Most patients diagnosed with End Stage Renal Disease (ESRD) undergo hemodialysis. Traditional hemodialysis treatment requires patients spending three to five hours every other day while yielding the high waste level accumulated between treatments. These limitations in the current technology have spurred the development of a portable renal replacement system. The portable system will not only free the patients from visiting the clinic but also allow more frequent treatment that will lead to lower average waste level. To realize a portable system, the size and weight of hemodialysis system components should be reduced. This work analyzes the working principle of the pump and proposes a DC-motor and cam driven finger pump design. In addition, an analytical pump model is created for the optimization of the pump design. In vitro experiment conducted using the pump measured Creatinine levels over time, and the results validitate the design for the portable renal replacement system. The proposed pump design is smaller than 188 cm³ and consumes less than 4W while providing a flow rate of more than 100ml/min (the optimum flow rate for a portable system) for both blood and dialysate flows. The smallest pump of a portable renal replacement system in the literature uses check valves, which considerably increase the overall manufacturing cost and possibility of clogging. Compared to that pump, the proposed pump design achieved reduction in size by 40% and savings in energy consumption by 65% with the removal of valves. This simple and reliable design substantially enables development of a portable renal replacement system.

Involving patients in medical decisions by acknowledging patients personal values and individual preferences has become an important goal of providing ethical medical care. Despite a general movement towards a model of shared decision-making, many patients do not fully meet their preferred role in practice. The decision whether or not to accept a kidney once it is offered to a patient awaiting transplant has historically been made predominantly by the transplant surgeon with little involvement from the patient. Because dialysis can provide long-term renal replacement, declining a kidney is a viable option. Patient changes over time and inherent heterogeneity of donor kidneys make this an authentic decision requiring careful analysis of costs and benefits from the patient perspective. The purpose of this study is to improve our understanding of how patients and transplant surgeons prioritize different factors when deciding whether or not to accept a kidney that has become available, in order to empower patients to become more involved in the decision-making process. Phase I: We developed a comprehensive list of factors that patients might consider important through qualitative interviews with patients, and deliberation with a transplant surgeon (SK) and a transplant nephrologists (RF). Phase II: We quantified the relative importance of each factor for patients on the transplant list and for transplant surgeons with a computerized survey using Maximum Differences Scaling. We developed relative importance scores using Heirarchical Bayes analysis, and tested for associations between patient characteristics and relative importance scores using Spearmans correlation coefficient and the Mann Whitney U test for continuous and categorical variables respectively. Of the factors evaluated, patients placed the greatest value on Kidney quality, How closely matched you are to the kidney, and How strongly your surgeon feels you should accept the kidney. Relative importance of different factors did not change based on patient demographic characteristics. Patients who are on the waiting list longer give less importance to kidney quality (standard beta estimate -0.23, p value 0.03) and more importance to How difficult it is for you to be matched to a donor (ie whether or not you are sensitized) (standard beta estimate 0.28, p value 0.01). Surgeons placed the greatest value on Kidney quality, How difficult it is for the patient to be matched to a kidney (ie whether or not the patient is sensitized), and The age of the donor. This pilot study suggests a role for standardized education tools to help empower patients to be involved in this difficult decision. Development of decision aids can be guided by the results of this project.

Many patients with end-stage renal disease come to rely on catheters as their only means of hemodialysis when other options are no longer viable. These patients have a very poor quality of life due to their chronic illness as well as many long-term complications related to the use of tunneled catheters. Many prior attempts have been made to understand these catheter-related problems. Yet, they continue to be a major cause of morbidity and mortality in chronic catheter-reliant patients. We hope to examine the rate as well as long term time course of these complications such that in future, we may decrease their occurrence. We predict that over time, chronic catheter use decreases the mean indwell time for each catheterization and increases the incidence of complications. To study this, we conducted a retrospective study looking at all patients who had three or more tunneled catheter exchanges between July 2003 and July 2008. We collected information from Yale IDX database on the patients age and gender, the type of catheter used, the indwell time of the catheter, the vessel used as access, the indication for catheter removal, whether the procedure was performed by a medical doctor (M.D.) or physicians assistant (P.A.) and whether it was a de novo insertion or over-the-wire exchange. We collected a total of 764 data points on 191 patients (89 males and 102 females). They ranged from 8 to 87 years old with a median age of 56 years. Infection was the number one indication for catheter removal at 37%. The rate of infection was 3.34 per 1,000 catheter days. There was no difference in the rate of complications by the side of vessel accessed nor by type of catheter. However, right-sided catheters had a longer indwell time of 117 + 159 days compared to left-sided catheters, 87 + 124 days (p =0.008). There was no significant difference in the indwell duration of first catheter in comparison to all subsequent placements. There was also no difference in complications whether the catheter was exchanged over the wire or placed de novo. Nor were complication rates different among M.D. versus P.A. conducted procedures. We conclude that our rates of infection are similar to other institutions and the vessels located on the right-side of the neck are preferable to left-sided vessels to increase catheter longevity. Future research is needed to better assess how rates and incidences of complications change with long standing catheter-reliance.

Thesis (M.Sc.), Memorial University of Newfoundland, Faculty of Medicine, 1998. / Restricted until June 1999. Bibliography: leaves 123-133.

published_or_final_version / Nursing Studies / Master / Master of Nursing in Advanced Practice

Today there is an increasing clinical demand and expectation of patients for biomaterials, which underscores the importance of discovering the correlations between biomaterials and biological systems, especially blood. When an artificial material makes contact with blood, the first event is a rapid adsorption of plasma protein on the material surface, on top of which the innate immune system is triggered, with potentially detrimental consequences. The work presented in this thesis, reported in four papers, was designed to investigate complications associated with (a) biomaterial-induced immune systems, including activation mechanisms and crosstalk between cascades on the biomaterial surface, and with (b) clinical investigations. In Paper I and Paper II, a series of studies led to the development of a direct prediction of the subsequent biological events based on the pattern of initially bound proteins. A reciprocal relationship was demonstrated between activation of the contact system and the complement system when they were induced on artificial material surfaces. Based on these studies, a robust and simple method for biocompatibility testing was proposed and validated, yielding high specificity and sensitivity when compared to today’s gold standard. Paper III investigated biomaterial-induced activation of complement and leukocytes in dialysis treatment-related conditions. The results suggested that citrate is more biocompatible than the conventionally used acetate. This reduction in activation could be further enhanced with higher citrate concentrations, suggesting that dialysis fluid containing citrate is a promising alternative to acetate dialysis fluid. Paper IV investigated complement initiation mechanisms with clinical implications. An experimental system was set up to revisit the initiation of the complement alternative pathway, and correlations were found between chaotropic or nucleophilic agents and iC3 generation under physiologically relevant conditions. A clinical study of hepatic encephalopathy patients indicated a direct correlation between elevated plasma ammonia and iC3 formation, as well as with complement activation in vivo.  Taken together, these studies have provided a model for a robust biomaterial test and have investigated biomaterial-induced complications in the fluid phase in clinically related conditions; furthermore, the basic mechanisms of complement activation have been dissected in relation to disease symptoms. Keywords: Complement system, contact system, blood, biomaterials, biocompatibility, in vitro screening, iC3, dialysis

INTRODUCTION: National obesity rates are leading to higher rates of Type 2 Diabetes, increasing the number of people at risk of invasive infections with Methicillin Resistant Staphylococcus aureus (iMRSA) upon onset of ESRD and hemodialysis. However, an association between adiposity and risk of iMRSA has not been researched. AIM: The purpose of this study is to describe the epidemiological characteristics of an iMRSA cohort in the Atlanta metro area between 2005-2008; to examine BMI-related health outcomes within the cohort; and to compare proportions of BMI categories in this cohort to BRFSS data. METHODS: Surveillance data collected by the CDC EIP program on iMRSA in Atlanta, Georgia was used. BMI was calculated for each eligible case. Statistical analysis was carried out in SPSS. Univariate and multivariate binary logistic regression analysis was performed on select variables. A p-value of < 0.05 and a 95% confidence interval (CI) were used to determine significance. BRFSS BMI data for Georgia was compared to the study population. RESULTS: Overweight and obese cases were more likely to be diagnosed with diabetes by regression analysis. Cases with diabetes were at greater odds of having undergone dialysis within the previous year (univariate OR=2.3, p=0.000; multivariate OR=2.5, p=0.000). The proportion of iMRSA patients with diabetes is much greater (42.8%) than in the general population of the United States (7.8-10.7%). DISCUSSION: The results indicate that there may be a higher risk for iMRSA in overweight and obese individuals, particularly if other adiposity-related health problems are present.

Nurses at a haemodialysis clinic are required to handle complex technological equipment in a stressful environment, with the patients’ lives at risk. A training needs analysis (TNA) that was made at Karolinska University Hospital Huddinge in 2010 identifies the nurses’ need to practice alarm situations in the safe environment of a computer-based training simulator. This project builds on the conclusions of the TNA and the aim is to evaluate the concept of a training simulator by developing and evaluating a prototype program. The simulation model used is the prototype is based on a problem solving approach with virtual patient scenarios. During the entire development process continuous input has been gathered from nurses who work with dialysis. The project was completed by structured user test focusing on evaluating the usability and realism of the prototype. The conclusion of the project is that nurses working with dialysis need to practice alarm situations and that a training simulator could meet this need. The report is written in English.

This thesis investigates the role of Canadians in the international trade in human organs and the factors influencing patient decision making, assuming that patients make decisions regarding the management of their illness in a complex social, cultural, political and economic nexus. It engages a broad theoretical question of whether Canadians uphold values consistent with a commitment to consumerism, commodifying organs as needed and afforded, or altruism, supportive of voluntary organ donation systems. Semi-structured interviews were conducted with hemodialysis patients and their care givers in a southern Ontario hospital. Based on this analysis, Canadians appear to fall somewhere in the middle of the consumer-altruist divide. The dominant sentiment among participants was that Canadians ought not to be commodified, but the organs of foreign others in places removed from the Canadian value system hold potential, and provide opportunities for participating in a market when the supply of organs falls short of demand.

Our epidemiology research found that the incident and prevalent rates for Diabetes mellitus (DM) and Diabetic End Stage Renal Disease (DM-ESRD) were at rise in Saskatchewan between year 1980 and 2005. Combining concerns regarding the rising trends reported by research studies with the concerns of the significant health and financial burden imposed by DM-ESRD on individuals and societies, we sought to project the number of DM-ESRD patients in Saskatchewan up to year 2025 with the cost required for caring for those patients. An agent-based model (ABM) is developed to simulate DM to ESRD progression, treatments for DM-ESRD patients, and the assessments and waiting list processes preparing patients for kidney transplants. The model parameters were estimated from a wide variety of data sources. The agent based modeling approach is chosen for projections regarding the DM-ESRD situation in Saskatchewan because of its advantage in capturing heterogeneities of individual patients, ability to retain biographical information on patients, capacity to capture time-varying competing risks, better presentations features and easy integration with existing models built in either agent based or System Dynamic methods. The approach was also attractive due to its flexibility for future expansion to represent social networks. The model projects the incident and prevalent case count, cost, and person years lived for the DM-ESRD population in Saskatchewan between year 1980 and 2025. The projections captured the great challenges brought by the fast growing number of DM-ESRD patients and substantial cost associated with managing the disease. In addition to producing projection results, the research presented here demonstrates how the model can be used by policy makers to experiment and evaluate different policy/interventions in a safe context. By capturing both the individual level records and population level statistics, the model provide a wealth of data for detailed analysis, which can help health policy makers gain insights in the current and future diabetic-ESRD situation in the province, aiding in resources planning for managing the fast-growing ESRD population and the growing need for dialysis services.