Survival with short‐daily hemodialysis: Association of time,site, and dose of dialysis

In thrice‐weekly hemodialysis, survival correlates with the length of time (t) of each dialysis and the dose (Kt/V), and deaths occur most frequently on Mondays and Tuesdays. We studied the influence of t and Kt/V on survival in 262 patients on short‐daily hemodialysis (SDHD) and also noted death rate by weekday. Contingency tables, Kaplan‐Meier analysis, regression analysis, and stepwise Cox proportional hazard analysis were used to study the associations of clinical variables with survival. Patients had been on SDHD for a mean of 2.1 (range 0.1–11) years. Mean dialysis time was 12.9 ± 2.3 h/wk and mean weekly stdKt/V was 2.7 ± 0.5. Fifty‐two of the patients died (20%) and 8‐year survival was 54 ± 5%. In an analysis of 4 groups by weekly dialysis time, 5‐year survival continuously increased from 45 ± 8% in those dialyzing <12 hours to 100% in those dialyzing >15 hours without any apparent threshold. There was no association between Kt/V and survival. In Cox proportional hazard analysis, 4 factors were independently associated with survival: age in years Hazard Ratio (HR)=1.05, weekly dialysis hours HR=0.84, home dialysis HR=0.50, and secondary renal disease HR=2.30. Unlike conventional HD, no pattern of excessive death occurred early in the week during SDHD. With SDHD, longer time and dialysis at home were independently associated with improved survival, while Kt/V was not. Homedialysis and dialysis 15+ h/wk appear to maximize survival in SDHD.     

Assessment of subjective and hemodynamic tolerance of different high‐ and low‐flux dialysis membranes in patients undergoing chronic intermittent hemodialysis: A randomized controlled trial

Clinical experience and experimental data suggest that intradialytic hemodynamic profiles could be influenced by the characteristics of the dialysis membranes. Even within the worldwide used polysulfone family, intolerance to specific membranes was occasionally evoked. The aim of this study was to compare hemodynamically some of the commonly used polysulfone dialyzers in Switzerland. We performed an open‐label, randomized, cross‐over trial, including 25 hemodialysis patients. Four polysulfone dialyzers, A (Revaclear high‐flux, Gambro, Stockholm, Sweden), B (Helixone high‐flux, Fresenius), C (Xevonta high‐flux, BBraun, Melsungen, Germany), and D (Helixone low‐flux, Fresenius, Bad Homburg vor der Höhe, Germany), were compared. The hemodynamic profile was assessed and patients were asked to provide tolerance feedback. The mean score (±SD) subjectively assigned to dialysis quality on a 1–10 scale was A 8.4 ± 1.3, B 8.6 ± 1.3, C 8.5 ± 1.6, D 8.5 ± 1.5. Kt/V was A 1.58 ± 0.30, B 1.67 ± 0.33, C 1.62 ± 0.32, D 1.45 ± 0.31. The low‐ compared with the high‐flux membranes, correlated to higher systolic (128.1 ± 13.1 vs. 125.6 ± 12.1 mmHg, P < 0.01) and diastolic (76.8 ± 8.7 vs. 75.3 ± 9.0 mmHg; P < 0.05) pressures, higher peripheral resistance (1.44 ± 0.19 vs. 1.40 ± 0.18 s × mmHg/mL; P < 0.05) and lower cardiac output (3.76 ± 0.62 vs. 3.82 ± 0.59 L/min; P < 0.05). Hypotension events (decrease in systolic blood pressure by >20 mmHg) were 70 with A, 87 with B, 73 with C, and 75 with D (P < 0.01 B vs. A, 0.05 B vs. C and 0.07 B vs. D). The low‐flux membrane correlated to higher blood pressure levels compared with the high‐flux ones. The Helixone high‐flux membrane ensured the best efficiency. Unfortunately, the very same dialyzer correlated to a higher incidence of hypotensive episodes.     

Monthly continuous erythropoietin receptor activator treatment maintains stable hemoglobin levels in routine clinical management of hemodialysis patients

Once-monthly administration of CERA, a continuous erythropoietin receptor activator, has shown equivalent efficacy to shorter-acting erythropoiesis-stimulating agents (ESAs) that require more frequent dosing, but data on routine use of once-monthly CERA in hemodialysis patients are lacking. Study on Efficacy, Safety and Applicability of Mircera (SESAM) was a prospective, multicenter, noninterventional trial with a duration of up to 9 months (month 0-5 "titration phase"; month 6-8 "evaluation phase") to test the stability of Hb control in hemodialysis patients under routine conditions. Patient selection, Hb targets and CERA dosing were at the discretion of the local nephrologist. 918 patients from 92 German nephrology centers were included. Ninety-three percent were on ESA treatment prior to study entry. The mean number of CERA dose changes during the study was 1.9 ± 1.9 per patient. Mean Hb level was 11.4 ± 1.2 g/dL at baseline and 11.7 ± 1.4 g/dL at the end of the 8-month study. During the evaluation phase (months 6-8), 15.6%, 40.3%, and 66.0% of patients had stable Hb (i.e., at least two values) in the ranges 11-12, 10-12, and 10-13 g/dL, respectively. The mean intra-individual fluctuation in Hb was 1.4 ± 0.7 g/dL during the study (0.5 ± 0.4 g/dL during the 3-month evaluation phase). More than 90% of patients, and > 80% of physicians, rated CERA therapy as "very good" or "good" throughout the study. Four patients (0.4%) discontinued prematurely due to adverse drug reactions. Once-monthly CERA therapy maintains stable Hb values with low intra-individual variability and few dose adaptations in hemodialysis patients when administered entirely according to local practice, and the regimen was well-tolerated.     

Exceeding hemoglobin target levels in US hemodialysis patients receiving epoetin, 1999 to 2002

Despite emerging concerns that exceeding anemia targets with erythropoiesis stimulating agents may be risky for hemodialysis patients, the magnitude of and risk factors for the problem have received little attention, particularly regarding year-to-year comparisons. We studied monthly hemoglobin and epoetin levels in 41,101 patients aged at least 65 years who initiated hemodialysis between 1999 and 2002, with upper targets defined by hemoglobin levels of 120 and 130 g/L, respectively. While baseline hemoglobin values and epoetin doses rose from year to year, their rates of change during follow-up declined (p<0.0001). Similar patterns were seen after reaching hemoglobin levels of 110 g/L; comparing 1999 to 2002, the proportions reaching 120 and 130 g/L in the ensuing 9 months increased from 90% to 96% (p<0.0001) and from 56% to 69%, respectively (p<0.0001). Multivariate analysis showed that, while more recent years of dialysis inception and initial epoetin dose were associated with all 3 outcomes, higher baseline hemoglobin levels were associated with reaching levels of 110 and 120 g/L, but not 130 g/L. Exceeding hemoglobin level targets has become widespread in the United States and is associated with changes in epoetin dosing practices.     

Changes in hemoglobin and albumin concentration during nocturnal home hemodialysis

The hemoglobin (Hb) and the serum albumin (S.Alb) concentration commonly rise during seated, conventional thrice-weekly 4 to 4.5 hr hemodialysis (CHD) as a result of rapid fluid removal from the intravascular compartment. Conversely, in long, slow, recumbent nocturnal home hemodialysis (NHHD), the intra-dialytic S.Alb concentration has been shown to fall. In normal human physiology, plasma volume expansion rapidly follows recumbency and is sustained until a resumption of an upright position re-induces plasma volume contraction. The plasma protein dilution of recumbency has been suggested as the mechanism behind this finding in NHHD. Our retrospective analysis of 585 consecutive measurements of predialysis and postdialysis S.Alb and Hb taken from 71 NHHD patients confirmed an intra-dialytic fall in S.Alb (0.99% in alternate night NHHD and 1.4% in 6 nights/week NHHD) compared with an 8.4% rise in a control group of 104 CHD patients (p<0.001). Although the NHHD intra-dialytic Hb rose (3.8% in alternate night NHHD and 2.6% in 6 nights/week NHHD), this rise was significantly greater (8%) in CHD patients (p<0.001), and as physiological data confirm that recumbent dilution for albumin is greater than that for Hb, this may provide the explanation. We conclude that NHHD provides a more physiological volume milieu with the normal physiological dilution mechanisms of recumbency still operating despite the slow, steady volume reduction that accompanied longer hour and more frequent dialysis. These mechanisms are subverted, however, in CHD by the more-aggressive plasma contraction needed to attain adequate control of the intravascular volume in the face of shorter hour, less-frequent dialysis.     

Infective spondylodiscitis in patients on high‐flux hemodialysis and on‐line hemodiafiltration

Infective spondylodiscitis (ISD) is a rare but potentially devastating condition in hemodialysis (HD) patients. Reports are limited especially in patients receiving high‐flux HD and hemodiafiltration (HDF). In a retrospective analysis, 13 patients on our maintenance high‐flux HD/HDF program were identified as having has infective spondylodiscitis over a 10‐year period (1997–2006), an incidence of approximately 1 episode every 215 patient‐years. The incidence was around 3 times higher in patients dialyzing with tunnelled central venous catheters (TCVC) than in those with arteriovenous fistulae. Affected patients were elderly (mean age 70 years) and had multiple comorbidities. Access problems, particularly TCVC infection, were common in the months preceding it's onset. Tunnelled central venous catheter removal during these episodes did not necessarily prevent it. Diagnosis was based on a history of back pain, raised C‐reactive protein, positive blood cultures, and characteristic magnetic resonance findings. Many patients were apyrexial and had normal white cell counts. In our patients on high‐flux HD/hemodiafiltration, its incidence appears comparable to that in conventional HD settings. No patients had infection with waterborne organisms. Blood cultures were positive in 77%. Gram‐positive organisms predominated, particularly Staphylococcus aureus. The major route of infection was hematogenous, with the most likely source the venous access. All received antibiotics for 6 to 12 weeks or until death. Only 2 patients underwent surgical drainage. Mortality was high (46%) and predicted by the development of complications, and by pre‐existing cardiovascular comorbidity. Prevention, using strategies to reduce the prevalence of bacteremia, including limiting the use of TCVC, should be an overriding aim.     

Impact of advanced dialysis technology on the prevalence of dialysis‐related amyloidosis in long‐term maintenance dialysis patients

Dialysis‐related amyloidosis (DRA) is a unique type of amyloidosis (beta‐2 microglobulin) predominantly in end‐stage renal disease. Its clinical manifestations add to increased morbidity and reduced quality of life. There seems to be a relative risk reduction in DRA manifestations when hemodialysis (HD) patients are treated with advanced HD technology, but changes of the course of DRA are uncertain. The aim of our investigation was to evaluate the prevalence and severity of carpal tunnel syndrome (CTS) in long‐term dialysis patients receiving either conventional or high‐flux, online‐produced ultrapure dialysis fluid. The cross‐sectional study included 147 HD patients (at least 10 years). The definitive diagnosis of CTS was made histologically or by the coexistence of CTS with other radiological DRA manifestations (bone cysts, arthropathies). The two HD patient groups did not differ significantly in age at start of HD, gender, major co‐morbid diseases, anuria, and dialysis vintage. The conventional HD group had significantly higher circulating beta‐2 microglobulin and C‐reactive protein (CRP) levels. The prevalence of DRA was 68% for the conventional HD group and 28% for the advanced HD group. Duration of dialysis treatment was the only significant risk factor for the development of clinical DRA manifestations in both study groups, but CTS, bone cysts, or arthropathies occurred significantly earlier in conventional HD patients. The prevalence and severity of DRA have decreased with advances in dialysis technology during the last two decades, although its occurrence is simply delayed.     

Dialysis adequacy and nutritional status of hemodialysis patients

To characterize the nutritional status of renal failure patients and its relationship with hemodialysis adequacy measured by Kt/V, a study was carried out with a population of 44 adult patients with renal failure and mean age 51+/-15 years. Anthropometric data, such as dry weight, height, arm circumference, triceps skinfold thickness, mid-arm muscle circumference, and body mass index were assessed, and biochemical tests were conducted for urea, potassium, creatinine, serum albumin, and phosphorus levels, in addition to hemogram and quarterly urea reduction rate average (Kt/V). In order to evaluate calorie intake, a dietary questionnaire on habitual daily food ingestion was administered, taking into consideration the hemodialysis date. The patients were divided into 2 separate groups for the statistical analysis, with 50% of the patients in each group: A (Kt/V<1.2) and B (Kt/V>1.2). The data were tabulated as mean and standard deviation, with differences tested by Student's t test. The correlations between variables were established by the coefficient p of Pearson. Most of the patients (43%) were considered eutrophic, based on the BMI, and presented inadequate calorie intake, corresponding to 88.5+/-24% (30.8 kcal/kg actual weight) of the total energy required and adequate protein intake, reaching 109.9+/-40% of the recommended daily allowance (1.24 g/kg of actual weight). There was a correlation of Kt/V with anthropometric parameters such as body mass index, arm circumference, and mid-arm muscle circumference. The biochemical parameters related to dialysis adequacy were albumin, ferritin, and urea (predialysis). Well-dialyzed patients presented better levels of serum albumin. There was an influence of gender and age on correlations of the analyzed variables. Female and younger patients presented better dialysis adequacy. The dialysis adequacy was related to the nutritional status and influenced by the protein intake and body composition. Gender and age had an important influence in the dialysis adequacy, as men presented lower dialysis adequacy and younger adults presented better dialysis adequacy. Further research is necessary to understand better how to facilitate effective and efficient techniques for the nutritional status assessment of hemodialysis patients.     

Perihospitalization patterns of hemoglobin levels and erythropoiesis‐stimulating agent doses in US hemodialysis patients, 1998–2009

Anemia management in hemodialysis patients is of primary importance for clinicians and dialysis providers. Through a retrospective claims analysis, we studied prevalent US hemodialysis patients 1998–2009, and examined patterns of hemoglobin levels and erythropoiesis‐stimulating agent (ESA, epoetin [EPO], and darbepoetin [DPO] ) doses surrounding hospitalization events. Medicare outpatient claims were used to determine monthly ESA doses and associated hemoglobin levels. ESA dose trajectories were defined with repeated measures models incorporating an autoregressive covariance matrix that compared subsequent measurements with the index month of hospitalization, with variance component covariance matrices chosen for pair‐wise comparisons. Regarding prehospitalization hemoglobin levels, a biphasic pattern occurred in both the EPO (1998–2009, n = 161,242) and DPO (2004–2009, n = 4391) populations; levels rose from 1998 to 2004, fell thereafter in the EPO population, and fell after 2006 or 2007 in the DPO population. In the EPO population, the proportions of patients with hemoglobin less than 10 g/dL were 30.1% in 1998, 14.5% in 2004, and 28.3% in 2009; corresponding values for the DPO population were 21.0% in 2004 and 31.6% in 2009. While some degree of year‐to‐year variability occurred, EPO dose trends were less pronounced, with an apparent peak in 2004 followed by a modest decline; trends were similar for DPO. Trends in EPO dose trajectories did not completely parallel those for hemoglobin level; while EPO doses increased yearly up to 2004, doses stabilized, but did not materially decrease after 2004. No definite annual trends for DPO dose trajectories were apparent.     

Clinical benefits of ultrapure dialysis fluid for hemodialysis

Ultrapure dialysis fluid contains less than 0.1 CFU/mL and 0.03 EU/mL and can be prepared by ultrafiltration of standard‐quality dialysis fluid. Today, the use of ultrapure dialysis fluid is widely recommended based on our awareness of potential transfer of bacterial products across dialysis membranes. Early observations associated improved fluid quality with reduced incidence of the carpal tunnel syndrome, but provided no proof of mechanism. Recent clinical studies in hemodialysis patients have shown that the introduction of ultrapure dialysis fluid brings about significant improvements in a number of inflammation‐related parameters. Levels of C‐reactive protein and IL‐6 are reduced, anemia management is achieved using less EPO or reaching higher hemoglobin levels, nutritional indices are improved, and β₂‐microglobulin levels have been observed to decline, when ultrapure dialysis fluid is used in comparison with standard‐quality fluid. In addition, some studies have documented reduced levels of advanced glycation end products and delayed decline of residual renal function in patients using ultrapure dialysis fluid. Although further evidence is needed before we can assess the long‐term benefits associated with improved fluid quality, there should be sufficient data available today to support our efforts toward gradual improvement of the microbiological quality of dialysis fluid.     

Gustatory sweating recurring on peritoneal dialysis but resolving during periods of hemodialysis

Gustatory sweating is a rare disorder characterized by profuse sweating on the forehead, face, scalp, and neck occurring soon after ingesting food, which has been reported in diabetic patients. The mechanism is thought to be triggered by taste buds and not gastric stimulation. We report a case where gustatory sweating repeatedly developed on peritoneal dialysis that resolved on periods of hemodialysis. A 32-year-old woman with diabetic end-stage renal disease developed gustatory sweating shortly after beginning continuous ambulatory peritoneal dialysis despite excellent clearances. After 5 months, she changed to hemodialysis for 2 months and noticed complete resolution of her gustatory sweating; however, after her return to peritoneal dialysis 2 months later, her gustatory sweating recurred. While on peritoneal dialysis, she was treated with clonidine, which resulted in improvement but not resolution of her symptoms as had occurred on hemodialysis. Another period on hemodialysis resulted in the resolution of her symptoms that returned again after restarting peritoneal dialysis. Clonidine provided incomplete relief while topical glycopyrrolate was effective and without complications. We report recurrent gustatory sweating on peritoneal dialysis that resolved with hemodialysis. We have no data to suggest that intra-abdominal stimulation played a role, but rather that despite excellent clearances neuropathy may have played a role. Treatment with topical glycopyrrolate may be safe and effective given every third day if clonidine is ineffective.     

Dialysate saving by automated control of flow rates: comparison between individualized online hemodiafiltration and standard hemodialysis

Cost reduction and quality improvement seem to be conflicting issues. However, online hemodiafiltration (oHDF) with new automatic functions offers a cost‐efficient therapy compared to hemodialysis (HD). Seven dialysis centers conducted a randomized clinical trial with cross‐over design: high‐flux HD vs. postdilutional oHDF with functions coupling both dialysate and substitution flow rates to blood flow rates. During the 6 weeks of the study, all treatment parameters remained unchanged for HD and oHDF, apart from dialysate and substitution flow rate. Treatment data were recorded during each treatment, and predialytic and postdialytic concentrations of urea were recorded at the end of each study phase. The analysis involved 956 treatments of 54 patients. The mean dialysate consumption was 123.2 ± 6.4 l for HD and 113.4 ± 14.9 l for oHDF (p < 0.0001), the mean dialysis dose was 1.42 ± 0.23 for HD and 1.47 ± 0.26 for oHDF (p < 0.0001); oHDF resulted in a lower dialysate consumption (8.0% less) and a slightly increased dialysis dose (Kt/V 3.5% higher) compared to HD. oHDF with the investigated automatic functions offers substantial savings in dialysate consumption without decreasing dialysis dose.     

微孔膜的可压缩性及参数变化对膜蒸馏跨膜传质速率的影响

针对两种聚四氟乙烯膜在膜两侧压差为10～100kPa范围内进行了气体渗透实验,结果表明：实验用膜具有一定的可压缩性,随膜两侧压差的增大,膜孔径r减小,而膜孔隙率与有效厚度的比值ε／τδ是增大的,且其变化幅度随膜厚度的增大而增大,通过求解数学模型方程得到了不同膜参数时直接接触式膜蒸馏和真空膜蒸馏跨膜传质速率的预测值,与相同条件下的膜蒸馏实验测定的传质速率进行对比,结果表明：由膜的可压缩性带来的膜参数变化能够使跨膜传质速率有所增长,采用相近压差下气体渗透实验测定的膜参数能够较准确地预测膜蒸馏的跨膜传质速率。     

Association between patient psychosocial characteristics and receipt of in‐center nocturnal hemodialysis among prevalent dialysis patients

Introduction: Compared to traditional in‐center hemodialysis (HD), in‐center nocturnal dialysis (INHD) is characterized by longer sessions and nighttime administration, which may lead to better outcomes for some patients. Given the importance of patient choice in the decision to initiate INHD, we explored associations between patients’ psychosocial characteristics and their receipt of INHD. Methods: Among hemodialysis patients at a medium‐sized dialysis organization, we identified INHD patients as those for whom ≥80% of dialysis sessions were INHD sessions—starting at 6:30 pm or later and lasting ≥5 hours—over the 3 months (≥20 sessions total) after their first INHD session. We extracted dialysis session data from electronic medical records and psychosocial data from social worker assessments. We tested associations of patients’ psychosocial characteristics—as well as demographic and clinical characteristics—with INHD receipt among all hemodialysis patients (INHD and HD) in bivariate analyses and multivariable logistic regression models. Findings: Among 759 patients with complete data, we identified 47 (6.2%) as INHD patients. On average, these patients were more likely than HD patients to be employed (full‐time 10.6% vs. 5.2%; part‐time 17.0% vs. 4.2%; P < 0.001), and they were significantly less likely to require ambulatory assistance (14.9% vs. 39.6%, P < 0.001). In multivariable regressions, we found that part‐time employment (versus being unemployed) was associated with a 7.1 percentage‐point higher likelihood of being an INHD patient (P = 0.01), and the negative association with ambulatory assistance needs approached statistical significance (P = 0.056). No other psychosocial factors included in this main regression analysis were statistically significantly associated with INHD patient status. Discussion: Researchers comparing the outcomes of patients undergoing INHD versus other treatment modalities will need to account for differences in employment status—and other factors like requiring ambulatory assistance and age which may predict the ability to work—between INHD users and comparison patients to avoid bias in estimates.     

膜生物反应器中临界通量理论的研究

膜污染是影响膜生物反应器大规模化应用的重要因素之一,而膜生物反应器在低于临界通量运行时能有效减缓膜污染.介绍了临界通量理论的概念、测定方法、产生机理和影响因素,并对各影响因素间的相互关系做了探讨.其中临界通量概念有强弱两种形式,膜生物反应器工艺应用的主要为弱形式的临界通量;临界通量的测定方法主要包括流量阶梯法、压力阶梯法和滞后效应法等;临界通量存在的机理可归结于活性污泥粒子所受的趋向于膜表面的拖曳力与粒子的返混作用达到了平衡,而拖曳力与返混力的大小主要与膜与膜组件特性、混合液性质及操作条件有关,且各个因素间相互影响.     

The role of dialyzer membrane flux in bio-incompatibility

Dialyzer membrane flux is currently defined according to beta(2)-microglobulin (a middle molecule) clearance. Traditionally, high flux membranes were synthetic, and caused less inflammatory reaction in the extracorporeal circuit, compared with standard low-flux cuprophan bio-incompatible dialyzers. Initial reports suggested improved patient outcomes in acute renal failure when noncuprophan dialyzer membranes were used. However, over time these positive observations have not been substantiated. As the price differential between these dialyzer membrane types has become marginal, more high-flux dialyzers are now used in routine clinical practice. Two multicenter trials have recently reported a survival advantage for high-flux dialyzers. Whether this is directly consequent upon the choice of dialyzer membrane, or related to improvements in dialysate water quality, or changes in other clinical practices remains to be determined.     

Effect of ethnicity on erythropoietin therapy response for hemodialysis patients: A retrospective study

Anemia is a common feature in chronic kidney disease patients due to deficiency of erythropoietin (EPO). Diseased kidneys are unable to produce EPO, which enhances red blood cell production from the bone marrow. Recombinant human EPO in hemodialysis patients was introduced with perfect outcomes as a hormonal substitutive treatment. Some ethnic minority groups have high prevalence of anemia associated with chronic kidney diseases. The aim of this study is to evaluate the differences between African Caribbeans and Caucasians’ EPO therapy response with regard to hemoglobin (Hb), some factors affecting it and some comorbid conditions. A retrospective study for 6 months of 100 patients on hemodialysis was conducted on two ethnic minorities groups; 46 patients were African Caribbean and 54 patients were Caucasian, who received EPO therapy at once or three times weekly dose at the Hanbury Dialysis Unit of Royal London Hospital. There were three types of EPO therapy used: Aranesp, Mircera and Neorecormon. Forty‐six patients were African Caribbean and 54 patients were Caucasian. There were 63.4% of patients treated by Aranesp while 13% were given Mircera; 22.8% of the sample used Neorecorman. It was shown that the chosen comorbid conditions had higher percentage in the African Caribbeans than in Caucasians. Diabetic and/or hypertensive patients are almost double the patient numbers. In addition, sickle cell anemia is only present in African Caribbeans. There were 43.5% of African Caribbeans and 81.1% of Caucasians who met the standards of Hb level. There was no significant difference between African Caribbeans and Caucasians regarding parathyroid hormone, c‐reactive protein, B12, mean corpuscular volume, ferritin, and folate. In this study, there was a significant difference in the Hb levels between African Caribbean and Caucasian groups. Sixty percent of African Caribbeans had mean Hb less than normal levels. However, they received lower EPO dose than Caucasians. As a result, this may affect the whole treatment and therapy which may lead to anemic complications.     

Post‐hemodialysis dosing of 1 vs. 2 g of ceftazidime in anuric end‐stage renal disease patients on low‐flux dialysis and its pharmacodynamic implications on clinical use

Ceftazidime is a cost‐effective antimicrobial against Gram‐negative pathogens associated with sepsis in end‐stage renal disease (ESRD) hemodialysis patients with potential for wider use with the advent of ceftazidime‐avibactam. Dosing ceftazidime post‐hemodialysis appears attractive and convenient, but limited in vivo data on pharmacodynamic efficacy (PE) attainment, defined as >70% of the interdialytic period drug concentrations exceed susceptible pathogens minimal inhibitory concentrations (MICs) (%TMIC), warrants further assessment. We therefore evaluated PE and tolerability of 1 against 2 g regime in anuric ESRD patients on low‐flux hemodialysis. Two doses of 1 or 2 g ceftazidime were administered post‐hemodialysis prior to 48‐ and 72‐hour interdialytic intervals in ESRD inpatients without active infections. Peak and trough concentrations (mg/L) were assayed using a validated liquid chromatography–tandem mass spectrometry method. Proportion of patients achieving PE for known pathogens with MICs ≤ 8 mg/L and adverse effects were assessed. Six (43%) and eight (57%) adult patients received 1 and 2 g dose, respectively. Median (25th–75th percentile), peak, 48‐ and 72‐hour trough ceftazidime concentrations were 78 (60–98) vs. 158 (128–196), 37 (23–37) vs. 49 (39–71), and 13 (12–20) vs. 26 (21–41) mg/L, respectively, resulting in 100% TMIC for both doses. One patient on the 1‐g dose experienced mild pruritus. Reliable and safe PE attainment over both 48‐ and 72‐hour interdialytic interval was achievable with 1 g of ceftazidime dosed post‐hemodialysis. The 2 g dose was equally effective and well tolerated but may not be necessary. These findings need validation in non‐anuric patients, high‐flux hemodialysis, and during avibactam co‐administration.     

聚偏氟乙烯中空纤维医用膜的研制

利用非溶剂相转化法,制备不同聚偏氟乙烯(PVDF)改性膜.研究PVDF与聚乙二醇(PEG)-400固含量对膜性能的影响,并将PVDF改性膜与市售血液透析膜F60S的性能进行了对比分析.结果表明,随着PVDF固含量的增加,膜分离孔径和纯水通量逐渐减小,BSA截留率和机械性能提高;随着PEG-400固含量的增加,膜分离孔径先减小后增大,BSA截留率先增加后减小,纯水通量逐渐提高,机械性能下降.PVDF/PEG膜分离孔径与纯水通量比F60S膜略低,BSA截留率、机械性能、血液相容性与F60S膜相比均具优势.