Plasma dopamine concentration and effects of low dopamine doses on urinary output after major vascular surgery

To evaluate plasma dopamine concentration and the effects of low doses infusion on urinary output after abdominal vascular surgery in patients with renal function impairment we performed a prospective clinical study. Twenty hemodynamically stable patients (mean age 66.6 years), with serum creatinine concentration < 2 mg %, who undergoing general anesthesia for major vascular surgery participated. A low dose of dopamine (3 μg/kg/min) was administrated to patients with postoperative protracted urinary output < 0.5 ml/kg/hr for at least eight hours. Plasmatic determinations were taken at T0 (no dopamine administration), when urinary output began to increase, or if not, after two hours (T1), at eight (T2) and 24 (T3) hours after the beginning of infusion. After 24 hours the dopamine infusion was stopped and the patient's plasmatic level was measured four hours later (T4). Dopamine plasma concentrations were measured using high-performance liquid chromatography. Plasma dopamine concentratio...