Indication
Contrast induced or associated AKI is felt to be a real albeit rare entity. The most important risk factor seems to be pre-existing severe renal insufficiency (AKI or eGFR<30mL/min/1.73m2. The major preventative action to mitigate the risk of CIN is to provide intravenous volume expansion (see Hydration protocol). One possible protocol would be 0.9% saline at 100 ml/hr, beginning 6-12 hrs before contrast and continuing for 4-12 hours after contrast in the inpatient setting.
A study from JAMA printed in May of 2004 indicates that hydration with a bicarbonate solution may better prevent contrast induced nephropathy than NS hydration. Most renal failure is associated with metabolic acidosis and low urinary pH. NS may contribute to acidosis while the bicarbonate solution will buffer the pH.3. Subsequent studies have challenged this practice, and results are not definitive at this time. However, given the low cost and lack of side effects, it is unlikely to be harmful and could be added to the hydration regimen. Other practices, such as administration of N-acetyl cysteine, are not supported by the literature. Cessation of nephrotoxic medications may also be helpful when feasible.
Administration/Dosing
Solution: 150 mEq NaHCO3 in 1000cc D5W
1 hour prior to contrast: Initial IV bolus – 3ml/kg/hour x 1 hour
After 1 hour bolus: 1ml/kg/hour during contrast exposure and 6 hours post contrast.
References
- Levy EM, Viscoli CM, Hurwitz RI. The effect of acute renal failure on mortality: a cohort analysis. JAMA. 1996; 275: 1489-1494.
- McCullough PA, Wolyn R, Rocher LL, et al. Acute renal failure after coronary intervention. Am J Med.1997; 103: 368-375.
- Merten GJ, et al. Prevention of contrast-induced nephropathy with sodium bicarbonate: a randomized controlled trial. JAMA. 2004; 291: 2328-2334.
- 2004/Lisa Semmann, R.N., M.S., Interventional Radiology NP