Single Hemodialysis Research Articles

The influence of a single hemodialysis procedure on human T lymphocytes

At the moment it is unknown to what extent the impaired function of T lymphocytes in ESRD patients depends on uremia, and to what extent on hemodialysis (HD) procedure. Therefore, the purpose of the study was to evaluate percentages of T lymphocyte subpopulations ex vivo, plasma concentrations of IL12p70, TNF, IL-10, IL-6, IL-1β, IL-8 cytokines and selected proliferation parameters of in vitro activated T lymphocytes in HD patients before and after single HD procedure using flow cytometry. We demonstrated that the percentage of CD8+ cells ex vivo was decreased while the CD4+/CD8+ ratio was increased after HD procedure. Also, there was significant decrease in the percentage of CD8+HLA-DR+, CD8+CD69+ and CD8+CD95+ cells after HD. At the same time, an increase in the percentage of CD4+CD95+ cells was observed after HD. From all analyzed cytokines, only the concentration of IL-8 was significantly decreased after HD procedure. A single HD session enhanced proliferation capacity of CD4+ cells but not CD8+ cells in vitro by increasing number of cell divisions and percentage of dividing cells. Our results show that a single hemodialysis can have immunomodulatory effect on HD patients and may contribute to the state of immune deficiency observed in patients with ESRD.

Diastolic dysfunction in asymptomatic hemodialysis patients in the light of the current echocardiographic guidelines.

The prevalence of the left ventricular hypertrophy (LVH) is very high in end-stage renal disease treated by hemodialysis. Diastolic dysfunction is a frequent consequence and leads to the development of heart failure with preserved ejection fraction. New American/European echocardiographic guidelines for the assessment of diastolic function simplified the evaluation and were published recently. The aim of this study was to reveal if the new guidelines stratify asymptomatic hemodialysis patients by the levels of brain-natriuretic peptide (BNP). A cohort of 46 patients hemodialyzed in one center with the lack of overt heart failure, systolic dysfunction, arrhythmia or significant valvular disease were examined by echocardiography before and after a single hemodialysis and blood samples for BNP analysis were drawn at both occasions. The LVH was present in 53% of patients, concentric remodeling in another 17%. Higher indexed left ventricular mass was related to higher BNP levels (r = 0.58, p = 0.0001). Before hemodialysis, diastolic dysfunction was present in 61%: grade 1 in 25%, grade 2 in 21% and grade 3 in 8%. The higher grade of diastolic dysfunction was associated with the incremental increase of BNP. The post-dialysis echocardiography did not allow the assessment of diastolic function in as many as 37% of patients. Our study has shown that the application of the current guidelines for the assessment of diastolic function based on simple four criteria differentiate hemodialysis symptomless patients with preserved systolic function according to BNP levels. BNP levels also rose together with the left ventricular mass. The ratio E/e' medial seemed to be a better predictor of increased BNP than E/e' lateral or E/e' averaged.

The Effect of Mechanically-Generated Vibrations on the Efficacy of Hemodialysis; Assessment of Patients' Safety: Preliminary Reports.

Muscle activity during a hemodialysis procedure improves its efficacy. We have formulated a hypothesis that vibrations generated by a specially-designed dialysis chair can, the same as physical exercise, affect the filtering of various fluids between fluid spaces during the hemodialysis procedure. This prospective and interventional study included 21 dialyzed patients. During a single dialysis session, each patient used a prototype device with the working name “vibrating chair”. The chair’s drive used a low-power cage induction motor, which, along with the worm gear motor, was a part of the low-frequency (3.14 Hz) vibration-generating assembly with an amplitude of 4 mm. Tests and measurements were performed before and after the vibration dialysis. After a single hemodialysis session including five 3-min cycles of vibrations, an increase in in relation to non-vibration ( vs. ) was seen. Urea reduction ratio increased significantly ( vs. ). A significant increase in systolic blood pressure was observed between the first and the third measurement ( vs. ). The use of a chair generating low-frequency vibrations increased dialysis adequacy; furthermore, it seems an acceptable and safe alternative to intradialytic exercise.

Low dialysate sodium levels for chronic haemodialysis.

Cardiovascular (CV) disease is the leading cause of death in dialysis patients, and strongly associated with fluid overload and hypertension. It is plausible that low dialysate [Na+] may decrease total body sodium content, thereby reducing fluid overload and hypertension, and ultimately reducing CV morbidity and mortality. This review evaluated harms and benefits of using a low (< 138 mM) dialysate [Na+] for maintenance haemodialysis (HD) patients. We searched the Cochrane Kidney and Transplant Register of Studies up to 7 August 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. Randomised controlled trials (RCTs), both parallel and cross-over, of low (< 138 mM) versus neutral (138 to 140 mM) or high (> 140 mM) dialysate [Na+] for maintenance HD patients were included. Two investigators independently screened studies for inclusion and extracted data. Statistical analyses were performed using random effects models, and results expressed as risk ratios (RR) for dichotomous outcomes, and mean differences (MD) or standardised MD (SMD) for continuous outcomes, with 95% confidence intervals (CI). Confidence in the evidence was assessed using GRADE. We included 12 studies randomising 310 patients, with data available for 266 patients after dropout. All but one study evaluated a fixed concentration of low dialysate [Na+], and one profiled dialysate [Na+]. Three studies were parallel group, and the remaining nine cross-over. Of the latter, only two used a washout between intervention and control periods. Most studies were short-term with a median (interquartile range) follow-up of 3 (3, 8.5) weeks. Two were of a single HD session, and two of a single week's HD. Half of the studies were conducted prior to 2000, and five reported use of obsolete HD practices. Risks of bias in the included studies were often high or unclear, lowering confidence in the results.Compared to neutral or high dialysate [Na+], low dialysate [Na+] had the following effects on "efficacy" endpoints: reduced interdialytic weight gain (10 studies: MD -0.35 kg, 95% CI -0.18 to -0.51; high certainty evidence); probably reduced predialysis mean arterial blood pressure (BP) (4 studies: MD -3.58 mmHg, 95% CI -5.46 to -1.69; moderate certainty evidence); probably reduced postdialysis mean arterial BP (MAP) (4 studies: MD -3.26 mmHg, 95% CI -1.70 to -4.82; moderate certainty evidence); probably reduced predialysis serum [Na+] (7 studies: MD -1.69 mM, 95% CI -2.36 to -1.02; moderate certainty evidence); may have reduced antihypertensive medication (2 studies: SMD -0.67 SD, 95% CI -1.07 to -0.28; low certainty evidence). Compared to neutral or high dialysate [Na+], low dialysate [Na+] had the following effects on "safety" endpoints: probably increased intradialytic hypotension events (9 studies: RR 1.56, 95% 1.17 to 2.07; moderate certainty evidence); probably increased intradialytic cramps (6 studies: RR 1.77, 95% 1.15 to 2.73; moderate certainty evidence).Compared to neutral or high dialysate [Na+], low dialysate [Na+] may make little or no difference to: intradialytic BP (2 studies: MD for systolic BP -3.99 mmHg, 95% CI -17.96 to 9.99; diastolic BP 1.33 mmHg, 95% CI -6.29 to 8.95; low certainty evidence); interdialytic BP (2 studies:, MD for systolic BP 0.17 mmHg, 95% CI -5.42 to 5.08; diastolic BP -2.00 mmHg, 95% CI -4.84 to 0.84; low certainty evidence); dietary salt intake (2 studies: MD -0.21g/d, 95% CI -0.48 to 0.06; low certainty evidence).Due to very low quality of evidence, it is uncertain whether low dialysate [Na+] changed extracellular fluid status, venous tone, arterial vascular resistance, left ventricular mass or volumes, thirst or fatigue. Studies did not examine cardiovascular or all-cause mortality, cardiovascular events, or hospitalisation. It is likely that low dialysate [Na+] reduces intradialytic weight gain and BP, which are effects directionally associated with improved outcomes. However, the intervention probably also increases intradialytic hypotension and reduces serum [Na+], effects that are associated with increased mortality risk. The effect of the intervention on overall patient health and well-being is unknown. Further evidence is needed in the form of longer-term studies in contemporary settings, evaluating end-organ effects in small-scale mechanistic studies using optimal methods, and clinical outcomes in large-scale multicentre RCTs.

Evaluation of the effect of hemodialysis on left ventricular longitudinal strain function of myocardium in patients with uremia by velocity vector imaging

Objective To investigate the velocity vector imaging (VVI) technique to evaluate hemodialysis on left ventricular function and application value of longitudinal strain effect of three myocardial layers. Method Echocardiography was performed in 35 cases of uremia patients with high flux hemodialysis, respectively before and after dialysis within 2H. Use VVI software to analyze the two-dimensional images after conventional measurement and image acquisition and obtain 17 segments of left ventricular peak systolic longitudinal strain (LPS) and layered whole layer strain. Results Left atrial diameter (LAD), left ventricular end diastolic and end systolic diameter (LVIDd, LVIDs), and left ventricular diastolic end and end systolic volume (EDV, ESV), stroke volume (SV)were reduced after dialysis(P 0.05).Layered strain parameter: Compared with before dialysis, the peak systolic longitudinal strain (LPS) of left ventricular global layer and inner layer,the global layer, subendocardial layer, middle layer and epicardial layer of the basal segment,the global layer and subendocardial layer of middle segment were lower than before dialysis. The difference was statistically significant (P 0.05).Single hemodialysis has a negative effect on left ventricular function. Therefore, it is necessary to monitor the heart function in hemodialysis patients to avoid the occurrence of cardiovascular events during dialysis and after dialysis. Conclusion VVI can be more accurate to evaluate the effect of blood dialysis in uremic patients with left ventricular myocardial regional and global function, and has potential applications in clinical practice.

An Exploratory Study of Person-Centered Care in a Large Urban Hemodialysis Program in Canada Using a Qualitative Case-Study Methodology.

Background:Person-centered care (PCC) can benefit patients, clinical staff, and health care organizations, but has not yet been widely adopted into practice. Hemodialysis is a unique care environment in which clinical staff can be involved with patients for protracted periods of time each week and often over a number of years. While kidney care is arguably more holistic than other chronic condition management programs, most patients requiring hemodialysis do not receive care that is optimally person-centered.Objective:The purpose of this research was to explore how care is experienced and provided in a large urban hemodialysis program in western Canada in relation to key principles of PCC. In addition, we wanted to understand what factors at an individual, unit, and organizational level facilitate or inhibit PCC in this environment.Methods:We used a qualitative case-study approach to explore multiple perspectives of care provision using a number of data sources including semi-structured interviews with patients, family members, clinical staff, and administrative staff, as well as observing patterns of clinical practice in local hemodialysis units.Findings:In our study of a single hemodialysis program, we found limited evidence of PCC. Overall, patients reported that their care was good and they had positive relationships with their care team. However, they did not feel involved in decisions regarding their care or consider it to be individualized. In general, providers acknowledged the potential benefits of PCC but were constrained in their practice by a number of factors, including individual perceptions of their role, a prescriptive care environment, and an organizational focus on managing demand.Conclusions:Evidence of PCC within hemodialysis services was limited, with a number of individual, unit level, and organizational barriers mitigating against its adoption and spread.

New markers of cell migration and inflammation in children with chronic kidney disease

Context: Chronic kidney disease (CKD) is characterized by immunocompetent cell migration and inflammation. Monocyte chemoattractant protein (MCP)-1 and macrophage colony-stimulating factor (MCSF) stimulate monocyte migration and transition into macrophages with subsequent release of neopterin. Objective: The aim of the study was to analyze these parameters in children with various stages of CKD. Material and methods: The study group consisted of 41 CKD children, 19 patients on haemodialysis (HD), 22 children on automated peritoneal dialysis (APD) and 23 controls. Serum concentrations of MCP-1, MCSF and neopterin were assessed by ELISA. Correlations to matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) were analyzed. Results: MCP-1, MCSF and neopterin were significantly elevated in all patients versus controls and the highest values concerned HD children. A single HD session lessened the concentrations of all parameters, yet they rose back before the next HD session. All markers correlated with MMPs and TIMPs in different combinations. Conclusions: Systemic inflammation and cell migration are triggered by CKD and additionally aggravated by chronic dialysis, with the more evident negative impact of HD than APD. Discrepancies in MCP1, MCSF and neopterin serum concentrations suggest they may serve as new markers of cellular and inflammatory responses in children with CKD.

Hepatitis C virus transmission in a Dutch haemodialysis unit: detailed outbreak investigation using NS5A gene sequencing

Haemodialysis is a risk factor for hepatitis C virus (HCV) transmission. Two patients receiving haemodialysis in a Dutch dialysis unit in The Hague were found to seroconvertto HCV in December 2016 after the yearly routine control for blood-borne viruses. Following the presumed time of infection, three chronically infected HCV patients were identified as possible index cases. To confirm inter-patient transmission and to identify the source. Molecular investigation and review of medical records were performed. Both of the incident cases and one of the three possible index cases were demonstrated to be infected with HCV genotype 2b based on 5'UTR sequencing. Epidemiological relatedness between these viruses was further investigated by sequencing of the NS5A region. Phylogenetic analysis clearly identified the incident cases and the index case to represent a cluster distinct from unrelated controls with HCV genotype 2b. Detailed review of the medical records identified two possible incidents that might have resulted in the HCV transmission cases: contamination of the venous pressure-sensing port due to high venous pressures or incomplete compliance with infection control precautions of the unit staff during handling of two incidents, that occurred at the same time in a single haemodialysis session with the index patient as well as both incident cases present. This study demonstrates that detailed incident recording in combination with state-of-the-art molecular investigations such as sequencing of the NS5A region resulted in unravelling a set of two HCV transmissions that occurred at a haemodialysis unit.

Short- and long-term effects of hemodialysis on platelet and monocyte activity markers of atherosclerosis in patients with end-stage renal disease.

In hemodialysis (HD) patients cardiovascular events represent the predominant cause of mortality. Since platelet and monocyte activity markers play an important role in cardiovascular mortality, this study assessed the influence of HD on these markers. Forty one HD patients (25 male, 16 female) were included. Blood samples were obtained before and after a single HD session at baseline and again after an elapsed period of 114 ± 21 days (91-175 days) on maintenance hemodialysis. Surface expression of CD40L and CD62P on platelets, tissue factor binding on monocytes and platelet-monocyte aggregates were measured by flow cytometry. Plasma levels of monocyte chemotactic protein-1 (MCP-1), interleukin-6 (IL-6), tumor necrosis factor alpha (TNFa) and soluble CD40L were analyzed by enzyme linked immunosorbent assay. Tissue factor on monocytes was significantly increased after a single HD session at baseline (p = 0.041), whereas platelet-monocyte aggregates, the expression of CD40L and CD62P on platelets did not change significantly. After a mean of 114 ± 21 days of HD therapy, tissue factor on monocytes (p < 0.0001), platelet-monocytes aggregates (p < 0.0001), plasma levels of MCP-1 (p = 0.012) and TNFa (p = 0.046) were significantly decreased compared to baseline values. In contrast, platelet surface expression of CD40L and CD62P as well as plasma levels of sCD40L and IL-6 were not attenuated significantly. There was no significant correlation detected between the markers examined and the cumulative time on hemodialysis. Platelet and monocyte activity markers assessed in this study do not appear to be significantly increased by HD therapy. Therefore, these markers probably cannot be accountable for increased cardiovascular mortality in chronic HD patients.

Changes in the inflammatory and oxidative stress markers during a single hemodialysis session in patients with chronic kidney disease

Background: Cardiovascular disease (CVD) is a common cause of morbidity and mortality in end-stage renal disease (ESRD) patients on hemodialysis (HD) among whom it is 5–20 times higher than in the general population. Some of the nontraditional risk factors such as oxidative stress and inflammation are related to the progress of CVD in HD patients. Several, but not all studies, reported that inflammatory and oxidative stress markers are increased during a single session of HD, mimicking changes that occur during acute immune activation. This study was taken up to evaluate the changes in the inflammatory and oxidative stress markers during a single HD session in patients with chronic kidney disease.Methods: Twenty-five ESRD patients on maintenance HD and 25 controls were included in the study. Blood samples were obtained from the patients before starting of hemodialysis (pre-HD) and after completion of hemodialysis (post-HD). The changes in serum Pentraxin-3, hs-CRP, malondialdehyde (MDA) and ferric reducing ability of plasma (FRAP) levels were measured in pre- and post-HD ESRD patients and compared with healthy control group.Results: This study found increased levels of Pentraxin-3, hs-CRP, MDA, and decreased level of FRAP in HD patients compared to controls.Conclusions: Hemodialysis procedure contributes to inflammation and oxidative stress.

Evaluation of a single hemodialysis on right ventricular function in patients by 3-dimensional speckle tracking imaging

Objective To evaluate the change of right ventricular function before and after single hemodialysis by 3-dimensional speckle tracking imaging(3D-STI). Methods Seventy-six patients with end-stage renal disease(ESRD) and 35 controls were included.ESRD patients were divided into normal left ventricular ejection fraction group(LVEF≥50%, 46 cases, group A)and decreased LVEF group(LVEF<50%, 30 cases, group B). Conventional echocardiography and 3D-STI parameters including right ventricular end diastolic volume(RVEDV), right ventricular end systolic volume (RVESV), right ventricular ejection fraction(RVEF), right ventricular septal longitudinal strain[RVLS(Septum)], right ventricular free wall longitudinal strain [RVLS(Freewall )], basal segment of right ventricular diameter[RVDd(base )], right ventricular middle diameter [RVDd(mid )], right ventricular long diameter (RVLD) and the upper and lower right ventricular fractional area change (FAC) were performed in patients and controls before and after a single hemodialysis. Results ①RVEDV, RVESV, RVDd(base), RVDd(mid), RVLD before a single hemodialysis in group A and B were significantly higher than those in control group (all P<0.05). RVEF, RVLS Freewall, RVLS(Septum) and FAC in group A and B were significantly lower than those in control group (all P<0.05). ②RVEDV, RVESV, RVEF, RVLD, RVLS(Freewall) were significantly lower in group A after a single hemodialysis(all P<0.05); RVEDV, RVESV, RVEF, RVLS(Freewall), RVLS(Septum) were significantly lower in group B after a single hemodialysis(all P<0.05); RVEDV, RVESV, RVEF, RVLS(Septum) and RVLS(Freewall) in group B before a single hemodialysis were lower than those in group A (all P<0.05). The difference of RVLS Septum decrease in group B after a single hemodialysis was higher than that in group A(P<0.05); The linear correlations analysis showed that the difference of body weight before and after a single hemodialysis was negatively related with the difference of RVLS(Freewall) before and after a single hemodialysis(group A: r=0.351, P=0.017; group B: r=0.696, P=0.000). Conclusions A single hemodialysis may have injurious effects on right ventricular systolic function and reduce strain value, which is more significant in group B(LVEF<50%). Cardiac dysfunction of patients may be remitted by reasonable control of water intake. Key words: Echocardiography; End-stage renal disease; Hemodialysis; Ventricular function, right; Three-dimensional speckle tracking imaging

Left ventricular twist before and after haemodialysis: an analysis using speckle-tracking echocardiography.

SummaryBackgroundThe most commonly used parameter of cardiac function in the chronic kidney disease (CKD) patient is ejection fraction (EF), using transthoracic echocardiography (TTE). EF is a highly load-dependent measurement, which varies considerably in CKD patients undergoing haemodialysis. The aim of this pilot study was to evaluate a novel measure of myocardial function, left ventricular twist, which is defined as the ‘wringing action of the heart’, using speckletracking echocardiography in CKD patients before and after haemodialysis.MethodsTwenty-six patients were recruited from the Chris Hani Baragwanath Hospital haemodialysis unit. TTE was performed according to a detailed standardised protocol before and after a single haemodialysis session. Echocardiography was also performed on 26 age- and gendermatched healthy subjects.ResultsThe mean age of the control versus CKD group was 44 ± 11.4 and 43.4 ± 12.2 years, respectively; 46% were male. Apical rotation was diminished in CKD patients compared to controls (4.83 ± 2.3 vs 6.31 ± 1.6 °; p = 0.01) despite no difference in EF (61.7 ± 6.2 vs 58.8 ± 13; p = 0.68). There were no differences in the components of twist: apical rotation, basal rotation and net twist before and after dialysis, despite an increase in EF (58.8 ± 13.7 vs 61.2 ± 13.6; p = 0.02) following dialysis.ConclusionUnlike EF, the components of twist are relatively independent of changes in haemodynamic load seen during dialysis. The decrease in apical rotation may represent an early marker of cardiac pathology in the late-stage CKD patient.

Biological variation of procalcitonin levels in hemodialysis patients.

There is no obvious evidence regarding biological variation of procalcitonin (PCT) levels in hemodialysis (HD) patients without infections. The aim of this study was to determine the within- and between-person biological variation of PCT levels in HD patients without infections. A multicenter, prospective, cohort study enrolled 123 HD patients without any signs of infectious disease. Baseline PCT levels were determined pre- and post-HD, and then repeated pre-HD PCT measurements were performed at 2, 4, 8, 12, 16, 20, and 24 weeks after baseline blood-sampling, regardless of the presence or absence of infectious disease. Analytical variation (CVa), the within-person biological variation (CVi), between-person biological variation (CVb), individual index (II), and the reference change value (RCV) were calculated. The mean age was 62.4 years, 76.4% were male, and 32.5% had diabetes. The mean duration of HD was 87months. The median value for baseline pre-HD PCT was 0.23ng/mL, which is much higher than the reference level for healthy individuals. PCT levels decreased of 46.6% after a single HD session. CVi was 24.9%, CVb was 54.2%, II was 0.46, and RCV was calculated as 96.4% with 99% probability. The PCT level was significantly higher in stable HD patients without manifest bacterial infection. CVb was more variable than CVi in HD patients, which indicates that relative change is more important than absolute PCT levels for diagnosing bacterial infection, and doubling or more of the baseline PCT level may imply the presence of a bacterial infection in HD patients.

Ocular changes during hemodialysis in patients with end-stage renal disease

BackgroundTo explore ocular changes during hemodialysis (HD) in chronic renal failure patients and to determine the effects of different causes of renal failure during HD.MethodsA total of 90 eyes from 45 end-stage renal disease (ESRD) patients undergoing HD were evaluated in this study. All ophthalmological examinations were conducted within 1 h before and after a single HD session. The HD patients were divided into primary kidney disease (KD), hypertensive KD, diabetic KD (DM-KD) and unknown etiology subgroups according to the primary etiology of renal failure. The statistics of 38 eyes from 19 healthy people were set as normal control.ResultsTear break-up time (TBUT) (P = 0.020), Schirmer’s I test results (P = 0.030), anterior chamber depth (ACD) (P = 0.006), lens thickness (LT) (P < 0.001) and choroidal thickness (CHT) (P < 0.001)decreased significantly after a single HD. The retinal nerve fiber layer (RNFL) thickness and average retinal thickness (RT) increased after HD, especially in the nasal inner macula (NIM) subfield (P < 0.001), the inferior inner macula (IIM) subfield (P = 0.004) and the superior outer macula (SOM) subfield (P = 0.012). TBUT, Schirmer’s I test, IOP, RT, and CHT were correlated with one or more parameters. All ESRD patients regardless of etiology had the same trend for most parameters during HD, with the exception of the logMAR of BCVA, central corneal thickness, RNFL thickness and CHT.ConclusionsHD may affect a range of ocular parameters in ESRD patients. Dry eye parameters, RT and CHT exhibited the most obvious changes. Different etiologies tended to have similar trends in ocular parameter changes during HD.

Pilot Study of the Effects of High-Protein Meals During Hemodialysis on Intradialytic Hypotension in Patients Undergoing Maintenance Hemodialysis

Patients undergoing hemodialysis (HD) have high protein and energy requirements, and protein-energy wasting is common and associated with poor outcomes. Eating during dialysis may improve nutritional status by counteracting the catabolic effects of HD treatment; but eating during HD may be discouraged because of concerns of postprandial hypotension. However, little data are available to support this practice. In this study, we hypothesized that high-protein meals during HD do not lead to symptomatic intradialytic hypotension events. A 9-week, nonrandomized, parallel-arm study. A single in-center HD clinic. Eighteen patients undergoing HD from 2 shifts completed the study. Patients were aged 62±16 years with dialysis vintage of 3.4±2.6years. Patients in the intervention group (n=9) undergoing HD received meals of ∼30 g protein and ∼1/3 daily recommended intakes of sodium, potassium, phosphorus, and fluid during dialysis for 25 consecutive HD sessions. The control group (n=9) completed all aspects of the study including a visit by study personnel but were not given meals. The 25 consecutive sessions before the start of the intervention/control phase were used as a baseline comparison for each patient. Symptomatic hypotension event frequency. In the intervention arm, there were 19 symptomatic hypotension events in 5 patients prestudy and 18 events in 6 patients during the study. In the control arm, there were 16 events in 7 patients prestudy and 13 events in 7 patients during the study. Change in the frequency of symptomatic hypotension events from prestudy to during study was not different between groups (P=.71). There was no effect of meals on nutritional status, but patients reported positive attitudes toward receiving meals during dialysis. High-protein meals during HD did not increase symptomatic hypotension events. Larger, longer term studies are needed to confirm these results and evaluate whether high-protein meals on dialysis benefit nutritional status and clinical outcomes.

Association between hippuric acid and left ventricular hypertrophy in maintenance hemodialysis patients

BackgroundLeft ventricular hypertrophy (LVH) is one of the most common cardiac abnormalities in patients with end-stage renal disease. Hippuric acid (HA), a harmful uremic toxin, is known to be elevated in patients with uremia, and serum HA levels are associated with neurological symptoms, metabolic acidosis, and accelerated renal damage associated with chronic kidney disease. However, the pathophysiological role of HA in patients with uremia remains unclear. We investigated the association between serum HA levels and echocardiographic measurements in patients undergoing hemodialysis (HD) treatment. MethodsEighty consecutive patients treated at a single HD center (44 males, 36 females; mean age 66 y, mean HD duration 6 y) were included in this study. Comprehensive echocardiography was performed after HD. Blood samples were obtained before HD. ResultsPearson's correlation analysis revealed that serum HA levels were positively correlated with diastolic blood pressure, serum creatinine, left ventricular mass index, end diastolic interventricular septal thickness, left ventricular end-diastolic diameter, left ventricular end systolic diameter, end systolic left ventricular posterior wall thickness, and left atrium diameter, and negatively correlated with age. Furthermore, the HD patients with LVH had higher median serum HA levels than those without LVH (34.2 vs. 18.1 μg/ml, p = 0.003). Multiple logistic regression analysis revealed that HA was independently associated with LVH even after adjusting for known biomarkers. Moreover, the receiver operator characteristics curve of HA showed that a HA level of >26.9 μg/ml was associated with LVH. ConclusionsHA was significantly associated with LVH. HA could be a novel biomarker of left ventricular overload, which is closely associated with an increased risk of death in HD patients.

Volume status and arterial blood pressures are associated with arterial stiffness in hemodialysis patients.

Arterial stiffness is a strong predictor of mortality in hemodialysis patients. In this study, we aimed to investigate possible relations of arterial stiffness with volume status determined by bioimpedance analysis and aortic blood pressure parameters. Also, effects of a single hemodialysis session on these parameters were studied. A total of 75 hemodialysis patients (M/F: 43/32; mean age: 53 ± 17) were enrolled. Carotid-femoral pulse wave velocity, augmentation index, and aortic pulse pressure were measured by applanation tonometry before and after hemodialysis. Extracellular fluid and total body fluid volumes were determined by bioimpedance analysis. Carotid-femoral pulse wave velocity (9.30 ± 3.30 vs 7.59 ± 2.66 m/s, p < 0.001), augmentation index (24.52 ± 9.42 vs 20.28 ± 10.19, p < 0.001), and aortic pulse pressure (38 ± 14 vs 29 ± 8 mmHg, p < 0.001) significantly decreased after hemodialysis. Pre-dialysis carotid-femoral pulse wave velocity was associated with age (r2 = 0.15, p = 0.01), total cholesterol (r2 = 0.06, p = 0.02), peripheral mean blood pressure (r2 = 0.10, p = 0.005), aortic-mean blood pressure (r2 = 0.06, p = 0.02), aortic pulse pressure (r2 = 0.14, p = 0.001), and extracellular fluid/total body fluid (r2 = 0.30, p < 0.0001). Pre-dialysis augmentation index was associated with total cholesterol (r2 = 0.06, p = 0,02), aortic-mean blood pressure (r2 = 0.16, p < 0.001), and aortic pulse pressure (r2 = 0.22, p < 0.001). Δcarotid-femoral pulse wave velocity was associated with Δaortic-mean blood pressure (r2 = 0.06, p = 0.02) and inversely correlated with baseline carotid-femoral pulse wave velocity (r2 = 0.29, p < 0.001). Pre-dialysis Δaugmentation index was significantly associated with Δaortic-mean blood pressure (r2 = 0.09, p = 0.009) and Δaortic pulse pressure (r2 = 0.06, p = 0.03) and inversely associated with baseline augmentation index (r2 = 0.14, p = 0.001). In multiple linear regression analysis (adjusted R2 = 0.46, p < 0.001) to determine the factors predicting Log carotid-femoral pulse wave velocity, extracellular fluid/total body fluid and peripheral mean blood pressure significantly predicted Log carotid-femoral pulse wave velocity (p = 0.001 and p = 0.006, respectively). Carotid-femoral pulse wave velocity, augmentation index, and aortic pulse pressure significantly decreased after hemodialysis. Arterial stiffness was associated with both peripheral and aortic blood pressure. Furthermore, reduction in arterial stiffness parameters was related to reduction in aortic blood pressure. Pre-dialysis carotid-femoral pulse wave velocity was associated with volume status determined by bioimpedance analysis. Volume control may improve not only the aortic blood pressure measurements but also arterial stiffness in hemodialysis patients.

Systemic haemodynamics in haemodialysis: intradialytic changes and prognostic significance

BackgroundAlthough haemodialysis (HD) leads to alterations of systemic haemodynamics that can be monitored using dilution methods, there is a lack of data on the diagnostic and prognostic significance of haemodynamic monitoring during routine HD.MethodsIn this multicentre study, we measured cardiac index (CI), access flow (AF) and central blood volume index (CBVI) during a single HD session in stable HD patients (n = 215) using the Transonic HD03 monitor (Transonic, Ithaca, NY, USA). Systemic CI (SCI) was defined as CI corrected for AF. In a subset of patients (n = 82), total end-diastolic volume index (TEDVI) and total ejection fraction (TEF) were derived from dilution curves. Data were correlated with clinical parameters, cardiac biomarkers and bioimpedance measurements (body composition monitor; Fresenius Medical Care, Homburg, Germany). Mortality was assessed prospectively after a median follow-up of 2.6 years.ResultsMedian CI, CBVI and AF were 2.8 L/min/m2 (interquartile range 2.4–3.4), 15 mL/kg (14.5–15.7) and 980 mL/min (740–1415), respectively, at the beginning of HD. At the end of HD, CI, CBVI and AF significantly fell by −10% (−22 to 3, P < 0.0001), −9% (−23 to 3, P < 0.0001) and −4% (−13 to 5, P = 0.0004), respectively. Peripheral resistance (PR) increased slightly (P = 0.01) and blood pressure fell by −6/−3 mmHg to 128/63 mmHg (P < 0.0001). Independent predictors of ΔCI were age and ultrafiltration rate, whereas AF, overhydration and PR were protective. TEF was strongly associated with mortality [area under the dilution curve 0.77, P < 0.0001], followed by TEDVI (0.72, P = 0.0002) and SCI (0.60, P = 0.02).ConclusionsHD leads to a reduction of CI due to ultrafiltration. Haemodynamic monitoring identifies a significant number of HD patients with cardiac impairment that are at risk for increased mortality.

YKL-40 in patients with end-stage renal disease receiving haemodialysis

Purpose: This study aimed to determine serum YKL-40 in patients with end-stage renal disease (ESRD) on haemodialysis (HD) and to evaluate the prognostic value of serum YKL-40.Methods: Patients >18 years on maintenance HD were included. Serum YKL-40 was measured using ELISA before and after a single HD treatment.Results: A total of 306 patients were included. Median serum YKL-40 concentration was 238 µgL−1 (IQR: 193–291 µgL−1) before HD treatment and 198 µgL−1 (IQR: 147–258 µgL−1) after HD treatment, which corresponded to age-corrected 93th percentile in healthy subjects. All-cause mortality after 2.8 years was 35.9%. Patients with serum YKL-40 in the highest quartile compared with the lowest quartile had a univariate HR of 4.0 (95% CI: 2.2–7.3, p < 0.001) for all-cause mortality which decreased to 2.4 (95% CI: 1.1–4.5, p = 0.01) in multivariate analysis. Time-dependent receiver operating characteristic curves showed that serum YKL-40 after HD treatment had significant higher area under the curves from 90 d (p = 0.004) and throughout the rest of the follow-up period when compared to serum YKL-40 before HD treatment.Conclusion: YKL-40 was highly elevated in patients with ESRD on HD, and dialysis reduced serum YKL-40 concentrations approximately one-sixth. YKL-40 measured after dialysis was independently associated with mortality in HD patients.

Hemodialysis Induces an Acute Decline in Cerebral Blood Flow in Elderly Patients.

The initiation of hemodialysis is associated with an accelerated decline of cognitive function and an increased incidence of cerebrovascular accidents and white matter lesions. Investigators have hypothesized that the repetitive circulatory stress of hemodialysis induces ischemic cerebral injury, but the mechanism is unclear. We studied the acute effect of conventional hemodialysis on cerebral blood flow (CBF), measured by [15O]H2O positron emission tomography-computed tomography (PET-CT). During a single hemodialysis session, three [15O]H2O PET-CT scans were performed: before, early after the start of, and at the end of hemodialysis. We used linear mixed models to study global and regional CBF change during hemodialysis. Twelve patients aged ≥65 years (five women, seven men), with a median dialysis vintage of 46 months, completed the study. Mean (±SD) arterial BP declined from 101±11 mm Hg before hemodialysis to 93±17 mm Hg at the end of hemodialysis. From before the start to the end of hemodialysis, global CBF declined significantly by 10%±15%, from a mean of 34.5 to 30.5 ml/100g per minute (difference, -4.1 ml/100 g per minute; 95% confidence interval, -7.3 to -0.9 ml/100 g per minute; P=0.03). CBF decline (20%) was symptomatic in one patient. Regional CBF declined in all volumes of interest, including the frontal, parietal, temporal, and occipital lobes; cerebellum; and thalamus. Higher tympanic temperature, ultrafiltration volume, ultrafiltration rate, and pH significantly associated with lower CBF. Thus, conventional hemodialysis induces a significant reduction in global and regional CBF in elderly patients. Repetitive intradialytic decreases in CBF may be one mechanism by which hemodialysis induces cerebral ischemic injury.