Vasopressors

Which pressor to choose?

Preferred pressor / inotrope
Typical dose
Avoid / caution
Key physiology

Vasopressors & Inotropes

Drug Comparison

Drug Receptors / Mechanism Typical Dose Key Pearls
Norepinephrine α1 >>> β1 1–40 mcg/min First-line septic/distributive shock. Strong vasoconstriction with less tachyarrhythmia. Good MAP support. Relatively neutral PVR.
Epinephrine β1/β2 low dose, α1 higher dose 1–20 mcg/min Anaphylaxis, refractory shock, peri-arrest. Increases HR/CO. Raises lactate and glucose.
Vasopressin V1/V2 agonist 0.03 U/min fixed Septic shock adjunct. Effective in acidemia. Relatively neutral PVR, useful in RV failure/PE. High doses risk digital/mesenteric ischemia.
Phenylephrine Pure α1 40–180 mcg/min Raises SVR without β stimulation. Useful in AF w/ RVR, HOCM, anesthesia hypotension. Reflex bradycardia may lower CO. Avoid in RV failure.
Dopamine DA → β1 → α1 dose dependent 2–20 mcg/kg/min Arrhythmogenic. Inferior outcomes vs norepi. Rarely used now.
Dobutamine β1 > β2 2.5–5 mcg/kg/min Inodilator. Improves CO in cardiogenic shock/RV failure. Can worsen hypotension/tachyarrhythmias.
Milrinone PDE-3 inhibitor 0.125–0.75 mcg/kg/min Inotropy + vasodilation independent of β receptors. Good for RV failure/pulm HTN/β-blocker patients. Long half-life, renal clearance, hypotension risk.
Isoproterenol Pure β agonist 1–10 mcg/min Severe bradycardia, torsades, β-blocker overdose. Potent chronotrope/inotrope. Can cause major tachyarrhythmias/hypotension.

Quick Pressor Selection

Scenario Preferred Avoid / Caution Key Physiology
Septic shock Norepi ± vasopressin Dopamine Best mortality data.
Refractory septic shock Norepi + vaso ± epi Phenylephrine Add inotropy/catecholamine sparing.
Anaphylaxis Epinephrine Phenylephrine β2 bronchodilation + mast cell stabilization.
Cardiogenic shock + hypotension Norepi + dobutamine Dopamine MAP support + improved CO.
Cardiogenic shock normotensive Dobutamine or milrinone Excess vasoconstrictors Improve forward flow.
Massive PE / obstructive shock Norepi ± vaso, low-dose dobutamine or epi if low CO Phenylephrine, excess fluids Support RV perfusion while minimizing PVR.
RV failure / pulm HTN Milrinone, dobutamine, vasopressin Phenylephrine, high-dose norepi RV sensitive to ↑PVR.
RV infarct Norepi ± dobutamine Phenylephrine Maintain coronary perfusion + RV contractility.
HOCM / dynamic LVOTO Phenylephrine, vasopressin, cautious fluids Dobutamine, milrinone, epi, nitrates Need ↑afterload/preload and less inotropy.
Takotsubo w/ LVOTO Phenylephrine, vasopressin Inotropes Inotropes worsen obstruction.
Severe AS shock Norepi or phenylephrine Excess vasodilation Maintain coronary perfusion pressure.
Acute MR/AI shock Dobutamine ± afterload reduction Phenylephrine Forward flow improves with lower SVR.
AF w/ RVR + hypotension Phenylephrine or vasopressin Epi, dobutamine, isoproterenol Avoid worsening tachycardia.
Bradycardia / torsades Isoproterenol or epi Phenylephrine, vasopressin alone Need chronotropy.
Severe acidosis Vasopressin Catecholamines alone Catecholamine receptors less responsive.
Peri-arrest / crashing Epinephrine Milrinone Rapid α + β support.
Chronic β-blocker use Milrinone Dobutamine Bypasses β receptor.

Cardiology Pearls

  • Massive PE: RV failure is primary issue. Norepi usually first-line. Vasopressin is attractive because relatively PVR-neutral. Avoid phenylephrine.
  • HOCM/LVOTO: opposite of classic cardiogenic shock. Avoid inotropes and vasodilators. Increase preload and afterload.
  • RV failure hates hypoxia, hypercapnia, acidosis, high PEEP, and α-mediated pulmonary vasoconstriction.
  • “Wet and cold” cardiogenic shock is often norepi + dobutamine.
  • Pure vasoconstriction without inotropy can worsen low-output cardiogenic shock.
  • Milrinone is especially useful in RV failure, pulmonary HTN, and β-blocker patients.
  • Vasopressin often works better in profound acidemia than catecholamines.

References

  1. Evans, L., Rhodes, A., Alhazzani, W., Antonelli, M., Coopersmith, C. M., French, C., Machado, F. R., McIntyre, L., Ostermann, M., Prescott, H. C., Schorr, C., Simpson, S., Wiersinga, W. J., Alshamsi, F., Angus, D. C., Arabi, Y., Azevedo, L., Beale, R., Beilman, G., ... Levy, M. (2021). Surviving Sepsis Campaign: International guidelines for management of sepsis and septic shock 2021. Intensive Care Medicine, 47(11), 1181–1247. https://doi.org/10.1007/s00134-021-06506-y
  2. De Backer, D., Biston, P., Devriendt, J., Madl, C., Chochrad, D., Aldecoa, C., Brasseur, A., Defrance, P., Gottignies, P., Vincent, J. L., & SOAP II Investigators. (2010). Comparison of dopamine and norepinephrine in the treatment of shock. New England Journal of Medicine, 362(9), 779–789. https://doi.org/10.1056/NEJMoa0907118
  3. Russell, J. A., Walley, K. R., Singer, J., Gordon, A. C., Hébert, P. C., Cooper, D. J., Holmes, C. L., Mehta, S., Granton, J. T., Storms, M. M., Cook, D. J., Presneill, J. J., Ayers, D., & VASST Investigators. (2008). Vasopressin versus norepinephrine infusion in patients with septic shock. New England Journal of Medicine, 358(9), 877–887. https://doi.org/10.1056/NEJMoa067373
  4. Levy, B., Clere-Jehl, R., Legras, A., Morichau-Beauchant, T., Leone, M., Frederique, G., Quenot, J. P., Kimmoun, A., Cariou, A., Lassus, J., Harjola, V. P., Meziani, F., Louis, G., Rossignol, P., Duarte, K., Girerd, N., Mebazaa, A., & Epinephrine Versus Norepinephrine for Cardiogenic Shock After Acute Myocardial Infarction Investigators. (2018). Epinephrine versus norepinephrine for cardiogenic shock after acute myocardial infarction. Journal of the American College of Cardiology, 72(2), 173–182. https://doi.org/10.1016/j.jacc.2018.04.051
  5. Mathew, R., Di Santo, P., Jung, R. G., Marbach, J. A., Hutson, J., Simard, T., Ramirez, F. D., Harnett, D. T., Merdad, A., Almufleh, A., Weng, W., Abdel-Razek, O., Fernando, S. M., Le May, M. R., Wells, G. A., Hibbert, B., & Russo, J. J. (2021). Milrinone as compared with dobutamine in the treatment of cardiogenic shock. New England Journal of Medicine, 385(6), 516–525. https://doi.org/10.1056/NEJMoa2026845
  6. Ventetuolo, C. E., & Klinger, J. R. (2014). Management of acute right ventricular failure in the intensive care unit. Annals of the American Thoracic Society, 11(5), 811–822. https://doi.org/10.1513/AnnalsATS.201312-446FR
  7. Naidu, S. S., Baran, D. A., Jentzer, J. C., Hollenberg, S. M., van Diepen, S., Basir, M. B., Grines, C. L., Diercks, D. B., Hall, S., Kapur, N. K., Kent, W., Sinha, S. S., Thiele, H., Zweck, E., & Henry, T. D. (2022). SCAI SHOCK stage classification expert consensus update: A review and incorporation of validation studies. Journal of the American College of Cardiology, 79(9), 933–946. https://doi.org/10.1016/j.jacc.2022.01.018