The effects of fenoldopam on renal blood flow and tubular function during aortic cross-clamping in anaesthetized dogs

Abstract

Postoperative renal impairment is a recognized complication of infrarenal aortic cross-clamping. Fenoldopam, a selective dopamine agonist, may increase renal blood flow and decrease tubular oxygen consumption. The objective of this study was to quantify the effects of fenoldopam (0.1 microg kg-1 min-1) on renal blood flow and renal tubular function in anaesthetized dogs that have undergone aortic cross clamping. Eight labrador dogs were selected to receive either saline or fenoldopam (0.1 microg kg-1 min-1) intravenously. Arterial pressure, heart rate, renal blood flow, urinary output, fractional excretion of sodium, creatinine clearance and lithium clearance were measured (a) prior to infusions of saline or fenoldopam (b) 1 h after commencing the infusion (c) during a 90-min period of infrarenal aortic cross-clamping with concurrent infusion of fenoldopam or saline and (d) for 1 h after simultaneous aortic declamping and discontinuation of the infusions. There was no haemodynamic instability upon commencing the infusion of fenoldopam (0.1 microg kg-1 min-1). Creatinine clearance (2.03 +/- 0.5-2.45 +/- 0.3 mL min-1 kg-1 (mean +/- SD)), urine output (0.23 +/- 0.16-0.35 +/- 0.23 mL min-1 (mean +/- SD)), and fractional excretion of sodium (0.7 +/- 0.52-1.3 +/- 0.73% (mean +/- SD)) increased (P < 0.05), following commencement of the fenoldopam infusion. Fractional excretion of sodium (1.2 +/- 0.7% (mean +/- SD)) and urine output (0. 36 +/- 0.21 mL min-1 (mean +/- SD)) were maintained during the aortic cross-clamp period (P < 0.05). Renal blood flow increased when the fenoldopam infusion was commenced (145 +/- 43.3-161 +/- 39. 2 mL min-1 (mean +/- SD)) and remained greater than baseline during the aortic cross-clamping period (152 +/- 44 mL min-1 (mean +/- SD)), although these increases did not reach statistical significance. The most striking abnormalities observed by electron microscopy were marked disruption of the microvillus brush border in proximal tubules, vacuolation and separation of epithelial cells on basolateral infolds. The changes were similar in the two groups. In conclusion fenoldopam (0.1 microg kg-1 min-1) may have renoprotective effects which persist during infrarenal aortic cross clamping.

Effects of Fenoldopam Mesylate on Systemic Hemodynamics and Indices of Renal Function in Normotensive Neonatal Foals

“…In anesthetized dog, an increase in creatinine clearance was seen with fenoldopam at 0.1 mg/kg/min, 23 whereas in the normotensive human, no increase in creatinine clearance was seen at any dose of fenoldopam. 4 We did not find an increase in creatinine clearance with low-dose fenoldopam compared with saline.…”

“…This is in agreement with data from other species. 3,4,6,10,23 These data suggest that the neonatal foal is capable of a normal, mature systemic response to dopaminergic stimulation, but that the effects of highdose fenoldopam on the hemodynamics of the equine neonate may be more profound than those seen in other species.…”

Protective Effect of Remote Ischemic Preconditioning in Renal Ischemia/Reperfusion Injury, in a Model of Thoracoabdominal Aorta Approach

“…Several methods of protection from renal IR injury during TAAA open repair have been used such as distal aortic perfusion with selective renal perfusion [5], local hypothermia [4], and retrograde renal perfusion via the left renal vein either with cold blood or with Ringer's lactate solution. Various pharmacologic agents such as dopamine and prostaglandin inhibitors, dopaminergic agonists [6], or free radical scavengers [7] have been proposed to be useful in the clinical setting of IR injury. However, none of the previously described methods has been proven to be undoubtedly effective in protection from renal IR injury during TAAA open repair.…”

Nieren-Prophylaxe bei thorakaler Aortenchirurgie

“…Bleibt Fenoldopam, ein selektiver Dopamin-1-Agonist, dem besonders eine Förderung der kortikalen, renalen Durchblutung nachgewiesen wurde [16,17,26]. Auch hier gibt es zum jetzigen Zeitpunkt unterschiedliche Ergebnisse, vor allem von koronarchirurgischen Patienten mit oder ohne präope-rative Nierenfunktionseinschränkung [15,25,26].…”