Sodium Bicarbonate Prevents Contrast-Induced Nephropathy in Addition to Theophylline: A Randomized Controlled Trial

In this study, we investigated whether hydration with sodium bicarbonate is superior to hydration with saline in addition to theophylline (both groups) in the prophylaxis of contrast-induced nephropathy (CIN). It was a prospective, randomized, double-blinded study in a university hospital on 2 general intensive care units (63% of investigations) and normal wards.After approval of the local ethics committee and informed consent 152 patients with screening serum creatinine 1.1mg/dL and/or at least 1 additional risk factor for CIN undergoing intravascular contrast media (CM) exposure were randomized to receive a total of 9mL/kg bicarbonate 154mmol/L (group B; n=74) or saline 0.9% (group S; n=78) hydration within 7h in addition to intravenous application of 200mg theophylline. Serum creatinine was determined immediately before, 24 and 48h after CM exposure. As primary endpoint we investigated the incidence of CIN (increase of serum creatinine 0.5mg/dL and/or 25% within 48h of CM).Both groups were comparable regarding baseline characteristics. Incidence of CIN was significantly less frequent with bicarbonate compared to sodium hydration (1/74 [1.4%] vs 7/78 [9.0%]; P=0.035). Time course of serum creatinine was more favorable in group B with decreases in serum creatinine after 24h (-0.084mg/dL [95% confidence interval: -0.035 to -0.133mg/dL]; P=0.008) and 48h (-0.093mg/dL (-0.025 to -0.161mg/dL); P=0.007) compared to baseline which were not observed in group S.In patients at increased risk of CIN receiving prophylactic theophylline, hydration with sodium bicarbonate reduces contrast-induced renal impairment compared to hydration with saline.