Clinical Trial of Sodium Bicarbonate to Prevent Contrast-Induced Nephropathy

The use of contrast media is more frequent as new diagnostic and therapeutic procedures are developed. As a consequence, the occurrence of acute renal failure (ARF), also known as contrast-induced nephropathy, is more frequently seen after the realization of these procedures, representing about 10% of all in-hospital ARF. The importance of preventing this complication is related with its strong association with higher morbidity and mortality rates in patients who present it. A number of drugs and interventions have been studied for preventing contrast-induced nephropathy, including intravenous hydration with normal and hypotonic saline solutions, oral hydration, mannitol, diuretics, dopamine and its antagonists (fenoldopam), calcium antagonists, theophylline, N-acetylcysteine, natriuretic atrial peptide and hemodialysis after or during contrast media administration. There is only one study in humans that demonstrates the utility of the sodium bicarbonate to prevent the contrast-induced nephropathy, showing a reduction in the incidence of this complication of about 13.6%. Although this result could seem convincing, its relevance has been questioned because the definition used by the authors as contrast-induced nephropathy was an increase of 25% from basal creatinine. Although when compared, the absolute differences between basal and after-procedure creatinines were not statistically significative, the sample size was small and the participants were low-risk patients to develop contrast-induced nephropathy. It is also important to note that the control group was hydrated with a dextrose 5% solution with 154 mEq of NaCl, although today's most accepted prevention therapy is intravenous hydration with normal saline solution. Comparison: Hydration previously, during and afterwards contrast media administration with normal saline solution (0.9%), compared to hydration previous, during and afterwards contrast media administration with a solution made of normal saline and sodium bicarbonate.