American College of Radiology and National Kidney Foundation publish cross-discipline guidance on administering iodinated contrast media in patients with kidney disease.
The risk of using intravenous iodinated contrast media in CT scans for patients with existing disease has been exaggerated, according to new consensus statements from the American College of Radiology (ACR) and the National Kidney Foundation (NKF).
The statements were published simultaneously in the Jan. 21 issues of Radiology and Kidney Medicine.
Although IV contrast is routinely used to augment the efficacy of CT in evaluating disease and pinpointing the best treatment options, patients with reduced kidney function routinely have contrast withheld or postponed due to the perceived risk of contrast-induced acute kidney injury (CI-AKI) where the contrast directly causes the harm. This frequently results in delayed treatment that causes morbidity or mortality in patients.
This problem largely stems from study design, said lead study author Matthew Davenport, M.D., associate professor of radiology and urology at the University of Michigan in Ann Arbor.
“Most studies looking at the use of contrast in patients with kidney disease have not included a control group of patients not exposed to contrast, so it was assumed that all kidney injuries happening around the time of contrast exposure were caused by the contrast,” he told Diagnostic Imaging. “The overstatement of risk exists because much of the kidney injuries that happen around the time of kidney studies are just coincidental. Patients don’t get a CT scan unless they’re already sick.”
In many cases, cancer, infection, inflammation, or nephrotoxic medication could be responsible for the kidney injury, he said. These instances – where kidney injury can’t be directly attributed to contrast media – are considered contrast-associated acute kidney injury (CA-AKI).
These consensus statements are intended to give both radiologists and nephrologists cross-specialty guidelines for how best to approach using contrast media in this patient population. Following these statements will not only result in more standardized care, but it will also ensure the clearest images and the most informed diagnoses for these patients.
“When doctors at the local level are trying to determine policies for treating patients with reduced kidney function, they now have guidelines approved by both disciplines that they can consult about what they should do,” he said.
Most importantly, although the true risk of CI-AKI remains unclear, the consensus statements do offer several directions:
In addition, the consensus statements warn providers against lowering contrast media dose below a known diagnostic threshold because it decreases diagnostic accuracy. Also, referring clinicians should also withhold nephrotoxic medications in high-risk patients.
Overall, the ACR and NKF drafted 15 recommendations: