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C Chazot

Publications and source records attributed to C Chazot.

At least 37 records · Page 2Linked to original sources
PubMed1998

Is post-dialysis urea rebound significant with long slow hemodialysis?

BACKGROUND: According to previous studies, postdialysis urea rebound (PDUR) is achieved within 30-90 min, leading to an overestimation of Kt/V of between 15 and 40% in 3- to 5-hour dialysis. The purpose of the study was to assess the impact of PDUR on the urea reduction ratio (URR), Kt/V and normal protein catabolic rate (nPCR) with long 8-hour slow hemodialysis. METHODS: This study was performed in 18 patients (13 males/5 females), 62.5 +/- 11.7 years of age, hemodialyzed for 3-265 months. Initial nephropathies were: 3 diabetes; 2 polycystic kidney disease; 3 interstitial nephritis; 2 nephrosclerosis; 3 chronic glomerulonephritis, and 5 undetermined. Residual renal function was negligible. The dialysis sessions were performed using 1- to 1.8-m2 cellulosic dialyzers during 8 h, 3 times a week. Blood flow was 220 ml/min, dialysate flow 500 ml/min, acetate or bicarbonate buffer was used. Serial measurements of the urea concentration were obtained before dialysis, immediately after dialysis (low flow at t = 0), and at 5, 10, 20, 30, 40, 60, 90 and 120 min, and before the next session. The low-flow method was used to evaluate the access recirculation, second-generation Daugirdas formulas for Kt/V, and Watson formulas for total body water volume estimation. The difference between the expected urea generation (UG) and urea measured after dialysis (global PDUR) defines net PDUR (n-PDUR). RESULTS: The n-PDUR usually became stable after 58 +/- 25 (30-90) min. Its mean value was 17 +/- 10% of the 30-second low-flow postdialysis urea (3.9 +/- 2 mmol/l). This small postdialysis urea value and the importance of UG in comparison with shorter dialysis justify the use of n-PDUR. Ignoring n-PDUR would lead to a significant 4% overestimation (p < 0.001) of the URR (79 +/- 7 vs. 76 +/- 8%), 12% of Kt/V (1.9 +/- 0.4 to 1.7 +/- 0.38) and 4% of the nPCR (1.1 +/- 0.3 to 1.05 +/- 0.3). n-PDUR correlated negatively with postdialysis urea (r = 0.45 p = 0.05), positively with URR (r = 0.31 p = 0.01) and Kt/V (r = 0.3 p = 0.03) but not with K, and negatively with the urea distribution volume (r = 0.33 p = 0.05). Mean total recirculation, ultrafiltration rate, predialysis urea levels and urea clearance did not correlate with n-PDUR. CONCLUSION: We found a significant PDUR in long-slow hemodialysis after a mean of 1 h after dialysis. This PDUR has a less important impact upon dialysis delivery estimation than short 3- to 5-hour hemodialysis, especially for the lower Kt/V or URR ranges. This is explained by the low-flux, high-efficiency, and long-term dialysis. Its inter-individual variability incites us to calculate PDUR on an individual basis.

Aged↗
PubMed1997

Dialytic nutrition: provision of amino acids in dialysate during hemodialysis.

Maintenance hemodialysis (MHD) patients are frequently malnourished, a condition associated with high morbidity and mortality. Amino acid (AA) losses in dialysate may enhance protein malnutrition in patients with low food intake. We studied the possibility of providing AA in dialysate during MHD to either prevent AA losses or as a nutritional supplement. Six clinically stable men were studied during three hemodialysis treatments. The first treatment was performed using the usual dialysate (0XAA). The two other treatments were performed using a dialysate containing an amount of AA equal to normal plasma AA concentrations (1XAA) or to three times the normal plasma AA concentrations (3XAA). During the OXAA treatment, the total AA losses were 10.0 +/- 0.9 (SEM) grams (g) and the total AA concentrations in plasma decreased by 49 +/- 4%. During the 1XAA treatment, the total AA balance was +0.8 +/- 1.8 g and there was no significant change in the postdialysis plasma total AA. With the 3XAA treatment, the patients gained 36.9 +/- 4.1 g of AA during the hemodialysis treatment and the plasma total AA levels increased by 45 +/- 9%. No side effects were observed. These findings indicate that it may be feasible to provide AA supplements to MHD patients by adding AA to hemodialysate.

Adult↗
PubMed1997

Central venous catheters for haemodialysis: looking for optimal blood flow.

Central venous catheters are commonly used for haemodialysis patients and represent, in our centre, about 15% of the permanent vascular accesses with a total number of more than 230 central venous catheters over the last 10 years. Inadequate blood flow may occur and upsets the nurses, the patients, and the nephrologist. The aim of this study was to identify the factors of the catheter dysfunction. We studied prospectively 25 chronic haemodialysed patients with central venous catheters, 14 women and 11 men, 65 +/- 16 (55-89) years of age, treated with haemodialysis for 6.7 +/- 7 (1-26) years. Catheters were tunnelled silicone twin catheters (Permcath Quinton n = 18, Twincath Hemotec n = 7) in right (n = 19) and left internal jugular (n = 6) inserted by percutaneous Seldinger techniques. We studied the localization of the catheter tip (superior vena cava, right atrium, right ventricular, inferior vena cava), the central venous pressure before and after haemodialysis, the blood pressure (BP) before and after haemodialysis, the interdialytic weight gain, the number of symptomatic hypotensions during the 10 last dialyses. The patients were divided into two groups: group I with usual adequate catheter function (n = 18) and group II with frequent dysfunctions (n = 7). Central venous pressure before dialysis was significantly higher in group I with adequate blood flow and the catheter's tip was more frequently found localized in the right cardiac cavities than in the vena cava. When central venous pressure before dialysis was over 5 mmHg, no dysfunction occurred. Blood pressure was not different between the two groups. We found no correlation between central venous pressure and BP, interdialytic weight gain and symptomatic hypotensions. We could not predict the central venous pressure from the mean BP but there was a higher frequency of hypotensions in the hypovolaemic patients. Optimal haemodynamic conditions will be provided by a catheter tip in the right cardiac cavities and a central venous pressure over 5 mmHg which can be provided with vascular filling or dry weight revaluation.

Aged↗
PubMed1996

Clinical assessment of dry weight.

Unsatisfactory control of blood pressure (BP) leading to an increased rate of cardiovascular events is the main cause of mortality in haemodialysis. BP control has deteriorated since haemodialysis session times have been reduced. Inadequate BP control most often is due to a failure to achieve and maintain dry weight. Dry weight and normotension have been gradually omitted in the goals of dialysis, satisfactory dialysis being reduced to an 'adequate' urea Kt/V. Ideal dry body weight needs a reappraisal. What is dry weight? How should it be clinically assessed, established and maintained in patients? The problems encountered in estimating dry weight can be solved at the bedside in most cases. The additional laboratory, echography and impedancemetry methods are research tools that hopefully can be made simpler and lower in cost so they can be used everyday at the bedside. In the mean time, with the exception of ambulatory blood pressure measurement, one must rely on careful and repeated clinical observation to determine and maintain dry weight.

Blood Pressure↗
PubMed1995

Segmental necrosis of ascending colon in haemodialysis patients.

A segmental necrosis of the ascending colon sometimes affecting the terminal ileum was observed 13 times in 12 end-stage renal disease patients over a 5400 patient-years observation period. In all but three cases the patient was operated within 24 h of onset of the abdominal pain. Three patients had a bowel perforation; nine had a limited intestinal necrosis. All underwent a partial resection or colectomy. Two died within 1 month. In all cases the mucosa was necrotic, the submucosa small vessels were congested and the mesenteric vessels were normal. Ischaemic bowel disease has been previously reported in uraemic patients, but our cases do not fit with the usual reported features of this complication. The absence of typical mesenteric infarction, vascular thrombosis, stenosis or major atherosclerotic lesions is surprising. The ascending colon topography of the lesions is very unusual. Ischaemia, constipation and other factors may play a role.

Colon↗
PubMed1995

Interdialysis blood pressure control by long haemodialysis sessions.

High blood pressure (BP) is a major factor contributing to the high incidence of cardiovascular morbidity and mortality in haemodialysis (HD) patients. According to predialysis casual BP measurements, long HD has been shown to provide good BP control. To confirm this result during the period between dialysis sessions, we performed ambulatory monitoring of BP in 91 non-selected HD patients (mean age, 58.7 (14.1) years; 14% incidence of nephrosclerosis and diabetes mellitus; treatment duration, 93.0 (77.2) months; 3 x 8 h/week, cuprophane, acetate buffer in 95% of the patients). Only one patient (1.1%) was receiving an antihypertensive medication. Ambulatory BP results were systolic (S) BP, 119.4 (19.9) mmHg; diastolic (D) BP, 70.6 (12.9) mmHg; mean (M) BP, 87.6 (13.9) mmHg. These values were significantly lower than the casual predialysis BP data and close to the reference values reported by Staessen et al. in a meta-analysis including 3476 normotensive subjects. The MBP was inversely correlated with the treatment duration, but not with interdialysis weight gain. The MBP increased significantly in the last part of the interdialysis period, and this rise was not correlated with the interdialysis weight gain. The nocturnal/diurnal ratios for SBP and DBP for the HD patients (0.97 and 0.92) were higher than the reference values reported by Staessen, (0.87 and 0.83), and argued against a nocturnal decrease in BP. We found that 52.1% of the patients had an abnormal nocturnal BP fall (MBP fall < 5%). This feature worsened during the second night of the interdialysis period.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure Monitoring, Ambulatory↗
PubMed1994

[Comparison of the functional survival in chronic renal insufficiency of Permcath jugular catheters according to their mode of insertion].

The functional survival of the same silicone double lumen catheter (DLC) was analyzed in relation with the mode of its insertion. Thirty-seven catheters were surgically inserted (34 in the right internal Jugular vein, 3 in the left internal Jugular vein), while 28 were percutaneously inserted (25 in the right internal Jugular vein, 3 in the left internal Jugular vein). The functional survival was calculated using Kaplan Meier method. Significant survival difference was looked for with log rank test. The maximum follow-up time was 62 months for surgically inserted DLC and 12 months for their percutaneous counterpart. There was no significant functional survival difference between the two groups at one year. At this term 86% of DLC were still in use. We conclude from our experience that the mode of insertion does not significantly modify the success rate of this type of blood access. The simplest and lightest method (i.e. percutaneous) should therefore be preferred.

Adult↗
PubMed1994

[Effect of catheter type on the functional survival of jugular access ports in chronic hemodialysis].

Silicone catheter (C) can be used in the hemodialysis setting as an alternative for the blood access. We analysed retrospectively the 3 types of the catheters used in 45 patients. 58 catheters were percutaneously inserted in the internal jugular vein (9 Bard (B)-Hickman; 17 Canaud (CD)-Vygon; 32 Permcath (PC)-Quinton). The indications were thrombosis or dysfunction of an arterio-venous fistula (A-V F) (52%), absence of a A-V F (21%), Thomas' shunt infection (8%), infection or extrusion of a previous catheter (19%). The functional survival curve of the C shows the best results for the PC and the worse with the B (Log-Rank test = 6,602, p < 0.037). The main cause of failure was the catheter's extrusion (3 of the 5 failures for the B; 4 of the 6 for the CD). None of the PC was extruded. Infection and inadequate blood flow were equally found in the 3 groups. In our experience, PC give the best results because of the quality of the cuff making a good attachment in the sub-cutaneous tunnel.

Aged↗
PubMed1994

[Temporary vascular access for extra-renal detoxification: utilization of tunneled silicone double-lumen catheters by the percutaneous route].

Femoral or subclavian central venous catheters are commonly used for temporary vascular access in haemodialysis. We used 36 tunnelized siliconed double lumen catheter (Quinton Permcath or Hickman Bard), most of them in right internal jugular percutaneously. Indication for this catheter were acute or chronic renal failure, plasma exchange, rescue of arterio venous fistula or peritoneal dialysis. Insertion incidents were minors (local haematoma), mean functional time was 51 days. Catheters were changed in 5 cases of infection, 3 cases of obstruction and in 2 accidental remove. Insertion facility, low morbidity, potentially long time use, high blood flow rate with low recirculation argue for this expensive material.

Adult↗
PubMed1993

Functional study of hands among patients dialysed for more than 10 years.

Sixty-six haemodialysed (HD) in centre patients (24 h/m2/week, acetate bath, cuprophane membrane), with a mean age of 59.2 years, treated for 16.7 +/- 4.5 years, underwent clinical examination of their hands to determine anatomical and functional alterations. For each hand a functional score was calculated from a medicolegal technique based on sensitivity and angulation amplitude (rating from 0 to 100). Dialysis-related arthropathy (DRA), including carpal-tunnel (CT) syndrome, was scored as well as hand muscle amyotrophia. Trigger fingers, abnormal synovial hypertrophy, and one or more non-functional tendons were found in 15, 26, and 33% of the patients respectively. Thirteen percent had pseudoporphyria. Amyotrophy was moderate or severe in 39%. The global functional score (mean of the two unilateral functional scores) decreased with time spent on haemodialysis and was correlated with the DRA score. The unilateral functional score was linked to tendinous lesions, amyotrophy, and presence of pulses, but not to CT surgery or presence of AV fistula. Hands with ulnar insult at the elbow shown by electromyography had significantly lower functional scores. Repercussions of hand functional alteration may have an important social and psychological impact in daily life. The responsibility of amyloidosis is evidenced by tendinous lesions and nervous entrapment. Ulnar palsy is also important because of the vital motor role of that nerve in hand function.

Aged↗
PubMed1992

Pulmonary hemorrhage and glomerulonephritis in primary biliary cirrhosis.

We observed life-threatening intrapulmonary hemorrhages and focal proliferative glomerulonephritis in a 41-yr-old woman with primary biliary cirrhosis. The severity of the symptoms necessitated blood transfusions and mechanical ventilation; the patient improved with the help of corticosteroid therapy. No formal evidence of either Goodpasture's syndrome or any other well-defined systemic vasculitis could be found. Neutrophil cytoplasmic antibodies were initially positive and became undetectable after 3 mo of immunosuppressive treatment without relapse. This association has not been described previously and may be added to the list of extrahepatic immune-mediated conditions associated with primary biliary cirrhosis.

Adult↗
PubMed1992

Survival as an index of adequacy of dialysis.

To examine how patient survival substantiates dialysis adequacy, 20-year actuarial survival experience was calculated for 445 unselected hemodialysis (HD) patients (97 patients accepted on a temporary basis--and usually kept on their regular dialysis scheme--were left out). The dose of dialysis has been the same and unchanged for all patients since beginning: 24 square meter hours of Kiil dialysis (cuprophane) per week with acetate buffered dialysate. KT/V mean (SD) was 1.67 (0.41). Six months after starting dialysis, 98% of patients were normotensive and off all blood pressure (BP) medication. The mean population hematocrit, excluding the only 6 patients receiving erythropoietin supplementation, was 28%. Survival rate was 87% at 5 years, 75% at 10 years, 55% at 15 years, and 43% at 20 years of HD. The satisfactory control of BP without using potentially toxic BP drugs and the higher than usual dose of dialysis are two possible explanations for survival data better than usually reported. We suggest that patient survival should be considered as the best overall index of adequacy of dialysis.

Adult↗
PubMed1992

Dose of dialysis: what index?

Wider patient acceptance criteria in hemodialysis (HD) programs do not seem to completely explain the increasing mortality reported in the United States at a time characterized by reduced treatment time and dose. This raises the question of HD standard and adequacy. It stimulated us to analyze patient survival with unchanged 'old-times' methods. 445 unselected patients have been treated for 22 years by the same unchanged methods (24 m2/week, flat-plate dialyzers, cuprophane membrane, acetate buffer). Their survival data were compared to major HD registries and series. Survival was also evaluated as a function of mean arterial pressure (MAP), urea fractional clearance (Kt/V), and middle-molecule dialysis index (DI). Kaplan-Meier (with log-rank test) analysis and Cox proportional hazard model were used. Survival at short and long term was better in our series. This favorable survival difference was more obvious for older patients at the start of HD. It could not be accounted for by selection bias, but correlated with good MAP control without medication and with higher than usual Kt/V (1.67 +/- 0.41) and DI (1.47 +/- 0.38). Cox analysis including five covariates confirmed that survival was linked to MAP. It suggested that survival improvement might be expected from a DI increment of over 1.38 but not from a Kt/V increment of over 1.60. Adequate dialysis cannot be reduced to numbers; it should include both sufficient small- and middle-molecule diffusion and ultrafiltration with arterial pressure control without need for antihypertensive medication. The long-term satisfactory survival remains the best index of overall dialysis adequacy.

Adult↗