Evaluation of different sodium bicarbonate regimens for the prevention of contrast medium-induced nephropathy

INTRODUCTION: The rapid decline in renal function caused by radiographic contrast agents usually is transient, but it can result in chronic kidney disease. The pathophysiology of contrast-induced nephropathy (CIN) is poorly understood, but it may include acute hypoxia-induced oxidative stress and free radicals generated within the acid environment of the renal medulla. Thus, the alkalization of urine by sodium bicarbonate has been regarded as resulting in the reduction of CIN. The aim of this study was to determine whether a long-duration sodium bicarbonate regimen is more effective than a short-duration regimen in reducing CIN. METHODS: One hundred patients were assigned randomly to treatment with sodium bicarbonate solution using either the short regimen (intravenous bolus 3 mL/kg/h of 166 mEq/L sodium bicarbonate for 1 hour immediately before radiocontrast) or the long regimen (initial intravenous bolus of 3 mL/kg/h of 166 mEq/L sodium bicarbonate for 6 hr). Patients with renal dysfunction (estimated glomerular filtration rate [eGFR], 60 mL/min/1.73 m(2) or less) who underwent elective or emergent coronary angiography (CAG) with/without percutaneous coronary intervention (PCI) at Nephrology Department (Theodor Bilharz Research Institute) were enrolled in the study. Data were analyzed by SPSS version 12, using Kruskal Wallis, ANOVA, Chi square test and Spearman rank correlation coefficient. RESULTS: There was a significant increase in serum creatinine and a decrease in eGFR 48 hr post-intervention in group 1 (short regimen) with no statically difference regarding those parameters group 2 (long regimen). Serum potassium clearly was decreased significantly post procedure in both groups. CONCLUSIONS: The results of our study indicated that the long regimen of bicarbonate supplementation was a more effective strategy to prevent CIN than the short regimen.