Contrast Nephrotoxicity Associated with Emergency CT scans

Cho, Young Soon; Chung, Tae Nyoung; Sohn, Dae Kon; Kim, Seung Ho

Abstract

PURPOSE
In the last 30 years, there has been a markedly increased use of iodinated contrast agents in diagnostic and interventional radiological procedures. Due to the possible side effect of nephrotoxicity of these radiocontrast agents, we investigated the incidence of nephrotoxicity and attempted to identify the patient groups at higher risk for contrast nephrotoxicity among the patients who underwent emergency computerized tomography.
METHODS
We reviewed the medical records of 1,572 patients who had undergone contrast computerized tomography at the Emergency Center, Yonsei Medical Center, from January to May 2002. We defined contrast nephrotoxicity as any increase in the creatinine value of more than 0.5 mg/dL (44 micromol/L) or 25% compared to the baseline value.
RESULTS
We found 21 patients (1.3%) who met the criterion for contrast nephrotoxicity: 13 patients with normal renal function, and 8 patients with a higher than normal creatinine value before contrast-enhanced computerized tomography. The incidence of contrast nephrotoxicity in the patient group with normal renal function was 0.8% (13/1551), compared to 38.1% (8/21) in the pre-existing renal insufficiency group. There were no statistical differences on the amounts of dye used and the frequencies of risk factors for contrast nephro-toxicity between the patients in pre-existing renal insufficiency group who developed nephrotoxicity and who did not. The renal function of all patients returned to the baseline value without dialysis or renal replacement therapy.
CONCLUSION
Pre-existing renal insufficiency is the most important risk factor for contrast nephrotoxicity. We need to take precautions and to have a proper protocol for the prevention of contrast nephrotoxicity in emergency care.