[Frequency of thrombosis in hemodialysis arteriovenous fistulas. Contribution of 2 surveillance methods: Doppler and dilution ultrasound techniques]. / Fréquence des thromboses des fistules artério-veineuses pour hémodialyse: apport de deux méthodes de surveillance: le Doppler et la dilution des ultrasons.

A correct access flow is one of the most important factors for dialysis efficiency. Clinical examination does not allow the detection of flow decrease. We conducted a prospective study comparing the dilution ultrasound system (Transonic) to duplex Doppler sonography (GE logiq 700 expert series) in two phases: Comparison of the access flow values obtained with both devices and discussion of their discrepancies. Scheduled survey of vascular access, analysis of its results regarding the rate of fistula thrombosis, then definition and achievement of a strategy of early preventive surgery. After two years, flow data were similar with both systems, provided that Transonic values were corrected by a constant coefficient. The use of both techniques during the scheduled survey of fistulas resulted in a 43% decrease of the rate of acute thrombosis (p < 0.05).

[Neurologic toxicity caused by zelitrex (valaciclovir) in 3 patients with renal failure. Is overdose associated with improvement of product bioavailability improvement?]. / Toxicité neurologique induite par le Zelitrex (valaciclovir) chez trois patients insuffisants rénaux. Surdosage lié à l'amélioration de la biodisponibilité du produit?

INTRODUCTION: We report three cases of neurotoxicity in patients with renal failure, treated with Zelitrex (valacyclovir). EXEGESIS: The patients are two women and a man, aged 76 +/- 4.6 years, who presented acute mental confusion during a treatment with valacyclovir. In two cases, the patients previously had altered renal function and were under peritoneal dialysis. In the last case, the patient had simultaneous neurotoxicity and acute renal failure. After the discontinuation of the drug, the outcome was favourable in all cases. CONCLUSION: Our cases focus attention on the possible neurotoxicity of valacyclovir, which is an amino acid ester prodrug of acyclovir, rapidly and almost completely hydrolysed to acyclovir prior to systemic exposure. The bioavailability of valacyclovir is 54% compared to approximately 20% for oral acyclovir and may account for unexpected overdoses, which may lead to serious neurological toxicity.

Tissue factor coagulation pathway and blood cells activation state in renal insufficiency.

INTRODUCTION: Atherosclerotic cardiovascular disease is the leading cause of the increased morbidity and mortality observed in uremic patients. Thrombosis is an important contributor to the evolution of atherosclerotic lesions. The physiologically-relevant blood clotting depends on binding of activated factor VII (FVIIa) to exposed tissue factor (TF) on activated/damaged cells. MATERIALS AND METHODS: A cross-sectional study was performed on three age- and sex-matched groups of individuals: one group of 50 patients on maintenance hemodialysis (D group), one of 50 patients with a non-dialysed renal insufficiency (ND group) and one of 50 healthy controls (HC group). We studied basal plasma concentrations of FVIIa, factor VII-related antigen (FVIIAg), soluble TF, tissue factor pathway inhibitor (TFPI), TF-dependent circulating monocytes procoagulant activity (TF-dMPA), tissue factor-dependent plasma reactivity to activated protein C (TF-aPC), D-dimers (D-Di), and circulating markers of cellular activation/injury: soluble thrombomodulin (sTM), circulating microparticles (microP), soluble leukocyte, endothelial and platelet selectins (sL-selectin, sE-selectin, sP-selectin), soluble intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 (sICAM-1 and sVCAM-1). Their variations induced, in hemodialysis patients, by a dialysis run were thereafter studied RESULTS: Values of FVIIa, FVIIa/FVIIAg ratio, sTF, TFPI, TF-dMPA, D-Di, sTM, microP, sL, sE and sP selectins, sICAM-1 and sVCAM-1 increased all along the hierarchy HC group/ND group/D group. Microparticles were mainly of platelet origin, to a lesser extent of monocyte origin. Dialysis induced an increase of FVIIa, sTF, TF-dMPA and circulating markers of cellular activation/injury. Strong correlations were observed between FVIIa/FVIIAg ratio and serum creatinine levels, sTF, TF-dMPA, sTM, sE-selectin, sVCAM-1. The TF-aPC was impaired in the ND and the D group, and the lower values were, in the D group, associated with antecedents of vascular access thrombosis. CONCLUSION: Renal insufficiency is associated to an activation of the tissue factor coagulation pathway, to a platelet, monocyte and endothelial activation/injury and to a deficient tissue-factor induced response to activated protein C which culminate in end-stage disease and are increased by hemodialysis runs. This contributes to linked coagulation and cellular conditions for an enhanced atherosclerosis progression. Due to the TF pathway activation, the therapeutic use of recombinant TFPI should be evaluated.

[Voluntary lithium salt poisoning; risks of slow release forms]. / Intoxication volontaire par les sels de lithium; risques de la forme retard.

Lithium carbonate has been an invaluable drug in the treatment of manic-depressive illness. At the present time slow-release forms are available for better stability of circulating drug level with one daily take. However the better stability of lithiemia with these forms has to be balanced with a higher toxic risk in cases of lithium carbonate overdose because of continuous release. We report three cases of overdose with sustained-release lithium salts reaching life threatening complications. Two hemodialysis sessions were necessary to control plasma lithium levels. In two cases, lithiemia rebond was observed after the first hemodialysis session, and was associated with severe neurological disorders. This publication pointed out the therapeutic rule of at least two hemodialysis sessions in cases of severe slow release lithium carbonate salts intoxication.

Pulsed Doppler sonography for the guidance of vein puncture: a prospective study.

Blind deep venous puncture is an invasive procedure with risks of serious complications compromising the availability of veins for future punctures or endangering the patient's life. We designed a new hand-held pulsed Doppler probe for coaxial guidance of the puncture needle and a dedicated pulsed Doppler device displaying the depth of the measurement volume. We used this technique prospectively in two independent centers (the nephrology department and the intensive care unit) involving senior as well as junior staff members. Either the non-Doppler or the Doppler method were randomly selected for subclavian vein catheterization in 100 patients and for internal jugular vein catheterization in 30 patients. The success rate on the first attempt was 86.2% for the non-Doppler method versus 96.8% for the Doppler method (p = 0.03). The failure rate of the non-Doppler method used by junior staff members was 9.2%, reduced to 1.5% (p = 0.05) by secondary use of the Doppler method and/or help from a senior staff member (rescue procedure). Pulsed Doppler guidance reduced significantly the failure rate of venous punctures especially when used by seniors or by juniors after a training period.

Subcutaneous erythropoietin administration in predialysis patients: a single centre prospective study.

Since 1991 we have used subcutaneous administration of recombinant human erythropoietin (rHuEpo) in predialysis patients selected on the basis of chronic anaemia [haemoglobin (Hb) < 7.5 g%] without any extrarenal cause and chronic renal failure with a creatinine clearance of less than 10 ml/min. rHuEpo was given to 16 predialysis patients with nephropathy, due to chronic glomerulonephritis in all 12 of the cases. The sex ratio was 1:1 and mean age was 65 +/- 9 years (range 43-87). Hb was 7 +/- 0.4 g%. rHuEpo was injected subcutaneously thrice weekly while iron was given orally systematically before rHuEpo administration. Follow-up was performed monthly until dialysis (mean 9 months). Anaemia was corrected in all cases (Hb 11 +/- 0.5 g%). Mean Epo dose was 53 +/- 26 IU/kg/week in males and 47 +/- 11 IU/kg/week in females. Iron was systematically added (Fe2+ 8.2 mg/kg/week). Every patient had improved physical and intellectual ability after rHuEpo within the first month. No adverse side effects were noted but all patients were under antihypertensive therapy (one to three drugs). Serum potassium was unchanged. Mean creatinine before treatment was 507 mumol/l, and was 820 mumol/l after the treatment. Progression of renal failure was only affected by rHuEpo in one patient. In this case renal failure progression decreased. There was no significant alteration in the slope of the creatinine curve from 12 months before to after rHuEpo. Ten patients underwent dialysis (five CAPD, five haemodialysis), while six remained dialysis free. From January 1991 to December 1993 rHuEpo was given to 12.3% of the end-stage renal failure patients on dialysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased cardiovascular risk factors and features of endothelial activation and dysfunction in dialyzed uremic patients.

Due to the incidence of symptomatic atherosclerosis in uremic patients, hemostasis-derived cardiovascular risk factors, basal plasma concentrations of some endothelial-derived glycoproteins and desmopressin-induced variations of endothelial-derived proteins were studied in 22 uremic patients on prolonged maintenance hemodialysis with no cardiovascular antecedent. Compared to control subjects, patients had increased predialysis hemostasis-related cardiovascular risk factors: high fibrinogen, proconvertin, and type 1 plasminogen activator inhibitor plasma concentrations; low albumin values; generally low antithrombin III values but sometimes high. They had high predialysis plasma concentrations of endothelium-derived glycoproteins: von Willebrand factor, tissue-type plasminogen activator and urokinase-type plasminogen activator, which are secreted by endothelial cells, but also soluble thrombomodulin, a marker of endothelial cell injury. The desmopressin-induced release of tissue-type plasminogen activator and of von Willebrand factor were lower than in controls. High fibrinogen, type 1 plasminogen activator inhibitor and low albumin plasma concentrations may be linked to repeated acute phase reactions associated with hemodialysis. Data concerning endothelium-related proteins are concordant with the co-existence of a chronic in vivo endothelial activation and endothelial injury in uremia. This could be linked to the initiation and progression of atherosclerosis.

[Continuous guidance for venous punctures using a new pulsed Doppler probe: efficiency, safety]. / Guidage continu des ponctions veineuses par une nouvelle sonde Doppler pulsée: efficacité, sécurité.

Serious complications may occur after "blind" profound venous puncture in intensive care units. To secure these punctures, we designed a new fingertip pulsed Doppler (FPD) 5 MHz probe with a lateral to center indentation to guide the needle into the ultrasonic flux. A specific ultrasound analyzer indicating depth and diameter of the vessel was made for this use. The material was first tested in an experimental animal study. Results of animal venous punctures were successful 20/21. This material was then tested on patients with previous failure of "blind" punctures: results of 4 FPD punctures were successful in all 12 cases but one (catheterization not completed). We started a prospective multi-unit randomized study with various operators (junior residents, senior staff members), compared the success rate and type, the procedure duration of blind standard versus FPD punctures. We conclude in the safety and easy use of the FPD for central venous punctures.

[Tunneled jugular catheters in chronic hemodialysis: report from a Center apropos of 101 cases]. / Cathéters jugulaires tunnellisés chez l'hémodialysé chronique: bilan d'un centre à propos de 101 cas.

Since 1984, internal jugular vein cannulation (I.J.V.C.) was performed in our Center for ESRD patients. 202 catheters were implanted in 79 patients. Our population was divided in 2 groups: group I corresponding to a rescue procedure for the chronic vascular access failure, group II corresponding to chronic implantation. Outcome analysis indicate the follows results: in both groups, the first I.J.V.C. withdrawal cause was a functional AV fistula. Infections were observed only in group II. Thrombosis is not infrequent requiring fibrinolytic drugs with a 54 FF per patient year additive cost. A special nurse training protocol is also required to reduce the thrombosis incidence. Accidental withdrawal occurred in 11% cases of group II. This observation underlines the need of better fixation devices.

[Rapidly progressive glomerulonephritis treated by apheresis. A major economic challenge]. / Glomérulonéphrites rapidement progressives traitées par aphérèse. Un enjeu économique majeur.

Since 1983, 28 patients with a rapidly progressive glomerulonephritis were treated with apheresis. Seventeen patients had a primary glomerulonephritis, while 11 had a secondary form. Pathological pattern showed crescentic glomerulonephritis in all cases but one. In 23 cases of 28, renal survival was compromised within a few months. Apheresis were performed with the filtration technique, using a single needle device and central venous catheter. Plasmafilters were reused since 1984. In 1987, cascade filtration was introduced. The procedure was under permanent medical control. Mean reuse rate was 6 time. Renal actuarial survival curve showed a 60%, 42% and 21% survival rate at respectively 1, 2 and 5 years. Five deaths were noted. No death occurred during the apheresis procedure. The mean cost of filters and blood lines was 490 French francs (FF) per session; the mean cost of an haemodialysis session was 1900 FF. When the real survival time was compared to the expected renal failure without apheresis (assuming a linear progression of the disease), patients with a positive response to apheresis saved 488 dialysis months. The amount saved was 12 MFF. The additive cost of inefficient apheresis was 0.06 MFF. These data have to be considered on a 0.5 M inhabitants population basis during a 10 year survey.

[Encapsulating peritonitis after chronic peritoneal dialysis. Apropos of 3 cases]. / Péritonite encapsulante au décours de la dialyse péritonéale chronique. A propos de 3 cas.

Encapsulating peritonitis has been recognized as a life threatening, evolutive complication of chronic ambulatory peritoneal dialysis. Three cases are reported. Etiological factors are multiple, the diagnosis is suspected on peritoneal clinical signs, partial small bowel obstruction and impaired ultrafiltration. Barium studies and CT scan show small bowel enclosed within a peritoneal cocoon, prolonged transit time, wall thickening and a trabeculated fluid collection. Laparotomy confirms the diagnosis and reveals the pathological stage of disease. The surgical treatment consists of striping away the encapsulating membrane if possible while multiple incisions and loops release are indicated in other cases. The prognosis is poor unless an early surgical treatment is done.

Autoantibody to plasma fibrinopeptide A in a patient with a severe acquired haemorrhagic syndrome.

We describe a 50-year-old man with a severe acquired haemorrhagic syndrome. He had slightly prolonged clotting times using bovine thrombin, human thrombin and reptilase. His plasma contained a polyclonal IgG which interfered with the generation of fibrin monomers without inhibiting the aggregation of preformed monomers. The inhibitor delayed thrombin-induced fibrinopeptide A release. The IgG bound to insolubilized synthetic fibrinopeptide A (one binding site per molecule) and, with higher affinity, to fibrinogen (two binding sites per molecule). It did not bind to insolubilized fibrin monomers. The IgG did not impair the catalytic activity of thrombin toward a small synthetic substrate but inhibited the binding of thrombin to fibrinogen without binding to thrombin. The binding of the anti-fibrinopeptide A autoantibody to fibrinogen might have impaired thrombin-induced fibrinogen to fibrin conversion in vivo. This may have favoured the reported haemorrhagic syndrome which was associated with severe chronic renal insufficiency.

[A severe epidemic of Streptococcus group G infection in hemodialysis: epidemiologic survey by molecular biology and preventive measures]. / Epidémie d'infection sévère à streptocoque G en hémodialyse: enquête épidémiologique par biologie moléculaire et mesure préventive.

An outbreak of group G streptococci infection affected 6 patients of an hemodialysis unit. Group G streptococci were isolated from patients and from numerous atmospheric specimens, different parts of two dialysis machines, and two blankets, but from only one nurse on the hospital staff. Typing of group G streptococci by an improved method of DNA fingerprinting showed that the isolates from one patient, the nurse and the two blankets differed from one another. The group G streptococci were probably transmitted to patients by dialysis machines with defective microporous filters. No further case of group G streptococci infection was reported three years later since microporous guard filters were systematically doubled.

Effects of pancreastatin on pancreatic hormone secretion in the dog.

In the anaesthetized dog, porcine pancreastatin (98 pmol/min) was infused for 10 min into the pancreaticoduodenal artery either alone or during infusion of glucose. Blood was sampled from the pancreaticoduodenal vein. We found that pancreastatin inhibited pancreatic insulin output only under normoglycaemic conditions. Furthermore, pancreastatin significantly stimulated pancreatic glucagon and somatostatin outputs both during normo- and hyperglycaemic conditions. Our results show that pancreastatin has the capability to affect directly the three pancreatic hormone secretions in dogs.