Canadian Hemodialysis Morbidity Study

Dietary intake in hemodialysis patients does not reflect a heart healthy diet

OBJECTIVE

Cardiovascular disease is highly prevalent and has a major effect on morbidity and mortality in patients undergoing maintenance hemodialysis (MHD). Dietary factors that may contribute to cardiovascular disease have not been well studied in this population. We hypothesize that dietary intake in this population does not meet the guidelines for cardiovascular risk reduction.

DESIGN

A cross-sectional study was completed using the validated "Block Dialysis 1 Food Frequency Questionnaire" to assess dietary intake of MHD patients.

SETTING AND PATIENTS

A total of 70 patients undergoing MHD at our outpatient dialysis center completed the questionnaire under the supervision of a trained dietitian. The population consisted of 38 men and 32 women.

MAIN OUTCOME MEASURE

Dietary intake was the main outcome measure, with a focus on calories, soluble fiber, saturated fatty acid (SFA), unsaturated fatty acid intake (UFA), and protein.

RESULTS

The mean fiber intake was 10.77 (±5.87) g/day, and only 2 of 71 (2.9%) were in compliance with the recommended daily intake of >25 g/day. As percentage of total calories, of the 70 patients, 5 (7.1%) had a fat intake of <30%, 22 (31.4%) had SFA intake of <10%, 64 (91.4%) had a UFA of ≤30%, 22 (31.4%) had a protein-based diet of ≥15%, and 66 (94.3%) had a carbohydrate diet of <60%.

CONCLUSIONS

Most patients did not meet the dietary guidelines for reducing the risk of cardiovascular disease. Substituting UFA or soluble fiber for SFA improves low density lipoprotein (LDL) cholesterol levels without negative effects on other lipid parameters.

Left ventricular geometry and cardiovascular mortality based on haemodialysis patient autopsy analyses

AIM

In end-stage renal disease (ESRD) patients, left ventricular hypertrophy (LVH) is common and a risk for cardiovascular events. LVH is geometrically classified into two major groups, concentric and eccentric, and accumulating evidence suggests eccentric LVH has a more negative effect than concentric LVH on ESRD outcome. However, there have been very few studies on the cardiac findings from ESRD patient autopsy in which the relationship between LVH geometry and mortality was analyzed.

METHODS

An observational study was performed with the autopsy findings in 30 haemodialysis patient cases between 2001 and 2006 at Mitsui Memorial Hospital, Tokyo. Between those who died of a cardiovascular cause and those who died of non-cardiovascular causes, we compared the heart/bodyweight ratio, left ventricular dilatation, and the extent of fibrosis of the left ventricle.

RESULTS

Heart/bodyweight ratio was significantly higher (P < 0.0001) in the cardiovascular mortality group (n = 11, 11.7 +/- 2.5 g/kg) compared to the non-cardiac cause of death group (n = 19, 8.05 +/- 0.7 g/kg). The dilatation of the left ventricle was significantly more frequent in the cardiovascular than the non-cardiac cause of death group (P = 0.016). Additionally, the fibrotic area of left ventricular cross-section was larger in the cardiovascular (1.63 +/- 1.6%) than the non-cardiac group (0.83 +/- 1.7%, P = 0.04).

CONCLUSION

This autopsy study indicates that eccentric LVH in haemodialysis patients is closely associated with cardiovascular mortality. LVH geometry, as well as LVH severity, is worthy of consideration as a clinical predictor for cardiovascular mortality.

Perceived autonomy and self-esteem in Dutch dialysis patients: the importance of illness and treatment perceptions

Compared to healthy people, end-stage renal disease (ESRD) patients participate less in paid jobs and social activities. This study explored the perceived autonomy, state self-esteem and labour participation in ESRD patients on dialysis, and the role illness and treatment perceptions play in these concepts. Patients completed questionnaires at home or in the dialysis centre (N = 166). Data were analysed using bivariate and multivariate analyses. Labour participation among dialysis patients was low, the average autonomy levels were only moderate, and the average self-esteem level was rather high. On the whole, positive illness and treatment perceptions were associated with higher autonomy and self-esteem, but not with labour participation. Multiple regression analyses demonstrated that illness and treatment perceptions explained 18 to 27% of the variance in autonomy and self-esteem. Perceptions of personal control, less impact of the illness and treatment, and less concern were important predictors. Our results indicate that dialysis patients' beliefs about their illness and treatment play an important role in their perceived autonomy and self-esteem. Stimulating positive (realistic) beliefs and altering maladaptive beliefs might contribute to a greater sense of autonomy and self-esteem, and to social participation in general. Interventions focusing on these beliefs may assist patients to adjust to ESRD.

The impact of health care restructuring on nosocomially acquired blood stream infections

OBJECTIVE

To assess the impact of the health care restructuring, which occurred in Alberta in 1995, on the occurrence of nosocomial blood stream infection and risk factors for these infections at the University of Alberta Hospital.

PATIENTS AND METHODS

Changes in patient population, hospital bed numbers, admissions and hospital days for 1993 and 1994 (1993/94) were compared with those for 1996 and 1997(1996/97). Central venous catheter (CVC) use in intensive care units (ICU), days of total parenteral nutrition (TPN) and hemodialysis were compared for the two time periods. Prospectively collected data obtained by monitoring blood culture results on nosocomial blood stream infections in 1993/94 were compared with those obtained in 1996/97.

RESULTS

Hospital bed number fell by 10% between 1993/94 and 1996/97. Annual admissions fell by 19% and patient days by 17%. Some services markedly increased patient days (neurosurgery 49%, nephrology 30%, orthopedic surgery 24%), and others markedly reduced patient days (obstetrics and gynecology 99%, ophthalmology 100%, adult medicine 41%, general paediatrics 38%). ICU use of CVCs increased by 41%, TPN days increased by 25% and hemodialysis runs increased by 9%. Annual nosocomial blood stream infections increased by 31% and the annual rate per 10,000 patient days increased by 60%. TPN-related blood stream infection rates and ICU CVC infection rates did not change from 1993/94 to 1996/97.

CONCLUSIONS

Hospital restructuring has been associated with a 31% increase in nosocomial blood stream infection number and a 60% increase in rate. The increase has been associated with a change in patient populations and increases in risk factors for blood stream infection.

Risk factors associated with patency loss of hemodialysis vascular access within 6 months

BACKGROUND AND OBJECTIVES

Clinical guidelines support vascular access surveillance to detect access dysfunction and alter the clinical course by radiologic or surgical intervention. The objective of this study was to explore the association between loss of primary functional patency within 6 months of first use and demographic and clinical characteristics of patients receiving chronic renal replacement therapy with arteriovenous fistulas.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a retrospective study of all chronic hemodialysis patients followed by the Southern Alberta Renal Program from January 1, 2005 to June 30, 2008. Demographic and clinical variables and initial intra-access blood flow (IABF) were compared between those with and without loss of primary functional patency. To determine the contribution of independent variables to the dependant variable of loss of primary functional patency, a multivariable analysis using logistic regression was performed.

RESULTS

The incidence of primary failure was 10% (81 of 831). Multivariable analysis found that older age (>65 years, odds ratio [OR] 3.6, P < 0.001), history of diabetes (OR 2.3, P = 0.007), history of smoking (OR 4.3, P < 0.001), presence of forearm fistulas (OR 4.0, P < 0.001), and low initial IABF (<500 ml/min, OR 29, P < 0.001) were independently associated with loss of primary patency.

CONCLUSIONS

The set of patient risk factors identified in this study, particularly initial IABF, can be used to identify patients who are most at risk for developing vascular access failure and to guide a more directed approach for a vascular access screening protocol.

Infection of hemodialysis arteriovenous grafts

PURPOSE

Prosthetic arteriovenous grafts (AVG) are bedeviled by significant infectious complications. This study was to determine the infectious complications of prosthetic AVG and review the relevant literature.

METHODS

All prosthetic AVG inserted between January 2000 to December 2007 were studied. Data on age, sex, date of graft insertion, indication for AVG, site of graft insertion, date of graft related infection, treatment and outcome for graft and patients were analyzed.

RESULTS

There were 84 AVG inserted into 58 patients. Thigh AVG accounted for 55% of cases whereas upper arm AVG was inserted in 39%. Thirteen (17.3%) AVG were associated with one or more episodes of infection. The infection rate for SynerGraft (50%) was statistically significantly different from that of PTFE (12%) - Yates' x2=6.164; df=1; p=0.013. The rate of infection was higher for thigh grafts (9/37) compared to other sites (4/34), but the difference was not statistically significant (Yates' x2=1.123; df=1; p=0.289). Only one death was directly related to AVG infection in this series.

CONCLUSION

Infectious complications of AVG require prompt surgical or radiological intervention to save life or access. The need to excise an infected graft completely is sometimes counterbalanced by the compelling need to provide vascular access for hemodialysis in a patient with limited access options.

Inflammation as a cause of malnutrition, atherosclerotic cardiovascular disease, and poor outcome in hemodialysis patients

Cardiovascular disease (CVD) remains the major cause of morbidity and mortality in end-stage renal disease (ESRD) patients treated by hemodialysis (HD). Although traditional risk factors are common in dialysis patients, they may not alone be sufficient to account for the unacceptable high prevalence of CVD in this patient group. Recent evidence demonstrates that chronic inflammation, a nontraditional risk factor that is commonly observed in HD patients, may cause malnutrition and progressive atherosclerotic CVD by several pathogenetic mechanisms. The cause(s) of inflammation in HD patients is multifactorial and includes both dialysis-related (such as graft and fistula infections, bioincompatibility, impure dialysate, and back-filtration) and dialysis-unrelated factors. Although inflammation may reflect underlying CVD, an acute-phase reaction may also be a direct cause of vascular injury. Available data suggest that proinflammatory cytokines play a central role in the genesis of both malnutrition and CVD in ESRD. Thus, it could be speculated that suppression of the vicious cycle of malnutrition, inflammation, and atherosclerosis (MIA syndrome) would improve survival in dialysis patients. As there is not yet any recognized, or even proposed, targeted treatment for ESRD patients with chronic inflammation; it would be of considerable interest to study the long-term effect of various anti-inflammatory treatment strategies on nutritional and cardiovascular status as well as outcome in these patients.

Oral anticoagulant therapy in hemodialysis patients: do the benefits outweigh the risks?

Managing oral anticoagulation may be difficult in hemodialysis patients because the antithrombotic effect can be counterbalanced by an increased risk of hemorrhagic complications. There is insufficient evidence to recommend the routine use of warfarin for thrombosis prophylaxis of the vascular access in all patients. If a decision for anticoagulation is made, dosing warfarin to a "therapeutic" level is suggested, although the most appropriate target INR range remains unclear. Many hemodialysis patients with atrial fibrillation have multiple risk factors for stroke and generally benefit from warfarin, with careful and frequent laboratory monitoring. Treatment with standard dose warfarin is also recommended in patients with venous thromboembolism provided that patients do not have contraindications to anticoagulation. For those with such contraindications, placement of an inferior vena cava filter is suggested. These recommendations are limited by the almost complete lack of data in dialysis patients. Sound randomized evidence of efficacy and harm for anticoagulation in these patients will likely never be available. Knowledge of the risk of bleeding and thrombosis in anticoagulated and nonanticoagulated dialysis patients could be provided by feasible, well-designed cohort studies.

Selective two-stage basilic and cephalic vein transpositions can significantly improve the rate of fistula construction

INTRODUCTION

Modified proximal radial artery arteriovenous fistula (MPRAVF) can be used to improve the success and patency of basilic vein transposition (BVT) and cephalic vein transposition (CVT). In the present study, surgical experience with patients requiring a two-stage BVT or CVT using MPRAVF as the first stage was reviewed.

METHODS

All two-stage BVTs and CVTs performed between September 2004 and October 2006 were retrospectively reviewed. The median follow-up for this cohort was 23.7 months. One-year secondary patency of all transpositions was assessed.

RESULTS

Two hundred nineteen MPRAVFs were constructed. Twelve MPRAVFs failed and underwent a second procedure. Ninety-eight patients required no further procedures and their upper arm cephalic vein was matured and used for dialysis. Of 121 patients whose MPRAVFs were functioning but unusable due to their depth, 87 underwent BVT and 34 underwent CVT. The Kaplan-Meier one-year secondary patencies (± standard error) for BVTs and CVTs were 0.90±0.03 and 0.82±0.06, respectively. At one year, 87% of all transpositions remained patent.

CONCLUSIONS

Use of MPRAVF as the first stage of a two-stage BVT or CVT can significantly improve the patency rate of autogenous hemodialysis access placement beyond the 66% set forth by the Fistula First guidelines.

Role of Vascular Access as a Risk Factor for Infections in Hemodialysis

Infections are a major cause of morbidity and mortality in chronic hemodialysis patients. This single center prospective study was carried out to determine the incidence and risk factors for infection in hemodialysis patients and plan appropriate strategies to reduce the risk of infection. A total of 84 consecutive patients who were initiated on hemodialysis over a 2-year period were followed until they either received a kidney transplant or died. In our hospital, as a policy, patients are offered hemodialysis as a bridge therapy to a kidney transplant. The mean duration of follow up was 3 months (range 1-11.8 months). The factors associated with at least one episode of infection were evaluated. Statistical analysis was done by multivariate stepwise logistic regression method. Fifty-one patients had a total of 57 episodes (67.8%) of infection. Of the 44 episodes of acute bacterial infections, vascular access exit site infection was the commonest followed by septicemia (13 patients, 29.5%). Staphylococcus aureus was the commonest bacterial isolate observed in 14 patients. On multivariate analysis, three risk factors for infection were identified: (1) nonarteriovenous fistula (AVF) vascular access for hemodialysis (p = 0.02), (2) increased number of hemodialysis sessions (p = 0.03), and (3) lower serum calcium level (p = 0.02). NonAVF vascular access was found to be the most important risk factor for infection in hemodialysis patients. Creation of an AV fistula, preferably at an early stage, appears beneficial for minimizing the risk of infection even in patients who are on short-term hemodialysis as a bridge therapy towards a kidney transplant.

Extrapulmonary Tuberculosis in Chronic Hemodialysis Patients

BACKGROUND

The incidence of extrapulmonary tuberculosis is higher in dialysis than general population. The aim of the study was to characterize clinical picture in dialysis patients, who developed extrapulmonary tuberculosis.

METHODS

We retrospectively investigated the hemodialysis patients with extrapulmonary tuberculosis. 2208 hemodialysis patients were reviewed for extrapulmonary tuberculosis from October 1986 to January 2001.

RESULTS

Seventeen patients (10 male, 7 female) were enrolled. The mean age was 57.4 +/- 12.4 years. The sites for extrapulmonary tuberculosis were peritoneum (35.3%, 6/17), cervical lymph node (17.6%. 3/17), bone marrow (5.9%, 1/17), spine (5.9%, 1/17), knee (5.9%, 1/17), brain (5.9%, 1/17), pericardium (5.9%, 1/17), cutaneous tissue (5.9%, 1/17) and genitourinary system (5.9%, 1/17). Fourteen of 15 tissue-biopsy specimens from suspicious sites revealed granulomatous inflammation. There were low yield in mycobacteria culture (11.1%, 1/9) and PCR (33.3%, 2/6). Three patients died during the treatment of the disease.

CONCLUSION

Extrapulmonary tuberculosis constitutes a major part of tuberculosis in dialysis patients. Tissue biopsy with invasive procedures, such as laparoscopy or laparotomy, may be necessary if clinical presentations are suspicious.

Prosthetic arteriovenous grafts for hemodialysis

INTRODUCTION

Prosthetic arteriovenous (AV) grafts are indicated in patients with failed AV fistula (AVF), exhausted superficial veins or unsuitable vessels. Increasing the proportion of prevalent hemodialysis (HD) patients using autogenous AVF should reduce the need for AV grafts and associated morbidity. This paper reviews the current role of prosthetic AV grafts in vascular access for HD.

TECHNICAL CONSIDERATIONS

Prior to the insertion of a prosthetic AV graft, a comprehensive review of previous access procedures and full physical examination in addition to vessel mapping is required. Anastomotic technique should take into account the flow diffuser concept, graft geometry and an anastomotic angle of 15 degrees in order to reduce the incidence of intimal hyperplasia.

RESULTS

Many authors report 1 and 2-yr cumulative graft patency rates of 59-90% and 50-82%, respectively. The major drawbacks with synthetic grafts include: thrombosis, a five-fold increase in infection risk and steal syndrome. The choice between surgical and percutaneous methods of dealing with blocked AV grafts remains controversial, though percutaneous techniques are assuming an increasingly important role. Percutaneous strategies are successful in declotting access in 67-95% of cases. Stenting of stenotic lesions following thrombectomy improves secondary patency rates. Strategies for dealing with AV graft infection include antibiotic prophylaxis, partial, subtotal or total graft excision and the use of biological prosthesis.

CONCLUSIONS

Though more prone to complications than autogenous AVFs, AV grafts offer a short maturation period and are more amenable to thrombectomy by radiological or surgical means. Complex AV grafts may be appropriate in patients with exhausted access sites.

Significant correlation between ankle-brachial index and vascular access failure in hemodialysis patients

BACKGROUND AND OBJECTIVES

Vascular access failure (VAF) is associated with increased morbidity and mortality in hemodialysis patients. The most common cause of VAF is stenosis at the arteriovenous anastomosis because of abnormal neointimal proliferation and extracellular matrix deposition. These two changes are also observed in the classic atheroma, which means atherosclerotic lesions and venous stenosis in VAF may share some similar pathogenic mechanisms. The ankle-brachial index (ABI) is a reliable marker for atherosclerosis. The aim of this study was to evaluate the relationship between ABI <0.9 and VAF.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

All routine hemodialysis patients in one regional hospital were included except for six patients refusing ABI examinations and four patients with atrial fibrillation. Finally, 225 patients formed our study group. The study subjects were observed from arteriovenous access creation until the first episode of VAF. The mean observation period was 42.2 +/- 42.8 mo. The relative VAF risk was analyzed by Cox-regression methods with adjustments for demographic and comorbid conditions.

RESULTS

VAF episodes were recorded in 111 patients. In multivariate analysis, ABI <0.9 (hazard ratio, 1.893; P = 0.039), vascular access type of arteriovenous graft (P = 0.004), and serum triglyceride level (P = 0.043) were positively associated with VAF, and serum parathyroid hormone level (P = 0.043) was negatively associated with VAF.

CONCLUSIONS

Our findings show that ABI <0.9 is significantly correlated with increased VAF. Screening hemodialysis patients by means of ABI may help to identify a high-risk group for VAF.

Nutritional status evaluation and survival in haemodialysis patients in one centre from Romania

BACKGROUND

Protein-energy wasting is a common complication and an important predictive factor for mortality in chronic dialysis patients. Therefore, nutritional status needs to be regularly assessed in these patients, by using several methods, and, if malnutrition is present, its possible causes should be thoroughly searched for and properly treated.

MATERIAL AND METHODS

In 149 prevalent haemodialysis patients (82 men, mean age 53.9 +/- 13.7 years), we evaluated the nutritional status by anthropometrics [post-dialysis height (H), body weight (BW), body mass index (BMI), mid-arm circumference (MAC), tricipital skin-fold thickness (TST), mid-arm muscle circumference (MAMC), corrected mid-arm muscle area (cMAMA) and three-category subjective global assessment score (SGA)], biochemical tests [protein equivalent of nitrogen appearance (nPNA), and pre-dialysis serum albumin, creatinine, total cholesterol, bicarbonate and haemoglobin (Hb) levels] and bioelectrical impedance analysis (BIA) to estimate body composition [percent body fat (%BF), fat-free mass (%FFM), body cell mass (%BCM), extracellular mass (%ECM) and the phase angle (PhA)].

RESULTS

Age was found to be positively correlated with BMI (P = 0.001), and inversely correlated with %BCM (P = 0.013). Patients with A-category SGA were significantly younger (50.1 versus 63.7 years) than those with B-category SGA. Patients with diabetes had lower %BCM (32.9 versus 35.9%; P = 0.035) and PhA (5.5 versus 6.9 degrees ; P = 0.0007) than those without diabetes. The presence of heart failure was associated with significantly reduced nPNA (1.17 versus 1.34 g/kg day; P = 0.014), MAMC (22.0 versus 23.6 cm(2); P = 0.041), %BCM (33.0 versus 36.1; P = 0.021), PhA (5.8 versus 7.0 degrees ; P = 0.031), serum albumin (39.7 versus 42.4 g/l; P = 0.013) and serum creatinine (8.1 versus 9.4 mg/dl; P = 0.010), and with a higher percent of B-category SGA (47.8% versus 22.6%; P = 0.019). Eleven deaths (7.4%) occurred during the follow-up period. Among general factors, age >or= 55, the presence of diabetes, and dialysis vintage <2 years were associated with significantly reduced survival. Among nutritional factors, B-category SGA, nPNA <1.2 g/kg day, %BF <15% and PhA <6 degrees significantly predicted mortality in both Kaplan-Meier and Cox analyses. The most important risk factor appeared to be nPNA; for every 0.1 g/kg day increase in nPNA, death risk decreased by 15%.

CONCLUSIONS

In our haemodialysis patients, advancing age, diabetes and heart failure were associated with worse nutritional status, as estimated by anthropometry, biochemical markers and BIA. Age >or=55 years, the presence of diabetes, nPNA <1.2 g/kg day, lower SGA score, %BF <15% and PhA <6 degrees were associated with significantly increased death risk.

Status of initiating pattern of hemodialysis: a multi-center study

This study was to evaluate the status of initiating pattern of hemodialysis (HD). Five hundred-three patients in 8 University Hospitals were included. Presentation mode (planned vs. unplanned), and access type (central venous catheters [CVC] vs. permanent access) at initiation of HD were evaluated, and the influence of predialysis care on determining the mode of HD and access type was also assessed. Most patients started unplanned HD (81.9%) and the most common initial access type was CVC (86.3%). The main reason for unplanned HD and high rate of CVC use was patient-related factors such as refusal of permanent access creation and failure to attend scheduled clinic appointments. Predialysis care was performed in 57.9% of patients and only 24.1% of these patients started planned HD and 18.9% used permanent accesses initially. Only a minority of patients initiated planned HD with permanent accesses in spite of predialysis care. To overcome this, efforts to improve the quality of predialysis care are needed.

Nutritional status and the role of diabetes mellitus in hemodialysis patients

This study was aimed to investigate the nutritional status and the role of diabetes mellitus in hemodialysis (HD) patients. Anthropometric, biochemical, and dietary assessments for HD 110 patients (46 males and 64 females) were conducted. Mean body mass index (BMI) was 22.1 kg/m(2) and prevalence of underweight (BMI<18.5 kg/m(2)) was 12%. The hypoalbuminemia (<3.5 g/dl) was found in 15.5% of the subject, and hypocholesterolemia (<150 mg/dl) in 46.4%. About half (50.9%) patients had anemia (hemoglobin: <11.0 g/dL). High prevalence of hyperphosphatemia (66.4%) and hyperkalemia (43.5%) was also observed. More than 60 percent of subjects were below the recommended intake levels of energy (30-35 kcal/kg IBW) and protein (1.2 g/kg IBW). The proportions of subjects taking less than estimated average requirements for calcium, vitamin B(1), vitamin B(2), vitamin C, and folate were more than 50%, whereas, about 20% of the subjects were above the recommended intake of phosphorus and potassium. Diabetes mellitus was the main cause of ESRD (45.5%). The diabetic ESRD patients showed higher BMI and less HD adequacy than nondiabetic patients. Diabetic patients also showed lower HDL-cholesterol levels. Diabetic ESRD patients had less energy from fat and a greater percentage of calories from carbohydrates. In conclusion, active nutrition monitoring is needed to improve the nutritional status of HD patients. A follow-up study is needed to document a causal relation between diabetes and its impact on morbidity and mortality in ESRD patients.

Complications of arteriovenous hemodialysis access: recognition and management

English language citations reporting complications of arteriovenous access for hemodialysis are critically reviewed and discussed. Venous hypertension, arterial steal syndrome, and high-output cardiac failure occur as a result of hemodynamic alterations potentiated by access flow. Uremic and diabetic neuropathies are common but may obfuscate recognition of potentially correctable problems such as compression or ischemic neuropathy. Mechanical complications include pseudoaneurysm, which may develop from a puncture hematoma, degeneration of the wall, or infection. Dysfunctional hemostasis, hemorrhage, noninfectious fluid collections, and access-related infections are, in part, manifestations of the adverse effects of uremia on the function of circulating hematologic elements. Impaired erythropoiesis is successfully managed with hormonal stimulation; perhaps, similar therapies can be devised to reverse platelet and leukocyte dysfunction and reduce bleeding and infectious complications.

Medical adjuvant treatment to increase patency of arteriovenous fistulae and grafts

BACKGROUND

End-stage renal disease (ESRD) patients often require either the formation of an arteriovenous (A-V) fistula or an A-V interposition prosthetic shunt for haemodialysis.

OBJECTIVES

To determine the effects of adjuvant drug treatment on the patency of fistulae and grafts in patients with ESRD who are undergoing haemodialysis by assessing the number of thrombotic episodes.

SEARCH STRATEGY

The Cochrane Peripheral Vascular Diseases Group (PVD) searched their Specialised Register (last searched May 2008) and the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 2).

SELECTION CRITERIA

RCTs of active drug versus placebo in patients with ESRD undergoing haemodialysis via an A-V fistula or prosthetic interposition A-V graft.

DATA COLLECTION AND ANALYSIS

For the update, two review authors (ADS, GO) independently assessed trial quality and ADS, XE, and GO extracted data. Information on adverse events was collected from the trials. The outcome measure analysed was the long-term fistula or graft patency rate.

MAIN RESULTS

The overall results of the meta-analysis (three RCTs) comparing aspirin versus placebo favoured treatment with aspirin (odds ratio (OR) 0.42, 95% confidence interval (CI) 0.20 to 0.86; P = 0.02).The overall result of the meta-analysis ( three RCTs) comparing ticlopidine (a platelet aggregation inhibitor) versus placebo favoured active treatment (OR 0.47, 95% CI 0.26 to 0.85; P = 0.01).The overall result from one trial comparing the effect of dipyridamole versus placebo and dipyridamole plus aspirin versus placebo favoured treatment (OR 0.57, 95% CI 0.13 to 2.51; OR 0.77, CI 0.19 to 3.19, respectively).One trial compared fish oil (4 g/daily) versus placebo with 24 participants, follow-up 12 months. The overall result favoured treatment (OR 0.07, 95% CI 0.01 to 0.49).One trial compared low-dose warfarin with placebo, 107 patients were followed for 37 months but the trial was terminated prematurely due to increased bleeding events in the treatment group. The overall result favoured placebo (OR 1.76, 95% CI 0.78 to 3.99).One trial compared sulfinpyrazone versus placebo. Sixteen patients, follow-up three months, and the overall result favoured treatment (OR 0.14, 95% CI 0.01 to 1.99).Finally, one trial compared clopidogrel (75 mg/once daily) with placebo. Twenty-four patients, follow-up over a three-year period until their first episode of thrombosis. The overall result favoured treatment (OR 0.01, 95% CI 0.00 to 0.15).

AUTHORS' CONCLUSIONS

The meta-analysis confirmed the beneficial effect of anti-platelet treatment as an adjuvant used to increase the patency of A-V fistulae and grafts in the short term.

[Dialin: infection surveillance network for haemodialysis patients. First results]

AIM AND BACKGROUND

To show results of the first year of an infection surveillance network for haemodialysis patients (Dialin). In order to improve the security and quality of care, six haemodialysis centers have organized an infection watching network. The purpose of the network is to compare of the watching results between centers. This comparison includes vascular access infection (VAI), bacteraemia and C viral hepatitis. The heterogeneous pattern has been also taken into account. SURVEY TYPE: Multicenter prospective permanent survey.

POPULATION

Six hundred and sixty-four haemodialyzed chronic patients, followed during one year (2005), in six voluntary haemodialysis centers. This survey has based on 71,688 treatment sessions corresponding to 6257.5 months of haemodialysis (HM).

METHODS

As with the heterogeneity among centers, the acquired infection standardized ratios (observed/expected) (AISR) and 95% confidence interval are computed with Cox model which includes confounding factors found in literature or in the preliminary stage of the survey.

RESULTS

VAI crude rate was 0.47 per 100HM, 0.10 per 1000 native fistulae utilisation days, 0.45 per 1000 days of prosthetic graft utilisation and 0.44 per 1000 days of catheter utilisation. Bacteraemia crude incidence rate was 0.69 per 100HM, 0.02 per 1000 days of native fistulae utilisation, 0.00 per 1000 days of prosthetic graft utilisation and 0.39 per 1000 days of catheter utilisation. No new case of C viral hepatitis was found. Prevalence rate at the beginning of the survey was 5.3% (35 over 664). Two centers had a significantly high AISR for VAI and two centers had a significantly low AISR for VAI. One center had a significantly high AISR for bacteraemia and one center had a significantly low AISR for bacteraemia.

CONCLUSIONS

The first year of Dialin running demonstrates the importance of standardised surveillance method in VAI and bacteraemia surveillance but not for viral hepatitis.

The uraemic toxin phenylacetic acid impairs macrophage function

BACKGROUND

Nitric oxide (NO) is known to be an important mediator of macrophage cytotoxicity. NO in macrophages is generated via the inducible nitric oxide synthases (iNOS). Macrophage dysfunction is an important contributory factor for the increased incidence of infections in uraemia. Recently, we identified phenylacetic acid (PAA) as a novel uraemic toxin in patients on regular haemodialysis. PAA inhibits iNOS expression. In the present study, we investigated the impact of PAA on macrophage function.

METHODS

RAW 264.7 cells were stimulated by LPS/ IFN-gamma in the absence and presence of PAA. iNOS mRNA was determined by real-time PCR, iNOS protein was examined by western blotting and the NO degradation product, nitrite, by Griess assay. Macrophage phagocytosis was assessed by FACS and fluorescence microscopy. Further we quantified the cytotoxicity against intracellular bacteria (Salmonella typhimurium) by a macrophage-killing assay. ELISA and Bioplex protein array system was used for the investigation of iNOS second messenger pathways (NF-kappaB, ERK1/2, JNK and p38MAPK). iNOS mRNA half-lifetime in the presence or absence of PAA was determined by real-time PCR.

RESULTS

PAA significantly inhibits iNOS mRNA induction in RAW 264.7 cells by LPS/IFN-gamma [6 h: LPS/IFN-gamma-stimulation: 100%; LPS/IFN-gamma-stimulation/PAA (1 mM): 68 +/- 7%] at concentrations comparable to those of patients on chronic haemodialysis. iNOS protein expression and nitrite formation in RAW 264.7 cells were significantly inhibited by PAA. iNOS mRNA half-lifetime was not affected by PAA. The phagocytic activity of RAW 264.7 was not significantly affected by PAA, whereas the cytotoxicity against intracellular bacteria was significantly reduced. Analysis of the iNOS signal transduction pathways provided evidence that activation of the mitogen-activated kinases ERK1/2 and JNK is significantly blocked by PAA, whereas activation of p38MAPK is unaffected. The NF-kappaB pathway was not affected by PAA.

CONCLUSIONS

The present findings show that the uraemic toxin PAA has inhibitory effects on macrophage-killing function, which are mediated by inhibitory effects on transcriptional iNOS regulation. iNOS inhibition by PAA might affect immunoregulatory processes and could play a role in aggravation of immunodeficiency of patients with end-stage renal disease.

The effectiveness of renal transplantation as a treatment for recurrent uremic cardiomyopathy

Congestive heart failure is more prevalent in patients with end-stage renal disease than in the general population. Although optimal treatment has yet to be defined, these patients are considered to be at high risk for renal transplantation. The present report of a 27-year-old man describes a full recovery from uremic cardiomyopathy following a renal transplant. Despite the patient developing recurrent cardiac dysfunction following graft failure, a second transplant was successful, which, again, resulted in complete resolution of the cardiomyopathy. Patients with recurrent uremic cardiomyopathy following failed kidney transplantation should be considered for a second kidney transplant.

Do AshSplit haemodialysis catheters provide better flow rates in the long term?

BACKGROUND

Recently, interventional radiologists have adopted an increasingly prominent role in the placement and management of hemodialysis catheters, as well as in the research and development of new and better catheters. The purpose of this study was to evaluate the viability and hemodialysis efficiency of the AshSplit catheter and the Permcath catheter.

METHODS

204 consecutive patients requiring radiological insertion of hemodialysis catheters were followed, retrospectively, over a 42-month period. Both hemodialysis catheters were placed using a combination of ultrasonic and fluoroscopic guidance and tunneled appropriately. Information collected included catheter insertion sites, insertion complications, catheter duration, and final outcome.

RESULTS

Over the study period of two years, 269 catheters were placed into 204 patients with end stage renal failure. Patients received either an AshSplit (101 patients, 127 catheters) or a Permcath (103 patients, 142 catheters). Vascular access route of choice was the right internal jugular vein (67% AshSplit, 71% Permcath). Insertion complications occurred in 18 patients overall (6.6%), with only 1 requiring further intervention (hemopneumothorax). Flow rates averaged 259 mls/min for AshSplits and 248 mls/min for Permcaths (p < 0.001). Follow-up of catheter viability for 42 months yielded a mean AshSplit catheter duration of 246 days (range 6-932) and 239 days (range 1-1,278) for Permcath (p = 0.46). Reasons for catheter failure and elective catheter removal were similar in both groups; however, Permcaths required significantly more thrombolysis than AshSplits, p < 0.001.

CONCLUSION

The AshSplit provides significantly better flow rates and less thrombolysis compared to the Permcath, with similar catheter dwell times.