Early and aggressive use of high-dose norepinephrine in the treatment of septic shock

Introduction

Hyperdynamic circulation of septic shock is characterized in the hyperdynamic phase by increased cardiac output and decreased peripheral vascular resistance, and consequently low pressure. The use of norepinephrine as a pure vasoconstrictor aims to increase vascular resistance and blood pressure. There is a subgroup of patients with septic shock that does not respond to usual or high doses of norepinephrine. Usually in these patients different therapeutic approaches are used. In this study, we try to evaluate the role of very high doses of norepinephrine (≥ 2 μg/kg/min) in the treatment of septic shock.

Patients and methods

In our department the therapeutic approach to septic shock includes the use of aggressive haemodynamic monitoring (pulmonary artery catheterization) and the use of norepinephrine and/or dobutamine combination along with fluid resuscitation. In this retrospective study we present 12 patients with septic shock that required very high doses of norepinephrine (≥ 2 μg/kg/min). All patients were catheterized with a Swan–Ganz catheter and received adequate fluid resuscitation (pulmonary wedge pressure ≥ 15 mmHg). Norepinephrine was used and titrated to maintain mean arterial pressure >70 mmHg. In nine of 12 patients dobutamine was added to achieve cariac index >3.5 l/min/m².

Results

Two patients never recovered from septic shock and died. Another six patients expired at a later time from multiple organ failure despite the fact that they improved from the shock and they were weaned off norepinephrine during their course. Finally, four patients survived to be discharged from the intensive care unit after a mean 25 days of intensive care unit stay. The APACHE II score did not differ between survivors and nonsurvivors (Table 1).

Table 1

Conclusion

The use of very high doses of norepinephrine in the treatment of septic shock under the guidance of aggressive haemodynamic monitoring may improve survival in this group of patients with very high mortality. We may need to reconsider labeling patients with norepinephrine-resistant septic shock if the usual doses are ineffective, and try high doses before switching to another regimen.