Managing the risk associated with use of contrast media for computed tomography

Contrast agents are widely used in patients undergoing diagnostic and therapeutic imaging procedures. In recent years, there has been a significant increase in the use of iodinated contrast media (CM) due to the growing number of computed tomography (CT) procedures. Although contrast agents are generally well-tolerated, some patient subsets are at an increased risk of complications from CM. Patients at risk include those with a history of adverse reactions to CM, asthma or severe allergies, impaired renal function, older age, dehydration, congestive heart failure, or concurrent use of some drugs. Although the incidence of CM-associated complications cannot be eliminated, the chances of developing severe adverse reactions can be reduced by incorporating a number of management strategies into clinical practice. Patients at risk for acute adverse reactions can undergo pre-medication with corticosteroids, eventually associated with anti-histamines, although opinion is divided whether this prophylaxis should be used with non-ionic CM. Patients who have been identified as at risk for contrast-induced nephropathy (CIN) should be well-hydrated and have nephrotoxic medications withdrawn prior to CM exposure. Contrast dose should be decreased, as the risk of developing CIN is dose-dependent. For patients with pre-existing renal insufficiency, use of low-osmolar or iso-osmolar CM is preferable to use of high-osmolar CM. Simple strategies for preventing the risk of adverse reactions are reviewed.