Blood and Dialysate Flow Distributions in Hollow-Fiber Hemodialyzers Analyzed by Computerized Helical Scanning Technique

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Artificial Diuresis: animal studies on efficacy and safety of a new miniaturized device for extracorporeal ultrafiltration

Introduction. We have recently developed a new miniaturized device for extracorporeal ultrafiltration to be used in patients with fluid overload: Artificial Diuresis-1, or AD1 (Medica S.p.A., Medolla, Italy). The device has a reduced priming volume and operates at very low pressure and flow regimes and is designed to perform extracorporeal UF at bedside. After accurate experiments carried out in vitro, we report in this paper the results of in vivo tests ultrafiltration session carried out in selected animals according to veterinary best practice. Materials and methods. The AD1 kit is pre-filled with sterile isotonic solution and operates with a polysulfone mini-filter MediSulfone (Polysulfone at 50000 Dalton). A collection bag with a volumetric scale is connected to the UF line and the ultrafiltrate is obtained by gravity based on the height at which the ultrafiltrate collection bag is placed. Animals were prepared and anesthetized. Jugular vein was cannulated with a double lumen catheter. Three six hours sessions of ultrafiltration were scheduled with a target fluid removal of 1500 ml. Heparin was used as anticoagulant.Results. In all treatments the target value of ultrafiltration was obtained in the absence of major clinical or technical problems with a maximum deviation from the scheduled ultrafiltration rate lower than 10%. The device resulted safe, reliable, accurate and easily usable thanks to a user friendly interface and the very small dimensions. Conclusions. This study opens the way for clinical trials in different settings including departments with low intensity of care and even in ambulatory centers or patient's home

Erythropoeitin dose variation in different facilities in different countries and its relationship to drug resistance Management of comorbidities in kidney disease in the 21st century: Anemia and bone disease

Erythropoeitin dose variation in different facilities in different countries and its relationship to drug resistance.BackgroundThe correction of anemia using erythropoeitin (EPO) is accorded high priority in the management of patients undergoing hemodialysis (HD). Target hemoglobin (Hb) levels have been established in many countries. Following an observation that the mean facility EPO dose in a chain of facilities in the United States varied by more than two-fold, an examination of the practice of anemia correction in other settings was carried out.MethodsWe reviewed demographic and laboratory parameters in prevalent HD patients in 50 United States facilities and in a single HD facility in Vicenza, Italy. The mean EPO dose profile of the United States facilities was compared with the profiles in 10 facilities in the eastern United Kingdom (UKER) and in 20 facilities reporting to the United Kingdom Renal Registry (UKRR). Analysis of the factors that correlate with EPO resistance was carried out using the United States and Italian data.ResultsThe average EPO doses, by facility, in the 51 United States, the 10 UKER, and the 19 UKRR facilities were 19,569, 8,416, and 7,992 international units per week (IU/wk), respectively. While examination of the UKRR revealed a similar degree of inter-facility variation (2.6-fold), much larger doses of EPO were being administered in the United States patients, particularly in the low Hb group. Multivariate analysis of the United States data suggested that factors related to inflammation, including low albumin, the use of tunneled catheters for vascular access, and low protein catabolic rate (enPCR) correlated with low Hb and relative EPO resistance.ConclusionDespite similar guidelines for anemia management, significant differences in practice are observed. While there seems to be a reluctance to administer large EPO doses to individual patients in Europe, this does not seem to apply in the United States, where more EPO is given. EPO resistance seems relative rather than absolute in many patients, allowing some to respond to the higher doses

Study protocol: The DOse REsponse Multicentre International collaborative initiative (DO-RE-MI)

INTRODUCTION: Current practices for renal replacement therapy in intensive care units (ICUs) remain poorly defined. The DOse REsponse Multicentre International collaborative initiative (DO-RE-MI) will address the issue of how the different modes of renal replacement therapy are currently chosen and performed. Here, we describe the study protocol, which was approved by the Scientific and Steering Committees. METHODS: DO-RE-MI is an observational, multicentre study conducted in ICUs. The primary end-point will be the delivered dose of dialysis, which will be compared with ICU mortality, 28-day mortality, hospital mortality, ICU length of stay and number of days of mechanical ventilation. The secondary end-point will be the haemodynamic response to renal replacement therapy, expressed as percentage reduction in noradrenaline (norepinephrine) requirement. Based on the the sample analysis calculation, at least 162 patients must be recruited. Anonymized patient data will be entered online in electronic case report forms and uploaded to an internet website. Each participating centre will have 2 months to become acquainted with the electronic case report forms. After this period official recruitment will begin. Patient data belong to the respective centre, which may use the database for its own needs. However, all centres have agreed to participate in a joint effort to achieve the sample size needed for statistical analysis. CONCLUSION: The study will hopefully help to collect useful information on the current practice of renal replacement therapy in ICUs. It will also provide a centre-based collection of data that will be useful for monitoring all aspects of extracorporeal support, such as incidence, frequency, and duration

Effects of fluid overload on heart rate variability in chronic kidney disease patients on hemodialysis

BACKGROUND: While fluid overload (FO) and alterations in the autonomic nervous system (ANS) such as hypersympathetic activity, are known risk factors for cardiovascular morbidity and mortality in patients on chronic hemodialysis (HD), their relationship has not been thoroughly studied. METHODS: In this observational study involving 69 patients on chronic HD, FO was assessed by whole body bioimpedance measurements before the midweek HD session and ANS activity reflected by Heart Rate Variability (HRV) was measured using 24-hour Holter electrocardiogram recordings starting before the same HD treatment. In total, 13 different HRV indices were analyzed, comprising a mixture of time domain, frequency domain and complexity parameters. A correlation analysis was performed between the HRV indices and hydration status indices. Successively, patients were retrospectively assigned to a high FO (H, FO > 2.5 L) or low FO (L, FO ≤ 2.5 L) group and these were further compared also after stratification by diabetes mellitus. Finally, a small number of patients without diabetes with significant and persistent FO were followed up for 3 months post-study to investigate how normalization of fluid status affects HRV. RESULTS: SDANN, VLF, LZC and HF% parameters significantly correlate with FO (correlation coefficients were respectively r = –0.40, r = –0.37, r = –0.28 and r = 0.26, p-value < 0.05). Furthermore, LF% and LF/HF were inversely correlated with hydration status (correlation coefficients were respectively r = –0.31 and r = -0.33, p-value < 0.05). These results indicate an association between FO and reduced HRV, higher parasympathetic activation and reduced sympathetic response to the HD session. Indeed, group H tended to have lower values of SDANN, VLF and LZC, and higher values of HF% than patients in the L group. Finally, there was a trend towards lower LF% measured during the last 30 minutes of HD for the H group versus the L group. Reduction in FO achieved over 3 months by implementation of a strict fluid management plan resulted in an increase of HRV. CONCLUSIONS: Our results suggest that depressed HRV is associated with fluid overload and that normalization of hydration status is accompanied by improved HRV