Nonionic iodinated contrast media: potential renal damage assessed with enzymuria

The potential of digital subtraction angiography (DSA) to enable study of the physiology of renal transplantation after a single intravenous injection of nonionic iodinated contrast material stimulated this investigation into the possible nephrotoxicity of the contrast material used. Levels of urinary enzyme activity, used as markers of renal damage, were measured before, immediately after, and up to 72 hours after intravenous injection of nonionic iodinated contrast material in two groups of patients undergoing DSA. Twenty-six patients had undergone renal transplantation and 10 control patients had normal renal function. Both groups showed a transient rise in the level of urinary enzyme activity that peaked within 24 hours and returned to levels obtained before DSA within 72 hours. In the transplantation group, the baseline levels of enzymes were higher, and the response after administration of contrast material was greater. Nevertheless, the duration of the response was the same as in the control group, and the enzyme levels of all patients returned to their pre-DSA baseline levels.