Contrast nephrotoxicity.

Iodinated contrast media have some nephrotoxic potential but rarely cause significant renal failure in patients with normally functioning kidneys. Patients with existing renal impairment, with or without diabetes, those with current congestive heart failure of Class III or IV, those with reduced effective arterial volume (e.g., nephrotic, cirrhotic), or those receiving drugs that may impair renal function or increase contrast nephrotoxicity are at higher risk. Contrast nephrotoxicity may be clinically important in patients with other factors simultaneously affecting the renal response to contrast or in whom acute renal failure would seriously affect prognosis. The pathogenesis of contrast nephrotoxicity probably involves a combination of direct tubular toxicity and renal ischemic injury. Knowledge of the pathogenetic pathways is accumulating and is leading to the discovery of rational specific prophylactic measures to reduce the burden of nephrotoxicity. After the efficacy of these measures has been established, they should be considered for use in patients at high risk. Existing data indicate a limited role for the newer low-osmolality media for the prevention of nephrotoxicity.