Systematic Review of Intravenous Contrast-Induced Nephropathy and Prophylaxis With Hydration

Despite the extensive body of literature on post-contrast acute kidney injury and prophylaxis, there is ongoing disagreement on the appropriateness of intravenous contrast administration and prophylactic measures in patients with poor renal function. Existing reviews indiscriminately include data from both historical high-osmolar (HOCM) as well as modern low- (LOCM) and iso-osmolar contrast media (IOCM). This systematic review assesses existing literature on contrast-associated kidney injury in adults (defined as individuals over 15 years of age) from intravenous (IV) iodinated LOCM/IOCM for computed tomography (CT) and prophylactic hydration with saline. Studies were searched on PubMed, Medline/Ovid, Cochrane and the University of Auckland Library. Papers were separated into trials and non-trials, with the references of non-trial articles followed until the original trial was identified, and duplicate patient groups were removed. The quality of studies were assessed using the GRADE system. Of 1253 potentially relevant studies, no high quality studies were identified. There were 13 moderate to low quality studies relating to contrast-associated acute kidney injury (CA-AKI), with the remaining assessed as very low quality. Inferences based on the moderate to low quality studies suggest that although contrast-induced acute kidney (CI-AKI) is a real phenomenon, the effect is not of a magnitude that is clinically significant for stable patients irrespective of baseline renal function. There was only a single low quality study for prophylactic IV hydration with saline, with the remaining studies being of very low quality.