Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 490
Filtrar
1.
PLoS One ; 15(7): e0235135, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32628733

RESUMO

BACKGROUND: In patients on hemodialysis (HD), the various chemical elements in the dialysate may influence survival rates. In particular, calcium modifies mineral and bone metabolism and the vascular calcification rate. We studied the influence of the dialysate calcium concentration and the treatments prescribed for mineral bone disease (MBD) on survival. METHODS: All patients in REIN having initiated HD from 2010 to 2013 were classified according to their exposure to the different dialysate calcium concentrations in their dialysis unit. Data on the individual patients' treatments for MBD were extracted from the French national health database. Cox proportional hazard models were used to estimate mortality hazard ratios (HR) associated with time-dependent exposure to dialysate calcium concentrations and MBD therapies, adjusted for comorbidities, laboratory and technical data. RESULTS: Dialysate calcium concentration of 1.5 mmol/L was used by 81% of the dialysis centers in 2010 and in 83% in 2014. Most centers were using several formulas in up to 78% for 3 formulas in 2010 to 86% in 2014. In full adjusted Cox survival analyses, the percentage of calcium >1.5 mmol/L and <1.5 mmol/l by center and the number of formula used per center were not associated with survival. Depending on the daily dose used, the MBD therapies were associated with survival improvement for calcium, native vitamin D, active vitamin D, sevelamer, lanthanum and cinacalcet in the second and third tertiles of dose. CONCLUSION: No influence of the dialysate calcium concentration was evidenced on survival whereas all MBD therapies were associated with a survival improvement depending on the daily dose used.


Assuntos
Osso e Ossos/efeitos dos fármacos , Cálcio/análise , Soluções para Hemodiálise/análise , Sistema de Registros , Diálise Renal , Insuficiência Renal Crônica/terapia , Idoso , Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/metabolismo , Vasos Sanguíneos/fisiopatologia , Osso e Ossos/metabolismo , Osso e Ossos/fisiopatologia , Calcinose/epidemiologia , Calcinose/metabolismo , Calcinose/fisiopatologia , Cálcio/administração & dosagem , Cálcio/metabolismo , Cinacalcete/análise , Feminino , França/epidemiologia , Soluções para Hemodiálise/administração & dosagem , Soluções para Hemodiálise/química , Humanos , Lantânio/análise , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/mortalidade , Insuficiência Renal Crônica/fisiopatologia , Sevelamer/análise , Vitamina D/análise , Vitamina D/metabolismo
2.
Nefrología (Madrid) ; 39(4): 424-433, jul.-ago. 2019. graf, ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-189764

RESUMO

INTRODUCCIÓN: El líquido de diálisis (LD), elemento esencial en la hemodiálisis (HD), se fabrica in situ mezclando 3 componentes: agua tratada, concentrado de bicarbonato y concentrado ácido. Para evitar la precipitación de carbonato cálcico y magnésico que se produce en el LD por la adición de bicarbonato, es necesario añadir un ácido. Existen 2 concentrados ácidos según contengan acetato (LDA) o citrato (LDC) como estabilizante. OBJETIVO: Comparar el efecto agudo de la HD con LDC vs. LDA sobre el metabolismo del calcio, fosforo y magnesio, el equilibrio ácido base, la coagulación, inflamación y la estabilidad hemodinámica. MÉTODOS: Estudio prospectivo, multicéntrico, aleatorizado y cruzado, de 32 semanas de duración, en pacientes en HD trisemanal, monitor AK-200-Ultra-S o Artis, 16 semanas con LDA SoftPac(R), elaborado con 3 mmol/l de acetato, y 16 semanas con LDC SelectBag Citrate(R), con 1 mmol/l de citrato. Se incluyeron pacientes mayores de 18 años en HD durante un mínimo de 3 meses mediante fístula arteriovenosa. Se recogieron datos epidemiológicos, de diálisis, bioquímica pre- y posdiálisis, episodios de hipotensión arterial, y scores de coagulación mensualmente durante los 8 meses de estudio. Se extrajeron pre- y posdiálisis: gasometría venosa, calcio (Ca), calcio iónico (Cai), fósforo (P), magnesio (Mg) y hormona paratiroidea (PTH), entre otros. ClinicalTrials.gov NCT03319680. RESULTADOS: Se incluyeron 56 pacientes, 47 (84%) hombres y 9 (16%) mujeres de edad media: 65,3 (16,4) años, técnica HD / HDF: 20 (35,7%) / 36 (64,3%). Encontramos diferencias (p < 0,05) cuando utilizamos el LD con citrato (C) frente a acetato (A) en los valores posdiálisis de bicarbonato [C: 26,9 (1,9) vs. A: 28,5 (3) mmol/l], Cai [C: 1,1 (0,05) vs A: 1,2 (0,08) mmol/l], Mg [C. 1,8 (0,1) vs A: 1,9 (0,2) mg/dl] y PTH [C: 255 (172) vs. 148 (149) pg/ml]. No encontramos diferencias en ninguno de los parámetros medidos prediálisis. Se registraron menos episodios de hipotensión arterial durante las sesiones con el LDC; de las 4.416 sesiones de HD, 2.208 en cada grupo, cursaron con hipotensión 311 sesiones (14,1%) con LDA y 238 (10,8%) con LDC (p < 0,01). También fue menor la caída de volumen sanguíneo máximo medido por biosensor Hemoscan(R) [-3,4(7,7) vs. -5,1 (8,2)], aunque sin significación estadística. CONCLUSIÓN: La diálisis con citrato produce de forma aguda menor alcalemia posdiálisis y modifica de forma significativa el Ca, el Mg y la PTH. El LDC tiene un impacto positivo sobre la tolerancia hemodinámica


INTRODUCTION: Dialysis fluid (DF), an essential element in hemodialysis (HD), is manufactured in situ by mixing three components: treated water, bicarbonate concentrate and acid concentrate. To avoid the precipitation of calcium and magnesium carbonate that is produced in DF by the addition of bicarbonate, it is necessary to add an acid. There are 2 acid concentrates that contain acetate (ADF) or citrate (CDF) as a stabilizer. OBJECTIVE: To compare the acute effect of HD with CDF vs. ADF on the metabolism of calcium, phosphorus and magnesium, acid base balance, coagulation, inflammation and hemodynamic stability. METHODS: Prospective, multicenter, randomized and crossed study, of 32 weeks duration, in patients in three-week HD, AK-200-Ultra-S or Artis monitor, 16 weeks with ADF SoftPac(R), prepared with 3mmol/L of acetate, and 16 weeks with CDF SelectBag Citrate(R), with 1mmol/L of citrate. Patients older than 18 years were included in HD for a minimum of 3 months by arteriovenous fistula. Epidemiological, dialysis, pre and postdialysis biochemistry, episodes of arterial hypotension, and coagulation scores were collected monthly during the 8 months of the study. Pre and post-dialysis analysis were extracted: venous blood gas, calcium (Ca), ionic calcium (Cai), phosphorus (P), magnesium (Mg) and parathyroid hormone (PTH) among others. ClinicalTrials.gov NCT03319680. RESULTS: We included 56 patients, 47 (84%) men and 9 (16%) women, mean age: 65.3 (16.4) years, technique HD / HDF: 20 (35.7%) / 36 (64.3%). We found differences (p < 0.05) when using the DF with citrate (C) versus acetate (A) in the postdialysis values of bicarbonate [C: 26.9 (1.9) vs. A: 28.5 (3) mmol/L], Cai [C: 1.1 (0.05) vs. A: 1.2 (0.08) mmol/L], Mg [C: 1.8 (0.1) vs A: 1, 9 (0.2) mg/dL] and PTH [C: 255 (172) vs. 148 (149) pg/mL]. We did not find any differences in any of the parameters measured before dialysis. Of the 4,416 sessions performed, 2,208 in each group, 311 sessions (14.1%) with ADF and 238 (10.8%) with CDF (p < 0.01), were complicated by arterial hypotension. The decrease in maximum blood volume measured by Hemoscan(R) biosensor was also lower [-3.4 (7.7) vs -5.1 (8.2)] although without statistical significance. CONCLUSION: Dialysis with citrate acutely produces less postdialysis alkalemia and significantly modifies Ca, Mg and PTH. CDF has a positive impact on hemodynamic tolerance


Assuntos
Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Acetatos/administração & dosagem , Citratos/administração & dosagem , Soluções para Hemodiálise/química , Diálise Renal/métodos , Estudos Cross-Over , Estudos Prospectivos , Resultado do Tratamento
3.
Iran J Kidney Dis ; 13(2): 113-119, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30988248

RESUMO

INTRODUCTION: Hepcidin is a key regulator of iron homeostasis, takes part in pathophysiology of anemia and cardiovascular disease in maintenance hemodialysis (MHD) patients. The aim of this study was to compare the effect of glucose-free and glucose-containing dialysate on the clearance of hepcidin-25 during a hemodialysis (HD) session and discuss its potential mechanism in MHD patients. METHODS: In a longitudinal interventional study of 30 stable MHD patients without diabetes, we measured serum hepcidin-25 and plasma catecholamines (adrenaline, noradrenaline, and dopamine) during HD session using glucose-free dialysate and then switched to 5.55 mmol/L glucose-containing dialysate. One-way analysis of variance (ANOVA) was used to identify the effect of two dialysates on the intra-dialysis changes of hepcidin-25 and catecholamines. Spearman and Pearson correlation coefficients were performed to detect the relationships between hepcidin-25 and catecholamines. RESULTS: Glucose-free dialysate achieved a greater reduction of hepcidin-25 than 5.55 mmol/L glucose-containing dialysate in a single bicarbonate HD session [-8.43 (-15.44 to -1.42) vs. 0.46 (-6.09 to 7.00) %, P < .05]. The intra-dialysis changes of catecholamines showed no significant differences between the two dialysates. The serum hepcidin-25 levels were positively associated with plasma catecholamines levels at pre-, intra- and post-HD (R = 0.22~0.62 with P < .05). CONCLUSIONS: Our findings suggest that glucose-containing dialysate might up-regulate hepcidin-25 synthesis through activation of the sympathetic nervous system or oxidative stress, possibly mediated by increased production of catecholamines. Adequately designed studies are needed to confirm and reveal the mechanisms of dialysate glucose concentration on hepcidin-25 kinetics during HD sessions.


Assuntos
Glucose/uso terapêutico , Soluções para Hemodiálise/uso terapêutico , Hepcidinas/farmacocinética , Falência Renal Crônica/terapia , Diálise Renal/efeitos adversos , Adulto , Bicarbonatos , Diabetes Mellitus , Feminino , Soluções para Hemodiálise/química , Humanos , Cinética , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade
4.
Perit Dial Int ; 39(2): 187-190, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30858288

RESUMO

Whilst antibiotic lock is effective to eradicate biofilm bacteria on hemodialysis catheters, this adjunctive method has scarcely been tested in peritoneal dialysis (PD) patients. After our previous successful experience of its use to salvage two Tenckhoff catheters, we encountered another patient with problematic biofilm-associated PD peritonitis who strongly refused catheter removal. As a result, antibiotic lock was given once daily, initially, with continuation of the usual PD schedule. However, relapsing peritonitis could not be prevented until we administered antibiotic lock without dialysate in the abdomen, which led to successful eradication of biofilm bacteria. To investigate the significance of having "dry abdomen" during antibiotic lock treatment, we injected an equivalent amount of contrast into the Tenckhoff catheter under fluoroscopy. We observed that the catheter lock solution could be retained over a long period of time only with "dry abdomen," whereas rapid dissipation of the lock solution occurred in the presence of dialysate. We concluded that whilst antibiotic lock in a once-daily regimen can be highly effective against biofilm bacteria on a Tenckhoff catheter, it is essential to withhold PD exchanges during the dwell of antibiotic lock to prevent it from dissolving into the surrounding dialysate.


Assuntos
Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Infecções Relacionadas a Cateter/microbiologia , Infecções Relacionadas a Cateter/prevenção & controle , Cateteres de Demora , Diálise Peritoneal/instrumentação , Peritonite/microbiologia , Peritonite/prevenção & controle , Antibacterianos/análise , Soluções para Hemodiálise/química , Humanos
5.
Blood Purif ; 47(4): 351-360, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30562731

RESUMO

BACKGROUND AND OBJECTIVES: While trying to optimize the dialysis clearances of protein-bound uremic toxins (PBUTs), their percentage protein binding (% PB) is an important parameter. We evaluated the effects of ionic strength, pH change and chemical displacers on the dissociation of PBUTs from albumin in vitro. METHODS: PBUTs, such as 3-Carboxy-4-methyl-5-propyl-2-furan-propanoic acid (CMPF), p-cresylsulfate (PCS), indoxyl sulfate (IS) and indole-3-acetic acid (IAA), were spiked with human serum albumin (HSA) solution prepared with different Nacl concentrations and pH values or in the presence of a series of chemical displacers. Ultrafiltration was performed to separate the free and bound fractions, and the % PB of each PBUT was calculated. RESULTS: For all 4 compounds, their % PB decreased with increasing ionic strength, while only slight changes occurred when the pH of the test solution increased from pH 6.0 to pH 8.5; PCS, IS and 3-IAA were relatively easily dissociated from albumin by drug displacement, while CMPF was released from HSA by all studied drugs with difficulty; the PB % for CMPF, PCS, IS and 3-IAA decreased most remarkably in the presence of free fatty acids, such as oleic acid (41.73% for CMPF, 29.9% for PCS, 23.22% for IS, and 20.34% for 3-IAA) and linoleic acid (43.12% for CMPF, 16.65% for PCS, 29.99% for IS, and 16.29% for 3-IAA). CONCLUSION: The protein binding of PBUTs can be decreased by higher ionic strength, increased pH and the presence of some chemical displacers, including free fatty acids. Effective dialytic removal of PBUTs may be achieved by applying these methods jointly to blood-purification techniques.


Assuntos
Proteínas Sanguíneas/química , Soluções para Hemodiálise/química , Concentração de Íons de Hidrogênio , Concentração Osmolar , Toxinas Biológicas/química , Proteínas Sanguíneas/metabolismo , Cromatografia Líquida de Alta Pressão , Humanos , Ligação Proteica , Albumina Sérica/química , Albumina Sérica/metabolismo , Toxinas Biológicas/metabolismo , Uremia
6.
Ther Apher Dial ; 23(2): 153-159, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30381891

RESUMO

Blood pressure variability is an independent risk factor for mortality and cardiovascular events in hemodialysis patients. Dialysate sodium concentration may not only have effects on blood pressure but also on blood pressure variability. We investigated whether dialysate sodium concentration lowering could decrease home blood pressure variability in hemodialysis patients. Forty-three hemodialysis patients at their dry weight assessed by bioimpedance methods with pre-dialysis serum sodium >136 mmol/L were recruited. Firstly, patients underwent a 1-month standard dialysis with dialysate sodium concentration of 138 mmol/L, and then the dialysate sodium concentration was decreased to 136 mmol/L for 8 weeks. Home blood pressure was assessed on waking up and at bedtime for 1 week. Coefficient of variation was used to define home blood pressure variability. After the intervention, whole-day systolic blood pressure variability decreased from 5.7 ± 2.6% to 4.3 ± 1.7% and evening systolic blood pressure variability decreased from 7.9 ± 4.1% to 6.2 ± 3.1%. Morning systolic blood pressure variability had a reduction from 7.8 ± 2.4% to 5.9 ± 3.3% but did not achieve statistical significance (P = 0.077). Whole-day, morning and evening systolic blood pressure were decreased significantly. Less changes were observed in diastolic blood pressure parameters. Interdialytic weight gain mildly but significantly decreased. Volume parameters, dietary sodium intake and incidence of adverse events were similar throughout the study period. Lowering dialysate sodium concentration could improve home blood pressure variability among hemodialysis patients who had achieved their dry weight.


Assuntos
Pressão Sanguínea/fisiologia , Soluções para Hemodiálise/química , Diálise Renal/métodos , Sódio/química , Adulto , Idoso , Determinação da Pressão Arterial/métodos , Impedância Elétrica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores de Tempo , Ganho de Peso/fisiologia
8.
Semin Nephrol ; 38(6): 570-581, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30413252

RESUMO

In the United States, end-stage renal disease patients receiving hemodialysis have an exceedingly high risk of sudden cardiac death (SCD), accounting for 29% of death events, likely relating to their uremic milieu, recurring exposure to fluid and electrolyte fluxes, and underlying cardiovascular pathology. Furthermore, epidemiologic studies have shown that SCD events, as well as mortality and hospitalizations, occur most frequently on the first dialysis day after the long interdialytic gap, suggesting that abrupt fluctuations in the accumulation and removal of electrolytes, fluid, and uremic toxins over the dialysis cycle may be contributory. Some population-based observational studies have suggested that lower dialysate potassium concentrations appear to be associated with a heightened risk of postdialysis cardiac arrest in hemodialysis patients, although the optimal serum-to-dialysate potassium gradient remains unclear. Some observational studies have suggested that low dialysate calcium concentrations and high serum-to-dialysate calcium gradients may predispose patients to SCD. There is ongoing controversy about an association between higher dialysate bicarbonate concentrations and higher risk of cardiac arrest, likely owing to confounding by indication. Some observational studies also have shown that large interdialytic weight gains, fluid retention, and high ultrafiltration rates are linked with higher risk of SCD and mortality. However, there remains considerable controversy regarding the pros and cons of designating a specific upper ultrafiltration limit with extended treatment times as a clinical practice measure, and further studies are needed to define the optimal tools, metrics, targets, and implementation measures for volume control in the hemodialysis population. In this review, we highlight the epidemiology and pathophysiology of how specific aspects of the hemodialysis procedure may relate to the risk of SCD, as well as preventative strategies and future research directions that can address this risk.


Assuntos
Morte Súbita Cardíaca/epidemiologia , Soluções para Hemodiálise/química , Falência Renal Crônica/terapia , Potássio/sangue , Diálise Renal/efeitos adversos , Desequilíbrio Ácido-Base/sangue , Bicarbonatos/administração & dosagem , Bicarbonatos/análise , Cálcio/administração & dosagem , Cálcio/análise , Morte Súbita Cardíaca/prevenção & controle , Soluções para Hemodiálise/administração & dosagem , Humanos , Magnésio/administração & dosagem , Magnésio/análise , Potássio/administração & dosagem , Potássio/análise , Diálise Renal/métodos , Fatores de Tempo , Equilíbrio Hidroeletrolítico
9.
Semin Dial ; 31(6): 563-568, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30343516

RESUMO

The concentration of sodium in dialysis fluid, a major determinant of extracellular fluid volume and blood pressure, plays a major role in the sodium balance in end-stage renal disease patients. A low dialysate sodium concentration (DNa) reduces interdialytic weight gain (IDWG) and blood pressure and might help ameliorate endothelial dysfunction and inflammation. However, low DNa can also increase the incidence of hypotensive episodes and muscle cramps. Sodium profiling, as typically prescribed in which the DNa is ramped up from above 140 mEq/L to nonphysiological levels, might reduce hypotension in patients with hemodynamic instability but at the cost of the consequences of hypernatremia. Serum sodium concentrations of individual patients fall within a narrow range around a "sodium setpoint." The sodium gradient, the difference between the sodium set point and the DNa, is associated more robustly with clinical outcomes than DNa itself. Sodium concentration presents several issues: the influence of the net negative charge of plasma proteins on sodium flux across the dialysis membrane (Donnan equilibrium); and the clinically important problems in measuring sodium levels. This article presents a review of the clinical effects of DNa and of basic aspects of sodium balance in hemodialysis patients.


Assuntos
Soluções para Hemodiálise/química , Falência Renal Crônica/terapia , Diálise Renal/efeitos adversos , Sódio/metabolismo , Pressão Sanguínea , Soluções para Hemodiálise/efeitos adversos , Humanos , Ganho de Peso
10.
Semin Dial ; 31(6): 569-575, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30027592

RESUMO

Nephrologists are faced with a difficult dilemma in choosing the ideal dialysis prescription to maintain neutral potassium mass balance. Should potassium mass balance goals prioritize the normalization of serum potassium levels using low potassium dialysate at the expense of provoking intradialytic arrhythmias, or should mass balance goals favor permissive hyperkalemia using higher dialysate potassium to avoid rapid intradialytic fluxes at the risk of more interdialytic arrhythmias? This review examines the factors that determine potassium mass balance among HD patients, the relationships between serum and dialysate potassium levels and outcomes, and concludes by examining currently available approaches to reducing risk of arrhythmias while managing potassium mass balance.


Assuntos
Arritmias Cardíacas/etiologia , Soluções para Hemodiálise/química , Falência Renal Crônica/terapia , Potássio/metabolismo , Diálise Renal/efeitos adversos , Arritmias Cardíacas/prevenção & controle , Eletrofisiologia , Soluções para Hemodiálise/efeitos adversos , Humanos , Potássio/sangue , Fatores de Risco
11.
Biosci Rep ; 38(3)2018 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-29871973

RESUMO

Peritonitis is still a major cause of the death in peritoneal dialysis (PD) patients despite the significant decline of the peritonitis rates in recent years. The present study is designed to evaluate the therapeutic potential of peroxisome proliferator-activated receptor-γ agonist, rosiglitazone, on the structure and function of the peritoneum in a PD rat accompanied with peritonitis induced by lipopolysaccharide (LPS). Our data showed that the peritoneal membrane in the LPS-only group showed increased peritoneal thickness, vessel density, and hypercellularity compared with the PD-only group. Rosiglitazone administration significantly inhibited increase of the three indicators in PD rats with LPS treatment. In line with this, rosiglitazone improved function of the peritoneum in LPS-induced PD rats receiving rosiglitazone, which was reflected by decreased D/P urea and D/P albumin. Mechanistically, rosiglitazone-mediated improvements in the damaged structure and function of the peritoneum in PD rats with LPS treatment were associated with reduced inflammation and preserving mesothelial cell monolayer resulted from up-regulation of AQP-1 and ZO-1. Our findings thus suggest that peroxisome proliferator-activated receptor γ (PPAR-γ) activation might be a reasonable strategy to prevent and ameliorate peritoneal deterioration in PD patients, especially with peritonitis.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Aquaporina 1/agonistas , PPAR gama/agonistas , Diálise Peritoneal , Peritonite/tratamento farmacológico , Rosiglitazona/farmacologia , Albuminúria/induzido quimicamente , Albuminúria/tratamento farmacológico , Albuminúria/genética , Albuminúria/patologia , Animais , Aquaporina 1/genética , Aquaporina 1/metabolismo , Regulação da Expressão Gênica , Soluções para Hemodiálise/química , Lipopolissacarídeos , Masculino , PPAR gama/genética , PPAR gama/metabolismo , Peritônio/irrigação sanguínea , Peritônio/efeitos dos fármacos , Peritônio/metabolismo , Peritônio/patologia , Peritonite/induzido quimicamente , Peritonite/genética , Peritonite/patologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais , Ureia/sangue , Proteína da Zônula de Oclusão-1/genética , Proteína da Zônula de Oclusão-1/metabolismo
12.
Semin Dial ; 31(6): 576-582, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29885083

RESUMO

Acid-base equilibrium is a complex and vital system whose regulation is impaired in chronic kidney disease (CKD). Metabolic acidosis is a common complication of CKD. It is typically due to the accumulation of sulfate, phosphorus, and organic anions. Metabolic acidosis is correlated with several adverse outcomes, such as morbidity, hospitalization and mortality. In patients undergoing hemodialysis, acid-base homeostasis depends on many factors: net acid production, amount of alkali given by the dialysate bath, duration of interdialytic period, as well as residual diuresis, if any. Recent literature data suggest that the development of postdialysis metabolic alkalosis may contribute to adverse clinical outcomes. Unfortunately, no randomized studies exist about the effect of different dialysate bicarbonate concentrations on hard outcomes, such as mortality. Like everything else in dialysis, the quest for the "ideal" dialysate bicarbonate concentration is far from over. The Latin aphorism "ne quid nimis" ie "nothing in excess" (excess of neither acid nor base) probably best summarizes our current state of knowledge in this field. For the present, the clinician should understand that target values for predialysis serum bicarbonate concentrations have been established primarily based on observational studies and expert opinion. On the basis of this information, we should keep predialysis serum bicarbonate concentrations at least at 22 mEq/L. Furthermore, a specific focus should be addressed to the clinical and nutritional status of the major outliers on both the acid and alkaline sides of the curve.


Assuntos
Acidose/etiologia , Bicarbonatos/metabolismo , Soluções para Hemodiálise/química , Falência Renal Crônica/terapia , Diálise Renal/efeitos adversos , Equilíbrio Ácido-Base/fisiologia , Acidose/mortalidade , Bicarbonatos/sangue , Soluções para Hemodiálise/efeitos adversos , Humanos , Falência Renal Crônica/complicações , Diálise Renal/mortalidade , Fatores de Risco , Taxa de Sobrevida
13.
Ther Apher Dial ; 22(5): 503-508, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29923680

RESUMO

Although the Kidney Disease Improving Global Outcomes (KDIGO) guidelines recommend a dialysate calcium concentration between 2.5 and 3.0 mEq/L, its optimal concentration remains unclear. A total of 53 hemodialysis patients with intact parathyroid hormone (PTH) levels <150 pg/mL were enrolled in this prospective observational study. A dialysate calcium concentration was converted from 3.0 to 2.75 mEq/L and bone metabolic markers including bone alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase-5b (TRACP-5b) were examined. After 3 months, serum corrected calcium levels decreased (P < 0.001), while serum intact PTH, BAP and TRACP-5b levels increased (P < 0.05, P < 0.05 and P < 0.001, respectively). Multiple regression analyses showed that the amount of change in BAP was significantly associated with dialysis vintage (P < 0.01). In conclusion, the lowering of dialysate calcium concentration stimulated parathyroid gland and bone remodeling in hemodialysis patients with suppressed PTH, particularly with longer dialysis vintage.


Assuntos
Cálcio/administração & dosagem , Soluções para Hemodiálise/química , Hormônio Paratireóideo/sangue , Diálise Renal/métodos , Idoso , Fosfatase Alcalina/sangue , Remodelação Óssea/fisiologia , Cálcio/química , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Glândulas Paratireoides/metabolismo , Estudos Prospectivos , Análise de Regressão , Fosfatase Ácida Resistente a Tartarato/sangue
14.
Semin Dial ; 31(5): 468-478, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29813184

RESUMO

In patients receiving hemodialysis, it has long been recognized that much more bicarbonate is delivered during treatment than ultimately appears in the blood. To gain insight into this mystery, we developed a model that allows a quantitative analysis of the patient's response to rapid alkalinization during hemodialysis. Our model is unique in that it is based on the distribution of bicarbonate in the extracellular fluid and assesses its removal from this compartment by mobilization of protons (H+ ) from buffers and other sources. The model was used to analyze the pattern of rise in blood bicarbonate concentration ([HCO3- ]), calculated from measurements of pH and PCO2 , in patients receiving standard bicarbonate hemodialysis. Model analysis demonstrated two striking findings: (1) 35% of the bicarbonate added during hemodialysis was due to influx and metabolism of acetate, despite its low concentration in the bath solution, because of the rapidly collapsing gradient for bicarbonate influx. (2) Almost 90% of the bicarbonate delivered to the patients was neutralized by H+ generation. Virtually all the new H+ came from intracellular sources and included both buffering and organic acid production. The small amount of added bicarbonate retained in the extracellular fluid increased blood [HCO3- ], on average, by 6 mEq/L in our patients. Almost all this rise occurred during the first 2 hours. Thereafter, blood [HCO3- ] changed minimally and always remained less than bath [HCO3- ]. This lack of equilibrium was due to the continued production of organic acid. Release of H+ from buffers is a reversible physiological response, restoring body alkali stores. By contrast, organic acid production is an irreversible process during hemodialysis and is metabolically inefficient and potentially catabolic. Our analysis underscores the need to develop new approaches for alkali repletion during hemodialysis that minimize organic acid production.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Bicarbonatos/metabolismo , Homeostase/fisiologia , Diálise Renal/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Líquido Extracelular/metabolismo , Feminino , Soluções para Hemodiálise/química , Humanos , Falência Renal Crônica/fisiopatologia , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Modelos Teóricos
15.
Sci Rep ; 8(1): 254, 2018 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-29321509

RESUMO

Recent studies have revealed unique biological characteristics of molecular hydrogen (H2) as an anti-inflammatory agent. We developed a novel haemodialysis (E-HD) system delivering an H2 (30-80 ppb)-enriched dialysis solution by water electrolysis, and conducted a non-randomized, non-blinded, prospective observational study exploring its clinical impact. Prevalent chronic HD patients were allocated to either the E-HD (n = 161) group or the conventional HD (C-HD: n = 148) group, and received the respective HD treatments during the study. The primary endpoint was a composite of all-cause mortality and development of non-lethal cardio-cerebrovascular events (cardiac disease, apoplexy, and leg amputation due to peripheral artery disease). During the 3.28-year mean observation period, there were no differences in dialysis parameters between the two groups; however, post-dialysis hypertension was ameliorated with significant reductions in antihypertensive agents in the E-HD patients. There were 91 events (50 in the C-HD group and 41 in the E-HD group). Multivariate analysis of the Cox proportional hazards model revealed E-HD as an independent significant factor for the primary endpoint (hazard ratio 0.59; [95% confidence interval: 0.38-0.92]) after adjusting for confounding factors (age, cardiovascular disease history, serum albumin, and C-reactive protein). HD applying an H2-dissolved HD solution could improve the prognosis of chronic HD patients.


Assuntos
Soluções para Hemodiálise , Hidrogênio , Diálise Renal/métodos , Insuficiência Renal/terapia , Idoso , Biomarcadores , Feminino , Soluções para Hemodiálise/química , Humanos , Hidrogênio/química , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Estudos Prospectivos , Diálise Renal/efeitos adversos , Insuficiência Renal/diagnóstico , Insuficiência Renal/etiologia , Insuficiência Renal/mortalidade , Fatores de Risco , Resultado do Tratamento
16.
Math Med Biol ; 35(suppl_1): 87-120, 2018 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-29059342

RESUMO

Calcium has two important roles in haemodialysis. It participates in the activation of blood coagulation and calcium intakes have a major impact on patient mineral and bone metabolism. The aim of this article is to propose a mathematical model for calcium ions concentration in a dialyzer during haemodialysis using a citrate dialysate. The model is composed of two elements. The first describes the flows of blood and dialysate in a dialyzer fibre. It was obtained by asymptotic analysis and takes into account the anisotropy of the fibres forming a dialyzer. Newtonian and non-Newtonian blood rheologies were tested. The second part of the model predicts the evolution of the concentration of five chemical species present in these fluids. The fluid velocity field drives the convective part of a convection-reaction-diffusion system that models the exchange of free and complexed calcium. We performed several numerical experiments to calculate the free calcium concentration in the blood in a dialyzer using dialysates with or without citrate. The choice of blood rheology had little effect on the fluid velocity field. Our model predicts that only a citrate based dialysate without calcium can decrease free calcium concentration at the blood membrane interface low enough to inhibit blood coagulation. Moreover for a given calcium dialysate concentration, adding citrate to the dialysate decreases total calcium concentration in the blood at the dialyzer outlet. This decrease of the calcium concentration can be compensated by infusing in the dialyzed blood a quantity of calcium computed from the model.


Assuntos
Cálcio/metabolismo , Ácido Cítrico/química , Soluções para Hemodiálise/química , Modelos Biológicos , Diálise Renal/métodos , Algoritmos , Coagulação Sanguínea , Cálcio/sangue , Simulação por Computador , Hemorreologia , Humanos , Transporte de Íons , Conceitos Matemáticos , Diálise Renal/estatística & dados numéricos
17.
Nefrologia ; 38(2): 161-168, 2018.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-29198593

RESUMO

BACKGROUND: Online haemodiafiltration (OL-HDF) is currently the most effective dialysis technique that also improves survival. To date, high permeability membranes with low albumin loss, such as polysulfone, polyamide and polyacrylonitrile membranes have been the most widely used. However, the initially restricted use of cellulose triacetate (CTA) membranes in OL-HDF has expanded. The aim of the study was to ascertain whether the latest generation asymmetric CTA membranes are more effective in obtaining high convective transport. PATIENTS AND METHODS: A total of 16 patients (10 males and 6 females) undergoing OL-HDF were studied. Each patient underwent 4 different sessions, with haemodialysis or OL-HDF, and/or with CTA or asymmetric CTA 1.9 m2 membranes. Each session was assigned in a randomised order. Serum levels of urea, creatinine, ß2-microglobulin, myoglobin, prolactin, α1-microglobulin, α1-acid glycoprotein and albumin where measured at the beginning and end of each session to obtain the reduction rate. The loss of solutes and albumin was quantified from the dialysate. RESULTS: A significantly greater replacement volume in OL-HDF (32.1±3.1 vs. 19.7±4.5 l, P<.001) was obtained by using asymmetrical CTA membranes compared to conventional CTA membranes. Regarding uraemic toxin removal, both membranes obtained similar results for small molecules, whereas asymmetric CTA membranes achieved better results for large molecules, increasing the reduction ratio by 29% for ß2-microglobulin, 27.7% for myoglobin, 19.5% for prolactin, 49% for α1-microglobulin and double for α1-acid glycoprotein (P<0.001 in all situations). The loss of albumin was less than 2g for all treatment sessions. CONCLUSION: Latest-generation asymmetric CTA have proven to be effective in attaining OL-HDF objectives without increased albumin loss.


Assuntos
Celulose/análogos & derivados , Hemodiafiltração/instrumentação , Falência Renal Crônica/terapia , Membranas Artificiais , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Creatinina/análise , Desenho de Equipamento , Feminino , Hemodiafiltração/métodos , Soluções para Hemodiálise/química , Humanos , Falência Renal Crônica/sangue , Masculino , Pessoa de Meia-Idade , Mioglobina/análise , Orosomucoide/análise , Prolactina/análise , Diálise Renal/instrumentação , Toxinas Biológicas/análise , Microglobulina beta-2/análise
18.
PLoS One ; 12(11): e0188045, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29155846

RESUMO

CD40/CD40 ligand (CD40L) dyad, a co-stimulatory bi-molecular complex involved in the adaptive immune response, has also potent pro-inflammatory actions in haematopoietic and non-haematopoietic cells. We describe here a novel role for soluble CD40L (sCD40L) as modifier of glomerular permselectivity directly acting on glomerular epithelial cells (GECs). We found that stimulation of CD40, constitutively expressed on GEC cell membrane, by the sCD40L rapidly induced redistribution and loss of nephrin in GECs, and increased albumin permeability in isolated rat glomeruli. Pre-treatment with inhibitors of CD40-CD40L interaction completely prevented these effects. Furthermore, in vivo injection of sCD40L induced a significant reduction of nephrin and podocin expression in mouse glomeruli, although no significant increase of urine protein/creatinine ratio was observed after in vivo injection. The same effects were induced by plasma factors partially purified from post-transplant plasma exchange eluates of patients with focal segmental glomerulosclerosis (FSGS), and were blocked by CD40-CD40L inhibitors. Moreover, 17 and 34 kDa sCD40L isoforms were detected in the same plasmapheresis eluates by Western blotting. Finally, the levels of sCD40Lwere significantly increased in serum of children both with steroid-sensitive and steroid-resistant nephrotic syndrome (NS), and in adult patients with biopsy-proven FSGS, compared to healthy subjects, but neither in children with congenital NS nor in patients with membranous nephropathy. Our results demonstrate that sCD40L directly modifies nephrin and podocin distribution in GECs. Moreover, they suggest that sCD40L contained in plasmapheresis eluates from FSGS patients with post-transplant recurrence may contribute, presumably cooperating with other mediators, to FSGS pathogenesis by modulating glomerular permeability.


Assuntos
Antígenos CD40/genética , Ligante de CD40/genética , Glomerulonefrite Membranosa/metabolismo , Glomerulosclerose Segmentar e Focal/metabolismo , Glomérulos Renais/metabolismo , Síndrome Nefrótica/metabolismo , Adolescente , Corticosteroides/uso terapêutico , Adulto , Albuminas/genética , Albuminas/metabolismo , Animais , Antígenos CD40/metabolismo , Ligante de CD40/metabolismo , Ligante de CD40/farmacologia , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/patologia , Permeabilidade da Membrana Celular , Criança , Pré-Escolar , Citotoxinas/uso terapêutico , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Regulação da Expressão Gênica , Glomerulonefrite Membranosa/tratamento farmacológico , Glomerulonefrite Membranosa/genética , Glomerulonefrite Membranosa/patologia , Glomerulosclerose Segmentar e Focal/genética , Glomerulosclerose Segmentar e Focal/patologia , Glomerulosclerose Segmentar e Focal/cirurgia , Soluções para Hemodiálise/química , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Glomérulos Renais/efeitos dos fármacos , Glomérulos Renais/patologia , Transplante de Rim , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Síndrome Nefrótica/tratamento farmacológico , Síndrome Nefrótica/genética , Síndrome Nefrótica/patologia , Troca Plasmática , Plasmaferese , Ratos
19.
PLoS One ; 12(10): e0186010, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29016645

RESUMO

BACKGROUND AND AIM: Numerous outcome studies and interventional trials in hemodialysis (HD) patients are based on uremic toxin concentrations determined at one single or a limited number of time points. The reliability of these studies however entirely depends on how representative these cross-sectional concentrations are. We therefore investigated the variability of predialysis concentrations of uremic toxins over time. METHODS: Prospectively collected predialysis serum samples of the midweek session of week 0, 1, 2, 3, 4, 8, 12, and 16 were analyzed for a panel of uremic toxins in stable chronic HD patients (N = 18) while maintaining dialyzer type and dialysis mode during the study period. RESULTS: Concentrations of the analyzed uremic toxins varied substantially between individuals, but also within stable HD patients (intra-patient variability). For urea, creatinine, beta-2-microglobulin, and some protein-bound uremic toxins, Intra-class Correlation Coefficient (ICC) was higher than 0.7. However, for phosphorus, uric acid, symmetric and asymmetric dimethylarginine, and the protein-bound toxins hippuric acid and indoxyl sulfate, ICC values were below 0.7, implying a concentration variability within the individual patient even exceeding 65% of the observed inter-patient variability. CONCLUSION: Intra-patient variability may affect the interpretation of the association between a single concentration of certain uremic toxins and outcomes. When performing future outcome and interventional studies with uremic toxins other than described here, one should quantify their intra-patient variability and take into account that for solutes with a large intra-patient variability associations could be missed.


Assuntos
Soluções para Hemodiálise/química , Diálise Renal , Insuficiência Renal Crônica/terapia , Toxinas Biológicas/análise , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Arginina/análogos & derivados , Arginina/análise , Creatinina/análise , Feminino , Hipuratos/análise , Humanos , Indicã/análise , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Fósforo/análise , Ureia/análise , Ácido Úrico/análise , Microglobulina beta-2/análise
20.
Braz J Med Biol Res ; 50(12): e6145, 2017 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-29069222

RESUMO

Chronic systemic inflammation and repetitive damage of vascular endothelia by incompatible dialysis system are probable causes of cardiovascular disease in patients on dialysis. The present study aimed to assess in vitro biocompatibility and anti-inflammatory effect of hemodialysis fluid supplemented with rosmarinic acid (RA) using human umbilical vein endothelial cells (HUVEC). HUVECs (5×106 cells/mL) were pre-exposed to 1 µg/mL of lipopolysaccharides (LPS) and incubated with RA-supplemented hemodialysis fluid (HDF). Cytotoxicity was assessed qualitatively by morphologic assessment and quantitatively by MTT assay. Expressions of proinflammatory mediators were assessed using quantitative real-time PCR and production of NO was quantified. Phosphorylation of AKT and nuclear localization of nuclear factor kappa B (NF-κB) were examined using western blotting. Exposure of HUVECs to RA-supplemented HDF had no influence on morphology and viability. Inhibition of proinflammatory mediator production in HUVECs by RA supplementation to HDF was significant in a dose-dependent manner. Exposure to RA-supplemented HDF resulted in a decrease in nitric oxide synthase expression and reduction of NO production in LPS-stimulated HUVECs. RA supplementation of HDF suppressed Akt activation in LPS-stimulated HUVECs. In addition, the level of cellular IκB was increased in parallel to a reduced nuclear translocation of NF-κB in LPS-induced endothelial cells. Our results suggest that RA-supplemented HDF is biocompatible and significantly suppressed inflammation induced in endothelial cells. In this respect, the use of HDF supplemented with RA could alleviate inflammation and improve long-term treatment of patients with renal failure on dialysis. Further clinical studies are required to confirm the effects.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Materiais Biocompatíveis/farmacologia , Cinamatos/farmacologia , Depsídeos/farmacologia , Soluções para Hemodiálise/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Inflamação/tratamento farmacológico , Análise de Variância , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Citocinas/análise , Citocinas/efeitos dos fármacos , Formazans , Soluções para Hemodiálise/química , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Immunoblotting , Inflamação/metabolismo , Lipopolissacarídeos , NF-kappa B/análise , Óxido Nítrico/análise , Fosforilação , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Sais de Tetrazólio
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA