Contributor: Travis Barlock MD

Educational Pearls:

• Three categories of pressors: inopressors, pure vasoconstrictors, and inodilators

• Inopressors:

• Epinephrine - nonselective beta- and alpha-adrenergic agonism, leading to increased cardiac contractility, chronotropy (increased heart rate), and peripheral vasoconstriction. Dose 0.1mcg/kg/min.

• Levophed (norepinephrine) - more vasoconstriction peripherally than inotropy; useful in most cases of shock. Dose 0.1mcg/kg/min.

• Peripheral vasoconstrictors:

• Phenylephrine - pure alpha agonist; useful in atrial fibrillation because it avoids cardiac beta receptor activation and also in post-intubation hypotension to counteract the RSI medications. Start at 1mcg/kg/min and increase as needed.

• Vasopressin - No effect on cardiac contractility. Fixed dose of 0.4 units/min.

• Inodilators are useful in cardiogenic shock but often not started in the ED since patients mostly have undifferentiated shock

• Dobutamine - start at 2.5mcg/kg/min.

• Milrinone - 0.125mcg/kg/min.

References

1. Ellender TJ, Skinner JC. The Use of Vasopressors and Inotropes in the Emergency Medical Treatment of Shock. Emerg Med Clin North Am. 2008;26(3):759-786. doi:https://doi.org/10.1016/j.emc.2008.04.001

2. Hollenberg SM. Vasoactive drugs in circulatory shock. Am J Respir Crit Care Med. 2011;183(7):847-855. doi:10.1164/rccm.201006-0972CI

3. Lampard JG, Lang E. Vasopressors for hypotensive shock. Ann Emerg Med. 2013;61(3):351-352. doi:10.1016/j.annemergmed.2012.08.028

Summarized by Jorge Chalit, OMSII | Edited by Meg Joyce & Jorge Chalit, OMSII