Fluctuation of pre-hemodialysis serum sodium
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INTRODUCTION: Low pre-hemodialysis (pre-HD) serum sodium or hyponatremia is associated with higher mortality. Pre-HD serum sodium can be more stable over time with low fluctuation compared to other serum parameters. MATERIALS AND METHODS: We examined variation of pre-HD serum sodium in 24 months and after this point examined all-cause mortality in a cohort of 261 patients followed-up for 48.8 (standard deviation (SD) = 19.1) months. 6,221 determinations of pre-HD serum sodium were made and corrected for glucose concentrations. Serum sodium was measured pre-HD monthly, and the variability was calculated using the coefficient of variation (CV). RESULTS: The mean age was of 60 ± 14.1 years, 60.9% were men, 48% had diabetes mellitus, and diabetic nephropathy was the most frequent cause of end-stage renal disease. Median CV of sodium in 24 months was 1.7% with a mean of 1.78% (95% CI 1.73 - 1.83). Patients with CV > 1.7% had a higher mortality (53 patients a 36.8%) compared to CV < 1.7% (22 patients a 18.8%) (p = 0.002). In Kaplan-Meier analysis, patients with CV > 1.7% had significantly worse overall survival (log rank = 6.395, p = 0.011). We also stratified the sample in serum sodium tertiles (< 138 mEq/L; 138 - 140 mEq/L; > 140 mEq/L) and made a Kaplan-Meier analysis which showed persistent worse survival outcomes in patients with CV > 1.7% (log rank Mantel-Cox 7.64; p = 0.006). Cox regression multivariate model showed that CV of sodium was significantly associated with overall mortality after adjusting for confounder variables (hazard ratio 2.16, 95% CI 1.37 - 3.41; p = 0.001). CONCLUSION: Variation of pre-HD serum sodium in 2 years is less than a 2%. With the limitations of our study, a higher variability of pre-HD serum sodium in 2 years of treatment (CV > 1.7%) is associated with increased mortality.
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Serum chloride as a marker of cardiovascular and all-cause mortality in chronic hemodialysis patients: 5-Year follow-up study.

BACKGROUND: Hypochloremia has been associated with increased mortality in patients with hypertension, heart failure, sepsis, and chronic kidney disease (CKD). The pathophysiological mechanisms of this finding are not clear. There are no studies describing an association between serum chloride levels (Cl-) and mortality in incident chronic hemodialysis (HD) patients. METHOD: Retrospective cohort study of the incident population in our chronic outpatient hemodialysis program between January 1, 2016, and January 1, 2021 (N=374). Survival time was collected in all patients and analyzed using the Kaplan-Meyer method. A multivariate Cox regression model was performed to predict the probability of survival, applying a stepwise procedure. RESULTS: During the median follow-up period of 20 months, 83 patients died. The 5-year overall survival rate for our patients was 45%. Both natremia and chloremia had no significant differences when compared by sex, vascular access, or etiology. There was an inverse correlation between Cl- and interdialytic weight gain (r=-0.15) (p=0.0038). Patients belonging to the quartile with lower Cl- levels had less probability of survival than patients in the quartile with higher Cl- levels (27% and 68%, respectively, p=0.019). On the other hand, in the multivariate Cox regression model, variables significantly associated with higher mortality were being older, having higher baseline comorbidity by modified Charlson index, not taking diuretics and having lower albumin and chloride levels. Particularly, higher Cl- levels was independently associated with both lower all-cause mortality (adjusted hazard ratio [HR]=0.84; 95% confidence interval [CI], 0.77-0.92; p=0.0001) and cardiovascular mortality (HR 0.9; 95% CI, 0.83-0.97; p<0.0057). CONCLUSIONS: Lower Cl- levels were associated with higher all-cause and cardiovascular mortality in incident patients on chronic hemodialysis in our health area.

Inflammation and hemodialysis adequacy: are C-reactive protein levels influenced by the dose of dialysis?

INTRODUCTION: Chronic inflammation and the underlying cardiovascular comorbidity are still current problems in chronic hemodialysis patients. There are few studies comparing the "dialysis dose" with the degree of inflammation in the patient. Our main objective was to determine whether there is a relationship between serum C-reactive protein (CRP) levels and the "dialysis dose" (Kt / V) using ionic dialysance. METHODS: Multicenter cross-sectional study. 536 prevalent chronic hemodialysis patients were included. CRP levels, neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) were collected. Kt was obtained by ionic dialysance and urea distribution volume was calculated from the Watson's formula. The sample was divided into two groups, taking the median CRP as the cut-off point. Dialysis adequacy obtained in each group was compared. Finally, a logistic regression model was carried out to determine the variables with the greatest influence. RESULTS: Median CRP was 4.10 mg/L (q25-q75: 1.67-10) and mean Kt/V was 1.48 ± 0.308. Kt/V was lower in the patients included in the high inflammation group (p = 0.01). In the multivariate logistic regression, the "high" levels of CRP were directly correlated with the Log INL (p < 0.001) and inversely proportional with serum albumin values (p = 0.014), Kt/V (p = 0.037) and serum iron (p < 0.001). CONCLUSION: The poorer adequacy in terms of dialysis doses, lower Kt / V values, may contribute to a higher degree of inflammation in chronic hemodialysis patients.

Inflammation and hemodialysis adequacy: Are C-reactive protein levels influenced by dialysis dose? / Inflamación y adecuación de la hemodiálisis: ¿están los niveles de proteína C reactiva influidos por la dosis de diálisis recibida?

INTRODUCTION: Chronic inflammation and the underlying cardiovascular comorbidity are still current problems in chronic hemodialysis patients. There are few studies comparing the "dialysis dose" (Kt/V) with the degree of inflammation in the patient. Our main objective was to determine whether there is a relationship between serum C-reactive protein (CRP) levels and the Kt/V using ionic dialysance. METHODS: Multicenter cross-sectional study. A total of 536 prevalent chronic hemodialysis patients were included. CRP levels, neutrophil-lymphocyte ratio and platelet-lymphocyte ratio were collected. Kt was obtained by ionic dialysance and urea distribution volume was calculated from the Watson's formula. The sample was divided into 2 groups, taking the median CRP as the cut-off point. Dialysis adequacy obtained in each group was compared. Finally, a logistic regression model was carried out to determine the variables with the greatest influence. RESULTS: Median CRP was 4.10mg/L (q25-q75: 1.67-10) and mean Kt/V was 1.48±0.308. Kt/V was lower in the patients included in the high inflammation group (P=.01). In the multivariate logistic regression, the "high" levels of CRP were directly correlated with the Log neutrophil-lymphocyte ratio (P<.001) and inversely proportional with serum albumin values (P=.014), Kt/V (P=.037) and serum iron (P<.001). CONCLUSION: The poorer adequacy in terms of dialysis doses (lower Kt/V values) may contribute to a higher degree of inflammation in chronic hemodialysis patients.

Advanced Chronic Kidney Disease Units in Spain: a national survey on standards of structure, resources, results and patient safety. / Unidades de Enfermedad Renal Crónica Avanzada en España: una encuesta nacional sobre los estándares de estructura, recursos, resultados y seguridad del paciente.

BACKGROUND AND OBJECTIVE: Recently, the Advanced Chronic Kidney Disease Units (UERCA, in Spanish) have been developed in Spain to offer a better quality of life to patients with advanced chronic kidney disease (ACKD), improving their survival and reducing morbidity in this phase of the disease. Nowadays, there is not much evidence in the Spanish and international literature regarding the structure and how to achieve these objectives in the UERCA. From the ERCA working group of the Spanish Society of Nephrology (SEN), this project is promoted to improve care for ERCA patients through the definition of quality standards for the operation of the UERCA. MATERIAL AND METHODS: An initial proposal for quality standards concerning the operation of the UERCA was configured through consultation with the main sources of references and the advice of an expert working group through face-to-face and telematic meetings. Base on this initial proposal of standards, a survey was conducted and sent it via email to 121 nephrology specialist and nursing professionals with experience in Spanish UERCA to find out, among others, the suitability of each standards, that is, its mandatory nature or recommendation as standards. The access to the survey was allowed between July 16th, 2018, until September 26th, 2018. RESULTS: A total of 95 (78.5%) professionals participated out of the 121 who were invited to participate. Of these, 80 of the participants were nephrology specialists and 15 nursing professionals, obtaining a varied representation of professionals from the Spanish geography. After analyzing the opinions of these participants, the standards were defined to a total of 68, 37 of them (54.4%) mandatory and 31 of them (45.5%) recommended. Besides, it was observed that the volume of patients attended in the UERCA is usually above 100 patients, and the referral criteria is generally below 25-29 mL/min/1.73 m2 of glomerular filtration. CONCLUSIONS: This work constitutes a first proposal of quality standards for the operation of UERCA in Spain. The definition of these standards has made it possible to establish the bases for the standardization of the organization of UERCA, and to subsequently work on the configuration of a standards manual for the accreditation of ERCA Units.

Classification of Hydration in Clinical Conditions: Indirect and Direct Approaches Using Bioimpedance.

Although the need to assess hydration is well recognized, laboratory tests and clinical impressions are impractical and lack sensitivity, respectively, to be clinically meaningful. Different approaches use bioelectrical impedance measurements to overcome some of these limitations and aid in the classification of hydration status. One indirect approach utilizes single or multiple frequency bioimpedance in regression equations and theoretical models, respectively, with anthropometric measurements to predict fluid volumes (bioelectrical impedance spectroscopy-BIS) and estimate fluid overload based on the deviation of calculated to reference extracellular fluid volume. Alternatively, bioimpedance vector analysis (BIVA) uses direct phase-sensitive measurements of resistance and reactance, measured at 50 kHz, normalized for standing height, then plotted on a bivariate graph, resulting in a vector with length related to fluid content, and direction with phase angle that indexes hydration status. Comparison with healthy population norms enables BIVA to classify (normal, under-, and over-) and rank (change relative to pre-treatment) hydration independent of body weight. Each approach has wide-ranging uses in evaluation and management of clinical groups with over-hydration with an evolving emphasis on prognosis. This review discusses the advantages and limitations of BIS and BIVA for hydration assessment with comments on future applications.

Peritoneal dialysis fluid biocompatibility impact on human peritoneal membrane permeability.

BACKGROUND: We have compared the effects of conventional lactate-based peritoneal dialysis fluid (CPDF) with respect to bicarbonate/lactate-based fluid on peritoneal ultrafiltration (UF) and peritoneal permeability, and on variations on gene expression in cells isolated from effluents of patients' peritoneal bags. METHODS: This was a non-randomized sequential prospective study including all incident peritoneal dialysis (PD) patients (n = 40) recruited in our centre. Peritoneal equilibration tests (PETs) were performed using CPDF or BPDF both containing 2.27% glucose during a 48-h interval in four different sequences. Gene expression variation of selected genes was measured by reverse transcription polymerase chain reaction in mesothelial cells obtained from the total drained fluid during the PET. RESULTS: In the overall study, the use of BPDF was associated with significantly lower mass transfer area coefficient for urea and creatinine, longer accelerated peritoneal examination test times for urea and creatinine, lower total pore area available for exchange over diffusion distance and lower UF. There were no differences in the gene expression of aquaporins 1-3, endothelial and inducible nitric oxide synthase (NOS3 and NOS2), or interleukin-6. The SNAIL and E-CADHERIN gene expression normalized ratio was evaluated in peritoneal effluents of cells obtained from CPDF and BPDF. We observed that the SNAIL/E-CADHERIN mRNA ratio decreased when the dialysis sequence started with BPDF and went on to CPDF, but not when the sequence was the opposite. CONCLUSION: This study shows that those patients who started PD treatment with BPDF were characterized by a better biocompatibility profile. BPDF associates with lower peritoneal permeability to small molecules and lower UF.

Inflamación y adecuación de la hemodiálisis: ¿están los niveles de proteína C reactiva influidos por la dosis de diálisis recibida? / Inflammation and hemodialysis adequacy: Are C-reactive protein levels influenced by dialysis dose?

Introducción : La inflamación crónica y la subyacente comorbilidad cardiovascular aún son problemas vigentes en los pacientes en hemodiálisis crónica. Existen pocos estudios que comparen la «dosis de diálisis» (Kt/V) con el grado de inflamación del paciente. Nuestro objetivo principal fue determinar si existe una relación entre los niveles séricos de proteína C reactiva (PCR) y el Kt/V utilizando la dialisancia iónica.Métodos : Estudio transversal multicéntrico. Se incluyeron 536 pacientes prevalentes en hemodiálisis crónica. Se recogieron los niveles de PCR, el índice neutrófilo-linfocito y el índice plaqueta-linfocito. Se obtuvo el Kt por dialisancia iónica y el volumen de distribución de la urea mediante la fórmula de Watson. Se dividió la muestra en 2 grupos tomando como punto de corte la mediana de PCR y se comparó la adecuación de diálisis en cada uno. Finalmente, se realizó un modelo de regresión logística para determinar las variables de mayor influencia.Resultados : La mediana de PCR fue 4,10mg/L (q25-q75: 1,67-10). El Kt/V medio fue de 1,48±0,308. El Kt/V fue menor en los pacientes incluidos en el grupo de inflamación alta (p=0,01). En la regresión logística multivariante, los niveles «altos» de PCR tuvieron una correlación directa con el Log índice neutrófilo-linfocito (p<0,001) e inversamente proporcional con los valores de albúmina sérica (p=0,014), Kt/V (p=0,037) y hierro sérico (p<0,001).Conclusión : La peor adecuación en términos de dosis de diálisis (valores de Kt/V más bajos) puede contribuir a un mayor grado de inflamación en los pacientes en hemodiálisis crónica. (AU)

Introduction : Chronic inflammation and the underlying cardiovascular comorbidity are still current problems in chronic hemodialysis patients. There are few studies comparing the “dialysis dose” (Kt/V) with the degree of inflammation in the patient. Our main objective was to determine whether there is a relationship between serum C-reactive protein (CRP) levels and the Kt/V using ionic dialysance.Methods : Multicenter cross-sectional study. A total of 536 prevalent chronic hemodialysis patients were included. CRP levels, neutrophil-lymphocyte ratio and platelet-lymphocyte ratio were collected. Kt was obtained by ionic dialysance and urea distribution volume was calculated from the Watson's formula. The sample was divided into 2 groups, taking the median CRP as the cut-off point. Dialysis adequacy obtained in each group was compared. Finally, a logistic regression model was carried out to determine the variables with the greatest influence.Results : Median CRP was 4.10mg/L (q25-q75: 1.67-10) and mean Kt/V was 1.48±0.308. Kt/V was lower in the patients included in the high inflammation group (P=.01). In the multivariate logistic regression, the “high” levels of CRP were directly correlated with the Log neutrophil-lymphocyte ratio (P<.001) and inversely proportional with serum albumin values (P=.014), Kt/V (P=.037) and serum iron (P<.001).Conclusion : The poorer adequacy in terms of dialysis doses (lower Kt/V values) may contribute to a higher degree of inflammation in chronic hemodialysis patients. (AU)

Anaemia and fever in Kidney transplant. The role of human parvovirus B19. / Anemia y fiebre en el postrasplante renal: su relación con el parvovirus humano B19.

Infections remain an issue of particular relevance in renal transplant patients, particularly viral infections. Human parvovirus B19 infection causes severe refractory anaemia, pancytopenia and thrombotic microangiopathy. Its presence is recognized by analysing blood polymerase chain reaction (PCR) and by the discovery of typical giant proerythroblasts in the bone marrow. We report the case of a 65 year-old man with a history of deceased donor renal transplant in September 2014. At 38 days after the transplant, the patient presented progressive anaemia that was resistant to erythropoiesis-stimulating agents. At 64 days after transplant, hyperthermia occurred with progressive deterioration of the patient's general condition. The viral serology and the first blood PCR for human parvovirus B19 were both negative. At 4 months and 19 days after, a bone marrow biopsy was conducted, showing giant erythroblasts with nuclear viral inclusions that were compatible with parvovirus; a PCR in the tissue confirmed the diagnosis. A second blood PCR was positive for parvovirus. After treatment with intravenous immunoglobulin and the temporary discontinuation of mycophenolate mofetil, a complete remission of the disease occurred, although the blood PCR for parvovirus B19 remained positive, so monitoring is necessary for future likely recurrence.