Renal effects of dopamine in vascular surgical patients.

Low-dose dopamine (DA) is often used in surgical patients to induce diuresis when appropriate volume replacement is unsuccessful. Despite wide application, there are little objective data supporting any beneficial effects on renal hemodynamics in this patient population. To better define the response to dopamine in the clinical setting, we studied the renal effects of low-dose DA in 13 patients having vascular surgery. Glomerular filtration rate (GFR) and renal blood flow (RBF) were measured by inulin and p-aminohippurate clearance, respectively. Group I (n = 8) included patients in stable condition after operation who were administered intravenous DA, 0.5 micrograms/kg/min, for 2 hours. RBF significantly increased from 579 +/- 85 to 726 +/- 114 ml/min/1.73 m2 (p less than 0.05). Increases were also observed in GFR (95.0 +/- 10.9 to 107 +/- 15.7 ml/min/1.73 m2), sodium excretion (164 +/- 35 to 239 +/- 53 mu Eq/min), and osmolar excretion (709 +/- 78 to 866 +/- 93 mu Osm/min). There were no changes in urine output (2.17 +/- 0.36 to 2.49 +/- 0.43 ml/min). Group II (n = 5) consisted of patients having abdominal aortic surgery who were treated with DA, 2.0 micrograms/kg/min, before and after surgery. Increases in RBF were seen in both the preoperative period (414 +/- 59 to 659 +/- 96 ml/min/1.73 m2, p less than 0.01) and postoperative period (439 +/- 60 to 623 +/- 94 ml/min/1.73 m2, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)