Relationship between Anemia and Adequacy of Continuous Ambulatory Peritoneal Dialysis

Sylvie Opatrná, MD, 1st Department of Internal Medicine, Charles University, Alej Svobody 80, CS-304 60 Plzen (Czech Republic), Tel. +42 19 522564, fax +42 19 531110 Dear Sir, It is generally recognized that anemia is a common symptom of chronic renal failure which causes a number of serious problems to the patient. Some studies claim that, in hemodialysis patients, success in treating anemia depends on the efficacy of dialysis therapy. The importance of adequate hemodialysis for successful control of anemia has recently received authoritative support especially by a study conducted by Ifudu et al. [1]· Regarding the relationship between anemia and efficacy of continuous ambulatory peritoneal dialysis (CAPD), it has been explored to a much lesser extent than was the case for hemodialysis, and, what is more, the results are controversial. While some studies have not demonstrated an association, other authors have, even though in case reports [2-4]. Because of the paucity of unambiguous information, we conducted a study designed to establish whether or not the renal anemia in patients with chronic renal failure is affected by the adequacy of CAPD. We examined 22 patients with a mean age of 51.8 (20-79) years (arithmetic mean and range) treated by CAPD (Twin-Bag System; Baxter, Deerfield, Ill., USA) for 14.8 (1.5-52) months for chronic renal failure caused by chronic tubulointerstitial nephritis in 8 cases, chronic glomerulonephritis in 7, diabetic nephropathy in 5, polycystic kidney disease in 1 ‚ and Fanconi’s syndrome in 1 case. None of the patients received recom-binant human erythropoietin or blood transfusion for renal anemia. At the same time the hematocrit was 30.9% (19.4-43.3). The KT/ V index had not changed for 6.3 (1.5-24) months prior to the study when it was at 2.0 (1.4-2.8) per week. The residual glomerular filtration rate (GFR) was 4.8 (0-9.4) ml/ min. The efficacy of blood purification was assessed by the KT/V index considering both peritoneal and renal urea clearances [KT/ Vurea = (Durea/Purea·VD + Curea)/Vtot] and by weekly creatinine clearance corrected for body surface area (BSA), again considering both peritoneal and renal eliminations (Ccrea/BSA = Dcrea/Pcrea·VD·7 + GFRest). The residual GFR was determined as the arithmetic mean of urea and creatinine clearances [GFRest = (Curea + Ccrea)/2] [5]. Besides the hematocrit, we examined, using standard methods,