CONTRAST NEPHROTOXICITY

Iodinated contrast media have some nephrotoxic potential but rarely ca use significant renal failure in patients with normally functioning ki dneys. Patients with existing renal impairment, with or without diabet es, those with current congestive heart failure of Class III or IV, th ose 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 m ay be clinically important in patients with other factors simultaneous ly effecting the renal response to contrast or in whom acute renal fai lure would seriously affect prognosis. The pathogenesis of contrast ne phrotoxicity probably involves a combination of direct tubular toxicit y and renal ischemic injury. Knowledge of the pathogenetic pathways is accumulating and is leading to the discovery of rational specific pro phylactic measures to reduce the burden of nephrotoxicity. After the e fficacy of these measures has been established, they should be conside red for use in patients at high risk. Existing data indicate a limited role for the newer low-osmolality media for the prevention of nephrot oxicity.