Predictors of dysrhythmias with norepinephrine use in septic shock

Norepinephrine (NE) is recommended first-line for treatment of septic shock, partly due to its intrinsically low effect on heart rate. While dysrhythmias secondary to NE are still reported, factors associated with development of this adverse effect have not been described. Our study sought to investigate factors associated with dysrhythmias in patients receiving NE for septic shock.

We conducted a retrospective cohort study of adults receiving NE for septic shock if NE was initiated as the first vasopressor and continued for at least 6 h. The primary objective was to determine the rate of dysrhythmias among this patient population. Secondary objectives included determining the effect of dysrhythmia development on patient outcomes and elucidating predictors for dysrhythmia development.

Of the 250 patients included, 34.4% (n = 86) developed a dysrhythmia. These patients had higher mortality (30.5% vs. 63.9%; p < 0.001) with decreased ICU-free days (2 vs. 4; p = 0.04) and ventilator-free days (7 vs. 4; p = 0.048). Duration of NE infusion and maximum NE dose were found to be independently associated with increased rates of dysrhythmia (p < 0.005).

Development of dysrhythmia is associated with increased mortality and is independently associated with longer duration of NE infusion and higher NE doses.