Defending a mean arterial pressure in the intensive care unit: Are we there yet?

Excerpt

I read with great interest, the work of Jean-Louis Vincent and colleagues ‘Mean Arterial Pressure and Mortality in Patients with Distributive Shock: A Retrospective Analysis of the MIMIC-III Database’ [1]. I congratulate the authors on this work that highlights our current standards of care when it comes to protecting our critically ill patients against hypotension, as defined by a threshold mean arterial pressure (MAP). The surviving sepsis campaign guidelines recommend that vasopressors be titrated to a MAP of at least 65 mmHg while resuscitating septic shock [2]. Does this mean that a MAP of 65 mmHg ‘protects’ the critically ill patient from organ system injury? Or is this MAP of 65 mmHg the ‘one size fits all’ for all our patients? The only landmark-randomized control trial in this space has been performed by Asfar and colleagues. They randomized patients with septic shock to a low MAP target (65–70 mmHg) or a high MAP target (80–85 mmHg). The authors reported that average MAP values in the low MAP target arm were above 70 mmHg and in the high MAP target arm were closer to 85 mmHg. However, the allocation of patients to either MAP group did not influence 28-day or 90-day mortality [3]. Several new questions have been asked recently, and within the limitations of retrospective data, these thresholds may be different and higher than a MAP of 65 mmHg as the only perceived ‘magic number’ [4]. …