PURPOSE: We recently demonstrated that, compared to norepinephrine, dopamine was associated with a non significant increase in 28 day mortality (odds ratio 1.17 [0.97-1.42]) and also more arrhythmias (De Backer et al NEJM 362:779-789;2010). However, the study had very few exclusion criteria , so that some comorbidities. may have diluted the impact of the vasoactive agents. We conducted a per-protocol analysis limited to patients without major comorbidities.
METHODS: In a prospective, randomized study (NCT00314704), 858 patients received dopamine and 821 norepinephrine, according to a protocol described in detail elsewhere (De Backer et al NEJM 362:779-789;2010). In a univariate analysis, we first determined which factors were associated with an increased risk of death at day-28. After discarding patients with these severe comorbidities, we evaluated the odds ratios of 28-day survival and incidence of arrhythmias. Chi square and T-test were used to compare the effects of both agents and a p value <0.05 was considered as significant.
RESULTS: Advanced cancer, liver cirrhosis with Child Pugh score 3 and prior cardiac arrest were associated with increased risk of death. After discarding these patients, 1303 patients were kept for analysis, 662 in dopamine and 641 in norepinephrine group. The odds ratio for 28-day mortality associated with dopamine were 1.16 [0.93-1.44], p=0.21. The incidence of arrhythmias was 25.9% in dopamine and 22.5% in norepinephrine group (p<0.001).
CONCLUSION: Inclusion of patients with severe comorbidities did not influence the results of the trial. Dopamine remains associated with a non significant increased risk of death at day 28 and with a significant increased incidence of cardiac arrhythmias.
CLINICAL IMPLICATIONS: Norepinephrine should be preferred over dopamine as the first agent for the treatment of shock.
DISCLOSURE: Daniel De Backer, No Financial Disclosure Information; No Product/Research Disclosure Information