Objective To compare different blood purification techniques on serum fibroblast growth factor 23(FGF -23)scavenging effect in patients undergoing maintenance hemodialysis (MHD),in order to choose the best blood purification method for clinical maintenance hemodialysis patients.Methods 60 MHD patients were randomly divided into hemodialysis group (HD),hemodiafiltration group (HDF)and HD +HP group,20 cases in each group. Three groups of patients in the observation 1st start of treatment and observation at the end of the last treatment were detected cacium,phosphorus,FGF -23,intact parathyroid hormone(iPTH).Results After treatment,HD group and HDF group,Ca:t =0.29,P =0.77;P:t =1.65,P =0.11;iPTH:t =16.85,P =0.00;HD group and HD +HP group:Ca:t =0.20,P =0.84;P:t =2.62,P =0.01;iPTH:t =42.64,P =0.00;HDF group and HD +HP group:Ca:t =0.09,P =0.92;P:t =2.18,P =0.04;iPTH:t =31.41,P =0.00.After treatment,FGF -23 in the three groups were decreased significantly than before treatment,and the HD +HP group decreased most significantly(HD group and HDF group,t =4.47,P =0.00;HD group and HD +HP group:t =8.06,P =0.00;HDF group and HD +HP group:t =3.20,P =0.00).Conclusion HD +HP treatment can effectively remove phosphorus maintenance dialysis patients and FGF -23.

The artile introduced aformula that that is derived electrical re- sponse from particles size when it pass through aperture according to the principe.The result is identical with the coulter's formula and it has universality.