Recommendations from others
The American College of Radiology recommends using low-osmolality contrast media for patients with renal insufficiency, particularly those with diabetes.9 Clinical Evidence found support for the use of low-osmolality contrast media, periprocedural hydration, and acetylcysteine as interventions to reduce the risk of contrast nephropathy.10
Clinical Commentary
Avoid radiocontrast agents when possible; consider hydration and acetylcysteine
Richard A. Guthmann, MD
Illinois Masonic Family Practice Residency, University of Illinois at Chicago
The best prevention of contrast nephropathy is to avoid radiocontrast agents whenever possible. Ultrasound, MRI, or CT scanning without radiocontrast can often provide adequate information. However, when contrast agents must be used for high-risk patients, lower doses and iso-osmolal nonionic agents should be considered, and serial studies should be spaced out.
Adequate hydration and avoidance of drugs with renal effects, including nonsteroidal anti-inflammatory drugs, diuretics, and angiotensin-converting enzyme inhibitors, can decrease the risk of contrast nephropathy for patients requiring a contrast study. Patients can be hydrated and their medicines held starting the day before the procedure. For patients with any risk factors for contrast nephropathy, acetylcysteine should also be administered. Sodium bicarbonate can also lower the risk of nephropathy by administering it at the time of the procedure.
Contrast nephropathy has often been defined as an immediate increase in creatinine greater than 25%. The clinical significance of small transient elevations in creatinine is unclear. Furthermore, the wide variability reported in the incidence of contrast nephropathy results from differences in the presence of risk factors. Therefore, it is important to assess each patient’s risk individually and undertake additional preventive measures accordingly.