Browsing by Author "James, Michael Frank Mansel"

Now showing 1 - 8 of 8
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    Capnography : principles, applications and uses in trauma and emergencies
    (2004) Wood, Darryl; James, Michael Frank Mansel
    Aims: To assess the level of knowledge and use of capnography among medical personnel in emergency departments in the Western Cape; To assess the cost effectiveness of capnography in emergency departments; To make recommendations to emergency departments in the Western Cape on capnography.
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    A comparative study of ROTEM-EXTEM results obtained from EDTA-treated whole blood samples and Sodium Citrate-treated whole blood samples in healthy volunteers
    (2016) Du Preez, Marlize; James, Michael Frank Mansel; Dyer, Robert A
    Background: A number of anticoagulants are available in clinical use to preserve blood samples in liquid form until a suitable time for laboratory testing. Rotational thromboelastography is usually performed on a blood sample that has been anticoagulated with sodium citrate and then recalcified immediately prior to testing. In our institution we have had shortages of citrated Vacutainer® sample tubes. The use of a single in vitro anticoagulant promises to cut costs, simplify laboratory processes as well as limit the amount of blood drawn from patients. This together with the known problems with using citrate as an anticoagulant for viscoelastic testing (VET) prompted us to investigate the suitability of EDTA as anticoagulant for VET. Method: Blood samples from 20 healthy volunteers were divided into citrated and EDTA Vacutainer® tubes. A ROTEM EXTEM® assay was performed on each sample in both groups following the manufacturer's guidelines. Clotting time (CT), clot formation time (CFT), alpha angle (α-angle) and maximum clot firmness (MCF) results were compared. Ionised calcium concentrations were measured on each sample before and after recalcification with CaCl2 to determine if there was a significant difference in post - recalcification ionised calcium concentrations between the groups. Results: The results from the two groups were treated by Bland-Altman analysis. Apart from MCF values there was significant bias between all parameters measured in the two groups. The limits of agreement for all parameters apart from MCF were unacceptable. Conclusion: We found that ROTEM EXTEM® results from EDTA samples were not comparable to or interchangeable with those from citrated samples. The difference in results is not due to differences in ionised calcium concentration levels in the samples post-recalcification as the ionised calcium concentrations in both groups post-recalcification were adequate for coagulation. EDTA samples did show superior consistency in all parameters and may be a suitable alternative for sample preservation for VET if reference ranges can be established.
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    A cost comparison of spontaneously ventilated patients: the universal anaesthesia machine as a possible cost effective alternative
    (2015) Van Rensburg, G P; Nieuwveld, Robert; James, Michael Frank Mansel
    Background: A new appreciation of relevant risks, as well as the increased availability of technologies that facilitate the use of regional techniques, have increased the number of patients that are allowed to breathe spontaneously during their procedures. The ever-growing caseload of surgical patients in resource poor environments demands an anaesthetic service and equipment capable of meeting with these demands. Methods: Patients were recruited to receive their general anaesthesia by means of either the Universal Anaesthesia Machine (UAM) or the standard plenum system available. Anaesthesia was administered according to a protocol and the consumption of electricity, carrier gases, volatile hypnotic agent and carbon dioxide absorbent was measured. The cost per minute was then calculated for each device respectively. Results: Our study recruited 50 patients (25 into each group) across several surgical specialties. We found that when calculated as a total South African Rand (ZAR) per minute cost (for our centre) the UAM was statistically significantly more expensive (R 0.974/min vs. R 0.459/min, p < 0,00001). We were able to derive equations to predict the cost consumption of the respective devices, allowing the use of this data in a wide array of clinical settings. Conclusion: Whilst our finding is by no means surprising, it allowed us to produce formulae by which individual centres can calculate the implications of each option using the specific costs of the various consumables available to them.
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    The development of an in vivo nerve-muscle model in the rat : and an experiment "The interaction between rocuronium and thiopentone" to test the validity of the model
    (2005) Rous, Stephen Alexander; James, Michael Frank Mansel
    Experimentation involving small animals has, over the years, been of major importance in the development of our current understanding of nerve - muscle physiology. This dissertation describes the development of an in vivo model of the rat nerve interface at the Faculty of Health Sciences at the University of Cape Town. Such a model was not previously available to the faculty. The development was the result of collaboration between the Departments of Anaesthesia and Human Biology.
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    Haemodilution and coagulation
    (2003) Ruttmann, Thomas Gotthard; James, Michael Frank Mansel
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    Haemodynamic consequences of Spinal Anaesthesia for non-emergency Caesarean section
    (2009) Dyer, Robert A; James, Michael Frank Mansel
    Single shot spinal anaesthesia for caesarean section is currently accepted as the favoured method in the absence of contraindications, for reasons of safety and comfort. Firstly, there is an increased risk of failed intubation associated with general anaesthesia. Secondly, spinal anaesthesia, if practiced correctly, allows for a superior experience of the delivery and improved bonding with the infant. Maternal haemodynamic stability is desirable both for maternal and neonatal safety, and to diminish maternal side-effects such as nausea and vomiting. Therefore, after an extensive literature review, clinically relevant aspects of spinal anaesthesia were studied, with a view to contributing to knowledge which could improve safety and outcome. The central themes explored in this thesis were fluid management during spinal anaesthesia for caesarean section in healthy parturients, the haemodynamic effects of the vasoactive agents ephedrine, phenylephrine and oxytocin during spinal anaesthesia for caesarean section in healthy patients and in patients with preeclampsia, and short term neonatal outcome after spinal anaesthesia in patients with severe preeclampsia. Research methodology included non-invasive measures as well as the use of a pulse wave form analysis monitor to measure maternal cardiac output. A validation study was performed comparing this method with thermodilution in patients with postpartum complications of preeclampsia. Abstract viii The results of these studies showed that: The pulse wave form monitor employed showed acceptable limits of agreement with the thermodilution method. Crystalloid coload was associated with lower vasopressor requirements than conventional preload. Spinal anaesthesia was associated with afterload reduction, which was more pronounced in healthy patients than in preeclamptics. Ephedrine maintained or increased, and phenylephrine reduced maternal cardiac output in healthy patients. Oxytocin was associated with transient haemodynamic instability in healthy and preeclamptic patients, which was obtunded by phenylephrine in the healthy population. Spinal anaesthesia for caesarean section was associated with a greater umbilical arterial base deficit than general anaesthesia in patients with preeclampsia. Overall, these studies should contribute to improved knowledge of haemodynamic responses during spinal anaesthesia for caesarean section, and ultimately to improved maternal morbidity and mortality.
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    Prehospital endotracheal intubation practices by paramedics in the provincial ambulance service of the Western Cape province of South Africa
    (2006) Roos, John; James, Michael Frank Mansel
    It is well-established that endotracheal intubation in the field is associated with a considerably greater degree of difficulty, and a much higher complication and failure rate than intubation undertaken in the operating-theatre environment. The reasons for this are many-fold, have been quantified and discussed in detail. This study assesses the difficulties encounteed by paramedics in the field, by identifying factors contributing to difficult and failed intubation, by quantifying the incidence of difficult and failed intubations, by assessing and describing the incidence of complications and adverse outcomes, and by assessing the impact of the procedure on patient care. This dissertation includes a comprehensive international literature review of studies related to prehospital endotracheal intubation, and discusses and compares these published findings to the results obtained from this study. Furthermore, this study provides feedback to paramedics, paramedic-educators and managers, by offering a comprehensive strategy for improvement in the procedure of field intubation, with a view to increased safety, ease of execution, and improved patient outcome.