Abstract: Objectives To explore the relationship between the dialysis adequacy measured by online clearance monitoring (OCM)and Kt/V urea from pre- and post- dialysis blood samples, then establish formula to estimate Kt/V urea clearance by the online clearance monitoring, and analyze the clinical factors which affect the OCM. Methods OCM and Kt/V urea values from 111 maintenance hemodialysis patients were measured. The correlation between OCM and Kt/V urea values was analyzed by correlation assay. And formula to estimate Kt/V urea clearance by the online clearance monitoring was established. Clinical factors which affect
the value of Kt/V measured by OCM were analyzed by multiple linear regression. Results Dialysis dose measured by OCM was lower than Kt/V urea, correlating well with Kt/V urea (r=0.676, P＜0.001). Conclusions Dialysis dose measured by OCM goes hand in hand with Kt/V urea. The clinical factors that affect OCM include height, post-dialysis weight and body surface area.

Key words: Hemodialysis, Adequacy, Online clearance monitoring