Epoetin Alfa Resistance: Valuation of a Management Algorithm: METHODS
After searching MEDLINE to identify common causes of epoetin alfa resistance, the authors from the Renal Risk Reduction Centre at St Paul’s Hospital, Saskatoon, Saskatchewan, developed an algorithm to guide the investigation and management of suspected epoetin alfa resistance. After discussion with nurses and physicians in the renal unit, the algorithm was modified. The algorithm (Figure 1) was designed for use by physicians, pharmacists, and nurses involved in the management of patients on chronic dialysis.
For the purposes of the algorithm, epoetin alfa resistance was defined as the receipt of epoetin alfa doses of more than 300 IU kg-1 week-1 SC10, regardless of the hemoglobin concentration. Iron deficiency was defined as an iron saturation of less than 20% or a serum ferritin of less than 100 pg/L in the previous 3 months.2 Inadequate dialysis was defined as a Kt/Vof less than 1.4. The Kt/V is a measure of dialysis adequacy, where K is the dialyzer clearance, t is the treatment time, and V is the volume of urea. Infection and inflammation were defined as a current infectious or inflammatory disease such as active systemic lupus erythematosus, Wegener’s granulomatosis, or pericarditis. Elevated aluminum and parathyroid hormone serum concentrations were defined as concentrations greater than 2300 nmol/L and 20 pmol/L, respectively.
All patients seen in the hemodialysis clinic from October through December 2000 who had a hemoglobin concentration of less than 110 g/L for 3 consecutive months and who were taking any dose of epoetin alfa were identified. The algorithm was then used by a pharmacist and a physician to identify possible causes of anemia and to guide its management. Patient outcomes were tracked for 3 months after patients were enrolled in the study. Serum iron, totaliron-binding capacity, and percent iron saturation were determined every 3 months from the time of enrolment in the study until the study’s end in March 2001. Hemoglobin concentrations were assessed monthly, and serum vitamin B12 and folic acid concentrations were assessed in January 2001. viagra jelly
All data are presented as means standard deviation. A paired Student Mest was used to compare patient hemoglobin concentrations at baseline and at the end of the 3-month follow-up period. Statistical significance was defined as p = 0.05.