Contrast-associated acute kidney injury is a myth: We are not sure

Use of Intravenous Iodinated Contrast Media in Patients with Kidney Disease: Consensus Statements from the American College of Radiology and the National Kidney Foundation

“…This definition is problematic because in most cases, "exclusion of other nephrotoxic factors" is not feasible or reliable (2). Consequently, many cases of AKI that are coincident with but causally unrelated to intravenous contrast media administration have been incorrectly attributed as contrast induced, thereby overstating the risks of intravenous contrast media administration (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)15). The vast majority of studies on this topic have not included a control group of similar patients who were not exposed to contrast media, making it impossible to separate causal from coincident AKI (20).…”

“…In such studies, the risk of CI-AKI has been estimated to be near 0% at eGFR greater than or equal to 45, 0%-2% at eGFR of 30-44, and 0%-17% at eGFR less than 30 mL/min/1.73 m 2 . These studies (1)(2)(3)(4)(5)(6)(7)(8)10,11,13) are underpowered to establish risk in patients with severe kidney disease, differ in their conclusions about risk in patients with eGFR less than 30 mL/min/1.73 m 2 (estimated CI-AKI risk range, 0%-17%), and are observational in design (ie, only known confounders can be addressed). There are no randomized trials differentiating CA-AKI from CI-AKI in patients with eGFR less than 30 mL/min/1.73 m 2 .…”

“…However, clinical decision making in patients potentially at risk for acute kidney injury (AKI) is often fraught with confusion, uncertainty, and heterogeneity. This is due in part to shifting perceptions regarding the true risks of modern contrast media (1)(2)(3)(4)(5)(6), improvements in scientific methodology used to study these adverse events (7)(8)(9)(10)(11)(12)(13), incomplete penetrance of new knowledge into scientific practice (14), latent bias related to historical precedent (1,2), uncertainty regarding the interpretation of recently conducted well-controlled observational studies (4)(5)(6), and differences in recommendations across radiology and medical subspecialties (15)(16)(17)(18).…”

Risk of post-contrast acute kidney injury in emergency department patients with sepsis

“…7,10 Nevertheless, it remains controversial whether an association exists between intravenous administration of contrast media during CT scans and the development of CA-AKI. [11][12][13] This controversy exists largely because the introduction of refined iso-or low-osmolar contrast agents has reduced the risk of AKI 14 and because the majority of previous studies on CA-AKI were performed in patients who underwent coronary angiography, [15][16][17] which utilises different dosages and routes of contrast administration relative to those of conventional contrast-enhanced CT scans. 18 Previous studies on CA-AKI in an emergency setting have been inconclusive.…”

Focus on critical care nephrology

“…A lot of debate has been ongoing lately on the evidence for a causal association between contrast administration and AKI [7]. An analysis using the Bradford-Hill criteria points to significant uncertainty on a causal link mainly based on the consistent neutral results of recent casecontrol trials using propensity score matching, the presence of alternative explanations for AKI in most patients, the variability in incidences suggesting a weak association and the absence of benefit in well-designed RCTs on preventive measures that are supposed to alleviate the pathophysiological pathways leading to contrast-associated AKI [8].…”