Combination treatment reduces acute kidney injury due to infusion of contrast dye during cardiac catheterization
Research Activities, May 2010, No. 357
Contrast-induced acute kidney injury (AKI) is a serious possible side effect of the 1.3 million cardiac catheterizations and percutaneous coronary interventions (PCIs) in the U.S. each year. Up to 15 percent of PCI patients may develop contrast-induced AKI, with a fivefold increase of in-hospital and long-term mortality. Contrast media are fluids injected into the bloodstream to increase the image contrast of the heart or other anatomical structures that are not normally easily visualized. Contrast-induced AKI was reduced 35 percent by a combination treatment of N-acetylcysteine (NAC) plus sodium bicarbonate (NaHCO3), according to a new review. However, the review, a meta-analysis of 10 randomized controlled trials, found that a combination of NAC and NaHCO3 did not significantly reduce renal failure requiring dialysis.
Contrast-induced AKI is commonly defined as a 25 percent increase or a 0.5 mg/dl increase in serum creatinine from baseline within 48 hours of exposure. Researchers hypothesize that contrast-induced AKI results from direct toxicity to kidney tubules by a contrast medium or by renal hemodynamic changes. Patients with contrast-induced AKI had a 22 percent mortality rate compared with 1.4 percent for those without AKI.
Multiple strategies have been used independently to reduce contrast-induced AKI: hydration alone, NaHCO3 alone, NAC alone, and others. However, there has been a lack of consensus about the implementation of these strategies in practice, likely due to much confusion about their clinical efficacy. The authors recommend that the combination prophylaxis of NAC and NaHCO3 should be used in all high-risk patients (emergency patients or those with chronic kidney disease) and should be strongly considered for all interventional radio-contrast procedures. Their study was supported by the Agency for Healthcare Research and Quality (T32 HS00070).
See "Sodium bicarbonate plus N-acetylcysteine prophylaxis," by Jeremiah R. Brown, Ph.D., Clay A. Block, M.D., David J. Malenka, M.D., and others in the November 2009 JACC: Cardiovascular Interventions 2(11), pp. 1116-1124.