The effects of low-dose dopamine infusions on haemodynamic and renal parameters in patients with septic shock requiring treatment with noradrenaline

Objective:To investigate whether low-dose dopamine (LDD) has a significant effect on systemic haemodynamic variables and renal function when used in conjunction with high-dose noradrenaline in optimally volume-resuscitated patients with septic shock. Design: A prospective clinical study in which each patient acted as his/her own control, Setting: Teaching hospital Intensive Care Unit. Patients: Twenty-one patients with septic shock treated with high-dose noradrenaline were studied, 17 patients completed the study Interventions: Fluid loading to an optimal left ventricular stroke work index (LVSWI) whilst on more noradrenaline than 10 mcg/min and dopamine of 2.5 mcg/kg per min. Three study periods each of 2 h with LDD present, withdrawn and restarted. During each period a complete haemodynamic profile and measurement of urine flow rate, creatinine clearance and sodium excretion was performed. Measurement and results: Removing and restarting LDD caused marked changes in cardiac index (CT, 17% fall, p < 0.01: 23 % rise, p < 0.01), stroke volume (SV, 11% fall, p < 0.05: 14 % rise, p < 0.05) and systolic blood pressure (SBP, 11% fall, p < 0.05. 14% rise, p < 0.05), Urine volume fell by 40 % (p < 0.05) when dopamine was withdrawn. Significant reductions in sodium excretion (p < 0.05) and fractional sodium excretion (p < 0.05) also occurred on stopping LLD, Changes in creatinine clearance were not statistically significant. Conclusion: Low-dose dopamine causes significant increases in SEP SV. cardiac output and urine flow during treatment with noradrenaline.