Comparison of the therapeutic efficacy of epoetin beta and epoetin alfa in maintenance phase hemodialysis patients.

In May 2009 for financial reasons, the epoetin product used for hemoglobin (Hb) maintenance in our renal dialysis unit was changed from epoetin beta to epoetin alfa. Although widely believed that the dosage requirements are the same, we undertook a retrospective analysis to investigate whether the dosage requirements in chronic renal failure patients were comparable for both preparations. We studied 128 stable end-stage renal failure patients on hemodialysis (three times per week) receiving erythropoietin therapy to maintain their Hb at 11-12.5 g/dL. Patients were excluded if within the study period they developed signs of infection, bleeding, required blood transfusion, were under-dialyzed, or required hospital admission. Regular monthly Hb concentrations and hematocrit (Hct) levels were measured for each patient. The weekly EPO index (defined as weekly epoetin dose/mean monthly Hct) was derived for each patient, before and after regime change. Of the 128 patients in end-stage renal failure, 79 were included in the study. There was no significant difference between the two preparations in terms of Hct level achieved (p = 0.15). However, the median weekly epoetin dose requirement increased from 6733 (range 750-30,000) IU/week to 9000 (250-30,667) IU/week (p < 0.001). EPO index similarly increased from 20,465 (2500-130,846) IU/week/% to 27,073 (729-98,937) IU/week/% (p < 0.001). Our study showed that a higher dose of epoetin alfa was needed to maintain target Hb concentration.

Volume blood flow, static pressure ratio and venous conductance in native arterio-venous fistulae: three surveillance methods compared.

PURPOSE: Dialysis venous pressure monitoring has been widely recommended as a surveillance method but has not been shown to improve access outcomes in randomised controlled trials. The method has been impaired by the need to either turn off the blood pump or to derive the static venous pressure from the venous pressure measured with the dialysis pump running. We have developed a unique algorithm which converts Doppler-shifted spectral information derived from unscaled pulsatile blood flow waveforms into an estimate of mean blood pressure (MBP) at the point of ultrasound insonation. METHODS: We have devised the unique expression shown here: MBP = MAP/(1 + Pff/Vff) where MAP is the mean arterial pressure, Pff = (systolic - diastolic)/MAP measured on the contralateral arm and Vff = spectral maximum - minimum/mean. Venous conductance (VC) can be measured by combining this pressure data with Duplex ultrasound blood flow data. A new device BlueDop™ has been used to illustrate the potential clinical value of non-invasive static pressure ratio (SPRn) in a monitoring role. Duplex and BlueDop™ technology were tested in an arterio-venous fistula (AVF) study in which VC, Q and SPRn were compared. Thresholds used for detection of ≥60% venous stenosis were VC <10 mL min-1 mm Hg-1, Q <500 mL min-1, SPRn >0.56. RESULTS: The following accuracy was achieved: VC = 96%, Q = 92%, SPRn = 76% with similar accuracy in predicting premature thrombosis. CONCLUSIONS: A new algorithm has been described and its in vivo accuracy in estimating mean 'pressure from flow' has been confirmed. Two new variables and a new dedicated instrument BlueDop™ have been demonstrated in clinical use.

The development of focal segmental glomerulosclerosis secondary to anabolic steroid abuse.

The authors present the case of a patient who presented to the nephrology department of a district general hospital with end-stage renal failure. He presented with malignant hypertension and symptoms and signs of uraemia. He also gave a history of prior abuse of anabolic steroids over a number of years. Renal biopsy was performed and the findings were in keeping with a diagnosis of advanced focal segmental glomerulosclerosis (FSGS). The patient went on to require renal replacement therapy within weeks of presentation. The authors suggest that anabolic steroid abuse is a direct cause of FSGS. People with raised body mass index are known to be at increased risk of developing this condition, due to increased haemodynamic stress on the glomeruli, with subsequent development of sclerosis. However, the authors believe that anabolic steroid abuse may be an independent risk factor, and that anabolic steroids have a direct nephrotoxic effect that leads to a more advanced initial presentation with rapid decline in renal function.