Assessment of renal flow and flow reserve in humans.
OBJECTIVE
The purpose of this work was to establish the normal range of maximal renal hyperemic response in humans and to identify the ideal renal vasodilatory stimuli.


BACKGROUND
Stenotic renovascular atherosclerosis is increasingly treated by percutaneous transluminal renal intervention but with an unpredictable outcome. This may be due to hemodynamically non-significant stenosis or the presence of irreversible damage to the glomerular circulation. We propose that the renovascular hyperemic response may help identify appropriate patients.


METHODS
In 28 normotensive patients, quantitative angiographic measurements of the renal artery were obtained, and renal artery pressure and flow velocity were continuously recorded after various hyperemic agents.


RESULTS
In a first group of 11 patients, a significant increase in renal artery average peak velocity (APV) was observed after intrarenal (IR) bolus injection of 600 microg isosorbide dinitrate (41 +/- 19%), 30 mg papaverine (50 +/- 34%), 50 microg dopamine (94 +/- 54%), 0.8 microg x kg(-1) fenoldopam (80 +/- 25%), and during IR infusion of 1 microg x kg(-1) x min(-1) fenoldopam (86 +/- 28%). A second group of 17 patients received intravenous infusion of dopamine (3, 5, 10, 20, 30, and 40 microg x kg(-1) x min(-1)). The 3 and 5 microg x kg(-1) x min(-1) of dopamine modestly reduced renal resistance index (RI) (-13 +/- 15% and -25 +/- 20%, respectively). At higher dosages, no further decline in RI was observed. No significant change in vessel diameter was observed before and after the administration of the pharmacological stimuli suggesting that changes in APV corresponded with changes in absolute renal blood flow.


CONCLUSIONS
The normal renal flow reserve averages approximately 2 in humans with normal renal function. An IR bolus injection of 50 microg x kg(-1) of dopamine is the most convenient means to elicit maximal renal hyperemia.
Manoharan
Ganesh
G
Cardiovascular Centre Aalst, OLV-Clinic, Aalst, Belgium.
Pijls
Nico H J
NH
Lameire
Norbert
N
Verhamme
Katia
K
Heyndrickx
Guy R
GR
Barbato
Emanuele
E
Wijns
William
W
Madaric
Juraj
J
Tielbeele
Xanden
X
Bartunek
Jozef
J
De Bruyne
Bernard
B
D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D004298:Dopamine / Q000494:pharmacology; D005260:Female; D018818:Fenoldopam / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006940:Hyperemia; D007548:Isosorbide Dinitrate / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D010208:Papaverine / Q000494:pharmacology; D012079:Renal Circulation / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D010208:Papaverine; D007548:Isosorbide Dinitrate; D018818:Fenoldopam; D004298:Dopamine