Radiocontrast-induced nephropathy in humans: role of renal vasoconstriction

Radiocontrast-induced nephropathy (RCIN) is a common cause of acute renal failure in hospitalized patients. Renal vasoconstriction figures prominently in the proposed pathogenesis of RCIN based on animal experiments. Prior human studies examining renal hemodynamic changes after contrast medium (CM) injection are inconclusive. No previous study of animals or humans has established a relationship between CM-associated renal hemodynamic changes and the subsequent development of RCIN. In the present study, we examined the renal hemodynamic effects of CM in patients at high risk of RCIN. In addition, we related those effects to the subsequent development of RCIN. Using renal vein thermodilution catheters, we measured renal blood flow (RBF) in 12 patients with chronic renal failure [serum creatinine (SCr) greater than or equal to 159 mumol/liter] during ionic CM injection for cardiac catheterization. We made measurements at the start of the procedure (t = 0), before the ventriculogram (t = 5), after the ventriculogram (t = 15), and after the coronary angiogram (t = 65). We measured SCr at t = 0 and again 24 and 48 hours later. Mean RBF for the group tended to increase after the ventriculogram, and increased significantly by t = 65 (P less than 0.005 vs. t = 0). When examined by individual patient, RBF fell below baseline in three patients (30%) at t = 15, but rose above baseline again by t = 65. Only one patient (8.3%) had a fall in RBF below baseline at t = 65. RCIN (defined as an increase in SCr greater than or equal to 25% above baseline) developed in six patients (50%) within 48 hours.(ABSTRACT TRUNCATED AT 250 WORDS)