Contrast-Induced Nephropathy After Cardiac Catheterization: Risks & Understanding

Renal (or kidney) failure caused by a heart catheterization is also called contrast-induced nephropathy. Contrast, a medication given intravenously to view arteries with an x-ray, has the potential to harm the kidneys, especially if kidney function is poor before the test.

Definition

• Creatinine is measured by a simple blood test.

  Contrast-induced nephropathy is defined as an increase by 25 percent over baseline of the creatinine level in the blood. Creatinine, if elevated, indicates kidney damage.

Risk Factors

• Fixed (or non-modifiable) risk factors for developing kidney failure after a heart catheterization include: older age, diabetes, pre-existing kidney failure, and kidney transplant. Anemia, dehydration, and medications affecting the kidneys comprise some of the modifiable risk factors.

Treatment

• If contrast-induced kidney failure occurs, supportive treatment is given until the condition resolves. Few patients need hemodialysis.

Prevention/Solution

• Prevention of kidney failure focuses on limiting the risk factors prior to the procedure. Intravenous hydration with saline is the most widely accepted preventative intervention. Pre-test administration of oral N-acetylcysteine (Mucomist) or bicarbonate infusions have produced promising results, according to the Cleveland Clinic Journal of Medicine.

Application

• A careful risk-benefit analysis performed before heart catheterization prevents some cases of contrast-induced kidney failure from occuring.