Blood stream Infections in chronic hemodialysis patients - characteristics and outcomes.

INTRODUCTION: Bloodstream Infections (BSI) are a major cause of death and hospitalization among hemodialysis (HD) patients. The rates of BSI among HD patients vary and are influenced by local patient and pathogen characteristics. Modifications in local infection prevention protocols in light of active surveillance of BSI has been shown to improve clinical outcomes. The aim of this study was to further explore factors associated with BSI in a contemporary cohort of HD patients at a public teaching hospital dialysis center in Israel. METHODS: This was a retrospective cohort study of HD patients with a BSI in the years 2014 to 2018. The primary outcome was the occurrence of BSI. Secondary outcomes were to describe the causative pathogens of BSI, and to assess for risk factors for BSI, and mortality. RESULTS: Included were 251 patients. The mean age was 68.5 ± 13.4 years, 66.9% were male. The mean time from initiation of dialysis was 34.76 ± 40.77 months, interquartile range (IQR) 1-47.5 months and the follow up period of the cohort was 25.17 ± 15.9 months. During the observation period, 44 patients (17.5%) developed 54 BSI events, while 10 of them (3.9% of the whole cohort) developed recurrent BSI events. Gram-negative microorganisms caused 46.3% of all BSI events. 31.4% of these BSI were caused by resistant bacteria. In a multivariate logistic regression analysis, patients receiving dialysis through a central line had a significantly increased risk for BSI adjusted Odds Ratio (aOR) 3.907, p = 0.005, whereas patients' weight was mildly protective (aOR 0.971, p = 0.024). CONCLUSIONS: We noted an increased prevalence of gram-negative pathogens in the etiology of BSI in HD patients. Based on our findings, additional empirical antibiotics addressing gram negative bacteria have been added to our empirical treatment protocol. Our findings highlight the need to follow local epidemiology for implementing appropriate preventative measures and for tailoring appropriate empiric antibiotic therapy.

Association of Nutrition Status at Dialysis Start With Long-Term Survival: A 10-Year Retrospective Study.

OBJECTIVE: The objectives of the study are to explore the association between nutritional status at the initiation of dialysis and the improvement or worsening of nutrition status during first 3 months of dialysis and first 5 years of survival on dialysis. METHODS: Two hundred ninety-seven patients who started dialysis between March 2009 and March 2019 were enrolled in the study. The nutritional status of the patients at dialysis commencement was evaluated by the method of The Integrative Clinical Nutrition Dialysis Score (ICNDS). Improvement or worsening of nutrition status was monitored by calculating the ICNDS slope for each patient enrolled in the study from 3 ICNDS values from the first 3 months on dialysis. The baseline ICNDS and the slope of 3 subsequent monthly ICNDS values were tested for correlation with the odds of all-cause mortality for each of the first 5 years on dialysis. RESULTS: There was a significant difference between the survival odds of patients who started dialysis with an ICNDS at 75 and those who started dialysis with an ICNDS <75 (hazard ratio [HR] 2.505, confidence interval [Cl] 1.235-5.079, P = .011 after 1 year on dialysis;, HR 1.543, Cl 1.083-2.198, P = .016 after 5 years). Deterioration of nutritional status (a negative ICNDS slope) during the first 3 months of dialysis was associated with increased mortality during 1-3 years after dialysis start, compared to a positive ICNDS slope indicating a stable or improved nutritional status (HR 1.732, Cl 1.151-2.607, P = .008 after 3 years on dialysis). CONCLUSIONS: Nutritional status at initiation of dialysis is associated with long-term (5 years) survival. Deterioration of nutritional status during the first 3 months on dialysis significantly increases the risk of death during the first 3 years on dialysis.

The effect of hemodialysis on individual retinal layer thickness.

PURPOSE: The aim of this study was to employ newly developed advanced image analysis software to evaluate changes in retinal layer thickness following hemodialysis. METHODS: A non-randomized prospective study of patients with end-stage renal disease assessed on the same day before and after hemodialysis. Intraocular pressure and central corneal thickness were analyzed, and spectral domain optical coherence tomography results were automatically segmented using the Orion software and then compared. All patients had normal retinal optical coherence tomography findings before hemodialysis. RESULTS: Of the 31 suitable end-stage renal disease patients treated with hemodialysis who provided consent to participate, seven were unable to complete all evaluations, leaving 24 patients for analysis in the final study group. Their mean age was 66.67±14.3 years (range: 35-88), and 62.5% were males. Mean central corneal thickness did not change following hemodialysis (563.4±30.2 µm to 553.1±47.2 µm, p=.247), while mean intraocular pressure decreased (14.48±2.5 mmHg to 13.16±2.28 mmHg, p=.028). Individual mean retinal layer thickness showed no significant change, including the retinal nerve fiber layer (40.9±6.8 µm to 40.1±5.2 µm, p=.412), the ganglion cell and the inner plexiform layer (68.66±8 µm to 69.03±7.6 µm, p=.639), and the photoreceptor layer (50.26±2.8 µm to 50.32±3.1 µm, p=.869). Total retinal thickness similarly remained constant, with a mean of 303.7±17.3 µm before and 304.33±18.4 µm after hemodialysis (p=.571). CONCLUSIONS: Thickness of retinal layers, as assessed by individual segmentation, and central corneal thickness were not affected by hemodialysis treatment, while intraocular pressure was significantly reduced among patients with end-stage renal disease without pre-existing ocular pathology who were undergoing hemodialysis. These results support the view that hemodialysis does not have a negative impact on the retinal morphology of end-stage renal disease patients, who comprise a population with high rates of diabetic and/or hypertensive retinopathy as well as vision-threatening complications.

Serum Obestatin: A Biomarker of Cardiovascular and All-Cause Mortality in Hemodialysis Patients.

BACKGROUND: Recent experimental studies have suggested that obestatin, a proposed anorexigenic gut hormone and a physiological opponent of acyl-ghrelin, has protective cardiovascular effects. We tested the hypothesis that obestatin is independent of inflammatory mediators and/or acyl-ghrelin in predicting outcomes of the maintenance hemodialysis (MHD) population. METHODS: It was a 6-year cohort study on 261 MHD patients. Obestatin, acyl-ghrelin, adipokines (leptin and adiponectin), markers of inflammation and nutrition, prospective all-cause and cardiovascular mortality were studied. RESULTS: During the follow-up, 160 patients died in total, with 74 deaths due to cardiovascular causes. For each ng/mL increase in baseline obestatin level in fully adjusted models (including malnutrition-inflammation score, Interleukin-6 [IL-6], adipokines and acyl-ghrelin), the hazard for death from all causes was 0.90 (95% CI 0.81-0.99) and for cardiovascular death 0.85 (95% CI 0.73-0.99). However, these associations were more robust in the subgroup of patients aged above 71 years: 0.85 (95% CI 0.73-0.98) for all-cause death and 0.66 (95% CI 0.52-0.85) for cardiovascular death. An interaction between high IL-6 (above median) and low obestatin (below median) levels for increased risk of all-cause mortality (synergy index [SI] 5.14, p = 0.001) and cardiovascular mortality (SI 4.81, p = 0.02) emerged in the development of multivariable adjusted models. Interactions were also observed between obestatin, Tumor necrosis factor-alpha, adipokines and acyl-ghrelin, which were associated with mortality risk. CONCLUSION: Serum obestatin behaves as a biomarker for cardiovascular and all-cause mortality in MHD patients. The prognostic ability of obestatin in this regard is independent of inflammation, nutritional status, acyl-ghrelin's and adipokines' activity and is modified by age being very prominent in patients older than 71 years.

Estimating of Residual Kidney Function by Multi-Frequency Bioelectrical Impedance Analysis in Hemodialysis Patients Without Urine Collection.

BACKGROUND/AIMS: Residual kidney function (RKF) is a pivotal predictor of better clinical outcomes in maintenance hemodialysis (MHD) patients. So far there has been no attempt to use bioimpedance analysis (BIA) measurements to calculate residual glomerular filtration rate (GFR) in dialysis population. We hypothesized that performing of multi-frequency BIA at the beginning and end of hemodialysis session can enable us to predict the measured residual GFR in MHD patients. Thus our aim was to develop and validate a new RKF prediction equation using multi-frequency BIA in MHD patients. METHODS: It was diagnostic test evaluation study in a prospective cohort. Participants (n=88; mean age, 66.3±13.2 years, 59.1% males) were recruited from a single hemodialysis center. A new equation (eGFRBIA) to predict RKF, utilizing BIA measurements performed pre- and post-dialysis, was generated and cross-validated by the leave-one-out procedure. GFR estimated as the mean of urea and creatinine clearance (mGFR) using urine collections during entire interdialytic period. RESULTS: A prediction equation for mGFR that includes both pre- and post-dialysis BIA measurements provided a better estimate than either pre- or post-dialysis measurements alone. Mean bias between predicted and measured GFR was -0.12 ml/min. Passing and Bablok regression showed no bias and no significant deviation in linearity. Concordance correlation coefficient indicated good agreement between the eGFRBIA and mGFR (0.75, P<0.001). Using cut-off predicted mGFR levels >2 ml/min/1.73 m2 yielded an area under curve of 0.96, sensitivity 85%, and specificity 89% in predicting mGFR. The κ scores for intraobserver reproducibility were consistent with substantial agreement between first and second estimation of RKF according to eGFRBIA (weighted κ was 0.60 [0.37-0.83]). CONCLUSION: We present a valid and clinically obtainable method to predict RKF in MHD patients. This method, which uses BIA, may prove as accurate, convenient and easily reproducible while it is operator independent.

Age modifies the association between serum obestatin, appetite and nutritional status in maintenance hemodialysis patients.

BACKGROUND/OBJECTIVES: Increased age is strongly associated with anorexia and protein-energy wasting (PEW) in maintenance hemodialysis (MHD) population. We hypothesized that the association of obestatin, a recently discovered anorexigenic gut hormone, with appetite and nutritional status differs by age groups. SUBJECTS/METHODS: We performed a cross-sectional study on 261MHD patients. Obestatin, acyl-ghrelin, markers of inflammation (CRP, IL-6, TNF-α) and nutrition (self-reported appetite, dietary intake, biochemical nutritional parameters, and body composition) were measured. RESULTS: Obestatin was associated with appetite in multivariate analyses even after controlling for such confounders as lean body mass (LBM), IL-6 and acyl-ghrelin in patients younger than 71 years. For each ng/ml increase in obestatin levels, the odds for diminished appetite was 0.75 (95% CI: 0.59-0.96). However, these associations were not observed in patients 71 years and older. Multivariable logistic regression models (including appetite) also showed increasing odds for PEW (defined by ESPEN consensus-based criteria for the diagnosis of malnutrition) across increasing serum obestatin levels (OR: 1.51, 95% CI: 1.05-2.18) in patients 71 years and older. However, after lean body mass (LBM) was added to this model, the association between obestatin and malnutrition was abolished (OR: 1.26, 95% CI: 0.83-1.91). CONCLUSIONS: The association between serum obestatin, appetite and PEW differs depending on age in MHD patients. A positive link with appetite exists in patients younger than 71 years, whereas this relationship disappears by the age of 71. In older MHD patients, obestatin is associated with PEW through mechanisms related to LBM, but not to appetite.

Phosphate binders, appetite and nutritional status in maintenance hemodialysis patients.

BACKGROUND AND OBJECTIVES: The potential side effects of common phosphate binders are gastrointestinal in practice. We hypothesized that regular use of phosphate binders may be associated with decreased appetite, dietary intake and consequently, poor nutritional status. METHODS AND STUDY DESIGN: This was cross-sectional study of 78 patients (mean age 67.5±13.0, 34.6% women) undergoing maintenance hemodialysis (MHD) treatment. Participants were divided into three equal groups - sevelamer (n=25), lanthanum (n=24) and the control group (n=29). Eating motivation was assessed using visual analogue scales (VAS) and by a self-reported appetite assessment which was graded on a 5-point Likert scale. Main outcome measure was differences in VAS scores for appetite, dietary intake and nutritional status (malnutrition-inflammation score [MIS]) in the study groups. RESULTS: Appetite, dietary intake, biochemical nutritional markers, anthropometric measures and MIS were similar in the three groups. A statistically significant difference was observed in sensation of fullness between the groups: multivariable adjusted ORs in the sevelamer carbonate group was 4.90 (95% CI: 1.12 to 21.43), p=0.04 and in the lanthanum carbonate group was 5.18 (95% CI: 1.15 to 23.30), p=0.03 versus the control group. However, no linear association was observed between MIS scores and VAS scores for appetite in any study group. CONCLUSIONS: Regular use of these phosphate binders was not associated with anorexia, decreased dietary intake and nutritional status in the study population. Therefore, there is no preference in the choice of phosphate binders in MHD patients with hyperphosphatemia, even those who are at nutritional risk.