Intravascular radiographic contrast media: issues for family physicians

Family physicians frequently order and in some instances supervise diagnostic tests using intravascular radiographic contrast media.

MEDLINE database was searched from 1966 to the present using the key terms "contrast media," "adverse reaction," "anaphylaxis," "anaphylactoid," "nephropathy," "renal failure," "kidney failure," and "MRI" in combinations. Other sources were found by back referencing these articles and in recent texts.

The adverse reactions likely to be encountered in most patients are acute anaphylactoid and cardiovascular reactions, delayed reactions, and renal effects. Mild acute reactions usually require no treatment, but if more severe reaction symptoms occur, emergency treatment is indicated. Acute reactions can be prevented or reduced by close attention to risk factors and pretreatment. Delayed reactions seldom require specific treatment. The type of contrast agent used might lessen the risk of immediate reactions. Contrast-associated nephropathy is most likely to occur in patients who have preexisting renal disease, heart failure, and volume depletion. Optimization of precontrast hydration can lessen the renal effects of contrast material. Magnetic resonance imaging contrast agents might be safer, because of smaller volumes administered, but adverse reactions have occurred.