DNA Methylation: Hemodialysis Versus Hemodiafiltration

Aberrant DNA methylation is an emerging characteristic of chronic kidney disease including dialysis patients. It appears to be associated to inflammation. We compared the global DNA methylation status in 10 control subjects compared to 80 dialysis patients (N = 40 on‐line hemodiafiltration, N = 40 high‐flux hemodialysis) in relation to the dialysis technique and inflammation. Whole blood DNA methylation was assessed with a 5‐mc DNA enzyme linked immunosorbent assay Kit. Global DNA methylation was higher in hemodialysis (HD) compared to on‐line hemodiafiltration (HDF) patients (0.045 vs. 0.039; P < 0.0001) and controls (0.045 vs. 0.0284; P = 0.0002 for HD; 0.039 vs. 0.0284; P = 0.0254 for on‐line HDF). To study the influence of the dialysis technique on DNA methylation we divided dialysis patients according to the median value of 5‐mC. DNA methylation was highest in inflamed patients on hemodialysis. The dialysis technique was the only independent predictor of global DNA methylation in dialysis patients. On‐line HDF could be associated with a favorable DNA methylation profile.     

Dialysis Method Alters the Expression of MicroRNA‐33a and Its Target Genes ABCA1, ABCG1 in THP‐1 Macrophages

Atherosclerosis and accompanying cardiovascular disease are the first causes of mortality in patients undergoing maintenance hemodialysis. Anti‐atherosclerotic effects of hemodiafiltration (HDF) have been reported. Our study aimed to investigate the effect of serum derived from a healthy group (n = 23), before and after hemodialysis (HD) therapy (n = 23), and before and after HDF therapy (n = 17) on the expression of microRNA‐33a and its target genes adenosine triphosphate‐binding cassette transporter A1,G1 (ABCA1, ABCG1) in THP‐1 macrophages. Meanwhile, blood lipids and high‐sensitivity C‐reactive protein (hs‐CRP) were measured in these groups. Our data showed that the expression of miRNA‐33a was lower (P < 0.05) and ABCA1 and ABCG1 were higher (P < 0.05) in the healthy group than pre‐HD and pre‐HDF. miR‐33a was significantly decreased (P < 0.05) but ABCA1, ABCG1 was significantly increased (P < 0.05) in post‐HDF compared with pre‐HDF, while these parameters in pre‐ and post‐ HD groups did not show any significant change (P > 0.05). High density lipoprotein cholesterol (HDL‐C) was higher and hs‐CRP was lower in the healthy group than pre‐HD and pre‐HDF groups. Moreover, a significant increase of HDL‐C (P < 0.05) and decrease (P < 0.05) of hs‐CRP was shown in post‐HDF compared with pre‐HDF, but HD appeared to have no significant change in these subjects. HDF therapy can downregulate miR‐33a expression, and then result in ABCA1, ABCG1 upregulation and an increase in circulating HDL‐C, leading to a possible anti‐atherosclerosis effect to some extent.     

A Randomized Controlled Study on the Effects of Acetate‐Free Biofiltration on Organic Anions and Acid‐Base Balance in Hemodialysis Patients

Metabolic acidosis correction is achieved by the transfer of bicarbonate and other buffer anions in dialysis. The aim of this study was to evaluate changes in the main anions of intermediary metabolism on standard hemodiafiltration (HDF) and on acetate‐free biofiltration (AFB). A prospective, in‐center, crossover study was carried out with 22 patients on maintenance dialysis. Patients were randomly assigned to start with 12 successive sessions of standard HDF with bicarbonate (34 mmol/L) and acetate dialysate (3 mmol/L) or 12 successive sessions of AFB without base in the dialysate. Acetate increased significantly during the standard HDF session from 0.078 ± 0.062 mmol/L to 0.156 ± 0.128 mmol/L (P < 0.05) and remained unchanged at 0.044 ± 0.034 mmol and 0.055 ± 0.028 mmol/L in AFB modality. Differences in the acetate levels were observed at two hours (P < 0.005), at the end (P < 0.005) and thirty minutes after the session between HDF and AFB (P < 0.05). There were significantly more patients above the normal range in HDF group than AFB group (68.1% vs 4.5% P < 0.005) postdialysis and 30 minutes later. Serum lactate and pyruvate concentrations decreased during the sessions without differences between modalities. Citrate decreased only in the AFB group (P < 0.05). Acetoacetate and betahydroxybutyrate increased in both modalities, but the highest betahydroxybutyrate values were detected in HDF (P < 0.05). The sum of postdialysis unusual measured organic anions (OA) were higher in HDF compared to AFB (P < 0.05). AFB achieves an optimal control of acid–base equilibrium through a bicarbonate substitution fluid. It also prevents hyperacetatemia and restores internal homeostasis with less production of intermediary metabolites.     

Cardiovascular Protective Effects of On‐Line Hemodiafiltration: Comparison With Conventional Hemodialysis

Atherosclerotic complications have a significant effect on mortality in patients undergoing hemodialysis (HD) therapy. However, anti‐atherosclerotic and cardioprotective effects of on‐line hemodiafiltration (HDF) remain to be elucidated. We prospectively compared the anti‐atherosclerotic and cardioprotective effects in two randomly divided groups, i.e. on‐line HDF group (n = 13) and conventional HD group (n = 9) for 1 year. Surrogate markers were brachial‐ankle pulse wave velocity (baPWV), intima‐media thickness (IMT) of carotid artery as an atherosclerosis marker, and cardiac functional surrogate markers included left ventricular mass index (LVMI), ejection fraction (EF), and LV diastolic capacity represented as E/A and deceleration time (DT). LVMI in on‐line HDF patients showed significant regression after 1 year of treatment (131.9 ± 25.8 to 116.5 ± 24.7 g/m², P = 0.03), while LVMI in HD patients did not show any significant change (148.0 ± 47.1 to 142.3 ± 35.5 g/m²). Levels of baPWV in HD patients showed a significant increase (11.4%) from basal levels, while on‐line HDF groups showed no significant increase. Furthermore, HD patients showed significant worsening of LV diastolic capacity (E/A: from 0.87 ± 0.12 to 0.79 ± 0.08, P = 0.03), while it was not shown in on‐line HDF patients. Ejection fraction and IMT did not show any significant change in both groups. Serum albumin, C‐reactive protein, β2 microglobulin, blood pressure, and anti‐hypertensive drug use did not change in both groups. On‐line HDF showed a significant improvement in LVMI and prevented a significant worsening of baPWV or LV diastolic capacity compared with patients on conventional HD therapy.     

Effects of Different Blood Purification Methods on Serum Cytokine Levels and Prognosis in Patients With Acute Severe Organophosphorus Pesticide Poisoning

The aim of the present study was to investigate the impact of three different blood purification methods, hemoperfusion (HP), continuous blood purification (CBP), and on‐line high‐volume hemodiafiltration (OL‐HDF), on the survival rate of patients with acute severe organophosphorus pesticide poisoning (ASOPP), as well as on major pro‐inflammatory (interleukin [IL]‐1, IL‐6, tumor necrosis factor‐α [TNF‐α]) and anti‐inflammatory (IL‐10) cytokines in the serum. Eighty‐one ASOPP patients were randomly divided into three groups: HP (N = 23), HP + CBP (N = 26), HP + OL‐HD (N = 32). Serum IL‐1, IL‐6, TNF‐α, and IL‐10 levels were assessed by ELISA before treatment and at 24 and 48 h post‐treatment and survival rates were determined. Patient survival rate was significantly higher in OL‐HDF and CBP treated patients compared with HP group (P < 0.05). A significantly greater clearance effect in serum IL‐1, IL‐6, and TNF‐α levels at 24 and 48 h post‐treatment was observed in CBP and OL‐HDF groups compared with the HP group (P < 0.05). The levels of serum anti‐inflammatory cytokine IL‐10 increased significantly in CBP and OL‐HDF groups compared with the HP group (P < 0.05 at 48 h post‐treatment). In addition, OL‐HDF treatment achieved similar changes in serum TNF‐α, IL‐1, IL‐6 and IL‐10 levels as CBP (P > 0.05). Compared with the HP method, CBP or OL‐HDF combined with HP can rapidly clear inflammatory cytokines, reduce systemic inflammatory response syndrome, and improve the survival of ASOPP patients. Compared with CBP, OL‐HDF is an economical and effective method to treat ASOPP with less technical difficulty and more suitability for rural areas and primary hospitals.     

Red cell metabolism in renal failure—the effect of dialysis

Summary The mechanism of the increased haemoglobin (Hb) and erythrocyte survival in continuous ambulatory peritoneal dialysis (CAPD) compared to haemodialysis (HD) was investigated by measuring hexose monophosphate shunt (HMP) activity and reduced glutathione concentration (GSH) in 12 patients—six patients who were stable on CAPD, and six patients who were stable on HD, and also six normal controls. We confirmed the rise in haemoglobin in the CAPD group. The HMP activity, measured by the liberation of ¹⁴CO₂ from radioactive glucose labelled at the C¹ position shows that both HD and CAPD groups fall into the normal range (normal 3–11%) although the HMP activity is higher in the HD group. The reduced glutathione concentration in the three groups was: normal controls 2.41 ± 0.19 mmol/l; HD 3.31 ± 0.43 mmol/l; CAPD 2.68 ± 0.24 mmol/l. The HD group is significantly higher (P <0.01) than both normal and CAPD. We conclude that the rise in haemoglobin in CAPD patients is not related to a more effective HMP. This suggests other mechanisms i.e. marrow function or red-cell loss in HD may be the reason for the lower haemoglobin in this group.     

Daily dialysis reduces pulse wave velocity in chronic hemodialysis patients

Pulse wave velocity (PWV) is a predictor of morbidity and mortality in patients with end-stage renal disease (ESRD). Dialysis patients show cyclic changes in PWV related to their hydration status and blood pressure. Our aim is to assess the impact of daily dialysis on PWV. We performed a randomized crossover study of 60 patients who underwent standard hemodialysis (HD) three times per week for at least 6 months. Patients were classified into three groups according to their PWV values before (pre-) and after (post-) HD, with a cutoff value of 12 m s(-1), as follows: the low-low (LL) group had normal pre-HD and post-HD PWV; the high-low (HL) group had high pre-HD PWV and normal post-HD PWV; and the high-high (HH) group had high pre- and post-HD PWV. All patients continued standard HD for 2 weeks. A total of 10 patients from each group were randomly assigned to continue standard HD for 1 week and then underwent daily dialysis for 1 week. The remaining 10 patients underwent daily dialysis for 1 week and then underwent standard HD for 1 week. PWV values were measured before and 1 h after each dialysis session. With daily dialysis treatment, 2 of 20 patients (10%) moved from the PWV-HH group to the PWV-HL group, whereas 18 of 20 patients (90%) moved from the PWV-HL group to the PWV-LL group (P = 0.030). Daily dialysis reduces PWV in the ESRD patients. As PWV is a strong predictor of mortality in ESRD and has cyclic variations in patients who are on standard HD, we believe that daily dialysis may be used in patients with high PWV levels to reduce their mortality risk.     

Online Hemodiafiltration Reduces Bisphenol A Levels

Several uremic toxins have been identified and related to higher rates of morbidity and mortality in dialysis patients. Bisphenol A (BPA) accumulates in patients with chronic kidney disease. The aim of this study is to demonstrate the usefulness of online hemodiafiltration (OL‐HDF) in reducing BPA levels. Thirty stable hemodialysis patients were selected to participate in this paired study. During three periods of 3 weeks each, patients were switched from high‐flux hemodialysis (HF‐HD) to OL‐HDF, and back to HF‐HD. BPA levels were measured in the last session of each period (pre‐ and post‐dialysis) using ELISA and HPLC. Twenty‐two patients (mean age 73 ± 14 years; 86.4% males) were included. Measurements of BPA levels by HPLC and ELISA assays showed a weak but significant correlation (r = 0.218, P = 0.012). BPA levels decreased in the OL‐HDF period of hemodialysis, in contrast to the HF‐HD period when they remained stable (P = 0.002). In conclusion, OL‐HDF reduced BPA levels in dialysis patients.     

The redox state of albumin and serious cardiovascular incidence in hemodialysis patients

Human serum albumin is composed of human mercaptoalbumin (HMA) with cysteine residues having reducing powers and oxidized human non-mercaptoalbumin. The aim of this study is to clarify whether such redox state of albumin (HSA-redox) influences the incidence of cardiovascular disease (CVD) in chronic kidney disease patients on regular hemodialysis (HD). We measured HSA-redox using high-performance liquid chromatography in 86 anuric HD patients. The association between HSA-redox and incidental CVD events was evaluated. Twenty patients experienced symptomatic CVD events (16 patients died) at the 2-year follow-up. The fraction of HMA (f(HMA)) showed a significantly lower value in patients with CVD than that without CVD, in both pre-HD (36.5 ± 5.8% and 44.6 ± 9.8%, respectively) and post-HD (57.2 ± 6.2% and 67.2 ± 7.4%, respectively). The adjusted odds ratio (OR) for the incidental CVD event in patients with pre-HD f(HMA) < 40% was 5.0 (95% CI; 1.2 to 21.3), and that in patients with post-HD f(HMA) < 60% was 20.6 (3.2 to 134.7). Likewise, the adjusted OR for the CVD death in patients with pre-HD f(HMA) < 40% was 2.5 (0.6 to 12.5), and that in patients with post-HD f(HMA) < 60% was 25.6 (2.5 to 262.8). In conclusion, HSA-redox is closely related to serious CVD incidence and mortality among HD patients.     

Acute Intradialytic Cardiac Function and Inflammatory Cytokine Changes During High‐Efficiency Online Hemodiafiltration With Acetate‐Free and Standard Dialysis Solutions

Acetate in standard acetate‐containing bicarbonate (AC) dialysis fluid could induce peripheral vasodilatation, suppression of myocardial function, and inflammatory cytokine production, resulting in intradialytic hypotension in conventional hemodialysis (HD) patients. Online hemodiafiltration (HDF) provides superior hemodynamic stability over HD. The potentially additive hemodynamic benefits of the novel acetate‐free bicarbonate (AF) dialysis fluid in online HDF have never been explored before. The present randomized, double‐blind, crossover study was conducted in 22 online HDF patients to investigate the impact of AF dialysis fluid on hemodynamic and cytokine changes compared with AC dialysis fluid in online HDF. The results demonstrated the comparable changes of arterial pressure between AF and AC online HDF. During the study periods, the incidences of composite intradialytic hypotension and other adverse events were not different. The baseline and hourly changes of cardiac index, cardiac output, and peripheral vascular resistance during dialysis were comparable (P = 0.534, 0.199, and 0.641, respectively). The percent reductions of NT‐proBNP and cTnT were not significantly different (72.6 ± 12.3 vs. 72.6 ± 12.8%, P = 0.99 and 35.2 ± 12.8 vs. 36.7 ± 12.0%, P = 0.51). The changes of all pro‐inflammatory cytokines (IL‐2β, IL‐6, IL‐8, and TNF‐α) and anti‐inflammatory cytokine (IL‐10) during dialysis were comparable between both groups. In conclusion, AF dialysis solution does not offer additional hemodynamic benefit for stable online HDF patients. The hemodynamic stability provided by online HDF might protect the adverse effects of acetate.     

Reticulated platelets in uremic patients: Effect of hemodialysis and continuous ambulatory peritoneal dialysis

Platelet RNA content can be detected by flow cytometry using thiazole orange staining to identify platelets recently released into the circulation. We studied platelet RNA content and platelet function in uremic patients under different treatment regimens. Four groups were studied: (I) 15 end-stage renal disease (ESRD) patients (10M/5F) on maintenance hemodialysis (HD); (II) 11 ESRD patients (6M/5F) on continuous ambulatory peritoneal dialysis (CAPD); (III) 8 patients with chronic renal failure managed conservatively (5M/3F); and (IV) 34 controls (20M/14F). A double color labeling technique using a phycoerythrin-tagged antibody against glycoprotein lb (CD42b) and RNA labeling by thiazole orange was performed and read by flow cytometry. Aggregation studies were made in platelet-rich plasma using ADP, epinephrine, collagen, arachidonic acid, and ristocetin. In group I, samples were also obtained after HD. Platelet counts did not differ among the groups. Aggregation studies showed a lower response to ADP and ristocetin in the HD patients, but not in the CAPD or in the chronic renal failure patients. The percentage of platelets with high RNA content in group I was significantly lower than in controls (3.72 ± 1.72% vs. 9.05 ± 3.53%, P < 0.01), but was also lower than in the remaining groups (I vs. II P < 0.01, and I vs. III P < 0.01). No differences were seen in platelet RNA content among groups II (8.67 ± 2.73%), III (9.14 ± 3.04%) and IV. In group I, the percentage of reticulated platelets decreased further after HD (2.14 ± 1.09%, P < 0.01). Aggregation studies showed a significantly lower response to ADP and ristocetin in group I (P < 0.05), but not in groups II or III in comparison with controls. Aggregation response to ADP and ristocetin decreased after HD (P < 0.05). In conclusion, HD may decrease the percentage of RNA-rich platelets through elimination of the younger and more active platelets and worsen the thrombopathy present in uremic patients.     

Randomized Pilot Trial Between Prostaglandin I2 Analog and Anti‐Platelet Drugs on Peripheral Arterial Disease in Hemodialysis Patients

The effect of the prostaglandin I₂ analog, beraprost sodium (BPS), on hemodialysis (HD) patients with peripheral arterial disease (PAD) has not been fully elucidated. The effect of BPS was compared to that of PAD drugs in HD patients with PAD in a multicenter randomized prospective interventional pilot study (J‐PADD). Seventy‐two PAD patients on HD were entered and randomly divided into two groups; that is, BPS group (Group A: n = 35) and PAD drug (cilostazol or sarpogrelate) group (Group B: n = 37). Primary endpoint was changes in skin perfusion pressure (SPP). Kidney Disease Quality of Life (KDQOL) score, cardiovascular events, PAD events, and adverse events were also evaluated. SPP increased significantly in both groups at 24 weeks from their basal levels. The absolute increase of SPP in Group A and Group B were 15.4 ± 30.0 mm Hg (P < 0.0001) and 20.2 ± 22.1 mm Hg (P = 0.025) (instep), and 13.8 ± 19.3 mm Hg (P < 0.0001) and 9.2 ± 16.3 mm Hg (P = 0.041) (sole), respectively. Changes of KDQOL score showed significantly better result in the role of physical score in Group A compared with Group B. Although heart rate was unchanged in Group A, 9.3/min increase was seen in Group B patients who received cilostazol. There was no intergroup difference in cardiovascular events and/or PAD events between the two groups during the study period. This exploratory pilot study suggested BPS was as effective as anti‐platelet drugs in improving microcirculation in HD patients.     

Difficulty in Improving Malnutrition and Low‐grade Inflammation in Diabetic Patients on Peritoneal Dialysis

Continuous ambulatory peritoneal dialysis (CAPD) is commonly used for renal replacement therapy in diabetes mellitus (DM) patients. We investigated the changes of peritoneal transport characteristics, nutritional status, and adequacy and inflammation parameters in diabetic CAPD patients (N = 17) compared to non‐diabetic patients (N = 23). Peritoneal equilibrium testing, nutritional, biochemical, and anthropometric parameters and adequacy were prospectively assessed at 1 (baseline), 6 and 12 months after initiating CAPD. The levels of several nutritional parameters were lower and did not change in DM patients over time (P < 0.05) and significantly improved in the non‐DM patients over time (P < 0.05). Total weekly creatinine clearance and residual renal function exhibited a rapid decline (P < 0.05) and inflammation parameter levels were higher in DM patients (P < 0.05). Our results showed the difficulty in improvement of nutritional status and inflammatory parameters in diabetic patients during at least the first year of CAPD compared to non‐DM patients.     

Extracellular Water Excess and Increased Self-Reported Fatigue in Chronic Hemodialysis Patients

Hemodialysis patients (HD) commonly report fatigue. Muscle wasting (sarcopenia) and extracellular water (ECW) excess have been reported to be associated with fatigue in other conditions. We wished to determine whether muscle loss and ECW excess were associated with fatigue in HD patients. Patients completed the Multidimensional Fatigue Inventory (MFI), Beck Depression Inventory-II (BDI-II), Patient Health Questionnaires (PHQ-9) and recorded their post-dialysis recovery time. Sessional dialysis data were recorded along with pre- and post-dialysis multi-frequency bioimpedance assessments (MFBIA). One hundred and ten patients, median age 64 (52–79) years, 67% male, 35% diabetic completed questionnaires and had pre- and post-HD MFBIAs. Median total MFI score was 60 (48–72), with the physical domain having the highest score. Modal (30.8%) recovery time post-dialysis was 1–4 h. Of the participants, 35% and 34% had increased BDI-II and PHQ-9 scores, respectively. Total MFI score was associated with increased BDI-II (>16) (standardized (Std) β 0.54, P < 0.001), PHQ-9 (>10) scores (Std β 0.49, P < 0.001, past history of depression (Std β 0.28, P = 0.003), post-HD ECW/total body water ratio (Std β 0.25, P = 0.002), recovery time > 8 h (Std β 0.26, P = 0.001), post dialysis mean arterial pressure (MAP) (Std β −0.19, P = 0.02), and muscle wasting (Std β −0.15, P = 0.05). Self-reported fatigue in HD patients is associated with self-reported depression, but also dialysis-related factors including increased ECW post HD, low MAP, and longer recovery times. Patients with reduced muscle mass were less likely to report fatigue, possibly accepting physical limitations. As such, interventions to reduce fluid overload and improve dialysis experience may help improve fatigue.     

Long-term on-line hemodiafiltration reduces predialysis beta-2-microglobulin levels in chronic hemodialysis patients

BACKGROUND: Hemodiafiltration (HDF) is effective in delaying the surgical need for carpal tunnel syndrome in chronic hemodialysis patients, however, predialysis beta(2)-microglobulin levels were not reduced in most short-term studies. The aim of this study was to assess the effect of long-term and differing frequencies of on-line HDF on serum beta(2)-microglobulin levels in comparison to high-flux hemodialysis (HD). METHODS: One hundred and twelve patients in the Chang Gung Memorial Hospital Dialysis Unit were divided into three groups to receive different frequencies of on-line HDF alternating with high-flux HD. Group 1 was treated once with HDF and twice with high-flux HD per week (n = 21). Group 2 was treated twice with HDF and once with high-flux HD per week (n = 33). Group 3 was treated with HDF three times per week (n = 58). Analysis was performed to compare the serum beta(2)-microglobulin levels in these groups and to high-flux HD. RESULTS: After receiving HDF for a mean of 7.9 months, group 3 patients had a reduced predialysis beta(2)-microglobulin level (22.2 +/-5.3 vs. 34.8 +/-6.3 mg/l, p < 0.001), postdialysis beta(2)-microglobulin level (6.3 +/- 2.0 vs. 13.8 +/- 6.8 mg/l, p < 0.001) and an increased beta(2)-microglobulin reduction rate (76.1 +/- 5.6 vs. 61.1 +/- 13.3%, p = 0.03) when compared to high-flux HD. A significant improvement in URR (p = 0.0004), Kt/V (p = 0.0002) and TAC urea levels (p = 0.006) but not nPCR (p = 0.122) was found after patients had been treated with on-line HDF. The beta(2)-microglobulin reduction rate was positively correlated with the overall volume of the replacement solution per session (p < 0.0001). Patients in group 3 had lower predialysis beta(2)-microglobulin levels than those in group 1 and group 2 (22.2 +/- 5.3 vs. 25.2 +/- 7.2 vs. 26.0 +/- 4.2 mg/l, p = 0.02). Furthermore, an inverse correlation was found between the predialysis beta(2)-microglobulin level and the duration of HDF, if patients were treated for more than 12 months (p = 0.031). CONCLUSION: On-line HDF has an increased dialysis efficiency compared to high-flux dialysis. Long-term HDF further reduced predialysis beta(2)-microglobulin levels, thus, it may provide an improved modality for renal replacement therapy.     

Coronary artery injection technique: A quantitative in vivo investigation using modern catheters

To date, there have been no quantitative in vivo assessments of contrast volumes and injection rates using modern high flow catheters during coronary angiography. Contrast volumes (n = 554), injection durations (n = 563), and injection rates (n = 498) were collected during 88 cardiac catheterizations. With increasing cathetersize (6, 7, and 8 French), injection volume increased (P < 0.0001), duration decreased (P < 0.0001), and rate increased (P < 0.0001). Compared with injections into the right coronary artery, left coronary artery injections were larger (7.1 ± 0.1 cc vs. 4.8 ± 0.1 cc, p < 0.0001), longer (3.6 ± 0.05 sec vs 3.0 ± 0.07 sec, P < 0.0001) and faster (2.1 ± 0.04 cc/sec vs. 1.7 ± 0.06 cc/sec, P < 0.0001). Patients with a significant stenosis in the left main or proximal right coronary artery received less contrast (P < 0.0001) more slowly (P < 0.0001) over a similar duration of injection (P = NS). When collaterals arose from the injected artery, angiographers injected more contrast (P < 0.001) over a longer period (P < 0.0001) more slowly (P < 0.0001). Catheter size and the injected vessel's location and anatomy significantly affect coronary catheterization injection technique. Cathet. Cardiovasc. Diagn. 44:34-39, 1998. © 1998 Wiley-Liss, Inc.     

Comparison of Solute Removal Properties Between High‐Efficient Dialysis Modalities in Low Blood Flow Rate

Blood flow (Qb) is one of the dialysis parameters most strongly influencing the performance of dialysis modalities. However, few studies have compared different dialysis modalities in patients with low Qb. We conducted a prospective, single‐center study in 21 patients. Each patient underwent four dialysis sessions with routine dialysis parameters: high‐flux hemodialysis (HD), predilution hemodiafiltration (pre‐HDF), expanded HD (HDx), and postdilution HDF (post‐HDF). The removal ratios (RR) of urea, creatinine, ß₂‐microglobulin, myoglobin, prolactin, α₁‐microglobulin, free kappa and lambda immunoglobulin light chains (?FLC and λFLC), α₁‐acid glycoprotein, and albumin were compared intraindividually. A proportional part of the dialysate was collected to quantify albumin loss. There were no differences in urea and creatinine RRs. The β₂‐microglobulin RR was higher in pre‐HDF and post‐HDF. Myoglobin and prolactin RRs were higher with HDx and post‐HDF. The α₁‐microglobulin and α₁‐acid glycoprotein RRs were significantly higher with post‐HDF than with other treatments, and RRs obtained with HDx were higher than obtained with HD and pre‐HDF. Free ?FLC and λFLC RRs showed the following results in ascending order: HD, pre‐HDF, HDx, and post‐HDF, most of them with statistical significance. Albumin loss varied from 0.45 g with HD to 3.5 g with post‐HDF. The global removal score values were 41.0 ± 4.8% with HD, 44.0 ± 5.2% with pre‐HDF, 49.5 ± 4.6% with HDx, and 54.8 ± 5.3% with post‐HDF, with significant differences between all treatment modalities. In conclusion, this study confirms the superiority of post‐HDF over high‐flux HD, pre‐HDF, and HDx in patients with low Qb. HDx was the closest alternative to post‐HDF and was clearly superior to HD and pre‐HDF. Finally, pre‐HDF was also superior to HD. With this Qb, there was a higher risk of underdialysis, both diffusive and convective, especially in patients with a session duration of less than 5 h.     

Pilot Study to Detect Changes in Blood Flow in the External Auditory Meatus During Hemodialysis

Blood flow to internal organs is reported to fall during hemodialysis (HD). As such, noninvasive monitoring devices are required to detect changes in perfusion, which could then be used for therapeutic interventions. We report on a pilot study monitoring blood flow in the outer auditory meatus. We measured the maximum pulse wave amplitude and indicators of blood flow by analyzing red and green color changes in the outer auditory meatus from video recordings made using an otoscope fitted with a digital camera during HD treatments. We studied 61 patients, 43 (71.5%) male, mean age 64.9 ± 12.7 years. Weight fell from 72.8 ± 22.5 kg predialysis to 71.5 ± 22.1 kg postdialysis (P < 0.001). BP did not significantly change (predialysis 142 ± 29/67 ± 18 to 143 ± 25/68 ± 17 mm Hg postdialysis). The maximum pulse wave amplitude in the external auditory meatus fell from 0.21 (0.1–0.55) to 0.14 (0.04–0.4) after 90 min, P < 0.001, and remained low thereafter, and the change at the end of the dialysis session was associated with percentage weight loss (r = ?0.37, P = 0.003). Green and red pixel values did not change (predialysis 0.339 [0.333–0.345] to 0.302 [0.291–0.33] post, and 0.301 [0.293–0.328] predialysis to 0.339 [0.334–0.347] post, respectively). This pilot study showed that the maximum pulse wave amplitude measured in the external auditory meatus fell during the dialysis session, and that the fall was associated with fluid removal. This could potentially lead to the development of a monitoring device, which could fit in the ear and record during the dialysis session.     

Hemodialysis improves myocardial interstitial edema and left ventricular diastolic function in patients with end-stage renal disease: noninvasive assessment by ultrasonic tissue characterization

Congestive heart failure is the most common cause of mortality in patients with end-stage renal disease (ESRD). Ultrasonic tissue characterization with integrated backscatter offers a promising method for the noninvasive assessment of regional myocardial contractile performance and fibrosis. The aim of this study was to investigate the effect of hemodialysis (HD) on myocardial tissue characterization and left ventricular function in ESRD patients. We examined 26 patients with ESRD undergoing routine HD (age 63 ± 12 years, duration of HD 9.2 ± 3.2 years) and 30 patients with essential hypertension (HT; 60 ± 10 years). Routine echocardiographic parameters and the cyclic variation of ultrasonic integrated backscatter of the ventricular septum (CV-IBS) were measured. Left ventricular mass index was significantly larger in patients with ESRD than in those with HT (217 ± 56 vs 146 ± 45 g/m², P < 0.05). The indices for left ventricular diastolic function (E/A, the ratio of left ventricular peak early to late diastolic filling velocity; DT, the deceleration time of the early diastolic filling) and CV-IBS had deteriorated significantly in patients with ESRD before HD compared with those with HT (E/A, 0.6 ± 0.2 vs 0.9 ± 0.3, P < 0.05; DT, 228 ± 23 vs 184 ± 19 ms, P < 0.05; CV-IBS, 9.0 ± 1.3 vs 12.4 ± 0.9 dB, P < 0.05), possibly reflecting interstitial fibrosis. In patients with ESRD, HD reduced calculated left ventricular mass index by 19% (before HD, 217 ± 56 vs immediately after HD, 176 ± 45 g/m², P < 0.05) and CV-IBS by 19% (9.0 ± 1.3 vs 7.3 ± 1.1 dB, P < 0.05), that possibly reflected improvement of interstitial edema. HD also significantly improved indices for left ventricular diastolic function (E/A, 0.6 ± 0.2 vs 0.9 ± 0.2, P < 0.05; DT, 228 ± 23 vs 188 ± 21 ms, P < 0.05). HD improves myocardial interstitial edema and left ventricular diastolic function in patients with ESRD. Noninvasive assessment of ultrasonic tissue characterization is useful in defining the pathophysiological changes of ventricular myocardium in patients with ESRD. Received: December 17, 2001 / Accepted: April 19, 2002 Correspondence to O. Hirono     

On-line hemodiafiltration and high-flux hemodialysis: comparison of efficiency and cost analysis

With on-line hemodiafiltration (HDF), low molecular weight substances are predominantly cleared by diffusion while middle molecules such as ß2-microglobulin (ß2M), an amyloidogenic factor, are removed mainly by convection. The objectives of this study are to evaluate the cost-effectiveness and safety of on-line HDF with dialyzer reuse, and to compare HDF and high-flux hemodialysis (HD) with respect to ß2M removal, urea kinetics (Kt/V) and symptom relief in those patients having dialysis-related amyloidosis. Ten chronic HD patients were put on post-dilution HDF for a period of 14.2 ±7.1 months. The AK 100 ULTRA system was used for on-line preparation of substitution fluid. These patients were then switched over to high-flux HD for a period of 4.6 ±3 months. Dialyzers were reused up to 30 times to reduce the cost of HDF. All the patients were hemodynamically stable during both HDF and high-flux HD treatments. No febrile reactions were reported. The percentage reduction of ß2M during HDF was significantly higher when compared with high-flux HD (75 ±4% vs 51 ±7%, p < 0.001). After 14.2 ±7.1 months of HDF, the patients had significant reduction of both the pre-dialysis ß2M level (47.4 ±7.9 μg/mL vs 28.2 ±4.9 μg/mL, p < 0.01) and post-dialysis ß2M level (11.4 ±2.8 μg/mL vs 6.8 ±1.0 μg/mL, p < 0.01). eKt/V achieved by HDF was significantly higher than that achieved by high-flux HD (1.94 ±0.26 vs 1.75 ±0.23, p < 0.01). Those patients with dialysis arthropathy and carpal tunnel syndrome had decreased joint pain and hand numbness respectively after putting on HDF but symptoms recurred while on high-flux HD. There were no statistical significant differences in the percentage reduction of ß2M, ß2M clearance, urea clearance and eKt/V with dialyzer reuse, and no adverse patient reactions had been recorded.ConclusionOn-line HDF has been proven to be a safe and reliable treatment. The clearance of ß2M and urea are significantly increased by HDF when compared with high-flux HD, and the increase in clearance of ß2M is sustained throughout the HDF treatment period. Symptoms of dialysis-related amyloidosis are improved by HDF. Dialyzer reuse, which reduces the cost of HDF by 30%, is feasible and safe.