Inter- and Intra-Patient Cyclical Variability in Hgb Responses in Patients on Hemodialysis and Online Hemodiafiltraion

Objective: To study the variability in Hgb response to standard anemia management guidelines in hemodialysis patients. Methods: This is an observational prospective study on stable chronic dialysis patients. Baseline Hgb and iron studies were performed during the monthly anemia management rounds and repeated after a one-month cycle. ESA and IV iron dose adjustments were made according to a standard protocol. The variability in Hgb change and its relation to gender, type of ESA, dialysis modality, vascular access type, ESA and IV iron therapy adjustment and baseline hematological parameters were analyzed. Results: Of 222 patients included, 77.3% were on hemodialysis (HD) and 22.7% on hemodiafiltation (HDF). Darbepoetin was in 31.9% and EPO in 68.1% of the patients. Over the observation period, the ESA dose was unchanged in 40.8%, withheld in 8.3%, reduced in 18.8% and increased in 26.6 % while the Hgb level rose in 56.4%, dropped in 8.5 % and was unchanged in 35.5% of the patients. However, the overall frequency of patients with hemoglobin levels in the recommended range did no change (64.7% and 63.2% respectively (p= 0.83). Neither the magnitude nor the direction of ESA dose adjustment nor the change in Hgb level or its direction were affected by the ESA type, the dialysis type , the vascular access type or IV iron therapy given . No differences were noted between the HD and HDF groups in any of the parameters measured except that HD group required higher darbepoetin dose (56.6 ± 43 mcg versus 35.5 ± 30 mcg) in HDF group (p=0.031). No differences were noted between the patients using permcaths as vascular access and those with native grafts in any of the parameters measured except that the former group required higher darbepoetin dose (13915 ± 9635 iu and 10150 ± 8877 iu respectively p=0.02). Conclusion: Although there was no change in the proportion of patients with Hgb levels within the recommend range over the observation, period, the change in Hgb level was not always predictable by the ESA dose adjustment magnitude or direction. There was a significant increase in the number of patients h Hgb levels between >13 gms from 5.4% to 10.5% (p=0.0001). Patient on HD required higher darbepoetin dose than those on HDF despite similar hematological parameters findings and IV iron usage in both groups. Patient using Permcaths for vascular access required higher darbepoetin dose than those with native grafts despite similar hematological parameters findings and IV iron usage in both group.