SAT-156 USING KINETIC GLOMERULAR FILTRATION RATE TO CALCULATE THE RENAL ANGINA INDEX

Abstract

Reliable prediction of acute kidney injury (AKI) has the potential to optimize its treatment. Recently Goldstein SL et al. (Clin J Am Soc Nephrol. 2010;5: 943–949.) proposed an empiric clinical model of renal angina to identify critically ill children who would be at higher risk of AKI. Using patient demographic factors and early signs of injury, renal angina aims to delineate patients at risk for subsequent severe AKI (AKI beyond the period of functional injury) versus those at low risk. In children the combination of the renal angina index (RAI) and AKI biomarkers has an excellent diagnostic performance. We aimed to assess the performance of a modified renal angina index (using kinetic glomerular filtration rate) in a cohort of adult critically ill patients at risk of AKI. We included 208 consecutive patients admitted to our medical ICU. Serum creatinine (sCr) was measure every 24 hours for 7 consecutive days following ICU admission. RAI was calculated 24 hours after ICU admission (day 1) using the following formula (Figure 1): Risk level (presence of sepsis, use of vasopressors and/or use of invasive mechanical ventilation, and presence of diabetes mellitus) x Injury level (changes in kidney function based on kinetic glomerular filtration rate (KeGFR). KeGFR was calculated from the change in consecutive values of sCr using the formula developed by Chen S. (J Am Soc Nephrol 2013; 24: 877–888). We used the KDIGO AKI sCr criteria to diagnose AKI. In patients with no baseline sCr available we back calculated baseline sCr using MDRD equation (for an eGFR = 75 ml/m/1.73m2). Based in our previous report (J Am Soc Nephrol 26: SA-PO 0193, 669A; 2015) we analyzed if a RAI score ≥ 6 points could predict subsequent AKI (after 48 hours). From the 208 patients enrolled in the study 101 patients developed AKI (48.6 %). Age, baseline sCr, and eGFR (CKD-EPI) we not different between patients with AKI and patients without AKI. At 24 h post ICU admission patients with AKI had lower KeGFR (47.7 ml/m vs. 81.1 ml/m; p < 0.0001). A renal angina index ≥ 6 points was able to identify individuals who developed AKI after 48 hours of ICU admission, with a ROC-AUC of 0.697 [95% CI 0.626-0.769], p < 0.0001. A renal angina index of ≥ 6 points had an odds ratio of 9.9 (95% CI 2.65 – 37.11; p < 0.0001) for subsequent development of AKI after 48 h of ICU admission. The RAI provides a clinically feasible methodology to identify critically ill patients at high risk of developing AKI before a rise in serum creatinine occurs. This tool would permit the early identification of AKI to initiate preventive and treatment strategies minimizing extension of kidney injury.