Intradialytic hypotension: frequency, sources of variation and correlation with clinical outcome.

Intradialytic hypotension (IH) is a frequent complication of hemodialysis (HD) and is associated with increased patient mortality and cardiovascular events. We studied IH to determine its variability, correlates, and clinical impact in 13 outpatient HD facilities. Blood pressure was captured by machine download. IH was defined as >30 mmHg decrease in systolic blood pressure to <90 mmHg. Risk factors were assessed by logistic regression and hospitalization by Poisson regression. Time to death and first hospitalization were assessed using Kaplan-Meier analysis in patients completing >20 HD treatments. We studied IH in 44,801 treatments (Tx) in 1137 patients. IH was frequent (17.2% of treatments) and highly variable by patient (0-100% Tx) and dialysis facility (11.1-25.8% Tx). 25.1% of patients had no IH (0% Tx) and 16.2% had IH on >35% Tx. Increased IH frequency was associated with age, female gender, diabetes, Hispanic origin, longer end stage renal disease vintage, higher body mass index, higher ultrafiltration volume, the second and third weekly Tx, lower pre-HD systolic blood pressure, higher difference between prescribed and achieved post-HD weight, and higher dialysate temperature. Dialysis facility was an independent predictor of IH frequency. Patients with >35% IH treatments had poorer survival (P = 0.036), and more frequent and longer hospitalization (P = 0.04, P = 0.002, respectively) than patients without IH. In conclusion, IH frequency was highly variable, associated with individual facilities, patient and treatment characteristics, and correlated with mortality and hospitalization. Identifying practice patterns associated with IH coupled with routine reporting of IH will facilitate medical management and may result in the prevention of IH, decreased mortality, and decreased hospitalization.

Variability of predialytic, intradialytic, and postdialytic blood pressures in the course of a week: a study of Dutch and US maintenance hemodialysis patients.

BACKGROUND: Patients with thrice-weekly hemodialysis have higher predialysis weights and ultrafiltration rates at the first compared with subsequent dialysis sessions of the week. We hypothesized that these variations in weight and ultrafiltration rate are associated with a systematic difference in blood pressure. STUDY DESIGN: Observational study. SETTING & PARTICIPANTS: During 3 months, we prospectively collected hemodynamic data for 4,007 hemodialysis sessions involving 124 Dutch patients. A similar analysis was performed with 789 US patients, comprising 6,060 hemodialysis sessions. FACTOR: First versus subsequent hemodialysis sessions of the week. OUTCOMES: Blood pressure. MEASUREMENTS: Blood pressure, weight, and ultrafiltration rate were analyzed separately for the first, second, and third dialysis sessions of the week. Comparisons were made with linear mixed models. RESULTS: In Dutch patients, predialysis weight and ultrafiltration rate were significantly greater at the first compared with subsequent hemodialysis sessions of the week (P < 0.001). Predialysis systolic and diastolic blood pressures were higher at the first than at subsequent sessions of the week (P < 0.001). Predialysis blood pressure differences persisted throughout the session: systolic and diastolic blood pressures were on average 5.0 and 2.5 mm Hg higher during the first compared to the third session of the week. Postdialysis blood pressures followed a similar pattern (P < 0.001). Blood pressure differences between the first and subsequent days of the week persisted after adjustment for possible confounders. Results in the US cohort were materially identical despite differences in patient characteristics and treatment practice between the 2 cohorts. LIMITATIONS: Dry weight was not assessed by objective methods. CONCLUSIONS: Blood pressure of patients on a thrice-weekly dialysis schedule varies systematically over the week. Predialysis blood pressure is highest at the first hemodialysis session of the week, most likely due to greater interdialytic weight gain. Intra- and postdialytic blood pressures also are highest at the first session of the week despite higher ultrafiltration rates.

Effects of citrate acid concentrate (citrasate®) on heparin N requirements and hemodialysis adequacy: a multicenter, prospective noninferiority trial.

BACKGROUND: Citrasate®, citric acid dialysate (CD), contains 2.4 mEq of citric acid (citrate), instead of acetic acid (acetate) as in standard bicarbonate dialysate. Previous studies suggest CD may improve dialysis adequacy and decrease heparin requirements, presumably due to nonsystemic anticoagulant effects in the dialyzer. METHODS: We prospectively evaluated 277 hemodialysis patients in eight outpatient facilities to determine if CD with reduced heparin N (HN) would maintain dialyzer clearance. Subjects progressed through four study periods [baseline (B): bicarbonate dialysate + 100% HN; period 1 (P1): CD + 100% HN; period 2 (P2): CD + 80% HN; period 3 (P3): CD + 66.7% HN]. The predefined primary endpoint was noninferiority (margin -8%) of the percent change in mean dialyzer conductivity clearance between baseline and P2. RESULTS: Subjects were 57.4% male, 41.7% white, 54.3% black, and 44.4% diabetic; mean age was 59 ± 14.4 years; mean time on dialysis was 1,498 ± 1,165 days; 65.7% had arteriovenous fistula, 19.9% arteriovenous graft, 14.4% catheters, and 27.8% used antiplatelet agents. Mean dialyzer clearance increased 0.9% (P1), 1.0% (P2), and 0.9% (P3) with CD despite heparin reduction. SpKt/V remained stable (B: 1.54 ± 0.29; P1: 1.54 ± 0.28; P2: 1.55 ± 0.27; P3: 1.54 ± 0.26). There was no significant difference in dialyzer/dialysis line thrombosis, post-HD time to hemostasis, percent of subjects with adverse events (AEs), or study-related AEs. CONCLUSIONS: CD was safe, effective, and met all study endpoints. Dialyzer clearance increased approximately 1% with CD despite 20-33% heparin reduction. Over 92% of P3 subjects demonstrated noninferiority of dialyzer clearance with CD and 33% HN reduction. There was no significant difference in dialyzer clotting, bleeding, or adverse events.

Improving the delivery of coordinated and individualized care.

Pharmatech comprises systems for the automated use and coordination of clinical information, medical devices, care paths, and pharmacologic agents into specific prescription and care-delivery processes tailored to meet individual patient needs. In ESRD, future suites of applications to run on hemodialysis, peritoneal dialysis machines, external computers and devices both in-center and in the home setting offer the potential to further automate billing and inventory, improve documentation, reduce medical errors, and decrease costs. On a clinical basis, these systems will aid nurses, physician assistants, nurse practitioners, and physicians in performing and overseeing a wide range of clinical activities that constitute 21st-century medicine. Future innovations may allow Pharmatech systems to learn by achieving defined outcomes. These developments offer the potential to provide customized ESRD care by integrating standard practices with individual patient characteristics and patient-specific needs. The development of Pharmatech represents one of the next advances in healthcare technology and will become an important component in the delivery of 21st-century medicine. Adoption of information technology (IT) has been prioritized by the federal government, and is a key component of US healthcare policy. The United States Agency for Healthcare Research and Quality is currently funding the development and implementation of a wide array of health IT applications. This extensive funding combined with rapid technologic advances will continue to drive Pharmatech development and the widespread implementation of medical IT in the coming decade.

Focused vascular access education to reduce the use of chronic tunneled hemodialysis catheters: results of a network quality improvement initiative.

Tunneled hemodialysis catheters (TDCs) carry the highest mortality risk for chronic hemodialysis patients of any access modality. Recent data have emphasized that mortality risk decreases when these devices are discontinued. Herein, we present the results of a gap-reduction assisted catheter elimination strategy that Network 7 employed as its quality improvement initiative to reduce the use of TDCs. Hemodialysis facilities with high catheter rates (>90 days) were identified. Interventions included focused vascular access education, monthly follow-up and site visits to assist the facility catheter reduction program. The "goal" of interventions was defined as the gap-reduction of 50% from the baseline catheter rate to the Network mean plus sustainability of catheter reduction for at least 3 consecutive months. Fifteen facilities (n = 891) were identified with high catheter rates (31.5 +/- 5.3%) in May 2006. Interventions resulted in a catheter reduction to 12.2 +/- 8.5% in May 2007 (p = 0.0001). Five of the 15 facilities (n = 280) achieved the goal (preintervention = 31.7 +/- 5.3%, postintervention = 8.7 +/- 2.8%, p = 0.001). In May 2007, eight additional facilities (n = 438) with high catheter rates (31.7 +/- 7.8%) were added to the 10 that failed to achieve the goal previously. Interventions employed in these 18 facilities (n = 1,049) resulted in catheter reduction in all (preintervention = 31.5 +/- 5.5%, postintervention = 16.2 +/- 5%, p = 0.01). Five of these 18 met the goal (preintervention = 32 +/- 8%, postintervention = 5.9 +/- 4.3%). Overall, all 23 facilities (n = 1,329) demonstrated catheter reduction postintervention (preintervention = 31.6 +/- 6%, postintervention = 13.9 +/- 6%, p = 0.001), and 10/23 (43%) met the project goal (preintervention = 31.9 +/- 6%, postintervention = 7.3 +/- 4%, p = 0.002). Medical director's involvement had a positive impact in achieving the goal (p = 0.003). The presence or absence of a vascular access coordinator did not affect catheter reduction. The results of this analysis reveals that an organized approach implemented by an ESRD Network can have a significant impact in reducing catheter use.

Home hemodialysis: a comparison of in-center and home hemodialysis therapy in a cohort of successful home hemodialysis patients.

We retrospectively evaluated 29 patients dialyzed for 6 months in-center on Fresenius 2008H or 2008K dialysis machines followed by 6 months at home using the Fresenius 2008K@home to determine the safety and efficacy of home hemodialysis (HHD) using the 2008K@home. Patients who initiated HHD were identified from order records and qualified for inclusion if they had available records and a minimum of three pre- and postdialysis blood urea nitrogen measurements during each period. Dialysis adequacy (mean standard weekly Kt/V) remained stable during the in-center (IC; 2.3 +/- 0.7 start, 2.3 +/- 0.7 end) and home periods (2.4 +/- 0.6 start, 2.5 +/- 0.7 end). During the home period, the percentage of delivered/prescribed single pool Kt/V was 96% +/- 12%; delivered/prescribed treatment time 98% +/- 10%; delivered/prescribed blood flow 95% +/- 7%, and delivered/prescribed dialysate flow was 99% +/- 8%. Twelve patients had 69 adverse events (5.84/100 treatments) IC and 18 patients had 40 (3.34/100 treatments) at home. No deaths were reported. In conclusion, a group of successful HHD patients received their prescribed hemodialysis therapy with the same or better adequacy as provided IC with no increase in adverse events. This demonstrates that selected patients can deliver HHD as safely and effectively as when receiving hemodialysis IC.

Vascular access: the past, present and future.

Over the past 40 years, improvements in vascular access management have enhanced patient outcomes and decreased an epidemic of access failure. Arteriovenous fistulae are again the access of choice and new percutaneous therapies and outpatient access centers have revolutionized the therapeutic approach to access failure. Evidence-based guidelines, supported by national and international outcome data have helped rationalize vascular access care. Current challenges and, in particular, the increased use of catheters with resultant increases in patient morbidity and mortality must be rapidly addressed to protect patients and decrease the unacceptably high rates of catheter-related infection. Future technologies will continue to improve vascular access management. Our ability to utilize these new approaches to benefit patients will depend on appropriate application, continued development of standardized delivery systems utilizing outcome measures and payment systems that support and incent outcome improvement.

Facility hemodialysis vascular access use and mortality in countries participating in DOPPS: an instrumental variable analysis.

BACKGROUND: Previously, the Dialysis Outcomes and Practice Patterns Study (DOPPS) has shown large international variations in vascular access practice. Greater mortality risks have been seen for hemodialysis (HD) patients dialyzing with a catheter or graft versus a native arteriovenous fistula (AVF). To further understand the relationship between vascular access practice and outcomes, we have applied practice-based analyses (using an instrumental variable approach) to decrease the treatment-by-indication bias of prior patient-level analyses. STUDY DESIGN: A prospective observational study of HD practices. SETTING & PARTICIPANTS: Data collected from 1996 to 2004 from 28,196 HD patients from more than 300 dialysis units participating in the DOPPS in 12 countries. PREDICTOR OR FACTOR: Patient-level or case-mix-adjusted facility-level vascular access use. OUTCOMES/MEASUREMENTS: Mortality and hospitalization risks. RESULTS: After adjusting for demographics, comorbid conditions, and laboratory values, greater mortality risk was seen for patients using a catheter (relative risk, 1.32; 95% confidence interval, 1.22 to 1.42; P < 0.001) or graft (relative risk, 1.15; 95% confidence interval, 1.06 to 1.25; P < 0.001) versus an AVF. Every 20% greater case-mix-adjusted catheter use within a facility was associated with 20% greater mortality risk (versus facility AVF use, P < 0.001); and every 20% greater facility graft use was associated with 9% greater mortality risk (P < 0.001). Greater facility catheter and graft use were both associated with greater all-cause and infection-related hospitalization. Catheter and graft use were greater in the United States than in Japan and many European countries. More than half the 36% to 43% greater case-mix-adjusted mortality risk for HD patients in the United States versus the 5 European countries from the DOPPS I and II was attributable to differences in vascular access practice, even after adjusting for other HD practices. Vascular access practice differences accounted for nearly 30% of the greater US mortality compared with Japan. LIMITATIONS: Possible existence of unmeasured facility- and patient-level confounders that could impact the relationship of vascular access use with outcomes. CONCLUSIONS: Facility-based analyses diminish treatment-by-indication bias and suggest that less catheter and graft use improves patient survival.

Increasing AV fistulae and decreasing dialysis catheters: two aspects of improving patient outcomes.

Maximizing arteriovenous (AV) fistula prevalence and minimizing catheter use have become the dominant issues in hemodialysis vascular access management and offer the promise of improved patient outcomes with decreased overall expenditures. Recent efforts have increased AV fistula prevalence in the US to 42.9% with regional rates as high as 59.5% and with complementary declines in AV grafts. This should decrease access procedures but may not fully realize the potential reductions in mortality and cost possible if combined with catheter reduction. Successful catheter reduction requires similar approaches to those utilized in the Fistula First Program. Educating patients, the use of clearly defined protocols and updating payment systems to include chronic kidney disease care are crucial to continued progress. Expansion of the Fistula First Program to include a focus on decreasing catheter prevalence and complications should be considered as a requirement in the push toward the breakthrough targets of 66% AV fistula prevalence.

Predicting hospitalization and mortality in end-stage renal disease (ESRD) patients using an Index of Coexisting Disease (ICED)-based risk stratification model.

We evaluated the use of an additive Index of Coexisting Diseases (ICED)-based stratification schema to determine subsequent hospitalization and mortality in a hemodialysis population. Patients from five commercial health plans were stratified into low-, medium-, and high-risk groups and followed for up to 1 year. Patients were reassessed and restratified at 90-day intervals and censored when disease management ceased. Outcome measures collected through selfreports and health plan records were captured in an active database. Survival to first hospitalization/ mortality was compared by Kaplan Meier curves, survivor function differences by the Wilcoxon test, and group comparisons by ANOVA and chi square. Population characteristics included mean age of 63.0, 57.7% male, and 58.8% diabetic. Mortality was 13.0% per patient year (standardized mortality ratio 0.43) and the hospitalization rate was 0.59 per patient year (standardized hospitalization ratio 0.24). Survival curves demonstrated differences in mortality and hospitalization between the patients in different initial risk categories (p < 0.01). Mean hospitalizations were 0.81 +/- 1.53 per patient year (high risk), 0.45 +/- 0.99 (medium risk), and 0.15 +/- 0.51 for the low-risk group (p < 0.001). Stratification was dynamic; 47.3% decreased and 4.7% increased risk level between the first and second assessment. These changes were associated with survival differences for initial low (p = 0.06) or medium patients (p < 0.01), and hospital-free survival for initial medium (p = 0.08) or high patients (p < 0.05). In conclusion, this ICED-based stratification schema predicted mortality and hospitalization for hemodialysis patients participating in our disease management program.

Disease management improves end-stage renal disease outcomes.

BACKGROUND/AIMS: Renal disease management organizations have reported achieving significant decreases in mortality and hospitalization in conjunction with cost savings, improved patient satisfaction and quality of life. Disease management organizations strive to fill existing gaps in care delivery through the standardized use of risk assessment, predictive modeling, evidence-based guidelines, and process and outcomes measurement. Patient self-management education and the provision of individual nurse care managers are also key program components. METHODS: As we more fully measure clinical outcomes and total healthcare costs, including payments from all insurance and government entities, pharmacy costs and out of pocket expenditures, the full implications of disease management can be better defined. RESULTS: The results of this analysis will have a profound influence on United States healthcare policy. CONCLUSION: At present current data suggest that the promise of disease management, improved care at reduced cost, can and is being realized in end-stage renal disease.

Vascular access monitoring improves outcomes.

Vascular access monitoring can identify patients at increased risk of future access thrombosis. When coupled with a program of elective stenosis correction, access thrombosis rates decline approximately 50-75%. This results in arteriovenous (AV) fistula thrombosis rates of 0.1-0.2/patient year (vs. 0.2-0.4 at baseline) and AV graft thrombosis rates <0.5/patient year (vs. 0.8-1.2 thromboses/patient year at baseline). Evaluating the long-term impact on access survival remains problematic. There are no large-scale randomized trials and existing studies exhibit marked differences in target populations, clinical protocols and outcome definitions. Differences in payment systems also significantly influence the efficacy of monitoring and intervention programs. Despite these challenges, the current data support the K/DOQI recommendations that all patients undergo a program of regular access monitoring preferably by access flow measurement coupled with prompt imaging and elective stenosis correction for low flow accesses.

Improving vascular access outcomes: a systems approach to eliminating structural barriers.

Maximizing AV fistula creation, regular access monitoring, prompt outpatient interventions and minimizing catheter use are well-accepted approaches for vascular access management. Systemic barriers impede the application of these strategies. A misaligned reimbursement system coupled with educational deficits and a lack of accountability has contributed to the institutionalization of substandard vascular access care. The hallmark of performance management is to create systems in which incentives are aligned to produce desired behaviors. Realigning reimbursement through a combination of pre-ESRD funding, enhancements to the composite rate to reward outcomes and cover vascular access monitoring and updated reimbursement for outpatient vascular access procedures would improve care and decrease unnecessary hospitalizations. This should be coupled with clearly defined outcome standards and accountability incorporated into hospital accreditation and credentialing. Capitation may provide alternative solutions. A two-phased approach including reimbursement reform while exploring capitation represents a prudent course with the best likelihood of success.

Systemic barriers to improving vascular access outcomes.

Vascular access dysfunction is the most frequent cause of hospitalization for end-stage renal disease (ESRD) patients. Our system of vascular access care and industry standards developed for historic reasons have resulted in a haphazard approach to access management. The Dialysis Outcome Quality Initiative has provided a road map for improving vascular access management. However, despite widespread acceptance, these recommendations are not routinely followed. This is largely the result of inertia coupled with systemic barriers to improving access outcomes. These barriers include lack of funded pre-ESRD care and preoperative imaging, lack of reimbursement for access monitoring, unavailable surgical and interventional suites, erosion of the real value of the composite rate, bundling of additional new services without rate adjustment, poor accountability of surgeons and hospitals, and a reimbursement system that rewards procedures and, in particular, graft and catheter placement. Currently, Center for Medicare and Medicaid Services is reevaluating the composite rate and its included bundle of services. To provide the best access care with the fewest complications while insuring multidisciplinary involvement and accountability, a realistic appraisal and realignment of incentives must be developed to insure improvement of access care in the United States.

The role of color flow Doppler ultrasound in dialysis access.

Color flow Doppler provides accurate imaging and access flow volume measurement of the hemodialysis vascular access. It can readily identify subsets of patients at high risk for future thrombosis. It is noninvasive, mobile, and allows convenient clinical evaluation at the dialysis facility. In Europe, Doppler ultrasound has become the standard of care for evaluation of arteriovenous (AV) fistula dysfunction and is essential in the preoperative evaluation for access placement. It also can diagnose the arterial inflow disease that has become more prevalent in our aging, diabetic, end-stage renal disease (ESRD) population. Access management programs based on Doppler ultrasound have been highly successful and have produced outcome data as good or better than provided with other techniques. In light of its proven clinical efficacy, reimbursement and regulatory agencies should allow its appropriate inclusion into integrated access management programs. In conclusion, Doppler ultrasound should be included as a part of an integrated vascular access management program. This is supported by clinical outcome data and direct comparisons with other modalities.