A randomized trial of saline hydration to prevent contrast nephropathy in chronic renal failure patients

Contrast nephropathy (CN) is a common cause of renal dysfunction that may be prevented by saline hydration and by drugs such as theophylline or furosemide. Whether oral saline hydration is as efficient as intravenous saline hydration is unknown. The preventive efficacy of theophylline and furosemide for CN remains controversial. The purpose of the current study was to evaluate the efficacy of oral saline hydration and of intravenous saline hydration plus theophylline or furosemide for the prevention of CN.

We prospectively studied 312 patients with chronic renal failure (serum creatinine 201+/-81 micromol/l, Cockcroft clearance 37+/-12 ml/min/1.73 m(2)), who were undergoing various radiological procedures with a non-ionic, low osmolality contrast agent. Patients were randomly assigned to four arms. In arm A, patients received 1 g/10 kg of body weight/day of sodium chloride per os for 2 days before the procedure. In arm B, patients received 0.9% saline intravenously at a rate of 15 ml/kg for 6 h before the procedure. In arm C, patients received the same saline hydration as in arm B plus 5 mg/kg theophylline per os in one dose 1 h before the procedure. In arm D, patients received the same saline hydration as in arm B plus 3 mg/kg of furosemide intravenously just after the procedure.

Patients were well-matched with no significant differences at baseline in any measured parameters. Acute renal failure, defined as an increase in serum creatinine of 44 micromol/l (0.5 mg/dl), occurred in 27 out of 312 patients (8.7%). There was no significant difference between the rate of renal failure in the different arms of the study: five out of 76 (6.6%) in arm A, four out of 77 (5.2%) in arm B, six out of 80 (7.5%) in arm C and 12 out of 79 (15.2%) in arm D. No patient had fluid overload or a significant increase in blood pressure in the 2 days following the radiological procedure. The independent predictors of CN were diabetes mellitus, high baseline serum creatinine and high systolic blood pressure.

Oral saline hydration was as efficient as intravenous saline hydration for the prevention of CN in patients with stage 3 renal diseases. Furosemide and theophylline were not protective.