Search PubMed⌕ Search

Biomedical subjects

Raymond Vanholder

Publications and source records attributed to Raymond Vanholder.

89 records · Page 5Linked to original sources
PubMed2002

The role of trace elements in uraemic toxicity.

Although most research on uraemic toxicity has focused on the retention or removal of organic solutes, subtle changes in the concentration of inorganic compounds are also of importance because these compounds may have significant clinical consequences. Potential clinical implications include increased risk of cancer, cardiovascular disease, immune deficiency, anaemia, renal function impairment and bone disease. In uraemic patients, the most important factor affecting trace element concentration is the degree of renal failure and modality of renal replacement therapy. Accumulation of trace elements in haemodialysis patients has resulted from dialysate contaminated with aluminium and strontium. Several trace elements have been implicated in the decline of renal function. These include arsenic, cadmium, copper, germanium, lead and mercury. In uraemic patients, aluminium, cadmium, chromium, lanthanum, strontium and zinc have been shown to accumulate in bone. In addition to substantial evidence linking aluminium to renal osteodystrophy, studies have also implicated cadmium, iron and strontium in bone disease. Studies using a rat model of chronic renal failure have demonstrated an association between lanthanum accumulation and mineralization defects characteristic of osteomalacia. Investigations of arsenic accumulation in animal models have demonstrated that speciation of trace elements potentially may alter toxicities of trace elements accumulated in uraemic patients. Conversely, the presence of uraemic toxins may also alter the uptake and toxicity of certain trace elements. Although research in uraemic patients has focused primarily on total concentrations of trace elements, the evolution of both inorganic and organic species should be considered separately.

Bone and Bones↗
PubMed2002

Lessons learned from the Marmara disaster: Time period under the rubble.

OBJECTIVE: To investigate the effect of the time period under the rubble on morbidity and mortality of the crush-syndrome patients after the catastrophic Marmara earthquake that struck northwestern Turkey in August 1999. DESIGN: Observational study. SETTING: Consecutive admissions to emergency and intensive care units of 35 reference hospitals that treated the renal victims. METHODS: Analysis of questionnaires obtained from these hospitals. PATIENTS: A total of 539 of 639 crush-syndrome patients whose time under the rubble was identified in the questionnaires. RESULTS: Mean time under the rubble was 11.7 +/- 14.3 hrs (median, 8 hrs; interquartile range, 6 hrs; range, 0.5-135 hrs). The highest number of patients was entrapped within the 5-8 hrs time stratum, and by the end of 48 hrs, 97% of the victims had been rescued. Nondialyzed victims spent a longer duration under the rubble than dialyzed ones (15.9 +/- 23.1 hrs [median, 7 hrs; interquartile range, 8.5 hrs] vs. 10.3 +/- 9.5 hrs [median, 8 hrs; interquartile range, 6 hrs), p <.001)]. Likewise, in the strata of longer time under the rubble, the percentage of survivors was higher (p =.07). Time under the rubble correlated positively with the number of amputated extremities (p <.001) and admission platelet count (p <.001), and it correlated negatively with admission serum albumin (p <.001). The victims entrapped for >50 hrs (n = 6) were characterized by lower figures of admission blood urea nitrogen (p =.04), serum creatinine (p =.003), hemodialysis sessions, and duration of hemodialysis support (p =.005, for both analyses) compared with victims whose time under the rubble was shorter. CONCLUSION: Rescue efforts should continue at least for 5 days after the disaster. Time under the rubble is not an adverse prognostic indicator of survival or renal dysfunction for the patients of crush syndrome, probably because only the victims with mild or moderate injuries can survive under the rubble for longer durations.

Adolescent↗
PubMed2002

Treatment modalities and outcome of the renal victims of the Marmara earthquake.

BACKGROUND/AIMS: Treatment of renal problems during natural catastrophes is highly complicated both for medical and logistic reasons. The therapeutic interventions applied to and the outcome of 639 victims with acute renal problems during the catastrophic Marmara earthquake have been the subject of this study. METHODS: Questionnaires regarding information about 63 clinical and laboratory variables were sent to 35 reference hospitals that treated the victims. Information considering therapeutic interventions and outcome obtained through these questionnaires was submitted to analysis. RESULTS: At least one form of renal replacement therapy was administered to 477 (74.6%) of the 639 victims. Of these, 437, 11, and 4 were treated solely by intermittent hemodialysis, continuous renal replacement therapy, and peritoneal dialysis, respectively; 25 victims needed more than one dialysis modality. In total, 5,137 hemodialysis sessions were performed. Also, 2,981, 2,837 and 2,594 units of blood, fresh frozen plasma, and human albumin were administered, respectively. Transfusion of these products was usually associated with higher rates of dialysis needs and mortality. Ninety-seven patients (15.2%) died. The mortality rate of dialyzed victims was higher as compared to nondialyzed ones (17.2 vs. 9.3%, p = 0.015). CONCLUSIONS: Massive amounts of dialysis treatment as well as blood and blood product transfusions can be necessary in the treatment of catastrophic earthquake victims with nephrological problems. Despite the potential risk of a high mortality, in the case of appropriate and energetic medical interventions, reasonable final outcomes can be achieved.

Acute Kidney Injury↗
PubMed2002

The impact of healthy start peritoneal dialysis on the evolution of residual renal function and nutrition parameters.

The optimal time to start renal replacement therapy remains controversial. Residual renal function (RRF) and nutrition status being important prognostic factors, the present study evaluates the impact of timely start of peritoneal dialysis (PD) on their evolution. Our study used a prospective database on pre-end-stage renal disease patients at a tertiary care center. We included 18 patients who were planned to start PD at a GFR > 8 mL/min between 1 January and 31 December 1999. At the start of PD (month 0), creatinine clearance (CCr) was 11.3 +/- 3.9 mL/min, actual glomerular filtration rate (GFR) was 8.6 +/- 3.3 mL/min, and Kt/V was 1.56 +/- 0.65. The monthly declines of GFR and CCr before and after the start of PD were -0.47 +/- 0.64 mL/min (GFR) and -0.59 +/- 0.46 mL/min (CCr), and -0.06 +/- 0.30 mL/min (GFR) and -0.05 +/- 0.39 mL/min (CCr) respectively (p = 0.034 and 0.001, respectively). Before the start of PD, CCr was 21.9 +/- 4.6 mL/min (month -12) and 18.1 +/- 4.8 mL/min (month -6, p < 0.001). After the start of PD, CCr was 12.0 +/- 4.3 mL/min (month 3), 11.5 +/- 4.9 mL/min (month 6), and 13.1 +/- 5.4 mL/min (month 12, p = 0.9). Serum albumin dropped until just before the start of PD: 3.89 +/- 0.59 g/dL (month -6) and 3.78 +/- 0.51 g/dL (month -3) versus 2.56 +/- 1.60 g/dL (month 0, p = 0.04). Serum albumin then increased to 3.42 +/- 0.95 mg/dL (month 3 after the start of PD) and 3.35 +/- 0.86 mg/dL (month 6 after the start of PD, p = 0.04). In the months preceding the start of PD, the normalized protein catabolic rate (nPCR) dropped from 1.41 +/- 0.36 g/kg daily (month -6) and 1.34 +/- 0.46 g/kg daily (month -3) to 1.12 +/- 0.25 g/kg daily (month 0). It then stabilized at 1.17 +/- 0.25 g/kg daily (month 3) and 1.18 +/- 0.17 g/kg daily (months 6). One patient died owing to a cerebrovascular accident after 18 months of PD, and one was transferred to hemodialysis because of ultrafiltration failure after 19 months of PD. During 264 patient-months, 14 peritonitis episodes occurred. Of the 14 episodes, 12 resolved without complication, and the catheter was replaced in 2 episodes. After timely start of PD, the rate of RRF decline decreases. Already, at a GFR > 8 mL/min, uremia has a negative impact on nutrition parameters. Timely initiation of PD could reverse the negative evolution of albumin and stop the decline of nPCR. No severe complications related to PD were seen. In view of the important impact of RRF and nutrition on patient outcome, our data may favor an early start of PD.

Creatinine↗
PubMed2000

Rhabdomyolysis.

Explore the source record for details and available documents.

Acute Kidney Injury↗
PubMedDate not supplied

Acute renal failure.

This seminar covers the most recent information on definition, epidemiology, and clinical causes of acute renal failure. The mechanisms of acute prerenal failure and the potential interference by commonly used drugs of autoregulation of renal blood flow are discussed. We summarise some basic and recent insights into the haemodynamic and cellular pathophysiological mechanisms, mainly of postischaemic acute renal failure. Recent findings on the repair mechanisms of renal injury and the potential future therapeutic possibilities are discussed. We provide some differential diagnostic approaches for patients with acute renal failure and summarise prevention of the disorder and management of critically ill patients by dialysis and by other means. Finally, some information on the influence of gene polymorphisms on the prognosis of acute renal failure is given.

Acute Kidney Injury↗
PubMedDate not supplied

Dissociation between dialysis adequacy and Kt/V.

Since the initiation of dialysis, nephrologists have sought an index (or indices) for the adequacy of toxic solute removal. This quest has been characterized by a gradual shift in thinking, ending with a preference for dynamic parameters such as clearances normalized for body size (Kt/V). The threshold Kt/V, however, has changed over the years. While present guidelines suggest 1.2 with single-pool kinetics, higher levels might be proposed in the future. In spite of the known relation between Kt/V and survival, the accuracy of this parameter as a representative of the removal of the whole spectrum of compounds that are responsible for uremia is problematic. Kt/V only assesses the removal of a water-soluble compound from the body water through mostly hydrophilic membranes to the dialysate water. Furthermore, the small size of urea means that convective and/or diffusive transfer through a given semipermeable membrane is unlikely to be representative of larger molecules, especially if dialyzers with a small pore size are applied. Urea kinetics are also poorly representative of the removal of small protein-bound molecules and intracellular solutes with cell membrane-limited clearance. Finally, it should be realized that the Kt/V concept has been developed in a specific population, that is, a group of renal failure patients with few comorbidities, submitted to short intermittent hemodialysis with small-pore bioincompatible membranes very likely using dialysate of lower quality than that used today. Kt/V might well become less accurate and useful in predicting outcomes as different dialysis conditions are pursued, such as dialysis with biocompatible and/or large-pore membranes, (ultra) pure dialysate, alternative time frames, high levels of convection, and/or in populations with a different distribution of body mass.

Body Weight↗
PubMedDate not supplied

The dialytic management of acute renal failure in the elderly.

In this article the different dialysis strategies in the management of acute renal failure (ARF) in the elderly are discussed. Although peritoneal dialysis (PD) offers some theoretical advantages, there are several medical and technical reasons why it is currently less frequently used. The choice between intermittent hemodialysis (HD) and continuous renal replacement therapy (CRRT) is determined by a number of considerations, the most important ones being hemodynamic stability, the need for hyperalimentation and/or ultrafiltration, and the local experience with one or both techniques. Some recent studies with CRRT in elderly ARF patients describe favorable results. Slow extended daily dialysis (SLEDD) modalities may be particularly indicated in elderly, critically ill ARF patients because these techniques combine the advantages of both CRRT and HD. Finally, the importance of the biocompatibility of dialysis membranes is discussed. Although there are a number of theoretical arguments to use biocompatible membranes, this opinion is not always supported by the results of recent comparative studies. It is the opinion of the authors that all dialysis strategies should be mastered and utilized for appropriate indications in elderly ARF patients.

Acute Kidney Injury↗
PubMedDate not supplied

Peritoneal dialysis in anuric patients: concerns and cautions.

Most recent studies have found an equivalent survival for patients on peritoneal dialysis (PD) and hemodialysis (HD); evidence even suggests that PD might be the preferred modality during the first 3-4 years of renal replacement therapy. This is probably related to the continuous and minimally invasive character of PD as compared to HD, resulting in better preservation of residual renal function (RRF) and less cardiovascular strain. On the other hand, blood pressure control, fluid balance, and adequacy targets may be difficult to obtain in long-term PD patients. The question arises whether PD is a feasible option in anuric patients. It is clear that the answer depends on the body size and the peritoneal membrane transport characteristics of the patient, so that PD will be feasible in some anuric patients, whereas in others it will not be. Evaluation of the peritoneal transport characteristics and adaptation of the PD prescription is warranted. A constant evaluation of the fluid balance, nutritional, and cardiovascular status is needed. This article reviews the physiologic insights and clinical evidence necessary for a good PD prescription in anuric patients.

Anuria↗
PubMedDate not supplied

The other side of the coin: impact of toxin generation and nutrition on the uremic syndrome.

Both the morbidity of the uremic syndrome and the generation of uremic toxins are attributed to malnutrition. If protein intake and catabolism result in the generation of solutes, then nutritional intake should be related directly to toxicity. On the other hand, inadequate nutrition has been linked to inflammation and mortality. It remains difficult to reconcile these two lines of thought. Several possibilities exist that might account for this apparent paradox: 1) not all nutritional and protein degradation products are toxic; 2) toxins generated from increased protein intake are removed if protein intake is linked to dialysis dose; 3) albumin acts as a buffer for toxicity-hypoalbuminemia favors liberation of protein-bound toxins from their binding sites, enhancing their toxicity; 4) solutes generated from tissue breakdown are more toxic than those generated by nutritional protein; 5) both high and low concentrations of solutes have a negative impact; 6) toxic compounds unrelated to protein breakdown are specific causes of malnutrition and inflammation; 7) and/or residual renal function plays a key role in the elimination of compounds discussed under possibility 6. Thus the uremic syndrome should be considered as a potentially fatal interaction among inflammation, malnutrition, low levels of albumin in the plasma, accumulated protein-bound solutes and generation of nonnutritionally related toxins. Not only optimal dialysis, but also optimal nutritional intake and optimal utilization of these nutrients should help neutralize this chain of events.

Dietary Proteins↗
PubMedDate not supplied

The role of APD in the improvement of outcomes in an ESRD program.

We review the role of automated peritoneal dialysis (APD) in improving outcomes of an end-stage renal disease (ESRD) program. As the "integrated care approach" becomes accepted as the preferred strategy for treatment of ESRD patients, we looked for the potential place of APD in such an approach. APD has probably the same advantages as CAPD as a first-line renal replacement modality in suitable patients willing to perform PD. There is currently no hard evidence that residual renal function (RRF) should decline more rapidly in APD than in CAPD, at least if a dry abdomen during the day is avoided. The detection of peritonitis is probably more delayed in APD, but the frequency of peritonitis is lower, and there is no hard evidence pointing to a poorer outcome of peritonitis in APD as compared to CAPD. Quality of life is at least as good in APD, which is mostly related to the increased possibilities for adapting the exchange pattern to employment-related time frames. APD also has the potential to prolong technique success in patients failing CAPD rather than transferring them to hemodialysis. Nevertheless, APD remains more expensive and technically complicated, thereby missing the beauty of CAPD's simplicity. Therefore we believe that APD has its role in an integrated approach and that all patients should be informed of its potential. It would, however, not be correct to present APD as the preferred PD method for all patients, as it also has some drawbacks that make it less suitable for some categories of patients. In all cases, patients should have a free and informed choice.

Automation↗
PubMedDate not supplied

Effect of gender on various parameters of crush syndrome victims of the Marmara earthquake.

BACKGROUND: Detailed analyses on crush syndrome resulting from earthquakes is scarce. This study aimed to analyze the effect of gender on clinical course of the renal victims of the catastrophic Marmara earthquake that struck Northwestern Turkey in 1999. METHODS: Questionnaires were prepared within the first week of disaster and sent to 35 reference hospitals that treated the victims. Relationship between gender and various epidemiological, clinical, laboratory parameters, treatment modalities and outcome was then investigated. RESULTS: Of the 639 victims with renal dysfunction, 348 (54%) were males and 291 (46%) females. Mean age was 33 +/- 14 and 31 +/- 15 years in the male and female victims, respectively. At admission, males were characterized by a higher hematocrit and higher serum levels of creatinine, BUN, potassium and phosphorus, while other clinical and laboratory parameters as well as the number of fasciotomized and amputated extremities did not differ between the two genders. Males suffered from longer periods of oliguria, higher rates of sepsis and hypertension. 77.3% of the male patients needed dialysis support as compared to 71.5% in the females. The number of hemodialysis sessions and days for dialysis support were higher in the males. Last serum creatinine before discharge from the nephrology clinics was higher in male victims, while mortality rates were similar in both genders. CONCLUSION: Although males are characterized by more severe laboratory abnormalities of rhabdomyolysis, more frequently suffer from sepsis and need more intensive dialysis support, gender is not a prognostic indicator of final outcome in the renal victims of disasters.

Adolescent↗
PubMedDate not supplied

Relationship between fluid status and its management on acute renal failure (ARF) in intensive care unit (ICU) patients with sepsis: a prospective analysis.

BACKGROUND: Sepsis carries a high morbidity and mortality, further enhanced by acute renal failure (ARF). Although fluid loading can prevent ARF in dehydrated patients, this approach could be risky in septic patients, since it can deteriorate oxygenation. This study evaluates the relationship between fluid status and management and ARF development in septic patients. METHODS AND PATIENTS: Patients admitted to the ICU between 1 January 2001 and 31 December 2001 were included if serum creatinine (Cr) was <2 mg% on admission, and if they developed sepsis. ARF was determined as a doubling of serum Cr, an increase of serum Cr >2 mg%, or oliguria <500 ml/24 hr. RESULTS: 257 out of 2442 patients, admitted to the intensive care unit (ICU), developed sepsis, 29 developed ARF, 13 needed a renal replacement. ARF vs. non-ARF patients were older (65.2 +/- 13.3 vs. 55.1 +/- 17.4, p=0.002), had a higher central venous pressure (CVP) at day 1 (9.6 +/- 4.3 vs. 5.2 +/- 3.6 mmHg, p<0.001), and at day 2 (7.1 +/- 5.1 vs. 5.1 +/- 4.0 mmHg, p=0.03), a higher colloid fluid loading for the first 3 days (2037 +/- 1681 vs. 1116 +/- 1220 mL, p<0.03), a higher serum Cr (1.25 +/- 0.39 vs. 0.96 +/- 0.33 mg/dL, p=0.009) and an increase vs. a decrease in serum Cr during the first 24 hr (+0.30 +/- 0.58 vs. -0.31 +/- 0.45 mg/dL, p=0.02), a lower diuresis (1347 +/- 649 vs. 1849 +/- 916 mL, p=0.005). There was no difference in APACHE II scores (19.2 +/- 7.2 vs. 17.2 +/- 6.6, p=0.1), or MAP (64.5 +/- 12.4 vs. 67.9 +/- 12.4, p=0.18). The fraction of inspired oxygen (FiO2) need in the ARF group increased from 40.4 +/- 11.5 to 65.6 +/- 24.2% from day 1 to day 2 (p=0.04), where it remained unchanged in the non-ARF group. The use of diuretics was higher in the ARF group (21/29 vs. 43/228, p=0.001). CONCLUSION: Septic patients developing ARF have an elevated CVP at day 1 of sepsis, indicating cardiodepression or intrarenal causes for hypoperfusion. These patients develop ARF despite further fluid loading. Respiratory function deteriorated in patients with ARF. Persistent fluid challenges should be avoided if they do not lead to an improvement in renal function, or if oxygenation deteriorates.

APACHE↗