Publications by authors named "Charles Beerenhout"

28 Publications

  • Page 1 of 1

Severe hemodialysis access-induced distal ischemia may be associated with poor survival.

J Vasc Access 2021 Mar 26;22(2):194-202. Epub 2020 Jun 26.

Department of Surgery, Máxima MC, Veldhoven, The Netherlands.

Background: Some hemodialysis patients develop hemodialysis access-induced distal ischemia due to insufficient loco-regional perfusion pressure and consequent poor arterial flow. We hypothesized that patients with severe hemodialysis access-induced distal ischemia had worse survival compared with patients with mild or no hemodialysis access-induced distal ischemia.

Methods: This single-center retrospective observational cohort study included three groups of prevalent hemodialysis patients with an upper extremity vascular access between 2006 and 2018. Symptomatic patients had signs and symptoms of hemodialysis access-induced distal ischemia and low digital brachial indices (<60%) and were divided into a mild (Grade I-IIa) and a severe hemodialysis access-induced distal ischemia (IIb-IV) group. The control group consisted of hemodialysis patients without signs of hemodialysis access-induced distal ischemia with digital brachial indices ≥60%. Factors potentially related to 4-year survival were analyzed.

Results: Mild hemodialysis access-induced distal ischemia-patients displayed higher digital brachial indices ( = 23, 41%, ±3) compared with severe hemodialysis access-induced distal ischemia-patients ( = 28, 24%, ±4), whereas controls had the highest values ( = 48, 80%, ±2;  < .001). A total of 44 patients (44%) died during follow-up. Digital brachial index (hazards ratio 0.989 [0.979-1.000]  = .046) was related to overall mortality following correction for presence of arterial occlusive disease (hazards ratio 2.28 [1.22-4.29], diabetes (hazards ratio 2.00 [1.07-3.72], and increasing age (hazards ratio 1.03 [1.01-1.06] as was digital pressure (hazards ratio 0.990 [0.983-0.998],  = .011). Overall survival was similar in mild hemodialysis access-induced distal ischemia and controls (2-year, 79% ±5; 4-year, 57% ±6,  = .818). In contrast, 4-year survival was >20% lower in patients with severe hemodialysis access-induced distal ischemia (2-year 62%± 10; 4-year 34% ± 10;  = .026).

Conclusion: Presence of severe hemodialysis access-induced distal ischemia may be associated with poorer survival in hemodialysis patients. Lower digital brachial index values are associated with higher overall mortality, even following correction for other known risk factors.
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http://dx.doi.org/10.1177/1129729820933456DOI Listing
March 2021

Uraemic symptom burden and clinical condition in women and men of ≥65 years of age with advanced chronic kidney disease: results from the EQUAL study.

Nephrol Dial Transplant 2019 07;34(7):1189-1196

ERA-EDTA Registry, Department of Medical Informatics, Academic Medical Center, Amsterdam Public Health Research Institute, University of Amsterdam, Amsterdam, The Netherlands.

Background: The epidemiology and prognosis of chronic kidney disease (CKD) differ by sex. We aimed to compare symptom prevalence and the clinical state in women and men of ≥65 years of age with advanced CKD receiving routine nephrology care.

Methods: The European QUALity study on treatment in advanced chronic kidney disease (EQUAL) study follows patients from six European countries of ≥65 years of age  years whose estimated glomerular filtration rate (eGFR) dropped to ≤20 mL/min/1.73 m2 for the first time during the last 6 months. The Dialysis Symptom Index was used to assess the prevalence and severity of 33 uraemic symptoms. Data on the clinical state at baseline were collected from medical records. Prevalence was standardized using the age distribution of women as the reference.

Results: The results in women (n = 512) and men (n = 967) did not differ with age (77.0 versus 75.7 years) or eGFR (19.0 versus 18.5). The median number of symptoms was 14 [interquartile range (IQR) 9-19] in women, and 11 (IQR 7-16) in men. Women most frequently reported fatigue {39% [95% confidence interval (CI) 34-45]} and bone/joint pain [37% (95% CI 32-42)] as severe symptoms, whereas more men reported difficulty in becoming sexually aroused [32% (95% CI 28-35)] and a decreased interest in sex [31% (95% CI 28-35)]. Anaemia [73% (95% CI 69-77) versus 85% (95% CI 82-87)] was less common in women than in men, as were smoking history and cardiovascular comorbidity. However, a diagnosis of liver disease other than cirrhosis, psychiatric disease and mild malnutrition were more common among women.

Conclusions: Women in secondary care with an incident eGFR ≤20 mL/min/1.73 m2 reported a higher symptom burden, while their clinical state was considered similar or even more favourable as compared with men.
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http://dx.doi.org/10.1093/ndt/gfy155DOI Listing
July 2019

Synthetic ACTH in High Risk Patients with Idiopathic Membranous Nephropathy: A Prospective, Open Label Cohort Study.

PLoS One 2015 12;10(11):e0142033. Epub 2015 Nov 12.

Radboud university medical center, Radboud Institute for Health Sciences, Department of Nephrology, Nijmegen, The Netherlands.

New therapeutic agents are warranted in idiopathic membranous nephropathy. Synthetic ACTH may be advantageous with reported remission rates up to 85% and few side effects. We conducted a prospective open label cohort study from 2008 till 2010 (NCT00694863). We prospectively selected patients with idiopathic membranous nephropathy and high risk for progression (defined as βeta-2-microglobulin (β2m) excretion of >500 ng/min). For comparison, we selected matched historical controls treated with cyclophosphamide. The prospectively selected patients received intramuscular injections of synthetic ACTH during 9 months (maximal dose 1 mg twice a week). The primary endpoints concerned the feasibility and incidence of remissions as a primary event. Secondary endpoints included side effects of treatment and the incidence of remissions and relapses at long-term follow-up. Twenty patients (15 men) were included (age 54±14 years, serum creatinine 104 μmol/l [IQR 90–113], urine protein:creatinine ratio 8.7 g/10 mmol creatinine [IQR 4.3–11.1]). Seventeen patients (85%) completed treatment. 97% of injections were administered correctly. Cumulative remission rate was 55% (complete remission in 4 patients, partial remission 7 patients). In a group of historical controls treated with cyclophosphamide and steroids, 19 of 20 patients (95%) developed a remission (complete remission in 13 patients, partial remission in 6 patients) (p<0.01). The main limitation of our study is its small size and the use of a historical control group. We show that treatment with intramuscular injections of synthetic ACTH is feasible. Our data suggest that synthetic ACTH is less effective than cyclophosphamide in inducing a remission in high risk patients with idiopathic membranous nephropathy. The use of synthetic ACTH was also associated with many adverse events. Therefore, we advise against synthetic ACTH as standard treatment in membranous nephropathy.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0142033PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4642982PMC
June 2016

[AL amyloidosis-associated factor X deficiency].

Ned Tijdschr Geneeskd 2014 ;158(6):A6678

UMC Groningen, Groningen.

Background: An acquired bleeding tendency is a specific symptom that can indicate an underlying disease.

Case Description: Here we describe a 69-year-old patient with an acquired bleeding tendency resulting from a factor X deficiency due to an underlying amyloid light-chain (AL) amyloidosis. Factor X deficiency in AL amyloidosis arises from a quantitative and qualitative deficiency of factor X because it binds to amyloid fibrils exposed to circulating blood.

Conclusion: Bleeding tendency is a rare complication of AL amyloidosis, often resulting from a factor X deficiency.
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November 2014

Antiangiogenic factors and maternal hemodynamics during intensive hemodialysis in pregnancy.

Hemodial Int 2013 Oct 1;17(4):639-43. Epub 2013 Apr 1.

Department of Internal Medicine, Division of Nephrology, Maastricht University Medical Center, Maastricht, The Netherlands.

We report on a 21-year-old pregnant patient with IgA nephropathy who was initiated on intensive hemodialysis (8 hours of hemodialysis 3 times a week) at a gestational age of 26 weeks on the basis of worsening kidney function resulting in rapidly progressive fatigue and difficulties in metabolic control. Throughout the pregnancy, and while on intensive hemodialysis, 24-hour ambulatory blood pressure control was within the target, and results of weekly 24-hour measurement of central hemodynamics and pulse wave velocity, and of serial levels of circulating (anti-)angiogenic factors were comparable to normal pregnancies. Estimated fetal growth evolved along the 50th percentile, and no polyhydramnios was detected. After induction for a sudden, unexplained increase in blood pressure, she delivered a healthy boy of 2480 g at a gestational age of 36 weeks. This case adds to the expanding literature that supports the use of intensive hemodialysis in pregnant patients with end-stage renal disease and illustrates, for the first time, the potential use of serial (anti-) angiogenic factors and 24-hour measurements of blood pressure and hemodynamic indices in order to facilitate monitoring of these complicated patients.
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http://dx.doi.org/10.1111/hdi.12042DOI Listing
October 2013

Agreement between different parameters of dialysis dose in achieving treatment targets: results from the NECOSAD study.

Nephrol Dial Transplant 2012 Mar 4;27(3):1145-52. Epub 2011 Aug 4.

Department of internal medicine, Máxima Medical Centre, Veldhoven, Leiden, The Netherlands.

Background: The recommended parameter of dialysis dose differs between K-DOQI and the European Best Practice Guidelines. It is not well known to what extent an agreement exists between the different parameters, nor if target and delivered dialysis dose are prescribed according to the urea reduction rate (URR), single-pool Kt/V (spKt/V) or equilibrated double-pool Kt/V (eKt/V) and which parameter is most strongly related to mortality.

Methods: In 830 haemodialysis patients from the NECOSAD cohort URR, spKt/V and eKt/V were calculated and compared according to a classification regarding the recommended treatment targets (70%, 1.4 and 1.2, respectively) as well as minimum delivered dialysis dose (65%, 1.2 and 1.05, respectively). Moreover, the relation between treatment dose and survival was assessed using Cox regression analysis.

Results: A spKt/V of ≥1.4 and URR ≥70% corresponded with eKt/V ≥1.20 (as reference method) in, respectively, 98.0 and 90.6% of patients. spKt/V of ≥1.2 and URR ≥65% corresponded with eKt/V ≥1.05 in, respectively, 95.5 and 91.2% of patients. Deviations from the reference method were significantly related to differences in urea distribution volume (spKt/V), treatment time (URR) and ultrafiltration volume (URR). The adjusted HR (95% CI) was 0.98 (0.96, 0.99) for URR, 0.51 (0.31, 0.84) for spKt/V and 0.46 (0.30, 0.80) for the eKt/V.

Conclusion: The use of URR leads to larger disagreement with the reference method (eKt/V) treatment target as compared to spKt/V. Low urea distribution volume, short treatment time and low ultrafiltration volumes are predictive parameters for overestimation of dialysis dose when utilizing the alternative methods spKt/V and URR instead of eKt/V. Delivered eKt/V, spKt/V and URR were all positively related to survival.
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http://dx.doi.org/10.1093/ndt/gfr396DOI Listing
March 2012

Variations in predialytic plasma conductivity in dialysis patients: effect on ionic mass balance and blood pressure.

ASAIO J 2011 Jan-Feb;57(1):53-61

Department of Internal Medicine, Maxima Medical Centre, Veldhoven, The Netherlands.

In this study, variations in plasma conductivity (PC), as a surrogate marker of plasma sodium, as well as its relation with intradialytic ionic mass balance (IMB) and blood pressure were assessed in 73 patients. Plasma conductivity and IMB were retrieved on a treatment to treatment basis during a 6-month period. Dialysate sodium concentration was 140 mmol/L. A total of 4070 treatments were analyzed. Mean coefficient of variation for predialytic PC was 1.3%, and mean intraindividual range in predialytic PC measurements during the 6-month follow-up period was 0.9 mS/cm (plasma sodium ∼ 9 mmol/L). Predialytic PC was related to both diffusive and total IMB (r = 0.91, p < 0.001; and r = 0.35, p < 0.01). The average diffusive IMB over a 6-month period was negative in 33% of patients, and the average PC increased during dialysis in 14% of patients. Averaged predialytic PC was significantly related to systolic blood pressure (r = 0.35; p < 0.01), whereas within patients, predialytic systolic blood pressure was significantly different between treatments with the lowest and highest predialytic PC (139 ± 24 vs. 147 ± 21 mm Hg; p < 0.05). In conclusion, depending on PC, diffusive ionic transfer from dialysate to patient may occur in a significant percentage of patients using a dialysate sodium concentration of 140 mmol/L. Variations in PC are related to blood pressure, which might suggest a volume-independent effect of sodium.
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http://dx.doi.org/10.1097/MAT.0b013e3182078b66DOI Listing
April 2011

The influence of bicarbonate/lactate-buffered PD fluids on N{ε}-(carboxyethyl)lysine and N{ε}-(carboxymethyl)lysine in peritoneal effluent.

Perit Dial Int 2011 Mar-Apr;31(2):189-93. Epub 2010 Jul 29.

Division of Nephrology, Department of Internal Medicine, Maastricht University Medical Centre (MUMC), The Netherlands.

Objective: Accumulation of advanced glycation end products (AGEs) may be involved in the pathogenesis of peritoneal membrane dysfunction. As glycoxidation may play an important role in AGE formation, peritoneal dialysis fluids with low levels of glucose degradation products (GDPs) might result in a reduction in AGE concentration in the peritoneal effluent. The aim of this study was to compare the effects of conventional glucose-containing dialysis solutions and low GDP level fluids on the concentration of the AGEs N(ε)-(carboxymethyl)lysine (CML) and N(ε)-(carboxyethyl)lysine (CEL) in peritoneal effluent.

Design: Prospective randomized control study.

Methods: 23 patients were treated with either conventional glucose-containing fluid (n = 11, group A) or low level GDP fluid (n = 12, group B) during a period of 12 weeks. Before and after this period, CML and CEL were measured in peritoneal effluent.

Results: In groups A and B there were changes in CML concentrations [respectively 13.7 ± 17.0 and -16.0 ± 46.0 nmol/L (NS)] and CEL concentrations (respectively 20.3 ± 26.6 and -8.8 ± 18.9 nmol/L, p = 0.015). Residual renal function (RRF) in groups A and B was, respectively, 6.8 and 6.1 mL/min (NS). CML, but not CEL, in the peritoneal effluent was inversely related to RRF (r = -0.67, p < 0.05).

Conclusion: CEL, but not CML, in the peritoneal effluent appears to be influenced by the prescription of low GDP level fluid, probably due to the highly reduced concentration of methylglyoxal, which is needed for formation of CEL. CML is primarily influenced by RRF.
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http://dx.doi.org/10.3747/pdi.2010.00009DOI Listing
January 2012

Haemodialysis decreases finger pressures independent of artificial kidney blood flow.

Nephrology (Carlton) 2010 Aug;15(5):555-9

Departments of Surgery, Máxima Medical Center-Veldhoven, PO box 7777, 5500 MB Veldhoven, The Netherlands.

Background: During haemodialysis, some patients experience intensification of symptoms of haemodialysis access-induced distal ischaemia. Aim of this study is to compare the effects of two different regimens of arterial blood flow in patients with an arteriovenous access.

Methods: A questionnaire identified 10 patients that subjectively experienced ischaemic symptoms during haemodialysis. Systolic blood pressure, heart rate, finger pressure (P(dig)), finger temperature (T(dig)), oxygen saturation and ischaemic scores were monitored during two different arterial blood flow dialysis sessions.

Results: Before dialysis, P(dig) and T(dig) of the arteriovenous access hand were significantly lower compared with the other hand. Haemodialysis induced a drop of P(dig) in both hands. All changes in P(dig) occurred independent of the artificial kidney's blood flow level.

Conclusion: Systemic hypotension following onset of haemodialysis further intensifies an already diminished hand perfusion. Measures preventing dialytic hypotension will likely attenuate symptoms associated with haemodialysis access-induced distal ischaemia during haemodialysis.
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http://dx.doi.org/10.1111/j.1440-1797.2009.01271.xDOI Listing
August 2010

Influence of the preceding dwell time on the peritoneal equilibration test with 3.86% glucose solution in automated peritoneal dialysis.

Perit Dial Int 2010 Jan-Feb;30(1):95-8

Internal Medicine, Maastricht UMC, Maastricht, The Netherlands.

Objective: The peritoneal equilibration test (PET) using 3.86% glucose solution is preceded by a long dwell with 3.86% glucose solution. A point of concern in patients treated with automated peritoneal dialysis (APD) is the influence of the preceding short nightly dwells on the results of a standardized PET. The aim of the study was to compare net ultrafiltration, small solute transport, sodium sieving, and solute transport type between a PET preceded by a long night dwell and one preceded by short (APD) dwells.

Patients And Methods: 13 stable APD patients (mean age 60 +/- 15 years; mean duration of peritoneal dialysis 31 +/- 15 months) underwent 2 PETs: 1 preceded by short nightly dwells (PET A) and 1 preceded by a long night dwell (PET B).

Results: Both PETs were performed within a mean period of 8 (range 5 - 11) days. Mean total ultrafiltration of PET A was 626 +/- 218 mL and PET B was 644 +/- 223 mL (NS). The 4-hour results of both tests for dialysate-to-plasma (D/P) ratios of creatinine and urea, D(t)/D(0) ratios of glucose, and the dip in D/P sodium (sodium sieving) were similar. Classification of transport categories was identical for 10 of 13 patients.

Conclusion: In APD, the preceding dwell time of a 3.86% glucose PET does not influence fluid transport, solute transport, or transport type.
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http://dx.doi.org/10.3747/pdi.2009.00068DOI Listing
February 2011

Conductivity pulses needed for Diascan® measurements: does it cause sodium burden?

NDT Plus 2009 Aug;2(4):334-5

Department of Internal Medicine , University Hospital , Maastricht The Netherlands E-mail:

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http://dx.doi.org/10.1093/ndtplus/sfp059DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4421241PMC
August 2009

Evolution of protein-bound uraemic solutes during predilution haemofiltration.

J Nephrol 2009 May-Jun;22(3):352-7

Renal Division, University Hospital Gent, Gent - Belgium.

Background: Protein-bound uraemic toxins provoke multiple biological changes involved in uraemia. Few if any dialytic strategies remove these compounds.

Methods: In this post hoc analysis of remnant samples from a randomised controlled trial, we evaluate whether predilution haemofiltration (HF) decreases the pretreatment concentration of protein- bound uraemic solutes. Patients treated with low-flux haemodialysis (HD) were enrolled into a group continuing this strategy (group A, n=8) over 6 months, whereas group B (n=12) was switched to predilution online HF. Blood was sampled at baseline and after 6 months to determine total and free concentration and percentage binding of indoxyl sulfate (IS), indole-3-acetic acid (IAA), hippuric acid (HA), p-cresol (PC) and 3-carboxy- 4-methyl-5-propyl-2-furanpropionic acid (CMPF).

Results: Comparing concentrations at start versus 6 months of treatment by paired analysis, HD had no impact. In contrast, at the end of the HF period, we found a decrease in total and free PC, free IAA and total CMPF. In addition, the percentage protein binding of IAA increased significantly. However, unpaired analysis revealed no statistical difference between HD and HF, both at baseline and after 6 months of treatment for all compounds.

Conclusions: Paired analysis showed a beneficial impact of predilution online HF for several proteinbound uraemic solutes. Unpaired analysis, however, showed no statistical difference.
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September 2009

Banding of hemodialysis access to treat hand ischemia or cardiac overload.

Semin Dial 2009 Mar-Apr;22(2):204-8

Department of Surgery, Máxima Medical Center, de Run 4600, Veldhoven, The Netherlands.

A hemodialysis access may lead to cardiac overload (CO) or hand ischemia [hemodialysis access induced distal ischemia (HAIDI). Surgical banding restricts access flow and promotes distal perfusion. Aim of the study was to investigate short- and long-term clinical success of banding in these patient groups. After evaluation using a standard protocol, banding procedures (n = 19) were performed in patients (n = 17) with a hemodialysis access flow > or =2 l/minute or with refractory HAIDI. Various parameters including access flow, digital brachial index (DBI), and symptomatology of hand ischemia using a standard scoring system were determined before and after the operation. Surgical banding in CO patients (n = 9) lowered access flows by 2 l (Flow(preop) 3.2 +/- 0.3 l/minute vs. Flow(postop) 1.2 +/- 0.1 l/minute, p < 0.001). Banding in HAIDI patients (n = 10) increased DBI from 0.52 +/- 0.08 to 0.65 +/- 0.08 (p = 0.05), whereas ischemic symptomatology was attenuated (153 +/- 33 to 42 +/- 15, p < 0.02). All patients successfully continued dialysis, and immediate access occlusions (<3 months) were not observed. Access flows remained at acceptable levels after a mean follow-up of 30 months in surviving patients (n = 11, flow: 1.0 +/- 0.1 l/min). Two patients were reoperated for recurrent CO (one and 28 months postoperatively). Surgical banding monitored by measurement of flow and finger pressures is an effective short- and long-term treatment modality for hemodialysis access related CO or distal ischemia.
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http://dx.doi.org/10.1111/j.1525-139X.2008.00537.xDOI Listing
August 2009

Ionic dialysance and the assessment of Kt/V: the influence of different estimates of V on method agreement.

Nephrol Dial Transplant 2007 Aug 5;22(8):2276-82. Epub 2007 Jun 5.

Department of Internal Medicine, Máxima Medical Centre, Veldhoven, The Netherlands.

Background: Ionic dialysance was recently introduced as a means to assess Kt/V (K(ID)t/V). With this method, urea distribution volume (V) has to be estimated. The primary aim of the present study was to assess the agreement between equilibrated Kt/V assessed by urea kinetic modelling (eKt/V) with K(ID)t/V taking into account different estimates of V, and to assess the monthly variation in V. Secondly, the mechanisms behind the intra-treatment changes in ionic dialysance and inter-treatment variability of K(ID)t/V were assessed.

Methods: Sixty-six patients were included. eKt/V was estimated using 30 min post-treatment sampling in the second generation Daugirdas equation. V was assessed by the formulae of Watson and Chertow (V(Watson); V(Chertow)), double-pool urea kinetic modelling (V(UKM)) and by ionic dialysance (V(IOD)) [Diascan; Hospal(R)].

Results: The use of V(UKM) or V(IOD) instead of V(Watson) or V(Chertow) improved the relation between eKt/V and K(ID)t/V (both r = 0.93; P < 0.001 vs r = 0.84 and r = 0.81; P < 0.001). Mean values of eKt/V (1.19 +/- 0.21), K(ID)t/V(UKM) (1.19 +/- 0.30) and K(ID)t/V(IOD) (1.21 +/- 0.25) were comparable. Intra-class correlation coefficient of V(IOD) was 0.87 with a 1-month interval and <0.75 after 2 and 3 months. Intra-class correlation coefficient of V(DP) was 0.79 with a 1-month interval and <0.75 after 2 and 3 months. Inter-treatment variation in K(ID)t/V during six consecutive dialysis sessions was 6.1% +/- 0.6%. Changes in blood flow were the main determinant of variations in K(ID)t/V (P < 0.05). During treatment, ionic dialysance decreased by 12 +/- 13 ml/min (P < 0.001). The decline in blood volume was the major determinant of the intra-dialytic change in ionic dialysance (P < 0.05).

Conclusion: The use of V(IOD) and V(UKM) results in better agreement between eKt/V and K(ID)t/V compared with anthropometric formulae. K(ID)t/V was comparable with eKt/V and thus lower than expected for a single-pool method. V(IOD) and V(UKM), should be assessed at least monthly. K(ID)t/V varies widely between consecutive dialysis sessions, mainly due to differences in blood flow. During treatment, ionic dialysance decreases, which is related to the relative decline in blood volume.
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http://dx.doi.org/10.1093/ndt/gfm108DOI Listing
August 2007

Access flow, venous saturation, and digital pressures in hemodialysis.

J Vasc Surg 2007 May 26;45(5):968-73. Epub 2007 Mar 26.

Department of Surgery, Máxima Medical Center, Veldhoven, The Netherlands.

Background: A hemodialysis arteriovenous fistula (AVF) requires surgical modification in patients with cardiac overload or dialysis access-associated steal syndrome (DASS). Creation of an artificial stenosis (banding) within the AVF may be used, but this technique lacks the guidance of objective parameters. The aim of this pilot study was to identify indicators that reflect AVF flow in dialysis patients with either access-related cardiac overload (CO) or DASS requiring corrective surgery.

Methods: Patients underwent serial measurements of subclavian venous saturation (Sat(ven)), access flow (Flow(us)), and index digital pressures (P(dig)) during a corrective banding procedure.

Results: Data were obtained in 14 individuals (9 men; mean age, 53 +/- 6 years) during 16 studies (CO, n = 8; DASS, n = 8). Before surgery, correlations between preoperative flow, Sat(ven) and P(dig) were not significant. Stepwise banding of the AVF altered Sat(ven) in both groups from a mean of 91% +/- 1% (open AVF) to 84% +/- 2% (closed AVF, P < .001). The CO patients demonstrated a larger drop (-13%) compared with the DASS patients (-4%). Values of P(dig) increased from 68 +/- 9 to 90 +/- 9 mm Hg (P < .001), and both groups demonstrated a similar +23 mm Hg increase. In concert, the digital brachial index also significantly improved in all patients from 0.60% +/- 0.09% to 0.74% +/- 0.10%. Linearity was present between alterations in Flow(us) and Sat(ven) in all patients, but mostly in the CO patients (r(2) = 0.96).

Conclusions: Stepwise banding of hemodialysis fistulas leads to dose-dependent decreases in flow and ipsilateral subclavian venous saturation combined with augmented digital pressures in patients with cardiac overload and dialysis associated steal syndrome. Intraoperative measurements of venous saturation and digital pressures may have the potential of guiding surgical correction in these patients.
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http://dx.doi.org/10.1016/j.jvs.2006.12.064DOI Listing
May 2007

An evaluation of blood volume changes during ultrafiltration pulses and natriuretic peptides in the assessment of dry weight in hemodialysis patients.

Hemodial Int 2007 Jan;11(1):51-61

Atrium Hospital Medical Centre, Gelderse vallei Hospital, Ede, The Netherlands.

Changes in blood volume (BV) during dialysis as well as plasma levels of brain natriuretic peptide (BNP) and N-terminal (NT) pro-BNP levels are possible tools to assess dry weight in hemodialysis (HD) patients. The aim of the study was to compare these parameters with other non-invasive techniques used to assess dry weight in HD patients, and to study their relation with intradialytic hypotension (IDH) and the presence of cardiovascular disease BV changes during HD, both during regular dialysis and during an ultrafiltration pulse, plasma levels of NT pro-BNP and BNP, and vena cava diameter index (VCDI) were assessed in a cohort of 66 HD patients, which was subdivided according to tertiles of total body water (TBW) corrected for body weight, assessed by bioimpedance analysis. Parameters were also related to the presence of IDH and history of cardiovascular disease. The decline in BV during regular dialysis and during an ultrafiltration pulse, as well as VCDI and BNP were significantly different between the tertiles of normalized TBW, but refill after the ultrafiltration pulse and NT pro-BNP were not. Only VCDI and the decline in BV during regular dialysis were significantly different between patients with or without IDH. Vena cava diameter index, BNP, and NT pro-BNP were significantly higher in patients with cardiovascular disease. Using bioimpedance as the reference method, changes in BV, either during regular dialysis or during an ultrafiltration pulse, as well as VCDI and BNP are all indicative of hydration state in dialysis patients, but refill after an ultrafiltration pulse is not. Only VCDI and BV changes were related to IDH. The presence of cardiovascular disease appears to influence both VCDI as well as BNP.
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http://dx.doi.org/10.1111/j.1542-4758.2007.00154.xDOI Listing
January 2007

The effect of sodium profiling and feedback technologies on plasma conductivity and ionic mass balance: a study in hypotension-prone dialysis patients.

Nephrol Dial Transplant 2006 Jan 6;21(1):138-44. Epub 2005 Sep 6.

Department of Internal Medicine, Maxima Medical Centre, Veldhoven and University Hospital Maastricht, PO Box 5800, 6202 AZ Maastricht, The Netherlands.

Background: Sodium profiling improves haemodynamic tolerance in haemodialysis (HD) patients but may also influence sodium homeostasis. Changes in blood volume and plasma conductivity (PC) during HD can be modelled by feedback technology, but their effects on sodium homeostasis are not widely studied.

Methods: This randomized crossover study compared PC and ionic mass balance (IMB) as surrogate markers of sodium balance between standard HD [dialysate conductivity (DC) 14.0 mS/cm], sodium profiling (DC 15.0-->14.0 mS/cm), blood volume (BV)-controlled and PC-controlled feedback (target: post-HD PC: 14.0 mS/cm) in 10 HD patients with frequent hypotension.

Results: 440 treatments were studied. Pre-dialytic PC was significantly higher during SP (14.4+/-0.2 mS/cm) compared to standard HD (14.2+/-0.3 mS/cm), and was not different between the other manoeuvres: PC-controlled (14.1+/-0.3 mS/cm), and BV-controlled feedback (14.2+/-0.2 mS/cm). Except for the first treatment, during which IMB was lower during the sodium profile, IMB did not differ significantly between the various manoeuvres and was strongly dependent upon ultrafiltration volume and the difference between pre-dialytic PC and DC. Symptomatic hypotensive episodes occurred least frequently during BV-controlled feedback (8%) compared to the other manoeuvres (standard HD, 16%; sodium profile, 14%; PC-controlled feedback, 17%), but differences were not significant. Inter-dialytic weight gain and pre-dialytic systolic blood pressure did not differ.

Conclusions: Pre-dialytic PC increased during the sodium profile, and did not differ between BV- or PC-controlled feedback compared to standard HD. Thus, it appears that both BV- and PC-controlled feedback can be safely prescribed without substantial salt- and water-loading, at least in the short term. Analysis of IMB is useful to assess differences in sodium balance between single treatment sessions but appears of less value in a steady-state situation.
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http://dx.doi.org/10.1093/ndt/gfi118DOI Listing
January 2006

Pre-dilution on-line haemofiltration vs low-flux haemodialysis: a randomized prospective study.

Nephrol Dial Transplant 2005 Jun 22;20(6):1155-63. Epub 2005 Mar 22.

Department of Nephrology, University Hospital Maastricht, PO Box 5800, 6202 AZ Maastricht, The Netherlands.

Background: Accumulation of larger molecular weight uraemic toxins molecules may have a negative effect on the cardiovascular and nutritional state of dialysis patients and influence uraemic symptomatology. Their clearance can be enhanced by the use of haemofiltration (HF).

Methods: The effects of low-flux haemodialysis (HD) (ultrapure dialysate; polyamide membranes) and pre-dilution on-line HF (1:1 blood/substitution ratio; target filtration volume: 1.2 times body weight) on cardiovascular and nutritional parameters, interdialytic levels of uraemic toxins and quality of life (QOL; Laupacis questionnaire) were assessed during 1 year follow-up. Forty patients were randomized.

Results: After 1 year, 27 patients were eligible for analysis (HF: 13 patients; HD: 14 patients). Left ventricular mass index did not change in the HF patients (127+/-33 --> 131+/-36 g/m(2) after 12 months) or in the HD group (135+/-34 --> 138+/-32 g/m(2)). Also, there were no changes in pulse wave velocity, and 48 h systolic and diastolic blood pressures. Lean body mass, assessed by dual-energy X-ray absorptiometry, increased in the HF group (44.8+/-8.9 --> 46.2+/-9.6 kg; P<0.05), but not in the HD group (49.4+/-9.2 --> 50.6+/-8.8 kg), although differences between groups were not significant. Insulin-like growth factor-1 levels remained stable in the HF patients, but decreased in the HD group (P<0.05 between groups). QOL for physical symptoms improved in the HF group (4.2+/-1.2 --> 5.0+/-1.1; P<0.05 within the HF group and P = 0.06 between groups), but not in the HD group (4.0+/-1.0 --> 4.4+/-1.4). beta2-microglobulin, complement factor D and homocysteine decreased significantly in the HF but not in the HD group, whereas l-ADMA, leptin and advanced glycation end-products-related fluorescence did not change.

Conclusions: No changes in cardiovascular parameters were observed during pre-dilution on-line HF compared with low-flux HD. Treatment with on-line HF resulted in marked changes in the uraemic toxicity profile, an improvement in physical well-being and a small improvement in nutritional state.
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http://dx.doi.org/10.1093/ndt/gfh775DOI Listing
June 2005

Haemodynamics and electrolyte balance: a comparison between on-line pre-dilution haemofiltration and haemodialysis.

Nephrol Dial Transplant 2004 Sep 20;19(9):2354-9. Epub 2004 Jul 20.

Department of Internal Medicine, University Hospital Maastricht, PO Box 5800, 6202 AZ Maastricht, the Netherlands.

Background: An important advantage of convective therapies is improved vascular reactivity. However, it is not well known whether the vascular response during convective therapies remains superior when compared to haemodialysis (HD) with an adjusted temperature of the dialysate. It has also been suggested that convective therapies may impair small electrolyte removal through an effect on the Donnan equilibrium. In the present study, we compared the haemodynamic response and small electrolyte removal between pre-dilution on-line haemofiltration (HF) and HD procedures.

Methods: Cardiac output (CO), central blood volume (CBV) and peripheral vascular resistance (PVR) were assessed, using the saline dilution technique, in 12 stable patients during HF and HD with two different temperatures of the dialysate [36.5 and 35.5 degrees C (HD(36.5) and HD(35.5))]. Balances for sodium, potassium, calcium and conductivity were assessed using total dialysate/filtrate collections. Target filtration volume for HF was 1.2 times body weight. The temperature of the infusate was 36.5 degrees C.

Results: The change (Delta) in CBV was less during HD with a dialysate temperature of 35.5 degrees C (-0.03+/-0.14 l; P<0.05) compared to HF (-0.16+/-0.05 l) and HD(36.5) (-0.11+/-0.14 l), but the other haemodynamic parameters did not differ between the studied techniques. DeltaPVR was significantly related to DeltaCBV (r = -0.46; P<0.01), whereas DeltaCBV was related to ultrafiltration rate (r = -0.34; P = 0.05). DeltaCO was related to DeltaCBV (r = 0.62; P<0.001). Solute balances did not differ between HF and HD.

Conclusion: Using the saline dilution method, no difference in the change in CO and PVR was observed between on-line HF vs HD(36.5) and HD(35.5). Only CBV declined to a significantly lesser degree during HD(35.5), although absolute differences were small. Changes in the other haemodynamic variables appeared more dependent upon the degree and rapidity of fluid removal than upon the treatment modality. No difference in small electrolyte balance was observed between HF and HD, suggesting that ionic removal is not impaired during on-line HF.
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http://dx.doi.org/10.1093/ndt/gfh315DOI Listing
September 2004

Reference values for multifrequency bioimpedance analysis in dialysis patients.

Blood Purif 2004 ;22(3):301-6

St. Catharina Hospital, Eindhoven, The Netherlands.

Background: The role of multifrequency bioimpedance(MF-BIA) in the assessment of fluid status in dialysis patients is still not fully elucidated. Especially, the predictive value of reference values for extracellular water (ECW) has not yet been addressed. Aim of the present study was to validate cut-off values for MF-BIA in the diagnosis of hypervolemia in dialysis patients, using strict clinical criteria and echocardiography as reference techniques.

Methods: 90 patients [42 on hemodialysis; 48 on peritoneal dialysis] were divided into the following groups: clinically normovolemic (mean 24- or 48-hour systolic blood pressure below 133 mm Hg without use of antihypertensive agents; n = 12), 'hypervolemic' (mean systolic blood pressure above 133 mm Hg with 2 or more antihypertensive agents; n = 34) or undetermined (n = 44). The 80th percentile for normalized ECW in the clinically normovolemic patients was used as reference value. 20 healthy age-matched controls were included for comparison.

Results: The 80th percentiles for ECW:body weight (BW) and ECW:height in 'normovolemic' subjects were, respectively, 0.245 liters/kg and 10.96 liters/m in males, and 0.232 liters/kg and 9.13 liters/m in females. ECW:BW and ECW:height were above these values in, respectively, 26 (sensitivity 76%) and 29 (sensitivity 86%) of the 34 'hypervolemic' patients. In the undetermined group, left ventricular end-diastolic diameter was significantly different between patients with normalized ECW below and above these cut-off values (49.0 +/- 5.1 vs. 52.4 +/- 5.7 mm; p < 0.05). Use of the ECW:TBW ratio resulted yielded low sensitivity (45%). ECW:height was lower in the 'normovolemic' dialysis patients compared to healthy controls (9.7 +/- 1.3 l/m versus 12.2 +/- 1.9 l/m).

Conclusion: In our study population, ECW by MF-BIA, normalized for height was able to predict hypervolemia, based on strict clinical criteria, with a sensitivity of 86% and a specificity of 80%. The normalization procedure for ECW may influence the classification of hydration status. Strictly normotensive dialysis patients had lower normalized ECW than healthy control subjects.
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http://dx.doi.org/10.1159/000078761DOI Listing
February 2005

The relationship between reticulocyte hemoglobin content with C-reactive protein and conventional iron parameters in dialysis patients.

J Nephrol 2004 Jan-Feb;17(1):107-11

Department of Clinical Chemistry, University Hospital Maastricht, The Netherlands.

Adequate iron stores are a prerequisite for successful erythropoietin (EPO) therapy in hemodialysis (HD) patients. Nevertheless, iron status estimation in HD patients remains problematic, as most parameters are influenced by inflammation. The reticulocyte hemoglobin content (CHr) has recently been proposed as a useful tool in iron status assessment. However, the effect of inflammation on CHr remains unstudied. This study aimed to assess the relationship between CHr with other parameters of iron status as well as with C-reactive protein (CRP). This relationship was studied in all the patients (n=61) at our dialysis unit. CHr was significantly and positively related to transferrin saturation (TS) (rho=0.26; p<0.05) and inversely to the percentage of hypochromic red blood cells (%Hypo) (rho=-0.63; p<0.0001), but not to serum ferritin. CHr was strongly and inversely related to log CRP (rho=-0.50; p<0.0001). Despite the use of maintenance intravenous (i.v.) iron doses and relatively high serum ferritin levels, a large percentage of patients were in a state of functional iron deficiency (%Hypo > or = 6 in 41% of patients and CHr < or = 29 pg in 13% of patients). This percentage was far lower in patients with CRP levels below the detection limit (2 mg/L) (26% and 0%, respectively). In conclusion, CHr is related to both TS and %Hypo, but not to serum ferritin, and is strongly influenced by the presence of inflammation (as determined by CRP). In patients with elevated CRP levels, it is very difficult to reach target iron status levels without exceeding the upper limits for serum ferritin.
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June 2004

Nitric oxide synthetic capacity in relation to dialysate temperature.

Blood Purif 2004 ;22(2):203-9

Department of Internal Medicine, University Hospital Maastricht, Maastricht, The Netherlands.

Background: During hemodialysis, vascular reactivity is impaired, which can be corrected by lowering dialysate temperature. It has also been shown that nitric oxide (NO) is related to intradialytic hypotension. As NO synthesis may be temperature-dependent, this study addressed the influence of dialysate temperature on the NO synthetic capacity of plasma.

Methods: NO synthetic capacity was studied during hemodialysis with a dialysate temperature of 37.5 degrees C (dialysis-37.5 degrees C) and programmed extracorporeal blood cooling (cool dialysis; Blood Temperature Monitor; Fresenius C) in 12 stable patients. NO synthetic capacity was assessed ex vivo by [3H]L-citrulline formation from [3H]L-arginine in cultured endothelial cells after incubation with plasma samples obtained during the respective sessions.

Results: Core temperature decreased (-0.32 +/- 0.10 degrees C) and energy transfer rate was significantly lower (-27.5 +/- 2.8 W; p < 0.05) during cool dialysis compared to dialysis-37.5 degrees C (0.19 +/- 0.06 degrees C and -0.8 +/- 1.2 W respectively; p < 0.05). Systolic blood pressure decreased during dialysis-37.5 degrees C (-19 +/- 4 mm Hg; p < 0.05), but not during cool dialysis (-6 +/- 5 mm Hg). NO synthetic capacity increased during dialysis-37.5 degrees C (55.5 +/- 9.3 to 73.5 +/- 10.2 pmol/10(5) cells; p < 0.05), in contrast to cool dialysis (67.3 +/- 11.1 to 66.2 +/- 10.8 pmol/10(5) cells).

Conclusion: The stimulatory effect of uremic plasma on endothelial NO synthesis was augmented during dialysis-37.5 degrees C but not during cool dialysis.
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http://dx.doi.org/10.1159/000076854DOI Listing
October 2004

Thermal effects of different dialysis techniques and blood pump speeds: an in vitro study.

J Nephrol 2003 Jul-Aug;16(4):552-7

Department of Nephrology, Maastricht University Hospital, Maastricht, The Netherlands.

Thermal effects have a pivotal impact on hemodynamic stability during dialysis procedures. In contrast to conventional dialysis techniques, there are no data in the literature regarding the thermal energy balance during on-line techniques. Secondly, little data exist on the effect of extracorporeal blood pump speed (EBPS) on thermal energy balance. In this study we assessed, first, relative differences in energy transfer rate (ETR) over the extracorporeal circuit during on-line hemo(dia)filtration (H(D)F) procedures and hemodialysis (HD) at different dialysate temperatures during an in vitro procedure using a blood temperature monitor (BTM). Secondly, we assessed the thermal effects of different blood pump speed (BPS) rates during the various treatment modalities. ETR was different among all treatment modalities (p < 0.05) studied, except for HD at 36.5 degrees C vs. pre-dilution hemofiltration (HF) and post-dilution HDF vs. HD at 37.5 degrees C. ETR had the most negative result, indicating the largest energy loss, during HD at 35.5 degrees C (-58.5.2 +/- 2.6 W), whereas it was almost comparable between pre-dilution HF (-30.7 +/- 4.1 W) and HD at 36.5 degrees C (-35.1.2 +/- 2.4 W). Post-dilution HDF (-17.7 +/- 1.2 W) resulted in an ETR comparable to that of HD at 37.5 degrees C (-15.0 +/- 3.9 W). ETR during post-dilution HF was -43.8 +/- 1.3 W. The thermal effect of the BPS was more pronounced during the procedures with the more negative ETR. In conclusion, on-line techniques and BPS have widely varying effects on ETR during dialysis, which should be considered when the hemodynamic effects among different treatment modalities are compared.
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February 2004

Determinants of arterial distensibility in patients with renal failure.

Nephron Physiol 2003 ;95(3):p43-8

Department of Internal Medicine and Nephrology, University Hospital, Maastricht, The Netherlands.

Background: An increased stiffness of the arterial system is an adverse risk factor for the outcome in patients with renal disease. Few studies have focused on the determinants of an increased arterial stiffness in patients with renal failure. As the percentage of patients with renal failure secondary to vascular disease and/or diabetes mellitus is rapidly growing, and the underlying disease per se may also influence the arterial wall properties, it may also be of interest to study the arterial wall properties in relation to the etiology of kidney disease.

Methods: The distensibility coefficient (DC) of the common carotid artery was used as a marker of arterial stiffness. One hundred and seventeen patients were studied: 47 patients (aged 63 +/- 10 years) with renal failure secondary to vascular disease and/or diabetes mellitus and 70 patients (aged 57 +/- 13 years) with other diagnoses. The origin of the renal failure was retrieved from the patients' charts.

Results: Age, mean arterial pressure, and serum calcium level were each independent predictors of arterial stiffness (DC). The DC was significantly lower in the patients with vascular renal disease or diabetes mellitus [11.0 +/- 5.5 (1/MPa)] as compared with patients with renal/urological diseases [15.4 +/- 7.5 (1/MPa)]. Nevertheless, after correction for potentially confounding variables, the relation between cause of renal disease and DC lost significance in the overall group, but remained significant (p < 0.05) in the younger age groups (
Conclusions: Age, mean arterial pressure, and serum calcium level were independent predictors of arterial stiffness in our patients with renal failure. Only in younger dialysis patients, the origin of renal failure was an independent predictor of arterial wall stiffness.
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http://dx.doi.org/10.1159/000074329DOI Listing
February 2004

Optimizing renal replacement therapy--a case for online filtration therapies?

Nephrol Dial Transplant 2002 Dec;17(12):2065-70

Department of Internal Medicine/Nephrology, University Hospital Maastricht, The Netherlands.

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http://dx.doi.org/10.1093/ndt/17.12.2065DOI Listing
December 2002

A comparison between the soluble transferrin receptor, transferrin saturation and serum ferritin as markers of iron state in hemodialysis patients.

Nephron 2002 Sep;92(1):32-5

Department of Internal Medicine, University Hospital Maastricht, The Netherlands.

An adequate iron management is important in the treatment of anemia and in hemodialysis (HD) patients. Serum ferritin and transferrin saturation (TS) may be influenced by the presence of inflammation. Recently, the soluble transferrin receptor (s-TfR) has been advocated as a parameter of iron status in HD patients. The aim of the present study was to assess firstly the relation between serum ferritin, TS, and s-TfR in HD patients and to predict their agreement (assessed by kappa) in the diagnosis of iron deficiency, and, secondly, to assess the influence of inflammation on the relation between the parameters of iron state. Iron deficiency by either marker was respectively defined as ferritin <100 microg/l, TS <20%, or s-TfR >2.4 microg/ml. In the overall group of patients, TS and s-TfR were significantly related (r = -0.38), whereas s-TfR and serum ferritin were not. Both serum ferritin and TS were related to CRP (r = 0.50 and -0.34; p < 0.05), whereas s-TfR was not. The kappa value for agreement between serum ferritin and TS in the diagnosis of iron deficiency was 0.24 (p = 0.07), 0.12 (p = NS) for the agreement between TS and s-TfR and 0 for that between serum ferritin and s-TfR. In patients with CRP levels
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http://dx.doi.org/10.1159/000064468DOI Listing
September 2002
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