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Biomedical subjects

B Canaud

Publications and source records attributed to B Canaud.

148 records · Page 9Linked to original sources
PubMedDate not supplied

Beta-2 microglobulin serum levels in maintenance dialysis. What does it mean?

beta-2 Microglobulin levels (beta-2M) were analyzed at four month intervals in sera of 237 patients on various forms of dialysis over a 2 year period; twelve patients volunteered to participate in short-term kinetics studies. Duplicate beta-2M measurements in biologic fluids were performed using an RIA kit. The data presented confirm elevated serum beta-2M in dialyzed patients whatever the dialysis method used and give an overview on various factors affecting circulating serum beta-2M. Intraindividual beta-2M variations were 13% in stable ESRD patients. Unusually high values (greater than 2 SE) were observed in patients presenting with severe intercurrent disease (e.g., cancer). The only significant difference observed between groups of patients, HD (46 +/- 1 mg/L) and PD (IPD: 33 +/- 3, CAPD: 37 +/- 2 mg/L), was due to the residual renal function preserved in a higher percentage of PD patients. No significant difference was noted in HF (40 +/- 2 mg/L) and HDF (38 +/- 5 mg/L) patients, despite a higher beta-2M removal rate. beta-2M membrane permeability differs greatly among filters. It is high for AN69 and Polysulfone, intermediate for Polyamide, low for Polyacrylonitrile and none for Cuprophane. Peritoneal membrane is highly permeable to beta-2M with beta-2M dialysate/serum levels of 0.20 at the end of a 6 hr exchange. In conclusion, beta-2M determination in uremic patients is useful in assessing material permeability and biocompatibility. However, it is too early to determine the impact or the beneficial effects of using highly permeable membrane to prevent beta-2M-amyloidosis related nonarticular complications.

Adult↗
PubMedDate not supplied

A portable artificial compact kidney: pack system.

To facilitate patients' movement, we developed a simplified portable haemodialysis system, using a sorbent cartridge (Organon Teknika) for regeneration of the dialysate. The whole system is in two parts: (1) a compact disposable container for dialysate recirculation with dialyser and blood and dialysate lines; (2) a dual functions circulatory assistance monitor. The pack system is easy to use: single-use; no water processing; no formalin processing; reliable for temporary use (because of its aluminium), providing excellent purification; compact and portable, it permits greater freedom for the patient, and with adequate dialysis.

Equipment Design↗
PubMedDate not supplied

Direct determination of blood recirculation rate in hemodialysis by a conductivity method.

Blood recirculation is one of the key factors of decreasing dialysis efficiency. Determination of recirculation rate (R) is necessary to optimize effective dialysis delivery and to monitor vascular access function. R can be directly measured by a conductivity method in paired filtration dialysis (PFD), a double-compartment hemodiafiltration system that permits direct access to plasma water via the ultrafiltration stream. Measurement of R, in this system, involves the first of two conductivity sensors integrated in a urea monitor (UMS, BelIco-Sorin, Mirandola, Italy), and two saline injections. The rise in conductivity (deltaC1) induced by a 2.7 ml bolus of hypertonic saline 20% (mg/dl) in the arterial line serves for calibration, and is followed by an equivalent injection into the venous line, giving rise to deltaC2. The ratio deltaC2/deltaC1 equals R. A comparison between R values obtained with this method and with the low-flow technique in 31 chronic dialysis patients during 138 PFD sessions is reported. Mean R+/-SD by the conductivity method was 5.1+/-2.0 and 5.7+/-2.0% after 65 and 155 minutes of PFD (correlation coefficient, r = 0.75), whereas it was 6.4+/-4.9% and 5.5+/-4.6% after 30 sec of low blood pump flow for urea and creatinine markers, respectively (r = 0.35). After 120 sec of low flow, mean R increased to 9.0+/-5.1 and 8.8+/-4.6% for urea and creatinine, respectively (r = 0.45). Considerable discrepancies were found in R values measured simultaneously with the two blood markers. Statistically significant differences were found between the two measurement modalities (blood-side and conductivity); the correlation coefficients (r) varied between 0.28 and 0.41. The observed differences in mean R results do not seem considerable from a clinical perspective. The best agreement between blood-side and conductivity R measurements was obtained with Rcreat after 30 sec of low flow. Overall, a wider distribution was found in R values from blood-side determinations, most likely consequent to variability in the dosing method. The conductivity method appears more accurate and simple in assessing total R, and can be readily automated and integrated into the dialysis machine. The authors, therefore, recommend evaluation of R using methods not based on chemical blood concentration values.

Adult↗