K. Hassani

A model to predict optimal dialysate flow.

Diffusive clearance depends on blood (Qb) and dialysate flow (Qd) rates and the overall mass transfer area coefficient (KoA) of the dialyzer. In this article we describe a model to predict an appropriated AutoFlow (AF) factor (AF factor = Ratio Qd/Qb), that is able to provide adequate Kt/V for hemodialysis patients (HDP), while consuming lower amounts of dialysate, water and energy during the treatment. We studied in vivo the effects of three various Qd on the delivered dose of dialysis in 33 stable HDP. Hemodialysis was performed at Qd of 700 mL/mn, 500 mL/mn, and with AF, whereas specific dialysis prescriptions (treatment time, blood flow rate [Qb], and type and size of dialyzer) were kept constant. The results showed that increasing the dialysate flow rate more than the model of AF predicted had a small effect on the delivered dose of dialysis. The Kt/V (mean ± SD) was 1.52 ± 0.16 at Qd 700, 1.50 ± 0.16 at Qd 500, and 1.49 ± 0.15 with AF. The use of the AF function leads to a significant saving of dialysate fluid. The model predicts the appropriate AF factor that automatically adjusts the dialysate flow rate according to the effective blood flow rate of the patient to achieve an appreciable increase in dialysis dose at the lowest additional cost.

Quantification of hemodialysis dose: what Kt/V to choose?

Background Quantification of hemodialysis became more accurate and easier after the advent of ionic dialysance and the use of methods for estimating urea distribution volume (V). The aim of this study was to compare different methods of hemodialysis dose assessment: Kt/VDau (Daugirdas 2nd generation), Kt/VOCM (Kt by OCM (Online Clearance Monitor) and V by Watson), and Kt/VBCM (Kt by OCM and V by bio-impedance); and to assess the dialysis adequacy, defined by a Kt/V≥1.4. Design Prospective, observational study. Methods 35 hemodialysis sessions were evaluated in 35 chronic hemodialysis patients. During each session, we measured simultaneously, Kt/VOCM, Kt/VBCM and calculated Kt/VDau by performing blood samples before and after each session. Results 35 patients, gender (M/F: 19/16), mean age of 50.49 years, were evaluated. We noted a difference between the three methods of evaluating Kt/V index: Kt/VDau, Kt/VOCM and Kt/VBCM (1.82 ± 0.29; 1.45 ± 0.23; 1.8 ± 0.33, p<0.001). Comparison of Kt/VOCM with Kt/VDau and Kt/VBCM leads to a significant systematic underestimate of Kt/V by 22% and 20.5% respectively. Better agreement between Kt/VDau and Kt/VBCM was observed. The adequate hemodialysis was achieved, according to three methods: Kt/VDau, Kt/VOCM and Kt/VBCM respectively in 100%, 57,1% and 88.6% of the cases. Conclusions The Kt/V index is different depending on the method used for its evaluation. The three methods can be used for quantification of hemodialysis with a better agreement between Kt/VDau and Kt/VBCM. In this study, Kt/VOCM results underestimate hemodialysis efficiency. This difference has to be considered when applying quantification of hemodialysis to clinical practice.

The Kt/V by ionic dialysance: Interpretation limits.

The availability of hemodialysis machines equipped with online clearance monitoring (OCM) allows frequent assessment of dialysis efficiency and adequacy without the need for blood samples. Accurate estimation of the urea distribution volume (V) is required for Kt/V calculated from OCM to be consistent with conventional blood sample-based methods. A total of 35 patients were studied. Ionic dialysance was measured by conductivity monitoring. The second-generation Daugirdas formula was used to calculate the Kt/V single-pool (Kt/VD). Values of V to allow comparison between OCM and blood-based Kt/V were determined using Watson formula (VWa), bioimpedance spectroscopy (Vimp), and blood-based kinetic data (Vukm). Comparison of Kt/Vw ocm calculated by the ionic dialysance and Vw (Kt/Vw ocm) with Kt/VD shows that using VW leads to significant systematic underestimation of dialysis dose by 24%. Better agreement between Kt/V ocm and Kt/VD was observed when using Vimp and Vukm. Bio-impedancemetry and the indirect method using the second-generation Daugirdas equation are two methods of clinical interest for estimating V to ensure greater agreement between OCM and blood-based Kt/V.

Gastrointestinal bleeding due to angiodysplasia in patients on hemodialysis: A single-center study.

Gastrointestinal (GI) bleeding due to angiodysplastic lesions is a common problem among patients receiving hemodialysis (HD). We studied 22 HD patients (5 females and 17 males) who had GI bleeding due to angiodysplasia; the mean age of whom was 54 ± 10 years. All patients had upper and lower GI endoscopy. The most common site for the lesion was the right colon in seven cases (31.8%), followed by stomach in 4 cases (18.1%). In eight (36.3%) patients, there were multiple lesions located in the stomach, duodenum, and the right colon. All patients were treated with coagulation; with argon plasma in 14 (63.6%) patients, bipolar coagulation in five (22.7%) patients, and hot clip in three (13.6%) patients. One patient who presented with persistent bleeding despite endoscopic therapy was well-benefited of a complementary treatment, thalidomide. Hemostasis was obtained in all patients after an average of 6.8 sessions of endoscopic coagulation procedure. We conclude that angiodysplasia is a frequent cause of hemorrhage in chronic renal failure that can be managed in most patients by argon plasma and bipolar coagulation.

[Predilution online hemodiafiltration: which dose of anticoagulation?].

INTRODUCTION Patients in end stage renal disease on hemodialysis are in higher risk of bleeding related to the anticoagulation used during a session, so only the lowest effective dose of anticoagulation must be used. The aim of this study was to evaluate the efficacy of predilution in hemodiafiltration with reduced dose of anticoagulation compared to hemodialysis in preventing coagulation of circuits. PATIENTS AND METHODS This study was conducted in stable hemodialysis patients without high bleeding risk. All patients were treated by two different treatments: (A) conventional hemodialysis, (B) predilution hemodiafiltration with the half dose of anticoagulation used during treatment (A). Other confounding parameters were kept constant during the study. The primary endpoint was the incidence of major thrombotic events judged on a subjective visual score. RESULTS Twenty-one patients were included (105 sessions for each treatment). Major incidents are occurring more frequently in predilution hemodiafiltration with reduced dose of anticoagulation (P=0.03). The premature discontinuation of sessions was more frequent in predilution hemodiafiltration, this difference was not significant (P=0.07). Duration of sessions was significantly shorter in predilution hemodiafiltration (P=0.03). The higher frequency of thrombotic events in predilution hemodiafiltration has no effect on net ultrafiltration volume achieved in both treatments. CONCLUSION Predilution hemodiafiltration with a lower dose of anticoagulation did not prevent major clotting of extracorporeal circuit manner at least equivalent to a reference method.

Insuffisance rénale aiguë révélant une hypothyroïdie auto-immune

Although the clinic picture is often indicative of muscle manifestations in patients with hypothyroidism, signs and symptoms of this condition are variable from simple elevation of serum muscle enzymes with myalgia, muscle weakness, cramps to rhabdomyolysis with acute renal failure which remains a rare event. Thyroid hormones affect the function of almost every body organ, and thyroid dysfunction produces a wide range of metabolic disturbances. Hypothyroidism is associated with significant effects on the kidney which the pathophysiology seems to be multifactorial, but the exact mechanisms remain poorly understood. Hypothyroidism as a cause of renal impairment is usually overlooked, leading to unnecessary diagnostic procedures. The main objective of our observation is to report a case of acute renal failure revealing an autoimmune hypothyroidism in which thyroid hormone substitution led to a significant improvement in muscular, thyroid and renal disorders.

Glomérulonéphrite extra-membraneuse et syndrome myélodysplasique: une association rare

Myelodysplastic syndromes may be associated with autoimmune diseases. Renal involvement is rare but, if occurs, it manifests predominantly as glomerular diseases. Extramembranous glomerulonephritis associated with myelodysplastic syndrome has been reported very rarely. We here report the case of a patient presenting with glomerulonephritis associated with anemia, revealing low-risk myelodysplastic syndrome. In the light of this case, we conducted a review of the literature of previously published cases and discussed the pathogenic link between these two entities.Les syndromes myélodysplasiques peuvent s’accompagner de maladies auto-immunes. L’atteinte rénale au cours de ces syndromes est rare. Dans ce cas, les glomérulopathies prédominent cette atteinte. La glomérulonéphrite extra-membraneuse est exceptionnellement reportée en association avec un syndrome myélodysplasique. Nous rapportons dans ce papier le cas d’une patiente présentant une glomérulonéphrite associée à une anémie révélant un syndrome myélodysplasique de faible risque. Dans la lumière de ce cas, nous faisons une courte revue de la littérature des cas précédemment publiés et nous discutons le lien pathogénique entre ces deux entités.

Complete remission of nephrotic syndrome secondary to amyloid a amyloidosis in patient with inactive Crohn's disease after treatment by infliximab

Secondary amyloidosis Amyloid A (AA) is an infrequent but a severe complication of Crohns disease (CD). This complication results from the activity of the underlying inflammation disease to form amyloid fibril deposits in tissues. We present a case of a 34-year-old female patient with CD treated by azathioprine with inactive disease for three years and who developed a nephrotic syndrome secondary to AA amyloidosis. The treatment by infliximab for one year leads to a complete remission of the nephrotic syndrome. In this case, this complication occurred while the patient was clinically well, with biological and endoscopic markers showing an inactive or only mildly active disease. Infliximab could be a useful tool for a successful treatment of amyloidosis secondary to CD.

Late-onset choreoathetotic syndrome following heart surgery in adults with end-stage renal disease

Choreoathetotic syndrome is a rare complication of open cardiac surgery that is seen usually in children after surgery for congenital cardiac anomalies. Here, we report two cases of adult patients with end-stage renal disease (ESRD) on regular hemodialysis who developed acute choreoathetotic syndrome few days after cardiac surgeries under cardiopulmonary bypass (CPB). Improvement was seen after an interval with complete resolution in one case. Investigations of the cause have been noncontributory. Long CPB time seems to be the main identified risk factor in these cases. One of the unusual features of our adult cases was the existence of ESRD. To the best of our knowledge, this is the first time this complication is described in association with ESRD although the role of this comorbidity in these cases is uncertain.

A model to calculate cardiac output in hemodialysis patients by thermodilution.

The Blood Temperature Monitor module (BTM) is used to measure recirculation by thermodilution in dialysis. Numerous studies have confirmed its interest in the measuring of the vascular access flow. In this letter we describe a model to calculate cardiac output in dialysis by the BTM.