Search Results
Results 351 - 400 of 1248
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Jaberi A - - 2007
PURPOSE: The creation of a vascular access is necessary in hemodialysis patients, including those with marginal vessels. Upper arm fistulae are attractive due to the ease of creation and of achieving high access flow rates. Cephalic arch stenosis (CAS) can lead to failure of upper arm fistulae and is increasingly ...
Donmez Ayhan - - 2007
We retrospectively evaluated 276 short-term femoral venous dialysis catheters (STFVCs) used for the collection of peripheral blood progenitor cells (PBPCs). Patients were not given any prophylactic antibiotic or anti-thrombotic therapy. Totally 877 leukapheresis sessions were performed. STFVCs were sufficient for continuous flow rate in all leukapheresis session. Side effects were ...
Gross M - - 2007
The measurement of ionic dialysance by conductivity variation is an established method in diffusive hemodialysis. To extend the validity of this method for use in highly convective therapies, such as online hemodiafiltration, we derived a new model for the measurement of ionic dialysance. This method was validated in a study ...
Tosun O - - 2007
BACKGROUND: Retrobulbar hemodynamic alterations can occur during hemodialysis sessions, and patients with chronic renal failure may experience visual problems. PURPOSE: To evaluate the effect of single-session hemodialysis on retrobulbar vessel hemodynamics by color Doppler ultrasonography. MATERIAL AND METHODS: Thirty-five patients were included in the study. Retrobulbar blood flows were examined ...
Lagali Neil S - - 2007
The diffuse reflection spectrum in the 500-1670 nm region for whole blood taken from healthy subjects and end-stage renal disease (ESRD) patients was measured to test the feasibility of optically monitoring ESRD and its treatment by hemodialysis. Spectral regions where optical absorption significantly differed between healthy subjects and ESRD patients ...
Zinovik Igor N - - 2007
A computational fluid dynamic (CFD) model was developed and used to simulate blood flow associated with our pulsating respiratory catheter. A principal goal of this CFD study was to evaluate how the balloon-generated flow permeated through the fiber bundle and interacted with the flow past the catheter. The simulation showed ...
Dasselaar Judith J - - 2007
Monitoring of relative blood volume changes (DeltaRBV) has been propagated for the prevention of hemodialysis hypotension. Although the influence of ultrafiltration volume on DeltaRBV is well-known, there is no mention in the literature that DeltaRBV results should be interpreted differently for the first, second, or third hemodialysis session of the ...
Schneditz Daniel - - 2007
The duration, accuracy, and reproducibility of a new access flow measuring technique was analyzed in a series of in vitro experiments using an extracorporeal line switch that allowed for almost instantaneous reversal of extracorporeal blood flow without disconnecting the blood lines. Access flow was modeled from the magnitude and time ...
Capodicasa E - - 2007
BACKGROUND: Isoprene, a volatile hydrocarbon produced by the human organism, is currently being extensively investigated because the mechanisms underlying its endogenous origin are unknown and because experiments suggest it is toxic and cancerogenous. Previous reports of increases in breath isoprene concentrations during 4-hour, thrice-weekly hemodialysis, but not during continuous ambulatorial ...
Thermann Florian - - 2007
BACKGROUND: Dialysis shunt-associated steal syndrome (DASS) is a rare complication of hemodialysis access (HA) which preferably occurs in brachial fistulas. Treatment options are discussed controversially. Aim of this study was to evaluate flow-controlled fistula banding. MATERIALS AND METHODS: Patients treated between 2002 and 2006 were included in this prospective survey. ...
Eloot Sunny - - 2007
BACKGROUND: To reduce infection risks in patients on hemodialysis with a long term central venous catheter, different types of closed luer lock access devices are used on the arterial and venous catheter hub. Although those connectors create a mechanically and microbiologically closed system in between two dialysis sessions, no data ...
Wijnen E - - 2007
A reduction in vascular access flow poses a risk for thrombosis. We present a new technique to measure vascular access flow during dialysis based on extracorporeal temperature gradients, and their changes, on reversing the extracorporeal bloodlines without having to inject an indicator. Fistula temperatures were measured by the blood temperature ...
Dell'Aquila Roberto - - 2007
Automated peritoneal dialysis (APD) has undergone substantial growth in recent years because of an increased demand for higher doses of peritoneal dialysis (PD) treatment and a need to improve quality of life for patients. The evolution of this treatment is closely linked with the development of new automatic machines and ...
Ash Stephen R - - 2007
Over 60% of patients initiating chronic hemodialysis in the United States have a chronic central venous catheter (CVC) as their first blood access device. Although it would be better if these patients started dialysis with fistulas, the CVC is used because it is a reliable and relatively safe method for ...
Prohovnik Isak - - 2007
Patients with end-stage renal disease (ESRD) undergoing hemodialysis are known to suffer cognitive deficits and stroke of unknown etiology. It has been suspected that the treatment itself may contribute to the syndrome by unknown mechanisms, which we investigated in this study. End-stage renal disease patients on hemodialysis (n=19) or peritoneal ...
Shemesh David - - 2007
In our center, we start hemodialysis using arteriovenous accesses empirically 1 mo after surgery in nearly all patients, when the vein diameter reaches 5 mm and blood flow is assumed to be adequate. We measured blood flow and vessel diameter in the maturing autogenous and prosthetic access to determine if ...
Kanno Yoshihiko - - 2007
BACKGROUND: A double-lumen catheter (DLC) is used as a temporary blood access in emergency haemodialysis and continuous haemodialysis. There are various reports concerning thrombosis related to use of DLC and other catheters. The objective of this study is to assess the incidence of venous thrombosis when using DLC in patients ...
Stegmayr Bernd - - 2007
We previously showed, in vitro, that micro bubbles pass the air trap without inducing an alarm. The aim was to investigate if micro bubbles bypass the detector during hemodialysis (HD). During HD (40 patients, 47 HD sessions, 231 measurements), an ultrasound detector was fixed just after the venous air trap. ...
Kato Tatsuo - - 2007
A higher beta(2)-microglobulin (beta(2)MG) removal rate is possible in dual-dialyzer hemodialysis (DDHD) because of the large internal filtration provided. In this treatment, in the first dialyzer, a large amount of water moves from the blood side to the dialysate side, and in the second dialyzer, it moves from the dialysate ...
Seyahi Nurhan - - 2007
BACKGROUND/AIMS: Ideal time needed for arteriovenous fistula (AVF) maturation is still controversial. In this study, we aimed to investigate the natural course of AVF maturation and also investigated the factors affecting AVF maturation. METHODS: We studied 31 (21M/10F, mean age 55.8 +/- 16.2) chronic renal failure patients. We evaluated the ...
Yamamoto Ken-Ichiro - - 2007
Rexeed was developed by Asahi Kasei Medical using wave-shaped hollow fibers, a full baffle, and a short taper housing to improve dialysate flow. The present study is clarifies improvement in dialysate flow with Rexeed-15 compared with that of a conventional dialyzer. Dialysate flow was evaluated by the pulse-response method. Dialysate ...
Yamashita Akihiro C - - 2007
BACKGROUND: Prescribing therapeutic conditions for online predilution hemodiafiltration (HDF) with fixed total dialysate flow rate Q(Dtotal) is not straightforward, since the increase in the substitution fl ow rate Q(S) is compensated by the decrease in the net dialysate flow rate Q(Dnet). METHODS: Clearances of various solutes under online predilution HDF ...
Ghezzi Paolo M - - 2007
In recent years the concept of biocompatibility is not limited to the dialytic membranes, but has been substituted by a more general viewpoint where all the parameters of the dialytic treatment are taken into consideration: the interaction of blood-surfaces (the dialyzer in all its components and the hematic lines), the ...
Ronco Claudio - - 2007
The efficiency of a hemodialyzer is largely dependent on its ability to facilitate diffusion between blood and dialysis solution. The diffusion process can be impaired if there is a mismatch between blood and dialysate flow distribution in the dialyzer. For this reason it is important that average and regional blood ...
Colussi Giacomo - - 2007
In hemofiltration (HF) and hemodiafiltration (HDF), removal of medium and high-molecular-weight solutes is greatly enhanced by convective mechanisms as compared with simple diffusion; increasing convective flows may allow greater removal rates of these solutes. Use of "predilution" (pre-H[D]F) may allow higher ultrafiltration rates than the "postdilution" mode (post-H[D]F); yet, the ...
Shinzato Toru - - 2007
Push/pull hemodiafiltration is characterized by alternate filtration and backfiltration, while sterile pyrogen-free dialysate is flowing through a hemodiafilter. During the filtration phase, uremic substances are eliminated not only by diffusive, but also by convective transport. During the backfiltration phase, dialysate is quickly pushed to the blood side (i.e. backfiltration) so ...
Ronco Claudio - - 2007
The evolution of hemodiafiltration (HDF) has become possible by the advances in the construction of dialysis membranes. The availability of a high-flux membrane, partially hydrophilic with high sieving coefficients and a reduced wall thickness has made it possible to conveniently combine diffusion and convection for blood purification. The second important ...
Ozmen Namik - - 2007
OBJECTIVE: To investigate whether or not P-wave dispersion (PWD) can be used as a good indicator of effective hemodialysis. SUBJECTS AND METHODS: The study included 35 patients (20 males, 15 females, mean age 61 +/- 10 years) who regularly received hemodialysis treatment for chronic renal failure. Following hemodialysis, the patients ...
Wizemann Volker - - 2007
The distinction between high-efficiency haemodiafiltration (HDF), usually applied with online preparation of substitution fluid, and 'classic' low-efficiency HDF (using less than 15 litres of substitution fluid) makes sense since the magnitude of convection (expressed by substitution volume) is important for the claimed benefits of HDF. Many experimental and observational data ...
Unger Juliane K - - 2007
Small intravascular volume, pathophysiological hemorheology, and/or low cardiac output [CO] are assumed to reduce available blood flow rates via common dual-lumen catheters (except for those with a right atrium catheter tip position) in the critically ill patient. We performed an experimental animal study to verify these assumptions. Anesthetized, ventilated pigs ...
Eloot S - - 2006
Dialyser manufacturers only provide limited information about mass removal under well-defined flow and solute conditions in commercially available dialysers for hemodialysis. This computational study aimed at assessing the solute transport efficiency in a dialyser for different geometries (fiber lengths and diameters). A three-dimensional finite volume model of a single fiber ...
Zanow Juergen - - 2006
This study used intraoperative monitoring of the access flow to evaluate the results of flow reduction in the management of high-flow arteriovenous access-related symptoms of distal ischemia and cardiac insufficiency. A retrospective study was conducted of 95 patients (78 with ischemia, 17 with cardiac failure) who underwent flow reduction between ...
Pilcher Thomas A - - 2006
BACKGROUND: Both actively cooled-tip and large-tip catheters are currently available clinically to create large endomyocardial lesions during application of radiofrequency (RF) energy. The purpose of this study was to compare the effect of convective cooling at physiologic flow rates on RF lesion size using both actively cooled and large-tip catheters. ...
Sombolos K - - 2007
BACKGROUND: The aim of the present study was to assess hemoglobin changes occurring at the beginning of high-flux hemodialysis (HD). METHODS: In a group of 20 chronic HD patients (group A), total hemoglobin (tHb), hematocrit (Hct) and total serum proteins (TP) were measured in blood samples drawn from an arterial ...
Ronco Claudio - - 2006
The efficiency of a hemodialyzer is largely dependent on its ability to facilitate diffusion, as this is the main mechanism by which small solutes are removed. The diffusion process can be impaired if there is a mismatch between blood and dialysate flow distribution in the dialyzer. The objective of the ...
Lagali Neil - - 2006
Visible and near infrared transmission and diffuse reflection spectroscopy were used to monitor changes in whole blood resulting from hemodialysis treatment for end-stage renal disease. Blood samples from 8 patients on chronic hemodialysis therapy were measured in the 500- to 1700-nm wavelength range immediately before and after a single treatment. ...
Everdell N L - - 2007
A prototype dialysis system for the treatment of premature babies has been designed, built and successfully tested. It can be used to treat babies who are suffering from renal failure or metabolic disorders. These patients are difficult or impossible to treat conventionally, due to their very small total blood volume ...
Amano Izumi - - 2006
In cases of vascular access (VA) for hemodialysis including arteriovenous fistula and arteriovenous graft, venipuncture and hemostasis are usually repeated three times a week. Accordingly, it is assumed that VA vascular disorders are worsened following long-term hemodialysis. In particular, angiostenosis frequently occurs and results in insufficient blood flow or increased ...
Kondepati Venkata Radhakrishna - - 2006
Application of mid-infrared spectroscopy for the determination of urea in blood plasma dialysates of microliter sample volumes using a transmission microcell was investigated. Infrared spectra of the dialysates of plasma samples collected from 75 different patients using CMA 60 microdialysis catheters were evaluated with multivariate partial least squares regression. Using ...
Lindsay Robert M - - 2006
Measurement of blood flow rate (Qa) is used to monitor arteriovenous fistulas and grafts that are used for hemodialysis blood access. Most Qa measurements use indicator dilution techniques to measure the recirculation that is induced by the reversal of hemodialysis blood lines. R plus the dialysis circuit flow (Qb) allows ...
Leypoldt John K - - 2006
New daily hemodialysis therapies operate at low dialysate flow rates to minimize dialysate volume requirements; however, the dependence of dialyzer clearances and mass transfer-area coefficients for small solutes on dialysate flow rate under these conditions have not been studied extensively. We evaluated in vitro dialyzer clearances for urea and creatinine ...
Wijnen Edwin - - 2006
Periodical access flow measurements can predict the development and presence of vascular access flow-limiting stenosis and subsequent thrombosis. Access flow measurement has become a standard in vascular access care. Different techniques to measure access flow are available. The aim of this study was to compare an integrated access flow measurement ...
Jin Fan - - 2006
Using a special double-layer membrane to avoid interaction among flow fields generated by different pores, we have, for the first time, observed the predicted discontinuous first-order transition in ultrafiltration of flexible linear polymer chains. Namely, the chain could pass through a pore much smaller than its unperturbed radius only when ...
Courrol Lilia C - - 2006
We introduce the use of a lanthanide complex, tetracycline-europium, for the clinical diagnosis of urea hydrogen peroxide in human whole blood. The values obtained agree with the urea concentration variation verified in 49 patients, including 12 predialysis, 12 peritoneal, and 15 dialysis subjects, and 10 controls. This method is noninvasive ...
Uhlin Fredrik - - 2006
BACKGROUND: An on-line monitoring system for dialysis dose calculations could make it possible to provide an adequate dialysis dose that is consistently given to haemodialysis (HD) patients. The aim of this study was to compare dialysis dose (Kt/V) using four different methods and their sensitiveness to a reduction in clearance. ...
Lindley Elizabeth J - - 2006
The discussion explored and expanded on the issues raised by Dasselaar et al in their review of the measurement of relative blood volume (RBV) changes during dialysis (NDT 2005). Dialysis machines incorporating blood volume monitoring and control are widely available in Europe. The use of continuous blood volume monitoring (CBVM) ...
Mandolfo S - - 2006
Blood flow rate is a critical factor in the achievement of an adequate dialysis dose. The aim of this review is to evaluate the possibility of optimizing dialysis dose in terms of Kt/V in patients with reduced vascular access (VA) flow rate, considering effective blood flow (Qb eff), recirculation, access ...
Evenepoel Pieter - - 2006
Albumin dialysis by the molecular adsorbents recirculating system (MARS) and by fractionated plasma separation, adsorption, and dialysis (Prometheus[PROM]) represent novel nonbiological liver support systems specifically designed to remove albumin-bound substances. Preliminary evidence suggests a favorable impact of MARS on the course and outcome of liver failure. This study aimed at ...
Patzer John - - 2006
Toxins that bind to albumin in the bloodstream and are associated with progressing liver failure have proven refractory to removal by conventional hemodialysis. Such toxins can, however, be removed by adding a binder to the dialysate that serves to capture the toxin as it is dialyzed across the membrane. Several ...
Unger Juliane K - - 2006
BACKGROUND: Main factors for the overall performance of haemofilters (HF) are membrane features and filter durability without clogging/clotting of capillaries. However, the venous line resistance (Pv) is a powerful force for net filtrate flux resulting in haemoconcentration and thus is enhancing the phenomenon of membrane clogging. Therefore, we hypothesized that ...
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