Contrast-Induced Nephropathy and Prophylactic Administration of Sodium Bicarbonate with Coronary Angiography

Background: Coronary angiography is associated with a 4-15% chance of contrast-induced nephropathy (CIN). While the cause of CIN is still not understood, renal ischemia and free radical effects on tubular epithelial cells are thought to be responsible. In addition to increased hydration, the antioxidant properties of sodium bicarbonate are thought to decrease the direct toxic effects seen in CIN. The question of this treatment’s efficacy has been asked since its inception, and no definitive conclusion has been reached. The purpose of this systematic review is to compare and contrast the most current randomized trials, assessing the quality of the studies involved, and to give a practicing clinician a more complete understanding of the outcomes. Methods: Exhaustive search of available medical literature from 2006 to the present for randomized control trials regarding contrast-induced nephropathy in patients undergoing non-emergent coronary angiography. The reviewed studies examined the significance of sodium bicarbonate in addition to hydration versus hydration alone, measured by pre- and post-operative renal function. Results: The five studies reviewed do not agree on the efficacy of sodium bicarbonate administration for renal prophylaxis, although all state that increased hydration is the gold standard, and that sodium bicarbonate is not associated with increased adverse effects. Multiple studies showed no statistical significance of renal protection when compared to hydration alone, although methods of administration and several other confounders were identified when the trials were analyzed en masse. Conclusion: Repeated, definitive, single protocol studies have yet to determine the efficacy of sodium bicarbonate administration in patients undergoing cardiac angiography, but all current studies can agree that use of this compound for renal prophylaxis is not associated with an increased risk to the patient