M.Sc. (Nursing), Faculty of Health Sciences, University of the Witwatersrand, 2009

Background: Delirium is common in critically ill trauma patients, yet there is no evidence-based standard of care sedation agent for this population. Objective: This thesis aims to expand knowledge around dexmedetomidine, a sedative that has demonstrated potential superiority in other clinical patient populations. Methods: We conducted a systematic review and network meta-analysis to compare the effectiveness of sedatives on delirium and associated patient outcomes. We conducted a health records review of sedated trauma patients at The Ottawa Hospital. We derived a simple mathematical model to demonstrate potential impact of dexmedetomidine on resources. Results: There was no statistical difference between sedatives in preventing delirium. Approximately 79% of critical trauma patients were sedated with propofol, 18% with propofol and dexmedetomidine, and 3 with dexmedetomidine. Increasing the proportion of patients receiving propofol with adjunct dexmedetomidine could improve the number of freed ICU bed-days. Conclusion: Dexmedetomidine could have potential benefits in improving outcomes for critically ill trauma patients.

No description available.

To prevent disease outbreaks and increase competitiveness of U.S. shrimp products, U.S. aquaculture researchers have developed super-intensive, bio-secure, recirculating shrimp production systems since the early 1990s. The general objective of this research is to determine an optimal production strategy to maximize the net revenue for the system. An inventory optimization model was built to determine the optimal harvesting week, shrimp size, and number of crops per year for experimental trials conducted at the Gulf Coast Research Laboratory (Ocean Springs, MS), the Waddell Maricultural Center (Bluffton, SC), and the Oceanic Institute (Oahu, HI). Survival rate and selling price sensitivity analyses were conducted to see their impact on the system¡¯s net revenue. The optimal harvesting week solved by this model is determined by shrimp growth and feed functions. Producer selling price and survival rate can affect the value of net revenue, but do not impact the optimal harvesting week. Shrimp producers can use the developed inventory optimization model and results to efficiently manage their operations.

No description available.

No description available.

Memory capacity, bandwidth, and energy all continue to present hurdles in the quest for efficient, high-speed computing. Recognition, mining, and synthesis (RMS) applications in particular are limited by the efficiency of the memory subsystem due to their large datasets and need to frequently access memory. RMS applications, such as those in machine learning, deliver intelligent analysis and decision making through their ability to learn, identify, and create complex data models. To meet growing demand for RMS application deployment in battery constrained devices, such as mobile and Internet-of-Things, designers will need novel techniques to improve system energy consumption and performance. Fortunately, many RMS applications demonstrate inherent error resilience, a property that allows them to produce acceptable outputs even when data used in computation contain errors. Approximate storage techniques across circuits, architectures, and algorithms exploit this property to improve the energy consumption and performance of the memory subsystem through quality-energy scaling. This thesis reviews state of the art techniques in approximate storage and presents our own contribution that uses lossy compression to reduce the storage cost of media data. / MS / Computer memory systems present challenges in the quest for more powerful overall computing systems. Computer applications with the ability to learn from large sets of data in particular are limited because they need to frequently access the memory system. These applications are capable of intelligent analysis and decision making due to their ability to learn, identify, and create complex data models. To meet growing demand for intelligent applications in smartphones and other Internet connected devices, designers will need novel techniques to improve energy consumption and performance. Fortunately, many intelligent applications are naturally resistant to errors, which means they can produce acceptable outputs even when there are errors in inputs or computation. Approximate storage techniques across computer hardware and software exploit this error resistance to improve the energy consumption and performance of computer memory by purposefully reducing data precision. This thesis reviews state of the art techniques in approximate storage and presents our own contribution that uses lossy compression to reduce the storage cost of media data.

Background: When life-saving interventions are not compatible with a meaningful and dignified life for a patient in the intensive care unit, decisions are made to withdraw life-sustaining treatment, allowing for the possibility of organ donation. There are clear laws and guidelines for the process of donation. Previous research highlights the complex work of intensive care nurses, involving the care of both potential organ donors and relatives. Aim: The aim was to describe intensive care nurses' experiences of nursing care during the process of organ donation. Method: A qualitative interview study with 12 intensive care nurses. Content analysis was conducted. Results: The analysis resulted in three categories: The complex nursing care, The meaningful nursing care and Meeting the relatives in the donation process and eight subcategories emerged. Conclusion: Intensive care nurses experienced nursing care in the donation process as meaningful and as an opportunity to contribute to another person's continued life. However, nursing care was also perceived as challenging and time-consuming, both in relation to the donor and relatives. Nurses described facilitating factors such as knowledge and education about the donation process, as well as the importance of the team. A significant part of nursing care involved supporting and informing relatives. Key words: Intensive care nurses, interview study, nursing care, organ donation.

No / Improved survival in patients with hematological malignancy (HM) admitted to the intensive care unit (ICU) has largely been reported in uncontrolled cohorts from single academic institutions. We compared hospital mortality between 147 patients with HM and 147 general medical admissions to five non-specialist ICUs. The proportion of patients surviving to hospital discharge was significantly worse in patients with HM (27% vs. 56%; p < 0.001). Six-month and 1-year survival in patients with HM was 21% and 18%, respectively. HM, greater age, mechanical ventilation (MV) and acute physiology and chronic health evaluation (APACHE) II score were independent predictors of poor outcome. For patients with HM, culture proven infection, age, MV and inotropes were negative predictors. Disease-specific factors including hematological diagnosis, neutropenia, remission status, prior stem cell transplant, time from diagnosis to admission and degree of prior treatment were not predictive. Overall survival of patients with HM was worse than that recently reported from specialist units.

Bibliography / Thesis (PhD ( Interdisciplinary Health))--University of Stellenbosch, 2010. / Bibliography / ENGLISH ABSTRACT: Introduction: It is increasingly being recognized that how intensive care services are delivered may have a greater impact on patient outcome than the individual therapies. Uncertainty regarding the optimal physiotherapy service provision model in a surgical intensive care unit (ICU) exists. Methodology: The aims of this study were to 1) develop an evidence-based physiotherapy protocol; 2) validate the content of the protocol; and 3) conduct an explorative intervention trial to compare usual care to the estimated effects of providing a physiotherapy service guided by an evidence-based physiotherapy protocol by a dedicated physiotherapist. A systematic review process was used to synthesize the evidence in eight subject areas. The GRADE system was used to formulate best practice recommendations and algorithm statements. Forty-two experts from a variety of disciplines were invited to participate in a Delphi process. Finally, the evidence-based physiotherapy protocol was implemented in a surgical ICU over four three-week intervention periods by a group of research therapists. The outcomes measured included ventilator time, ventilation proportions, failed extubation proportions, length of ICU and hospital stay, mortality, functional capacity, functional ability and cost (using nursing workload as proxy). Results: Fifty-three research reports in eight subject areas were identified, 23 draft best-practice recommendations and 198 algorithm statements were formulated. The draft protocol consisted of five clinical management algorithms. Fifteen international research experts and twelve national academics in the field of critical care agreed to participate in the Delphi process. Consensus was reached on the formulation of 87% (20/23) recommendations and the rating of 66% (130/198) statements. The risk of an adverse event during the protocol care intervention period was 6:1000 treatment sessions (p=0.34). Patients admitted to the unit during the protocol care intervention period were less likely to be intubated (RR 0.16 95%CI 0.07 – 0.71; RRR 0.84 NNT 5.02; p=0.005) or fail extubation (RR 0.23 95%CI 0.05 – 0.98; RRR =0.77 NNT 6.95; p=0.04). The mean difference in the daily unit TISS-28 score between the two condition periods was 1.99 95%CI 0.65 – 3.35 (p=0.04). Patients managed by the protocol tended to remain in the hospital for a shorter time after unit discharge (p=0.05). There was no difference in the time spent on the ventilator (p=0.50), mortality (p=0.52) or in the six minute walk distance (p=0.65). In addition there was no difference in the proportion of patients who reached independence in any of the Barthel Index activities measured within 48 hours of discharge from the unit. Conclusions: The use of an evidence-based physiotherapy protocol for the comprehensive physiotherapeutic management of patients in a surgical ICU was feasible and safe. The preliminary results of this study suggest that a physiotherapy service, which is guided by an evidence-based protocol and offered by a dedicated unit therapist, has the potential to lower the cost of ICU care and facilitate the functional recovery of patients after unit discharge. This information can now be considered by administrators to optimize the physiotherapy service provided in ICU. / AFRIKAANSE OPSOMMING: Inleiding: Daar word toenemend erken dat die wyse waarop dienste gelewer word, ‘n groter impak mag hê op die uitkoms van pasiënte as die spesifieke modaliteite in gebruik. Onsekerheid heers tans oor die optimale fisioterapie diens model om te volg in ‘n chirurgiese intensiewe sorg eenheid (ISE). Metodologie: The doel van hierdie projek was om 1) ‘n bewysgesteunde protokol te ontwikkel; 2) die geldigheid van die protokol te bevestig; en 3) om deur middel van ‘n eksploratiewe studie die uitkoms van pasiënte te vergelyk wanneer die fisioterapie diens gelewer word aan die hand van die bewysgesteunde protokol deur ‘n toegewyde fisioterapeut, teenoor wanneer die gewone fisioterapie diens gelewer word. Die empiriese bewyse in agt onderwerp areas is gesintetiseer na afloop van ‘n sistematiese literatuur oorsig proses. Die GRADE sisteem is gebruik om beste praktyk aanbevelings en algoritme stellings te formuleer. Twee en veertig kundige persone van verskeie disiplines is genooi om deel te neem aan die Delphi proses om die geldigheid van die protokol te bevestig. Uiteindelik is die geldige bewysgesteunde protokol oor ‘n tydperk van vier drie weke intervensie periodes deur ‘n groep navorsings terapeute in ‘n chirurgiese ISE geïmplementeer. Die tyd wat pasiënte geventileer is, die proporsie pasiënte wat geïntubeer en geherintubeer is in die tydperk, die lengte van ISE en hospitaal verblyf, mortaliteit, funksionele kapasiteit asook funksionele vaardigheid en koste (deur die verpleeg werkslading te gebruik as ‘n indikasie van koste) is gemeet. Resultate: Drie en vyftig navorsings verslae in agt onderwerp areas is geïdentifiseer, 23 konsep aanbevelings en 198 algoritme stellings is geformuleer. Die konsep protokol het uit vyf algoritmes bestaan. Vyftien internasionale en twaalf nasionale kundiges het die uitnodiging aanvaar om aan die delphi proses deel te neem. Konsensus is bereik vir die formulering van 87% (20/23) van die aanbevelings en die gradering van 66% (130/198) van die algoritme stellings. Die risiko vir ‘n ongunstige episode tydens die protokol intervensie periode was 6:1000 sessies (p=0.34). Pasiënte wat tydens die protokol intervensie periode tot die eenheid toegelaat is was minder geneig om geïntubeer te word (RR 0.16 95%CI 0.07 – 0.71; RRR 0.84 NNT 5.02; p=0.005) of om ‘n ekstubasie te faal (RR 0.23 95%CI 0.05 – 0.98; RRR =0.77 NNT 6.95; p=0.04). Die gemiddelde verskil in die daaglikse eenheid TISS-28 telling tussen die twee intervensie periodes was 1.99 95%CI 0.65 – 3.35 (p=0.04). Patiente wat tydens die protokol intervensie periode behandel is was geneig om vinniger uit die hospitaal ontslaan te word nadat hul uit die eenheid ontslaan is (p=0.05). Daar was geen verskil in die ventilasie tyd, (p=0.50) die mortaliteit (p=0.52) of die afstand wat pasiente in ses minute kon aflê binne 48 uur na ontslag uit die eenheid (p=0.65) nie. Daar was ook geen verskil in die proporsie pasiente wat onafhanklikheid bereik het in enige van die kategorieë van die Barthell Index instrument nie. Gevolgtrekking: Die gebruik van die protokol vir die omvattende hantering van pasiënte in ‘n chirurgiese eenheid is haalbaar en veilig. Die voorlopige resultate van hierdie studie dui daarop dat wanneer ‘n fisioterapie diens in ‘n chirurgiese ISE gelewer word aan die hand van ‘n bewysgesteunde protokol deur ‘n toegewyde fisioterapeut dit die potensiaal het om ISE koste te verminder en die funksionele herstel van pasiente na ontslag uit die eenheid te fasiliteer. Hierdie inligting kan nou deur administrateurs oorweeg word om ‘n optimale fisioterapie diens in ‘n chirurgiese ISE te verseker.