The National Kidney Foundation (NKF) and the American College of Radiology (ACR) have published an updated consensus statement to improve the care of adults with impaired kidney function requiring intravenous (IV) iodinated contrast media, which are commonly used for computed tomography (CT).
In the past, patients with reduced kidney function have been denied iodinated contrast media because of fears they might experience contrast-induced acute kidney injury (CI-AKI). This risk has been overstated, according to Matthew S. Davenport, MD, of Michigan Medicine in Ann Arbor, and fellow authors. AKI only temporally associated with contrast exposure has been conflated with true CI-AKI in uncontrolled studies. The real risk of CI-AKI remains unknown, according to the authors.
The updated consensus statement, published in Radiology, makes the following suggestions.
- Prophylaxis with IV normal saline is indicated for patients with AKI or an estimated glomerular filtration rate (eGFR) less than 30 mL/min/1.73 m2 who are not undergoing maintenance dialysis, as long as they are free of contraindications, such as heart failure. Existing research estimates that CI-AKI occurs in 0% to 17% of patients with low eGFR not on dialysis.
- If feasible, withhold nephrotoxic medications in high-risk individuals, including those with recent AKI, eGFR less than 30 mL/min/1.73 m2, and nonanuric patients undergoing maintenance dialysis (who have residual kidney function). For example, consider withholding nonsteroidal anti-inflammatory drugs, diuretics, aminoglycosides, amphotericin, platins, zoledronate, and methotrexate for 24 to 48 hours before and 48 hours after contrast exposure.
- Prophylaxis may be considered in high-risk patients with an eGFR of 30 to 44 mL/min/1.73 m2.
- Closely monitor eGFR in patients receiving nephrotoxic medications or undergoing chemotherapy before, during, and after contrast use.
- Do not initiate or alter renal replacement therapy solely for contrast media.
- A solitary kidney should not automatically preclude use of contrast media
- Avoid reducing contrast media dose below the diagnostic threshold.
There are no clinically relevant differences between using iso-osmolality and low-osmolality iodinated contrast media, the authors noted. Additional research, including in children, is still needed.
“It is important to recognize that in clinical practice, a multitude of factors are used to determine whether intravenous contrast media should be administered (eg, probability and necessity of an accurate diagnosis, alternative methods of diagnosis, risks of misdiagnosis, expectations about kidney functional recovery, allergic-like reaction risk),” Dr Davenport and his co-authors stated. “Decisions are rarely based on a single consideration (eg, risk of an adverse event specifically related to kidney impairment). Consequently, these statements should be considered in the context of the entire clinical scenario.”
Davenport MS, Perazella MA, Yee J, et al. Use of intravenous iodinated contrast media in patients with kidney disease: Consensus statements from the American College of Radiology and the National Kidney Foundation. Radiol. 2020;294:660-668. doi: 10.1148/radiol.2019192094