The effect of hematocrit on peritoneal transport

Eight stable patients, from our institution, on continuous ambulatory peritoneal dialysis (CAPD) were entered into a multicenter, randomized, double-blind, placebo-controlled study with erythropoietin (EP]. To assess the effect of hematocrit on peritoneal solute transport, we performed peritoneal equilibration tests (PET) on each patient on a quarterly basis throughout the study. Patients on EPO had a significant increase in hematocrit at 3 (32% +/- 5%), 6 (32% +/- 2%), and 9 (38% +/- 3%) months compared with baseline (22% +/- 4%). The D/P creatinine (Cr) at 4 hours was also significantly reduced in the patients on EPO at 3 (.70 +/- .1), 6 (.66 +/- .12) months when compared with baseline (.76 +/- .11). No significant change in D/Do glucose at 4 hours or in the 4-hour ultrafiltrate (except at 9 months) was found. Based on mixed-effects regression analysis, the 4-hour D/P Cr, peritoneal Cr clearance, and Cr mass transfer area coefficient significantly decreased as hematocrit levels increased. The 4-hour D/Do glucose and the 4-hour ultrafiltrate both demonstrated a positive correlation with increasing hematocrit levels, but this did not reach statistical significance. Although larger studies are needed, it appears that increasing hematocrit levels may negatively affect peritoneal solute transport in CAPD patients as determined by PET.