Administering a sodium bicarbonate solution before injecting radiographic contrast material may reduce the risk of nephropathy, according to a new study. Contrast-induced nephropathy accounts for more than 10% of hospital-acquired renal failure. Researchers believe that increased urinary pH reduces oxidative injury in the kidney.
Researchers followed patients undergoing diagnostic or interventional procedures using the contrast agent iopamidol. All patients had stable renal insufficiency, with creatinine levels between 1.1 and 8 mg/dl. The patients were randomly assigned to receive either a sodium bicarbonate or sodium chloride infusion for 1 hour before their procedure and up to 6 hours after the procedure.
Contrast-induced nephropathy occurred in just 1.7% of those in the bicarbonate group, compared with 13.6% of those in the sodium chloride group. Researchers defined contrast-induced nephropathy as an increase in serum creatinine of 25% or more within 2 days of contrast administration.
Because the bicarbonate solution was clearly superior, researchers stopped the study early. They believe that sodium bicarbonate infusions are a simple, inexpensive, and low-risk alternative to other drugs and treatments designed to protect kidney function, such as N-acetylcysteine or hemofiltration.
"Prevention of Contrast-Induced Nephropathy with Sodium Bicarbonate," JAMA, G. Merten, et al., May 19, 2004.