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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A minimum cost and risk mitigation approach for blood collection

Zeng, Chenxi 27 May 2016 (has links)
Due to the limited supply and perishable nature of blood products, effective management of blood collection is critical for high quality healthcare delivery. Whole blood is typically collected over a 6 to 8 hour collection window from volunteer donors at sites, e.g., schools, universities, churches, companies, that are a significant distance from the blood products processing facility and then transported from collection site to processing facility by a blood mobile. The length of time between collecting whole blood and processing it into cryoprecipitate ("cryo"), a critical blood product for controlling massive hemorrhaging, cannot take longer than 8 hours (the 8 hour collection to completion constraint), while the collection to completion constraint for other blood products is 24 hours. In order to meet the collection to completion constraint for cryo, it is often necessary to have a "mid-drive collection"; i.e., for a vehicle other than the blood mobile to pickup and transport, at extra cost, whole blood units collected during early in the collection window to the processing facility. In this dissertation, we develop analytical models to: (1) analyze which collection sites should be designated as cryo collection sites to minimize total collection costs while satisfying the collection to completion constraint and meeting the weekly production target (the non-split case), (2) analyze the impact of changing the current process to allow collection windows to be split into two intervals and then determining which intervals should be designated as cryo collection intervals (the split case), (3) insure that the weekly production target is met with high probability. These problems lead to MDP models with large state and action spaces and constraints to guarantee that the weekly production target is met with high probability. These models are computationally intractable for problems having state and action spaces of realistic cardinality. We consider two approaches to guarantee that the weekly production target is met with high probability: (1) a penalty function approach and (2) a chance constraint approach. For the MDP with penalty function approach, we first relax a constraint that significantly reduces the cardinality of the state space and provides a lower bound on the optimal expected weekly cost of collecting whole blood for cryo while satisfying the collection to completion constraint. We then present an action elimination procedure that coupled with the constraint relaxation leads to a computationally tractable lower bound. We then develop several heuristics that generate sub-optimal policies and provide an analytical description of the difference between the upper and lower bounds in order to determine the quality of the heuristics. For the multiple decision epoch MDP model with chance constraint approach, we first note by example that a straightforward application of dynamic programming can lead to a sub-optimal policy. We then restrict the model to a single decision epoch. We then use a computationally tractable rolling horizon procedure for policy determination. We also present a simple greedy heuristic (another rolling horizon decision making procedure) based on ranking the collection intervals by mid-drive pickup cost per unit of expected cryo collected, which results in a competitive sub-optimal solution and leads to the development of a practical decision support tool (DST). Using real data from the American Red Cross (ARC), we estimate that this DST reduces total cost by about 30% for the non-split case and 70% for the split case, compared to the current practice. Initial implementation of the DST at the ARC Southern regional manufacturing and service center supports our estimates and indicates the potential for significant improvement in current practice.
2

Cryoprecipitate Transfusion: Assessing Appropriateness and Dosing in Trauma

Nascimento, Bartolomeu Jr. 15 August 2012 (has links)
Cryoprecipitate is commonly used outside guidelines. In trauma, the appropriate cryoprecipitate dose and its impact on plasma fibrinogen levels are unclear. This retrospective study aims to evaluate: (1) the appropriateness of cryoprecipitate transfusion in trauma; and (2) the plasma fibrinogen response to cryoprecipitate transfusion during massive transfusion in trauma. Fibrinogen levels of < 1.0 g/L within 2 and 6 hours of cryoprecipitate transfusion were used for assessing appropriateness. Out of 394 events, 238 (60%) and 259 (66%) were considered appropriate using 2 and 6 hour criteria, respectively. A dose of 8.7 (±1.7) units caused a mean increase in fibrinogen levels of 0.55 (±0.24) g/L, or 0.06g/L per unit. In our hospital, where transfusion guidelines and policies for rapid blood product and laboratory turnaround times exist, it is possible to achieve high rates of appropriateness for cryoprecipitate transfusion in trauma. The current recommended dose causes a modest increase in fibrinogen levels.
3

Cryoprecipitate Transfusion: Assessing Appropriateness and Dosing in Trauma

Nascimento, Bartolomeu Jr. 15 August 2012 (has links)
Cryoprecipitate is commonly used outside guidelines. In trauma, the appropriate cryoprecipitate dose and its impact on plasma fibrinogen levels are unclear. This retrospective study aims to evaluate: (1) the appropriateness of cryoprecipitate transfusion in trauma; and (2) the plasma fibrinogen response to cryoprecipitate transfusion during massive transfusion in trauma. Fibrinogen levels of < 1.0 g/L within 2 and 6 hours of cryoprecipitate transfusion were used for assessing appropriateness. Out of 394 events, 238 (60%) and 259 (66%) were considered appropriate using 2 and 6 hour criteria, respectively. A dose of 8.7 (±1.7) units caused a mean increase in fibrinogen levels of 0.55 (±0.24) g/L, or 0.06g/L per unit. In our hospital, where transfusion guidelines and policies for rapid blood product and laboratory turnaround times exist, it is possible to achieve high rates of appropriateness for cryoprecipitate transfusion in trauma. The current recommended dose causes a modest increase in fibrinogen levels.
4

New applications of Antrad Medical's thawing technology : Applications within the clinical and laboratory segment / Nya tillämpningar av Antrad Medicals upptiningsteknik : Klinik- och laboratorietillämpningar

Truvé, Malin, Kilegran, Johanna January 2016 (has links)
Antrad Medical has developed an ultra-fast blood plasma thawing device named UFT100. The method is based on thawing with an oscillating electrical field and unlike water baths it is a dry method. Fast and homogeneous thawing is achieved. This project investigates new possible applications where this thawing technology could be used within the clinical and laboratory segment. The aim was to identify existing thawing and heating methods for a substance that can be improved and potentially replaced with the UFT100.   Data has been collected through literature research and interviews with Antrad Medical and specialists working in Sweden. The specialists are working within the clinical and laboratory field. A number of criteria for establishment of the UFT100 were set up and used as a tool for evaluation.   The substances investigated during this project were infusion medicine, embryos, substance in a sampling tube, protein based pharmaceuticals, stem cells for transplantation and research, biobank sampling tubes, cryoprecipitate, human hepatocytes, live vaccines, API, BDS, intermediate and antibodies. Two applications within the clinical area are found probable, stem cells and cryoprecipitate. Further investigation for human hepatocytes, API, BDS, intermediate and pharmaceuticals is needed. / Antrad Medical har utvecklat en ultra-snabb blodplasmaupptinare kallad UFT100. Det är till skillnad från vattenbad en torr metod baserad på upptining med hjälp av oscillerande elektriska fält. Genom detta uppnås snabb och homogen upptining. Detta projekt undersöker nya möjliga kliniska- och laboratorietillämpningar för upptiningstekniken. Målet var att identifiera substanser vars nuvarande upptining- och uppvärmningsteknik kan förbättras och kanske ersättas med UFT100. Data har samlats in genom litteratursökning och genom intervjuer med Antrad Medical och specialister som arbetar i Sverige. Specialisterna arbetar inom kliniska områden och laboratorieverksamheter. Ett antal kriterier för etablering av UFT100 sattes upp och användes för utvärdering. Substanserna som undersöktes under projektets gång var infusionsmedicin, embryon, innehåll i ett provrör, proteinbaserade läkemedel, stamceller för transplantation och forskning, biobank-provrör, kryoprecipitat, humana hepatocyter, levande vaccin, aktiva substanser, läkemedelssubstanser, intermediat och antikroppar. Två tillämpningar inom det kliniska området ses som möjliga, stamceller och kryoprecipitat. Humana hepatocyter, aktiva substanser, läkemedelssubstanser och intermediat behöver undersökas vidare.

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