Norepinephrine and metaraminol in septic shock: a comparison of the hemodynamic effects

To compare the effects of norepinephrine and metaraminol on hemodynamics in septic shock patients.

Open-label, controlled clinical trial in the general intensive care unit of a university-affiliated hospital.

Ten consecutive septic shock patients receiving norepinephrine to maintain the mean arterial pressure higher than 65 mmHg.

Patients were monitored with pulmonary artery catheter and indirect calorimetry. At the baseline hemodynamic variables were obtained during norepinephrine infusion. Subsequently norepinephrine was replaced by metaraminol infusion in a dose sufficient to keep mean arterial pressure constant. After 20 min of stable arterial pressure a new set of measurement was repeated.

Mean arterial pressure did not differ significantly with norepinephrine or metaraminol; there was no relationship between the norepinephrine and metaraminol doses. Replacement norepinephrine with metaraminol did not modify hemodynamic variables; in particular there were no changes in heart rate, stroke volume index, pulmonary artery occlusion pressure, or oxygen consumption index.

This study shows that metaraminol increases arterial pressure as does norepinephrine in septic shock patients. Despite similar effects of norepinephrine and metaraminol, there was no relationship between the dose of the two drugs.