Septic Shock: Does Adrenaline have a Role as a First-line Inotropic Agent?

Fifteen adult patients, admitted to Baragwanath Hospital ICU with septic shock after adequate fluid loading and on no other inotropic agents, were given adrenaline in incremental doses. Oxygen transport and haemodynamic variables were monitored with each dose increment until a systolic blood pressure of 120 mmHg was obtained. This was reached on an average dose of adrenaline of 0.16±0.02 μg/kg/min. Mean arterial blood pressure increased by 22±2 mmHg mainly due to an increase in cardiac index (1±0.2 l/min/m²) and systemic vascular resistance index (130±41 dyn.s.cm.^-5m^-2) with a small increase in heart rate of 8±3 beats per minute. Oxygen delivery was increased with no significant increase in oxygen consumption and lactate levels increased. Adrenaline is therefore an effective initial inotropic agent. Patients may respond to lower doses than when used concurrently with other inotropic agents but there was still a significant dose variation in response. We cannot, however, exclude a deleterious effect on oxygen utilization.