The use of tunneled dialysis catheters to deliver hemodialysis treatment may be associated with major problems. For this reason their use should be minimized as much as possible. Infection is the most serious of these problems. This complication causes very significant morbidity and mortality and has emerged as the primary barrier to long-term catheter use. Bacteremia is the most serious type of infection associated with catheter use. It can result in metastatic infection and even lead to death of the patient. Prophylaxis is important to decrease the risk of infection. The use of an antibiotic ointment at the exit site until it has healed and the long-term use of a dressing to cover the exit site are effective in decreasing the incidence of exit-site infection. With optimal catheter-use management, it should be possible to reduce the incidence of catheter-related bacteremia (CRB) to a level in the range of 1 ⁄ 1000 catheter days. Antibiotic and antimicrobial locking solutions show promise and may, if verified in appropriate clinical studies, prove to be important adjuncts to the management of catheterdependent patients. Aspirin has been shown to have anti-staphylococcal activity and warrants further clinical evaluation. The diagnosis of CRB is based upon positive blood cultures in association with typical clinical features. If a simple routine blood culture is positive, along with a high clinical probability based upon the patient's signs and symptoms, the sensitivity and specificity of the diagnosis is greater than 75%. CRB is in reality a biofilm infection and must be treated as such. Treatment needs to focus on appropriate systemic antibiotics which should be continued for a minimum of 3 weeks and catheter management to remove the biofilm. Catheter exchange has been shown to be effective and should be performed based upon the clinical presentation of the patient. While treatment with a combination of systemic antibiotics and antibiotic locking solution may be effective for gramnegative infections, this approach does not appear to be a good choice for Staphylococcus aureus CRB.The use of a tunneled dialysis catheter (TDC) to deliver hemodialysis (HD) treatment may be associated with major problems. Catheter dysfunction (inadequate flow) secondary to thrombosis and catheter-related infections are common occurrences. Although catheter dysfunction is the more common of the two complications, infection related to the use of a catheter is the more serious problem, representing a very significant cause of morbidity and mortality and has emerged as the primary barrier to long-term catheter use. The overall incidence of this problem can be appreciated from a review of the data generated by the HEMO study. This was a study of 1846 randomized HD patients designed primarily to evaluate the efficiency of dialysis, but secondarily also evaluated infection-related deaths and first infectionrelated hospitalizations. Catheters were present in 32% of all study patients admitted with access-related infection, even thoug...

IntroductionHemodialysis access-induced distal ischemia (HAIDI) has been reported to have an incidence of 1%-8%. 1 However, this is based on referred cases requiring surgical treatment. Its true frequency is dependent upon the symptom threshold used to qualify for the diagnosis. Systematic patient evaluation has shown that mild to moderate symptoms occur much more frequently. 2 The reported incidence relates to the upper extremity and is the topic of this review. Access-related distal ischemia can also involve the lower extremity with serious consequences. 3,4 An understanding of HAIDI and the appropriate role of the interventional nephrologist in its management is important when patients present with symptoms suggestive of HAIDI. Herein, the pathophysiology of the syndrome is discussed followed by recommendations for its diagnosis and management and the basis for the recommendations. These recommendations ASDIN white paper: Assessment and management of hemodialysis accessinduced distal ischemia by interventional nephrologists AbstractAlthough not common, hemodialysis access-induced distal ischemia is a serious condition resulting in significant hemodialysis patient morbidity. Patients with signs and symptoms suggestive of hand ischemia frequently present to the general and interventional nephrologist for evaluation. In order to care for these cases, it is necessary to understand this syndrome and its management. Most cases can be managed conservatively without intervention. Some cases requiring intervention may be treated using techniques within the scope of practice of the interventional nephrologists while other cases require vascular surgery. In order for the interventional nephrologists to evaluate and manage these cases in a timely and appropriate manner, practice guidelines are presented.

The procedure profile treated in freestanding, dedicated dialysis access centers changed significantly over 15 years, reflecting the changes that have occurred in the vascular access profile of the dialysis population.

Brachiocephalic arteriovenous fistulas (AVF) makeup approximately one third of prevalent dialysis vascular accesses. The most common cause of malfunction with this access is cephalic arch stenosis (CAS). The accepted requirement for treatment of a venous stenosis lesion is ⩾50% stenosis associated with hemodynamically abnormalities. However, the correlation between percentage stenosis and a clinically significant decrease in access blood flow (Qa) is low. The critical parameter is the absolute minimal luminal diameter (MLD) of the lesion. This is the parameter that exerts the key restrictive effect on Qa and results in hemodynamic and functional implications for the access. CAS is the result of low wall shear stress (WSS) resulting from the effects of increased blood flow and the unique anatomical configuration of the CAS. Decrease in WSS has a linear relationship to increased blood flow velocity and neointimal hyperplasia exhibits an inverse relationship with WSS. The result is a stenotic lesion. The presence of downstream venous stenosis causes an inflow-outflow mismatch resulting in increased pressure within the access. Qa in this situation may be decreased, increased, or within a normal range. Over time, the increased intraluminal pressure can result in marked aneurysmal changes within the AVF, difficulties with cannulation and the dialysis treatment, and ultimately, increasing risk of access thrombosis. Complete characterization of the lesion both hemodynamically and anatomically should be the first step in developing a strategy for management. This requires both access flow measurement and angiographic imaging. Patients with CAS present a relatively broad spectrum as relates to both of these parameters. These data should be used to determine whether primary treatment of CAS should be directed toward the anatomical lesion (small MLD and low Qa) or the pathophysiology (large MLD and high Qa).

Dialysis vascular access (DVA) care is being increasingly provided in freestanding office-based centers (FOC). Small-scale studies have suggested that DVA care in a FOC results in favorable patient outcomes and lower costs. To further evaluate this issue, data were drawn from incident and prevalent ESRD patients within a 4-year sample (2006-2009) of Medicare claims (USRDS) on cases who receive at least 80% of their DVA care in a FOC or a hospital outpatient department (HOPD). Using propensity score matching techniques, cases with a similar clinical and demographic profile from these two sites of service were matched. Medicare utilization, payments, and patient outcomes were compared across the matched cohorts (n = 27,613). Patients treated in the FOC had significantly better outcomes (p < 0.001), including fewer related or unrelated hospitalizations (3.8 vs. 4.4), vascular access-related infections (0.18 vs. 0.29), and septicemia-related hospitalizations (0.15 vs. 0.18). Mortality rate was lower (47.9% vs. 53.5%) as were PMPM payments ($4,982 vs. $5,566). This study shows that DVA management provided in a FOC has multiple advantages over that provided in a HOPD.

Data derived from a large cohort of hemodialysis patients (12,896) undergoing dialysis access maintenance procedures being performed by interventional nephrologists were analyzed to determine the safety of sedation/analgesia (S/A) in a freestanding facility. Data collected included patient demographics, procedures performed, time of procedures, drugs used, doses used, and complications that occurred. Four high-risk groups were identified based upon age, pulmonary status, and over all physical status. These were compared to the total cohort. Midazolam, fentanyl, or a combination of the two were used. Within the total cohort of patients, midazolam alone was used most commonly (94.7%). The total mean dose of midazolam when used alone was 3.4 mg. The dosages used in the high-risk groups tended to be only slightly lower (3-3.2 mg). This setting appears to be safe for hemodialysis patients, even those in high-risk subgroups having these types of procedures. The types of drugs and the dosages that are commonly used do not appear to be associated with an unacceptable risk to the hemodialysis patient. A nephrologist that is not specialty trained in anesthesia is able to provide S/A safely in a freestanding facility.

As with any type of medical procedure, endovascular procedures result in procedure-related complications (PRCs). A PRC system as part of an outcome-based practice monitoring strategy is essential. Such a program should have several features. It should be realistic, it should be standardized, it should have credibility, it must allow for comparisons with other physicians who are performing the same procedure, and it should be easily accomplished. Currently the only system in popular use is the system designed by the Society of Interventional Radiology (SIR). Definitions within this system are excessively broad and somewhat difficult to apply. This leads to inconsistencies. SIR indicates that their system is intended for use in publications of clinical research and may not be appropriate for use in routine clinical practice. There is a need for a system specifically aimed at and designed for day to day use by the practicing interventionalist whose work is not necessarily directed toward publication. We have described a system from the clinical applications viewpoint.

Based upon these data, it seems reasonable to classify the TDC placement procedure as having a very low risk of bleeding and to not require preprocedure laboratory testing. The value of suspending antithrombotic medications prior to TDC placement cannot be supported.