Reality check: primary vascular access creation today.

INTRODUCTION: In Switzerland, the outcome of vascular access creation in the 4500 current dialysis patients is unknown, mainly because there is no prospective registry for patients undergoing vascular access surgery for renal replacement therapy. The aim of the study was to assess the quality of vascular access creation and to compare it with the current literature and guidelines, in order to define strategies to improve clinical outcome. METHODS: Retrospective single-centre study in a tertiary referral centre. All consecutive patients over 18 years of age undergoing primary vascular access creation between January 2013 and December 2014 were included. Follow-up data for at least 12 months were collected. RESULTS: During the study period, 365 patients had a surgical intervention for renal replacement therapy. A primary vascular access was created in 74 patients (20%), who were further analysed in our study: 63 (85%) had an arteriovenous fistula (AVF) and 11 (15%) an arteriovenous graft (AVG). The intervention-free survival (primary patency rate) of the primary vascular access at 1 year was 46% (95% confidence interval [CI] 33-58%) for AVF and 30% (95% CI 7-58%) for AVG, with a secondary patency rate at 1 year of 75% (95% CI 63-84%) for AVF and 50% (95% CI 18-75%) for AVG. Twenty-seven patients (36%) with primary vascular access underwent central venous catheter (CVC) placement (tunnelled or non-tunnelled) before the access creation. Thirty-seven (50%) patients had their first dialysis through a CVC. Thirty-one patients (42%) never received a CVC. CONCLUSIONS: The primary patency of vascular access was unexpectedly low, and the number of CVC requests unexpectedly high. In light of this, we consider it essential that centres creating vascular access should register their activities and compare their outcomes with current guidelines to check and improve clinical management. To facilitate this, there is an initiative starting in 2018 encouraging all Swiss vascular surgeons to provide data on vascular access interventions, including 1-year follow-up, in the national online registry "SwissVasc 2.0".

Clinical Validation of a Peritoneal Dialysis Prescription Model in the PatientOnLine Software.

Peritoneal transport characteristics and residual renal function require regular control and subsequent adjustment of the peritoneal dialysis (PD) prescription. Prescription models shall facilitate the prediction of the outcome of such adaptations for a given patient. In the present study, the prescription model implemented in the PatientOnLine software was validated in patients requiring a prescription change. This multicenter, international prospective cohort study with the aim to validate a PD prescription model included patients treated with continuous ambulatory peritoneal dialysis. Patients were examined with the peritoneal function test (PFT) to determine the outcome of their current prescription and the necessity for a prescription change. For these patients, a new prescription was modeled using the PatientOnLine software (Fresenius Medical Care, Bad Homburg, Germany). Two to four weeks after implementation of the new PD regimen, a second PFT was performed. The validation of the prescription model included 54 patients. Predicted and measured peritoneal Kt/V were 1.52 ± 0.31 and 1.66 ± 0.35, and total (peritoneal + renal) Kt/V values were 1.96 ± 0.48 and 2.06 ± 0.44, respectively. Predicted and measured peritoneal creatinine clearances were 42.9 ± 8.6 and 43.0 ± 8.8 L/1.73 m(2)/week and total creatinine clearances were 65.3 ± 26.0 and 63.3 ± 21.8 L/1.73 m(2) /week, respectively. The analysis revealed a Pearson's correlation coefficient for peritoneal Kt/V of 0.911 and Lin's concordance coefficient of 0.829. The value of both coefficients was 0.853 for peritoneal creatinine clearance. Predicted and measured daily net ultrafiltration was 0.77 ± 0.49 and 1.16 ± 0.63 L/24 h, respectively. Pearson's correlation and Lin's concordance coefficient were 0.518 and 0.402, respectively. Predicted and measured peritoneal glucose absorption was 125.8 ± 38.8 and 79.9 ± 30.7 g/24 h, respectively, and Pearson's correlation and Lin's concordance coefficient were 0.914 and 0.477, respectively. With good predictability of peritoneal Kt/V and creatinine clearance, the present model provides support for individual dialysis prescription in clinical practice. Peritoneal glucose absorption and ultrafiltration are less predictable and are likely to be influenced by additional clinical factors to be taken into consideration.

[Renal replacement therapies ­ Past, present and future]. / Nierenersatzverfahren - gestern, heute und morgen.

Extracorporeal renal replacement therapy is one of the most successful stories of artificial organ replacement. The current article describes the important steps in the evolution of renal replacement therapy towards modern state of the art peritoneal dialysis and hemodialysis. Open questions and possibilities for future developments are discussed. Today patients have a choice with respect to the method used to replace their failing kidney. However, in order to carefully plan and select the best possible method for a patient, he has to be seen and confronted with the various methods by a nephrologist at least six month before the necessity to start renal replacement therapy. Late referral increases mortality and the necessity for a temporary central venous access represents an additional thrombotic and infectious risk. A patient first seen by the nephrologist at the occasion of an emergeny dialysis will never have the possibility to profit from a preemptive living kidney donation. Furthermore, such patients usually stay in the center and are difficult to motivate for home or selfcare dialysis.

The Validation of a New Visual Anaemia Evaluation Tool HemoHue HH1 in Patients with End-Stage Renal Disease.

In chronic haemodialysis patients, anaemia is a frequent finding associated with high therapeutic costs and further expenses resulting from serial laboratory measurements. HemoHue HH1, HemoHue Ltd, is a novel tool consisting of a visual scale for the noninvasive assessment of anaemia by matching the coloration of the conjunctiva with a calibrated hue scale. The aim of the study was to investigate the usefulness of HemoHue in estimating individual haemoglobin concentrations and binary treatment outcomes in haemodialysis patients. A prospective blinded study with 80 hemodialysis patients comparing the visual haemoglobin assessment with the standard laboratory measurement was performed. Each patient's haemoglobin concentration was estimated by seven different medical and nonmedical observers with variable degrees of clinical experience on two different occasions. The estimated population mean was close to the measured one (11.06 ± 1.67 versus 11.32 ± 1.23 g/dL, P < 0.0005). A learning effect could be detected. Relative errors in individual estimates reached, however, up to 50%. Insufficient performance in predicting binary outcomes (ROC AUC: 0.72 to 0.78) and poor interrater reliability (Kappa < 0.6) further characterised this method.

Modeling of red blood cell life-spans in hematologically normal populations.

Despite the impact of red blood cell (RBC) Life-spans in some disease areas such as diabetes or anemia of chronic kidney disease, there is no consensus on how to quantitatively best describe the process. Several models have been proposed to explain the elimination process of RBCs: random destruction process, homogeneous life-span model, or a series of 4-transit compartment model. The aim of this work was to explore the different models that have been proposed in literature, and modifications to those. The impact of choosing the right model on future outcomes prediction--in the above mentioned areas--was also investigated. Both data from indirect (clinical data) and direct life-span measurement (biotin-labeled data) methods were analyzed using non-linear mixed effects models. Analysis showed that: (1) predictions from non-steady state data will depend on the RBC model chosen; (2) the transit compartment model, which considers variation in life-span in the RBC population, better describes RBC survival data than the random destruction or homogenous life-span models; and (3) the additional incorporation of random destruction patterns, although improving the description of the RBC survival data, does not appear to provide a marked improvement when describing clinical data.

Red cell survival in relation to changes in the hematocrit: more important than you think.

The management of anemia in patients with chronic renal failure has greatly improved with the availability of recombinant human erythropoietin in the late 1980s, leading to a considerable reduction in mortality and morbidity and to an improvement in quality of life. The findings from recent controlled clinical outcome trials have resulted in a rather narrow, generally accepted therapeutic hematocrit target range. However, currently available dosing algorithms do not permit achievement and maintenance of target values within the therapeutic range in many patients. One possible explanation for this failure may be the ignorance of a finite erythrocyte lifespan not integrated into most algorithms. The purpose of this article is to underline the essential role played by the erythrocyte lifespan in the erythropoietic response to recombinant human erythropoietin and to encourage the integration of this concept in the future development of computer-assisted decision support systems.

Use of the pentasaccharide fondaparinux as an anticoagulant during haemodialysis.

No data about the use of the pentasaccharide fondaparinux, a highly selective indirect inhibitor of factor Xa, in patients treated with haemodialysis are available. Therefore, we investigated the pharmacokinetics and -dynamics of fondaparinux in 12 patients during haemodialysis. The anti-Xa activity (expressed as fondaparinux equivalent) was monitored, a semiquantitative clotting scale (SQCS) ranging from 0 (no visible traces of coagula) to 3 (complete clotting of the dialysis circuit) was applied, and the digital compression time necessary to achieve haemostasis at the puncture site was determined. After an initial period, when the regular heparin dose was replaced once weekly by fondaparinux, 0.05 mg/kg, the pentasaccharide was administered for nine consecutive haemodialysis sessions. Peak anti-Xa activity increased from 0.61 +/- 0.14 microg/l after the first dose to 0.89 +/- 0.24 microg/l after dose 9 (P < 0.001), whereas predialysis anti-Xa activity steadily rose to 0.32 +/- 0.09 microg/l (P < 0.001). A sufficient but slightly less effective anticoagulation with a mean SQCS of 1.19 +/- 0.71 (n = 121) was obtained by fondaparinux as compared with 0.65 +/- 0.58 (n = 60, P < 0.005) by 4,825 +/- 1,703 U of unfractionated heparin. Mean digital compression time rose slightly during fondaparinux from 23.7 +/- 7.4 minutes to 24.8 +/- 7.5 minutes (P < 0.05) and, more important, six of the 12 patients reported minor bleeding problems during the interdialytic interval. Thus, fondaparinux can be used to prevent circuit clotting during haemodialysis; however, accumulation results in an interdialytic increase of anti-Xa activity. Therefore, fondaparinux should be reserved for patients requiring systemic anticoagulation on the days off dialysis.