in critically ill patients.
- According to the study 2, a higher MAP goal of > 70 mm Hg 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 mm Hg.
Key Findings
- The study 2 found that both standard/low MAP goal and high MAP goal were associated with similar risk for mortality, duration of mechanical ventilation, and ICU length of stay.
- Subgroup analysis in cardiac arrest patients showed decreased ICU stay in patients with higher MAP goal compared to the standard MAP goal group without any difference in mortality or duration of mechanical ventilation 2.
- Another study 3 recommends norepinephrine as the first-choice vasopressor to maintain a mean arterial pressure ≥65 mm Hg in septic shock-induced hypotension in volume replete animals.
Vasopressor Therapy
- The use of vasopressors, such as norepinephrine, is common in the treatment of septic shock and vasodilatory shock 4.
- A study 5 found that arginine vasopressin (AVP) therapy was associated with stabilization or decrease of norepinephrine infusion rate in septic shock patients.
- Another study 6 compared vasopressin-receptor agonists with norepinephrine for hypotension among those undergoing surgery with general anesthesia, and found no significant difference in all-cause mortality.