[Evolution of the darbepoetin alpha resistance index in patients on dialysis who change from weekly to fortnightly treatments in clinical practice]. / Evolución del índice de resistencia a darbepoetina alfa en pacientes dializados que cambian de administración semanal a quincenal en la práctica clínica.

BACKGROUND: Darbepoetin alpha (DA) administered every-other-week (Q2W) is efficacious and safe for the treatment of anaemia in patients undergoing dialysis. There are no data available regarding the evolution of erythropoietic resistance index (ERI) after conversion from weekly (QW) to Q2W administration of DA in clinical practice. MATERIAL AND METHODS: Multicenter, observational, retrospective, 16-weeks study, which included stable patients undergoing dialysis who were converted from DA QW to DA Q2W in clinical practice. Conversion was done according to product specifications (duplicating QW dose). The ERI to DA was calculated by dividing the weekly DA dose per kilogram of weight (microg/wk.kg)*200 by the Hb level (g/dL). ERI evolution with time was evaluated by multivariate repeated measures ANOVA, adjusting for significant covariates. RESULTS: A total of 202 patients were included (137 patients undergoing haemodialysis [HD], intravenous (IV) DA, and 65 patients receiving peritoneal dialysis [PD], subcutaneous DA). Mean (SD) age was 66 (17) years; 61% of patients were men. Large intercentre variability was observed for the ERI at conversion time (coefficient of variation of 88%, p < 0.001 for differences between centres). In the univariate analysis, predictor factors for high baseline ERI were low albumin level (r = -0.29; p =0.001), HD (mean ERI of 9.3 [8.4] vs 6.8 [4.6] for PD; p = 0.005), or previous cardiovascular disease (9.9 [8.7] vs 7.4 [6.3] for patients without history; p =0.025). During the follow up, the ERI was slightly increased in HD patients (9.3 [8.4] at conversion vs 11.1 [7.3] at 16 weeks; p < 0.05), and remained stable in PD patients (6.8 [4.6] vs 6.7 [4.0], respectively; NS). In the multivariate analysis, there were no significant differences in ERI during the 16 weeks post-conversion after adjusting for albumin levels and centre (adjusted baseline mean [95% CI] of 10.0 [8.7-11.4] vs 10.5 [9.3-11.8] at 16 weeks, adjusted change of +0.5 [-0.67; 1.67]; NS). After 16 weeks, only 7 patients (3.5%) had discontinued Q2W administration. CONCLUSIONS: Extension from weekly to once every other-week darbepoetin alpha allows to simplify anaemia treatment without increasing the resistance index, regardless of dialysis type. The multivariate analysis shows that, after adjusting by center and inflammation/nutritional status, there were no changes in the response to darbepoetin alpha during the first 16 weeks after conversion in clinical practice.

The position of the peritoneal dialysis catheter is not essential for a correct performance.

The success of chronic peritoneal dialysis (PD) is a well-functioning catheter. It is recommended to place the tip of PD access in the intraabdominal deep pelvic area. The authors' objectives were to prove if the PD device should be necessarily located in the pelvic area to function properly, and if the X-ray exploration should be compulsory when blinded implantation technique is used. 42 stable patients on PD were included in the study, infusion and drainage times were recorded and an abdominal X-ray was performed at the same time. Catheter was correctly located in 25 (59.5%) cases and in 17 (40.5%) it was malpositioned. We observed that there were no differences in infusion times, but in the first group drainage was faster than in the second although not significant: infusion 10.5 vs. 10.6 minutes and drainage 14.7 vs. 15.8 minutes. These clinical observations support the fact that catheters' function would not necessarily depend on its intraabdominal position and that a radiological exploration should not be mandatory.