BOX RCT – What’s the Right MAP Target for OHCA Patients?

October 12, 2022

Written by Clay Smith

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There was no difference in death or discharge with profound disability among comatose patients with out of hospital cardiac arrest (OHCA) randomized to a mean arterial pressure (MAP) goal of 63 or 77 mm Hg.

Why does this matter?
A MAP goal of 65 mm Hg is a reasonable target. But in OHCA, might a higher goal optimize cerebral perfusion? Small RCTs have been inconclusive. What would a larger study show?

A MAP to nowhere
789 patients with OHCA who remained comatose were randomized to a MAP goal of 63 or 77 mm Hg. This was a multifactorial trial, and patients were also randomized to either high or low PaO2 goal, which we will cover tomorrow. All patients had strict temperature control at 36°C. There was no difference in the composite outcome of death or discharge with profound residual disability (CPC score 3-4): 34% in the high MAP group and 32% in the low MAP group, HR 1.08 (95%CI 0.84 to 1.37). There was also no difference in secondary outcomes. Good neuroprotective care principles still apply: elevate the head of bed, avoid constricting ties or neck collars, avoid oxygen and CO2 extremes, avoid seizures, maintain strict normothermia, avoid hypoxia, and avoid hypotension. But pushing for high MAP goals is unhelpful in these patients.

Source
Blood-Pressure Targets in Comatose Survivors of Cardiac Arrest. N Engl J Med. 2022 Aug 27. doi: 10.1056/NEJMoa2208687. Online ahead of print.