COMMENTARY

Dopamine or Norepinephrine for Shock?

Gregory Martin, MD, MSc

Disclosures

June 28, 2010

Comparison of Dopamine and Norepinephrine in the Treatment of Shock

De Backer D, Biston P, Devriendt J, et al.
N Engl J Med. 2010;362:779-789

Study Summary

In the 1990s, dopamine was often the vasopressor of first choice for patients in shock, particularly septic shock.[1] As evidence that questioned the effectiveness and safety of dopamine emerged, norepinephrine became the drug of first choice in septic shock -- most firmly after the publication of the Surviving Sepsis Campaign guidelines.[2] In a large pragmatic trial, De Backer and colleagues sought to determine whether one agent is truly superior to the other by randomly assigning patients with shock to receive 1 of these 2 common drugs. Treatment with both drugs was started, and doses were titrated to maintain mean arterial pressure greater than 70 mm Hg; additional agents were given if doses reached maximum limits (20 µg/kg/min for dopamine and 0.19 µg/kg/min for norepinephrine). No difference was noted in the rate of death at 28 days (52.5% for dopamine; 48.5% for norepinephrine; P = .10), and patients who received dopamine had twice as many arrhythmias as those who received norepinephrine (24.1% vs 12.4%). In a subgroup analysis, dopamine was associated with an increased rate of 28-day mortality among the 280 patients with cardiogenic shock, but not among patients with septic or hypovolemic shock.

The investigators concluded that although no significant differences in mortality were evident between these 2 vasopressor treatments, norepinephrine should be the drug of first choice because dopamine was associated with more adverse events.

Viewpoint

This study addresses a common clinical question and an ongoing debate in the field of critical care medicine: What is the optimal vasopressor for patients with shock? This study answers that question reasonably well, with an overall mortality P value of .10 and a log-rank P value of .07 favoring norepinephrine. Although this value did not reach the traditional .05 threshold for statistical significance, it strongly suggests the superiority of norepinephrine over dopamine. This is particularly true for patients with septic shock, who accounted for 62% of the study population. In that group, norepinephrine seems to be the drug of first choice for support of systemic arterial blood pressure. For patients with cardiogenic shock, dopamine seems to result in more arrhythmias than norepinephrine; therefore, norepinephrine should probably be the drug of first choice for cardiogenic shock as well. However, it would be unusual to administer norepinephrine alone in cardiogenic shock, because patients could benefit from a purer or more titratable inotropic support separate from the alpha-adrenergic vasoconstrictor effect of norepinephrine. For patients with cardiogenic shock, further study is necessary to determine the optimal vasopressor/inotrope combination or other appropriate treatment regimens.

Abstract

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