Rozprawy doktorskie: „Mechanical ventilators”

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Austin, Paul Nelson. "Imposed Work of Breathing and Breathing Comfort of Nonintubated Volunters Breathing with Three Portable Ventilators and a Critical Care Ventilator". University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin997382634.

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Loan, Lori A. "The relationship between ventilator inspired gas temperature and tracheal injury in neonates /". Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/7316.

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Maia, Nathalia Parente de Sousa. "A new method based on heuristic evaluation and realistic simulation for the development of mechanical ventilators centered on the user interface". Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13680.

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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior
Introduction: New human-machine interfaces have been developed to incorporate the new modes and ventilatory parameters. Multiple monitoring data and alarms are presented in graphical interfaces, which many consider still far from ideal for the primary users, healthcare professionals. Hypothesis: Noncompliance with the heuristic human machine interaction can compromise the usability of lung mechanical ventilators by users (doctors, nurses, physiotherapists) Objectives: To develop a new methodology for evaluating and implementing improvements on a ventilator interface pulmonary mechanical intensive care unit (ICU) second heuristic principles. Methods: An experimental study, using two methodologies: one centered on heuristic evaluation by an expert, and the second one focused on a comparative assessment by non-experts. Was held during the period from January 2013 to March 2014, the Laboratory of Respiratory (RespLab). The research was divided into three steps: 1st) evaluating the usability of six habilities (connect, adjust or alter ventilation modes and their parameters; adjust and react appropriately to different types of alarms, monitor respiratory mechanical parameters, and set the trigger mode non-invasive) ventilation interface for experts users; 2nd) Implementation of suggestions for improvements to the interface by a team of specialist engineers in mechanical ventilation (MV); 3rd) Comparison between interfaces (old and new), for users not experts, assessing six tasks (call, adjust the patient, adjust the volume control ventilation (VCV), measurement of mechanical, adjust the pressure control ventilation (PCV), pressure suport ventilation adjustment (PSV). The analysis of the 1st step was descriptive. The outcomes of the 3rd step were: executionÂs runtime and successes of tasks and usability score by analogic visual scale (AVS). Results: Step 1: Participants 8 professional experts. 93 problems were listed. The most violated principles: 5 (error prevention), 1 (Visibility of System Status) and 7 (Flexibility and efficiency of use). 2nd step: passed on and discussed all reports completed by experts users. Changes in the interface were performed following the suggestions and principles heuristics. 3rd step: VCV adjustment, mechanical ventilation and PSV adjustment required longer time to execute; p = 0.02 for the runtime of the task of connecting when first used, to the old interface; p = 0.02 for correct setting of PSV when first held in the new interface; p = 0.08 for the usability score, favoring the new interface. Conclusion: It was possible to develop a new methodology for evaluating and implementing improvements on a mechanical ventilator in ICU interface according to the heuristics.
IntroduÃÃo: Novas interfaces homem-mÃquina foram desenvolvidas para incorporar os novos modos ventilatÃrios e parÃmetros de ventilaÃÃo. MÃltiplos dados de monitorizaÃÃo e alarmes sÃo apresentados nas interfaces grÃficas, que muitos consideram ainda longe da ideal para os usuÃrios primÃrios, os profissionais de saÃde. HipÃtese: O nÃo atendimento aos princÃpios heurÃsticos da interface homem-mÃquina pode comprometer a usabilidade de ventiladores pulmonares por seus usuÃrios (mÃdicos, enfermeiros, fisioterapeutas) Objetivos: Desenvolver uma nova metodologia de avaliaÃÃo e implementaÃÃo de melhorias na interface de um ventilador pulmonar mecÃnico de uma unidade de terapia intensiva (UTI) segundo princÃpios heurÃsticos. MÃtodos: Estudo experimental, utilizando-se duas metodologias: uma centrada na avaliaÃÃo heurÃstica por expert, e a segunda, centrada em uma avaliaÃÃo comparativa por nÃo experts. Realizou-se durante o perÃodo de janeiro de 2013 a marÃo de 2014, no LaboratÃrio da RespiraÃÃo (RespLab). A pesquisa dividiu-se em 3 fases: 1Â) avaliaÃÃo da usabilidade de seis habilidades (ligar; ajustar ou alterar modos ventilatÃrios e seus parÃmetros; ajustar e reagir apropriadamente os diferentes tipos de alarmes ; monitorar parÃmetros de mecÃnica respiratÃria, acionar e ajustar o modo de ventilaÃÃo nÃo invasiva) da interface por usuÃrios experts; 2Â) ImplementaÃÃo das sugestÃes de melhorias na interface por uma equipe de engenheiros especialistas em ventilaÃÃo mecÃnica; 3Â) ComparaÃÃo entre interfaces (antiga e nova), por usuÃrios nÃo experts, avaliando 6 tarefas (ligar, ajuste do paciente, ajuste do modo de ventilaÃÃo a volume controlado (VCV), mensuraÃÃo da mecÃnica, ajuste do modo de ventilaÃÃo a pressÃo controlada (PCV), ajuste do modo de ventilaÃÃo a pressÃo de suporte (PSV). A anÃlise da 1Â fase foi descritiva. Os desfechos da 3Â fase foram: tempo de execuÃÃo e acertos das tarefas, e escore de usabilidade atravÃs da Escala Visual AnalÃgica (E.V.A.). Resultados: 1Â fase: Participaram 8 profissionais experts. Ao total, foram listados 93 problemas. Os princÃpios mais infringidos foram: 5 (PrevenÃÃo de erro), 1 (Visibilidade do Status do Sistema) e 7 (Flexibilidade e eficiÃncia de utilizaÃÃo). 2Â fase: repassados e discutidos todos os relatÃrios preenchidos pelos usuÃrios experts. ModificaÃÃes na interface foram realizadas seguindo as sugestÃes e princÃpios heurÃsticos. 3Â fase: ajuste do VCV, mecÃnica ventilatÃria e ajuste do PSV necessitaram de maior tempo para execuÃÃo; p=0,02 para o tempo de execuÃÃo da tarefa de ligar, quando usado pela primeira vez, para a interface antiga; p=0,02 para o ajuste correto do PSV quando realizado pela primeira vez na interface nova; p=0,08 para o escore de usabilidade, favorecendo a interface nova. ConclusÃo: Foi possÃvel desenvolver uma nova metodologia de avaliaÃÃo e implementaÃÃo de melhorias na interface de um ventilador pulmonar mecÃnico de UTI segundo os princÃpios heurÃsticos.

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Almgren, Birgitta. "Endotracheal Suction a Reopened Problem". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4798.

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Lemoignan, Josée. "Decision-making for assisted ventilation in amyotrophic lateral sclerosis". Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101862.

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Amyotrophic lateral sclerosis (ALS) is a progressive neurological disease that leads to respiratory compromise and eventually death within two to five years. Even though people with ALS must make many treatment decisions, none has such a significant impact on quality of life and survival as the one pertaining to assisted ventilation. A qualitative research study was undertaken to elicit factors that are pertinent to this decision-making process. Ten individual, semi-structured interviews were conducted with individuals with ALS. Six main themes emerged from the interviews. These are: meaning of the intervention, the importance of context, values, and fears in decision-making, the need for information, and adaptation/acceptance of the intervention. Based on these findings, it is argued that a pluralistic conception of autonomy as well as a shared decision-making model is better suited to give high priority to patient autonomy in this context. Some recommendations to improve clinical practice are proposed.

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Johnson, Patricia Lee, i n/a. "Being At Its Most Elusive: The Experience of Long-Term Mechanical Ventilation in a Critical Care Unit". Griffith University. School of Nursing, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20030926.154232.

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This research study explored the meanings former patients attributed to being on long-term mechanical ventilation in a critical care unit (CCU). An interpretive phenomenological-ontological perspective informed by the philosophical tenets of Heidegger (1927/1962) was used to examine the lived experience of a group of people who had previously been hospitalised in one of three critical care units in southeast Queensland, Australia, during which time they were on a mechanical ventilator for a period of seven days or more. Data were collected using 14 unstructured audio-taped interviews from participants, who had indicated that they were willing and able to recall aspects of their critical care experience. The data were analysed using the method developed by van Manen (1990). A total of nine people participated in the study, of which six were male and three female. Their ages ranged from 21 to 69 years. Thematic analysis of the data revealed four themes: Being thrown into an uneveryday world; Existing in an uneveryday world; Reclaiming the everyday world; and Reframing the experience. Throughout the description of these themes, excerpts from the interviews with the participants are provided to demonstrate, and bring to light the meaning and interpretations constructed. From this thematic analysis, a phenomenological description drawing on Heidegger's tenets of Being was constructed. Titled Being at its most elusive, this description showed that participants experienced momentary lapses of: situation, engagement, concern and care, temporality, and the ability to self-interpret. These findings highlight and affirm the relevance of Heidegger's ontological tenets to reveal Being. The findings of this study served as a basis for a number of recommendations relating to nursing practice, education and research. Recommendations relating to practice include: constructing a more patient-friendly critical care environment, increased involvement of patients and their families in decision making and patient care activities; ensuring adequate critical care nursing staff levels; ensuring and maintaining appropriate skill level of critical care nurses; enhancing methods of communication with patients; planning for effective patient discharge and adoption of a designated nurse position for discharge planning; providing opportunities for follow up contact of patients once they are discharged from CCU; and promoting the establishment of follow up services for former CCU patients, and their families. Recommendations relating to critical care education include: incorporating more in-depth information of the psychological and social aspects of patient and family care into care planning; incorporating communication and counselling education and training to assist nurses caring for mechanically ventilated patients, and their families; further education regarding the role and responsibilities of patient discharge planning from CCU; incorporating more advanced research skills training and utilisation of research findings into practice; and the provision of appropriate and ongoing training and education in areas such as manual handling and communication skills for all health care staff involved in the direct care of CCU patients. This study also recommended that further research be undertaken to: examine and compare different sedative and analgesic protocols and their effects on the incidence of nightmares and hallucinations reported by CCU patients; replicate this study in a group of patients from different cultural or ethnic backgrounds; evaluate the efficacy of current methods for communicating with intubated and mechanically ventilated patients in the CCU; develop, test and evaluate the efficacy of new methods for communicating with intubated and mechanically ventilated patients in the CCU; examine CCU patients' perceived level of control and power; explore the extent and type of involvement patients would like to have in their care whilst in the CCU; investigate the extent and type of problems experienced by CCU patients after discharge; explore the usefulness and appropriateness of personal diaries for individual patients as an aid to assist in understanding and resolving their CCU experience; and examine the value of follow up contacts by CCU staff to former patients and their families. In summary, the findings from this study add substantial knowledge to critical care nurses' understanding and knowledge about what it means to be on long-term mechanical ventilation in a critical care unit. Findings will help inform future critical care nursing practice and education, and the provision of holistic and evidenced-based care.

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Johnson, Patricia Lee. "Being At Its Most Elusive: The Experience of Long-Term Mechanical Ventilation in a Critical Care Unit". Thesis, Griffith University, 2003. http://hdl.handle.net/10072/368088.

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This research study explored the meanings former patients attributed to being on long-term mechanical ventilation in a critical care unit (CCU). An interpretive phenomenological-ontological perspective informed by the philosophical tenets of Heidegger (1927/1962) was used to examine the lived experience of a group of people who had previously been hospitalised in one of three critical care units in southeast Queensland, Australia, during which time they were on a mechanical ventilator for a period of seven days or more. Data were collected using 14 unstructured audio-taped interviews from participants, who had indicated that they were willing and able to recall aspects of their critical care experience. The data were analysed using the method developed by van Manen (1990). A total of nine people participated in the study, of which six were male and three female. Their ages ranged from 21 to 69 years. Thematic analysis of the data revealed four themes: Being thrown into an uneveryday world; Existing in an uneveryday world; Reclaiming the everyday world; and Reframing the experience. Throughout the description of these themes, excerpts from the interviews with the participants are provided to demonstrate, and bring to light the meaning and interpretations constructed. From this thematic analysis, a phenomenological description drawing on Heidegger's tenets of Being was constructed. Titled Being at its most elusive, this description showed that participants experienced momentary lapses of: situation, engagement, concern and care, temporality, and the ability to self-interpret. These findings highlight and affirm the relevance of Heidegger's ontological tenets to reveal Being. The findings of this study served as a basis for a number of recommendations relating to nursing practice, education and research. Recommendations relating to practice include: constructing a more patient-friendly critical care environment, increased involvement of patients and their families in decision making and patient care activities; ensuring adequate critical care nursing staff levels; ensuring and maintaining appropriate skill level of critical care nurses; enhancing methods of communication with patients; planning for effective patient discharge and adoption of a designated nurse position for discharge planning; providing opportunities for follow up contact of patients once they are discharged from CCU; and promoting the establishment of follow up services for former CCU patients, and their families. Recommendations relating to critical care education include: incorporating more in-depth information of the psychological and social aspects of patient and family care into care planning; incorporating communication and counselling education and training to assist nurses caring for mechanically ventilated patients, and their families; further education regarding the role and responsibilities of patient discharge planning from CCU; incorporating more advanced research skills training and utilisation of research findings into practice; and the provision of appropriate and ongoing training and education in areas such as manual handling and communication skills for all health care staff involved in the direct care of CCU patients. This study also recommended that further research be undertaken to: examine and compare different sedative and analgesic protocols and their effects on the incidence of nightmares and hallucinations reported by CCU patients; replicate this study in a group of patients from different cultural or ethnic backgrounds; evaluate the efficacy of current methods for communicating with intubated and mechanically ventilated patients in the CCU; develop, test and evaluate the efficacy of new methods for communicating with intubated and mechanically ventilated patients in the CCU; examine CCU patients' perceived level of control and power; explore the extent and type of involvement patients would like to have in their care whilst in the CCU; investigate the extent and type of problems experienced by CCU patients after discharge; explore the usefulness and appropriateness of personal diaries for individual patients as an aid to assist in understanding and resolving their CCU experience; and examine the value of follow up contacts by CCU staff to former patients and their families. In summary, the findings from this study add substantial knowledge to critical care nurses' understanding and knowledge about what it means to be on long-term mechanical ventilation in a critical care unit. Findings will help inform future critical care nursing practice and education, and the provision of holistic and evidenced-based care.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Nursing
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Lindahl, Berit. "Möten mellan människor och teknologi : berättelser från intensivvårdssjuksköterskor och personer som ventilatorbehandlas i hemmet /". Umeå : Department of Nursing, Umeå University, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-495.

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Saraiva, Mateus Sasso. "Manobra de hiperinsuflação com ventilador mecânico : uma revisão sistematica com metanálise". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/159642.

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Fundamento: A ventilação mecânica (VM) é um dos suportes de vida utilizados durante a internação em unidade de terapia intensiva. Entretanto, a alteração no mecanismo fisiológico de depuração mucociliar é um dos efeitos deletérios causados pela VM e pela prótese endotraqueal. Dessa forma, a fisioterapia respiratória objetiva manter as vias aéreas pérvias e as unidades alveolares expandidas, facilitando a ventilação pulmonar e para isso podem ser utilizadas manobras como hiperinsuflação manual (HM) ou hiperinsuflação com ventilador mecânico (HVM). Objetivo: Revisar sistematicamente os efeitos da HVM comparado com a HM no volume de secreção depurado, pneumonia associada à VM e tempo de VM em pacientes adultos em VM invasiva; e secundariamente, determinar os efeitos HVM nas variáveis respiratórias e hemodinâmicas. Métodos: Foi realizada uma busca sistemática nas bases de dados Cochrane CENTRAL, MEDLINE, Lilacs, PEDro e Embase, além de busca manual em referências de estudos publicados até agosto de 2016. Foram incluídos ensaios clínicos randomizados (ECRs) com pacientes adultos em VM que foram submetidos à manobra HVM comparando com manobra HM. Dois revisores independentes realizaram a seleção dos estudos, a extração dos dados e a avaliação da qualidade metodológica. Resultados: Do total de 3.949 artigos, três ECRs foram incluídos, totalizando 96 indivíduos. Foi observado que ambas as intervenções melhoram as variáveis respiratórias: volume de secreção (0,08g; IC95%: -0,70 a 0,85), complacência estática (1,01ml/cmH2O; IC95%: -5,80 a 7,83), complacência dinâmica (1,47 cmH2O; IC95%: - 3,43 a 6,36), relação PaO2/FiO2 (11,18; IC 95%: -26,28 a 48,65) e pressão arterial de dióxido de carbono (-0,38 mmHg; IC 95%: -2,78 a 2,03), sem diferença entre HVM e HM. Nenhum dos estudos incluídos avaliou as variáveis pneumonia associada à VM e tempo de VM. Conclusões: Esta revisão sistemática com metanálise, demonstrou que ambas as intervenções, melhoram os desfechos volume de secreção, complacência estática, complacência dinâmica, relação PaO2/FiO2 e pressão arterial de dióxido de carbono e que não existe diferença entre as mesmas, entretanto, devido as limitações dos estudos incluídos, novos estudos são necessários para confirmação dos achados.
Background: Mechanical ventilation (MV) is one of the supports used during intensive care unit admission. However, the change in the physiological mechanism of mucociliary clearance is one of the deleterious effects caused by MV and endotracheal prosthesis. Thus, respiratory physiotherapy aims to maintain the patent airways and expanded alveolar units, facilitating pulmonary ventilation and for this can be used maneuvers such as manual hyperinflation (HM) or hyperinflation with mechanical ventilator (HVM). Objective: To systematically review the effects of HVM compared with HM on the volume of depurated secretion, MV-associated pneumonia and MV time in adult patients in invasive MV; and secondarily to determine HVM effects on respiratory and hemodynamic variables. Methods: A systematic search was performed in the Cochrane CENTRAL, MEDLINE, Lilacs, PEDro and Embase databases, as well as a manual search in references of studies published up to August 2016. Randomized clinical trials (RCTs) were included, with adult patients in MV, that were submitted to the HVM maneuver comparing with HM maneuver. Two independent reviewers selected the studies, extracted data and assessed the methodological quality. Results: Of the total of 3,949 articles, three RCTs were included, totaling 96 individuals. It was observed that both interventions improved the respiratory variables: volume of secretion (0.08g, 95% CI: -0.70 to 0.85), static compliance (1.01ml / cmH2O, 95% CI: -5.80 to 7 , 83%), dynamic compliance (1.47 cmH2O, 95% CI: -3.43 to 6.36), PaO2 / FiO2 ratio (11.18; 95% CI: -26.28 to 48.65), and blood pressure Of carbon dioxide (-0.38 mmHg, 95% CI: -2.78 to 2.03), with no difference between HVM and HM. None of the included studies evaluated the variables pneumonia associated with MV and time of MV. Conclusions: This systematic review with meta-analysis has shown that both interventions improve the secretion volume, static compliance, dynamic compliance, PaO2 / FiO2 ratio and blood pressure of carbon dioxide and that there is no difference between them, however, due to limitations of the included studies, further studies are needed to confirm the findings.

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Nemer, Sérgio Nogueira. "Avaliação da força muscular inspiratória (Pi Max), da atividade do centro respiratório (P 0.1) e da relação da atividade do centro respiratório/força muscular inspiratória (P 0.1 / Pi Max) sobre o desmame da ventilação mecânica". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/5/5150/tde-02082007-104326/.

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Introdução: a hipótese deste estudo é de que a Pressão inspiratória máxima, Pressão de oclusão traqueal e sua razão podem predizer a evolução do desmame da ventilação mecânica em uma população mista de Terapia Intensiva. Métodos: A Pi Max , P 0.1 e a razão P 0.1 / Pi Max foram mensuradas em setenta pacientes consecutivos , intubados ou traqueostomizados, e ventilados mecanicamente, que preencheram os critérios para desmame da ventilação mecânica. Após a mensuração da Pi Max, P 0.1 e ainda da freqüência respiratória e volume corrente em litros com o cálculo da relação FR/VC e do produto P 0.1 x FR/VC, os pacientes foram submetidos a um teste de respiração espontânea. Os pacientes que toleraram o teste de respiração espontânea e não precisaram retornar para a ventilação mecânica no período de 24 horas foram considerados desmamados. A sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo, diagnóstico de acurácia e a área sob a curva ROC (receiver operating characteristic curve) foram calculadas. Resultados: Os valores médios da P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foram de 2,49±1,2, -34,6±13, 0,07±0,01, 75,4±33 e 184,6±123 respectivamente para os pacientes desmamados e 4,36± 2,0, -32,1±11,0 , 0,15± 0,09, 148,4± 42 e 652,9± 358 para os não desmamados da ventilação mecânica. Todos os índices distinguiram entre os pacientes desmamados e não desmamados, à exceção da Pi Max. A sensibilidade para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foi de 78,85, 65,38, 80,77, 82,69, 88,46 respectivamente. A especificidade para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foi de 72,2, 38,8, 72,2, 83,3, 72,2 respectivamente. Os valores preditivos positivos para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foram respectivamente 89,1, 75,5, 89,3, 93,4 e 90,2. Os valores preditivos negativos para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foram respectivamente de 54,1, 28,0, 56,5, 62,5 e 68,4. O diagnóstico de acurácia para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foi respectivamente de 77,1, 58,5, 78,5, 82,8 e 84,2. As áreas abaixo da curva ROC para a P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC foram respectivamente 0,76± 0,06, 0,52±0,08 , 0,78±0,06, 0,90±0,04 e 0,84±0,05. A comparação da áreas abaixo da curva ROC mostrou que os melhores índices foram a relação FR/VC, o produto P 0.1 x FR/VC e a relação P 0.1 / Pi Max não havendo diferença estatística entre eles. A pior área abaixo da curva ROC foi do índice Pi Max. Os índices de desmame da ventilação mecânica P 0.1, Pi Max e P 0.1/ Pi Max não foram diferentes estatisticamente entre os pacientes intubados e traqueostomizados. Conclusão: os melhores índices foram a relação FR/VC, o produto P 0.1 x FR/VC e a relação P 0.1 / Pi Max não havendo diferença estatística entre eles.
Introduction: We hypothesized that maximal inspiratory pressure (Pi Max), airway tracheal occlusion pressure (P 0.1) and its ratio (P 0.1/Pi Max) can be used to predict weaning outcome in a mixed ICU mechanically ventilated patients. Methods: Pi Max, P 0.1 and P 0.1 / Pi Max ratio were measured in seventy consecutive intubated or tracheostomized, mechanically ventilated patients, who fulfilled weaning criteria. After these measurements of Pi Max, P0.1, respiratory rate and expiratory tidal volume (L) with the calculation of f / Vt ratio and the product P0.1x f / Vt , the patients were submitted to a spontaneous breathing trial (SBT) . Those who were able to sustain the SBT and had no need to return to mechanical ventilation in the following 24 hours were considered weaned. The sensitivity, specificity, positive predictive value, negative predictive value, diagnostic accuracy and Receiver- operating-characteristics (ROC) curves for this population were calculated. Results: The mean value of P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC e P 0.1 x FR /VC were 2,49 ±1,2, -34,6± 13, 0,07± 0,01, 75,4±33 and 184,6±123 respectively for the weaned patients and 4,36± 2,0, -32,1±11,0 , 0,15± 0,09, 148,4± 42 e 652,9± 358 for the not weaned patients. All the indexes distinguished between the weaned and not weaned patient, except for the Pi Max. The sensitivity for the P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 78,85, 65,38, 80,77, 82,69, 88,46. The specificity for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were 72,2, 38,8, 72,2, 83,3, 72,2 respectively. The positive predictive value for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 89,1, 75,5, 89,3, 93,4 e 90,2. The negative predictive value for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 54,1, 28,0, 56,5, 62,5 e 68,4. The diagnostic accuracy for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 77,1, 58,5, 78,5, 82,8 e 84,2. The area under the ROC curves for P 0.1 , Pi Max, P 0.1 / Pi Max, FR / VC and P 0.1 x FR /VC were respectively 0,76± 0,06, 0,52±0,08 , 0,78±0,06, 0,90±0,04 e 0,84±0,05. The comparison among the areas under the ROC curves showed that the best weaning indexes were f / Vt ratio, the product P 0.1 x f / Vt and the P0.1/ Pi Max ratio with no statistic differences among them. The Pi Max presented the smaller area under the ROC curve. The weaning indexes P 0.1, Pi Max e P 0.1/ Pi Max were not statistically different between intubated or tracheostomized patients. Conclusion: The best weaning indexes were f/Vt ratio , the product P 0.1 x f/Vt and the P 0.1 / Pi Max ratio with no statistically difference among them.

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Nakamura, Maria Aparecida Miyuki. "Desempenho dos ventiladores convencionais em ventilação não invasiva: impacto da máscara total face® em modelo mecânico". Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/5/5160/tde-29012009-111311/.

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INTRODUÇÃO: O sucesso da terapia com ventilação não invasiva com pressão positiva (VNIPP) está associada com a escolha adequada da interface. A máscara Total face® (TF) é considerada mais confortável, porém possui grande espaço morto (875 ml) e vazamento constante elevado. Os ventiladores próprios para ventilação mecânica invasiva (convencionais) têm sido utilizados, habitualmente, para ventilação não invasiva em ambiente de UTI. OBJETIVOS: Avaliar o desempenho de nove ventiladores convencionais com uso da máscara TF e compará-los com um ventilador próprio para VNIPP (Respironics BiPAP Vision). MÉTODOS: Utilizou-se um modelo com dois simuladores mecânicos do sistema respiratório conectados a uma cabeça de manequim onde foi adaptada a máscara TF que foi conectada aos ventiladores testados. O esforço inspiratório foi simulado utilizando-se o modo pressão controlada. Os ventiladores foram testados na modalidade espontânea ventilação com pressão suporte sendo ajustados dois valores de PEEP (5 e 10cmH2O) e 3 valores de pressão suporte (5, 10 e 15 cmH2O). Foi testado se os ventiladores funcionavam com a máscara TF e seu desempenho em relação à compensação de vazamento, pressurização, pico de fluxo atingido, atrasos inspiratório e expiratório. RESULTADOS: O ventilador Vision funcionou em todas as situações. Quatro ventiladores convencionais funcionaram (Horus, Vela, E500 e Servo i). O principal problema com os ventiladores que não funcionaram foi o autodisparo e o desligamento do fluxo inspiratório. O pico de vazamento medido foi maior que 1L/s, em média, e o pico de fluxo gerado, muitas vezes, atingia a capacidade máxima em alguns ventiladores. A capacidade de compensar vazamento foi variável entre os ventiladores, mas aqueles com maior dificuldade (E500 e Horus) foram os que mantiveram os menores valores de PEEP e, também, maiores atrasos no disparo, os demais ventiladores, apresentaram atrasos iniciais menores que 100ms. A ciclagem ocorreu por critérios de segurança nos ventiladores Horus, Vela e E500 em algumas medidas. A capacidade de pressurização foi avaliada pelo cálculo do PTP com 500ms e com 1 segundo. A área de pressurização com 1 segundo ficou abaixo de 50% da área esperada para todos os ventiladores, inclusive para o Vision, específico para VNIPP, sendo que o pior desempenho foi do ventilador Horus. CONCLUSÕES: Entre nove ventiladores convencionais testados, apenas quatro funcionaram com a TF. O desempenho entre os ventiladores foi variável, sendo que, alguns deles não se mostraram adequado para uso com VNIPP usando a máscara TF. A maior dificuldade para o funcionamento dos ventiladores convencionais foi lidar com o grande vazamento, com ocorrência de autodisparos ou desligamento do fluxo de ar do ventilador, acusando desconexão. O vazamento de ar pelos orifícios da máscara é elevado. Os ventiladores Horus e E500 tiveram atrasos maiores que 100ms no disparo; e a ciclagem ocorreu por critérios de segurança em todos ventiladores convencionais, em algumas medidas, exceto o Servo i
BACKGROUND: The success of therapy with noninvasive ventilation with positive pressure (VNIPP) is associated with interface choice. The Total face® mask (TFM) is an interface considered more comfortable than other, but it has a large dead space (875 ml) and constant high leakage. However, intensive care ventilators have been usually used for noninvasive ventilation in the ICU environment, their ability to operate with high air leakage is not known. OBJECTIVES: To evaluate the performance of nine ICU ventilators using TFM and compare them with a VNIPP mode only ventilator (Respironics BiPAP Vision). METHODS: a mechanical respiratory system simulator with two compartments was adapted to TFM what was connected to tested ventilators. The inspiratory effort was simulated using pressure control mode in Newport E500 ventilator. The ventilators were tested in spontaneous mode being adjusted at two values of PEEP (5 and 10cmH2O) and 3 values of pressure support (5, 10 and 15 cmH2O). It was tested if ventilators worked properly with TFM and its performance to compensation for leakage, its pressurization, the capability to reach peak flow target, and trigger and cycling delays. RESULTS: The Vision ventilator worked properly in all situations. Four conventional ventilators (Horus, Vela, E500 and Servo) worked. The main problem with failed ventilator was auto triggering and inspiratory flow turning off. Among worked ventilators, peak inspiratory leakage average was greater than 1L / s , generated peak flow reached maximum capacity in some settings with NIV mode only ventilator. The ability to compensate for leak was variable between ventilators, but those with greater difficulty (E500 and Horus) maintained the lowest values of PEEP and also had great trigger delays, the other ventilators showed trigger delays smaller than 100ms. The cycling occurred by security criteria on Horus, Vela and E500 ventilators in some settings. The ability of pressurization was evaluated by calculating the PTP with 500ms and 1 second. The area of pressurization with 1 second remained below 50% of target area for all ventilators, including for Vision, specifically for VNIPP. Horus ventilator has the worst pressurization performance. CONCLUSIONS: Among nine conventional tested ventilators, only four worked with the TFM. The performance among the ventilators was variable; as a result some of them were not suitable for use with NIV using TFM. The greatest difficulty for conventional ventilator operation was dealing with the large leakage, occurring auto triggering or inspiratory flow turning off, alarming disconnection. The air leakage through the mask holes (exhalation port) was high. Horus and E500 ventilators had trigger delays greater than 100ms and cycling occurred by security criteria for all conventional ventilators, except the Servo, in some setting

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Couto, Lara Poletto. "Estudo do funcionamento da ventilação assistida proporcional plus em um sistema pulmonar mecânico". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/5/5150/tde-25102012-164038/.

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INTRODUÇÃO: Ventilação assistida proporcional plus é um novo conceito de suporte ventilatório assistido que visa atuar de acordo com os níveis de esforço inspiratório, mecânica respiratória e níveis de porcentagem de apoio. A complexa interação entre esses fatores que comandam a sua função é de difícil interpretação na prática clínica. O objetivo deste estudo é provocar alterações na complacência, resistência e esforços inspiratórios, em um sistema pulmonar mecânico, para entender o funcionamento e as respostas desse modo nas suas diferentes porcentagens de apoio. MÉTODOS: No Laboratório de Ventilação Mecânica da Disciplina de Pneumologia da Faculdade de Medicina da Universidade de São Paulo, um ventilador Interplus da marca Intermed foi conectado em um pulmão mecânico da marca Michigan Instruments Inc, com a finalidade de gerar diferentes níveis de esforços inspiratórios e para disparar o ventilador Puritan-Bennett 840 da marca Covidien. Os volumes correntes expirados foram medidos e posteriormente comparados através do método estatístico ANOVA two-way, para 10 níveis de porcentagem de apoio (de 5% a 95%), 3 níveis de complacência (50, 100 e 150 mL/cmH2O), 3 níveis de resistência (5, 20 e 50 cmH2O/L/s) e 4 níveis de esforço inspiratório (-2, -5, -8 e -15 cmH2O). RESULTADOS: Trezentas e sessenta medidas de volume corrente expirado foram obtidas. Os volumes correntes expirados aumentaram significativamente com o incremento dos esforços inspiratórios, durante altos esforços inspiratórios e altas complacências. Diminuíram significativamente durante o incremento das resistências, especialmente quando combinado com baixos esforços inspiratórios e baixas complacências. O fenômeno de sobreassistência (runaway) ocorreu com porcentagem de apoio de 95% combinada com alta resistência e alta complacência. CONCLUSÃO: O modo ventilação assistida proporcional plus respondeu adequadamente às alterações provocadas nas complacências e nos esforços inspiratórios testados. Respondeu à situações de resistência extremamente alta somente quando associado com altos esforços inspiratórios. Não houve fenômeno de sobreassistência em porcentagens de apoio menores que 95%.
BACKGROUND: Proportional assist ventilation plus (PAV+) is a new concept of assist ventilatory support conceived to act according to the levels of inspiratory efforts, respiratory mechanics and percentages levels of assistance. This complex interaction among the factors commanding its function is difficult to detect in clinical setting. This study aimed to provoke changes in compliance, resistance and inspiratory efforts in a lung simulator to understand the responses of PAV+ support. METHODS: In the Mechanical Ventilation Laboratory at University of São Paulo, an Inter Plus ventilator (Intermed ®) connected to lung simulator (Michigan Instruments Inc) acted triggering Puritan-Bennett 840 ventilator (Covidien ®) at different levels of inspiratory efforts. Expiratory tidal volumes were measured and compared (ANOVA-2-way) at 10 levels of PAV+ support (from 5% to 95%), 3 levels of lung simulator compliance (50, 100, 150 mL/cmH20), 3 levels of airway resistance (5, 20, 50 cmH20/L/s) and 4 levels of inspiratory effort ( -2, -5, -8, -15 cmH20). RESULTS: A total of 360 tidal volumes were measured. They increased significantly during increment of inspiratory efforts and during higher inspiratory efforts with higher compliances. They decreased significantly during respiratory resistance increments, especially when combined with low inspiratory efforts and compliances. Runaway occurred during PAV+ support of 95% combined with high respiratory resistance and compliance. CONCLUSIONS: PAV+ responded adequately to provoked changes in the tested respiratory compliances and inspiratory efforts. It responded to very high resistance only when associated with high inspiratory efforts. There was no runaway phenomenon during PAV+ assistance below 95%.

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Elshafie, Ghazi Abdelgadir E. "Ventilatory mechanics in thoracic surgery". Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7141/.

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This thesis proved that chest wall motion analysis technology could be used in thoracic surgery to answer a number of clinical and physiological questions. We used it either as a diagnostic tool or for the evaluation of an intervention outcome. We divided its use as a diagnostic tool into two categories; 1- diagnosis before surgery and 2- diagnosis after surgery. In the evaluation of an intervention outcome, we divided its use after a number of interventions: 1. Cosmetic Surgery: Chapter 5: The Effect of Pectus Carinatum (Pigeon Chest) Repair on Chest Wall Mechanics 2. Prognostic Surgery: a) Chapter 4: The Effect of Chest Wall Reconstruction on Chest Wall Mechanics b) Chapter 10: Late Changes in Chest Wall Mechanics Post Lung Resection: The Effect of Lung Cancer Resection In COPD patients 3. Palliative Surgery: a) Chapter 6: The Effect of Lung Volume Reduction Surgery on Chest Wall Mechanics b) Chapter 3: The Effect of Diaphragmatic Plication (Fixation) on Chest Wall Mechanics 4. Post-operative Intervention: Chapter 8: The Effect of Thoracic Nerve Blocks on Chest Wall Mechanics.

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Young, Peter Jeffrey. "Pulmonary aspiration in mechanical ventilation". Thesis, University of East Anglia, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323263.

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Pulmonary aspiration in mechanical ventilation occurs despite appropriate inflation of the tracheal tube cuff. After anaesthesiath is can causep ostoperative and, in critically ill patients, ventilator-associated pneumonia. Cuff over-inflation exerts excessive pressure on the tracheal mucosa causing injury. High volume low pressure (HVLP) cuffs permit wall pressure control as the intracuff pressure (CP) is the tracheal wall pressure (TWP). Unfortunately, at the cuff wall, folds and channels and, therefore, fluid leakage occur. Low volume high pressure (LVHP) cuffs develop neither folds nor associated leakage, but TWP is not easily inferred from CP and excessive pressures can result in tracheal injury. This thesis examines the problem of aspiration in a model, in anaesthetised patients and in the critically ill. In the model, protection against leakage resulted from positive end-expiratory pressure and cuff lubrication. Two tracheal cuff prototypes are introduced. Firstly, the compliant HVLP cuff is one with a tapered shape made of highly compliant material. Within the model this produced a circumferential band at the cuff wall without folds thus effectively eliminating channels and leakage. Secondly, the prototype pressure limited cuff (PLC) is a latex LVHP cuff with inflation characteristics such that TWP can be inferred from CP and maintained at an acceptable level. Within the model the PLC prevented leakage at acceptable TWPs. For clinical use a constant pressure inflation device is required to provide uninterrupted protection, although notably HVLP cuffs allow leakage despite this. The PLC prevented dye aspiration in 100% of tracheally intubated critically ill patients compared with 13% of the control HVLP group (p<0.01). A silicone cuff with similar inflation characteristics, yet improved biocompatability and shelf life, prevented dye aspiration in 100% of patients with tracheostomies compared to 0% of the HVLP control group (p=0.001). HVLP cuff lubrication delayed dye aspiration for 1 to 5 days (p<0.05).

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Powelson, Stephen K. (Stephen Kirby). "Design and prototyping of a low-cost portable mechanical ventilator". Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59954.

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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. [10]).
This paper describes the design and prototyping of a low-cost portable mechanical ventilator for use in mass casualty cases and resource-poor environments. The ventilator delivers breaths by compressing a conventional bag-valve mask (BVM) with a pivoting cam arm, eliminating the need for a human operator for the BVM. An initial prototype was built out of acrylic, measuring 11.25 x 6.7 x 8 inches (285 x 170 x 200 mm) and weighing 9 lbs (4.1 kg). It is driven by a stepper motor powered by a 14.8 VDC battery and features an adjustable tidal volume of up to 900 mL, adjustable breaths per minute (bpm) of 5-30, and inhalation to exhalation time ratio (i:e ratio) options of 1:2, 1:3 and 1:4. Tidal volume, breaths per minute and i:e ratio are set via user-friendly knobs, and the settings are displayed on an LCD screen. The prototype also features an assist-control mode and an alarm to indicate over-pressurization of the system. Future iterations of the device will be fully calibrated to medical standards and include all desired ventilator features. Future iterations will be further optimised for low power-consumption and will be designed for manufacture and assembly. With a prototyping cost of only $420, the bulk-manufacturing price for the ventilator is estimated to be less than $100. Through this prototype, the strategy of cam-actuated BVM compression is proven to be a viable option to achieve low-cost, low-power portable ventilator technology that provides essential ventilator features at a fraction of the cost of existing technology. Keywords: Ventilator, Bag Valve Mask (BVM), Low-Cost, Low-Power, Portable and Automatic.
by Stephen K. Powelson.
S.B.

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Sperber, Jesper. "Protective Mechanical Ventilation in Inflammatory and Ventilator-Associated Pneumonia Models". Doctoral thesis, Uppsala universitet, Infektionssjukdomar, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-282602.

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Severe infections, trauma or major surgery can each cause a state of systemic inflammation. These causes for systemic inflammation often coexist and complicate each other. Mechanical ventilation is commonly used during major surgical procedures and when respiratory functions are failing in the intensive care setting. Although necessary, the use of mechanical ventilation can cause injury to the lungs and other organs especially under states of systemic inflammation. Moreover, a course of mechanical ventilator therapy can be complicated by ventilator-associated pneumonia, a factor greatly influencing mortality. The efforts to avoid additional ventilator-induced injury to patients are embodied in the expression ‘protective ventilation’. With the use of pig models we have examined the impact of protective ventilation on systemic inflammation, on organ-specific inflammation and on bacterial growth during pneumonia. Additionally, with a 30-hour ventilator-associated pneumonia model we examined the influence of mechanical ventilation and systemic inflammation on bacterial growth. Systemic inflammation was initiated with surgery and enhanced with endotoxin. The bacterium used was Pseudomonas aeruginosa. We found that protective ventilation during systemic inflammation attenuated the systemic inflammatory cytokine responses and reduced secondary organ damage. Moreover, the attenuated inflammatory responses were seen on the organ specific level, most clearly as reduced counts of inflammatory cytokines from the liver. Protective ventilation entailed lower bacterial counts in lung tissue after 6 hours of pneumonia. Mechanical ventilation for 24 h, before a bacterial challenge into the lungs, increased bacterial counts in lung tissue after 6 h. The addition of systemic inflammation by endotoxin during 24 h increased the bacterial counts even more. For comparison, these experiments used control groups with clinically common ventilator settings. Summarily, these results support the use of protective ventilation as a means to reduce systemic inflammation and organ injury, and to optimize bacterial clearance in states of systemic inflammation and pneumonia.

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Grano, Joan. "Ventilator-Associated Complications in the Mechanically Ventilated Veteran". Doctoral diss., University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5749.

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Surveillance of ventilator-associated pneumonia (VAP) has been the common outcome measurement used for internal and external benchmarking for mechanically ventilated patients; and although not a clinical definition, it is commonly used as an outcome measurement for research studies. Criteria in the VAP definition include both subjective and objective components, leading to questions of validity. In addition, recent legislation has mandated the public reporting of healthcare-associated infections, including VAP, in many states. Infectious disease experts have recently recommended monitoring a new outcome, ventilator-associated events (VAE), that contain specific objective criteria. The Centers for Disease Prevention and Control (CDC) have refined this definition and released a new VAE protocol and algorithm, replacing the VAP surveillance definition, as a result. The VAE protocol assesses for ventilator-associated conditions (VAC). The primary aims of this study were to determine the incidence of VAC; and to assess four predictors for VAC, including two VAP prevention strategies (use of the subglottic secretion drainage endotracheal-tube [SSD-ETT]), and daily sedation vacation); and two patient-related factors (alcohol withdrawal during mechanical ventilation, and history of COPD). In addition, the incidence for VAE, using a new national algorithm was determined. Using a retrospective study design, electronic medical records of 280 veterans were reviewed to identify cases of VAC using the VAE algorithm. The setting was two intensive care units (ICU) at a large Veterans Administration Healthcare System (VAHCS) from October 2009 to September 2011. In addition to demographic information, variables were collected to determine if cases met event criteria (VAC, infection-related ventilator-associated complication [IVAC], and possible or probable VAP). Incidence rates were calculated for VAC and IVAC. Comparative data between those with and without VAC were assessed with independent sample T-test or non-parametric equivalents. The study sample was predominantly male (97.1%), Caucasian (92.1%), non-Hispanic (90.7%); with a mean (SD) age of 67.2 (10.4) years. Twenty patients met the VAC definition resulting in a VAC incidence of 7.38 per 1000 ventilator days. There were no statistically significant differences in demographics or disease characteristics found between the two groups (patients with VAC and patients without VAC). Using logistic regression, the impact of the four predictors for VAC was assessed. None of the four explanatory variables were predictive of the occurrence of VAC. Secondary outcomes (e.g. mechanical ventilation days, ICU days, hospital days, and mortality) of veterans with VAC were compared to veterans without VAC. Results indicated that the VAC group was associated with a significantly longer duration of ICU stay, longer mechanical ventilation period, more likely to have a tracheostomy, and had a higher mortality during hospitalization. Expanding mechanical ventilation quality performance measures to include VAE/VAC provides a better representation of infectious and non-infectious ventilator-associated problems, and provides more accurate morbidity and mortality in this high-risk ICU population. Further research is necessary to explore patient characteristics and prevention strategies that impact the development of all VAC.
Ph.D.
Doctorate
Nursing
Nursing
Nursing

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18

Lyazidi, Aissam. "Évaluation des performances et des limitations des ventilateurs sur banc d'essai". Thesis, Paris Est, 2010. http://www.theses.fr/2010PEST1073.

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Les ventilateurs ont connu des progrès technologiques considérables grâce à l'application de concepts physiologiques, à l'électronique, à l'informatique et la miniaturisation. Leurs conceptions et performances intrinsèques, en revanche, ont pu rester inégales sur certains points. L'objectif de ce travail a été d'évaluer sur un banc d'essai, avec un protocole, adapté aux problématiques soulevées en pratique clinique, tous les ventilateurs de réanimation, transport et de ventilation non invasive de façon rigoureuse et reproductible. Les résultats montrent que 1) l'erreur sur le volume réellement délivré est très fréquente et correspond facilement à 1ml/kg de volume supplémentaire ; le VT indiqué sur les ventilateurs est inférieur au VT réellement délivré ; 2) les performances des nouveaux ventilateurs ne présentent pas d'améliorations significatives par rapport aux meilleurs ventilateurs testés en 2000; les ventilateurs à turbine sont identiques ou proches des meilleurs ventilateurs conventionnels ; 3) les ventilateurs dédiés à la ventilation non invasive montrent de meilleures performances pour s'adapter à la présence de fuites ; 4) la ventilation par percussion intra-pulmonaire superposée à la ventilation conventionnelle peut réduire l'apport de l'humidification, influencer les volumes administrés et induire une pression expiratoire positive intrinsèque. Les tests sur banc montrent une grande hétérogénéité des performances. Une veille technologique semble indispensable pour évaluer tout nouveau ventilateur
The ventilators have markedly improved thanks to progress in respiratory physiology, in informatics and miniaturization. However, their intrinsic performances remain unequal. The aim was to evaluate ventilators performances on reproducible bench test studies adapted to clinical questions. Tests show that 1) the error of really delivered volume is approximately 1 ml/kg of additional volume; the tidal volume (VT) indicated on the ventilators was lower than the real delivered VT ; 2) Performances of new ventilators are comparable to the best ventilators tested in 2000 ; turbine ventilators are quite similar to best conventional ventilators ; 3) The ventilators dedicated to non invasive ventilation showed better performances to cope with leaks 4) The intrapulmonary percussive ventilation superimposed on conventional ventilation can reduce humidity, increase volumes and can generate intrinsic positive expiratory pressure. The bench tests showed a large heterogeneity of performances. A technological watch seems essential to evaluate all new ventilators

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Balaji, Ravishankar. "Breathing Entrainment and Mechanical Ventilation in Rats". Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1307743446.

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20

Mortimer, A. J. "High frequency jet ventilation : Mechanics and gas exchange". Thesis, University of Newcastle Upon Tyne, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373490.

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21

Clochesy, John Michael. "Factors influencing weaning adults from long-term positive pressure mechanical ventilatory support". Case Western Reserve University School of Graduate Studies / OhioLINK, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=case1057080137.

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Coisel, Yannaël. "Ventilation mécanique en anesthésie réanimation : évaluation des nouveaux modes ventilatoires en médecine péri-opératoire". Thesis, Montpellier 1, 2014. http://www.theses.fr/2014MON1T011/document.

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Chez un patient, les muscles respiratoires sont mis au repos lors de la défaillance de la fonction respiratoire, que cette défaillance soit involontaire (maladie, accident…) ou volontaire (anesthésie générale). Le patient est alors relié à un ventilateur artificiel, machine qui se charge de le faire respirer. Il existe de très nombreux types de ventilateurs artificiels, de qualité inégale, et chaque dispositif propose de multiples réglages pour ventiler le patient : les modes ventilatoires. Ces machines et leurs modes ventilatoires sont commercialisés et utilisés quotidiennement, mais très peu ont été évalués en situation clinique et leurs performances restent à démontrer. L'interaction de ces modes ventilatoires avec les muscles respiratoires du patient est ainsi actuellement méconnue. Dans ce travail, premièrement nous avons fait un état des lieux des pratiques de la ventilation mécanique en médecine péri-opératoire (patients au bloc opératoire et réanimation) ; secondairement, nous avons évalué sur banc d'essai au laboratoire les performances techniques des ventilateurs d'anesthésie et de réanimation de dernière génération dans des conditions statiques (ventilation contrôlée dans différentes conditions de pathologies pulmonaires) et dans des conditions dynamiques (ventilation spontanée assistée dans différentes situations de sevrage ventilatoire) et établi des critères de choix d'un ventilateur ; dans une troisième partie nous avons analysé chez le patient de réanimation au cours du sevrage de la ventilation mécanique le fonctionnement et le comportement des modes ventilatoires les plus évolués (Neurally Adjusted Ventilatory Assist (NAVA), Proportionnal Adaptive Ventilation + (PAV+), Adaptative Support Ventilation (ASV), Intellivent, Noisy-PSV) en comparaison avec le mode de référence qu'est la Ventilation Spontanée en Aide Inspiratoire (Pressure Support Ventilation). Finalement, nous présentons les perspectives de recherche et bénéfices potentiels attendus issus de ces études à travers nos projets de travaux expérimentaux et cliniques
In case of respiratory failure, the patient's respiratory muscles are put at rest. The patient is then linked to an artificial ventilator, which makes him breath. There are a huge number of artificial ventilators, of varying quality, and each device offers many different settings : the ventilatory modes. These devices and their ventilatory modes are marketed and used daily, but few of them have ever been evaluated in a clinical situation and their performances still need to be proven. Interactions between these ventilatory modes and respiratory muscles are presently unknown. In this work, we first made an inventory of mechanical ventilation in peri-operative medicine (patients in operating rooms and in intensive care units). Then, we evaluated on a bench test the technical performances of the latest generation of anesthesia and intensive care ventilators, in static conditions (controlled ventilation in different pathologic pulmonary conditions) and in dynamic conditions (assisted spontaneous breathing in different weaning situations), and we established criteria to check before choosing a ventilator. Third, we analysed the behaviour of several advanced ventilatory modes (Neurally Adjusted Ventilatory Assist (NAVA), Proportional Assist Ventilation Plus (PAV+), Adaptive Support Ventilation (ASV), Intellivent, Noisy-PSV) during ventilator weaning of intensive care patients compared to the reference weaning mode : Pressure Support Ventilation. Finally, we present research perspectives and potential benefits from our studies through our experimental and clinical project

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23

Kolandaivelu, Kumaran. "Development of a miniature high frequency ventilator for genetically engineered newborn mice". Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/60745.

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Kilander, Johanna, i Madeleine Frisell. "Variable expiration control for an intensive care ventilator". Thesis, Linköpings universitet, Institutionen för medicinsk teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-157761.

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Critical care patients are often connected to ventilators, to support or replace their breathing. The ventilators deliver a mixture of gas to the patient by applying a specific volume or pressure, and then the patient exhales passively. This thesis is based of the hypothesis that a slower reduction of the expiration pressure could benefit intensive care patients connected to a ventilator. To enable research within the area, a device which can control the expiration is needed. In this thesis project, an expiration valve was controlled to create different pressure patterns during expiration. To facilitate the research and the usage of the expiration control, an application software was created with the purpose to simulate relevant pressure, flow and volume curves. The prototype is an expiration cassette created for the ventilator Servo-i by Maquet Getinge Group. To enable flexibility, the prototype is external and no information is transmitted from or to the ventilator. The prototype has its own flow and pressure sensors. The different pressure patterns which the prototype uses are designed as a linear decrease and as if a constant resistance was added to the system. The user can also create their own pressure pattern, by deciding 20 pressure points in the duration of two seconds. The simulation application was designed with the ability to simulate the same pressure patterns available with the prototype. By using a lung model, it is possible to simulate the ideal pressure, flow and volume in the lungs which can be expected from the chosen expiration control. During the implementation, two different types of lung models were evaluated in order to determine the specificity required. The prototype was tested with settings which were chosen to challenge the performance of the control. Some problematic areas were detected, such as high pressures or large volumes. However, the prototype was judged to perform well enough to be used in animal trials. The lung model used for the simulation application was a simple model of the lung, consisting of a resistor and a capacitor in series. The simulations were compared with the real system with the purpose to get an indication on the difference between theory and reality. The application presents the expected behavior when using the expiration control. However, it should be kept in mind by the user that the application represents a theoretical model.

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25

Yuta, Toshinori. "Minimal Model of Lung Mechanics for Optimising Ventilator Therapy in Critical Care". Thesis, University of Canterbury. Mechanical Engineering, 2007. http://hdl.handle.net/10092/1608.

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Positive pressure mechanical ventilation (MV) has been utilised in the care of critically ill patients for over 50 years. MV essentially provides for oxygen delivery and carbon dioxide removal by the lungs in patient with respiratory failure or insufficiency from any cause. However, MV can be injurious to the lungs, particularly when high tidal pressures or volumes are used in the management of Acute Respiratory Distress Syndrome (ARDS) or similar acute lung injuries. The hallmark of ARDS is extensive alveolar collapse resulting in hypoxemia and carbon dioxide retention. Application of Positive End Expiratory Pressure (PEEP) is used to prevent derecruitment of alveolar units. Hence, there is a delicate trade-off between applied pressure and volume and benefit of lung recruitment. Current clinical practice lacks a practical method to easily determine the patient specific condition at the bedside without excessive extra tests and intervention. Hence, individual patient treatment is primarily a mixture of "one size- fits-all" protocols and/or the clinician's intuition and experience. A quasi-static, minimal model of lung mechanics is developed based on fundamental lung physiology and mechanics. The model consists of different components that represent a particular mechanism of the lung physiology, and the total lung mechanics are derived by combining them in a physiologically relevant and logical manner. Three system models are developed with varying levels of physiological detail and clinical practicality. The final system model is designed to be directly relevant in current ICU practice using readily available non-invasive data. The model is validated against a physiologically accurate mechanical simulator and clinical data, with both approaches producing clinically significant results. Initial validation using mechanical simulator data showed the model's versatility and ability to capture all physiologically relevant mechanics. Validation using clinical data showed its practicality as a clinical tool, its robustness to noise and/or unmodelled mechanics, and its ability to capture patient specific responses to change in therapy. The model's capability as a predictive clinical tool was assessed with an average prediction error of less than 9% and well within clinical significance. Furthermore, the system model identified parameters that directly indicate and track patient condition, as well as their responsiveness to the treatment, which is a unique and potentially valuable clinical result. Full clinical validation is required, however the model shows significant potential to be fully adopted as a part of standard ventilator treatment in critical care.

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Arief, Nyimas. "Automated Detection of Incomplete Exhalation as an Indirect Detection of Auto-PEEP on Mechanically Ventilated Adults". VCU Scholars Compass, 2013. http://scholarscompass.vcu.edu/etd/534.

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Auto-PEEP is auto positive end-expiratory pressure due to excessive amounts of alveolar gas produced by sustained recurrent incomplete exhalation. Incomplete exhalation occurs when the exhaled breath never reaches a flow rate of 0 L/min. The objective of this dissertation is to develop an automated detection system of auto-PEEP through incomplete exhalation as revealed by ventilator graphics for mechanically ventilated adults. Auto-PEEP can cause adverse effects if allowed to linger and if not quickly identified. An automated detection system will be instrumental in helping to quickly identify auto-PEEP. A computerized algorithm was developed to detect incomplete exhalation based on the following three parameters:1) Foi, was used to represent the value of the flow at the onset of inhalation, 2) ∆T, was used to represent the value of time difference between onset inhalation to the 0 L/min mark, and 3) slope threshold, a value set for the slope of change of flow over ∆T. Optimum parameters of the algorithm were achieved for Foi = -3 L/min, ∆T = 0.2 s, and slope threshold = 90 L-s/min. A novel data set was introduced to validate the algorithm, yielding no significant difference in true positive rates (t = 1.5, df = 12.402, p-value = 0.1408) and false positive rates (t = 1.9, df = 16.765, p-value = 0.0725) as outcomes for two-tailed t-tests comparing the novel and old data set. To determine the relationship between auto-PEEP and detection of sustained incomplete exhalation, a correlation of a linear model of the novel data set between auto-PEEP and the percentage of incomplete exhalation detection out of the existing breaths (index) was investigated. A linear model should interpret the index value that corresponds to significant auto-PEEP presence; unfortunately, no significant linear model was found between incomplete exhalation index and auto-PEEP (F1,62 = 1.67, p-value = 0.2010). However, there was a relationship between the intrinsic PEEP values and the incomplete exhalation index as functions of time. The automated detection algorithm produced by this work provides a non-invasive method of automatically detecting auto-PEEP.

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Júnior, Marcus Henrique Victor. "Implementation and assessment of a novel mechanical ventilatory system following a noisy ventilation regime". Instituto Tecnológico de Aeronáutica, 2014. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=3151.

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This study concerns the development of a novel mechanical ventilation system, with a view to analysing the results of a new mechanical ventilation technique, referred to noisy ventilation. Additionally, the study addresses the assessment of the system, involving the estimation of certain mechanical parameters of the respiratory system under noisy ventilation and discusses a pilot trial in vivo, with a pig. During acute respiratory failure, intubation and invasive mechanical ventilation may be life saving procedures. The general aim of mechanical ventilation is to provide adequate gas exchange support, while not damaging the respiratory system. This technique is one of the most important life support tools in the intensive care unit. However, it may also be harmful by causing ventilator induced lung injury and other undesirable effects. There is a growing interest in the development and use of variable mechanical ventilation performing variable volume and variable pressure controlled ventilation. The reasons are that this technique can improve lung functions and reduce lung damage, when compared to standard mechanical ventilation. Moreover, variable ventilation can improve lung mechanics and gas exchanges. The new ventilation system has to have the capabilities to perform a noisy ventilation regime, besides the standard mechanical ventilation. The development started with commercial devices: a mechanical ventilator and a personal computer, whose roles were to execute the noisy ventilation regime and to implement the new ventilation pattern by means of a ventilation routine, commanding the mechanical ventilator. After these two components were working together, a bench test was performed, in which a calibrated measuring device and a mechanical lung simulator were utilized. Considering that the system was working properly, it was possible to validate it by analysing the results. As the mechanical properties of the respiratory system are important quantities to know, a parameter estimation method was developed, with a view to estimating some relevant properties, such as compliance, positive end--expiratory pressure, resistance and others. The estimates were related to the adopted model for the respiratory system. In this study, four models were discussed: first order linear model, flow dependent resistance model, volume dependent elastance model and second order linear model. For each one, all parameters were estimated and the outcomes from each estimation were compared with the others, with a view to finding relationships between them and to evaluating the goodness of each model. Furthermore, as some parameters could be adjusted directly in the devices, adjusted and estimated values could also be compared. Finally, one trial in vivo was performed, with a view to assessing the behaviour of the system in a real situation and to showing the developed system to the research team. The system was set to work in a noisy and in a standard ventilation regime. It showed reasonable results in terms of quality of ventilation as well as reliability and maintainability of the ventilatory regime, during the whole test period. The developed parameter estimation methods were utilized to estimate the mechanical respiratory properties of the animal under test and to find cross relationships between these outcomes and others, such as those from blood gas, ultrasonography and electrical impedance tomography.

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Koombua, Kittisak. "Multiscale Modeling of Airway Inflammation Induced by Mechanical Ventilation". VCU Scholars Compass, 2009. http://scholarscompass.vcu.edu/etd/1841.

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Mechanical ventilation (MV) is a system that partially or fully assists patients whose respiratory system fails to achieve a gas exchange function. However, MV can cause a ventilator-associated lung injury (VALI) or even contribute to a multiple organ dysfunction syndrome (MODS) in acute respiratory distress syndrome (ARDS) patients. Despite advances in today technologies, mortality rates for ARDS patient are still high. A better understanding of the interactions between airflow from mechanical ventilator and the airway could provide useful information used to develop a better strategy to ventilate patients. The mechanisms, which mechanical ventilation induces airway inflammation, are complex processes and cover a wide range of spatial scales. The multiscale model of the airway have been developed combining the computational models at organ, tissue, and cellular levels. A model at the organ level was used to study behaviors of the airway during mechanical ventilation. Strain distributions in each layer of the airway were investigated using a model at the tissue level. The cellular inflammatory responses during mechanical ventilation were investigated through the cellular automata (CA) model incorporating all biophysical processes during inflammatory responses. The multiscale modeling framework started by obtaining airway displacements from the organ-level model. They were then transferred to the tissue-level model for determining the strain distributions in each airway layer. The strain levels in each layer were then transferred to the cellular-level model for inflammatory responses due to strain levels. The ratio of the number of damage cells to healthy cells was obtained through the cellular-level model. This ratio, in turn, modulated changes in the Young’s modulus of elasticity at the tissue and organ levels. The simulation results showed that high tidal volume (1400 cc) during mechanical ventilation can cause tissue injury due to high concentration of activated immune cells and low tidal volume during mechanical ventilation (700 cc) can prevent tissue injury during mechanical ventilation and can mitigate tissue injury from the high tidal volume ventilation. The multiscale model developed in this research could provide useful information about how mechanical ventilation contributes to airway inflammation so that a better strategy to ventilate patients can be developed.

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Yeung, Mei-yan, i 楊美恩. "Evidence-based guidelines on ventilator-associated pneumonia prevention for mechanically ventilated patients". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44626885.

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Parotto, Matteo. "Studio dei meccanismi coinvolti nel "ventilator-induced lung injury"". Doctoral thesis, Università degli studi di Padova, 2012. http://hdl.handle.net/11577/3422171.

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Introduction. Mechanical ventilation (MV) represented a fundamental step forward in the care of patients in both intensive care and anesthesia. Unfortunately, it can exacerbate, or even initiate, acute lung injury. Many mechanically ventilated patients with Acute Respiratory Distress Syndrome (ARDS) go on to develop pulmonary fibrosis. We hypothesized that the MV may contribute to the development of this fibrosis through different mechanisms. Materials and methods. In vitro. Human alveolar epithelial cells BEAS-2B were subjected to cyclic mechanical stretch for 24 or 48 hours, and then the expression of epithelial and mesenchymal markers was analyzed. In vivo. Mice C57 BL/6 were randomized to 4 treatments: healthy controls; inhalation of hydrochloric acid (HCl) inhalation of control solution followed 24 hours later by MV; inhalation of HCl followed 24 hours later by MV. Treated animals were then followed for periods of 3, 8 and 15 days after inhalation. We analyzed lung mechanics, lung histology, circulating fibrocytes, the quantities of hydroxyproline as well as the expression of epithelial and mesenchymal markers in the lungs. Results. In vitro. The cyclic mechanical stretch in BEAS-2B cells resulted a in reduction in the expression of epithelial markers cytokeratin 8, E-cadherin and pro-surfactant protein B (proSPB), and increased expression of TGF-β1 and β-catenin and of the mesenchymal markers α-SMA and vimentin A. In vivo. MV, alone or in combination with the inhalation of HCl, resulted in altered lung mechanics, an increase of hydroxyproline content and expression of TGF-β1, β-catenin and the mesenchymal markers α-SMA and vimentin A, and a decrease in the expression of the epithelial markers cytokeratin 8, E-cadherin and proSPB. The circulating fibrocytes count was not affected by MV. Histological examination showed increased pulmonary fibrosis in treated animals and potential epithelial-mesenchymal transition after inhalation of HCl followed by MV. Conclusions. Mechanical stress causes pulmonary fibrosis, and the phenomenon of epithelial-mesenchymal transition may play a role in this process. If the results of our work are confirmed, the modulation of the fibrotic response in patients who require MV may represent an important new therapeutic target to investigate.
Introduzione. La ventilazione meccanica (MV) ha rappresentato un fondamentale passo avanti nell’assistenza dei pazienti sia in terapia intensiva sia in anestesia. Purtroppo però essa può esacerbare, o addirittura iniziare, un danno polmonare acuto. Molti pazienti con Acute Respiratory Distress Sindrome (ARDS) ventilati meccanicamente sviluppano fibrosi polmonare. Abbiamo ipotizzato che la MV possa contribuire mediante diversi meccanismi allo sviluppo di tale fibrosi. Materiali e metodi. In vitro. Cellule epiteliali alveolari umane BEAS-2B sono state sottoposte ad allungamento meccanico ciclico per 24 o 48 ore, e quindi si è analizzata l’espressione di marcatori epiteliali e mesenchimali in esse. In vivo. Topi C57 Bl/6 sono stati randomizzati verso 4 trattamenti: controlli sani; inalazione di acido cloridrico (HCl); inalazione di soluzione di controllo seguita dopo 24 ore da MV; inalazione di HCl seguita dopo 24 ore da MV. Gli animali trattati sono stati quindi seguiti per periodi di 3, 8 e 15 giorni dopo l’inalazione. Si sono analizzate le meccaniche polmonari, l’istologia polmonare, i fibrociti circolanti, i quantitativi di idrossiprolina così come l’espressione di marcatori epiteliali e mesenchimali nei polmoni. Risultati. In vitro. L’allungamento meccanico ciclico ha determinato nelle cellule BEAS-2B una riduzione nell’espressione dei marcatori epiteliali citocheratina 8, E-caderina e pro-proteina del surfattante B (proSPB), ed un aumento dell’espressione di TGF-β1 e β-catenina e dei marcatori mesenchimali α-SMA e vimentina A. In vivo. La MV, da sola o in associazione all’inalazione di HCl, ha determinato alterate meccaniche polmonari, un aumento del contenuto di idrossiprolina e dell’espressione di TGF-β1 e β-catenina e dei marcatori mesenchimali α-SMA e vimentina A, ed una diminuita espressione dei marcatori epiteliali citocheratina 8, E-caderina e proSPB. I fibrociti circolanti non sono stati influenzati dalla MV. L’istologia polmonare ha mostrato aumentata fibrosi negli animali trattati e potenziale transizione epitelio-mesenchimale dopo inalazione di HCl seguita da MV. Conclusioni. Lo stress meccanico determina fibrosi polmonare, e il fenomeno della transizione epitelio-mesenchimale potrebbe giocare un ruolo in questo processo. Se i risultati del nostro lavoro saranno confermati, la modulazione della risposta fibrotica nei pazienti che necessitano di MV potrebbe rappresentare un nuovo, importante bersaglio terapeutico da investigare.

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Liu, Hui. "The application of alveolar microscope on alveolar mechanics of ventilator-induced lung injury". [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:25-opus-61847.

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Hedberg, Malin, i Roodsari Leila Tavallaey. ""Gör som ni brukar" : Intensivvårdssjuksköterskors uppfattning om urträning från ventilator". Thesis, Röda Korsets Högskola, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:rkh:diva-671.

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Bakgrund: För tidig eller för sen urträning från ventilator kan ge negativa konsekvenser för patienten, därför bör det identifieras när patientens tillstånd tillåter detta. Med anledning av det och att ansvaret för urträningen övergått mer från läkarna till sjuksköterskorna har det utvecklats hjälpmedel såsom evidensbaserade urträningsprotokoll. Dessa medför en mer samstämmig behandling och har också visat sig leda till kortare behandlingstid med ventilator. Olikheter i vårdpersonalens kunskap, utbildningsnivå, erfarenhet, ansvarsområden och hur organisationen ser ut påverkar hur urträningen genomförs. Syfte: Att beskriva intensivvårdssjuksköterskors uppfattning om urträning från ventilator. Metod: En empirisk fokusgruppintervjustudie med kvalitativ och deskriptiv ansats genomfördes. Antal deltagare var sex intensivvårdssjuksköterskor. Datamaterialet analyserades med kvalitativ innehållsanalys. Resultat: Det framkom tre huvudkategorier, Organisationen, Intensivvårdssjuksköterskan och Patienten samt fyra subkategorier, Rutiner, Samarbete, Kompetens och Omvårdnad. Slutsats: Det behövs en tydlig struktur i organisationen för att urträningsprocessen ska fungera tillfredsställande. Denna struktur kan skapas med rutiner, fungerande samarbete, tydlig kommunikation och hjälpmedel så som urträningsprotokoll. Urträningen för patienterna skulle underlättas, bli mer effektiv och leda till kortare behandlingstid. Klinisk betydelse: Studien kan bidra till diskussion om vilka förutsättningar som behövs för att bedriva en effektiv urträning utifrån god och säker evidensbaserad vård. Dessa förutsättningar kan bidra till ökad patientsäkerhet, kortare vårdtid och lägre vårdkostnader.
Background: Weaning onset should be initiated when the patient´s condition permits it, too early or late onset can have negative consequences for the patient. To help the nurse perform weaning, tools such as evidence-based weaning protocols have been developed and results in more consistent treatment shown to shortening duration of ventilator treatment. Differences between health profession, i.e. educational level, experience, responsibilities and organization structure, affect how the weaning is performed. Objective: To describe ICU nurses´ perception of ventilator weaning. Method: An empirical focus group study with a qualitative and descriptive approach was conducted. Six intensive care nurses were included. Data was analyzed using content analysis. Results: Three main categories were revealed, the Organization, the Intensive care nurse and the Patient along with four subcategories, Procedures, Collaboration, Competence and Nursing. Conclusion: For the weaning process to work satisfactorily a clear structure is needed. This can be created with routines, effective collaboration, clear communication and tools such as weaning protocols. For the patients weaning would be facilitated, become more efficient and shorten the duration of treatment. Clinical significance: The study may contribute to the discussion about the conditions needed to conduct effective weaning based on good and reliable evidence-based care. These conditions may contribute to increase patient safety, shorter hospital stay and lower health care costs.

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Carteaux, Guillaume. "Optimisation des interactions patient-ventilateur en ventilation assistée : intérêt des nouveaux algorithmes de ventilation". Thesis, Paris Est, 2015. http://www.theses.fr/2015PESC0027/document.

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En ventilation assistée, les interactions patient-ventilateur, qui sont associés au pronostic, dépendent pour partie des algorithmes de ventilation. Objectifs : Caractériser l'intérêt potentiel des nouveaux algorithmes de ventilation dans l'optimisation des interactions patient-ventilateur : 1) en ventilation invasive, deux modes et leurs algorithmes nous ont semblé novateurs et nous avons cherché à personnaliser l'assistance du ventilateur en fonction de l'effort respiratoire du patient au cours de ces modes proportionnels : ventilation assistée proportionnelle (PAV+) et ventilation assistée neurale (NAVA) ; 2) en ventilation non-invasive (VNI) nous avons évalué si les algorithmes VNI des ventilateurs de réanimation et des ventilateurs dédiés à la VNI diminuaient l'incidence des asynchronies patient-ventilateur. Méthodes : 1) En PAV+ nous avons décrit un moyen de recalculer le pic de pression musculaire réalisée par le patient à chaque inspiration à partir du gain réglé et de la pression des voies aériennes monitorée par le respirateur. Nous avons alors évalué la faisabilité clinique d'ajuster l'assistance en ciblant un intervalle jugé normal de pression musculaire. 2) Nous avons comparé une titration de l'assistance en NAVA et en aide inspiratoire (AI) en se basant sur les indices d'effort respiratoire. 3 et 4) En VNI, nous avons évalué l'incidence des asynchronies patient-ventilateur avec et sans l'utilisation d'algorithmes VNI : sur banc d'essai au cours de conditions expérimentales reproduisant la présence de fuites autour de l'interface ; en clinique chez des patients de réanimation. Résultats : En PAV+, ajuster le gain dans le but de cibler un effort respiratoire normal était faisable, simple et souvent suffisant pour ventiler les patients depuis le sevrage de la ventilation mécanique jusqu'à l'extubation. En NAVA, l'analyse des indices d'effort respiratoire a permis de préciser les bornes d'utilisation et de comparer les interactions patient-ventilateur avec l'AI dans des intervalles d'assistance semblables. En VNI, nos données pointaient l'hétérogénéité des algorithmes VNI sur les ventilateurs de réanimation et retrouvaient une meilleure synchronisation patient-ventilateur avec l'utilisation de ventilateurs dédiés à la VNI pour des qualités de pressurisation par ailleurs identiques. Conclusions : En ventilation invasive, personnaliser l'assistance des modes proportionnels optimise les interactions patient-ventilateur et il est possible de cibler une zone d'effort respiratoire normale en PAV+. En VNI, les ventilateurs dédiés améliorent la synchronisation patient-ventilateur plus encore que les algorithmes VNI sur les ventilateurs de réanimation, dont l'efficacité varie grandement selon le ventilateur considéré
During assisted mechanical ventilation, patient-ventilator interactions, which are associated with outcome, partly depend on ventilation algorithms.Objectives: : 1) during invasive mechanical ventilation, two modes offered real innovations and we wanted to assess whether the assistance could be customized depending on the patient's respiratory effort during proportional ventilatory modes: proportional assist ventilation with load-adjustable gain factors (PAV+) and neurally adjusted ventilator assist (NAVA); 2) during noninvasive ventilation (NIV): to assess whether NIV algorithms implemented on ICU and dedicated NIV ventilators decrease the incidence of patient-ventilator asynchrony.Methods: 1) In PAV+ we described a way to calculate the muscle pressure value from the values of both the gain adjusted by the clinician and the airway pressure. We then assessed the clinical feasibility of adjusting the gain with the goal of maintaining the muscle pressure within a normal range. 2) We compared titration of assistance between neurally adjusted ventilator assist (NAVA) and pressure support ventilation (PSV) based on respiratory effort indices. During NIV, we assessed the incidence of patient-ventilator asynchrony with and without the use of NIV algorithms: 1) using a bench model; 2) and in the clinical settings.Results: During PAV+, adjusting the gain with the goal of targeting a normal range of respiratory effort was feasible, simple, and most often sufficient to ventilate patients from the onset of partial ventilatory support until extubation. During NAVA, the analysis of respiratory effort indices allowed us to precise the boundaries within which the NAVA level should be adjusted and to compare patient-ventilator interactions with PSV within similar ranges of assistance. During NIV, our data stressed the heterogeneity of NIV algorithms implemented on ICU ventilators. We therefore reported that dedicated NIV ventilators allowed better patient-ventilator synchronization than ICU ventilators, even with their NIV algorithms engaged.Conclusions: During invasive mechanical ventilation, customizing the assistance during proportional ventilatory modes with the goal of targeting a normal range of respiratory effort optimizes patient-ventilator interactions and is feasible with PAV+. During NIV, dedicated NIV ventilators allow better patient-ventilator synchrony than ICU ventilators, even with their NIV algorithm engaged. ICU ventilators' NIV algorithms efficiency is however highly variable among ventilators

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Carroll, Nadine. "The use of protriptyline or nocturnal mechanical ventilatory support for respiratory failure in chronic bronchitis and emphysema". Thesis, University of Liverpool, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235493.

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PUTIGNANO, OSCAR. "Development of a Cherenkov based diagnostic for gamma-rays from fusion plasmas and advanced medical applications". Doctoral thesis, Università degli Studi di Milano-Bicocca, 2023. https://hdl.handle.net/10281/402358.

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Lo scopo di questa tesi, iniziata a novembre 2019, è lo sviluppo di un rivelatore Cherenkov per misurare i raggi gamma da 17 MeV emessi dalla reazione di fusione D-T. Con l'espandersi della pandemia da COVID-19 nel nord Italia, a metà febbraio 2020, è divenuto evidente che il piano iniziale del mio lavoro di tesi dovesse essere fortemente cambiato, a causa della cancellazione delle attività sperimentali che avrebbero dovuto svolgersi nei laboratori UNIMIB/CNR a Milano e al Joint European Torus nel Regno Unito. In accordo con i miei tutor ho iniziato, insieme ad altri ricercatori, a lavorare su base volontaria ad un progetto denominato Mechanical Ventilator Milano (MVM). Il progetto MVM ha coinvolto un gruppo internazionale di più di 150 scienziati e ha prodotto in meno di tre mesi un ventilatore meccanico certificato dalla Food and Drugs Administration per uso su pazienti affetti da COVID-19 in terapia intensiva. L'attività su MVM ha portato, circa un anno dopo, allo sviluppo di un nuovo sensore di ossigeno veloce per applicazioni mediche. Il sensore è in grado di misurare il consumo di ossigeno di un individuo in tempo reale e durante un singolo respiro. La tesi è divisa in tre parti. La prima parte si concentra sullo sviluppo di un contatore di raggi gamma ottimizzato per la misura della potenza di fusione in un reattore a confinamento magnetico. Il gruppo di ricerca in cui mi sono inserito sta sviluppando un metodo innovativo per la misura della potenza prodotta dalle reazioni di fusione basato sulla rivelazione dei raggi gamma da 17 MeV prodotti durante la reazione D+T->5He*. Tipicamente il nucleo di 5He* decade emettendo una particella alfa e un neutrone, ma può anche diseccitarsi sullo stato fondamentale dell'5He, prima che questo si disintegri in una particella alfa e un neutrone, con una probabilità di 10^-5. Questi raggi gamma sono stati misurati al JET nella campagna DT appena conclusa con uno spettrometro gamma basato su un cristallo di LaBr3 e una acquisizione dati digitale veloce. Poiché l'efficienza ai raggi gamma e ai neutroni del LaBr3 è simile, è stato necessario usare un attentatore neutronico dedicato per osservare il debole segnale dovuto ai raggi gamma. Per superare i problemi dovuti alla sensibilità del LaBr3 ai neutroni ho progettato un rivelatore gamma a gas ottimizzato per funzionare in presenza di un intenso fondo neutronico. il rivelatore è basato sull'effetto Cherenkov e le simulazioni indicano che è 10^6 volte più sensibile ai raggi gamma che ai neutroni. Il prossimo passo sarà quello di costruire un prototipo del rivelatore per validare le simulazioni e provarlo su una sorgente di neutroni D-T. La seconda parte della tesi descrive lo sviluppo del sensore IFOx, un sensore di ossigeno ultra-veloce che può essere utilizzato per l'analisi polmonare. Poiché il principio di funzionamento del sensore è simile a quello di uno scintillatore, è un esempio di trasferimento di conoscenze dal campo delle diagnostiche nucleari ad applicazioni diverse. Il prototipo del sensore è caratterizzato da un'eccellente risposta temporale ed è stato utilizzato per misurare la Capacità Funzionale Residua in volontari sani. I risultati eccellenti del test sui volontari sani hanno aperto la via per uno studio clinico su pazienti intubati, durante il quale il sensore verrà integrato con un ventilatore polmonare. L'ultima parte della tesi riguarda MVM e descrive la progettazione di un ventilatore che necessita poche parti e che può essere costruito in tempi brevi anche durante una interruzione della catena di approvvigionamento dei materiali. Ho contribuito al progetto grazie alla mia esperienza sui sistemi gas e sui controlli software in tempo reale, e ho partecipato alle misure necessarie ad ottenere la calibrazione. I risultati principali che hanno portato alla certificazione per uso umano da parte della Comunità Europea sono descritti nella tesi.
Aim of this thesis, begun in November 2019, is the development of an innovative Cerenkov detector for measurements of 17 MeV gamma-rays emitted by the D-T fusion reaction in an intense neutron field. With the spread of the COVID-19 pandemics in Northern Italy in February 2020, it became clear that the original program planned for my PhD work had to be significantly changed, since experimental activities to be carried out in the UNIMIB/CNR laboratories in Milan and at the Joint European Torus in the UK had to be cancelled. In agreement with my tutors I volunteered together with other scientists to contribute to a project called Mechanical Ventilator Milan (MVM). The MVM project involved an international team of more than 150 scientists and has produced over the very short period of less than three months a mechanical ventilator approved by the American Food and Drug Administration for use at the intensive care unit of hospitals to treat patients affected by COVID-19. The activities of the MVM project led to the development of a new fast oxygen sensor for medical application, about one year later. The sensor measures the oxygen consumption in real time during a single breath. The thesis is organized in three parts. The first part is focused on the development of a gamma-ray counter optimized for the measurement of the D-T fusion power produced in a magnetic confinement fusion device. The research team I have joined is developing a novel technique for the measurement of DT fusion power in a magnetic confinement device based on the detection of 17 MeV gamma-rays also produced by the D+T->5He* reaction. The 5He* nucleus promptly decays usually emitting an alpha particle and a neutron, but it may de-excite to the ground level emitting a gamma-ray with a probability of the order of 10^-5. These gamma-rays have been detected in the recent DT campaign at JET with a gamma spectrometer based on LaBr3 and a fast digital data acquisition. Since the efficiency of the scintillator to high energy gamma-rays and neutrons are comparable, the use of a dedicated LiH based neutron attenuator to observe the weak gamma-ray signal is needed. To overcome the limitations posed by the sensitivity of LaBr3 detectors to neutrons, I designed a gamma-ray gas detector optimized to work in the presence of an intense neutron field. The detector is based on the Cherenkov effect and simulations indicate that it is 10^6 times more sensitive to gamma-rays than to neutrons. The next step would be to build a prototype of the detector to validate the simulation results and to test it on a D-T neutron source. The second part of the thesis describes the design and build of the IFOx sensor, an ultra-fast oxygen sensor that can be used for lung analysis by working in the so called mainstream configuration. Since the working principle of the IFOx sensor somewhat resembles the one of a scintillator detector, this is an example of knowledge transfer from nuclear diagnostics to a different application. The prototype that was built features excellence time response and was used in a trial study on healthy volunteers to measure the Functional Residual Capacity. The excellent results of the trial study on healthy volunteers has opened up the possibility to carry out a clinical study on intensive care unit patients in the near future, by integrating the oxygen sensor with mechanical ventilators. The last part of the thesis is about the MVM project and describes the ventilator design aimed to the production of a ventilator composed of a few parts so that it can be rapidly built on large scales even during the disruption of the components supply chain. I was able to contribute to the project thanks to my knowledge of gas systems, advanced real time controls, and I participated in the measurement required for the certification. The key results that led to a full certification for usage on patient by the European Commission are also described in this work.

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Baudin, Florent. "Ventilation mécanique dans les pathologies obstructives de l'enfant : physiopathologie des interventions ventilatoires et non ventilatoires". Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1056/document.

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Les pathologies respiratoires obstructives de l’enfant (asthme et broncho-alvéolites) sont l’une des principales causes d’admission en réanimation pédiatrique. Depuis plusieurs années, des progrès ont été faits pour réduire l’invasivité des soins se traduisant par une réduction de la morbidité. L’objectif de ce travail de thèse est de s’appuyer sur des mécanismes physiopathologiques pour proposer des stratégies d’optimisation ventilatoire et non ventilatoire chez ces enfants. Nous avons évalué l’impact du décubitus ventral couplé à la ventilation non invasive chez les nourrissons atteints de bronchiolite grave. Le décubitus ventral permet de réduire significativement l’effort inspiratoire et d’améliorer le couplage électromécanique du diaphragme. Ensuite nous avons évalué la « neurally adjusted ventilatory assist » (NAVA) qui est un mode ventilatoire proportionnel basé sur l’activité électrique du diaphragme. Nous avons démontré que la NAVA améliorait la synchronisation patient-respirateur et réduisait le travail respiratoire en comparaison à la « nasal continuous positive airway pressure » (nCPAP). Enfin, dans la pathologie asthmatique nous avons également décrit la faisabilité du haut débit nasal dans cette population. Ces stratégies nécessitent maintenant d’être validées sur des critères cliniques et feront l’objet de deux études multicentriques randomisées
Obstructive lung disease in children (asthma and bronchiolitis) are one of the main causes of admission to pediatric intensive care units. For several years, progress has been made to reduce the invasiveness of care resulting in a decrease in associated morbidity. The main objective of the thesis was to propose new ventilatory and non-ventilatory strategies based on physiopathology to optimize the care of such children.In children with severe bronchiolitis we evaluated the impact of prone position associated with non-invasive ventilation. The prone position decreases significantly the inspiratory work of breathing and improves the neuromechanical efficiency of the diaphragm. We also evaluated the effect of neurally adjusted ventilatory assist (NAVA) that is a proportional ventilatory mode based on the electrical activity of the diaphragm. We demonstrated that NAVA improved the patient-ventilator interactions and decrease the work of breathing in comparison with nasal continuous positive airway pressure (nCPAP). We also evaluated the feasibility of high flow nasal cannula as a respiratory support in children with severe asthma attack. These strategies need now to be validated on clinical outcomes and are the subject of two ongoing multicenter randomized trials

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Turowski, Paweł [Verfasser]. "Molecular mechanisms of ventilator-induced acute kidney injury : Mechanical ventilation can modulate neutrophil recruitment to the kidney / Paweł Turowski". Gießen : Universitätsbibliothek, 2012. http://d-nb.info/1064838820/34.

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Herbert, Joseph Ames. "The molecular and mechanical mechanisms of the age-associated increase in the severity of experimental ventilator induced lung injury". VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4478.

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Abstract Background The majority of patients requiring mechanical ventilation are over the age of 65 and advanced age is known to increase the severity of ventilator-induced lung injury (VILI) and mortality. However, the mechanisms which predispose aging ventilator patients to increased mortality rates are not fully understood. Pulmonary edema is a hallmark of VILI and the severity of edema increases with age. Ventilation with conservative fluid management decreases mortality rates in acute respiratory distress (ARDS) patients, but has not been investigated in VILI. We hypothesized that age-associated increases in pulmonary edema promote age-related increases in ventilator-associated mortality. Endoplasmic reticulum (ER) stress can disrupt cellular functions and plays a key role in many disease states. The severity of ER stress also increases with age. We hypothesized that age-associated increases in ER stress also increase in the severity of VILI. Finally, serum Vitamin C (VitC) levels also decrease with age. VitC treatments have been shown to decrease mortality rates in murine models of ARDS by and attenuate pulmonary edema. We hypothesize that VitC treatments will attenuate ventilator induced pulmonary edema in our aged murine subjects. Methods Mechanical Ventilation: Young and old mice were mechanically ventilated with either high tidal volume (HVT) or low tidal volume (LVT) for with either liberal or conservative fluid support. One group received VitC treatment prior to ventilation. Cell Stretch: Alveolar epithelial cells (ATIIs) from young and old mice were harvested, cultured, and mechanically stretched. Treatment groups received ER stress inhibitor 4-PBA. Results Both advanced age and HVT ventilation significantly increased inflammation, injury, and decreased survival rates. Conservative fluid support significantly diminished pulmonary edema decreased mortality rates. VitC treatments significantly decreased pulmonary edema and improved pulmonary mechanics. Mechanical stretch promoted ER Stress and upregulated proinflammatory gene expression and secretion in aged ATIIs. ER stress inhibition attenuated all of these effects. Conclusion Conservative fluid management alone attenuated age-associated increases in ventilator-associated mortality. VitC treatments decreased pulmonary edema and partially restore pulmonary mechanics in old mice ventilated with HVT. ER stress inhibition decreased stretch induced proinflammatory gene expression and protein secretion in aged mechanically stretched ATII cells.

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Lattuada, Marco. "Effect of Ventilatory Support on Abdominal Fluid Balance in a Sepsis Model". Doctoral thesis, Uppsala universitet, Klinisk fysiologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-207218.

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In patients affected by acute respiratory failure or acute respiratory distress syndrome (ARDS) the leading cause of death is failure of different vital organs other than the lungs, so called multiple organ dysfunction syndrome (MODS). The abdominal organs have a crucial role in the pathogenesis of this syndrome. There is a lack of knowledge regarding the mechanisms by which mechanical ventilation can affect the abdominal compartment. One hypothesis is that mechanical ventilation can interfere with abdominal fluid balance causing edema and inflammation. We addressed the question whether different levels of ventilatory support (mechanical ventilation with different levels of positive end-expiratory pressure, PEEP, and spontaneous breathing with or without PEEP) can influence abdominal edema and inflammation in both healthy and endotoxin-exposed animals. The effect on lymphatic drainage from the abdomen exerted by different degrees of ventilatory support was evaluated (paper I). We demonstrated that endotoxin increases abdominal lymph production, that PEEP and mechanical ventilation increase lymph production but also impede lymphatic drainage; spontaneous breathing improves lymphatic drainage from the abdomen. By adapting a non-invasive nuclear medicine imaging technique and validating it (paper II), we have been able to evaluate extravascular fluid accumulation (edema formation) in the abdomen over time (paper III) demonstrating that edema increases during endotoxemia, mimicking a sepsis-like condition, and that spontaneous breathing, compared to mechanical ventilation, reduces extravascular fluid. Pro-inflammatory cytokines TNF-α and IL-6 in intestinal biopsies are reduced during spontaneous breathing compared to mechanical ventilation. Abdominal edema results in increased intra-abdominal pressure (IAP): in paper IV we analyzed the effect of increased intra-abdominal pressure on the respiratory system. Pulmonary shunt fraction increased with high IAP both in healthy and LPS animals, resulting in decreased level of oxygenation. These changes are only partially reversible by reducing IAP. In conclusion, mechanical ventilation is a life-saving tool but the possible side effect at the extra-pulmonary level should be considered, and the introduction of some degree of spontaneous breathing when clinically possible is a suggested choice.

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MacDonald, Ian. "Burial mechanics of the Pacific sandfish| The role of the ventilatory pump and physical constraints on the behavior". Thesis, Northern Arizona University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10004157.

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Burial is an important life history strategy employed by benthic fishes that has not been fully explored in its diversity by the biomechanical literature. This thesis explores the mechanism by which the Pacific sandfish buries as well as the physical limitations of the behavior. We first investigate the role of the ventilatory pump in the burial behavior of sandfish by using high-speed videography, dye, and digital particle image velocimetry (DPIV). We determined that sandfish employ a modification of the ventilatory pump, which is used repeatedly to fluidize the substrate ventral to the head. This modification of the ventilatory pump should reduce the energetic costs associated with burial as it decreases the cost of transport typically associated with ‘shoveling’ substrate. Second, we investigate the physical limitations that are caused by the reliance on the ventilatory pump to fluidize substrate. We used sand beds of varying grain sizes, and therefore varied the minimum velocities of fluidization, to determine how sandfish respond variation in substrata. We determined that sandfish can bury in grains smaller than 1.00mm in diameter but were unable to bury in any substrate larger than 1.00mm. We also determined that there was an increase in the time it took sandfish to bury in those substrates smaller than 1.00mm as grain size increased. There was no change in the frequency of the behavior, however, suggesting that sandfish have very little ability to bury in larger substrates. We also determined that it is probably not the absolute velocity produced by the opercular jet that determines burial success, but the ability burying behavior to maintain the sand’s momentum during the expansive phase that occurs between bouts of opercular jetting.

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Micski, Erik, i Ulrika Ottosson. "Calculation of Tidal Volume based on EMG-activity of the Diaphragm". Thesis, KTH, Skolan för teknik och hälsa (STH), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210547.

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The objective of the thesis was to evaluate the possibility to calculate the unloading distribution between a ventilator and a patient using a new mathematical modelling of the breathing patterns. The modelling used today is considered to lack sufficient precision for clinical use, and is a somewhat simplified model. To evaluate the possibility of a new model, a volunteer test was carried out - recording data such as Edi, pressure, volume and flow. Using this data, and by using a more complex model, tidal volume was estimated and compared to the measured data. The results did not imply any improvement compared to the simpler model regarding the accuracy and the variability. However, more work should be done in this area, as time deficiency prevented further analysis.

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Silva, Alexandre Rodrigues da. "Hardware de ventilador pulmonar". Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/3/3139/tde-03052012-121527/.

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Este trabalho visou mostrar o desenvolvimento de um ventilador pulmonar mecânico, focando principalmente na parte de hardware necessária para que este equipamento pudesse funcionar. Ventilação mecânica é a modalidade da medicina mais importante no cuidado a pacientes criticamente enfermos. O ventilador é um equipamento utilizado principalmente em unidades de terapia intensiva, que basicamente coloca uma mistura de ar e oxigênio para dentro do pulmão de um paciente incapacitado de fazer isto naturalmente, quer seja por força de uma doença que o impossibilita de fazê-lo, ou por uma cirurgia, a qual impossibilitou o movimento do músculo do diafragma para que o ar entrasse no pulmão naturalmente. Este projeto cobriu uma descrição abrangente sobre este ventilador, sua transformação de ar comprimido e oxigênio provenientes de um cilindro em uma mistura controlada de fluxos que entra no pulmão para a inspiração de um volume, ou para atingir uma pressão determinada, e a saída desta mistura, mantendo no pulmão uma pressão também controlada. Foi desenvolvido um protótipo de hardware e firmware para este aparelho, e o intuito foi mostrar o processo de transformação da ideia inicial e as necessidades de projeto em um aparelho testado e certificado para uso no mercado.
This work aimed to present the development of a pulmonary mechanical ventilator, mainly focusing on the hardware part needed in order for this device to work. Mechanical ventilation is the most important medical mode concerning the care of patients that are critically ill. The ventilator is a device very much used in intensive care units (ICUs), and it basically delivers an air and oxygen mixture to the patients lungs that is normally unable to do so naturally, either because the patient is seriously ill that prevents him/her to do so, or due to surgery, in this case prevented the movement of the diaphragm muscle so the air could be naturally delivered to the lung. This work covered a comprehensive description about this ventilator, its transformation of compressed air and oxygen coming from a cylinder in a controlled mixture of flows that enters the lung for the inspiration of a volume, or to achieve a determined pressure, and the output of this mixture, maintaining a controlled pressure in the lung too. A hardware and firmware prototype was developed for this device. The aim was to show the transformation process from the main idea and the need for a project of a tested and certified device to be used in the market.

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Mercene, Tedgardo Pacal. "Improving Quality of Care for Mechanically Ventilated Patients in Long Term Care Through Full Compliance with the Ventilator Bundle Protocol". ScholarWorks, 2016. https://scholarworks.waldenu.edu/dissertations/2853.

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One of the most common methods used by healthcare professionals in the ventilator unit to reduce morbidity and mortality due to ventilator-associated pneumonia (VAP) is a group of best practices known as the ventilator bundle. However, evidence from the literature shows that all its components must be in compliance if the bundle is to be effective. The purpose of this quality improvement project was to investigate the level of compliance with the different components of the ventilator bundle protocol at the study site's nursing home and rehabilitation center, as well as to improve compliance with the bundle protocol at the site. In-depth interviews were conducted with 15 nurses from the site on their knowledge of VAP and the ventilator bundle. Those narratives were analyzed using grounded theory analysis, with the data demonstrating poor understanding of and compliance with the ventilator bundle. Posters were then mounted throughout the facility on the importance of complying fully with the bundle, using information gleaned from the interview analysis. Evidence from this project could yield a quality improvement model for long-term-care facilities and ventilator units in particular. The goal was to improve nursing staff's knowledge about VAP and the ventilator bundle, reduce VAP morbidity and mortality, and ensure that mechanically ventilated patients receive the best quality of care.

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Harvey, Jessica C. "The Effects of Fish Oil (EPA+DHA) on Chronic Ventilator Patients in a Long Term Acute Care Setting: A Randomized Control Trial". University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1307125476.

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Marjanovic, Nicolas. "Approche globale du support ventilatoire en médecine d'urgence". Thesis, Poitiers, 2020. http://theses.univ-poitiers.fr/64158/2020-Marjanovic-Nicolas-These.

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L’insuffisance respiratoire aiguë est un motif fréquent de consultation dans un service d’urgences. Le traitement de première intention repose sur l’oxygénothérapie conventionnelle. En cas d’échec ou d’emblée en cas d’urgence vitale immédiate, le recours à un support ventilatoire devient nécessaire. Les supports ventilatoires englobent l’oxygénothérapie à haut-débit nasal humidifiée (OHD) et la ventilation mécanique qui peut être invasive ou non-invasive. Les données concernant l’intérêt du support ventilatoire en médecine d’urgence sont issues pour l’essentiel de travaux conduits en réanimation, et une approche globale de leur place en médecine d’urgence n’a jamais été réalisé.L’objectif de ce travail est de proposer une évaluation globale du support ventilatoire en médecine d’urgence, en analysant l’intérêt de l’OHD, d’introduction récente aux urgences, et la pratique aux urgences de la ventilation mécanique non-invasive et invasive.Nous avons dans un premier temps évalué les effets cliniques et gazométriques de l’OHD au cours de l’insuffisance respiratoire aiguë hypoxémique de novo, puis au cours de l’insuffisance respiratoire aiguë hypercapnique secondaire à un OAP cardiogénique, aux travers de deux études prospectives. Puis, nous avons réalisé une compilation des données de l’ensemble des études prospectives réalisés aux urgences pour déterminé si la mise en place précoce de l’OHD au cours des détresses respiratoires aiguës sans cause spécifique était susceptible d’améliorer le devenir des patients. Nous avons constaté qu’une mise en place précoce de l’OHD, dès l’admission du patient aux urgences, était associée à une amélioration des paramètres cliniques et gazométriques en cas d’insuffisance respiratoire aiguë de novo comparativement à l’oxygénothérapie conventionnelle, et de manière similaire à la ventilation non-invasive en cas d’insuffisance respiratoire aiguë hypercapnique secondaire à un OAP. En revanche, au cours des détresses respiratoires aiguës admises aux urgences, quelle qu’en soit la cause, l’OHD n’a pas été associé à une diminution au recours à la ventilation mécanique, ni à une diminution de la mortalité.Parallèlement, nous avons réalisé une évaluation des pratiques de la ventilation mécanique aux urgences, en analysant, indépendamment de l’indication de la ventilation mécanique, trois déterminants susceptibles d’influer le pronostic des patients. Nous avons dans un premier temps conduit un banc d’essai de l’ensemble des ventilateurs mécaniques de médecine d’urgence commercialisés en Europe et en Amérique du Nord pour évaluer leur performance et leur utilisabilité aux travers de deux études. Puis, nous avons réalisé une évaluation des pratiques de la ventilation mécanique, et mesuré l’association entre les paramètres réglés (notamment la ventilation à faible volume) et le pronostic du patient. Nous avons mis en évidence que les ventilateurs de médecine d’urgence récents ont une performance technique proche des ventilateurs de réanimation en raison des évolutions technologiques et de l’émergence des ventilateurs à turbine. L’augmentation de leurs performances et de leur complexité n’a pas été associée à une dégradation de leur utilisabilité. Enfin, dans les 6 services d’urgences participants, la majorité des patients ont bénéficié d’une ventilation mécanique à faible volume courant (entre 6 et 8 mL/kg de poids idéal théorique), répondant ainsi aux recommandations des sociétés savantes. En revanche, une ventilation à faible volume courant n’a pas été associée à une diminution de l’incidence du syndrome de détresse respiratoire aigu ou une diminution du taux de mortalité.Ces études permettent une évaluation globale du support ventilatoire aux urgences, intégrant la ventilation mécanique invasive et non-invasive, par son approche clinique et technologique, et un traitement émergent, l’OHD, par son impact clinique, gazométrique et pronostique aux urgences
Acute respiratory failure is a common complaint of patients visiting the Emergency Department and conventional oxygen therapy is its first-line treatment. Ventilatory support is required when nasal oxygen therapy is not enough or as a first-line treatment in the most severe cases. Ventilatory supports include high-flow and humidified nasal cannula oxygen (HNFO) and mechanical ventilation. Data assessing their values in Emergency Departments (EDs) mainly come from research conducted in Intensive Care Units. In addition, a comprehensive approach of their application and their results in Emergency Departments has never been conducted.The aim of this research is to provide a comprehensive assessment of ventilatory supports in EDs by assessing the place of HFNO, introducing recently in this setting, and the practice of noninvasive and invasive mechanical ventilation in EDs. We assessed first the clinical and biological impact of HFNO in patients admitting to an ED for de novo acute hypoxemic respiratory failure, then in patients admitting for acute hypercapnic respiratory failure secondary to acute heart failure, through two prospective studies. In addition, we provided a matching of data issued from all prospective trials conducted in the EDs. We aimed to determine if early application of HFNO in patients with acute respiratory failure improves outcome. We found HFNO applied early was associated with an improvement in clinical and biological patterns in patients admitted for de novo acute hypoxemic respiratory failure, and similarly in patients admitted for acute hypercapnic respiratory failure due to acute heart failure. However, HFNO was not associated with a reduction of mechanical ventilation requirements or in mortality. In addition, we assessed mechanical ventilation in the ED by analysing three determinants that may influence patient’s outcome. First, we conducted a large bench test assessing performance and usability of all emergency ventilators marketed in Europe or North America and assessing through two distinct studies. Then, we assessed the mechanical ventilation practice in six French EDs and measured the association between mechanical ventilation settings and patients’ outcome. Performance of recent emergency ventilator were closes to ICU ventilators due to high technological improvements in the last decades. These improvements were associated with an increase of their complexity without impairment of their usability. Finally, in six French EDs, most of the patients were treated with a low tidal volume (between 6 and 8 mL/kg of predicted body weight) as recommend by scientific societies. However, a low tidal volume strategy was not associated with a reduction in the acute respiratory distress incidence as well as in mortality. These studies provided a comprehensive assessment of the ventilator support in the ED, including invasive and noninvasive ventilation, through a clinical and technological approach, and an emerging treatment, HFNO, by its clinical, biological and prognostic impact

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Aguirre, Bermeo Hernán Marcelo. "Efectos fisiológicos de diferentes estrategias ventilatorias empleadas en pacientes con insuficiencia respiratoria aguda severa". Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/664280.

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Los estudios realizados en la presente tesis están alineadas en determinar los efectos fisiológicos de dos estrategias utilizadas en pacientes en ventilación mecánica con insuficiencia respiratoria aguda severa. Las estrategias analizadas son habitualmente utilizadas en estos pacientes. El primer estudio presentado es sobre el alargamiento de la pausa inspiratoria. En este estudio se ha confirmado que el alargamiento de la pausa inspiratoria disminuye significativamente el espacio muerto y la PaCO2. Con este estudio, se proporciona una aplicación clínica de esta estrategia, ya que, la disminución de la PaCO2 permite disminuir el volumen corriente administrado y ayudar a la ventilación protectiva. El segundo estudio presentado es sobre la variación de los volúmenes pulmonares y el strain (deformación del tejido pulmonar causado por el cambio de volumen) con el cambio de posición de supino a prono. Este estudio ha permitido demostrar que los volúmenes pulmonares aumentan significativamente en la posición prono y disminuye significativamente el strain dinámico sobre el tejido pulmonar. Estos hallazgos pueden explicar la mejoría de los resultados clínicos con el uso de la posición prono en pacientes con síndrome de distres respiratorio agudo grave. La relativa sencillez e inocuidad de las estrategias estudiadas facilita su aplicación en el manejo clínico diario de estos pacientes y la información encontrada puede servir de base para futuros estudios y ampliar su uso en otro tipo de pacientes y patologías.
The studies described in this thesis are about the physiological effects of two common strategies that are used in mechanically ventilated patients with acute severe respiratory failure. The first study was about the prolongation of inspiratory pause. This study confirmed that the prolongation of inspiratory pause significantly decreased dead space and PaCO2. Indeed, this study provides a clinical application of this strategy, because the decrease of the PaCO2 allows a significant decrease of tidal volume and helps to set the protective ventilation. The second study analysed the variation of lung volumes and strain with the change from supine position to prone position. This study showed a significant increase in lung volumes and a significant decrease of strain in prone position. These findings could explain the improvement of outcomes with prone position in severe acute respiratory distress syndrome patients. The relative simplicity and safety of these strategies facilitates its application at the bedside. These data could form the basis for future studies in other types of patients and pathologies.

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Pastore, C. V. "VENTILAZIONE MECCANICA E VOLUTRAUMA: STUDIO IN VIVO IN UN MODELLO SUINO". Doctoral thesis, Università degli Studi di Milano, 2010. http://hdl.handle.net/2434/150177.

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Mechanical ventilation is an essential support for patients with acute lung pathologies, such as acute respiratory distress syndrome and acute lung injury, and it is generally applied in chirurgical practice. Specialists are however aware that, despite of its “life saving” role, this practice presents several negative side effects. Recently one of the most serious negative effects of mechanical ventilation, called Ventilatory Induced Lung Injury (VILI), has been detected and better analysed. This syndrome, initially associated with barotrauma, has been recently defined as volutrauma, meaning a damage of lung parenchyma caused by mechanical stress deriving from overdistension induced by high tidal volumes (VT). The aim of the present study was to evaluate the onset of ventilatory induced lung injury in a clinically relevant, validated and well-studied model, which closely mimics the human physiology and the ventilator setting currently used in the clinical arena. The study was performed using 18 pigs were involved, divided into three groups (n=6): two groups were mechanically ventilated (VT 20 ml/kg and 8 ml/kg), and one group was spontaneously breathing (SB). The duration of the experiments was 240 minutes. Hemogasanalysis and all main respiratory and circulatory parameters were detected every 30 minutes. Metalloproteinases 2 and 9 expression and activation and ET-1 levels were observed in the bronchoalveolar lavage fluid. At the end of the experiment, the animals were sacrificed and autoptic samples of lung, kidney and liver for histological and zymographic analysis were obtained. The results showed serious alterations of lung mechanics and structure induced by high VT, although the protective strategies as low VT were not immune from negative side effects. Respiratory function worsening was observed in spontaneously breathing subjects, too. Therefore, our study demonstrates that, both animals undergoing mechanical ventilation with high volumes and non-assisted breathing animals develop a massive lung edema, as revealed by extra-vascular lung water values. As expected, the alveolar over-distension induced ultrastructural cellular abnormalities only in animals subjected to high VT and not in those where lung distension was limited, as in our VT8 group, or absent, as in SB group. Our data show irrefutably that the severe edema formation noticed in spontaneously breathing animals was clearly related to the increase in pulmonary arterial pressure, which induced the extravasation of fluid into lung parenchyma. Moreover, we have evaluated the changes in lung mechanics and metalloproteinases production and activation in three different types of lung damages evoked by mechanical, hypoxic and septic stress. Under that, 24 pigs were studied, randomly divided into four groups (n=6): control group (pigs spontaneously breathing), mechanical stress group (pigs ventilated with high VT), hypoxic group (pigs inhaled with an hypoxic gas mixture), septic group (pigs i.v. infused with E.coli LPS). All the animals were studied for 240 minutes. Hemogasanalysis and main respiratory and circulatory parameters were detected every 20 minutes. At the end of the experiment, subjects were sacrificed and autoptic samples of lung for histological and zymographic analysis were obtained. The changes in physiological parameters were in line with morphological lung alterations. Zymographic analysis showed a strong activation of MMP-2 but no activation of MMP-9 in control, mechanical and hypoxic stress groups. The septic stress group has reflected a specular situation with activation of MMP-9 and low levels of MMP-2, which was present only in the inactivated form. The present study has underlined an acute modulation of MMPs in lung tissues and MMPs different behaviour facing different stimulations. In conclusion, it is clear that mechanical ventilation strategies profoundly affects lung parenchyma integrity and functionality, and the choice of a ventilation strategy that avoids these damages, ensuring at the same time an appropriate exchange of gases, is strongly encouraged.

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Rozé, Hadrien. "Activité électrique diaphragmatique au cours du sevrage ventilatoire après insuffisance respiratoire aigue". Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0293/document.

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Le contrôle de la ventilation procède d’une interaction complexe entre des efférences centrales à destination des groupes musculaires ventilatoires et des afférences ventilatoires provenant de mécano et de chémorécepteurs. Cette commande de la ventilation s’adapte en permanence aux besoins ventilatoires. L’activation électrique du diaphragme (EAdi) informe sur la commande ventilatoire, la charge des muscles respiratoires, la synchronie patient-ventilateur et l’efficacité de la ventilation des patients de réanimation. L’utilisation inadaptée d’un mode deventilation spontanée avec une sur ou sous-assistance peut entrainer des dysfonctions diaphragmatiques, des lésions alvéolaires et des asynchronies. La première étude a permis de cibler l’assistance du mode NAVA en fonction de l’EAdi enregistrée lors d’un échec de test de sevrage. Nous avons observé une augmentation quotidienne de cette EAdi au cours du sevrage jusqu’à l’extubation. La deuxième étude a montré que cette augmentation n’est pas associée à une modification de l’efficacité neuro-ventilatoire lors du test de sevrage, possiblement en rapport avec l’inhibition d’une sédation résiduelle. La troisième étude a montré l’importance de l’inhibition de cette sédation résiduelle par midazolam sur l’EAdi et le volume courant au début du sevrage ainsi que la corrélation qui existe entre les deux. Une dernière étude a montré l’absence d’augmentation du volume courant sous NAVA chez des patients transplantés pulmonaires aux poumons dénervés sans réflexe de Herring Breuer par rapport à un groupe contrôle. Par ailleurs le volume courant sous NAVA était corrélé à la capacité pulmonaire totale. Ces études ont montré l’intérêt du monitorage l’EAdi dans le sevrage
The control of breathing results from a complex interaction involving differentrespiratory centers, which feed signals to a central control mechanism that, in turn, provides outputto the effector muscles. Afferent inputs arising from chemo- and mechanoreceptors, related to thephysical status of the respiratory system and to the activation of the respiratory muscles, modulatepermanently the respiratory command to adapt ventilation to the needs. Diaphragm electricalactivation provides information about respiratory drive, respiratory muscle loading, patientventilatorsynchrony and efficiency of breathing in critically ill patients. The use of inappropriatelevel of assist during spontaneous breathing with over or under assist might be harmful withdiaphragmatic dysfunction, alveolar injury and asynchrony. The first study settled NAVA modeaccording to the EAdi recorded during a failed spontaneous breathing trial (SBT). An unexpecteddaily increase of EAdi has been found during SBT until extubation. The second study did not findany increase of the neuroventilatory efficiency during weaning, possibly because of residualsedation. A third study described the inhibition of residual sedation on EAdi and tidal volume at thebeginning of the weaning, and the correlation between them. The last study did not find anyincrease of tidal volume under NAVA after lung transplantation, with denervated lung withoutHerring Breuer reflex, compared to a control group. Moreover tidal volume under NAVA wascorrelated to total lung capacity. These studies highlight the interest of EAdi monitoring duringweaning

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Amorim, Raquel Margarida da Cruz. "O Desmame Precoce da Pessoa submetida a Ventilação Mecânica Invasiva: O Impacto das Intervenções de Enfermagem de Reabilitação". Master's thesis, Instituto Politécnico de Setúbal. Escola Superior de Saúde, 2019. http://hdl.handle.net/10400.26/29374.

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Mestrado em Enfermagem, Área de especialização: Enfermagem de Reabilitação
A Ventilação Mecânica Invasiva é reconhecida como processo terapêutico adjuvante à pessoa acometida de insuficiência respiratória. Em correlação com os seus benefícios, existe a probabilidade de ocorrência de complicações a nível respiratório e motor. Neste contexto, é realçada a importância de realizar um desmame ventilatório precoce. A eficácia e eficiência do desmame ventilatório, requerem do Enfermeiro Especialista em Enfermagem de Reabilitação as competências para elaborar, desenvolver e implementar um plano de intervenção individual, baseado numa avaliação criteriosa do doente. Este relatório surge no decurso da análise ao processo de aquisição e sedimentação de competências comuns do Enfermeiro Especialista, específicas em Enfermagem de Reabilitação, bem como a obtenção de competências de mestre. Este processo foi realizado através das várias fases do plano de intervenção aplicado ao doente submetido a Ventilação Mecânica Invasiva, com o objetivo de desenvolver competências científicas, técnicas e humanas especializadas, ao longo do processo de desmame ventilatório.
Mechanical Invasive Ventilation is recognized as an adjuvant therapeutic process for the person suffering from respiratory failure. In correlation with its benefits, there is a probability of respiratory and motor complications. In this context, the importance of early weaning is emphasized. The efficacy and efficiency of ventilatory weaning require the Nurse Specialist in Rehabilitation Nursing the skills to design, develop and implement an individual intervention plan, based on a careful evaluation of the patient. This report arises during the analysis of the process of acquisition and solidification of common competences of the Specialist Nurse, specific in Rehabilitation Nursing, as well as the acquisition of master's competences. This process was carried out through the various phases of the intervention plan applied to the patient submitted to Mechanical Invasive Ventilation, with the objective of developing specialized scientific, technical and human skills throughout the ventilatory weaning process.

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Craven, Thomas Henry John. "Resolving uncertainty in acute respiratory illness using optical molecular imaging". Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/29507.

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Ventilator associated pneumonia (VAP) and acute respiratory distress syndrome (ARDS) are two respiratory conditions unique to mechanically ventilated patients. The diagnosis of these conditions, and therefore any subsequent treatment, are befuddled by uncertainty. VAP rates vary considerably according to the diagnostic or surveillance criteria used. The pathogenesis of ARDS is well understood but when the internationally agreed consensus criteria are employed, the histological hallmarks are absent about half the time, indicating a disconnection between the clinical diagnosis and what is known about the biology of this condition. It is argued that tests of biological function should be considered in addition to clinical characteristics in order to improve the utility of diagnosis. Given that the pathological sequelae of both VAP and ARDS are driven by an over exuberant host neutrophil response, the activated neutrophil was selected as a potential biological imaging target. Optical molecular imaging uses visible and near visible wavelengths from the electromagnetic spectrum to derive or visualize information based on the optical properties of the target tissue. Optical wavelengths are safe and cheap to work with, producing much higher resolution images than those relying on x-rays or gamma radiation. The imaging modality can be coupled with exogenously applied chemistry to identify specific biological targets or processes. The hypothesis that optical molecular imaging could be used to detect activated neutrophils in real time in the alveolar region of patients was tested. A bespoke optical molecular imaging agent called Neutrophil Activation Probe (NAP), designed in-house, was used to test the hypothesis. NAP is a dendrimeric compound delivered to the alveolar region of a patient in microdoses (≤100 micrograms), becoming fluorescent only on contact with activated neutrophils, and can be detected by optical endomicroscopy. Both the imaging agent and the endomicroscope are delivered to the distal lung via routine bronchoscopy. The agent was tested extensively in the laboratory to demonstrate function, specificity, and safety. Ex vivo testing took place using human and ovine lungs. A regulated dose escalation Phase I clinical trial of investigational medicinal product (CTIMP) in healthy volunteers, patients with bronchiectasis, and mechanically ventilated patients with a pulmonary infiltrate on chest radiography (NCT01532024) was designed and conducted. The aim of the Phase I study was to demonstrate the safety of the technique and to confirm proof of concept. In order to support the requirement for a technique that interrogates alveolar neutrophils two supplementary clinical studies were performed. Firstly, two VAP surveillance techniques (CDC surveillance and HELICS European VAP surveillance) were compared with clinically diagnosed VAP across consecutive admissions in two large tertiary centres for one year. Secondly, the utility of circulating neutrophils to permit discrimination between acute respiratory illnesses was examined. Blood samples from mechanically ventilated patients with and without ARDS underwent flow cytometric assessment using eight clusters of differentiation and internal markers of activation to determine neutrophil phenotype. All clinical studies received the appropriate regulatory, ethical, and/or Caldicott guardian approval prior to commencement. NAP became fluorescent only in the presence of three processes specific to neutrophil activation: active pinocytosis, progressive alkalinization of the phagolysosome, and the activity of human neutrophil elastase. High optical signal was detected following the application of NAP in the alveolar regions of explanted lungs from patients with cystic fibrosis, known to be rich in activated neutrophils. Using an ex vivo ovine lung ventilation and perfusion model optical signal was demonstrated following segmental lung injury. The safety and specificity of the technique in a small cohort of healthy volunteers and mechanically ventilated patients was demonstrated. The technique was tested on a small cohort of patients with bronchiectasis, which provided the first opportunity to obtain broncho-alveolar lavage samples for laboratory correlation. Fluorescent signal was shown in the lavaged neutrophils, labeling that could only have taken place in the alveolar region. The supportive clinical studies found the concordance between actual VAP events was virtually zero even though the reported VAP rates were similar. Furthermore, the rate at which clinicians initiate antibiotics for VAP was approximately five times higher than either surveillance VAP rate. The study of circulating neutrophils from the blood of healthy volunteers and mechanically ventilated patients with and without ARDS indicated circulating neutrophil activation phenotype was not capable of discriminating between clinically diagnosed ARDS and other acute respiratory illnesses. In summary, an ambitious programme of work was completed to develop and support an optical molecular imaging technique that meets the rigorous requirements for human application and can be applied at the bedside to yield immediate visual results. The spatiotemporal relationship of neutrophil activation in real time both in the laboratory and in volunteers and patients was visualized. The visualization of neutrophil activation at such a resolution has never been achieved before in humans, healthy or unhealthy. The Phase I study was not powered to determine utility but recruitment has begun to a Phase II CTIMP (NCT02804854) to investigate the utility, accuracy, and precision of the imaging technique in a large cohort of mechanically ventilated patients. Ultimately, it is proposed that the technique will facilitate diagnosis, stratify patients for treatment and monitor treatment response using this technique.

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