Is hematologic response to iron and erythropoietin in hemodialysis patients affected by other factors?

Multiple factors have been implicated in the hematologic response to erythropoietin (EPO). The authors studied 54 hemodialysis patients; 44 received 1.5 g of iron intravenously, 16 received oral iron for 12 weeks, and 24 were treated with EPO. Some patients received these treatments in sequence. The factors evaluated were serum albumin, protein catabolic rate, serologic evidence of hepatitis B or C, parathormone (PTH), and aluminum levels. Red cell production was expressed as milliliters of red blood cell increase per day per kilogram of body weight. For patients receiving EPO, hematologic response was normalized to 50 U/kg/dialysis. Of the patients on oral iron, 31% had a good response (hematocrit greater than or equal to 30%). Of the patients who received iron intravenously, 50% had a good response (hematocrit greater than or equal to 30%). All patients treated with EPO responded well, except for one patient who did not respond to doses of EPO up to 200 U/kg/dialysis. The response to intravenous iron dextran was more rapid than the response to oral iron or EPO. Nutritional factors (serum albumin and protein catabolic rate), serologic evidence of hepatitis, elevated PTH levels, or elevated aluminum levels did not significantly affect the response to iron supplementation or EPO treatment.

Evaluation of hemodialysis patients treated with erythropoietin.

We evaluated 20 hemodialysis patients who had been treated with erythropoietin (Epo). All patients had hemoglobin levels below 8.5 g/dL. They were randomized to receive either Epo (100 U/kg) or placebo three times per week for 12 weeks. All patients on Epo had a significant (P less than 0.001) elevation of hematocrit levels (19.7% v 35.7%). They also had a significant (P less than 0.05) increase in midweek predialysis blood urea nitrogen (BUN) levels, 27.8 versus 29.6 mmol/L (78 v 83 mg/dL), and serum phosphorus, 1.8 versus 2.1 mm/L (5.7 v 6.6 mg/dL). Protein catabolic rate also increased significantly (P less than 0.05). No changes were seen in the levels of serum creatinine and potassium, but episodes of hyperkalemia were more frequent in patients on Epo. No changes were seen in patients on placebo. When hematocrit increased, the clearance of blood-water for urea decreased 9%, and the clearance of creatinine, potassium, and phosphorus decreased 15%. Patients on Epo increased both their appetite and protein intake. More frequent episodes of hyperkalemia and elevated phosphorus level resulted from a combination of increased intake and decreased dialyzer clearance. We may need blood-water clearance to calculate Kt/V.

Are high flux dialysis and erythropoietin treatment in a collision course?

Twenty patients treated with human recombinant erythropoietin (EPO) for 9 months were studied. The patients were randomly allocated to high flux (HF) or conventional dialysis (CD). Patients on HF used the F-60 or F-80 dialyzer, with a polysulfone membrane; QB: 470 ml/min; QD: 800 ml/min; t: 127 min; Kt/V: 1.01. Conventional dialysis patients used regenerated cellulosic membranes; QB: 297 ml/min; QD: 500 ml/min; t: 193 min; Kt/V: 1.05. Mean dose of EPO was 103 U/kg for HF patients and 112.4 U/kg for patients on CD. At 9 months, no significant differences were observed in HCT (HF 33.6% vs. CD 33.2%), BUN, serum creatinine, potassium, or phosphorus. Hemoconcentration during dialysis was 12% for HF and 17% for CD. Urea clearance decreased 7% for HF and 9% for CD, while clearance of creatinine, potassium, and phosphorus decreased between 14 and 18% with both treatments. Heparin requirements increased 10% in HF and 16% in CD. Hypertension was similar in both groups. One HF patient withdrew from the study because of hypertension and one HF patient had seizures related to hypertension. Vascular access clotting or hospitalizations were no different. High flux dialysis patients on EPO over a 9 month period did not have any catastrophic complications when HCT was maintained between 30 and 35%.