title: Early and sustained systemic and renal hemodynamic effects of intravenous radiocontrast.
abstract: OBJECTIVE
  To measure the extended renal hemodynamic changes induced by intravenous radiocontrast.
  
  
  METHODS
  Cross-ewes were studied in a randomized cross-over study. Intravenous saline or radiocontrast were administered, and continuous measurement of cardiac output and renal blood flow (RBF) was performed with flow probes.
  
  
  RESULTS
  Radiocontrast induced early but transient increases in cardiac output with vasodilatation, followed by return to baseline values within 2 h. There was an initial decline in RBF (-5.2 +/- 4.5 vs. 2.1 +/- 5.3%; p < 0.0001) and decreased renal vascular conductance (-4.0 +/- 7.2 vs. 3.3 +/- 7.1%, p < 0.0001; vasoconstriction). This renal vasoconstriction resolved within 2 h and was followed by sustained (72 h) renal vasodilatation with higher RBF (270 +/- 13 vs. 236 +/- 11 ml/min; p < 0.0001).
  
  
  CONCLUSIONS
  Radiocontrast induces short renal vasoconstriction followed by sustained vasodilatation and increased RBF. Short-term studies are not representative of the overall sustained renal hemodynamic effects of radiocontrast.
authors.affiliation: Howard Florey Institute, University of Melbourne, Parkville, Vic., Australia.
authors.forename: Takao
authors.initials: T
authors.lastname: Saotome
authors.forename: Christoph
authors.initials: C
authors.lastname: Langenberg
authors.forename: Li
authors.initials: L
authors.lastname: Wan
authors.forename: Rohit
authors.initials: R
authors.lastname: Ramchandra
authors.forename: Clive N
authors.initials: CN
authors.lastname: May
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Bellomo
authors.forename: Michael
authors.initials: M
authors.lastname: Bailey
authors.forename: Sean M
authors.initials: SM
authors.lastname: Bagshaw
mesh_terms: D000818:Animals; D002302:Cardiac Output; D003287:Contrast Media / Q000008:administration & dosage / Q000494:pharmacology*; D018592:Cross-Over Studies; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D007472:Iohexol / Q000008:administration & dosage / Q000494:pharmacology; D007668:Kidney / Q000098:blood supply*; D012039:Regional Blood Flow; D012756:Sheep; D014664:Vasodilation
chemical_list: D003287:Contrast Media; D007472:Iohexol