Metaraminol and Noradrenaline in Septic Shock: A Retrospective Comparison

Abstract IntroductionVasopressor use is an important facet of septic shock management, in order to maintain hemodynamic targets and end organ perfusion. Traditionally, Noradrenaline has been the ‘gold standard’ drug of choice for septic shock. Metaraminol is an alternative vasopressor that has been used for septic shock. However, there has been minimal research in comparing the two drugs in septic patients, particularly with regards to total time spent on infusion. ObjectivesTo compare total time spent on either Metaraminol or Noradrenaline infusion by septic shock patients, whilst adjusting for baseline severity of illness. Secondary outcomes included incidence of mechanical ventilation and new requirement of renal replacement therapy, and mortality. MethodsA retrospective medical records review was undertaken, looking at all septic shock patients admitted to ICU in 2019, who received either Metaraminol or Noradrenaline. Data extracted from eRIC (the ICU database) included total time spent on infusion, APACHE III scores, incidence of mechanical ventilation, incidence of renal replacement therapy, and mortality. ResultsOur review yielded 174 patients who were eligible for further statistical analysis (63 in Metaraminol group, and 111 in the Noradrenaline group). The mean duration of infusion in the Metaraminol group was 1655 minutes, and 2663 minutes in the Noradrenaline group. The mean APACHE III Scores were 62 in the Metaraminol group and 77 in the Noradrenaline group. A one-way ANCOVA test found that there was a statistically significant [F(1, 171)=4.511, p=0.035] reduction in time spent on Metaraminol infusion, compared with Noradrenaline, after adjusting for baseline severity of illness by way of APACHE III Score. ConclusionOur study found a statistically significant reduction in time spent on a Metaraminol infusion compared with Noradrenaline by septic shock patients, after controlling for severity of illness. However, due to its retrospective study design, we were unable to account for bias and confounders, such as antibiotic and fluid administration, or clinician preference for one drug over the other. Nevertheless, our study adds to the paucity of literature comparing Metaraminol to Noradrenaline, and paves the way for future randomized trials comparing the two drugs in septic shock.