Early and Sustained Systemic and Renal Hemodynamic Effects of Intravenous Radiocontrast

Abstract

Background and Aims: 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.