In view of the growing literature attributing increased short and long adverse events in terms of morbidity and mortality after even small and transient rise of SCr after CM exposure in CA; the current study highlights the need for careful assessment of baseline demographic criteria (whether patient or contrast- related) to calculate a predictive risk score based on the accumulation of risk factors that increase the incidence of CI-AKI with its serious sequences.
A standard definition of CI-AKI combining (both or either) a relative threshold (increase in creatinine of ≥ 25%) and an absolute threshold (increase in creatinine of ≥ 0.3 or mg⁄dL) from baseline values is more sensitive but less specific to identify this entity, emphasizing the need of combination of biomarkers in AKI setting.
Our study revealed that eGFR was more precise to predict CI-AKI in patients with normal baseline SCr, whereas SCr outperformed eGFR in patients with CKD, It should be noted however that eGFR is less reliable to detect acute changes in the setting of AKI, A3 (severe albuminuria) was found to be a significant risk factor in the studied cohort especially in those with hypoalbuminemia; reflecting both advanced CKD and diminished intravascular volume.
This works emphasizes the value of simple, readily available variables by both univariate and multivariate analysis (including: CKD, age over 75, DM +/- hyperglycemia, anemia, female gender, CHF, hypotension and the characteristics/volume of CM) when assigned a weighted score based on integer values to detect high risk group amenable to prophylactic interventions, whether based on model (A) using SCr or model (B) using eGFR by modified Levy MDRD equation.
The presence of an underlying CKD cannot be more overemphasized, given the fact that it is the single, most important, independent risk factor for future deterioration of already vulnerable kidneys after CA.
Hyperglycemia at time of CA is more risky for CI-AKI regardless the previous diabetic state.
Elderly are more prone to CI-AKI especially in the study patients over 75 years old.
As regard the type of CM, the currently available conflicting evidence makes it hard to give preference to LOCM versus IOCM in terms of osmolarity and viscosity.
Every effort should be exerted to minimize exposure to CM, unless benefit overweighs risk, as such; the use of the smallest amount is advised with proper spacing between exposures when repeated CM exposure deemed necessary.
This study highlighted that optimization of volume status is the core element in preventive strategies; i.v. isotonic fluid administration is the only independent measure to ameliorate the adverse outcomes of CI-AKI.
In our study, Sodium Bicarbonate has a marginal benefit over Normal saline, in theory the added antioxidant and free scavenger properties with alkalization of urine support this notion, especially in view of the growing concern about the increased risk of AKI with Normal saline employment due to its high Chloride content
In our study, pharmacological agents provided insignificant benefit to ameliorate CI-AKI, nevertheless; NAC when added to Sodium Bicarbonate containing fluids may be beneficial.
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