Contrast-induced acute kidney injury

Abstract

Contrast-induced acute kidney injury (CI-AKI) is a form of kidney damage by recent exposure of iodinated contrast media (CM) without another clear cause for AKI. Now serum creatinine-based definition is generally used; however, there are some problems on the definition and differentiation of CI-AKI. CM is known to induce a variety of alterations in the kidney. The new mechanism of direct tubular injury, specifically the role of inflammatory pathway, has recently been characterized to explain CI-AKI in clinical setting. This might lead to new therapeutic strategy. Both patient-related and procedure-related risk factors for CI-AKI have been identified, and volume depletion and chronic kidney disease (CKD) are known to be high risks for CI-AKI. It is increasingly recognized that old data from cardiac angiography studies may overestimate the risk of CI-AKI for patients undergoing intravenous contrast-enhanced studies. Recent well-designed studies addressed the incidence of CI-AKI after intravenous administration of CM for computed tomography was quite low. At present the only available preventive action to reduce the risk for CI-AKI is to provide intravenous volume expansion before, during, and after CM administration. Reevaluation of definition, the risk factors, the true impact, and preventative measures for CI-AKI are required in order to better understand CI-AKI.