Inaugurele rede Universiteit Maastricht. / Engelse tekst, met dankwoord in het Nederlands. Met lit. opg.

M.Sc. (Nursing), Faculty of Health Sciences, University of the Witwatersrand, 2011 / No abstract or title page on the cd

published_or_final_version / Nursing Studies / Master / Master of Nursing

No description available.

No description available.

This thesis describes the model-based development and validation of an advisor for the maintenance of artificially ventilated patients in the intensive care unit (ICU). The advisor employs fuzzy logic to represent an anaesthetist's decision making process when adjusting ventilator settings to safely maintain a patient's blood-gases and airway pressures within desired limits. Fuzzy logic was chosen for its ability to process both quantitative and qualitative data. The advisor estimates the changes in inspired O2 fraction (FI02), peak inspiratory pressure (PEEP), respiratory rate (RR), tidal volume (VT) and inspiratory time (TIN), based upon observations of the patient state and the current ventilator settings. The advisor rules only considered the ventilation of patients on volume control (VC) and pressure regulated volume control (PRVC) modes. The fuzzy rules were handcrafted using known physiological relationships and from tacit knowledge elicited during dialogue with anaesthetists. The resulting rules were validated using a computer-based model of human respiration during artificial ventilation. This model was able to simulate a wide range of patho-physiology, and using data collected from ICU it was shown that it could be matched to real clinical data to predict the patient's response to ventilator changes. Using the model, five simulated patient scenarios were constructed via discussion with an anaesthetist. These were used to test the closed-loop performance of the prototype advisor and successfully highlighted divergent behaviour in the rules. By comparing the closed-loop responses against those produced by an anaesthetist (using the patient-model), rapid rule refinement was possible. The modified advisor demonstrated better decision matching than the prototype rules, when compared against the decisions made by the anaesthetist. The modified advisor was also tested using data collected from ICU. Direct comparisons were made between the decisions given by an anaesthetist and those produced by the advisor. Good decision matching was observed in patients with well behaved physiology but soon ran into difficulties if a patients state was changing rapidly or if the patient observations contained large measurement errors.

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfillment of the requirements for the degree of Master of Medicine in Obstetrics and Gynaecology MMed (O&G) Johannesburg January 2017 / Background and objectives Pregnancy can be associated with life threatening complications of pregnancy specific disease and delivery, as well as the exacerbation of preexisting comorbid disease, which requires multidisciplinary critical care. Studies have shown that advancement in medical care and access to intensive care units have been instrumental in the global decline in maternal mortality rates, particularly in developed countries. The aim of this study was to describe the admissions to ICU of all pregnant women including those with pregnancy related complications at CHBAH tertiary hospital in South Africa. Methods The study was a retrospective review of pregnant women, including pregnancy related complications, admitted to CHBAH ICU for the year of 2012. Baseline demographic data, admission diagnosis, laboratory information and acute physiological and chronic health evaluation score (APACHE II), intervention and outcomes were recorded using ICU records and general hospital records. Descriptive statistical analysis employed. Results In 2012 there were 21765 deliveries at CHBAH with 76 pregnancy related admissions to the ICU. Complete ICU data was available in 73 women. The incidence of ICU admission at the hospital was 3.5 per 1000 deliveries. The mortality rate in this group in ICU was 8.2%. The most common indication for admission was haemorrhage (43.8%) followed by medical and surgical disorders (23.3%), then sepsis (21.9%) and hypertensive disorders of pregnancy (11%). The majority of the women (98.3%) were admitted in the postpartum period. Mechanical ventilation was required in 77% of the women, inotropic support in 29% and 59% received blood transfusion products. APACHE II scoring system overestimated the possible mortality rate giving a predicted mortality rate of 15%. Conclusion Haemorrhage was the most common indication for admission to ICU. This does not concur with previous South African studies where hypertension was the most common reason for admission followed by haemorrhage. The study showed an overall mortality concurrent with some first world studies and significantly lower than cited South African studies. / MT2017

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Medicine in the branch of Paediatrics. Johannesburg, 2015. / Background: Organisms causing neonatal sepsis differ in different regions and also change with time in the same area. The antibiotic susceptibility of microorganisms also changes with time, with emergence of multidrug resistant organisms. A periodic survey of the causes of sepsis and their antibiotic sensitivity patterns is essential in the design of effective infection control programs and in guiding empiric antibiotic therapy. Aim: To evaluate the epidemiology of culture-proven neonatal sepsis and to describe the clinical characteristics of patients with neonatal sepsis at a tertiary care hospital in South Africa over a one year period. Methods: This was a retrospective descriptive study conducted in the neonatal unit at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH). Clinical and laboratory data of patients, admitted to the CMJAH neonatal unit between 1 January 2012 and 31 December 2012 with positive blood cultures were reviewed. Results: During this time there were 196 patients with blood-culture proven neonatal sepsis (NNS). This gave an incidence of 10.26 per 100 admissions. Late-onset sepsis (LOS) accounted for 83.7% of cases of NNS. Of the 196 patients with NNS, 117 (59.39%) were males. The median gestational age for patients with NNS was 30 weeks and the median birth weight was 1300g. HIV exposure was present in 30.67 % of patients. Predominant isolates were Klebsiella pneumioniae (32.20%), coagulase-negative staphylococci (23.72%) and methicillin-resistant Staphylococcus aureus (13.13%). The majority of the isolated K.pneumoniae were extended beta-lactamase-producing (ESBL) with resistance to ampicillin and gentamicin. Conclusion: Neonatal sepsis is an important cause of mortality at CMJAH neonatal unit. Compared to previous audits in the unit, the incidence of NNS in the unit is on the increase while mortality from NNS has remained relatively constant. LOS was more common than EOS at CMJAH. A changing pattern of bacteria isolated has been observed. Gramnegative microorganisms comprised the majority of the neonatal sepsis, with ESBL Klebsiella pneumoniae and A. baumannii being the most prevalent. Coagulase negative staphylococcus remains an important cause of NNS, and is the most prevalent grampositive organism isolated. Resistance to the first-line antibiotic regimen for both EOS and LOS is significant. Due to the changing pattern of bacteria isolated and changing patterns in antibiotic sensitivity, recommendations are made regarding early empiric antibiotic therapy.

The cerebral damage after cardiac arrest is thought to arise both from the ischemia during the cardiac arrest but also during reperfusion. It is the degree of cerebral damage which determines the outcome in patients. This thesis focuses on the cerebral damage after cardiac arrest. In two animal studies, positron emission tomography (PET) was used to measure cerebral blood flow, oxygen metabolism and oxygen extraction in the brain. After restoration of spontaneous circulation (ROSC) from five or ten minutes of cardiac arrest there was an immediate hyperperfusion, followed by a hypoperfusion which was most evident in the cortex. The oxygen metabolism decreased after ROSC with the lowest values in the cortex. The oxygen extraction was high at 60 minutes after ROSC, indicating an ischemic situation. After ten minutes of cardiac arrest, there was a hyperperfusion in the cerebellum. In 31 patients resuscitated after cardiac arrest and treated with hypothermia for 24 hours, blood samples were collected from admission until 108 hours after ROSC. The samples were analyzed for different biomarkers in order to test the predictive value of the biomarkers. The patients were assessed regarding their neurological outcome at discharge from the intensive care unit and after six months. Brain derived neurotrophic factor (BDNF) and glial fibrillary acidic protein (GFAP) was not associated with outcome. Neuron specific enolase (NSE) concentrations were higher among those with a poor outcome with a sensitivity of 57% and a specificity of 93% when sampled 96 hours after ROSC. S-100B was very accurate in predicting outcome; after 24 hours after ROSC it predicted a poor outcome with a sensitivity of 87% and a specificity of 100%. Tau protein predicted a poor outcome after 96 hours after ROSC with a sensitivity of 71% and a specificity of 93%.

N/A (long introduction)