025 ESTIMATES OF GLOMERULAR FILTRATION RATE IN THE CRITICALLY ILL WITH SEPSIS

Abstract

Category: Research in AKI (Basic, translational, clinical including clinical trials) Presenter: Assoc. Prof Azrina Md Ralib Keywords: Glomerular Filtration Rate, Cystatin C, Creatinine Accurate assessment of glomerular filtration rate (GFR) in ICU patients is very important for institution of supportive therapy, preventive therapy, early renal support, drug dosing modification or avoidance of nephrotoxic drugs. Kinetic estimate of GFR (keGFR) takes into account the changes of creatinine over time, creatinine production rate, and the volume of distribution, hence postulated to be a more accurate estimate of GFR in the acute setting, where there are rapidly changing kidney functions as in the critically ill. We evaluated the association of the keGFR with estimated GFR (eGFR) by conventional method. This is an interim analysis of a single centre, prospective observational study of critically ill patients. The study has been registered with the National Medical Research Register (NMRR-14-1897-21447) and has obtained ethics approval. Inclusion criteria were patients older than 18 years old with sepsis, defined as clinical infection and acute increase in SOFA score>2, and plasma procalcitonin>0.5ng/ml. Plasma creatinine and Cystatin C were measured at seven time points, and eGFR were calculated by the Cockcroft-Gault, MDRD, CKD-EPI, and eGFRCysC and they were compared to their keGFR equations. Twenty four patients were recruited so far, of which 10 (41.7%) had AKI. Two patients needed dialysis, and one died. keGFRCr strongly correlated with eGFRCKD-EPI equation in all patients at all time points (all r≥0.76, p<0.0001). On the other hand, keGFRCr only correlated well with eGFRMDRD and eGFRCG in AKI patients but less in patients without AKI. keGFRCysC strongly correlated with eGFRCysC in all patients at all time points (all r≥0.89, p<0.0001) keGFRCr and keGFRCysC were not strongly correlated (min r=0.29) eGFRCKD-EPI distribution had the greatest precision depicted by the narrower SD lines. Similarly, keGFRCysC had higher precision when compared to eGFRCysC. eGFRMDRD and eGFRCG had the least bias depicted by the mean difference nearest to zero. Both eGFRCKD-EPI and eGFRCysC distribution differed significantly from the keGFRCr and keGFRCysC, respectively (Wilcoxon sign rank test, p<0.0001). The new equation, keGFR strongly correlated with the eGFR by the CKD-EPI equation with the highest precision. In the absence of serial plasma creatinine measurement, eGFR is best estimated by the CKD-EPI equation. eGFR of Cystatin C also correlated well with its keGFR. Further study would involve analysis of their association with urinary creatinine clearance.View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT)