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C Mion

Publications and source records attributed to C Mion.

At least 19 recordsLinked to original sources
PubMed1999

Analysis of the influence of the infusion site on dialyser clearances measured in an in vitro system mimicking haemodialysis and haemodiafiltration.

BACKGROUND: Blood flow (QB), dialysate flow (QD), and dialyser characteristics are the three major factors driving dialysis efficacy. Haemodiafiltration has added an increased convective volume to increase efficacy. We aimed to assess the influence of the infusion site of the replacement fluid in an in vitro system emulating haemodiafiltration. METHODS: An in vitro system allowing us to control the dialysate temperature, concentration gradient, the flow of both dialyser sides over a range wider than that compatible with clinic, was set to evaluate the influence of the different parameters on dialysis efficacy. The total ion clearance was used as an accepted method for small molecule clearance assessment. Cellulose triacetate (CT190C, Baxter; FB170U, Nipro) and polysulfone (HF80, Fresenius) dialysers were included in the study. Dialysis as well as on-line diafiltration both with pre- and postdilutional infusion were assessed. The experimental conditions presented in this study included QD 620 and 970 ml/min. The convective flows ranged from 50 to 200 ml/min. RESULTS: For a QD = 620 ml/min and a QB = 350 ml/min the total ion clearance ranged from 269 to 274 for HF80, from 291 to 294 for FB170 and from 294 to 302 for CT190. The variability of the measurements was very low (SD < 1%). Total ion clearance increased by 17-21% when QB was raised from 300 to 400 ml/min. Increasing QD from 420 to 970 ml/min (for QB = 350 ml/min), resulted in an increase in total ion clearance which was more marked at lower QD (from 420 to 620 ml/min) and plateaued thereafter (from 620 to 970 ml/min). Postdilutional on-line diafiltration with 100 ml/min of infusate resulted in an additional increase in total ion clearance of 5.4-8.6%. This increase was proportional to the infused volume. On the contrary, predilutional on-line diafiltration resulted in a decrease in total ion clearance which was also proportional to the infused volume (between -5.1 and -6.9% at 100 ml/min infusion volume and -9.7 to -12.9% at 200 ml/min). CONCLUSIONS: The present in vitro system provided accurate and reproducible results on dialyser clearances. Our experiments confirmed previous studies on the influence of QB and QD on dialyser efficacy. Further, they show that the proportional increase in postdilutional on-line diafiltration is lesser than that previously reported. More importantly, they also show that pre-dilution infusion in high efficiency systems results in a drop in dialyser clearance compared to dialysis alone, again proportional to the infusion rate. Thus, increasing the convective flow may increase dialysis efficacy even more than increasing QD alone. However, the choice of infusion site is crucial to obtaining this benefit in small molecule clearances.

Hemofiltration↗
PubMed1998

Seasonal changes in blood pressure in patients with end-stage renal disease treated with hemodialysis.

BACKGROUND: Many factors contribute to the regulation of blood pressure. The role of climate has received relatively little attention. METHODS: During a four-year period, we determined the influence of climate on blood pressure in 53 patients with end-stage renal disease treated with hemodialysis. For each patient, blood pressure was measured before each of three dialysis treatments per week for an average of 31 months. The dose of dialysis (urea clearance multiplied by the length of dialysis and divided by the distribution volume of urea) and protein catabolism rate were assessed monthly. We then analyzed the monthly mean values for blood pressure, pulse, and body weight in relation to the monthly values for temperature, relative humidity, and atmospheric pressure recorded in Montpellier, France. RESULTS: The maximal monthly temperature varied from 10 degrees C in the winter to 31 degrees C in the summer, and the minimal monthly temperature from 1 degree to 20 degrees C. The mean (+/-SE) systolic and diastolic blood pressure was highest during the winter (153+/-3/82+/-2 mm Hg) and lowest during the summer (141+/-3/75+/-2 mm Hg). The seasonal pattern was evident throughout the four-year period. Blood pressure was correlated inversely with monthly maximal temperature (r= -0.65 and P<0.001 for systolic pressure; r= -0.71 and P<0.001 for diastolic pressure) and directly with minimal humidity (r=0.45 and P=0.002 for systolic pressure; r=0.43 and P=0.003 for diastolic pressure). Changes in protein catabolic rate, weight gain during dialysis, and dialysis dose were not related to changes in blood pressure. CONCLUSIONS: In patients with end-stage renal disease treated with hemodialysis, blood pressure varies seasonally, with higher values in the winter and lower values in the summer.

Blood Pressure↗
PubMed1998

Evaluation of high-flux hemodiafiltration efficiency using an on-line urea monitor.

On-line urea monitoring of the effluent dialysate offers a real-time assessment of dialysis efficiency and metabolic/nutritional characteristics of hemodialysis patients. Quantitative parameters were evaluated by dialysate urea kinetic modeling (DUKM) with an on-line urea sensor in 23 patients treated by high-flux hemodiafiltration (HDF) (215 sessions of 210 to 240 minutes with a mean blood flow rate of 367 +/- 44 mL/min). Overall, the mean effective Kt/V was 1.52 +/- 0.29, the urea mass removed (22.8 +/- 5.5 g/session or 814 +/- 198 mmol/session), the solute removal index (SRI) 73% +/- 6.1%, and the mean normalized protein catabolic rate (nPCR), 1.15 +/- 0.31 g/kg/day. Blood urea kinetic modeling (BUKM), based on pre- and postsession urea concentrations, using equations from Daugirdas and Garred to calculate equilibrated Kt/V and nPCR, respectively, were in good agreement with DUKM, the differences observed appearing not clinically relevant. The variability of evaluated parameters was verified over consecutive sessions for a mean period of 3 weeks in the entire group. Mean variation in Kt/V was 8%; in urea mass removal, 18%; and in nPCR, 18%. When assessed over 1 week in a subgroup of 13 patients, Kt/V and PCR remained relatively stable, and urea mass removal per- and postsession declined from 23.5 +/- 8.0 g (840 +/- 285 mmol) to 18.7 +/- 6.3 g (667 +/- 225 mmol) from the first to the third session of the week, most likely as a consequence of interdialytic intervals. Predialysis urea concentrations followed the same trend. In the current study, DUKM with on-line urea sensor has confirmed that HDF is a highly efficient renal replacement modality; the variability observed in quantitative parameters supports a need for frequent adequacy monitoring. On-line urea monitoring of effluent dialysate is a simple device that provides the opportunity to tailor treatment to patient needs.

Blood Urea Nitrogen↗
PubMed1998

On-line haemodiafiltration: state of the art.

Faced with the shortcomings of conventional dialysis on a long-term basis, as illustrated by the dialysis-related pathology, a need for a new strategy exists to improve the overall quality of treatment in end-stage renal failure (ESRF) patients. On-line haemodiafiltration (HDF) seems to be the best therapeutic option to achieve this goal at the present time. By enhancing convective clearances through highly permeable membranes, HDF offers the greatest solute fluxes both for low and higher molecular weight uraemic toxins. As for example, in our routinely performed HDF programme based on 3 weekly sessions lasting 3-4 h each, double-pool urea Kt/V achieved was 1.55+/-0.20 and beta2-microglobulin Kt/V was 0.91. By producing substitution fluid from fresh dialysate, the technique of HDF is simplified and becomes economically affordable. By improving the haemodynamic tolerance, HDF allows more elderly and high risk cardiovascular patients to be treated more safely. By using bicarbonate-buffered infusate, HDF facilitates the correction of acidosis. Both by using ultrapure bicarbonate dialysate and down-regulating the membrane reactivity via a 'protein cake', HDF introduces the first step for a full haemocompatibility concept. Finally, by giving access to virtually unlimited amounts of sterile and non-pyrogenic fluid, HDF should introduce new therapeutic options such as a totally automated and feed-back-controlled machine. Today's on-line HDF is already a step forward to enhance the overall efficacy of renal replacement therapy and to improve the global care of ESRF patients.

Hemodiafiltration↗
PubMed1997

Protein catabolic rate over lean body mass ratio: a more rational approach to normalize the protein catabolic rate in dialysis patients.

Protein catabolic rate (PCR), equivalent to dietary protein intake in "stable" dialysis patients, is widely accepted as a marker of their protein nutritional status. PCR is usually established from urea generation rate using urea kinetic modeling (UKM), but the normalizing factor is still a matter of controversy. By convention, PCR is expressed in grams of protein degraded daily divided by the dry body weight (BW) (nPCRBW). To be valid, this implies that dry BW is close to ideal BW and that body composition is preserved with a lean body mass (LBM) over BW ratio near 0.73. Such conditions being infrequently found in dialysis patients, it has been proposed to normalize PCR to ideal BW or to total body water, but these correction factors are not really appropriate. A more rational approach would be to express PCR as the ratio of protein degraded to the kilograms of LBM (nPCRLBM), thus offering the main advantage of directly coupling PCR to changes in protein or nitrogen reserve. In this study, we developed a combined kinetic model of urea and creatinine applied to the midweek dialysis cycle in 66 end-stage renal disease (ESRD) patients. UKM provided Kt/V and PCR, whereas creatinine kinetic modeling (CKM) was used to calculate LBM. Thirty-four patients with a preserved LBM (LBM/dry BW ratio equal to or greater than 0.70; mean ratio, 0.81 +/- 0.11) and with a dry/ideal BW ratio of 1.01 +/- 0.16 had a mean PCR of 1.14 +/- 0.30 g/kg/24 h when normalized to BW (nPCRBW) and of 1.40 +/- 0.30 g/kg/24 h when normalized to LBM (nPCRLBM). In the 32 patients with a reduced LBM (LBM/dry BW ratio, below 0.70; mean ratio, 0.60 +/- 0.09) and dry/ideal BW ratio of 1.11 +/- 0.23, the mean nPCRBW was 0.99 +/- 0.31 g/kg/24 h, whereas nPCRLBM was 1.62 +/- 0.32 g/kg/24 h. For both subgroups, Kt/V was similar, with mean values of 1.76 +/- 0.34 and 1.69 +/- 0.27. Normalizing PCR to LBM offers a double benefit: it compensates for the error induced by abnormal body composition (eg, obese patients) and permits PCR to be adjusted for the decrease in LBM that occurs with age. We propose nPCRLBM as a more rational index to express PCR in dialysis patients.

Aged↗
PubMed1996

Amyloidosis-related cauda equina compression in long-term hemodialysis patients. Three case reports.

STUDY DESIGN: These case reports illustrate the neurologic manifestations due to beta 2 microglobulin amyloid deposition at the lumbar spine level in long-term hemodialysis patients. OBJECTIVE: Radiologic investigations suggested the amyloid origin of extradural soft tissue deposition, which was confirmed by histologic examination after surgical excision. SUMMARY OF BACKGROUND DATA: Although cervical myelopathy is a recently recognized complication of long-term dialysis-related beta 2 microglobulin amyloidosis, neurologic manifestations due to amyloid deposition at the lumbar spine level have rarely been reported. METHODS: Three case reports of cauda equina compression in long-term hemodialysis patients are presented. Follow-up radiography, computed tomography, and magnetic resonance imaging were performed and patients underwent surgical decompression of the thecal sac. RESULTS: In two patients, the compression resulted from the development of a destructive spondylarthropathy, and from the infiltration of extradural spaces and ligaments by an abnormal soft tissue. The third patient had lumbar spinal stenosis due to multiple disc protrusion and to hypertrophy of facet joints and ligamentum flavum. Multilevel laminectomies enabled excision of an abnormal fibrous tissue responsible for the thecal sac compression. Histologic examination of the excised fibrous tissues disclosed amyloid deposits in intervertebral discs, apophysial joints, and ligaments. CONCLUSIONS: In long-term hemodialysis patients, cauda equina compression may develop as the consequence of beta 2 microglobulin amyloid deposition in lumbar intervertebral discs, facet joints, and ligaments. Magnetic resonance imaging is well suited to show the extent of the compression and supports the argument for the amyloid origin of extradural soft tissue.

Adult↗
PubMed1996

Oral vitamin D or calcium carbonate in the prevention of renal bone disease?

It is well known that hyperparathyroidism begins early in renal failure and progresses, probably not linearly, throughout the natural course of renal diseases and dialysis therapy. Recent progress in basic medical science has improved our understanding of the mechanisms by which the classically known stimuli for parathyroid hormone synthesis and secretion may act, including hypocalcaemia, hyperphosphataemia and vitamin D3 metabolism disturbances. In the treatment of hyperparathyroidism, although some authors stress the benefit of treating one of these stimuli, it is probably more effective to combine the treatment of them all. There is conclusive recent work showing the efficacy of using both CaCO3 and vitamin D3, either in chronic renal failure or in dialysis patients at every stage of hyperparathyroidism. Therefore, the treatment of hyperparathyroidism should start early, long before dialysis, and it should aim to correct any of the causal factors. Both CaCO3 and vitamin D3 derivatives may be used in the prevention and treatment of renal bone disease. The limits of this association are the increasingly often reported adynamic bone disease, which in our experience has not yet given major clinical problems, and hyperphosphataemia. Uncontrolled serum phosphate levels would counterbalance the beneficial effect of vitamin D3 derivatives on hyperparathyroidism.

Administration, Oral↗
PubMed1996

Extensive necrotizing livedo reticularis in a patient with chronic renal failure, hyperparathyroidism and coagulation disorder: regression after subtotal parathyroidectomy.

Necrotizing livedo reticularis is an infrequent, life-threatening complication of chronic renal failure. Since Selye's studies in 1962, calciphylaxis, i.e. acute calcium deposition in tissue, is considered the main pathomechanism, especially because hyperparathyroidism are very frequently present. However, other etiological and/or triggering factors, such as coagulation disorders, direct cellular toxicity of parathormone or calcium on endothelium, might be involved, acting perhaps in a cumulative way. We report a case with a circulating anticoagulant which supports this hypothesis.

Adult↗
PubMed1995

[Role of continuous ambulatory peritoneal dialysis (CAPD) in a program for the treatment of chronic renal insufficiency. Problems posed by transfer of CAPD to transplantation or hemodialysis].

Continuous ambulatory peritoneal dialysis (CPAD) is a fully recognized method for treating end stage renal disease patients. However, literature data in agreement indicating that CAPD is a treatment modality for short to mid-term period. Largest series show that technical survival for CAPD averaged 50% at 3 years. Transplantation, curing temporarily ESRD patients, represents a success exit for CAPD in only 25 to 30% of patients. CAPD does not impair long term success of renal graft. Post-operative morbidity related to peritoneal catheter (exit skin infection and peritonitis) and abdominal problems represents a significant risk that should be prevented by appropriate measures. Hemodialysis transfer, failure of the method, represents an exit modality in 50 to 60% of patients. Whatever causes of CAPD failure, psycho-social difficulties, inadequacy of dialysis, edema due to fluid excess, malnutrition, severe peritonitis, transfer to hemodialysis must be considered as soon as possible to prevent deleterious effects on patient survival. Such facts indicate that CAPD program must be associated with large and appropriate withdrawal hemodialysis facilities. CAPD may be also a waiting modality for hemodialysis patients faced with temporary or repeated vascular access problems. In this last case it must be emphasized that hemodialysis to CAPD transfer will reduce "dialysis dose" efficiency (e.g., urea Kt/V) by 50%. We conclude that rationale use of CAPD would provide an excellent treatment modality for end stage renal disease patients for a short or mid-term period of time.

Humans↗
PubMed1995

[Necrotic angiodermatitis revealing a secondary hyperparathyroidism due to chronic renal insufficiency: healing after subtotal parathyroidectomy].

Severe skin necrosis of poor prognosis have been rarely reported among chronic renal failure patients. Their clinical outbreak must rapidly lead to search for a secondary hyperparathyroidism. Early parathyroidectomy seems is the only treatment able to stop the progression of the skin lesions. From an original clinical observation we discuss the different mechanisms involved.

Adult↗
PubMed1995

Creatinine kinetic modelling: a simple and reliable tool for the assessment of protein nutritional status in haemodialysis patients.

While the mathematical modelling of urea kinetics is in wide use for evaluating treatment adequacy and protein nutrition in dialysis patients, the kinetics of creatinine generation in dialysis patients has been relatively unexplored. In this study creatinine kinetic modelling as a clinical tool was investigated in a group of 90 patients treated by haemodialysis (n = 20), haemodiafiltration (60), haemofiltration (7), or biofiltration (3) over a 6-36-month period. A single pool model of creatinine kinetics was employed to obtain monthly values of creatinine distribution space and creatinine appearance rate. Extrarenal creatinine degradation rate, estimated using a clearance of 0.038 l/kg/24 h as suggested by Mitch and co-workers, was added to creatinine appearance rate in urine and dialysate to calculate a corrected creatinine index (CI). Extrarenal degradation accounted for 12 +/- 2% of CI. CI was higher in males (22.4 +/- 4.5 mg/kg/24 h) than females (19.8 +/- 4.8) and decreased with age, falling off more sharply for the female group (CI = 29.9-0.185.age, R = 0.72) than the males (CI = 24.1-0.030.age, R = 0.31). CI was found to correlate strongly with protein catabolic rate determined by urea kinetic modelling (CI = 8.84 +/- 10.91.PCR). Low or reduced CI was associated in this study group with severe malnutrition status and high mortality rate. CI is suggested as a strong predictor of patient morbidity and mortality.

Creatinine↗
PubMed1994

[Carpal tunnel syndrome and amyloid tenosynovitis in patients undergoing chronic hemodialysis. Evaluation and treatment apropos of 130 cases].

Over a 12-year period (1979-1991), 130 carpal tunnel syndromes were diagnosed in 89 haemodialysed renal failure patients, representing 17% of all haemodialysed patients followed over the same period. 6% of patients had been haemodialysed for less than 5 years (mean duration of dialysis: 10.4 years). 25% of cases had a trigger finger and 21 out of 89 patients had amyloid arthropathy. No precise relationship was detected between the side of the carpal tunnel syndrome and the side of the arteriovenous fistula. In 130 cases, release of the median nerve and wide tenosynovectomy of the flexor tendons were performed under pneumatic tourniquet except in the case of a prosthetic shunt. Tenosynovial amyloid deposits were found in 84% of cases. The mean postoperative follow-up was 40 months (range: 6 to 120 months). Postoperatively, the acroparaesthesiae disappeared in 93% of cases. 79% of cases with a sensory defect obtained sensory recovery, versus 27% of cases with a motor deficit for motor recovery. In 20% of the 130 cases, decreased digital mobility was observed postoperatively due to extension of the tenosynovitis to the fingers. Four cases of recurrence were observed.

Adult↗
PubMed1994

Antilymphocyte globulins versus OKT3 as prophylactic treatment in highly sensitized renal transplant recipients.

Monoclonal antibodies were proposed as an effective prophylactic immunosuppressive treatment in highly sensitized patients (HSP). In this study we compared the results obtained in HSP treated with OKT3 or antilymphocyte globulins (ALG). From January 1989 to January 1993, 38 transplantations were performed in patients with high panel reactive antibodies (PRA > 50%). The group comprised 22 women and 16 men, mean age 45 +/- 2 (23-67) years; ten were second grafts and two were third grafts. Peak PRA was > or = 80% in 24 sensitized patients and 50-80% in 14 sensitized patients. Patients were randomly assigned to either prophylactic OKT3 (n = 15) or ALG (n = 23). Oral cyclosporin A (10 mg/kg) was started at day 8 in the OKT3 group and when the serum creatinine level decreased to 200 micromol/l in the ALG group. OKT3 was systematically withdrawn on day 10 but ALG was stopped only when total blood cyclosporin A concentration reached 150-200 ng/ml. In both groups, azathioprine (150 mg/day) and prednisolone were given. During the first months, 6/15 grafts were lost in the OKT3 group (three hyperacute rejections, one renal vein thrombosis, one steroid-resistant rejection, one death); in the ALG group 4/23 grafts were lost (one hyperacute rejection, two steroid-resistant rejections, one death). Side effects were significantly more frequent in the OKT3 group than in the ALG group. After 12 months of follow up, the graft survival was 71% (27/38) and did not significantly differ (log-rank test, NS) between the OKT3 (60%, 9/15) and the ALG group (78%, 18/23). We conclude that the use of the monoclonal antibody OKT3 as a prophylactic agent in HSP does not improve the early graft survival when compared with prophylactic ALG. Polyclonal antibodies, which react with many epitopes and are much better tolerated seem to offer a good strategy for induction therapy in this population.

Adult↗