Abstract:

ABSTRACT   Objective: Continuous veno-venous hemofiltration (CVVH) can affect the serum concentrations of usually used biomarkers to indicate renal function, like urea, creatinine (SCr) and cystatin C (Cys C). In this study, what extent (dose and duration) CVVH could affect the concentrations of urea, SCr and Cys C independent on renal function change was investigated. Methodology: Fifteen patients with oliguric acute AKI requiring CVVH were enrolled. Seven of them received CVVH in predilution mode at dose of 2L/hr and eight received CVVH in predilution mode at dose of 4L/hr. Samples were obtained from the afferent and efferent lines of the extracorporeal circuit and from the ultrafiltrate line at 4 different time points (0, 4, 12 and 24h) for measurement of urea, SCr and Cys C. The changes of serum levels of biomarkers over time, clearance of biomarkers and area under the curve (AUC) were analyzed. Results: The serum levels of urea, SCr and Cys C were gradually decreased at 4, 12 and 24hr during CVVH at dose of 2L/hr. The mean decreases of urea, SCr and Cys C at 24hr were 50.0%, 47.3% and 33.0% respectively. The decreases of Cys C at 24hr were significantly less than that of SCr and urea (both P<0.05). The mean clearance of urea, SCr and Cys C were 26.1, 24.9 and 10.1mL/min, and AUC (mg/L.h) were Urea 0.306, SCr 0.252 and Cys C 0.190 respectively. The serum levels of urea, SCr and Cys C were gradually decreased at 4, 12 and 24h during CVVH at dose of 4L/hr. The mean decreases of urea, SCr and Cys C at 24hr were 58.7%, 50.0% and 31.4% respectively. The decreases of Cys C at 24hr were significantly less than that of SCr and urea (both P<0.05). The mean clearance of urea, SCr and Cys C were 43.6, 42.4 and 23.7mL/min, and AUC (mg/L.h) were Urea 0.271, SCr 0.216 and Cys C 0.310 respectively.  Conclusion: The alteration of serum levels of Cys C during CVVH is comparable with SCr and urea.

Key words: continuous renal replacement therapy  , continuous veno-venous hemofiltration  , acute kidney injury