Generally, a contrast medium is used when performing a CT scan or radiographic tests such as angiography because it heightens image clarity and can increase diagnosis accuracy. Despite these advantages, contrast media can cause allergic reactions in the body or a decline in renal function. Therefore, they should be handled carefully and explained sufficiently to the patient. For intensive care patients, the use of contrast agents has been revealed as a major cause of acute renal damage, and many studies have investigated this complication by examining incidence rates and prevention strategies. Hypothesis: Among intensive care patients, the group in which a contrast medium was used will have a higher risk of renal function decline compared with the group in which a contrast medium was not used, and, hence, the use of contrast media becomes a cause of renal function deterioration. Categorizing patients with renal function decline according to the new RIFLE criteria can have an association with the prognosis of intensive care patients, such as hospitalization period and death rate, which can promote faster intervention.

Inclusion Criteria:

• For the 5 years from January 2008 to December 2012, patients in whom a contrast medium was used in the intensive care unit were examined.

Exclusion Criteria:

• For the 5 years from January 2008 to December 2012, patients in whom a contrast medium was not used in the intensive care unit were examined.

RIFLE (Risk, Injury, Failure, Loss, and End-stage kidney disease) categorization and the existing classification method were used to compare their predictive value for acute renal damage related to contrast media.