PubMed Health⌕ Search

Biomedical subjects

Anatole Besarab

Publications and source records attributed to Anatole Besarab.

At least 19 recordsLinked to original sources
PubMed2006

A randomized controlled trial of oral versus intravenous iron in chronic kidney disease.

BACKGROUND: It is unknown whether intravenous iron or oral iron repletion alone can correct anemia associated with chronic kidney disease (CKD). We conducted a randomized multicenter controlled trial in adult anemic, iron-deficient non-dialysis CKD (ND-CKD) patients (>or=stage 3) not receiving erythropoiesis-stimulating agents (ESAs). METHODS: The participants were randomized to receive either a sodium ferric gluconate complex (intravenous iron) 250 mg i.v. weekly x 4 or ferrous sulfate (oral iron) 325 mg t.i.d. x 42 days. Hemoglobin (Hgb), ferritin and transferrin saturation (TSAT) were measured serially, and the Kidney Disease Quality of Life (KDQoL) questionnaire was administered on days 1 and 43. The primary outcome variable was change from baseline (CFB) to endpoint in Hgb values. RESULTS: Seventy-five patients were analyzed (intravenous iron n = 36, oral iron n = 39). CFB in Hgb was similar in the two groups (intravenous iron 0.4 g/dl vs. oral iron 0.2 g/dl, p = n.s.). However, the increase in Hgb was only significant with intravenous iron (p < 0.01). In comparison to oral iron, intravenous iron achieved greater improvements in ferritin (232.0 +/- 160.8 vs. 55.9 +/- 236.2 ng/ml, p < 0.001) and TSAT (8.3 +/- 7.5 vs. 2.9 +/- 8.8%, p = 0.007). Intravenous iron caused greater improvements in KDQoL scores than oral iron (p < 0.05). The most common side effect reported with intravenous iron was hypotension, while constipation was more common with oral iron. CONCLUSIONS: Oral and intravenous iron similarly increase Hgb in anemic iron-depleted ND-CKD patients not receiving ESAs. Although in comparison to oral iron, intravenous iron may result in a more rapid repletion of iron stores and greater improvement in quality of life, it exposes the patients to a greater risk of adverse effects and increases inconvenience and cost.

Administration, Oral↗
PubMed2006

Anemia management in chronic heart failure: lessons learnt from chronic kidney disease.

The importance of anemia in chronic kidney disease (CKD) has become increasingly well recognized over recent years, as have the benefits of treating anemic CKD patients with recombinant human erythropoietin (rHuEPO, epoetin). As well as reducing the need for blood transfusions and the complications associated with renal failure in CKD patients, rHuEPO treatment decreases patient morbidity and mortality, particularly as a result of cardiovascular disease. The strong correlation between anemia, renal failure and cardiac failure is one that has received much attention recently, with each factor recognized to cause the other to worsen in a 'vicious cycle'. Recent studies have concentrated on the possible benefits of anemia treatment in patients with CHF. Currently available data suggest improvements in CHF symptoms, left ventricular ejection fraction (LVEF) and a reduction of hospitalizations associated with anemia correction through epoetin treatment. Available data from CKD patients suggest that anemia management should begin as early as possible, although the optimal target level for individual patients is as yet unclear. In addition to the currently available evidence, additional large, randomized, controlled studies are required to further define the morbidity/mortality benefits of epoetin treatment in CHF patients with anemia.

Anemia↗
PubMed2006

Antimicrobial locks: putting the lock on catheter infections.

Infectious complications resulting from catheter use in the hemodialysis population remain as the significant cause of morbidity and mortality in this patient population. Because conservation of vascular access sites remains a therapeutic mainstay for chronic hemodialysis patients, clinical investigators have evaluated the safety and efficacy of catheter preservation with antimicrobial lock solutions instilled into the lumens of catheters to treat and prevent infectious complications. The recommended treatment of catheter-related bacteremia includes administration of systemic antibiotics with catheter removal. To date, 4 studies in the hemodialysis population have evaluated the use of systemic antibiotics with an antimicrobial lock solution for treatment of catheter-related bacteremias to amplify the success of catheter salvage. The use of antimicrobial lock solutions for the treatment of catheter-related bacteremia has resulted in successful catheter salvage in approximately 69% of patients, with the remainder requiring catheter removal following a lack of clinical improvement after 48 hours. The antimicrobial lock has also been studied as a prophylactic measure to prevent catheter-related bacteremia. Six studies in the hemodialysis population have evaluated the use of an antimicrobial lock for the prevention of catheter-related bacteremia with an overall 64%-100% reduction in the frequency of catheter-related bacteremia. Although the use of antimicrobial lock for prophylaxis has demonstrated efficacy in clinical trials, its long-term consequences, including potential impact on antimicrobial resistance, are unknown. The objectives of this review are to evaluate the current body of evidence espousing the utilization of an antimicrobial lock solution in tunneled cuffed and uncuffed catheters that are utilized during chronic intermittent hemodialysis.

Anti-Bacterial Agents↗
PubMed2006

Effect of intravenous ascorbic acid in hemodialysis patients with EPO-hyporesponsive anemia and hyperferritinemia.

BACKGROUND: Although erythropoietin (EPO)-hyporesponsive anemia in hemodialysis patients most commonly results from iron deficiency, the contributory role of chronic inflammation and oxidative stress in its pathogenesis is poorly understood. We conducted an open-label prospective study to assess the effect of vitamin C, an antioxidant, on EPO-hyporesponsive anemia in hemodialysis patients with unexplained hyperferritinemia. METHODS: Forty-six of 262 patients in an inner-city hemodialysis center met the inclusion criteria (administration of intravenous iron and EPO for > or = 6 months at a dose > or = 450 U/kg/wk, average 3-month hemoglobin [Hb] level < or = 11.0 g/dL [< or = 110 g/L], ferritin level > or = 500 ng/mL (microg/L), and transferrin saturation [TSAT] < or = 50%). Patients were excluded if they had a clear explanation for the EPO hyporesponsiveness. Four patients refused to participate. The remaining patients were randomly assigned; 20 patients to receive standard care and 300 mg of intravenous vitamin C with each dialysis session (group 1) and 22 patients to receive standard care only (group 2). Study duration was 6 months. During the study, 1 patient from group 1 was removed (upper gastrointestinal bleeding) from final analysis. Monthly assessment included Hb level, mean corpuscular volume, iron level, iron-binding capacity, ferritin level, TSAT, and Hb content in reticulocytes. In addition, biointact parathyroid hormone, aluminum, C-reactive protein (CRP), and liver enzymes were measured every 3 months. RESULTS: Age, sex, race, and time on dialysis therapy were similar in both groups. At 6 months, Hb levels significantly increased from 9.3 to 10.5 g/dL (93.0 to 105.0 g/L) in group 1, but not group 2 (9.3 to 9.6 g/dL [93.0 to 96.0 g/L]; P = 0.0001). Similarly, TSAT increased from 28.9% to 37.3% in group 1, but not group 2 (28.7% to 29.3%; P = 0.0001). EPO dose (477 to 429 versus 474 to 447 U/kg/wk), iron-binding capacity (216 to 194 versus 218 to 257 microg/dL [38.7 to 34.7 versus 39 to 46 micromol/L]), and CRP level (2.8 to 0.9 versus 2.8 to 2.2 mg/dL) decreased significantly in group 1, but not in controls. Changes in Hb content in reticulocytes and ferritin level also were statistically significant in group 1. There was no change in biointact parathyroid hormone levels. Although serum iron levels and intravenous iron doses changed within each group, changes were equal between the 2 groups. CONCLUSION: In hemodialysis patients with refractory anemia and hyperferritinemia, vitamin C improved responsiveness to EPO, either by augmenting iron mobilization from its tissue stores or through antioxidant effects.

Adult↗
PubMed2006

Comparison of low-dose gentamicin with minocycline as catheter lock solutions in the prevention of catheter-related bacteremia.

BACKGROUND: Catheter-restricted antibiotic lock solutions were found to be effective in the prevention of catheter-related bacteremia (CRB), but insufficient data are available about the ideal agent and dose. We hypothesized that a low concentration of gentamicin would be as effective as the high doses studied in the past. METHODS: In this prospective, open-labeled, randomized, clinical trial of patients on long-term hemodialysis therapy, patients were randomly assigned to administration of an antibiotic lock solution of gentamicin/citrate (4 mg/mL), minocycline/EDTA, or the control solution of heparin. Patients were followed up until the study end point of CRB was reached or a censoring event occurred. Interim data analysis was performed after 6 months to assess data safety; efficacy was noted and the study was terminated early. RESULTS: Sixty-two patients were enrolled into the study, evenly distributed in 3 arms, with data from 1 patient excluded from analysis. Seven of 20 patients in the heparin group (4.0 events/1,000 catheter days), 1 of 21 patients in the minocycline group (0.4 events/1,000 catheter days), and none of 20 patients in the gentamicin group developed bacteremia. Results were statistically significant by using 2-tailed Fisher exact test; heparin versus gentamicin, P = 0.008, and heparin versus minocycline, P = 0.020. CONCLUSION: Antibiotic lock solutions are superior to the standard heparin lock alone in the prevention of CRBs, and low-dose gentamicin solution has efficacy similar to that of greater concentrations used in previous studies.

Anti-Bacterial Agents↗
PubMed2006

Access monitoring is worthwhile and valuable.

During the past several years, a limited number of small clinical trials have questioned the role of surveillance in the management of vascular accesses, since the prolongation of access longevity until replacement was not altered. Although prolongation of access life span is an important endpoint, it is not the only one. Reduction in thrombotic events reduces the risks to the patient resulting from loss of access patency. The body of evidence suggests that the detection of stenosis and prevention of thrombosis are valuable. When a test indicates the likely presence of a stenosis, venography or fistulography should be used to definitely establish the presence and the degree of the stenosis. In most cases, angioplasty should be performed if the stenosis is greater than 50% by diameter. The value of routine use of any surveillance technique for detecting anatomic stenosis alone without concomitant functional assessment by measurement of access flow, venous pressure, recirculation, or other physiologic parameter has not been established. Stenotic lesions should not be repaired merely because they are present. If such correction is performed, then intra-procedural studies of access flow or intra-access pressure prior to and following percutaneous transluminal angioplasty should be conducted to demonstrate a functional improvement with a 'successful' percutaneous transluminal angioplasty.

Catheters, Indwelling↗
PubMed2005

Optimizing anaemia management with subcutaneous administration of epoetin.

European and US guidelines for renal anaemia management recommend subcutaneous (s.c.) epoetin as the preferred route of administration in pre-dialysis, peritoneal dialysis and haemodialysis patients. However, the restriction of Eprex/Erypro to intravenous (i.v.) administration in Europe has increased the interest of health care professionals regarding the optimal route of administration for all epoetin formulations. There are five major considerations for the 'optimal' route of epoetin administration: efficacy; dosing frequency; convenience; safety and tolerability; and cost. Although epoetin bioavailability is lower after s.c. administration, its efficacy is higher, owing to its prolonged elimination half-life compared with i.v. epoetin. Several studies and clinical surveys comparing s.c. and i.v. administration have demonstrated that equivalent target haemoglobin levels can be maintained at much lower doses of epoetin when administered s.c. Furthermore, s.c. epoetin dosing frequency can be reduced in some patients to once every 2 weeks, without compromising efficacy. Devices such as the Reco-Pen have been specifically designed to facilitate self-administration of s.c. epoetin-beta. An upsurge in the incidence of pure red cell aplasia (PRCA) was linked to the epoetin-alpha product Eprex/Erypo in Europe, and an increase in PRCA cases of the same magnitude was not seen in patients taking other epoetin products s.c. Therefore, PRCA should not be used as an argument against s.c. administration. The reduced dose with s.c. administration of epoetin-beta provides significant cost benefits, without compromising either safety or efficacy, and may also increase patient satisfaction and compliance with treatment.

Anemia↗
PubMed2004

Vascular access results from the Dialysis Outcomes and Practice Patterns Study (DOPPS): performance against Kidney Disease Outcomes Quality Initiative (K/DOQI) Clinical Practice Guidelines.

BACKGROUND: The Kidney Disease Outcomes Quality Initiative Guidelines for Vascular Access in hemodialysis patients recommend native arteriovenous (AV) fistulae over AV grafts or catheters for permanent vascular access. They recommend letting fistulae mature > or =1 month before cannulation. METHODS: The Dialysis Outcomes and Practice Patterns Study (DOPPS) provides an unparalleled means to examine vascular access practice patterns and guidelines internationally, with particular attention to associations with mortality risk. RESULTS: Most patients in Europe and Japan dialyze through AV fistulae and very few use AV grafts; in the United States, more patients use grafts than fistulae. Patients who receive nephrologic care for over 30 days before starting dialysis have significantly higher chances of commencing via AV fistula. Medical directors of dialysis facilities in the United States commonly prefer grafts; in Europe and Japan, most prefer fistulae. In the United States, there is a relatively long average time between fistula creation and cannulation but significantly worse fistula survival than that seen in Europe. Tunneled catheters pose a higher mortality risk than permanent accesses and are associated with increased risk of failure of a subsequent fistula. The percentage of prevalent patients in the DOPPS countries using catheters has increased in recent years. DOPPS data suggest that performance in some countries falls short of practices achieved in other countries. AV fistula use is low in the United States but has been improving. The trend of increasing use of catheters in most countries is discouraging. CONCLUSION: The DOPPS will continue to monitor practice trends and explore whether greater application of guidelines will lead to fewer access complications and improved longevity for hemodialysis patients.

Arteriovenous Shunt, Surgical↗
PubMed2004

Vascular access for hemodialysis: 2004 and beyond.

PURPOSE OF REVIEW: Developments in vascular access are accruing rapidly. The last systematic Kidney Disease Outcomes Quality Initiative guidelines review took place in 2000. The purpose of this review is to update several major areas in which clear progress has been made. A major 'Fistula First Initiative' in the USA is an attempt to increase markedly the fraction of patients receiving an autologous arteriovenous fistula as opposed to a graft. Preoperative mapping to evaluate veins and artery may permit construction of arteriovenous fistula in up to 70% of all patients, thereby reducing access thrombosis, infection, and perhaps increasing survival of patients. RECENT FINDINGS: Although a number of different synthetic materials have been tried, none seems to have any definite advantage over plain expanded polytetrafluoroethylene for constructing synthetic bridge grafts. Two developments may influence practice: use of composite self-sealing grafts that can be used within hours may eliminate the need for temporary catheters; and use of nitinol surgical clips may reduce endothelial trauma and improve patency. Large-bore catheters can deliver blood flows of over 400 ml/min initially, but they are prone to progressive occlusion. Optimal means of using a fibrinolytic to preserve flow must be evaluated. Surveillance techniques are undergoing rapid re-evaluation. Finally, a variety of antibiotic lock techniques are being evaluated for their ability to prevent catheter-related infections. SUMMARY: Greater efforts must be made to establish pre-end-stage renal disease programs to educate and prepare patients for hemodialysis and improve arteriovenous fistula placement rates, and to encourage clinicians to re-examine their current clinical practices and dedicate themselves to improving vascular access outcomes.

Arteriovenous Shunt, Surgical↗
PubMed2004

Effect of differing blood lines on delivered blood flow during hemodialysis.

UNLABELLED: BACKGROUND The influence of differing blood tubing sets on delivered dialyzer blood flow (Q B ) was studied using ReadySet (RS; Medisystem Inc, Seattle, WA) and CombiSet (CS; Fresenius, Walnut Creek, CA). METHODS: In vitro, we measured Q B and pre-pump arterial pressures (P A; in millimeters of mercury) during 4 hours at a prescribed blood pump flow (Q P ) of 450 mL/min, using a glycerin-water mixture for RS and CS blood tubing sets (n = 10 each). We then performed 3 clinical studies to determine the difference between Q P and Q B as a function of P A for both tubing types and any effects of tubing type on delivered Kt/V in patients. RESULTS: In vitro, 4-hour time-averaged Q B was 451 mL/min with RS versus 422 mL/min with CS. Q B was approximately 40 mL/min greater using RS than CS blood tubing sets at Q P of approximately 445 mL/min with [Q P - Q B ] increasing linearly with P A for CS, but not RS (study 1). At a mean Q P of approximately 408 mL/min, CS blood tubing significantly increased Kt/V by approximately 0.1 (90 patients; study 2). In study 3, [Q P - Q B ] increased with treatment time with CS (8 to 29 mL/min), but not RS (from -4 to 6 mL/min). For patients achieving equal Q P of 400 mL/min or greater for all treatments (n = 11), paired analysis showed greater values for urea reduction ratio (+3.5%; P = 0.039) and Kt/V (+0.14; P = 0.04) with RS than CS tubing sets. CONCLUSION: Differences in [Q P - Q B ] occur both in vitro and in vivo, are much smaller with RS than CS tubing sets, and result in a greater delivered Kt/V of up to 0.14 for RS.

Blood Flow Velocity↗
PubMed2003

Regional variability in anaemia management and haemoglobin in the US.

BACKGROUND: Regional differences in haemoglobin values and process care measures were examined using data from the Centers for Medicare & Medicaid Services' End-Stage Renal Disease (ESRD) Clinical Performance Measures Project. It was posited that regional differences in haemoglobin values are consequent upon differences in components of clinical practice. METHODS: A national random sample of 8336 adult, in-centre haemodialysis patients, stratified by the 18 regional ESRD Networks, was drawn. Information was collected for October-December 1998. Multivariable stepwise linear and logistic regression analyses were performed to identify variables associated with haemoglobin. Linear regression analysis was used to identify variables associated with Epo/Hb index (mean weight-adjusted treatment level erythropoietin (Epo) dose divided by mean haemoglobin). RESULTS: The percentage of patients with haemoglobin concentration < 11 g/dl ranged from 34 to 52% across ESRD Networks. In addition to haemoglobin there was significant, non-random variation among ESRD Networks with regard to prescribed Epo dose and administration route, intravenous (IV) iron prescription and dialyser flux (high flux = KUf > or = 20 ml/mmHg/h) (all P-values < 0.001). Higher haemoglobin was associated with older age, male gender, higher serum albumin, higher transferrin saturation, higher Kt/V, lower serum ferritin and lower prescribed Epo dose (all P-values < 0.01). Diabetes mellitus as cause of ESRD, high-flux dialyser use, IV iron prescription or subcutaneous Epo prescription were not associated with haemoglobin. Male gender, diabetes as cause of ESRD, older age, higher transferrin saturation and higher albumin concentrations were associated with lower Epo/Hb index. Prescription of IV iron and IV Epo were associated with higher Epo/Hb index. CONCLUSIONS: Regional mean haemoglobin levels vary considerably across the US and the variation in haemoglobin is explained by both non-modifiable factors and modifiable clinical practice-derived variables.

Adult↗
PubMed2002

Meta-analysis of subcutaneous versus intravenous epoetin in maintenance treatment of anemia in hemodialysis patients.

BACKGROUND: Clinical and pharmacokinetic studies have shown that target hemoglobin or hematocrit levels can be maintained using a reduced recombinant human erythropoietin (epoetin) dosage by switching from intravenous (IV) to subcutaneous (SC) administration. METHODS: We conducted a meta-analysis of comparative studies of epoetin administered IV versus SC to assess the relative costs of these administration routes. Twenty-seven prospective clinical studies involving 916 patients were included in the analysis. The average difference between IV and SC doses of epoetin and average difference in drug costs between administration routes were determined. RESULTS: The average reduction in dose in patients treated with SC versus IV epoetin was 48 IU/kg/wk (P < 0.001), representing an average annual cost savings with SC administration of US $1,761 +/- $1,080 (SD) per patient. The difference between SC and IV doses was similar in both parallel- and crossover-design studies. A retrospective US survey showed a dose reduction of 26 IU/kg/wk (P < 0.001) with SC administration, translating to an annual savings of $946 per patient. CONCLUSION: This study indicates that the cost of epoetin is reduced substantially when administered SC in comparison to IV. Recommendations of current US and European guidelines, which encourage the use of SC administration, not only have a sound rationale in terms of efficacy and safety, but also have a sound economic basis.

Anemia↗
PubMed2002

Dynamic venous access pressure ratio test for hemodialysis access monitoring.

BACKGROUND: Early recognition of arteriovenous graft (AVG) dysfunction in hemodialysis (HD) patients followed by prompt corrective procedures reduces AVG thrombosis rates and lengthens access survival. We developed a method to prospectively monitor AVGs that uses an algorithm to calculate venous access pressure (VAP) during HD from the venous drip chamber pressure (VDP). METHODS: Sham HD with blood was performed using standard blood tubing and a 1-in. 15-G needle. The pressure needed to overcome circuit resistance at an intra-access pressure of zero (VDP(0)) was recorded at blood flow rates (Q(b)s) from 0 to 600 mL/min and hematocrits varied in steps from 38.4% to 18.2%. An equation for VDP(0) was developed. VAP in patients was calculated as VAP = VDP - VDP(0). VAP ratio (VAPR) was defined as VAP/mean arterial pressure (MAP). VAPR was calculated only if MAP was greater than 75 mm Hg, Q(b) was greater than 200 mL/min, and VDP was greater than 20 mm Hg. A positive VAPR test (VAPRT) result was defined as three consecutive treatments with VAPR exceeding 0.55 during a given month. Sensitivity and specificity of VAPRT to predict a graft event, defined by AVG occlusion or requirement for angioplasty, were calculated. RESULTS: During a 3-month interval, 120 HD patients with AVGs underwent 359 VAPRTs while access outcomes were monitored for 6 months. After 3 months, sensitivity and specificity for detection of a graft event were 70% +/- 8% and 88% +/- 2% and increased to 74% +/- 5% and 92% +/- 3% at 6 months, respectively. CONCLUSION: The VAPRT is a valuable tool to prospectively monitor for adverse AVG events.

Algorithms↗
PubMed2002

Iron sucrose: the oldest iron therapy becomes new.

Several parenteral iron preparations are now available. This article focuses on iron sucrose, a hematinic, used more widely than any other for more than five decades, chiefly in Europe and now available in North America. Iron sucrose has an average molecular weight of 34 to 60 kd, and after intravenous (IV) administration, it distributes into a volume equal to that of plasma, with a terminal half-life of 5 to 6 hours. Transferrin and ferritin levels can be measured reliably 48 hours after IV administration of this agent. Iron sucrose carries no "black-box" warning, and a test dose is not required before it is administered. Doses of 100 mg can be administered over several minutes, and larger doses up to 300 mg can be administered within 60 minutes. The efficacy of iron sucrose has been shown in patients with chronic kidney disease (CKD) both before and after the initiation of dialysis therapy. Iron sucrose, like iron gluconate, has been associated with a markedly lower incidence of life-threatening anaphylactoid reactions and may be administered safely to those with previously documented intolerance to iron dextran or iron gluconate. Nonanaphylactoid reactions, including non-life-threatening hypotension, nausea, and exanthema, also are extremely uncommon with iron sucrose. Management of patients with the anemia of CKD mandates that we carefully examine the effectiveness and safety of this oldest of iron preparations and the accumulating present-day data regarding it and contemporaneous agents.

Chronic Disease↗
PubMed2002

Recommended standards for reports dealing with arteriovenous hemodialysis accesses.

The incidence rate of treated end-stage renal disease in the united states is 180 per million and continues to rise at a rate of 7.8% per year. Arteriovenous hemodialysis access (AV access) creation and maintenance are two of the most difficult issues associated with the management of patients on hemodialysis. The 1-year complication rate of a primary prosthetic AV access for hemodialysis ranges from 33% to 99%. Various investigators report on patency and complications of AV access. However, it is rather difficult to compare outcomes because of the wide variety of access materials, configurations, locations, risk factors, and quality of inflow and outflow vessels. Although there have been reporting standards for dialysis access endovascular interventions and for central venous access placement, standards regarding surgical access placement and its revision are lacking. The "Dialysis Outcome Quality Initiative," published by the National Kidney Foundation, provides recommendations for optimal clinical practices aimed at improving dialysis outcome and patient survival. This reporting standards document is not meant to be a "practice guidelines" or "best practices" document. Rather, the purpose of this document is to provide standardized definitions related to AV access procedures and to recommend reporting standards for patency and complications, to be used by surgeons, nephrologists, and interventional radiologists, that will permit meaningful comparisons among AV access procedures. The terms, definitions, and categories featured in this article have been approved by the Committee on Reporting Standards of the Society for Vascular Surgery and the American Association for Vascular Surgery and should be observed in preparing manuscripts on AV accesses for submission to the Journal Of Vascular Surgery.

Arteriovenous Shunt, Surgical↗