Single Hemodialysis Session Research Articles

An intradialytic increase in serum interleukin-6 levels is associated with an increased mortality in hemodialysis patients.

The inflammatory marker interleukin-6 (IL-6) increases early in the inflammatory cascade. The aim of this study was to evaluate whether an increase in serum IL-6 levels during a hemodialysis (HD) session is associated with mortality. 57 adult patients treated with HD for more than 1 month were prospectively studied over a 3-year follow-up period. Demographic and clinical data were collected and blood samples were drawn before and after a midweek HD session. Events of death and censoring were recorded. During the 3-year follow-up, 50.8% of the patients died. In univariate Cox regression analysis, an increase in IL-6 levels during HD was associated with an increased mortality (HR 1.41 per pg/ml; 95% CI 1.06 to 1.88; P = .017). In multivariate Cox models, the only independent predictors of all-cause mortality were: an increase in IL-6 levels during dialysis (HR 1.46 per pg/ml; 95% CI 1.08 to 1.98; P = .014), higher baseline C-reactive protein (CRP) levels and older age. When predictors of an increase in serum IL-6 levels during HD were introduced into the model, mortality was still significantly associated with IL-6 elevation during dialysis (HR 1.47 per pg/ml, 95% CI 1.01 to 2.14; P = .045). A rise in serum IL-6 levels during a single HD session is associated with a higher mortality among HD patients, independent of predialysis CRP or IL-6 levels. The results may imply the presence of an intradialytic inflammatory response that affects survival in HD patients.

The effects of single hemodialysis session on arterial stiffness in hemodialysis patients.

Increased arterial stiffness in hemodialysis patients is a strong predictor of cardiovascular morbidity and mortality. Pulse wave velocity (PWV) and augmentation index (AIx), which are markers of arterial stiffness, were used to determine the severity of vascular damage noninvasively. This study aimed to investigate the effects of solute volume removal and hemodynamic changes on PWV and AIx of a single hemodialysis session. Thirty hemodialysis patients were enrolled in the study. Before initiation of hemodialysis, every 15 minutes during hemodialysis, and 30 minutes after the completion of the session, measurements of PWV and AIx@75 (normalized with heart rate 75 bpm) were obtained from each patient. Body composition was analyzed by bioimpedance spectroscopy device before and 30 minutes after completion of the hemodialysis session. During the hemodialysis, no significant change was observed in AIx@75. However, PWV decreased steadily during the session reaching statistically significant level at 135th minute (P = 0.026), with a maximal drop at 210th minute (P < 0.001). At 210th minute, decrease in PWV correlated positively with the decrease in central systolic blood pressure, central diastolic blood pressure, central pulse pressure, augmentation pressure, and AIx@75. Multiple regression analysis showed that decrease in PWV at 210th minute was associated with decrease in central systolic blood pressure and central pulse pressure. Ultrafiltration during hemodialysis had no significant effect on PWV and AIx@75. Delta urea correlated positively with delta PWV at 240th minute. A significant decrease in PWV was observed during hemodialysis and correlated with urea reduction; however, we were unable to document any effect of volume removal on arterial stiffness.

Circulating Double-Stranded DNA in Plasma of Hemodialysis Patients and its Association with Iron Stores.

Chronic kidney disease (CKD) is characterized by oxidative stress, and most of the adverse effects of CKD are mediated by iron-catalyzed ROS generation. The DNA, in particular, is more susceptible to attack by ROS than other proteins and membrane lipids. Considering the evidence on the relationship between CKD, iron metabolism, and DNA damage, the purpose of this study was to evaluate cell-free DNA in the plasma of HD patients and its association with iron status biomarkers and kidney function. Measurements of the circulating cell-free DNA in plasma, iron, ferritin, transferrin and other biochemical parameters were performed in 40 chronic hemodialysis (HD) patients and 40 healthy controls. Blood samples were also collected 1 hour before and 1 hour after the HD session to check whether a single HD session would be able to promote an increase in cell-free DNA in the plasma. Cell-free DNA in plasma was significantly increased in HD patients in comparison with healthy controls (p = 0.0017), and significant correlations were observed between cell-free DNA and GFR and ferritin. Our findings showed that a single HD session was not able to promote an increase in cell-free DNA. It was reported that increased ferritin levels and reduced GFR were associated with higher circulating cell-free DNA. The HD patients presented increased ceIl-free DNA. In addition, the increase of ferritin levels and the decrease of GFR were associated with DNA damage. We also observed that a single HD session was not able to promote an increase in cell-free DNA.

Long-term Hemodialysis Corrects Left Ventricular Dyssynchrony in End-stage Renal Disease: A Study with Gated Technetium-99m Sestamibi Myocardial Perfusion Single-photon Emission Computed Tomography.

Left ventricular (LV) dyssynchrony is common in patients with end-stage renal disease (ESRD), and echocardiographic assessment has shown that it can be improved by a single session of hemodialysis (HD). The aim of this study was to assess the effects of chronic HD on LV dyssynchrony in patients ESRD by means of gated technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography (GSPECT) with phase analysis. Twelve patients with ESRD underwent GSPECT and echocardiography before the start of long-term HD (baseline) and 3 months later. In addition, 7 control subjects matched for age and sex underwent GSPECT and echocardiography within a 2-month period. To evaluate LV dyssynchrony, both histogram bandwidth (HBW) and phase standard deviation (PSD) were determined with phase analysis of GSPECT images. The end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction were also measured with GSPECT, and the LV mass index (LVMI) was measured with echocardiography. The LV dyssynchrony, volume, function, and mass were compared among control subjects, patients with ESRD at baseline, and patients with ESRD after 3 months of chronic HD. The LV dyssynchrony, volume, and mass at baseline were significantly greater in patients with ESRD than in control subjects (HBW, 65.5°±54.4° vs. 22.3°±7.5°, P<0.05; PSD, 21.0°±15.5° vs. 7.6°±5.5°, P<0.05; EDV, 105.7±29.2 vs. 72.3±13.9 mL, P<0.05; ESV, 44.3±22.1 vs. 20.9±10.3 mL, P<0.05; LVMI, 136.5±48.3 vs. 65.4±5.6 g/m(2), P<0.01). From baseline to the third month of chronic HD, there were significant increases in EDV (78.6±25.4 vs. 105.7±29.2 mL, P<0.01) and ESV (27.6±16.2 vs. 44.3±22.1 mL, P<0.01) and significant decreases in HBW (65.5°±54.4° vs. 31.0°±15.7°, P<0.01) and PSD (21.0°±15.5° vs. 10.0°±8.2°, P<0.01). Chronic HD decreased LV dyssynchrony and volume in patients with ESRD. Serial phase analysis of GSPECT images is a useful method of assessing the effects of long-term HD on LV dyssynchrony and volume in patients with ESRD.

The serum lipids levels may be underestimated in patients on hemodialysis.

Although lipid disorders are a well-known risk factor for cardiovascular disease (CVD) in the general population, the optimal management with lipid-lowering therapy to reduce CVD risks and mortality in hemodialysis (HD) patients remains controversial. In the clinical setting, dyslipidemia can be diagnosed based on the detection of elevated lipid concentrations at the beginning of HD. This study investigated changes in the levels of serum lipids during a single HD session. The serum total cholesterol, triglyceride and high-density lipoprotein (HDL) cholesterol levels were measured in 31 HD patients at zero, two and four hours after the beginning of a single HD session. The data were analyzed using the Wilcoxon signed-rank test, a linear mixed model and Spearman's rank correlation analysis. The serum total cholesterol, HDL cholesterol and non-HDL cholesterol levels increased significantly during the HD session. Even after the lipid parameters were corrected for changes in the total protein level, the total cholesterol and HDL cholesterol levels increased, whereas the non-HDL cholesterol levels did not change significantly. The percentage change in the serum levels of these lipid fractions correlated strongly with the percentage change in the ultrafiltration volume per body weight. In contrast, the serum triglyceride levels were decreased significantly at two hours compared with the levels noted at the beginning of HD and gradually increased at four hours. The serum lipid levels are influenced significantly by HD treatment and ultrafiltration. Evaluating the degree of dyslipidemia at the beginning of a HD session may therefore underestimate the levels of serum lipids in HD patients with a large amount of weight gain, thus resulting in the use of insufficient lipid-lowering therapy.

Acute effect of hemodialysis on arterial elasticity.

Reduced arterial elasticity is an independent predictor of cardiovascular mortality in patients with end-stage renal disease (ESRD). Hemodialysis (HD) treatment per se can bring additional risk factors for vascular disease. Our study was designed to determine whether a single hemodialysis session leads to an acute alteration in parameters of arterial elasticity in ESRD. In this study, 58 patients undergoing chronic hemodialysis and 29 healthy controls were enrolled. Large artery elasticity index (LAEI) and the small artery elasticity index (SAEI) were measured by applanation tonometry. The acute effect of a hemodialysis session on arterial elasticity indices was assessed by comparison of prehemodialysis and posthemodialysis determinations. At baseline, LAEI did not differ significantly in patients compared with controls. In contrast, the SAEI was significantly lower in patients (4.1 ± 2.6 mL/mmHg x 100) than in healthy individuals (8.9 ± 3.4 mL/mmHg x 100, P < 0.05). In patients with ESRD, no significant changes in LAEI was observed after HD, but SAEI deteriorated significantly (from 4.1 ± 2.6 mL/mmHg x 100 to 3.4 ± 2.3, P < 0.05). We conclude that ESRD patients face a significant reduction in SAEI, which is exacerbated by a dialysis procedure.

Oxidative Stress Markers in Children With End Stage Kidney Disease

Objectives: Our objective was to evaluate oxidative stress markers in children with end-stage kidney disease and to study the influence of hemodialysis on the oxidative stress markers. Background: End-stage kidney disease (ESKD or ESRD) is associated with numerous complications, which may partially result from excessive amounts of reactive oxygen species and/or decreased antioxidant activity. Methods: Twenty pediatric patients with end-stage kidney disease on maintenance hemodialysis were compared with twenty healthy controls. Investigations included were: complete blood count (CBC), urea, creatinine, uric acid, total antioxidant capacity (TAC), malondialdehyde (MDA), hemoglobin level and antioxidant enzymes activities superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). These investigations were conducted in children on hemodialysis (before and after session) and healthy controls. Results: Total antioxidant capacity (TAC) and malondialdehyde (MDA) concentrations were higher in hemodialysis group as compared with healthy controls. Total antioxidant capacity and malondialdehyde were significantly higher pre dialysis as compared with their levels post dialysis. The activity of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) were significantly higher in healthy children as compared with hemodialysis group (before and after dialysis). Conclusion: Increased oxidative stress occurs in children on maintenance dialysis. The activity of the enzymatic antioxidant defense system is highly reduced in plasma of pediatric dialysis patients. Oxidative stress is improved during every single hemodialysis session in children.

Therapeutic C3 inhibitor Cp40 abrogates complement activation induced by modern hemodialysis filters

Approximately 350,000 individuals in the United States rely on maintenance hemodialysis treatment because of end-stage renal disease. Despite improvements in dialysis technology, the mortality rate for patients treated with maintenance dialysis is still exceptionally high, with a 5-year survival rate of only 35%. Many patients succumb to conditions resulting at least in part from the chronic induction of inflammation. Among the triggers of inflammation, the complement system is of particular importance, being a well-appreciated mediator of inflammatory processes that is involved in many pathologic states. Here we used a refined pre-clinical model of hemodialysis in cynomolgus monkeys to confirm that even modern, polymer-based hemodialysis filters activate complement and to evaluate the potential of Cp40, a peptidic C3 inhibitor, to attenuate hemodialysis-induced complement activation. Our data show marked induction of complement activation even after only a single session of hemodialysis. Importantly, complete inhibition of complement activation was achieved in response to two distinct Cp40 treatment regimens. Further, we show that application of Cp40 during hemodialysis resulted in increased levels of the anti-inflammatory cytokine IL-10, indicating that Cp40 may be a potent and cost-effective treatment option for attenuating chronic inflammatory conditions in dialysis-dependent patients.

The Impact of Dialysis Modality on Novel Markers of Stress Reaction, Matrix Remodeling and Endothelial Damage in Children on Chronic Dialysis

Background/Aims: Dialysis triggers stress reaction, matrix remodeling and endothelial damage, but little is known about the changes it induces on selected heat shock proteins (Hsp90α), adhesion molecules (E-cadherin, sE-selectin), metalloproteinases (MMP-8) and their extracellular inducer (EMMPRIN). The aim of this study was to assess serum concentrations of the above-mentioned parameters in children on chronic dialysis. Methods: 19 patients on hemodialysis (HD), 22 children on peritoneal dialysis (PD) and 30 age-matched controls were examined. Serum concentrations of parameters were assessed by ELISA. Results: Hsp90α, MMP-8, EMMPRIN and E-cadherin concentrations were significantly increased in children on dialysis vs. controls and higher levels were in HD than PD patients. There was no difference in the level of sE-selectin between HD and PD modalities. A single HD session diminished Hsp90α, MMP-8, EMMPRIN and E-cadherin values, but had no impact on sE-selectin levels. Conclusions: Hemodialysis evokes stress reaction, matrix and endothelium destruction, to a greater extent than peritoneal dialysis. Single hemodialysis influences circulating cells rather than endothelial cells.

Acute Haemodialysis-induced Changes in Tissue Doppler Echocardiography Parameters.

Tissue Doppler imaging (TDI) is a method that determines the tissue motion and velocity within the myocardium. To characterize acute haemodialysis (HD)-induced changes in TDI-derived indices for patients that have end-stage renal disease (ESRD). Cross sectional study. Conventional echocardiography and TDI methods were applied to study ESRD patients (n=58) before and after HD. Pulmonary venous flow, mitral inflow, and TDI signals of the lateral and septal mitral annulus were examined for the determination of altered left-ventricular diastolic filling parameters. Flow velocities from early- (E) and late-atrial (A) peak transmitral; peak pulmonary vein systolic (S) and diastolic (D); and myocardial peak systolic (Sm) and peak early (Em) and late (Am) diastolic mitral annular velocities were also assessed for changes. Transmitral E and A velocities and the E/A ratio decreased significantly after HD (p<0.001). Pulmonary vein S (p<0.001) and D (p<0.001) velocities decreased, and S/D ratios increased significantly (p=0.027). HD led to a reduction in septal Em (p<0.001), lateral Em (p=0.006), and Am (p<0.001) velocities. Contrary to the decreases in Em and Am, the Em/Am ratio remained unchanged. A single HD session was associated with an acute deterioration in the diastolic parameters. Since the Em/Am ratio remained unchanged, we conclude that this index is a relatively load-independent measure of diastolic function in HD patients.

Effects of hemodialysis on ventricular activation time in children with end‐stage renal disease

Patients with end-stage renal disease are affected by cardiovascular complications, including disturbances of the heart intraventricular conduction. Body surface potential mapping is a non-invasive electrocardiographic detection method of initial disturbances in heart activation propagation. A goal of the study was to analyze the effects of single hemodialysis (HD) session on ventricular activation time (VAT) maps obtained from hemodialyzed children. The study group consisted of 13 hemodialyzed children (age: 6-18 years). The control group is composed of 26 healthy subjects. In each HD patient, 12-lead electrocardiogram and echocardiography examinations were performed. Isochrone heart maps, reflecting body surface distribution of VAT isolines, were recorded from an 87-electrode HPM-7100 system for body surface potential mapping, before (group B) and after HD session (group A). The distribution of isochrones and VAT values, as recorded in the HD patients, differed significantly from the reference VAT map for controls. The highest VAT maximal value was noted in group B (Me: 110 vs. 62 ms in the control group; P < 0.001), becoming significantly lower after HD session (Me: 98 ms for group A vs. 110 ms for group B; P < 0.001). Ventricular activation time maps, recorded before HD session, showed significant VAT delays with isochrone arrangement specific for the left bundle branch block. After HD session, VAT maps presented significant changes, suggesting a normalization process. Ventricular activation time maps in children with end-stage renal disease exhibited disturbances of intraventricular conduction within the left bundle branch block, undetectable on standard electrocardiogram. A single HD session resulted in VAT map improvement related to overall HD treatment duration.

Study on corrected QT interval before and after haemodialysis among patients on beta blocker therapy

Introduction : In recent days patients with end stage renal disease on maintenance hemodialysis is emerging.In the conventional ECG the prolonged QT interval has been associated with arrhythmogenesis in a number of cardiac disorders.It has been documented that dialysis patients exhibit sustained activation of the sympathetic nervous system and that the diseased kidney themselves are the trigger of this overactivity 106,107 .The sympathetic over activity is associated with mortality and worse cardiovascular outcomes. 19 So the study to assess the effect of beta blockers in chronic renal failure patients using QT interval is taken up. Materials & methods : A cross sectional hospital based study was done on fifty adult patients on hemodialysis for more than three months at associate hospitals of Kasturba Medical College, Mangalore.Informed consent was taken from them.Twelve-lead electrocardiographs were performed at 10mm/mv and 25mm/s using software based digital ECG recorder (Schiller Healthcare India Pvt Ltd.)10 minutes before and 10 min after a single hemodialysis session. The automatic QT interval was obtained. Statistical analysis was done using Students t-test and chi-square test. P value of ?0.05 was considered significant. Discussion : This study demonstrates that QT interval increases significantly after hemodialysis.There was no significant differences in QT dispersion in end stage renal disease patients on beta blockers and those patients not on beta blockers in our study.However, long term clinical trials are desperately needed to evaluate the safety and efficacy of beta blockers in chronic dialysis patients.

Correlations and time course of FGF23 and markers of bone metabolism in maintenance hemodialysis patients

ObjectiveParathyroid hormone (iPTH) and fibroblast growth factor 23 (FGF23) are elevated in secondary hyperparathyroidism. In hemodialysis, higher dialysate calcium (1.5mmol/L) induces intradialytic suppression of iPTH, whereas its impact on FGF23 and markers of bone metabolism is unknown. We assessed the time course of FGF23 and markers of bone metabolism in relationship to dialysate calcium. Design and methodsIn this prospective cohort study of 19 patients on maintenance hemodialysis, we measured serum calcium (sCa), inorganic phosphate (iP), blood urea nitrogen (BUN), β2-microglobulin (ßMG), iPTH, FGF23, aminoterminal propeptide type 1 procollagen (P1NP), C-telopeptide of type I collagen for bone degradation (CTX-I), osteocalcin (OC), bone specific alkaline phosphatase (BALP), and tartrate-resistant acid phosphatase (TRAP5b) during a single hemodialysis session at baseline, 1, 2, and 3h of dialysis. The time course of measured parameters was compared according to groups of prescribed dialysate calcium of 1.25mmol/L and 1.5mmol/L. ResultsiPTH declined in the 1.5mmol/L dialysis group as serum calcium increased whereas it tended to increase in the 1.25mmol/L group without significant changes in serum calcium. Patients on long-term dialysate calcium of 1.5mmol/L had significantly lower CTX-I levels and tended to lower levels of iPTH, FGF23, OC, P1NP and TRAP5b at the start of dialysis compared to those on 1.25mmol/L. CTX-I, FGF23 and OC but not BALP, P1NP and TRAP5b decreased during dialysis independent of dialysate calcium. ConclusionsIn spite of immediate effects on iPTH, dialysate calcium does not acutely affect other parameters of bone and mineral metabolism. Short summaryDialysate calcium concentration is known to have both immediate and longer-term impact on parathyroid hormone levels in hemodialysis patients. Little is known about the acute impact of dialysate calcium on bone metabolism. In this cross-sectional study of prevalent hemodialysis patients, we found no evidence of immediate short-term dialysate calcium-induced changes of fibroblast growth factor 23 or anabolic and catabolic markers of bone turnover during hemodialysis. However, differences in CTX-I and to a lesser extent other parameters between groups of higher and lower dialysate calcium suggest a longer-term effect that remains to be validated.

Influence of polysulphone-derived dialysis membranes on the interaction of circulating mononuclear cells with the endothelium.

Cardiovascular morbidity in hemodialysis (HD) patients may be influenced by the activation of circulating mononuclear cells (MCs) with subsequently increased endothelium interaction. The use of more biocompatible membranes would reduce this monocyte activation. We compare monocyte activation after using two different high-flux polymers, polysulphone and polyethersulphone. The first part of the study was done with 10 patients who successively received dialysis for 2 weeks with polysulphone and polyethersulphone. The second part with 30 patients dialyzed for 3 months with polysulphone or polyethersulphone. Blood samples were taken before (pre-HD) and after (post-HD) the first HD session with each membrane to evaluate the effect of a single HD session. To assess acute and chronic effects of membranes, blood samples were taken pre-HD, after 2 weeks (first part of study) and after 3 months (second part of study). MCs were isolated from blood and then incubated with cultured human endothelial cells to evaluate MC adhesion, MC-dependent endothelial toxicity, and endothelial protein expressions of nitric oxide synthase and endothelin-converting enzyme-1 (ECE-1). One single HD session did not induce any changes. Dialysis for 2 weeks (first part of study) with polyethersulphone reduced MC adhesion to endothelium, cellular toxicity, and ECE-1 protein expression compared to polysulphone or basal conditions. Dialysis for 3 months (second part of study) increased MC adhesion to endothelium, whereas cellular toxicity was decreased with both dialyzers compared to the basal situation. Although polyethersulphone HD decreased the interaction of MC with the endothelium in short-term experiments, both membranes were comparable in the long-term.

The effect of hemodialysis on cardiac enzyme levels and echocardiographic parameters.

Cardiac troponins are specific and sensitive markers of myocardial damage. Troponin levels may increase without an obvious active cardiac disease in hemodialysis patients. In this study, we aimed to investigate the effect of a single hemodialysis session on echocardiographic parameters and cardiac enzyme levels, including cTn-I, creatine phosphokinase (CPK), and creatine kinase-MB (CK-MB). Forty patients under chronic hemodialysis treatment enrolled in this prospective study. All the patients had a physical examination and underwent echocardiography before and after hemodialysis. cTn-I, CPK and CK-MB levels were also determined before and after hemodialysis in all patients. Post-dialysis cTn-I levels were significantly higher compared to pre-dialysis levels (p = 0.03). cTn-I levels increased in 26 patients, did not change in 1 patient and decreased in 13 patients after hemodialysis when compared to the values determined before hemodialysis. There was no significant increase in CPK and CK-MB levels after dialysis. Statistically significant changes were detected in the end-systolic diameter of the left ventricle, end-diastolic diameter of left ventricle, ejection fraction, diameter of the left atrium, diameter of the right atrium, pulmonary artery pressure and end-diastolic diameter of the right ventricle. However, there was no significant relation between these echocardiographic changes and ultrafiltration volume, blood flow rate, age, and gender. Hemodialysis leads to an increase in cTnI levels. However, the effect of increased cTnI levels on survival rates in hemodialysis patients with underlying coronary artery disease has not yet been determined. Prospective multi-center studies with large sample size are required to clarify this issue.

Hemodialysis restored iron distribution that was sequestered in the spleen by bilateral nephrectomy.

Acute kidney injury (AKI) is associated with dysregulated iron metabolism, which may play a significant role in cellular injury. The effect of hemodialysis (HD) on iron metabolism in AKI therapy has not been well defined. The effects of HD on iron parameters were tested in control rats and bilateral nephrectomy (BNx) rats. The BNx rats were divided into the following three groups: 1) the sham-operated group (BNx-Sham), 2) the BNx group, and 3) the HD group (BNx-HD), which received HD therapy 40-45 h after BNx. Sections of the liver or spleen were stained with Berlin blue to examine the accumulation of iron. The mRNA levels of hepcidin and ferroportin 1 in the spleen and liver were also quantified using RT-PCR. In the BNx group, the plasma iron and hematocrit levels were decreased, and hepcidin levels were increased. The iron staining in the spleen in the BNx group was significantly more intense than that in the BNx-Sham group; however, after an HD session, splenic iron staining diminished to the level of the sham group along with an increase in plasma iron and a decrease in hepcidin. BNx moved iron from hemoglobin and the plasma to the spleen, which is associated with an increase in plasma hepcidin. A single HD session accelerated the release of iron from the spleen, and the increased plasma iron was linked to the removal of hepcidin. Our data suggested that hepcidin might dynamically modulate the iron metabolism in BNx as well as in HD.

Long-term and short-term effects of hemodialysis on liver function evaluated using the galactose single-point test.

Aim. The galactose single-point (GSP) test assesses functioning liver mass by measuring the galactose concentration in the blood 1 hour after its administration. The purpose of this study was to investigate the impact of hemodialysis (HD) on short-term and long-term liver function by use of GSP test. Methods. Seventy-four patients on maintenance HD (46 males and 28 females, 60.38 ± 11.86 years) with a mean time on HD of 60.77 ± 48.31 months were studied. The GSP values were compared in two groups: (1) before and after single session HD, and (2) after one year of maintenance HD. Results. Among the 74 HD patient, only the post-HD Cr levels and years on dialysis were significantly correlated with GSP values (r = 0.280, P < 0.05 and r = −0.240, P < 0.05, resp.). 14 of 74 patients were selected for GSP evaluation before and after a single HD session, and the hepatic clearance of galactose was similar (pre-HD 410 ± 254 g/mL, post-HD 439 ± 298 g/mL, P = 0.49). GSP values decreased from 420.20 ± 175.26 g/mL to 383.40 ± 153.97 g/mL after 1 year maintenance HD in other 15 patients (mean difference: 19.00 ± 37.66 g/mL, P < 0.05). Conclusions. Patients on maintenance HD for several years may experience improvement of their liver function. However, a single HD session does not affect liver function significantly as assessed by the GSP test. Since the metabolism of galactose is dependent on liver blood flow and hepatic functional mass, further studies are needed.

Acute hemodialysis effects on doppler echocardiographic indices.

Conventional echocardiographic (ECHO) parameters of systolic and diastolic function of the left ventricular (LV) have been shown to be load dependent. However, the impact of pre-load reduction on tissue Doppler (TD) parameters of LV function is incompletely understood. To evaluate the effect of a single hemodialysis (HD) session on LV systolic and diastolic function using pulsed Doppler echocardiography and pulsed tissue Doppler imaging (TDI), we studied 81 chronic HD patients (40 males; mean age 52.4 ± 16.4 years) with these tools. ECHO parameters were obtained 30 min before and 30 min after HD. Fluid volume removed by HD was 1640 ± 730 cm³. HD led to reduction in LV end-diastolic volume (P <0.001), end-systolic volume (P <0.001), left atrium area (P <0.001), peak early (E-wave) trans-mitral flow velocity (P <0.001), the ratio of early to late Doppler velocities of diastolic mitral inflow (P <0.001) and aortic time velocity integral (P <0.001). No significant change in peak S velocity of pulmonary vein flow after HD was noted. Early and late diastolic (E') TDI velocities and the ratio of early to late TDI diastolic velocities (E'/A') on the lateral side of the mitral annulus decreased significantly after HD (P = 0.013; P = 0.007 and P = 0.008, respectively). Velocity of flow progression (Vp) during diastole was not affected by pre-load reduction. Pulmonary artery systolic pressure and the diameter of the inferior vena cava decreased significantly (P <0.001 and P <0.001, respectively) after HD. We conclude that most of the Doppler-derived indices of diastolic function are pre-load-dependent and velocity of flow progression was minimally affected by pre-load reduction in HD patients.

Skin and Plasma Autofluorescence During Hemodialysis: A Pilot Study

Skin autofluorescence (AF) is related to the accumulation of advanced glycation end products (AGEs) and is one of the strongest prognostic markers of mortality in hemodialysis (HD) patients. The aim of this pilot study was to investigate whether changes in skin AF appear after a single HD session and if they might be related to changes in plasma AF. Skin and plasma AF were measured before and after HD in 35 patients on maintenance HD therapy (nine women and 26 men, median age 68 years, range 33-83). Median dialysis time was 4 h (range 3-5.5). Skin AF was measured noninvasively with an AGE Reader, and plasma AF was measured before and after HD at 460 nm after excitation at 370 nm. The HD patients had on average a 65% higher skin AF value than age-matched healthy persons (P < 0.001). Plasma AF was reduced by 14% (P < 0.001), whereas skin AF was not changed after a single HD treatment. No significant influence of the reduced plasma AF on skin AF levels was found. This suggests that the measurement of skin AF can be performed during the whole dialysis period and is not directly influenced by the changes in plasma AF during HD.

Duplex Ultrasound Volumetric Flow Analysis before and after Hemodialysis in Patients with Brachio-cephalic Fistulae

The United Kingdom Renal Association recommends duplex ultrasound to monitor arteriovenous fistula (AVF) flow rates during surveillance. Significant flow rate changes should prompt further investigation or treatment to avoid a failing fistula. Hemodialysis is known to alter the hemorrheologic and physiologic factors with a potential impact on measured flow rates. The aim of this study was to determine the difference in flow rate measured with duplex ultrasound before and after a single hemodialysis session in patients with brachial-cephalic fistulae. Patients with brachial-cephalic AVFs in our dialysis populations who were undergoing regular hemodialysis without recent intervention (less than six weeks) were invited to participate. Flow measurements were made pre-and post-hemodialysis using a Zonare ultrasound machine. The vascular scientist was always blinded to the pre-hemodialysis flow. A total of 157 patients were identified with brachial-cephalic fistulae. Following exclusions, 119 patients were eligible. However, a further 58 were excluded because they declined or did not attend leaving 61 patients in the study. Paired t test showed a statistically significant reduction in flow rate of 105 mL/min (P=0.026) post-hemodialysis which equates to a -6.9% change in flow (95% C.I. -12.7 to -0.8%). Bland-Altman analysis showed limits of flow rate agreement between -599 mL/min and +810 mL/min (+/-1.96 s.d.). Whilst we have shown a statistically significant change in flow rate post-hemodialysis, this is small and should be taken in the context of previously accepted interobserver variability. Therefore, the practical and financial considerations of implementing an AVF surveillance programme are likely to outweigh the minimal benefit of consistency that would be enabled by strict protocol of pre-hemodialysis flow measurements.