Abstract: Objective To compare the influence of the urea generation factor (GFAC) modification on spKt/V, balanced Kt/V (eKt/V) and standardized Kt/V (stdKt/V), where eKt/V and stdKt/V were estimated from spKt/V. Methods Ninety- five hemodialysis patients who were dialyzed except three times per week or not 2- day preceding interdialysis interval for 3/week from the Peking University People's Hospital were included in this study. The value of spKt/V1 was estimated using GFAC=0.008, and eKt/V1 and stdKt/V1 were estimated. Using modified GFAC, spKt/V2, eKt/V2 and stdKt/ V2 were estimated. The spKt/V1, eKt/V1 and stdKt/V1 were compared with spKt/V2, eKt/V2 and stdKt/V2. Results There were significant differences between spKt/V1 and spKt/V2 (1.538±0.357 vs. 1.504±0.341), eKt/V1 and eKt/V2 (1.525±0.315 vs. 1.495±0.301), stdKt/V1 and stdKt/V2 (2.298±0.230 vs. 2.279±0.230), respectively (P<0.01). Conclusion Using GFAC= 0.008 in equation for patients who were not matched the urea kinetic model could overestimate spKt/V, and hence, using the modified GFAC based on the dialysis schedules and the day of blood drawn can be more accurately to estimate the spKt/V, eKt/V and stdKt/V.

Key words: renal dialysis, urea generation factor, single-pool Kt/V, equilibrated Kt/V, standard Kt/V