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.