Analysis of radiocontrast-induced nephropathy by dual-labeled radionuclide clearance

This study was devised to develop a method of measuring the acute effects of radiocontrast media on renal function and assessing the relationship of the dose of radiocontrast media infused with the incidence of radiocontrast-induced renal failure. In addition, the drug adenosine phosphate-magnesium chloride (ATP-MgCl2) was evaluated as a renoprotective agent.

Eighteen patients with pre-existing renal impairment, (serum creatinine greater than 133 mumol/L) were randomized to receive a continuous infusion of ATP-MgCl2 or placebo before and during a radiocontrast procedure. Subjects were monitored with daily serum creatinine and with radionuclide renal clearance studies at baseline, during, and 24 hours after the radiocontrast procedure.

There was an initial deterioration in renal clearance in the entire study group (from 44.2 +/- 4.6 to 32.6 +/- 3.9 mL/min, P = .001) which was independent of the dose of radiocontrast infused. There was a persistent deterioration in renal clearance only in those who received greater than 135 mL of contrast media (from 48.6 +/- 7.8 to 37.1 +/- 3.9 mL/min, P = .05). There also was an increase in serum creatinine that persisted only in those subjects who received greater than 135 mL of contrast media (230 +/- 27 to 283 +/- 44 mumol/L, P = .01).

Persistent deterioration in renal function after radiocontrast administration appears to be dose-dependent and is not prevented by the use of ATP-MgCl2. Radionuclide techniques are useful in monitoring acute changes in renal function during radiocontrast procedures and may be of value in assessing renal impairment in future intervention studies.