PubMed Health⌕ Search

Biomedical subjects

Charles Chazot

Publications and source records attributed to Charles Chazot.

9 recordsLinked to original sources
PubMed2006

Stability of nutritional parameters during a 5-year follow-up in patients treated with sequential long-hour hemodialysis.

Progressive nutritional impairment has been recently reported during conventional hemodialysis (HD) treatment. We studied the nutritional parameters during a 5-year follow-up in HD patients. Thirty-three patients (15F/18M; 65 years old at the study start) filled out a 3-day food questionnaire once a year between 1995 and 1999 (study group). Twenty patients, who did not fill out the food records during this period served as a control group (control group). The food record was run by the renal dietician using a dedicated software, providing daily energy and protein intakes (DEI and DPI). Serum albumin, normalized protein equivalent of nitrogen appearance (nPNA), and postdialysis body weight (BW) at the time of food record were collected in the study group and from the patient chart in the control group. The energy intake in the study group and the protein intake in both groups were close to the recommended intakes in ESRD patients. Protein intake assessed from food questionnaire or from urea kinetics were not statistically different. Using ANOVA for repeated measures, no difference along the 5 years was found for daily energy intake, daily protein intake, nPNA, and BW in the study group. The BW and nPNA remained stable in the control group. Hence, this study does not confirm the progressive nutritional impairment reported in the HEMO study, whereas the patients' age and vintage are largely higher in the present study. The role of a large dialysis dose in maintaining nutritional status in HD patients is discussed.

Aged↗
PubMed2004

Hypertension and cardiovascular risk assessment in dialysis patients.

INTRODUCTION: Cardiovascular (CV) disease is the main cause of morbidity and mortality in dialysis patients. Hypertension in patients affected by chronic renal insufficiency (CRI) has been recognized as one of the major classical CV risk factors in CRI from the very beginning of the dialysis era. However, its treatment is still unsatisfactory. METHODS: A discussion is employed to achieve a consensus on key points relating to the epidemiological, pathophysiological and clinical characteristics of hypertension in renal patients, in the light of global CV risk assessment. RESULTS: CV disease is accelerated by CRI, in particular by uraemia-specific risk factors. This is reflected by the fact that general population-based equations for calculating CV risk underestimate the real CV risk in CRI and dialysis patients. Hypertension in dialysis patients is clearly a major CV risk factor. Isolated systolic hypertension with increased pulse pressure is the most prevalent blood pressure (BP) anomaly in dialysis patients, due to stiffening of the arterial tree. BP should be assessed by clinical measurements on a routine basis, leaving 24 h monitoring for selected cases. The targets of BP control should be those recommended by the present guidelines, i.e. <140/90 mmHg, or the lowest possible values that are well tolerated. The pathophysiological cornerstone of hypertension in dialysis patients is extra-cellular volume expansion, which is typically sodium-sensitive, given the loss of renal function. Therefore, the principles of hypertension treatment in dialysis are an achievement of dry body weight, proper dialysis prescription with respect to dialysis time and intra-dialytic sodium balance, and dietary sodium and water restriction. Pharmacological treatment should only be the second option, after the adequate and complete application of all other means. No comparative pharmacological trials have specifically addressed the issue of hypertension control in dialysis patients. Therefore, this workshop group had to rely largely on data obtained in the general population. Drugs interfering with the renin-angiotensin system were felt to be the first choice, as they have widely been shown to interfere significantly with CV remodelling. Despite long-standing concerns, beta-blockers are being used increasingly even in patients with congestive heart failure and ischaemic cardiomyopathy. Other drug classes may be used in association or as first-line agents according to clinical requirements. CONCLUSIONS: Hypertension in renal patients has to be given particular and continued attention, and it should be adequately treated in light of the increased CV risk of this patient population. Research into the mechanisms of uraemic cardiomyopathy and cardiovascular remodelling should provide a precious new insight and lead to more precisely targeted and more effective therapies than in the past.

Blood Pressure↗
PubMed2004

Optimal composition of the dialysate, with emphasis on its influence on blood pressure.

UNLABELLED: Introduction. From the beginning of the dialysis era, the most appropriate composition of the dialysate has been one of the central topics in the delivery of dialysis treatment. METHODS: A discussion is employed to achieve a consensus on key points relating to the composition of the dialysate, focusing on the relationships with blood pressure behaviour. RESULTS: Sodium balance is the cornerstone of intra-dialysis cardiovascular stability and good inter-dialysis blood pressure control. Hypernatric dialysis carries the risk of positive sodium balance, with the consequent possibility of the worsening sense of thirst and hypertension. Conversely, hyponatric dialysis may lead to negative sodium balance, with the possibility of intra-dialysis cardiovascular instability and 'disequilibrium' symptoms including fatigue, muscle cramps and headache. The goal is to remove with dialysis the exact amount of sodium that has accumulated in the inter-dialysis interval. The conductivity kinetic model is applicable on-line at each dialysis session and has been proved to be able to improve intra-dialytic cardiovascular stability in hypotension-prone patients. Therefore, it should be regarded as a promising tool to be implemented in everyday clinical practice. Serum potassium concentration and variations during dialysis treatment certainly play a role in the genesis of cardiac arrhythmia. Potassium profiling, with a constant gradient between plasma and dialysate, should be implemented in clinical practice to minimize the arrhythmogenic potential of dialysis. Calcium plays a role both in myocardial contractility and in peripheral vascular resistance. Therefore, an increase in dialysate calcium concentration may be useful in cardiac compromised hypotension-prone patients. Acid-buffering by means of base supplementation is one of the major roles of dialysis. Bicarbonate concentration in the dialysate should be personalized in order to reach a midweek pre-dialysis serum bicarbonate concentration of 22 mmol/l. The role of convective dialysis techniques in cardiovascular stability is still under debate. It has been demonstrated that dialysate temperature and sodium balance play a role and this should be taken into account. Whether removal of vasoactive, middle-sized compounds by convection plays an independent role in improving cardiovascular stability is still uncertain. CONCLUSIONS: The prescription of dialysis fluid is moving from a pre-fixed, standard dialysate solution to individualization of electrolyte and buffer composition, not only during the dialysis session, but also within the same session (profiling) in order to provide patients with an optimal blood purification coupled with a high degree of tolerability.

Acid-Base Equilibrium↗
PubMed2004

[Nutrition and dialysis: how to keep adequate nutrition in dialysis?].

Malnutrition is frequent in dialysis patients and it increases the mortality risk in this setting. There are many causes of malnutrition including protein metabolism impairment, amino acid and nutrient losses in dialysate, dialysis-induced muscle catabolism, metabolic acidosis, increased energy expenditure, resistance to anabolic hormones, comorbidities, oxidant stress and inflammation whose mechanisms are not identified well. Inflammation and malnutrition are associated with vascular complications frequently observed in dialysis patients. Daily nutrient needs have been established from nitrogen balance studies. The recommended intakes are 1,2 g/ kg/day for proteins, and 35 Kcal/kg/day for energy. Food intake in dialysis patients remain far below these recommendations in most of the studies, mainly because of anorexia caused by inflammation and the uremic state. Dialysis dose or frequency increase food intake. Evaluation of the nutritional status relies on biological parameters and anthropometrics, with food intake records. Nutritional scores, established from these data, are well correlated with patient outcomes. Malnutrition treatment includes counselling, and suppression of all inflammation sources. Appetite stimulants have been seldom used in this setting. Oral supplements may be efficient Intradialytic parenteral nutrition in hemodialysis patients and amino acid-enriched dialysate in peritoneal dialysis improve nutritional parameters of malnourished patients but their efficiency to improve patient survival is questioned. Adequate nutrition is an important challenge for dialysis patient outcome. Nutritional status must be regularly assessed and treated if necessary. Close collaboration between dialysis and dietetic staffs remains essential to handle this challenge.

Humans↗
PubMed2003

Volume control, blood pressure and cardiovascular function. Lessons from hemodialysis treatment.

The balance of sodium, through its dietary intake and renal excretion, determines extracellular fluid volume (ECV). Chronic renal failure and dialysis patients present with a positive sodium balance and increased ECV. The consequences are systemic hypertension and vascular and cardiac remodelling, especially left ventricular hypertrophy (LVH). High blood pressure (BP) and LVH increase the mortality risk of dialysis patients. Correction of ECV overload with ultrafiltration has led to the dry weight concept, which is the postdialysis body weight that allows BP to remain normal until the next dialysis session, without the need for antihypertensive medication and despite interdialytic weight gain. Blood pressure is the key indicator of ECV and is used to set the body weight target at each dialysis session. Normalization of BP indicates normalization of ECV, usually with a lag-time. Shortening dialysis time, which increases intradialytic morbidity, compromises the achievement of dry weight and normalization of ECV. Such intradialytic events may also lead to an increase in dialysate sodium concentration, which causes thirst, and greater interdialytic weight gain, positive sodium balance and worsening BP. These complications have led to the development of other tools for ECV assessment, such as inferior vena cava diameter, bioimpedance, and blood volume monitoring; their usefulness is discussed.

Animals↗
PubMedDate not supplied

Long 3 x 8 hr dialysis: a three-decade summary.

A long hemodialysis (HD), 3 x 8 hours/week, has been used without significant modification in Tassin for 35 years with excellent morbidity and mortality results. It can be performed during the day or overnight. The relatively good survival is mainly due to a lower cardiovascular mortality than usually reported in dialysis patients. This in turn is mainly due to the good control of blood pressure (BP) including drug-free hypertension control and low incidence of intradialytic hypotension. This control of BP is probably the result of the tight extracellular volume normalization (dry weight), although one cannot exclude the effect of other factors such as serum phosphorus control well achieved using long dialysis. The high dose of small and even more of middle molecules is another essential virtue of long dialysis, leading to good nutrition, correction of anemia, control of serum phosphate and potassium with low doses of medications and providing a very cost-effective treatment. In 2002 one must aim at optimal rather than just adequate dialysis. Optimal dialysis needs to correct as perfectly as possible each and every abnormality due to renal failure. It can be achieved using longer (or more frequent) sessions. Overnight dialysis is the most logical way of implementing long HD with the lowest possible hindrance on patient's life. Due to the change in case mix a decreasing number of patients are able or willing to go on overnight dialysis, education to be autonomous is more difficult, but the benefit is still there.

Adult↗