THE EFFECT OF CONTRAST AGENTS ON RENAL-FUNCTION

Contrast agent nephropathy accounts for a substantial number of hospital acquired incidences of acute renal failure and the functional damage induced may sometimes be irreversible. The true incidence of the complication is still uncertain but seems to be low in patients with normal renal function. Among numerous risk factors proposed, pre-existing renal failure is the most important. Diabetes only seems to be a significant risk when there is pre-existing renal functional deficiency. Among four main theories for the mechanism of contrast agent nephropathy, interest is mainly focused on post contrast vasoconstriction and direct tubulotoxicity of the contrast agent. No dramatic decrease in the overall incidence of contrast agent nephropathy has been observed following the change from ionic to non-ionic agents. However, several recent clinical trials confirm that non-ionic contrast agents are less nephrotoxic than ionic agents in patients with pre-existing renal insufficiency.