Protecting Restricted Extremities: The Implementation of a Pink Wristband

Nurses should protect the affected extremities of patients who have a permanent arteriovenous access for hemodialysis by avoiding blood pressure measurements and venipuncture on access extremities. National recommendations include labeling the affected extremity with an alert mechanism, such as a wristband, to notify patients and staff of arteriovenous access. A policy change was enacted at an academic medical center in the Southeast to identify restricted extremities with a pink "limb alert" wristband after review of national recommendations on hemodialysis access preservation, individual facility procedures, product cost-benefit analysis, and unit and system educational methods. Keeping simplicity, nursing workload, and flexibility at the forefront of implementation, evaluation, and process revision, an overall adherence rate of 84.2% was achieved three months after implementation of the policy.

Nursing Care for Patients with Synthetic Arteriovenous Grafts

Dealing with a growing older adult patient population, keeping pace with current guidelines, and adhering to new recommendations is a perpetual endeavor for healthcare professionals. Because determining the best access for individual patients is not always obvious, vascular access is a challenging aspect of patient care. This article presents information on the ever-evolving and improving world of vascular access, specifically synthetic grafts.

Moving beyond the "perpetual novice": understanding the experiences of novice hemodialysis nurses and cannulation of the arteriovenous fistula

Cannulation of the arteriovenous fistula (AVF) is an essential skill for hemodialysis (HD) nurses. With declining rates of AVFs, opportunities to develop expert cannulation skills have become limited. This study explored the concept of perpetual novice and AVF cannulation from the perspective of the novice cannulator. Nine hemodialysis nurses were interviewed using ethnographic methodology. The study identified the interplay between personal and environmental/contextual factors that hindered skill acquisition. Personal attributes identified by participants included HD nurses' approach to learning and previous experience, emotional reaction to stress, and interpersonal relationships with colleagues. Environmental/contextual factors identified as impediments to cannulation skill development included limited learning opportunities, attitudes and demands from patients, unit flow and time pressures, and limitations imposed by the current model of nursing care. This study will be helpful in directing future educational, operational, and supportive interventions for novice HD nurses around cannulation skill development.

COMPLICATIONS OF VASCULAR ACCESS: RESULTS OF A EUROPEAN MULTI CENTRE STUDY OF THE EDTNA/ERCA RESEARCH BOARD

The pilot project of the Research Board of EDTNA/ERCA handled the management of vascular accesses (VA) in European dialysis centres. In the first part of the study, centre policies related to VA management were investigated. In the second part of the study, individual patients were followed prospectively during one year. This paper reports on several topics of the second part of the project, investigating complications of the VA related to centre, patient characteristics and dialysis techniques used. Complications most frequently observed were thrombosis, stenosis, infection, bleeding and flow problems. Gradually more infections and flow problems were observed if the centre size and the patients/nurse ratio went up. Complication rate was not significantly influenced by age, gender, renal diagnosis, time on dialysis or medication used by the patient. In contrast, the number of vascular accesses in the past and interventions in the VA before first use resulted in an increased number of complications. Nurses have a key role in the prevention, manipulation and outcome of vascular access related complications.

The ongoing challenges with renal vascular access

Renal vascular access is pivotal in the care of the haemodialysis patient; however, it remains a significant challenge to maintain vascular access in the dialysis population. There are a number of renal vascular accesses in use: arteriovenous fistula, arteriovenous graft, and central venous catheter, with the arteriovenous fistula being the ideal choice. Poor vascular access can lead to serious consequences for patients, resulting in morbidity and even mortality. There are also significant cost implications for healthcare providers in terms of hospital admissions, and other associated costs for patients who are admitted late for vascular access referral or as a result of associated complications of vascular access. The nurse and other members of the healthcare team are fundamental in the management of a patient's renal vascular access.

The culture of vascular access cannulation among nurses in a chronic hemodialysis unit

The native arteriovenous fistula (AVF) is the vascular access of choice for patients on chronic hemodialysis (HD) because of its longevity and lower complication rate. Yet from 2001 to 2004 in Canada, there has been a notable increase in both incident and prevalent central venous catheter (CVC) use with a corresponding decrease in AVF use over the same time period (Moist, Trpeski, Na, & Lok, 2008). A similar trend has been found in other countries (Moist, Chang, Polkinghorne, & McDonald, 2007). There are a number of contributing factors to low AVF use in patients on chronic hemodialysis. While some of these factors may be patient-related, nursing interventions specific to cannulation may be a contributor. To date, little is known about HD nurses' attitudes and experiences regarding cannulation. The purpose of this study was to describe the culture and everyday practices of vascular access cannulation of the AVF from the perspective of the HD nurse. An ethnographic research design was employed, utilizing qualitative methods. Ten HD nurses were interviewed using a semi-structured interview tool, and a number of themes were generated from the interviews. One overarching theme of "perpetual novice" was evident, acknowledging the failure to transition from novice to expert cannulator despite working in HD for a number of years. Other common themes that emerged from the interviews were a) the lack of fistulas, b) the fistula as a "hard sell" to patients, c) the skill of cannulation, and d) the assembly-line approach to care. As a result of a number of factors, HD nurses were unable to acquire the skills necessary to become an expert cannulator. Moreover, the decrease in opportunities to practise cannulation has resulted in wide variation in skill level among HD nurses. To improve cannulation skills and achieve successful cannulation of AV fistulas, HD nurses identified a number of educational strategies that should take place. They also identified the need for an improved documentation system in order to track cannulation-related problems. Results of this study may be helpful in understanding the culture of cannulation in a chronic HD unit and in directing future educational, supportive, and practice interventions for HD nurses.

Impact of single-needle therapy in new chronic hemodialysis starts for individuals with arteriovenous fistulae

The native arteriovenous fistula (AVF) is the "gold standard" for hemodialysis (HD) vascular access. Unfortunately, AVFs can develop complications including inadequate maturation, cannulation difficulties and needle infiltration. In an effort to increase successful cannulations, decrease complications and subsequent central venous catheter (CVC) use, our centre introduced single-needle (SN) dialysis in April 2006 for new chronic patients receiving their first six HD treatments. The purpose of this study was to evaluate the impact of implementing SN dialysis on the incidence of CVC placements, investigative procedures required (e.g., arteriography), and missed HD treatments within the first three months of commencing dialysis. A secondary objective was to compare these data with double-needle (DN) dialysis treatments from the previous year. Retrospective chart reviews were conducted for all new chronic HD outpatient starts from April 2005 to 2006 for patients using DN dialysis and from April 2006 to November 2007 for those using SN. Information gathered included demographic data, location and vintage of the AVF, laboratory parameters, frequency of CVC placements, arteriography, and missed HD treatments due to cannulation difficulties. In total, data pertaining to 11 DN and 22 SN patients were collected. Of the 11 DN patients, 2 (18.2%) required a CVC placement in the first three months of treatment as compared to 2 (9.1%) using SN dialysis. Similarly, arteriographic investigations of the AVF were required in 4 (36.4%) DN versus 3 (13.6%) SN patients. There were a total of 19 missed treatments (8 DN; 11 SN). Dialysis blood work results were within safe and acceptable levels for those receiving SN dialysis. Use of SN dialysis for the first six HD treatments resulted in fewer mean CVC placements and investigations while main-raining adequate laboratory parameters. These results lend support for further research in this area.

[Vascular access surgery--technique and teamwork]

With the growing number of diabetics and patients with multiple problems vascular access surgery increases and therapies become more challenging. If haemodialysis is the therapy of choice for renal failure, veins of the patient's upper limbs should be preserved. Autologic fistula of the upper limb--most commonly between the radial artery and the cephalic vein--is the best option with the lowest complication risks. The purpose of vascular access surgery is to reconstruct and maintain the function of a vascular access, in collaboration with nephrologists and radiologists. To achieve this the nursing and medical personnel should be educated to use dupplex ultrasound in the diagnosis of malfunctioning accesses and needling problems during haemodialysis.

Buttonhole cannulation--an unexpected outcome

The buttonhole method of needle insertion has been reported to be a safe and effective means of cannulation. In general, infections in patients with arteriovenous fistula access are considered to be infrequent compared to other types of accesses. Although minimal data exist regarding infection rates with buttonhole cannulation, these authors' data indicate that the infection rate with buttonhole cannulation may be underestimated.

[Management of vascular access: monitoring and surveillance]

This article reviews vascular access (VA) assessment methods and procedures. It gives an overview of the existing methods for bed-side VA assessment by means of pressures, recirculation and access flow measurement. Pros and cons of the methods are discussed and additional benefits of a combined recirculation and access flow measurement are explained. Present vascular access care guidelines are discussed, namely the K/DOQI and EVAS documents. Practical setup of a vascular access monitoring and surveillance system is illustrated with data from the authors' own unit where such a system has been in use since 1999. The issue of adequate target setting is analysed in view of published works on clinical impact of access surveillance system introduction (timely detection of access stenosis and access patency). Critical re-evaluation is needed especially in current QVA threshold and intervention timing.

[Self-care of arteriovenous fistula by patients with chronic renal failure]

This descriptive study aimed at identifying care of arteriovenous fistula (AVF) performed patients under hemodialysis. Twenty one hemodialysis patients were randomly selected in a clinic in Fortaleza, Ceara, Brazil: 11 female and 11 male patients, age between 30 and 50 year -old, and most were single, retired, and had low education level. Semi-structured interview was applied. The following procedures were mentioned: cleaning the fistula arm, thrill palpation, avoiding lifting weight with AVF arm, arterial pressure checks, taking medication, and blood collection. It was considered that the patients learnt to adapt themselves to the limitations imposed by chronic kidney failure on their lives.

Interventional radiology: new roles for nurse practitioners

Because interventional radiology has become a common adjunct in vascular access care, advanced practice nurses (APNs) have recently been utilized to perform additional duties in the radiology department. This not only frees the radiologist to concentrate on direct patient care and interventional procedures but also allows the APN to coordinate the patients' radiological and dialysis care, provide patient education, and act as a resource to the dialysis facility.

The buttonhole technique for arteriovenous fistula cannulation

The buttonhole technique began 30 years ago in Europe and Japan, and 25 years ago in Seattle, Washington. Some believe its failure to "catch on" in the United States is due to the graft culture of the last 20 years. Now with an increase of AV fustulae, this technique is becoming known as a viable cannulation option. The purpose of this article is to provide technical information for nephrology nurses performing this technique.

[Prospective monitoring of vascular access in hemodialysis by means of a multidisciplinary team]

PURPOSE

Nowadays, expert guidelines recommend the monitoring programs of the vascular access (VA) by a multidisciplinary team.

MATERIAL AND METHOD

We present the experience over the last five years, of a prospective VA surveillance by a multidisciplinary team. The quality indicators reached are described as the associated factors for survival of the new VA.

RESULTS

Three hundred seventeen VA have been studied, 73% were arteriovenous fistulas(AVF) and the rest were polytetrafluoroethylene (PTFE) grafts at 282 patients. The main causes of dysfunctions were elevated dynamic venous pressure (42.5%) and the decreased blood flow (36.4%) with a 88% of positive predictive value. Over the 5 years there was 88 thrombosis (24 AVF and 64 PTFE grafts), that means a hazard thrombosis global rate of 0.15 access/year, which were distributed in 0.06 for AVF and 0.38 in PTFE grafts. Two hundred and one repairs of VA were done: 66.6% were elective repair after a proper review by the multidisciplinary team and the rest of them were done after the AV thrombosis happened. Urgent rescue surgeries were done in 76% of the thrombosis. 62.5% of the patients did not need a catheter after vascular access thrombosis. The complication relation with AVF and PTFE were 11.4% of the total patients hemodialysis hospitalizations. 65.2% of the VA were new access. 57% of patients were properly reviewed in the pre-dialysis unit at least once and 80% of them start haemodialysis with a mature access. The average survival (Kaplan Meier) of the new AVF was 1,575+/-55 days vs 1,087+/-102 of the PTFE grafts (p < 0.008). The survival after 1, 2 and 3 years for the AVF was 89%, 85% and 83% and for the PTFE graft 3% 67% and 51% respectively. The Cox regression has proved that the type of vascular access is the strongest factor associated to VA survival. The survival added of VA repaired due to dysfunction was 1,062 +/- 97 days vs 707 +/- 132 due to thrombosis, log rank 5.17 (p < 0,02). The increasing risk of those repaired after a thrombosis vs dysfunction is 4.2 p < 0,01.

CONCLUSIONS

The monitoring of the vascular access by a multidisciplinary team has reached:low rate of thrombosis, high elective number of repairs of the VA, high urgent rescue surgery after a thrombosis and a few number catheter needed and hospitalizations. AVF are associated with greater survival than PTFE. The VA repair due to dysfunction vs thrombosis had a greater survival as well.

Nurses' impact on the choice and longevity of vascular access

A preponderance of data highlights significant improvements in outcomes when patients dialyze with arteriovenous fistulae compared with either catheters or grafts. "Fistula First" is a nationwide, evidence-based, quality improvement effort that is striving to improve vascular access outcomes by increasing the percentage of patients who dialyze with arteriovenous fistulae. Nephrology nurses will have a profound effect on achieving the goals outlined by Fistula First, including both the choice and longevity of vascular accesses.

The vascular access coordinator role: an interview with Donna Carlton by Betsy King

In summary, the access coordinator is at the center of our access program at UAB. The coordinators can make decisions based on the calls we receive from the nursing staff and reports obtained from procedures. The ability to relay information to the entire team rather than simply data entry staff, makes us a central focal area for our access team. This type of model is working to help us achieve better patient outcomes. We provide many services but the most important is follow-up. As a result, we are able to achieve optimal outcomes for our patients.

Improving arteriovenous fistula cannulation skills

Cannulation of arteriovenous fistulae is technically more challenging than cannulation of arteriovenous grafts. With the advent of the National Vascular Improvement Initiative, Fistula First, the United States has seen an increase in the number of arteriovenous fistulae. The problem we now face is how to refocus and reeducate nurses to the intricacies of arteriovenous fistula cannulation. Through evidenced-based practice and current best-demonstrated practices, this article will provide the tools needed to improve arteriovenous fistulae cannulation skills.

Simple pressure measurement is not reliable in detection of access stenosis in native AV fistulas

Dynamic arterial and venous pressures (PA, PV) are used as the simplest tools to assess vascular access quality (VAQ). An increased PV over three consecutive dialyses is believed to indicate a stenosis, a rule devised for synthetic grafts (AVG) but not adequately validated for AV fistulas (AVF). In this study dynamic PV and static intra-access pressure (calculated by means of the simplified formula PIA=(PA+PV)/2) changes were evaluated in 46 accesses in which balloon angioplasty had to eventually be performed. The whole group consisted of 30 forearm AVF, 5 upper arm AVF and 11 AVG. Pressures were compared in each patient at a time of satisfactory access flow (QVA) and immediately before the angioplasty and pressure difference over that period (deltaPV, deltaPIA) evaluated. Despite a significant drop in QVA over the follow-up interval in both AVF and AVG, the mean deltaPV and deltaPIA in AVF were only several mm Hg and the chosen threshold limit of 20 mmHg was exceeded in approximately 10% of patients only. The results in the AVG group were, however, very different: The mean deltaPV and deltaPIA were close to 20 mmHg and almost 60% of patients in the AVG group exceeded this limit. Evaluation of PIA did not improve stenosis detection in either group. It is concluded that PV and/or PIA monitoring may be useful to detect a stenosis in AVG but not in AVF.

EDTNA/ERCA vascular access recommendations for nephrology nurses

In 1989, SJ. Schwab stated that providing satisfactory vascular access for haemodialysis remains one of the most challenging problems confronting the nephrology team (1). Successful long-term haemodialysis in patients with end-stage renal failure depends to a large extent upon a trouble-free vascular access. Unfortunately, the creation as well as the use, maintenance and the treatment of vascular access complications nowadays still remain a serious clinical problem despite pharmacological and technical advances during the last decade (2). Even today, vascular access failure and complications form a major cause of morbidity leading to a high percentage (20 to 30 %) of hospitalization in the dialysis population (3). Moreover, we are confronted all over the world with a clinically complicated patient population, such as diabetics, patients with advanced atherosclerosis, cardiac and peripheral vascular diseases. Also the increased blood viscosity due to the systematic use of erythropoietin and the use of high blood flows in modern dialysis therapy necessitates a vascular access of excellent quality.

Vascular access in acute renal failure

Today, central venous access catheters play an important role in the treatment and management of many dialysis patients. Their use and care may influence the patient's overall outcome. Therefore, it is critical to have a thorough knowledge of the vascular anatomy, types of catheters, placement techniques and maintenance and management of complications. The incidence nowadays of acute renal failure in intensive care patients is reported as high as 25%. Acute renal failure is one of the few causes of organ failure in which complete recovery is possible, provided the patient survives the associated comorbid conditions. There are various extracorporeal dialysis techniques available to treat this category of patients using mostly a central dialysis catheter as vascular access. It is important to select carefully the type of catheter and to create a specific vascular access system in order to be able to perform the selected dialysis technique in the most optimal efficient conditions. Any inadequacies of access will create dialysis insufficiency leading to more comorbid conditions and even higher mortality. In this article, we will describe the different possibilities as well as the nursing management of that type of vascular access in patients with acute renal failure.

Belgian peer review experience on the Achille's Heel in haemodialysis care: vascular access

AIMS

In order to improve the supervision and to evaluate the quality of care in dialysis units, a national project was promoted as a Peer Review. It consisted of systematic, continuous and critical evaluation of the care and the application of international guidelines and compared the reality of care with standards.

METHOD

The first chart consisted of the evaluation of infectious episodes of vascular access. This point is particularly relevant since infection represents the second cause of mortality in haemodialysis. A questionnaire concerning each patient was designed. Questions concerned the description of vascular access and the related infectious events. Each questionnaire included 21 items. The project involved 29 dialysis centres, 1,644 patients and 1,775 vascular accesses. The database included 90,525 data.

RESULTS

Among the 29 centres, the native arteriovenous fistula (AVF) is the first choice (67.5%) in vascular access, but the proportion of AVF decreases with age contrary to the catheter, which is more frequently chosen, in older patients. Independent of age, 20% of hospitalisations are among patients with catheters and only 7% among patients with AVF. The RR (relative risk) of being hospitalised (any complication of vascular access) is 1.68 for patients with catheters compared to patients with AVF. The rate of infections does not increase with age but is higher for patients with catheters (RR = 2.26). The number of infections appears to be dependent on the staphylococcus aureus carriage in the year.

CONCLUSIONS

This first step allows each centre to compare itself to others in an anonymous way. This approach should lead to specific recommendations to improve the quality of care in dialysis units.

Vascular access: a role for a renal nurse clinician

The team approach to the delivery of healthcare is important and has become more so since the boundaries between professional groups have become blurred. Renal replacement therapy requires that patients have adequate access. This could be in the form of an arterio-venous fistula, a graft, or a vascular catheter. Doctors have historically always provided access for patients. Placement of vascular access is a lengthy process often causing long delays and anxiety. Due to the reduction in junior doctors hours and the further demands on senior medical staff, a nurse was nominated and developed the role of vascular access specialist and clinician. Before the development of the nurse clinicians' role, the situation in this centre regarding venous access for haemodialysis was based on an ad hoc arrangement between junior doctors. Historically surgeons and medical staff have always provided vascular access for haemodialysis. However, it was felt that a suitably educated renal nurse would be more suitable to develop this role, and a relevant course, (MSc in Advanced Nursing Practice) had been developed at a nearby university. The access role included the insertion of both short and long-term vascular access catheters. An access referral pathway is now in place, giving a streamlined service. A designated access specialist nurse now inserts vascular access, providing focused individualised care specifically targeted at the renal patients' needs. Because of the success of this role, four more nurses are being supported to undertake the clinical MSc. The aim is to develop other areas of renal provision and to provide a nurse led specialist individualised service in line with the future National Service Framework. The role has also provided scope for nursing career development, giving motivation to experienced clinical nurses who wish to remain clinically involved, improve the care for patients and progress their career.

Effect of integrated education on nurses' knowledge of haemodialysis vascular access

The success of haemodialysis depends on access to the circulation. Preservation of the access site should be a primary goal of patient care. Little research on nursing interventions related to vascular access exists. Access care varies from centre to centre and there are often no written protocols for guidance. The aim of the study was to determine the effect of integrated education on nurses' knowledge. The fundamental principles of vascular access should be used to help train future dialysis staff members in order to improve quality of care. We must continue to gain knowledge in this important area through nursing research and education. This research demonstrates that integrated education improves the knowledge of nurses working in a renal unit.

Antiphospholipid antibodies and hemodialysis vascular access thrombosis

Screening for the presence of APL for hemodialysis dependent individuals is yet another critical link where medical and nursing interventions will prolong vascular access survival and decrease morbidity. Because of the continuity they provide, hemodialysis nurses and advanced practice nurses are in excellent positions to identify individuals with persistent vascular thrombosis and make recommendations for further screening.

Review of arteriovenous fistula care

The patient with End Stage Renal Failure is largely dependent upon haemodialysis for survival. Vascular access is the vital lifeline. This paper provides a review of the literature and aims to advocate the advantages of arteriovenous fistulae compared with other vascular access. It will discuss the main causes of thrombosis in arteriovenous fistula failure, measurements of early detection of venous stenosis and the care of an arteriovenous fistula to ensure its patency. The responsibility of the dialysis nurse is also considered.

The utilisation of shared governance to improve vascular access catheter care

This article looks at the implementation of shared governance at directorate level and its role in improving vascular access catheter care.

Hemodialysis vascular access monitoring for stenosis

A program evaluation of hemodialysis vascular access monitoring was undertaken to determine the effectiveness of serial, objective measurement, running venous dialysis pressures, in reducing access thrombosis in arterio-venous fistulae, as well as to assess the feasibility of long-term, routine monitoring for clients in a limited-care community hemodialysis unit. In all, 102 of 112 eligible patients participated in the study with a 98% compliance rate. Angiography confirmed stenosis in all eight performed for elevated venous pressures and 16 of 20 performed for clinical suspicion. Venous pressure frequency distributions indicated significantly lower venous pressures in lower arm arterio-venous fistulae than in upper arm arteriovenous fistulae or PTFE grafts. Running venous dialysis pressures are effective and feasible for predicting venous stenoses in arteriovenous fistulae in a limited care community hemodialysis unit. Lower and differentiated threshold pressures would increase the sensitivity of this screening tool; the effect on specificity would have to be evaluated.

CQI: hemodialysis vascular access flow monitoring

One of the main ongoing challenges in nephrology is maintaining a good, well-functioning vascular access. Vascular access problems lead to complications such as access recirculation causing decreased adequacy of dialysis as shown by kinetic modelling and access clotting. Access flow measurement using ultrasound dilution technique is an accurate and better indicator of impending access stenosis than recirculation (urea method). The measurement is non-invasive, the procedure simple, and the monitor accessible at the bedside. The Adam Linton Dialysis Unit of the London Health Sciences Centre, Victoria Campus is currently monitoring access flows (Qa) as a continuous quality initiative using ultrasound dilution technique. Access recirculation (AR) is determined and Qa measurements are done bimonthly on all chronic in-centre and self-care dialysis patients with either arteriovenous fistula or Gore-tex grafts. Qa's of <550 ml/min or 20% decrease in flows are investigated by angiography and early intervention is instituted either by angioplasty or fistula repair. Our unit's goal is to be proactive in our investigation and in our nursing and medical interventions. From our experience, the problem with responding to poor clearances by checking for recirculation after the fact is that valuable time is lost for proactive intervention to preserve the access site and may in fact be too late. In four different patient situations we are able to show how our different interventions have improved Qa's and eliminated AR resulting in increased Kt/V. The intent of this article is to show that Qa measurement can be an ideal way to monitor hemodialysis vascular accesses over time. It provides a means to detect impending access dysfunction before the Qa has decreased enough to have induced AR and/or under-dialysis. By early intervention, optimum dialysis efficiency is achieved and the prescribed Kt/V [urea] is delivered.

Prolonging access function and survival: the nurse's role

Vascular access is the lifeline of all patients undergoing haemodialysis (HD). In a recent patient satisfaction survey, the area of vascular access and needling technique was highlighted as an area with the need for improvement. This is addressed in this paper by the formulation of: Individual Access Vulnerability Score; an Access Care Plan, and implementation of a staff cannulation training programme. Addressing these three areas of practice with a structured programme not only assists staff to develop and value patient access but ultimately provides a higher quality of service. Patient satisfaction, access complications, staff knowledge, and clinical abilities can all be improved by the implementation of a more structured approach to developing and valuing vascular access.

Recommendations for tracking arteriovenous access complications using a charting-by-exception model

Due to a high number of vascular access revisions among hemodialysis patients, there is a great need to solidify methods to accurately assess, document, and track complications. This article presents an overview of the charting-by-exception (CBE) documentation model, which can enhance early identification and management of long-term AV access complications.

Warfarin sodium (Coumadin) anticoagulant therapy for vascular access patency

The increase of geriatric and diabetic patients with poor vasculature brings about a corresponding increase in the use of synthetic vascular access grafts. Synthetic vascular accesses are plagued with numerous problems in maintaining patency. As a result, many practitioners use warfarin sodium. Coumadin, because of its predictability and bioavailability to interrupt the coagulation cascade to prevent thrombus formation. This article includes actions, interactions, monitoring, and adverse effects of this drug.

Theoretical and practical issues in recirculation; assessment of vascular access

Haemodialysis recirculation is defined as the fraction of cleared extracorporeal blood flow which returns to the inlet of the extracorporeal blood line without systemic equilibration. There are two components of haemodialysis recirculation: the local component is related to access function and placement of access needles; the cardiopulmonary component is a characteristic of the peripheral arterio-venous access where access blood flow bypasses systemic tissue compartments. Identification of access problems requires separation of the two components using newly developed indicator dilution techniques such as ultrasound dilution. If such techniques are not available and recirculation is determined by techniques which measure combined effects of recirculation such as the urea technique, a second recirculation measurement with reversed placement of blood lines will permit us to distinguish between correct and reversed placement of blood lines. The larger of the two recirculation values can be used to identify accesses with insufficient access flow and access recirculation which require immediate intervention.