Nephropathy related to computed tomography in emergency department patients with serum creatinine <1.5 mg/dL

정상 혈청 크레아티닌을 가진 응급실 환자에서의 조영제 연관 신증

Background: Contrast-induced nephropathy (CIN) can cause serious adverse effects. To reduce the occurrence of CIN related computed tomography (CT) in emergency patients, we assessed the respective roles of serum creatinine (SCr) alone and estimated glomerular filtration rate (eGFR) as an early predictor for CIN related CT. Methods: For patients with SCr <1.5 mg/dL who underwent CT in emergency department (ED) between September 2012 and October 2013, we assessed the prevalence of CIN and its adverse effects. The Modification of Diet in Renal Disease Study (MDRD) and Cockcroft-Gault (CG) formula was used for the calculation of eGFR. Practical calculation was performed by electronic medical record (EMR) system for MDRD and internet calculating service for CG. And we investigated the prevalence of CIN in eGFR $<60mL/min/1.73m^2$ before CT. Results: A total of 1,555 patients were enrolled. The prevalence of CIN after CT was 4.6% and it showed correlation with renal deterioration, increased in-hospital mortality, and prolonged hospitalization. Despite baseline SCr <1.5 mg/dL, among enrolled patients, 11.3% as MDRD equation and 29.5% as CG formula were $<60mL/min/1.73m^2$ and in this condition, the prevalence of CIN was significantly high (odds ratio was 2.87 [1.64-5.02] as MDRD equation and 2.03 [1.26-3.29] as CG formula). Conclusion: Just SCr <1.5mg/dL was not appropriate to recognize preexisting renal insufficiency, but eGFR using MDRD equation was useful in predicting the risk of CIN related CT in ED. Using EMR, calculation of eGFR can be easier and more convenient.