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Biomedical subjects

Wim Van Biesen

Publications and source records attributed to Wim Van Biesen.

At least 19 recordsLinked to original sources
PubMed2007

The glomerular filtration rate in an apparently healthy population and its relation with cardiovascular mortality during 10 years.

AIMS: Moderate-to-severe chronic renal failure is an established risk factor for cardiovascular disease and mortality. However, most studies have been performed in selected populations and the impact of very small decrements of renal function on long-term cardiac morbidity and mortality has not yet been established. Also, the cut-off level of glomerular filtration rate (GFR) from which cardiovascular risk increases has not exactly been established. This study wants to address these questions. METHODS AND RESULTS: Ten year follow-up of a representative population-based cohort comprised 8913 randomly selected, apparently healthy participants. Participants were randomly drawn from Belgian voting lists. Cardiovascular risk factors were noted. Serum creatinine values were corrected to isotope dilution mass spectrometry standard, and GFR was calculated using the recently modified 'modification of diet in renal disease' equation. Participants were followed for 10 years, and cause-specific death was registered by analysis of death certificates. The probability to die from all causes or from cardiovascular causes during the 10 year follow-up period increased in each quartile of GFR, even after correction for different other comorbid conditions. CONCLUSION: Even mild renal failure is an independent risk factor for cardiovascular mortality within 10 years in an apparently healthy unselected population. This detrimental effect starts already at a relatively high GFR of 90 mL/min/1.73 m2 and remains present after correction for other established cardiovascular risk factors.

Cardiovascular Diseases↗
PubMed2006

Clamping of the dialysate outlet line in the Genius dialysis system does not alter dialysate flow or clearances.

BACKGROUND: The Genius dialysis system is advocated as a tool to perform slow extended daily dialysis (SLEDD) in patients with acute renal failure at the intensive care unit. At low blood flows however, it is sometimes problematic to maintain sufficient systemic pressure in the dialysate circuit, a problem that can be overcome by clamping the dialysate outflow line. This intervention can however decrease the flow in the dialysate circuit, and can thus potentially decrease the clearance. This article analyses the impact of this intervention on the blood and dialysate flows and on the removal of retention products. METHODS: The study was done in 20 stable chronic dialysis patients to avoid additional bias caused by changing comorbidities in ICU patients. Patients were treated by Genius, once with clamping and once without clamping, cross-over in a randomized fashion, and with 1 week interval. Flows in the dialysate and blood circuit were measured with a transsonic flow probe. Urea, creatinine, Beta 2 microglobulin and phosphate were measured in the dialysate, and in the serum before and after dialysis. RESULTS: There was no clinically significant difference in blood or dialysate flows, nor in clearance or removal of retention products during the sessions with or without clamping. CONCLUSIONS: The technique of using clamping of the dialysate outflow line in the Genius system to increase systemic pressure, when the system is used in SLEDD, is a safe technique which does not alter the clearances.

Aged↗
PubMed2006

The changing epidemiology of acute renal failure.

Different definitions of acute renal failure (ARF) abound. The existence of multiple definitions makes it difficult to determine the true epidemiological characteristics of this condition. Despite this difficulty, it has been possible to detect notable variations in the epidemiology of ARF during the past few decades. The absolute incidence of ARF has increased, while associated mortality rate has remained relatively static. Several factors have contributed to this altered epidemiology. Here, we discuss the relative contribution of these factors, which include site of disease onset (developed or developing countries, community or hospital or intensive care unit), patient age, infections (HIV, malaria, leptospirosis and hantavirus), concomitant illnesses (cardiopulmonary failure, hemato-oncological disease), and interventions (hematopoietic progenitor cell and solid organ transplantation).

Acute Kidney Injury↗
PubMed2006

Epidemiologic aspects of the Bam earthquake in Iran: the nephrologic perspective.

BACKGROUND: Acute renal failure is a serious, preventable, and potentially reversible midterm complication after mass disasters. In 2003, an earthquake struck Bam, Iran. This article studies the epidemiologic aspects of the earthquake from a nephrologic perspective. METHODS: A questionnaire was sent to the reference hospitals. The resulting database of 2,086 traumatized patients hospitalized in the first 10 days was analyzed. RESULTS: Mean age was 29.0 +/- 15.6 years. Compared with the resident population, the percentage of patients was lower among children and teenagers younger than 15 years and higher among young and middle-aged adults (P < 0.001). There was no significant difference between mean ages of patients with acute renal failure and other patients. Time under the rubble was longer for patients with acute renal failure (6.2 +/- 4.1 versus 2.1 +/- 3.9 hours; P < 0.001). These patients were hospitalized later (3.1 +/- 2.8 versus 1.5 +/- 1.7 days after the disaster; P < 0.001) and longer (16.7 +/- 12.8 versus 12.5 +/- 11.3 days; P < 0.001). Sepsis (11.6% versus 0.5%), disseminated intravascular coagulation (7.3% versus 0.3%), adult respiratory distress syndrome (9.1% versus 1.4%), fasciotomy (38.9% versus 1.9%), amputation (6.1% versus 0.5%), and death (12.7% versus 1.9%) were markedly more frequent among patients with acute renal failure (P < 0.001 for all). CONCLUSION: Hospitalized patients were mostly young and middle-aged adults. Patients with acute renal failure were entrapped longer and hospitalized later and for longer periods. Medical complications, surgical procedures, and mortality were greater in the latter group. Early extrication and quick hospitalization with appropriate multidisciplinary care are cornerstones to prevent acute renal failure and its subsequent mortality in earthquake conditions.

Acute Kidney Injury↗
PubMed2006

Peritoneal dialysis in Europe: an analysis of its rise and fall.

There is a wide variability in the utilization of peritoneal dialysis throughout Europe that cannot be explained by differences in medical factors alone. Over the last years, the utilization of peritoneal dialysis has even changed in individual countries. The main factors of this variation are not medical, but rather changes in reimbursement and other financial considerations. The overall structure of the health care in an individual country is to a large extent determining the use of a renal replacement therapy modality.

Costs and Cost Analysis↗
PubMed2006

What did we learn from animal models in peritoneal dialysis?

The development of animal models in peritoneal dialysis has led to some breakthroughs in the application of this dialysis modality in clinical practice. These breakthroughs are (1) a better understanding of the physiology and pathophysiology of solute transport and ultrafiltration mechanisms, (2) the observation and integration of the long-term structural and functional alterations of the membrane, (3) a better understanding of the biocompatibility issues involved in PD, leading to the clinical introduction of more biocompatible dialysis solutions and finally, (4) the development of colloid osmotic solutions containing polyglucose polymers for application in the long dwells. Intravital miscroscopy provides information in live animals about diverse functional parameters, such as blood flow rate, vessel diameter, permeability to macromolecules, leukocyte-endothelium interaction, capillary recruitment, and lymph vessel kinetics. Also evaluation of different parameters in a living experimental animal, allowing integration of function and structure is possible. A variety of chronic PD models have been developed, mainly to study effects of long-term peritoneal dialysate exposure on peritoneal membrane function and structure. The implementation of different blocking agents of biochemical substances in these models has elucidated many molecular biological mechanisms involved in these processes. The important roles of aquaporins, vascular endothelial growth factor, nitric oxide, advanced glycation end product formation and their receptor (RAGE) upregulation and the integrated roles of all these factors in the fibrotic alterations of the membrane as observed in patients on long-term PD have been investigated. More recently, genetically modified mice have been used as an important tool to investigate the molecular basis of peritoneal changes during dialysis and during acute peritonitis.

Animals↗
PubMed2005

The importance of standardization of creatinine in the implementation of guidelines and recommendations for CKD: implications for CKD management programmes.

BACKGROUND: In an attempt to reduce late referral and to improve the care of patients with chronic kidney disease (CKD), different organizations have issued guidelines on when to refer patients to the nephrologist. Most suggest referral of patients with a GFR below 60 ml/min/1.73 m2, and demand referral if the GFR is below 30 ml/min/1.73 m2. It is recommended to use the abbreviated MDRD equation to estimate GFR. This formula is, however, sensitive to the creatinine assay methodology. In addition, the impact of the implementation of such guidelines on the nephrology practice has never been evaluated. This study (i) identifies the true burden of CKD in a population and simulates the effects of a 100% implementation of the guidelines on the nephrology work load, and (ii) evaluates the validity of the estimated GFR using the abbreviated MDRD formula when routinely provided. METHODS: Different laboratories (both hospital and private) in our region were asked to report on all the serum creatinine values performed during the first week of December 2004. If patients had more than one determination, only the lowest serum creatinine value was retained. Patients already known to a nephrology unit were not included. GFR was calculated using the abbreviated MDRD, using the serum creatinine as reported by these laboratories, or after correction to the MDRD-standard using different published equations. RESULTS: 20,108 patients, with a mean age of 53.4+/-16.2 years, 48% females, had at least one serum creatinine determination in the observation period. According to the K/DOQI CKD classification, 20.2, 1.6 and 0.8% of females and 13.3, 1.6 and 0.6% of males were in stage 3, 4 and 5, respectively, when the abbreviated MDRD formula was used with the serum creatinine value as reported by the laboratories. Important differences in classifications were obtained when the different correction formulae for creatinine were applied. According to the current recommendations, this would lead to a mandatory referral of 1650-2400 CKD stage 4 patients per 100 000 inhabitants and a suggested referral of another 4100-15 360 CKD stage 3 patients per 100,000 inhabitants to a nephrology unit. CONCLUSION: Implementation of the current guidelines for referral of CKD patients to nephrologists would lead to an overload of the nephrology care capacities. Large differences in estimated GFRs with different corrections for serum creatinine are observed, resulting in important CKD classification differences. Standardization of serum creatinine assays is mandatory before guidelines, and especially the routine provision of the estimated GFR by the abbreviated MDRD formula, can be implemented in clinical practice.

Adult↗
PubMed2005

Efficacy of erythropoietin administration in the treatment of anemia immediately after renal transplantation.

Anemia negatively impacts cardiovascular comorbidity and hospitalization. In animals, recombinant erythropoietin (RhuEPO) leads to faster recovery after acute tubular necrosis. This study evaluates the effect of RhuEPO (Recormon, Hoffman-La Roche, Basel, Switzerland) on the correction of anemia and kidney function after renal transplantation. Patients receiving a renal transplant were randomized to receive or not receive RhuEPO 100 U/kg three times per week if the hemoglobin (Hb) level was less than 12.5 g/dL. The time to reach an Hb level greater than 12.5 g/dL was 66.5+/-14.5 days versus 52.6+/-23.7 days in the non-EPO and EPO groups, respectively (P=0.05). After 3 months, Hb levels were not different between the non-EPO and EPO groups (12.6+/-1.5 g/dL vs. 12.0+/-1.5 g/dL, respectively), although there was a higher increase in the EPO group (4.1+/-1.1 g/dL vs. 3.2+/-1.1 g/dL, P=0.02). In a Cox regression analysis, EPO use (relative risk 7.2, P=0.004) and dose (relative risk=0.63, P=0.04) were retained as independent variables predicting the time to reach an Hb level greater than 12.5 g/dL. In the EPO group, 14 of 22 patients reached the target Hb level of more than 12.5 g/dL versus 12 of 18 patients in the non-EPO group (P=not significant). Serum creatinine levels were not different between groups. RhuEPO in the immediate posttransplantation period seems to have no relevant clinical impact on the correction of anemia. There was no difference in the evolution of serum creatinine levels. In view of the cost, the use of RhuEpo in the posttransplantation period should be limited to high-risk patients.

Anemia↗
PubMed2005

Genetic and clinical factors influence the baseline permeability of the peritoneal membrane.

BACKGROUND: Patients starting peritoneal dialysis (PD) show a significant variability in small solute transport across the peritoneal membrane (PM). The latter parameter determines dialysis prescription and survival. Clinical factors probably influence solute transport across the PM, but the putative role of genetic variants is unknown. METHODS: We have investigated the influence of functional polymorphisms of VEGF, ENOS, and IL-6, together with clinical and biological factors, on baseline peritoneal equilibration test (PET) parameters in a homogeneous population of 152 unrelated Caucasian PD patients from Belgium and the North of France. RESULTS: The distribution of the 21 alleles (7 polymorphisms) and linkage disequilibrium parameters were similar in PD patients and healthy subjects. Univariate and multivariate analyses identified comorbidity, serum albumin, and the -174G/C polymorphism of IL-6 as independent predictors of small solute transport. The -174G/C polymorphism of IL-6 was associated with significantly higher IL-6 mRNA levels in the PM and higher plasma and dialysate IL-6 concentrations, suggesting a dominant effect of the C allele. Patients harboring the CC and GC genotypes (N= 92) were characterized by significantly higher permeability parameters and inflammatory markers than patients harboring the GG genotype (N= 60). In contrast with IL-6, VEGF and ENOS polymorphisms had no influence on baseline peritoneal permeability. CONCLUSION: These data (1) show that, together with clinical parameters, the functionally relevant -174G/C polymorphism of IL-6 contributes to the interpatient variability in small solute transport rate at the start of PD; and (2) substantiate the critical role played by IL-6 in the PM.

Adult↗
PubMed2005

Chronic kidney disease: a European perspective.

There is an exponential growth worldwide of patients with end-stage renal disease (ESRD). Prevalences, outcomes, and underlying causes of ESRD are relatively well documented through different organizations. It is, however, clear that a large part of the bad outcome of ESRD patients is due to deficient follow-up during the earlier chronic kidney disease (CKD) stages. Data on CKD, prevalence of the different stages, and the evolution to ESRD are rather scant, and available data are conflictive. This is at least partly due to the lack of an international standard for measurement of renal function. In addition, there is compiling evidence that presence of proteinuria, even with a normal renal function, predisposes to ESRD. Most authors now prefer the term "kidney injury" rather than "kidney failure" to indicate people at risk for evolution to ESRD or for complications of CKD. Detection of these patients at risk is important to implement measures to slow down progression of CKD and avoid secondary complications. As it is clear that most of these CKD patients die before they reach ESRD, it might be that by taking the necessary preventive measures, the number of ESRD patients might still further increase exponentially.

Adult↗
PubMed2005

Survival and complications of indwelling venous catheters for permanent use in hemodialysis patients.

BACKGROUND: The risk factors influencing the survival of indwelling central vein catheters and their potential complications have not been assessed in depth and on a large scale. METHODS: We investigated the general characteristics of 245 single lumen cuffed tunneled catheters and analyzed their survival by Kaplan-Meier and Cox regression analysis. Risk factors for bacteremia and thrombosis were assessed by logistic regression analysis. RESULTS: The incidence of exit-site infection, tunnel infection, bacteremia and thrombotic events was 0.35, 0.25, 1.71, and 1.94/1000 catheter days, respectively. The mean survival time per catheter was 276 days. After censoring for non catheter-related events leading to the removal of the catheter (n = 245 with 120 catheters censored and 125 events), the mean survival time of the catheter appeared to be 615 +/- 67 days (95% CI of 483-747) and the median survival time 310 +/- 50 days (95% CI of 212-408). The localization of the catheter into the right internal jugular vein results in significantly better survival as compared with other insertion sites both in Kaplan-Meier (mean survival of 650 days compared to a mean survival of 519 days, P value < 0.009) and in Cox regression analysis (relative risk of 0.537, P value < 0.001). Localization of the catheter into the right internal jugular vein seemed to increase the risk for bacteremia (relative risk of 1.798, P value of 0.063). The use of anticoagulant agents was not protective for thrombosis, although this might be due to lack of power (relative risk of 0.626, P value of 0.141). CONCLUSION: We provide evidence of a mean survival in long-term hemodialysis catheter close to 2 years with an acceptable complication rate. If a long-term hemodialysis catheter is required, it is best placed in the right internal jugular vein.

Catheters, Indwelling↗
PubMed2005

Improving salt balance in peritoneal dialysis patients.

Volume homeostasis is an important predictor of outcome in peritoneal dialysis. Because volume retention is driven by salt retention, maintenance of salt balance should be a concern to all nephrologists. An important factor in this is dietary salt restriction. This has long been neglected in peritoneal dialysis patients, where it was considered that the continuous nature of the therapy and residual renal function would be sufficient to remove any extra salt load. In patients with preserved renal function, diuresis and salt excretion can be enhanced by the application of high doses of loop diuretics. This practice seems not to have an impact on the further deterioration of renal function. Peritoneal salt removal can be enhanced using polyglucose. Also, the use of low sodium-containing dialysate can be efficient. These solutions are, however, not commercially available, and they need higher concentrations of glucose to obtain an efficient osmolarity. It should always be considered that, due to sodium sieving over the ultrasmall pores, fluid and salt removal are not always concordant.

Diet, Sodium-Restricted↗
PubMed2004

Clinical characteristics of patients developing ARF due to sepsis/systemic inflammatory response syndrome: results of a prospective study.

BACKGROUND: Acute renal failure (ARF) in patients with sepsis provokes high mortality and financial cost. In this prospective study, we collected characteristics of patients in the intensive care unit (ICU) who developed sepsis/systemic inflammatory response syndrome (SIRS) to analyze differences between those who subsequently did or did not develop ARF. METHODS: All patients admitted to the ICU of the University Hospital Gent, Belgium, between January 1, 2001, and December 31, 2001, who developed sepsis/SIRS were included if they had a serum creatinine level less than 2 mg/dL (<177 micromol/L). RESULTS: Of 2,442 patients admitted to the ICU, 257 patients developed sepsis/SIRS. Of those, 29 patients (11%) developed ARF. In a univariate analysis, age, central venous pressure (CVP), and serum creatinine and blood urea nitrogen levels were greater (P = 0.003, P = 0.006, P < 0.001, and P < 0.001, respectively), whereas mean arterial and diastolic blood pressures, 24-hour urinary output, arterial pH, bicarbonate level, thrombocyte count, albumin level, and prothrombin time were lower (P = 0.05, P = 0.004, P = 0.005, P = 0.03, P = 0.009, P = 0.037, P = 0.05, and P = 0.006, respectively) in the ARF group. Prevalence of diabetes, sex, and need for ventilation were not different between the ARF and no-ARF groups, but in the ARF group, diuretic use, vasopressor use, and presence of primary hepatic failure were more prevalent (P = 0.001 for each). In a multivariate analysis, age, serum creatinine level, CVP, and presence of liver failure significantly contributed to a logistic regression model for ARF. CONCLUSION: Several parameters already were disturbed at the first day of SIRS/sepsis in patients who later developed ARF. Older age, elevated serum creatinine level despite elevated CVP, and presence of hepatic failure are predictive for ARF in septic patients.

Acute Kidney Injury↗