Local intra-renal fenoldopam infusion causes greater increases in renal artery flow velocity than systemic intravenous fenoldopam infusion: a pilot study.

Abstract

Typical intravenous fenoldopam doses result in only minimal increases in renal blood flow and glomerular filtration, while higher doses are associated with systemic hypotension. We hypothesized that local infusion of fenoldopam into the renal arteries would enhance renal perfusion with reduction of arterial hypotension. Of 20 patients with renal impairment undergoing coronary intervention, 10 received infusion of fenoldopam into the left renal artery (IR). Doses were increased progressively (0.1,0.2,0.4 mcg/kg/min) at 5 min intervals, separated by a 10 min "wash out" period without drug application. Average and maximum peak renal blood flow velocities (APV and MPV) were measured using a flow-wire. A comparison group of 10 patients received renal flow measurements during IV fenoldopam application using the same escalating dose protocol without a drug-free period.The average peak flow velocity increased from 29.9+/-10.7 cm/s in the IR group and 25.9+/-7.7 cm/s in the IV group at baseline (p=ns) to 50.0+/-13.1 cm/s (IR) versus 31.0+/-11.9 cm/s (IV) at the maximum dose level (p=0.011). There was a trend towards attenuated reduction of the systemic pressure in the IR group compared to the IV group. In patients with renal insufficiency, local renal infusion of fenoldopam resulted in an approximately 50% increase in renal artery velocities without substantial blood pressure reduction compared to IV fenoldopam.