Patterns of emergency department utilization by patients on chronic dialysis: A population-based study.

IMPORTANCE: Patients on dialysis are often elderly and frail, with multiple comorbid conditions, and are heavy users of Emergency Department (ED) services. However, objective data on the frequency and pattern of ED utilization by dialysis patients are sparse. Such data could identify periods of highest risk for ED visits and inform health systems interventions to mitigate these risks and improve outcomes. OBJECTIVE: To describe the pattern and frequency of presentation to ER by dialysis patients. DESIGN: Retrospective cohort study using administrative data collected over ten years (2000-2009) in the Province of Manitoba, Canada. SETTING: Patients presenting to any of 9 ED's in Winnipeg and Brandon Manitoba. These departments serve >90% of the population of Manitoba, Canada (population 1.2 million). PARTICIPANTS: All patients presenting to an ED in any of 9 emergency departments in Manitoba, Canada. EXPOSURE: Dialysis status. MAIN OUTCOMES: Presentation to the ED. RESULTS: Over 2.1 million ED visits by more than 1.2 million non-dialysis patients and 17,782 ED visits by 3257 dialysis patients were included. Dialysis patients presented 8.5 times more frequently to the ED than the general population (age and sex adjusted, p<0.001). For dialysis patients, ED utilization was significantly higher following the long interdialytic interval (33.6% higher Mondays and 19.5% higher Tuesdays vs. other days of the week, p<0.001) and was 10-fold higher in the 7 days before and after the initiation of dialysis. CONCLUSION AND RELEVANCE: The heavy use of ED services by dialysis patients spikes upward following the long interdialytic interval and also in the week before and after dialysis initiation. The relative risks associated with these vulnerable periods were much higher than those reported for clinical patient characteristics. We propose that intrinsic gaps in the structure of care delivery (e.g. 3 times a week dialysis, imperfect surveillance and clinical monitoring of patients with low GFR) may be the fundamental drivers of this periodicity. Strategies to mitigate this excess health risk are needed.

Association between Duration of Predialysis Care and Mortality after Dialysis Start.

BACKGROUND AND OBJECTIVES: Early nephrology referral is recommended for people with CKD on the basis of observational studies showing that longer nephrology care before dialysis start (predialysis care) is associated with lower mortality after dialysis start. This association may be observed because predialysis care truly reduces mortality or because healthier people with an uncomplicated course of disease will have both longer predialysis care and lower risk for death. We examined whether the survival benefit of longer predialysis care exists after accounting for the potential confounding effect of disease course that may also be affected by predialysis care. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed a retrospective cohort study and used data from 3152 adults with end stage kidney failure starting dialysis between 2004 and 2014 in five Canadian dialysis programs. We obtained duration of predialysis care from the earliest nephrology outpatient visit to dialysis start; markers of disease course, including inpatient or outpatient dialysis start and residual kidney function around dialysis start; and all-cause mortality after dialysis start. RESULTS: The percentages of participants with 0, 1-119, 120-364, and ≥365 days of predialysis care were 23%, 8%, 10%, and 59%, respectively. When we ignored markers of disease course as in previous studies, longer predialysis care was associated with lower mortality (hazard ratio120-364 versus 0-119 days, 0.60; 95% confidence interval, 0.46 to 0.78]; hazard ratio≥365 versus 0-119 days, 0.60; 95% confidence interval, 0.51 to 0.71; standard Cox model adjusted for demographics and laboratory and clinical characteristics). When we additionally accounted for markers of disease course using the inverse probability of treatment weighted Cox model, this association was weaker and no longer significant (hazard ratio120-364 versus 0-119 days, 0.84; 95% confidence interval, 0.60 to 1.18; hazard ratio≥365 versus 0-119 days, 0.88; 95% confidence interval, 0.69 to 1.13). CONCLUSIONS: The association between longer predialysis care and lower mortality after dialysis start is weaker and imprecise after accounting for patients' course of disease.

An ethanol/sodium citrate locking solution compared to heparin to prevent hemodialysis catheter-related infections: a randomized pilot study.

PURPOSE: The objective of this study was to compare the initial safety and efficacy of a novel 30% ethanol/4% sodium citrate catheter-locking solution to heparin in a hemodialysis population. METHODS: This was a prospective, randomized, pilot study of 40 hemodialysis patients randomized to a 30% ethanol/4% sodium citrate or heparin 1000 units/mL locking solution. The primary outcome was identification of any serious adverse events over the study duration. Secondary outcomes included the rate per 1000 catheter days for catheter-related bloodstream infections (CRBSI), alteplase use, catheter dysfunction, and catheter removal. RESULTS: Three serious adverse events were reported as possibly related to the catheter solutions. Only one CRBSI was observed during the study in the heparin arm. The rate of alteplase use was 1.5/1000 catheter days in the heparin arm compared to 2.8/1000 catheter days in the ethanol/citrate arm (rate ratio = 1.85, 90% CI 0.48, 7.07, p value = 0.45), while the rate of catheter dysfunction was 6.8/1000 catheter days in the heparin arm compared to 1.9/1000 catheter days in the ethanol citrate arm (rate ratio = 0.27, 90% CI 0.10, 0.74, p value = 0.04). Catheter survival to first catheter outcome was longer in the ethanol/citrate group compared to heparin and there were no catheter removals due to bacteremia or thrombosis. CONCLUSIONS: The ethanol/sodium citrate locking solution was safely used in this study. It appears to prevent CRBSI and may improve catheter survival compared to heparin. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01394458.

Impact of modality choice on rates of hospitalization in patients eligible for both peritoneal dialysis and hemodialysis.

BACKGROUND: Hospitalization rates are a relevant consideration when choosing or recommending a dialysis modality. Previous comparisons of peritoneal dialysis (PD) and hemodialysis (HD) have not been restricted to individuals who were eligible for both therapies. ♢ METHODS: We conducted a multicenter prospective cohort study of people 18 years of age and older who were eligible for both PD and HD, and who started outpatient dialysis between 2007 and 2010 in four Canadian dialysis programs. Zero-inflated negative binomial models, adjusted for baseline patient characteristics, were used to examine the association between modality choice and rates of hospitalization. ♢ RESULTS: The study enrolled 314 patients. A trend in the HD group toward higher rates of hospitalization, observed in the primary analysis, became significant when modality was treated as a time-varying exposure or when the population was restricted to elective outpatient starts in patients with at least 4 months of pre-dialysis care. Cardiovascular disease, infectious complications, and elective surgery were the most common reasons for hospital admission; only 23% of hospital stays were directly related to complications of dialysis or kidney disease. ♢ CONCLUSIONS: Efforts to promote PD utilization are unlikely to result in increased rates of hospitalization, and efforts to reduce hospital admissions should focus on potentially avoidable causes of cardiovascular disease and infectious complications.

Choosing peritoneal dialysis reduces the risk of invasive access interventions.

BACKGROUND: Patients choosing between hemodialysis (HD) and peritoneal dialysis (PD) should be well informed of the risks and benefits of each modality. Invasive access interventions are important outcomes because frequent interventions lower patient's quality of life and consume limited resources. The objective of this study was to compare the risk of access interventions between the two modalities. METHODS: Three hundred and sixty-nine incident chronic dialysis patients were prospectively enrolled at four Canadian centers that were eligible for both modalities, received at least 4 months of pre-dialysis care and started dialysis electively as an outpatient. Two hundred and twenty-four (61%) chose PD and 145 (39%) chose HD. Patients were followed for an average of 1.3 years (range 0.07-3.6 years). RESULTS: In the PD group, there were fewer access interventions (2.5 versus 3.1 interventions per patient, adjusted odds ratio of 0.79 for PD versus HD, P = 0.005) and a lower intervention rate (2.3 versus 1.9 per patient-year, adjusted rate ratio of 0.81 for PD versus HD, P = 0.04). PD catheters were less likely to experience primary failure (4.6 versus 32%, P < 0.0001), showed a trend toward lower intervention rates during use (0.8 versus 1.2 per patient-year, P = 0.06), and had equal patency compared to fistulae (1-year patency of 84 versus 88%, P = 0.48). Patients managed exclusively with HD catheters (28% of the HD group) required 1.7 interventions per patient and an intervention rate of 1.9 per patient-year. CONCLUSION: Patients who choose PD require fewer access interventions to maintain dialysis access than patients choosing HD.

Obesity and obesity-related comorbidities in a Canadian First Nation population.

INTRODUCTION: Rates of obesity are higher among Canada's Aboriginal First Nations populations than among non-First Nations populations. We studied obesity and obesity-related illness in a Manitoba First Nation community. METHODS: We conducted a screening study of diabetes and diabetes complications in 2003, from which we drew a representative sample of Manitoba First Nations adults (N = 483). We assessed chronic disease and chronic disease risk factors. RESULTS: Prevalence of obesity and associated comorbidities was higher among women than men. By using multivariate analysis, we found that factors significantly associated with obesity among women were diastolic blood pressure, insulin resistance, and employment status. Among men, factors were age, apolipoprotein A1 level, apolipoprotein B level, and insulin resistance. Seventy-five percent of study participants had at least 1 of the following conditions: obesity, dyslipidemia, hypertension, or diabetes. Comorbidity was high even among the youngest age groups; 22% of men and 43% of women aged 18 to 29 had 2 or more chronic conditions. Twenty-two percent of participants had undiagnosed hypertension. Participants with undiagnosed hypertension had significantly more chronic conditions and were more likely to have microalbuminuria than were those without hypertension. The number of chronic conditions was not significantly different for participants with newly diagnosed hypertension than for those with previously diagnosed hypertension. CONCLUSION: The prevalence of obesity and other chronic conditions in the study community is high, especially considering the number of young people. Community-based interventions are being undertaken to reduce the excessive rate of illness.

Impact of contraindications, barriers to self-care and support on incident peritoneal dialysis utilization.

BACKGROUND: Targets for peritoneal dialysis (PD) utilization may be difficult to achieve because many older patients have contraindications to PD or barriers to self-care. The objectives of this study were to determine the impact that contraindications and barriers to self-care have on incident PD use, and to determine whether family support increased PD utilization when home care support is available. METHODS: Consecutive incident dialysis patients were assessed for PD eligibility, offered PD if eligible and followed up for PD use. All patients lived in regions where home care assistance was available. RESULTS: The average patient age was 66 years. One hundred and ten (22%) of the 497 patients had absolute medical or social contraindications to PD. Of the remaining 387 patients who were potentially eligible for PD, 245 (63%) had at least one physical or cognitive barrier to self-care PD. Patients with barriers were older, weighed less and were more likely to be female, start dialysis as an inpatient and have a history of vascular disease, cardiac disease and cancer. Family support was associated with an increase in PD eligibility from 63% to 80% (P = 0.003) and PD choice from 40% to 57% (P = 0.03) in patients with barriers to self-care. Family support increased incidence PD utilization from 23% to 39% among patients with barriers to self-care (P = 0.009). When family support was available, 34% received family-assisted PD, 47% received home care-assisted PD, 12% received both family- and home care-assisted PD, and 7% performed only self-care PD. Incident PD use in an incident end-stage renal disease (ESRD) population was 30% (147 of the 497 patients). CONCLUSIONS: Contraindications, barriers to self-care and the availability of family support are important drivers of PD utilization in the incident ESRD population even when home assistance is available. These factors should be considered when setting targets for PD.

Risk factors for infectious spondylodiscitis in patients receiving hemodialysis.

A retrospective case-control and cohort analysis of hemodialysis patients was done to identify risk factors for spondylodiscitis. These risk factors included bacteremia, receipt of blood products, invasive procedures, and establishment of vascular access. The death rate was greater for case subjects than for control subjects (odds ratio, 2.7).

Bayesian pharmacokinetics of gentamicin in a haemodialysis population.

BACKGROUND: Aminoglycosides are commonly used in the haemodialysis population. Standard pharmacokinetic approaches require multiple sampling to describe the parameters of drug distribution and elimination in the intra- and interdialytic periods. OBJECTIVE: To characterise the pharmacokinetics of gentamicin in a haemodialysis population by using Bayesian pharmacokinetic methods and only two plasma concentrations. DESIGN AND PARTICIPANTS: Prospective case series of 13 adult (aged 36-70 years) haemodialysis patients (Fresenius F80 dialysers were used) receiving gentamicin. METHODS: Patients with suspected or confirmed Gram-negative infections were given gentamicin. At 48 hours after receiving the dose (at the next haemodialysis session), patients provided two blood samples, one immediately before the dialysis session and another 1 hour after haemodialysis. Data on dosage, timing and plasma concentrations for all subjects were analysed with PASTRX version 10.6 and Bayesian pharmacokinetic analysis. Volume of distribution (Vd), interdialytic elimination rate constant (k(inter)), interdialytic elimination half-life (t1/2beta, inter)) and interdialytic clearance (CL(inter)) were determined from a single predialysis plasma concentration. Elimination rate constant (k(dial)), elimination half-life (t1/2beta, dial)) and clearance (CL(dial)) during 3.5-4 hours of dialysis were also determined from the pre- and post-plasma concentrations. RESULTS: Pharmacokinetic parameters (mean +/- SD) were: Vd 0.288 +/- 0.002 L/kg, k(inter) 0.015 +/- 0.004h(-1), t1/2beta, inter) 48 +/- 11h, CL(inter) 5.9 +/- 2.4 mL/min, k(dial) 0.25 +/- 0.05 h(-1), t1/2beta, dial) 3.0 +/- 1.0h and CL(dial) 91 +/- 24 mL/min. CONCLUSIONS: The rate of elimination of gentamicin was 17-fold greater (95% CI 13.7-20.7) on haemodialysis with a Fresenius F80 than off haemodialysis. All of the pharmacokinetic parameters of interest were determined using Bayesian pharmacokinetic procedures and only two plasma gentamicin concentrations.

Alteplase versus urokinase for occluded hemodialysis catheters.

BACKGROUND: The use of central venous catheters as a source of vascular access in patients undergoing hemodialysis may be complicated by thrombosis. Frequently, thrombolytics are used in an attempt to reestablish blood flow through partially or completely occluded catheters. OBJECTIVE: To compare the efficacy of alteplase (recombinant tissue plasminogen activator) versus urokinase in reestablishing adequate blood flow through partially or completely occluded vascular catheters. METHODS: Part 1 of the study prospectively investigated the effect of alteplase in reestablishing adequate blood flow through partially or completely occluded vascular catheters in 30 hemodialysis patients. Part 2 of the trial compared the efficacy of alteplase with that of urokinase in 14 of 30 patients who had also previously received urokinase. A 30-minute push-protocol was used to administer thrombolytics in both parts of the study. The primary endpoint was the proportion of patients with partially or completely occluded catheters achieving post-thrombolytic blood flow of > or =200 mL/min. RESULTS: Part 1 showed a large proportion of partially or completely occluded catheters achieving post-alteplase blood flows > or =200 mL/min (70/76, 92.1% vs. 34/40, 85%, respectively). In Part 2 of the study, the proportion of partially occluded catheters achieving post-thrombolytic blood flows > or =200 mL/min was not significantly different between the alteplase and urokinase groups, (36/41, 87.8% vs. 21/28, 75%, respectively; p = 0.205). The proportion of completely occluded catheters achieving post-thrombolytic blood flows > or =200 mL/min was significantly better with alteplase compared with urokinase (15/17, 88.2% vs. 6/14, 42.8%, respectively; p =.018). CONCLUSIONS: Alteplase, administered via the 30-minute push-protocol, is an effective thrombolytic for restoring hemodialysis catheter patency. In our study sample, alteplase was generally more effective than urokinase in restoring blood flow through catheters, especially those that were completely occluded.