The Role of Feedback Control Design in Developing Anemia Management Protocols

Individualized anemia management enhanced by ferric pyrophosphate citrate protocol

The optimal use of erythropoiesis-stimulating agents (ESAs) and parenteral iron in managing anemia in end-stage renal disease (ESRD) remains controversial. One-size-fits-all rule-based algorithms dominate dosing protocols for ESA and parenteral iron. However, the Food & Drug Administration (FDA) guidelines for using ESAs in chronic kidney disease recommend individualized therapy for the patient. This prospective quality assurance project was at a single hemodialysis (HD) center comprising three 6-month phases (A, B, C) separated by 3-month washout periods. Standard bi-weekly ESA dose titration and intravenous (IV) iron sucrose protocols were used in baseline Phase A, and ferric pyrophosphate citrate (FPC) augmented iron in Phase B. In Phase C, an FPC protocol and weekly, individualized ESA management were used. We examined clinic-level mean differences in hemoglobin (Hb) and ESRD-related outcomes by phase with repeated ANOVA. To examine the Hb at the patient level, we used multi-level mixed-effect regression adjusting for phase, month, and other relevant confounders at each month over time to derive the mean marginal effects of phase. There were 54, 78, and 66 patients in phases A, B, and C, respectively, with raw mean Hb values of 9.9, 10.2, and 10.3 g/dL. The percentage of Hb values < 9 g/dL declined from 14.3% in Phase A to 7.6% in Phase C (p = 0.007). The multivariable mixed-effect regression results showed mean marginal Hb was higher by 0.3 mg/dL and 0.4 mg/dL in Phases B and C, respectively, compared to Phase A. We also observed reduced ferritin (p = 0.003) and transferrin saturation (TSAT) (p = 0.008) levels from Phase A to Phase C with the repeated ANOVA analysis. Ferric pyrophosphate citrate (FPC) appears to support more efficient ESA-stimulated erythropoiesis. Moreover, individualized ESA management combined with FPC (Phase C) was associated with further improvement in efficiency as we observed the fewest patients with Hb values < 9 g/dL concurrent with greater decreases in ferritin levels and reduced ESA doses. However, future prospective studies to confirm these findings on a larger, more diverse cohort of ESRD patients are warranted.