CHICAGO—Use of sodium bicarbonate for hydration during coronary angiography for patients with kidney disease did not reduce the risk of developing serious kidney problems related to the use of contrast agents, compared to use of sodium chloride, according to a study in the September 3 issue of JAMA.
Nephropathy (disorder involving the kidneys or kidney function) is a known complication of exposure to iodine used as a contrast agent during angiography. Contrast-medium induced nephropathy is a common cause of kidney failure associated with prolonged hospitalization, increased health care costs and substantial illness and death. The reported incidence of contrast-induced nephropathy ranges from 2 percent in low-risk populations to 50 percent in high-risk populations. Animal models of kidney failure and one randomized clinical trial suggests that hydration with sodium bicarbonate may be an effective therapy for prevention of contrast-induced nephropathy, according to background information in the article.
Somjot S. Brar, M.D., of Columbia University Medical Center, New York, and colleagues conducted a study to evaluate the effect of sodium bicarbonate on the prevention of contrast medium–induced nephropathy. The randomized, controlled trial included 353 patients with moderate to severe kidney disease who were undergoing coronary angiography. Patients were randomized to receive either sodium chloride (n = 178) or sodium bicarbonate (n = 175), administered before, during and after coronary angiography. The median (midpoint) patient age was 71 years, and 45 percent of the patients had diabetes mellitus.
Overall, contrast-induced nephropathy assessed by estimated glomerular filtration rate (GFR; the flow rate of filtered fluid through the kidney) occurred in 13.9 percent (45/323) of the patients. The group receiving sodium chloride hydration had a 14.6 percent (24/165) incidence vs. 13.3 percent (21/158) in the sodium bicarbonate group. In patients randomized to receive sodium bicarbonate vs. sodium chloride, the rates of death, dialysis, heart attack, and cerebrovascular events did not differ significantly at 30 days or at 30 days to 6 months.
“The results of this study do not suggest that hydration with sodium bicarbonate is superior to hydration with sodium chloride in patients with moderate to severe chronic kidney disease who are undergoing coronary angiography. The overall incidence of contrast-induced nephropathy among patients was 13.9 percent and did not differ by treatment assignment. The frequency of clinical adverse events did not significantly differ between groups. Any true difference between the hydration strategies is likely to be small and not clinically significant,” the authors conclude.
(JAMA. 2008;300:1038-1046. Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.