Hélène Leray

Association between novel indices of malnutrition–inflammation complex syndrome and cardiovascular disease in hemodialysis patients

Background:  Inflammation and malnutrition are recognized as important risk factors for cardiovascular disease (CVD) in hemodialysis (HD) patients. Owing to substantial short‐term variability of serum C‐reactive protein (CRP), more reliable markers of malnutrition–inflammation complex syndrome should be sought with stronger associations with the risk of CVD in HD patients. We therefore explored the clinical relevance of a composite inflammatory index (prognostic inflammatory and nutritional index [PINI]) and of muscle protein mass indicators, derived from creatinine kinetics.

Optimal Therapeutic Conditions for Online Hemodiafiltration

The safety of online hemodiafiltration (ol-HDF) relies on very strict rules of use. The use of ultrapure water to feed an ol-HDF machine is a basic requirement for ol-HDF. Technical aspects and microbial monitoring have been precisely described in the European Best Practice Guidelines. Specifically designed and certified ol-HDF machines are needed. All these machines share the production of substitution fluid by the cold sterilization process of fresh dialysate based on ultrafilters. Hygiene handling is a crucial measure to ensure permanent safety of the ol-HDF system. Frequent disinfection of the water treatment system and dialysis machine, destruction of biofilm by chemical agents and/or thermochemical disinfection, change of filters at regular intervals, and maintenance of a permanent circulation of water are among the basic measures required to ensure ultra-purity of water and dialysis fluid. Optimal performances of ol-HDF require the use of high blood flow (300-400 ml/min), highly permeable and adequately sized hemodiafilters, a high volume of substitution (5-6 l/h) and high dialysate flow (500 ml/min). The site and type of substitution (pre-, post-, mixed, and mid-dilution) should be customized to each patient according to its blood hemorheology and its filtration fraction limitation (transmembrane pressure). All attempts should be made to maximize the fluid volume exchange per session (convective dose) in any cases. The treatment schedule in terms of session duration and weekly frequency need to be adjusted individually to improve hemodynamic tolerance, to facilitate correction of fluid overload and to increase dialysis dose (for middle-sized solutes) in order to reduce circulating levels of major uremic toxins. ol-HDF is the more advanced form of renal replacement therapy offering high efficiency over a large spectrum of toxins, high biocompatibility profile and high flexible modality. ol-HDF may help to improve global care of chronic kidney disease patients and may be considered the renal replacement therapy of the future.

Cross-membrane flux is a major factor influencing dialysis patient outcomes.

Conventional diffusive-based dialysis modalities including high-flux hemodialysis are limited in their capacity to clear middle and large size uremic toxins. Middle molecule substances are recognized as pathogenic substances implicated in the genesis of accelerated atherosclerosis. Convective methods, mimicking glomeruli filtration of native kidneys, are required to enlarge the molecular weight spectrum of solutes removed. By combining diffusive and convective solute clearances, HDF offers at the present time the highest dialysis efficiency method with the more biocompatible profile. Instantaneous dialyzer clearance does not reflect solute mass removal when body clearance is concerned. Intracorporeal resistance to solute clearance is the main barrier to solute removal. Increasing treatment time and/or frequency of sessions in hemodiafiltration is the only way to overcome body barriers generated from patient/dialysis interaction. A dialysis dose based on normalized middle molecules clearance using Beta2-microglobulin as surrogate marker should be considered as a new adequacy target.

Optimal management of central venous catheters for hemodialysis.

Good medical practices for optimizing the management of central venous catheters (CVCs) can be summarized in the following ten commandments: (1) the indications of CVC use you will restrict; (2) the choice of the catheter type and site venous you will discuss; (3) an experienced operator you will choose; (4) validated protocols of use and maintenance of catheters you will respect; (5) caring and nursing staff of the dialysis unit you will train and control; (6) the patients you will educate; (7) monitoring and maintenance care of CVC you will apply; (8) the duration of CVC use you will restrict; (9) specific patient risk factors you will evaluate and correct, and (10) a continuous quality improvement care process for CVC you will establish and apply in your dialysis unit.

Biomarkers of cardiorenal syndrome

Complex interactions existing between cardiac and renal diseases led to define 5 types of so-called cardiorenal syndromes. This classification is based on the organ primarily involved and the acute or chronic failure. The mutual impact of renal and cardiac functions makes it difficult to evaluate and manage patients with cardiorenal syndromes and worsen morbidity and mortality. This review seeks to discuss the place of biomarkers in diagnosis, management and follow-up of patients with cardiorenal syndromes. Biomarkers can be classified as functional (creatinine, cystatin C…) or lesional (neutrophil gelatinase-associated lipocalin, urinary cystatin C…) renal markers and functional (natriuretic peptides…) or lesional (troponin, fatty acid binding protein) cardiac markers. A last kind of biomarkers reflects the dialogue between heart and kidney (renin-angiotensin-aldosteron-system, indicators of activation of arginine vasopressin system) or the systemic impact (inflammation, oxidative stress…). In order to evaluate accurately the complex interactions that are the basis of cardiorenal syndromes, a multi-marker approach seems nowadays necessary.

L’âge et la fonction rénale sont-ils des limites à l’interprétation des biomarqueurs cardiaques ?

New highly sensitive (hs) assays have challenged the interpretation of cardiac troponins (cTn) as markers of injury while natriuretic peptides remain the markers of choice for myocardial dysfunction. However, variability extracardiac factors such as age, gender and renal function may alter circulating levels. In chronic kidney disease (CKD), the increase in circulating levels of these biomarkers in the absence of cardiac disease underlines the problem of discriminative value for diagnosis as well as the need to redefine the thresholds. In addition, these biomarkers are of potential interest to stratify cardiovascular risk, the leading cause of death in CKD. The aim of this work is to clarify the effect of age and renal function on circulating levels of high-sensitivity troponins and natriuretic peptides.