Careful choice of iodine contrast can spare sensitive kidneys

Choosing an iso-osmolar dimeric contrast agent can reduce the risk of damage to kidneys in patients with diabetes or impaired renal function, according to a multinational study.

Researchers in 17 centers evaluated serum creatinine output for 135 patients with impaired kidney function in a double-blinded study of iodixanol, an iso-osmolar nonionic dimeric contrast medium, and iohexol, a low-osmolar nonionic monomeric contrast medium.

Compared with a baseline reading, patients given iodixanol had an average peak increase of 11.2 mmol/L of creatinine during the next three days. For patients given iohexol, the increase was 48.2 mmol/L. Only 3% of patients given iodixanol crossed the threshold for nephrotoxicity, compared with 26.2% for iohexol patients.

The result, according to lead author Dr. Peter Aspelin of Huddinge University Hospital in Stockholm, was that patients given iodixanol were 11 times less likely to experience nephrotoxicity. The findings of the Nephrotoxicity in High Risk Patients study were published recently in the New England Journal of Medicine and presented at the European Congress of Radiology.

"The risk of nephropathy is already high in patients with diabetes mellitus," he said. "Iodixanol can lower that risk."