Summary

Background and objective: Our hypothesis was that fenoldopam, a selective DA1 agonist, would protect against rhabdomyolysis-induced renal injury.

Methods: We studied the effects of intravenous fenoldopam (0.1–1.0 μg kg−1 min−1) or saline on renal blood flow and function in 10 anaesthetized Labrador dogs in whom rhabdomyolysis and myoglobinuric acute renal failure had been induced by administration of glycerol 50% (10 mL kg−1) intramuscularly. Haemodynamic measurements including renal blood flow and derived parameters of renal function including creatinine clearance were recorded before and for the 30 min following glycerol injection, and during the 3 h following commencement of each infusion. Serum malondialdehyde concentrations were measured before and 15 min after glycerol intramuscularly, and 30 and 150 min after commencement of the infusion.

Results: In the fenoldopam group, creatinine clearance was less than placebo at 1 and 2 h after commencing the infusion (12.7 ± 11.5 versus 31.3 ± 9.9 mL min−1, P = 0.04; 8.5 ± 5.3 versus 20.1 ± 7.4 mL min−1, P = 0.03). A 140-fold increase in serum malondialdehyde concentration occurred in one dog (fenoldopam group).

Conclusion: Fenoldopam increased the severity of the renal injury in this canine model of myoglobinuric acute renal failure.