Background Fluctuation of Kidney Function Versus Contrast-Induced Nephrotoxicity

Abstract

We identified a high incidence of acute kidney injury among control subjects undergoing unenhanced CT. The incidence of creatinine elevation in this group was statistically similar to that in the isoosmolar contrast medium group for all baseline creatinine values and all stages of chronic kidney disease. These findings suggest that the additional risk of acute kidney injury accompanying administration of contrast medium (contrast-induced nephrotoxicity) may be overstated and that much of the creatinine elevation in these patients is attributable to background fluctuation, underlying disease, or treatment.

Contrast‐induced Acute Kidney Injury: Time for a Step Backward

“…Mortality, incidence of CKD, and requirements for RRT did not differ between contrast-exposed and unexposed patients. Our study, similar to many others, [4][5][6][7] has found equivalent incidences of AKI between contrast-exposed and unexposed patients and challenged whether the current definition of CIAKI represents a true clinical entity.…”

Contrast Material–induced Nephrotoxicity and Intravenous Low-Osmolality Iodinated Contrast Material: Risk Stratification by Using Estimated Glomerular Filtration Rate

“…Our patient population was drawn from a comprehensive database of all CT substantial fraction of patients who, regardless of exposure to contrast material, experience post-CT AKI (2,16,17). This contributes noise to any CIN analysis, and many patients may be assigned a diagnosis of CIN when other nephrotoxic agents or conditions are to blame (16,17).…”

“…This contributes noise to any CIN analysis, and many patients may be assigned a diagnosis of CIN when other nephrotoxic agents or conditions are to blame (16,17). The nonenhanced CT population has been used as a way to control for baseline post-CT AKI risk (2,(5)(6)(7)(8)(9)(10), but this is insufficient because it does not address the numerous risk factors for CIN (eg, diabetes mellitus or pre-CT AKI), in addition to chronic renal insufficiency, that may cause iodinated contrast material to be withheld. Because a large fraction of patients who are examined with nonenhanced CT have nephrotoxic risk factors that are directly responsible for the clinical avoidance of contrast material, the nonenhanced and contrast-enhanced CT populations are fundamentally different.…”

“…In addition, it is known that estimated glomerular filtration rate (eGFR) is more accurate than SCr at T he incidence of contrast materialinduced nephrotoxicity (CIN) in the setting of intravenously (IV) administered low-osmolality contrast material (LOCM) (ie, that administered routinely for contrast-enhanced computed tomography [CT] studies) is controversial (1)(2)(3)(4). In recent years, retrospective studies have shown similar rates of post-CT acute kidney injury (AKI) in nonenhanced and contrast-enhanced CT populations (2,(5)(6)(7)(8)(9)(10), which led some to question the incidence of CIN in this setting and whether it occurs at all (3,4). This topic has considerable clinical relevance because concern for renal toxicity is a main reason to avoid IV contrast material in some patients (11)(12)(13)(14)(15).…”

Contrast “induced” versus “associated” acute kidney injury: take care with the definition

“…And third, no control group of patients who were submitted to CT without CM was analyzed and compared with their population. This is a major flaw of the study because an increase in serum creatinine concentration has already been described in non-critically ill patients who had a CT scan without CM administration [5]. Performing such analyses would allow one to estimate the attributable impact of CM injection on renal function impairment.…”