A listener, Dave Glaser, points out that one portion of the EGDT protocol doesn’t get spoken about very often: the use of vasodilators for MAP optimization.
In the original trial, patients in the EGDT arm of the study got a vasodilator if their MAPs were >90. The original trial publication makes no mention of which vasodilator and how many patients received it. If you want that information, you need to go to the Otero et. al publication (Chest 2006;130;1579-1595), which expanded on the original trial with additional information. Here is the relevant excerpt:
After adequate volume and hemoglobin targets were met, we surprisingly found that 9% of EGDT patients met the protocol criteria for afterload reduction for a mean arterial pressure (MAP) of > 90 mm Hg by utilizing nitroglycerin therapy. Nitroglycerin was chosen because of its effects on preload, afterload, and coronary vasodilation. All of these patients had a history of hypertension and congestive heart failure. The median baseline Scvo2 was 46% in this subset of patients. Although the use of nitroglycerin was unexpected on study initiation, therapy with afterload reduction is not without precedent in treating sepsis patients.
Cerra et al (J Surg Res 1978;25:180–183) provided vasodilator therapy to sepsis patients with low cardiac output and observed physiologic improvement.
Spronk et al (Lancet. 2002 Nov 2;360(9343):1395-6) found that nitroglycerin may improve microcirculatory flow in normotensive or even hypotensive patients with septic shock.
It is becoming increasingly evident that disordered microcirculatory flow is associated with systemic inflammation, acute organ dysfunction, and increased mortality. Using new technologies to directly image microcirculatory blood flow may help to define the role of microcirculatory dysfunction in oxygen transport and circulatory support.
I can’t remember the last time I saw a patient who would be eligible for this therapy b/c of high MAP. We have given nitroglycerin occasionally for a patient that is not clearing their lactate with a high ScvO2.
For anyone who really wants to dive deep on this issue, there is a free supplement in Critical Care.