Made available in DSpace on 2014-06-11T19:32:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-09-25Bitstream added on 2014-06-13T21:03:37Z : No. of bitstreams: 1 000739125.pdf: 8253955 bytes, checksum: 0020aaeb461490f20e4ed55bb6a089f5 (MD5) / Comparar os efeitos agudos do óxido nítrico inalatório (Noi) sobre a oxigenação durante ventilação oscilatória de alta frequência (VAF) e ventilação mecânica convencional (VMC) em crianças com insuficiência respiratória hipoxêmica aguda (IRHA). Crianças com IRHA, com idade entre 1 mês e 14 anos, em VMC com pressão expiratória final positiva (PEEP) maior ou igual a 10cmH2O foram aleatorizadas para VMC (GVMC, n=14) ou VAF (GVAF, n=14), em estudo randomizado e cruzado. Foram registrados índices de oxigenação e variáveis hemodinâmicas à inclusão (Tind), 1 hora após iniciar VMC (T0) e a cada 4h (T4...T24). A relação PaO2/FiO2 aumentou significantemente depois de 4 horas comparada com a inclusão em ambos os grupos [(GVMC- Tind: 111,95 ± 37 < T4h: 143,88 ± 47,5mmHg, p<0,05; GVAF- Tind: 123,76 ± 33 < T4h: 194,61 ± 62,42mmHg, p<0,05)], sem diferença estatística entre eles. Em T8h, a relação PaO2/FiO2 foi maior no GVAF comparado com GVMC (GVAF: 227,9 ± 80,7 > GVMC: 171,21 ± 52,9mmHg, p < 0,05). A FiO2 pode ser reduzida após 4h no GVAF ( GVAF- T4h: 0,53 ± 0,09 < Tind: 0,64 ± 0,2; P < 0,05), mas somente após 8 horas no GVMC. Comparando os grupos em T8h, observou-se que a diminuição da FiO2 foi maior para o GVAF (GVAF: 0,47 ± 0,06 < GVMC: 0,58 ± 0,1; p < 0,05). Tanto a VAF como VMC, associadas com a administração precoce de NOi, melhoram a oxigenação. A VAF possibilita redução da FiO2 e aumento da relação PaO2/FiO2 mais precoces quando comparada com VMC, em 8h. Entretanto, ao final de 24h de observação, não houve diferença significante na melhora clínica devido a aplicação da VAF associada com NOi quando comparada com VMC associada com o gás. Nossos resultados precisam ser confirmados por uma base mais ampla de casos em estudo randomizado / To compare the acute oxygenation effects of high-frequency oscillatory ventilation (HFOV) plus inhaled nitric oxide (iNO) with conventional mechanical ventilation (CMV) plus iNO in acute hypoxemic respiratory failure (AHRF) children. Children with AHRF, aged between 1 month and 14 years under CMV with PEEP ≥ 10 cmH2O were randomly assigned to CMV (CMVG, n = 14) or HFOV (HFVG, n = 14) in a crossover design. Oxygenation indexes and hemodynamic variables were recorded at enrollment (Tind), 1 hr after CMV start (T0) and then every 4 hr (T4h, etc.). PaO2/FiO2 significantly increased after 4 hr compared to enrollment in both groups [(CMVG -Tind: 111.95 ± 37 < T4h: 143.88 ± 47.5 mmHg, p < 0.05; HFVG-Tind: 123.76 ± 33 < T4h:194.61± 62.42 mmHg, p < 0.05)] without statistical differences between groups. At T8h, PaO2/FiO2 was greater for HFVG compared with CMVG (HFVG: 227.9 ± 80.7 > CMVG: 171.21 ± 52.9 mmHg, p < 0.05). FiO2 could be significantly reduced after 4 hr for HFVG (HFVG-T4h: 0.53 ± 0.09 < Tind: 0.64 ± 0.2; P < 0.05) but only after 8 hr for CMVG. Comparing groups at T8h, it was observed that FiO2 decrease was greater for HFVG (HFVG: 0.47 ± 0.06 < CMVG: 0.58 ± 0.1; p < 0.05). CBoth ventilatory techniques with iNO improve oxygenation. HFOV causes earlier FiO2 reduction and increased PaO2/FiO2 ratio compared to CMV at 8 hr. However, at the end of the protocol, there was no significant difference and no clinical improvement derived from the application of both ventilatory strategies with iNO. It is not possible to say what would have happened if a different conventional ventilatory mode had been used, given the fact that our study has a limited number of patients included in each group

M.Cur. / Neonates born with respiratory distress require supplementary oxygen. In some cases it is necessary to ventilate these neonates in order to obtain adequate tissue oxygenation. Due to the potential complications of mechanical ventilation it is necessary to extubate the neonate as soon as possible after intubation and administer supplementary oxygen by an alternate method. Any form of oxygen therapy carries the risk of oxygen toxicity. It is therefore essential that the method of oxygen therapy opted for after extubation will result in the infant being weaned in the shortest time possible. In the two NICUs from which the sample was taken for this study, neonates are currently extubated and placed either in a head box, on nasal CP AP or on a nasal cannula, these being the methods used to administer oxygen to a neonate. The decision regarding the method of choice is currently directed by customary practices rather than physiological variables as indicators/criteria of effectiveness. The questions that arise from the research problem are as follows: • Which physiological variables should be considered when faced with the decision regarding the method of oxygen therapy to initiate after extubation of a neonate? • Are there any differences in the effectiveness of the two methods of oxygen therapy, namely headbox and nasal cannula, after extubation of a neonate? The purpose of this study was to compare two methods of oxygen therapy, after extubation of the neonate with respiratory distress syndrome, in an attempt to formulate guidelines; based on physiological variables as criteria/indicators of effectiveness. After analyzing the data, as described in Chapter 4, it became evident that it would not be possible to formulate guidelines. Therefore only a comparison was done between the two methods of oxygen therapy (headbox and nasal cannula,) based on both biographical and physiological variables as criteria/indicators, to determine whether there were any significant differences in the effectiveness of the two methods after extubation of the neonate.

Mechanical ventilation (MV) is one of the most frequently used treatment modalities in the intensive care unit (ICU) (Burns, 2005:14). Up to 90% of critically ill patients in ICUs globally are connected to a mechanical ventilator. Although mechanical ventilation is a lifesaving intervention, it is expensive and is associated with diverse complications (Mclean, Jensen, Schroeder, Gibney & Skjodt, 2006: 299). Ventilator-associated pneumonia (VAP) accounts for 25% of all infections in ICU, with global crude mortality figures estimated at 20-70% (Craven, 2006:251). Minimising the time that a patient is connected to a mechanical ventilator to the absolute minimum can have considerable benefits in terms of decreased mortality and morbidity, as well as a decreased length of ICU stay and lower hospital costs. Critically ill patients therefore need to be weaned from the mechanical ventilator as soon as their condition that warranted the need for mechanical ventilation is stabilized. The process of weaning the critically ill patient from mechanical ventilation constitutes a significant proportion of total ventilator time. As professional nurses attend to the mechanically ventilated patient 24 hours a day, they have a vital role to play in the collaborative management of the patient requiring weaning from mechanical ventilation. The objectives of this study were to explore and describe the professional nurses’ knowledge regarding weaning the critically ill patient from mechanical ventilation. Based on the results, recommendations in the form of a protocol were made in order to improve the professional nurses’ knowledge and enhance the care of the mechanically ventilated patient. A quantitative design, which was exploratory, descriptive and contextual in nature, was utilised for the study. The data collection instrument of choice was a self-administered questionnaire. Convenience, non-probability sampling was the sampling method chosen for the purpose of this study. Collected data were analysed with the assistance of a statistician using descriptive and inferential statistics. Results were displayed in the form of graphs and tables. The results obtained in the study, combined with data from the literature review, were used to develop recommendations to enhance vi professional nurses’ knowledge regarding weaning the critically ill patient from mechanical ventilation. The recommendations were presented in the form of a protocol based on the available evidence. Ethical principles as they relate to conducting research were adhered to throughout the study.

Background: Spinal Cord Injuries (SCIs) are traumatic, life-changing injuries that can affect every aspect of an individual's life and can lead to death if not treated timeously and appropriately. Respiratory complications occur frequently after the SCI and are the leading cause of mortality and morbidity. Respiratory complications are predictable based on the neurological level of impairment of the spinal cord lesion; the higher the neurological injury, the more severe the respiratory complication. Changes in pulmonary function, poor cough, hypersecretion, immobility and bronchospasm all contribute to the development of respiratory complications. If the patient is unable to protect his/her airway or if respiratory failure occurs, mechanical ventilation is often required. Many patients require prolonged ventilation and subsequently need to go for tracheostomies. The critical care nurse plays an important role in the early identification of complications and can, therefore, act to limit and prevent these complications, which may be a direct result from the injury or treatment modality such as mechanical ventilation. Respiratory management has been promoted in preventing and treating respiratory complications and is associated with better prognosis in the SCI patient. Design and method: The research study aims to explore and describe existing literature and to make recommendations for the respiratory management of a mechanically ventilated spinal cord injured patient in a critical care unit (CCU). A systematic review was undertaken with clear inclusion and exclusion criteria. Ethical principles were maintained throughout the study. The quality of the study was ensured by critically appraising data that was utilized in the systematic review. It is envisaged that the results from this systematic review will improve the respiratory management of the SCI patient and prevent any variations in practice. Results: Were presented under the following themes: priorities of care for the SCI patient in the acute phase, during the critical care phase and preventative care. Conclusion: The SCI patient regardless of the neurological level or completeness of injury should be admitted to the CCU for intensive ventilatory, cardiopulmonary support and hemodynamic monitoring in order to detect and prevent respiratory complications. The use of larger tidal volumes is associated with improved comfort and less dyspnea however if a patient has acute lung injury or ARDS the use of low tidal volumes 6ml/kg is recommended. Prevention and early identification of respiratory complications is associated with improved outcomes for the SCI patient.

Thesis (MScEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Patients in critical care with lung injuries need to be assisted with regards to breathing function, but current methods are not applicable for all situations. The most common method, Extracorporeal Membrane Oxygenation (ECMO) is an expensive procedure and requires trained staff to operate the equipment at all times. Lung injury may lead to the inability of the lungs to be perfused and the blood oxygenated by tracheal intubation, whereas mechanical ventilators can injure the lungs further. Especially at risk are preterm neonates, where congenital disorders or complications during birth render ECMO the only viable option. Respiratory Assist Catheters (RACs) could be used as an alternative because they do not place extra stress on the lungs, are easy to implement, cost-effective and are available for immediate use in clinical settings or in first aid situations. The development of such a device requires knowledge of possible oxygenation methods as well as the risks involved in implementing such a device. The possibility of oxygenating the blood via microbubbles by means of a RAC is promising due to the high gas transfer rates common in bubble oxygenators. It is the aim of this study to develop a prototype that could function as a RAC and to evaluate the feasibility of oxygenation by using microbubbles. The method used to design a prototype included selection of various materials and finalization of a design to be tested. The tests selected were in vivo tests and ex vivo tests using animal models to investigate the dissolution times of the microbubbles, as well as the physiological effects of an intravenously placed device. Measurements of oxygen saturation of the blood in arterial blood (SaO2), venous blood (SvO2) and pulmonary pressure allowed the oxygen transfer rates and risks involved to be evaluated, and also gave an indication regarding the formation dynamics of microbubbles in the blood. An in vitro test was also performed with the aim of determining the rate of dissolving of oxygen, and hence to give an indication regarding microbubble dissolution times. Mathematical simulations based on the dissolution rate of oxygen in venous blood confirmed the abovementioned results. The tests and simulations were analysed in order to evaluate the feasibility of intravenously oxygenating the blood using microbubbles. Approximate bubble dissolution times were an indicator of the feasibility of the concept and showed that very large bubble dissolution times renders intravenous bubble oxygenation unfeasible. These large dissolution times also lessen the possibility of implementing bubble oxygenation in an intravenous device. / AFRIKAANSE OPSOMMING: Pasiënte wat a.g.v. longbeserings in hoë-sorg behandel word het hulp nodig om asem te haal, maar bestaande metodes werk nie in alle omstandighede nie. Die mees algemene metode is ekstrakorporeale membraan suurstofverbinding (Extracorporeal Membrane Oxygenation (ECMO)), maar hierdie metode is duur en het voltyds opgeleide personeel nodig om dit te beheer. Longbeserings kan lei tot die onvermoë van die longe om bloed te ontvang en ook dat die bloed suurstof kry d.m.v. trageale intubasie. Meganiese ventilators kan die longe verder beskadig. Vroeggebore babas word blootgestel aan risiko’s veral waar oorerflike afwykings/steurnisse aanwesig is of komplikasies tydens geboorte en dus die EMCO die enigste lewensvatbare opsie maak. Kateters wat asemhaling aanhelp (Respiratory Assist Catheters (RACs)) kan as alternatief gebruik word aangesien dit nie ekstra spanning op die longe plaas nie, maklik is om te implementeer, koste-effektief is en beskikbaar is vir onmiddellike gebruik in kliniese omstandighede of in noodhulpsituasies. Die ontwikkeling van hierdie tipe toestel vereis kennis van moontlike suurstofverbindingsmetodes en ook die risiko’s verbonde aan die implementering van die toestel. Die moontlikheid om die bloed van suurstof te voorsien d.m.v. mikroborrels deur die RAC lyk belowend a.g.v. die hoë gasoordrag-koers wat algemeen is by borrel suurstofverbinders. Hierdie studie het ten doel om ʼn prototipe te ontwikkel wat kan dien as ʼn RAC en ook om die lewensvatbaarheid van suurstofverbinding met mikroborrels te bepaal. Die metode wat gebruik is om die prototipe te ontwerp sluit in die kies van verskeie materiale en die finalisering van die ontwerp wat getoets moet word. Die geselekteerde in vivo en ex vivo toetse is afgeneem deur gebruik te maak van dier-modelle om sodoende ondersoek in te stel na die oplossing van die mikroborrels en ook die fisiologiese gevolge van die toestel wat binne die aar geplaas is. Metings van die suurstofversadiging van bloed in slagaarbloed (SaO2), aarbloed (SvO2) en pulmonêre druk het toegelaat dat die koers en risiko’s verbonde aan suurstofoordrag geëvalueer word. Hierdie metings gee ook ’n aanduiding van die vormingsdinamika van die mikroborrels in die bloed. ’n In vitro toets is gedoen met die doel om die koers te bepaal van die oplossing van suurstof, en dus ’n aanduiding te gee van die tyd verbonde aan die oplossing van die mikroborrels. Wiskundige simulasies gebaseer op die oplossingskoers van suurstof in are het die bogenoemde toetse bevestig. Die toetse en simulasies is geanaliseer om die lewensvatbaarheid te bepaal om suurstof binne-aars te verskaf deur mikroborrels. Geskatte tye waarteen die borrels oplos is as aanduiding gebruik vir die lewensvatbaarheid van die konsep en ook die moontlike inwerkingstelling van die binne-aarse toestel.

Thesis (M.N.)--Memorial University of Newfoundland, 2004. / Bibliography: leaves 104-108.

Bag-valve mask (BVM) ventilation maintains a patient's oxygenation and ventilation until a more definitive artificial airway can be established. In the prehospital setting of a traffic collision or medical aid scene this is performed by an Emerency Medical Technician or medical first responder. Few studies have looked at the effectiveness of Bag-valve masks (BVM) or the complication rate of ventilating an unprotected airway. The purpose and goal of this study is to educate both medical first responders and basic emergency medical technicians.

The lungs are particularly vulnerable to acute, critical illness. Respiratory failure can result not only from primary lung pathology, such as pneumonia, but also as a secondary consequence of heart failure or inflammatory illness, such as sepsis or trauma. When this occurs, it is essential to support patients with mechanical ventilation while the fundamental disease process is addressed. The goal of mechanical ventilation is to ensure adequate ventilation, which involves a magnitude of gas exchange that leads to the desired blood level of carbon dioxide, and adequate oxygenation that ensures organ function. Achieving these goals is complicated by the fact that mechanical ventilation can actually cause acute lung injury, either by inflating the lungs to excessive volumes or by using excessive pressures to inflate the lungs. Thus, the challenge to mechanical ventilation is to produce the desired blood levels of carbon dioxide and oxygen without causing further acute lung injury. In this research, we develop an analysis and control synthesis framework for a pressure-limited respirator and lung mechanics system using compartment models. Specifically, a general mathematical model is developed for the dynamic behavior of a multicompartment respiratory system. Then, based on this multicompartment model, an optimal respiratory pattern is characterized using classical calculus of variations minimization techniques for inspiratory and expiratory breathing cycles. Furthermore, model predictive controller frameworks are designed to track the given optimal respiratory air flow pattern while satisfying control input amplitude and rate constrains.

An evidence-based approach to clinical practice aims to deliver appropriate care in an efficient manner to individual patients. This approach entails the integration of research evidence, clinical expertise and the interpretation of patients' needs and perspectives in making decisions about the best care modalities. The increased emphasis internationally on improved patient care and cost effectiveness in health care delivery highlighted the need for quality health services that have to be built upon the use of best evidence to inform practice and patient-care decision-making (McKenna, Ashton and Keeney, 2004:178). Critical care nursing science, a specialised branch of nursing, focusing on the care of the critically ill patient in a designated unit, is no exception to the drive to provide improved quality and cost-effective patient care. Critical care practitioners are seen to have a specialised knowledge base, specific skills in delivering advanced health care and a commitment to serve the critically ill patient. It is expected of them to be aware of new and emerging evidence about health disease processes, treatment modalities and technology used in the critical-care units. Due to the dynamic nature of a critical care unit, it is essential that every practitioner working in the unit, whether a novice professional nurse or senior unit manager, needs to be aware of the current evidence guiding their practices (Elliot, Aitken, Chaboyer, 2007:18). With reference to the critically ill patient who is connected to a mechanical ventilator, practices related to the nursing care of this group of patients, who mostly occupy the critical care units, should be based on the best evidence in order to provide cost-effective and quality care. The research study aimed to explore and describe four identified nursing care practices related to safety of a mechanically ventilated patient as performed by professional nurses in the critical care units in the Nelson Mandela Metropole. The identified nursing-care practices include: endotrachael tube placement verification, endotracheal tube cuff pressure monitoring, endotrachael tube suctioning and mechanical ventilator settings. This objective was operationalized in Stage One of the study, by using a quantitative, explorative, descriptive and contextual approach. A structured questionnaire was utilised to collect data from professional nurses working in critical care units. From the analysed data, it was decided to select the two nursing care practices that were done least according to the best recommended practice, namely endotracheal tube suctioning and endotracheal tube cuff pressure monitoring. Based on the results, systematic reviews were done respectively on the two nursing care practices. On completion of Stage One of the study, evidence-informed clinical guidelines for the two identified nursing care practices were developed. The clinical guidelines were based on the evidence found in conducting the systematic reviews. The draft clinical guidelines were reviewed by an expert panel. Feedback from the reviewers was considered to prepare the final evidence-informed clinical guidelines. Based on the clinical guidelines, two clinical algorithms were developed, which might be used at the patient's bedside and can assist in quick dissemination of the recommendations for practice. Ethical considerations were maintained throughout the study. The quality of the study was ensured in applying the principles of validity and reliability as well as performing a critical appraisal of all data collected during the systematic review. It is envisaged that the study findings be disseminated in the critical care units in the Nelson Mandela Metropole and published in peer reviewed journals.