Normalization of hematocrit in patients with end-stage renal disease on continuous ambulatory peritoneal dialysis: the role of erythropoietin.

Observations were made retrospectively and prospectively over one year on all patients on continuous ambulatory peritoneal dialysis (CAPD) to determine the effect of this modality on the hematocrit. Serum erythropoietin and parathyroid hormone levels were measured. Within five months the hematocrit increased 47 to 127 percent up to normal in four of nine patients. Five others remained severely anemic. There was no significant difference in serum creatinine levels among the patients within one month of CAPD. The four patients who responded were anemic while on hemodialysis and other modalities of end-stage renal disease management prior to CAPD. The serum erythropoietin level in the four patients who responded was 9.0 mU/ml or greater with a mean of 28 mU/ml, whereas in those who did not respond it was 5.0 mU/ml or less with a mean of 3 mU/ml. Since uremic toxins in the middle molecule range have been postulated to be responsible for erythropoiesis suppression in end-stage renal disease, and in addition, insufficient erythropoietin production and the clearance of some middle molecular weight substances is six times greater with CAPD than with hemodialysis, it appears that CAPD can normalize the hematocrit in patients with end-stage renal disease who were anemic on other modalities with little or no change in serum creatinine, provided the remnant kidneys are capable of producing sufficient erythropoietin. Parathyroid hormone levels were higher in patients who responded than in patients who did not respond.