OBJECTIVE - To determine if the simultaneous initiation of continuous ambulatory peritoneal dialysis (CAPD) and Erythropoietin therapy masks the hematocrit (Hct) rise that frequently follows the initiation of CAPD alone.
DESIGN - Single-center retrospective analysis.
SETTING - University multidisciplinary dialysis program.
PATIENTS - All adult CAPD patients with a Hct less than or equal to 28% whose nephrologist felt they would benefit from Erythropoietin therapy and who did not have technical reasons for exclusion (N = 25).
INTERVENTIONS - Eight patients began CAPD and Erythropoietin alfa subcutaneously, at a dose of 128 +/- 9 (X +/- SEM) units/kg/week at the same time. Seventeen patients already on CAPD for 8.7 +/- 1.5 months received Erythropoietin alfa subcutaneously at a dose of 124 +/- 7 units/kg/week. Pre-epoetin Hct's were similar.
MAIN OUTCOME MEASURES - Hematocrit changes, status of iron stores, incidence of peritonitis, and dosage of Erythropoietin.
RESULTS - In 1 month, the group initiating both therapies simultaneously demonstrated a mean Hct rise of 7.6 +/- 0.5% while established CAPD patients receiving Erythropoietin increased their Hct by only 4.7 +/- 1.0% (p less than .03). Iron status could not explain this difference. Peritonitis did not appear to dampen the Hct rise following Erythropoietin in either CAPD group. By 2 months after Erythropoietin, the differences were less apparent.
CONCLUSION - The early rapid increase in Hct is probably the combined effect of CAPD and Erythropoietin and should not be attributed to Erythropoietin alone. When comparing responses to Erythropoietin from patients on different therapies, the timing of dialysis initiation and Erythropoietin initiation must be considered.