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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Διάγνωση πνευμονικής υπέρτασης με τη χρήση αναίμακτων παρακλινικών εξετάσεων σε ασθενείς με χρόνια αποφρακτική πνευμονοπάθεια

Χαροκόπος, Νικόλαος 12 May 2010 (has links)
- / -
62

Estudo de desenvolvimento do aparelho respiratório de embriões bovinos (Bos indicus e Bos taurus) durante o período gestacional compreendido entre 10 e 60 dias / Study about the development of respiratory system in bovines embryos (Bos indicus and Bos taurus) during the gestation period 10 - 60 days

Miryan Lança Vilia Alberto 19 December 2006 (has links)
A presente investigação científica visou estudar o desenvolvimento do Aparelho Respiratório de bovinos, durante o período embrionário, através de técnicas empregadas em microscopias de luz transmitida e eletrônica de transmissão. Em nossos resultados pudemos observar a formação do tubo laringotraqueal em embriões apresentando idade gestacional estimada de 20 / 21 dias (CR 9,0 mm), sendo sua parede formada por epitélio constituído de várias camadas de células apoiado em mesênquima. No interior do pulmão, as áreas subjacentes ao epitélio apresentam mesênquima condensado e áreas mais afastadas mesênquima frouxo, sendo que neste último já estão presentes os vasos sanguíneos, contendo células próprias em seu interior. As células mesenquimais apresentaram formas irregulares, com aspecto estrelado ou fusiforme estando unidas por desmossomos, locais onde o citoesqueleto se prende a membrana celular, formando um elo de ligação. A bifurcação da porção caudal da traquéia nos brônquios principais é simultânea ao surgimento do brônquio traqueal, ocorrendo em embriões com idade gestacional de 28 dias (CR 12,0 mm). / The present study aims at investigating the development of the respiratory system in bovines during embryonic phase, using techniques of transmitted light microscopy and electronic transmissions. The results show the development of the laryngotracheal tube in embryos at approximately 20 / 21 days of gestation (CR 9.0 mm), being the walls of the tube made of epithelium with several layers of cells supported by mesenchyme. Inside the lung, the areas next to the epithelium show a condensed mesenchyme and further, there is a loose mesenchyme where blood vessels containing cells of their own kind can be observed. The mesenchymal cell displays irregular shapes, stellate or fusiform, being united by desmosomes, where the cytoskeleton is attached to the cell membrane creating a link. The bifurcation of the tail end of the trachea in the main bronchi is concomitant to the arising of the tracheal bronchus, occurring in embryos at 28 days of gestation (CR 12.0 mm).
63

DiagnÃsticos de enfermagem respiratÃrios em crianÃas com infecÃÃo respiratÃria aguda: um estudo longitudinal / NURSING DIAGNOSIS RESPIRATORY IN CHILDREN WITH ACUTE RESPIRATORY: A LONGITUDINAL STUDY

LÃvia Maia Pascoal 23 December 2011 (has links)
nÃo hà / No Ãmbito da enfermagem, os estudos de acurÃcia contribuem com a melhoria da qualidade da assistÃncia por permitir a identificaÃÃo de caracterÃsticas definidoras com bom poder preditivo e influenciar diretamente na escolha do diagnÃstico de enfermagem adequado a cada situaÃÃo clÃnica. Devido à importÃncia de pesquisas relacionadas a essa temÃtica, este estudo foi realizado com o objetivo de analisar a capacidade preditiva das caracterÃsticas definidoras dos diagnÃsticos de enfermagem âPadrÃo respiratÃrio ineficaz (PRI), DesobstruÃÃo ineficaz das vias aÃreas (DIVA) e Troca de gases prejudicada (TGP)â em crianÃas com infecÃÃo respiratÃria aguda (IRA). Foi desenvolvido um estudo de coorte aberta, nos meses de janeiro a junho de 2011, em dois hospitais infantis da rede pÃblica do municÃpio de Fortaleza-CE. A amostra foi composta por 136 crianÃas as quais foram acompanhadas por um perÃodo mÃnimo de seis e mÃximo de dez dias. Para a coleta de dados, foi utilizado um instrumento baseado nas caracterÃsticas dos diagnÃsticos estudados e na literatura pertinente acerca da avaliaÃÃo pulmonar. Os dados foram coletados atravÃs de exame fÃsico da crianÃa e entrevista com os responsÃveis. As informaÃÃes obtidas foram analisadas pela pesquisadora para determinar a presenÃa ou ausÃncia das caracterÃsticas de PRI, DIVA e TGP e posteriormente foram encaminhados para enfermeiros diagnosticadores que executaram o processo de inferÃncia diagnÃstica. Foram utilizados os softwares Excel e PASW para organizaÃÃo e anÃlise estatÃstica dos dados. O nÃvel de significÃncia adotado foi de 5%. A anÃlise da evoluÃÃo temporal dos diagnÃsticos DIVA, TGP e PRI mostrou uma tendÃncia curvilÃnea, com reduÃÃo ao longo do perÃodo de acompanhamento. Para DIVA e PRI, verificou-se uma distribuiÃÃo semelhante apesar de terem ocorrido em proporÃÃes diferentes, mas DIVA manteve altos valores nos dez dias de seguimento. Quanto Ãs medidas de acurÃcia, as caracterÃsticas mais acuradas para predizer a ocorrÃncia de DIVA, TGP e PRI foram RuÃdos adventÃcios respiratÃrios, Hipoxemia e Uso de musculatura acessÃria para respirar, respectivamente. Todas as crianÃas avaliadas desenvolveram DIVA atà o final do tempo de acompanhamento e nenhuma relaÃÃo estatisticamente significante foi encontrada entre o tempo de sobrevida e as variÃveis analisadas. Do total de crianÃas acompanhadas, 86,76% desenvolveram TGP durante o perÃodo de acompanhamento. O tempo de internamento foi a Ãnica variÃvel que apresentou correlaÃÃo estatisticamente significante com o tempo de sobrevida. A mediana do tempo de sobrevida para PRI foi de um dia e do total de crianÃas acompanhadas, 86,76% desenvolveram este diagnÃstico durante o perÃodo de seguimento. Com base na anÃlise de correspondÃncias mÃltiplas, as caracterÃsticas que melhor auxiliam na diferenciaÃÃo entre os diagnÃsticos estudados sÃo: ExpectoraÃÃo, Tosse ausente, VocalizaÃÃo dificultada e RuÃdos respiratÃrios adventÃcios para DIVA; AgitaÃÃo e Irritabilidade para TGP e AlteraÃÃo na profundidade respiratÃria, Uso de musculatura acessÃria para respirar e RespiraÃÃo anormal para PRI. Estudos desta natureza sÃo importantes por fornecer informaÃÃes sobre a capacidade preditiva das caracterÃsticas definidoras bem como a evoluÃÃo temporal e as particularidades dos diagnÃsticos de enfermagem respiratÃrios em crianÃas com infecÃÃo respiratÃria aguda. / Through nursing subject, studies of accuracy contribute to improve the quality of care by allowing the identification of defining characteristics (DC) with good predictive power and directly influence the choice of nursing diagnosis appropriate to each clinical situation. Because the importance of research related to this subject, this study was made with the goal to analyze the predictive ability of the DC of nursing diagnoses Ineffective Breathing Pattern (IBP), Ineffective airway clearance (IAC) and Impaired gas exchange (IGE) in children with acute respiratory infection (ARI). It was developed an open cohort study in the months January to June 2011, two children hospitals in the public network in Fortaleza-CE. The sample was consisted of 136 children, who were followed for a minimum period of six and maximum of ten days. To collect the data, it was used an instrument based on the characteristics of the diagnostics studied and some relevant literature about the lung evaluation. The data were collected through examination of the child and interview with their responsibles. The information obtained was analyzed by the researcher to determine the presence or ausence of the characteristics of IBP, IAC and IGE and lately were sent to nurses diagnosticians that performed the diagnostic inference process. It was used Excel and PASW software for organizing and analyzing statistical data. The level of significance was 5%. The temporal evolution of the diagnostics IAC, IBP and IGE showed a curvilinear trend, with reduction over the monitoring period. For IAC and IBP, there was a similar distribution although they occurred in different proportions, but IAC maintained high values in ten days of follow-up. The measures of accuracy, the characteristics more accurated for predicting the occurrence of IAC, IGE and IBP were respiratory rales, hypoxemia and use of accessory muscles to breathe, respectively. All children evaluated IAC developed by the end of follow-up time and no statistically significant relationship was found between survival time and the variables analyzed. Of the total number of children followed, 86.76% developed IGE during the follow-up period. The time of hospital staying was the only variable that showed a correlation statistically significant with survival time. The median survival time for IBP was a day of total and accompanied children, 86.76% developed this diagnosis during the study period. Based on the analysis of multiple matches, the best characteristics that assist in differentiating between the diagnoses studied are: expectoration, cough absent, Speech and difficult to IAC adventitious breath sounds, agitation and irritability for IGE and Change in the depth of breathing, use of accessory muscles breathing and anormal breathing for IBP. Studies of this nature are important for providing information about the predictive ability of the defining characteristics and the temporal evolution and characteristics of the respiratory nursing diagnoses in children with acute respiratory infection.
64

Infecção grave do trato respiratório inferior em crianças menores de 3 anos : etiologia viral e co-detecção como fatores de risco / Severe lower respiratory tract infection in infants and toddlers : viral etiology and co-detection as risk factors

Silva, Emerson Rodrigues da, 1972- 24 August 2018 (has links)
Orientadores: José Dirceu Ribeiro, Renato Tetelbom Stein / Tese (doutorado) ¿ Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T01:47:34Z (GMT). No. of bitstreams: 1 Silva_EmersonRodriguesda_D.pdf: 2935794 bytes, checksum: a3a21e8b226c670f1ac8d027e5ed10a1 (MD5) Previous issue date: 2013 / Resumo: Introdução: A infecção do trato respiratório inferior (ITRI) é uma das principais causas de morbimortalidade em crianças, principalmente em países em desenvolvimento e em crianças menores de 3 anos de idade. Os vírus estão entre os principais agentes etiológicos das ITRI em crianças. No entanto, poucos estudos até o momento investigaram o impacto dos vírus respiratórios em populações de crianças de países em desenvolvimento e de que maneira as codetecções de dois ou mais vírus modificam a gravidade das infecções. Objetivo: identificar quais vírus respiratórios causam ITRI em lactentes e crianças até 3 anos de idade hospitalizadas e qual o impacto das codetecções virais sobre a gravidade destes episódios. Métodos: crianças de até 3 anos de idade internados em um hospital terciário no Brasil durante os meses de alta prevalência de vírus respiratórios tiveram amostras coletadas de aspiração nasofaríngea. Estas amostras foram testadas para 13 diferentes vírus respiratórios através de PCR em tempo real (RT-PCR). Os pacientes foram acompanhados durante a internação, e dados clínicos e das características da população foram registradas durante esse período e na alta para avaliar marcadores de gravidade, como tempo de internação e uso de oxigênio. Foi usada análise univariada para identificar potenciais fatores de risco e a regressão logística multivariada para determinar o impacto de detecções virais específicas sobre os desfechos, bem como para avaliar o efeito das codetecções sobre estes mesmos desfechos. Resultados: Foram analisados 260 episódios de ITRI com uma taxa de detecção viral de 85% (n = 222). Codetecção foi observada em 65% de todos os episódios de vírus-positivos. O vírus foi mais prevalente Vírus Sincicial Respiratório (RSV) (54%), seguido por Metapneumovirus humano (hMPV) (32%) e Rinovírus humano (HRV) (21%). Nos modelos multivariados, lactentes com codetecção de HRV + RSV permaneceram 4,5 dias a mais no hospital (p = 0,004), quando comparados ao grupo sem a codetecção. A mesma tendência foi observada para o número de dias de uso de oxigênio suplementar. Conclusões: Embora RSV permaneça como a principal causa da ITRI em crianças, mostrou-se um aumento no tempo de internação e uso de oxigênio em crianças com RSV e HRV codetectados por RT-PCR em comparação com aqueles com RSV mas sem HRV em codetecção. Além disso, nosso estudo identificou um número significativo de crianças infectadas por vírus recentemente identificados, tais como hMPV e bocavirus Humano (HBoV), e este é um achado relevante para comunidades pobres de países em desenvolvimento / Abstract: Introduction: lower respiratory tract infection (LRTI) is a major cause of morbidity and mortality in infants and children, especially in developing countries and in children under 3 years old. Viruses are among the major etiologic agents of LRTI in children. However, few studies to date have investigated the impact of respiratory viruses in populations of children in developing countries and how the co-detections of two or more viruses modify the severity of infections. Objective: To identify respiratory viruses in infants and children up to 3 years of age hospitalized due to LRTI and verify the impact of viral co-detections on the severity of these episodes. Methods: Children less than 3 years of age admitted to a tertiary hospital in Brazil during the months of high prevalence of respiratory viruses had collected samples of nasopharyngeal aspirate. These samples were tested for 13 different respiratory viruses by real-time PCR (RT-PCR). Patients were followed during hospitalization, and clinical and population characteristics were recorded during this period and at discharge to assess markers of severity, such as length of stay and use of oxygen. Univariate analysis was used to identify potential risk factors and multivariate logistic regression was used to determine the impact of specific viral detections on outcomes and to evaluate the effect of co-detections on these same outcomes. ix Results: We analyzed 260 episodes of LRTI with an overall viral detection rate of 85% (n = 222). Co-detection was observed in 65% of all virus-positive episodes. The most prevalent virus was Respiratory Syncytial Virus (RSV) (54%), followed by human metapneumovirus (hMPV) (32%) and human rhinovirus (HRV) (21%). In multivariate models, infants with co-detection of HRV + RSV stayed 4.5 days longer in the hospital (p = 0.004), when compared to the group without this co-detection. The same trend was observed for the number of days using supplemental oxygen. Conclusions: Although RSV remains the leading cause of LRTI in children, our study has shown an increase in the length of stay and use of oxygen in children with RSV and HRV co-detected by RT-PCR in comparison with those with RSV alone. Furthermore, our study identified a significant number of children infected by viruses recently identified, such as hMPV and Human bocavirus (HBoV), and this is an important finding for poor communities in developing countries / Doutorado / Pediatria / Doutor em Saude da Criança e do Adolescente
65

The effect of low-dust forages and the role of pro-resolving lipid mediators in mild-moderate equine asthma

Carla Olave (9027407) 25 June 2020 (has links)
<p>Mild-moderate equine asthma (EA) is a commonly encountered disease of racehorses that affects performance. Decreasing dust exposure is crucial in the treatment of equine asthma. Dry hay, because of its high dust content, is known to increase the risk of airway inflammation. Feeding haylage, steamed hay, or hay pellets instead can help to decrease dust exposure. Haylage may also contribute to the resolution of airway inflammation by providing higher levels of omega-3 polyunsaturated fatty acids (Ω-3). Higher levels of Ω-3 are associated with an increase in pro-resolving lipid mediators (PRLM), essential molecules in the resolution of airway inflammation. </p> <p> The studies presented in this dissertation were designed to test the hypothesis that feeding low-dust forages would decrease airway inflammation in racehorses, and that haylage would provide superior resolution of airway inflammation compared to other low dust forages due to changes in systemic Ω-3 and PRLM concentrations associated with increased dietary Ω-3 intake.</p> <p>Three clinical trials were conducted to determine the effect of low-dust forages on airway inflammation. Environmental exposures were measured at the breathing zone, and bronchoalveolar lavage (BAL), and differential cytology counts were performed as measure of airway inflammation. </p> <p>The first clinical trial was a pilot study performed with 7 Standardbred racehorses. Horses were randomly assigned to eat hay (n=3) or haylage (n=4) for 6 weeks while in training. Measurements were performed at baseline and after 2, 4, and 6 weeks. Results showed a decrease in respirable dust, and β-glucan exposure in the horses fed haylage when compared to those fed hay. BAL neutrophil proportion was significantly lower at weeks 2, 4, and 6 when compared to baseline and at week 6 when compared to horses fed hay. </p> <p> The second clinical trial was performed on 19 mild asthmatic horses from the teaching herd. The diet of these horses was changed from dry hay to haylage (n=9) or hay pellets (n=10) for 6 weeks. Measurements were performed at baseline, week 3, and week 6. Results indicated that horses eating haylage and hay pellets were exposed to similar dust levels that were significantly lower than when they were eating dry hay. BAL neutrophil proportion was significantly lower in horses eating haylage when compared to baseline and to horses eating hay pellets at week 6. Horses eating haylage exhibited a significant decrease in stearic acid concentration at week 6. Pro-resolving lipid mediators (Resolvin D1, Resolvin E1, and Lipoxin A<sub>4</sub>) did not affect neutrophil apoptosis or efferocytosis <i>in vitro</i>.</p> <p>The third clinical trial was performed on 73 thoroughbred racehorses actively racing and training. Horses were randomly assigned to eat dry hay or to change the forage to steamed hay or haylage. No other change in the management of the horses was allowed. Measurements were performed at baseline (n=73), week 3 (n=69), and week 6 (n=53). Results indicated that respirable dust exposure was significantly reduced when racehorses were fed steamed hay or haylage in place of dry hay. Respirable dust exposure was positively associated with BAL neutrophil proportions. Feeding haylage also significantly decreased exposure to respirable endotoxins. Horses eating haylage for 3 weeks had significantly lower BALF neutrophil proportion when compared with baseline. Also, at week 3, horses eating haylage showed a significant decrease in mast cell proportion, and horses eating steamed hay had a significant decrease in eosinophil proportion. At week 6, horses eating haylage maintained significantly lower BALF neutrophil proportions compared to baseline, and horses eating hay for 6 weeks. Concentration of Ω-3 and PRLM were not increased in horses eating haylage when compared to horses fed hay. Eicosapentaenoic acid was significantly higher on the horses eating haylage when compared to horses eating steamed hay. </p> <p>In conclusion, feeding low-dust forages is sufficient to decrease breathing zone exposure of horses to respirable dust. Despite similar dust exposure, haylage was the only low-dust forage that resulted in resolution of neutrophilic airway inflammation; however, the mechanism remains unclear.</p>
66

ECMO Support for Pediatric Burn Patients: A Potential Life Saving Modality

Dawoud, Fakhry, Thompson, Brian, Castle, Shannon 12 April 2019 (has links)
Extracorporeal membrane oxygenation (ECMO) has been used as life-saving support for children with varying causes of respiratory and/or cardiac failure. However, few studies have assessed the utility of ECMO as a viable treatment option in the setting of pediatric burn injury. We aim to examine the outcomes of pediatric burn patients requiring ECMO support by utilizing the Extracorporeal Life Support Organization (ELSO) registry in order to elucidate whether or not ECMO should be considered in this population. A retrospective cohort study was conducted by querying the ELSO database for all pediatric patients (birth to less than 18 years) who were supported on ECMO with burn-associated cardiopulmonary failure between 1990 and 2016. ICD-9 codes 940–949.5 were utilized to identify patients with an associated burn injury. Venovenous ECMO was defined as any patient with only venous cannulas, including double-lumen venous cannulas. Venoarterial ECMO was defined as any patient with a venous and an arterial cannula, any patient originally supported on VA ECMO that was converted to venovenous, or any patient originally supported on venovenous that was converted to venoarterial ECMO. Oxygenation indices (OI) and complication rates were compared among survivors and non-survivors for both venovenous (VV) and venoarterial (VA) groups. Primary outcome variables were survival and non-survival to hospital discharge. Demographic and clinical data, along with pre-ECMO variables and ECMO complications, were analyzed for predictive mortality. A total of 113 patients met inclusion criteria for the study. Overall survival to discharge was 52.2% (n=59) for the entire cohort. 73 patients were supported on VA ECMO, while 37 patients required VV ECMO support with a survival to discharge of 47.9% (n=35) and 62.2% (n=23), respectively. There was no statistical difference for median age (p=0.765), median weight (p=0.932), or median hours on ECMO (p=0.963) between survivors and non-survivors. Three patients did not have the type of cannulation identified but were listed as “other” in the ELSO registry. Patients requiring ECMO support for respiratory failure had a higher over-all survival (55.7%, n=97) compared to those requiring ECMO for cardiac failure (33.3%, n=6) or ECPR (30%, n=10). Patients who were supported on VV ECMO for respiratory failure had the best overall survival at 62.2% (n=37) and those cannulated to VA ECMO for respiratory failure had a survival of 51.7% (n=58). Patients supported on VA ECMO for cardiac failure or ECPR support had the same survival at 33.3% (n=6 and 9 respectively). Several factors were found to be significantly associated with mortality. Cardiac arrest prior to cannulation was associated with increased mortality with an odds ratio of 3.41 (95% CI 1.29-9.06, p=0.011). There was a trend for the use of nitric oxide prior to cannulation to be associated with a decrease in mortality with an odds ratio of 0.40 (95% CI 0.16-1.01, p=0.048)Following cannulation, complications including the need for inotropes (OR 2.64, 95% CI 1.24-5.65, p=0.011), presence of gastrointestinal hemorrhage (p=0.049), and hyperglycemia (glucose > 240mg/dL) (OR 3.42, 95% CI 1.13-10.38, p=0.024) were associated with increased mortality.
67

Diagnostic exposure of ionizing radiation and its long-term effects

McEvoy, James Hugh January 2020 (has links)
Medical radiation is vital in acquiring a patient diagnosis, but some clinicians are concerned with the perceived risks associated with ionizing radiation. This risk is heightened when incorporating in utero exposures due to the risk to the developing foetus. Although other organ systems have been studied, there is a paucity of data on the effects to the respiratory system from in utero exposures. The aim of this thesis was to understand the long-term effects on the respiratory system from in utero exposures, but as a first step, it was important to determine what levels patients receive whilst admitted to hospital. Two polar populations were chosen based on their predicted exposure levels during hospitalisation; one with high levels, intensive care unit (ICU) patients, and one with low levels, pregnant patients. Most patients cumulatively received < 1mSv with median exposures of 0.99 mSv (ICU patients) and 0.02 mSv (pregnant patients). However, both cohorts had patients that surpassed 10 mSv. To assess the effects from in utero exposures on the respiratory system, two animal models were conducted both exposed during late gestation, one healthy model and one acute lung injury model. In the health animal model, cardiovascular outcomes were also measured, however, ionizing radiation (50, 300, 1000 mGy) did not appear to influence these two organ systems from the outcomes measured. In the acute lung injury model, lipopolysaccharide (3mg/Kg) stimulated an acute lung inflammatory response, however, there was also no overt effect of radiation from the outcomes measured (10, 100, 1000 mGy). In both models, ionizing radiation did cause growth restriction up to 16 weeks of age, but this was only observed from doses above 100 mGy. Overall, the levels of ionizing radiation patients receive is low and from diagnostic exposures during pregnancy, there does not appear to be any strong effects on the developing foetus. / Thesis / Doctor of Philosophy (PhD) / Radiation is necessary in medicine to observe the internal structures of the body, but it can sometimes cause unwanted biological changes within the body. This risk is heightened when considering exposure to developing baby because of the dynamic changing it is naturally going through and possible lifetime left to experience effects. This thesis aimed to understand what levels of radiation patients receive in hospital, observing one population predicted to receive high levels (Intensive care patients) and one predicted to receive low levels (pregnant patients). Overall, the majority of patients in the two cohorts received less than the recommended yearly public limit of 1 millisievert (mSv). The second aim was to observe the effects on the growth, lungs and hearts of the babies in an animal model when they are exposed during pregnancy. Radiation had no overall effect on the lungs or heart but can reduce body weight at moderate (100 milligrays (mGy) and high (1000 mGy) exposures.
68

Artificial Neural Networks (ANN) in the Assessment of Respiratory Mechanics

Perchiazzi, Gaetano January 2004 (has links)
<p>The aim of this thesis was to test the capability of Artificial Neural Networks (ANN) to estimate respiratory mechanics during mechanical ventilation (MV). ANNs are universal function approximators and can extract information from complex signals. </p><p>We evaluated, in an animal model of acute lung injury, whether ANN can assess respiratory system resistance (R<sub>RS</sub>) and compliance (C<sub>RS</sub>) using the tracings of pressure at airways opening (P<sub>AW</sub>), inspiratory flow (V’) and tidal volume, during an end-inspiratory hold maneuver (EIHM). We concluded that ANN can estimate C<sub>RS</sub> and R<sub>RS</sub> during an EIHM. We also concluded that the use of tracings obtained by non-biological models in the learning process has the potential of substituting biological recordings.</p><p>We investigated whether ANN can extract C<sub>RS</sub> using tracings of P<sub>AW</sub> and V’, without any intervention of an inspiratory hold maneuver during continuous MV. We concluded that C<sub>RS</sub> can be estimated by ANN during volume control MV, without the need to stop inspiratory flow.</p><p>We tested whether ANN, fed by inspiratory P<sub>AW </sub>and V’, are able to measure static total positive end-expiratory pressure (PEEP<sub>tot,stat</sub>) during ongoing MV. In an animal model we generated dynamic pulmonary hyperinflation by shortening expiratory time. Different levels of external PEEP (PEEP<sub>APP</sub>) were applied. Results showed that ANN can estimate PEEP<sub>tot,stat</sub> reliably, without any influence from the level of PEEP<sub>APP</sub>.</p><p>We finally compared the robustness of ANN and multi-linear fitting (MLF) methods in extracting C<sub>RS</sub> when facing signals corrupted by perturbations. We observed that during the application of random noise, ANN and MLF maintain a stable performance, although in these conditions MLF may show better results. ANN have more stable performance and yield a more robust estimation of C<sub>RS</sub> than MLF in conditions of transient sensor disconnection.</p><p>We consider ANN to be an interesting technique for the assessment of respiratory mechanics.</p>
69

Artificial Neural Networks (ANN) in the Assessment of Respiratory Mechanics

Perchiazzi, Gaetano January 2004 (has links)
The aim of this thesis was to test the capability of Artificial Neural Networks (ANN) to estimate respiratory mechanics during mechanical ventilation (MV). ANNs are universal function approximators and can extract information from complex signals. We evaluated, in an animal model of acute lung injury, whether ANN can assess respiratory system resistance (RRS) and compliance (CRS) using the tracings of pressure at airways opening (PAW), inspiratory flow (V’) and tidal volume, during an end-inspiratory hold maneuver (EIHM). We concluded that ANN can estimate CRS and RRS during an EIHM. We also concluded that the use of tracings obtained by non-biological models in the learning process has the potential of substituting biological recordings. We investigated whether ANN can extract CRS using tracings of PAW and V’, without any intervention of an inspiratory hold maneuver during continuous MV. We concluded that CRS can be estimated by ANN during volume control MV, without the need to stop inspiratory flow. We tested whether ANN, fed by inspiratory PAW and V’, are able to measure static total positive end-expiratory pressure (PEEPtot,stat) during ongoing MV. In an animal model we generated dynamic pulmonary hyperinflation by shortening expiratory time. Different levels of external PEEP (PEEPAPP) were applied. Results showed that ANN can estimate PEEPtot,stat reliably, without any influence from the level of PEEPAPP. We finally compared the robustness of ANN and multi-linear fitting (MLF) methods in extracting CRS when facing signals corrupted by perturbations. We observed that during the application of random noise, ANN and MLF maintain a stable performance, although in these conditions MLF may show better results. ANN have more stable performance and yield a more robust estimation of CRS than MLF in conditions of transient sensor disconnection. We consider ANN to be an interesting technique for the assessment of respiratory mechanics.
70

Desempenho respiratório na transição feto-neonatal de cães nascidos em eutocia vaginal ou cesariana eletiva / Respiratory performance in dogs born by vaginal eutocia or elective cesarean section in the transition from fetal to neonatal life

Abreu, Renata Azevedo de 23 November 2018 (has links)
O sucesso da adaptação imediata para a vida extrauterina depende da apropriada função pulmonar. Em neonatologia humana, é estabelecido que a cesariana eletiva aumenta o risco de angústia respiratória, como resultado da reduzida remoção do fluido pulmonar. Neste contexto, este estudo objetivou avaliar a influência da condição obstétrica no desempenho respiratório dos recém-nascidos caninos no período de transição, em especial os fatores que determinam a remoção do fluido pulmonar. Para tal, foram selecionadas 20 fêmeas caninas e 37 neonatos, os quais constituíram dois grupos, de acordo com a condição obstétrica: Eutocia Vaginal (n=10 parturientes; n= 17 neonatos) e Cesariana Eletiva (n= 10 parturientes; n= 20 neonatos). A avaliação materna consistiu na dosagem sérica de cortisol e catecolaminas (adrenalina e noradrenalina) em momentos pontuais no pré, intra e pós-parto. Os neonatos foram avaliados por meio do escore de vitalidade neonatal, bem como avaliação das frequências cardíaca e respiratória, aferição da temperatura corpórea e peso corporal, avaliação hemogasométrica venosa, dosagem sérica de cortisol e catecolaminas, lactatemia, glicemia, oximetria de pulso e avaliação radiográfica pulmonar em momentos pontuais no decorrer das primeiras 24 horas de vida. Adicionalmente, foi avaliado a composição eletrolítica e a concentração de cortisol no líquido amniótico de cada filhote. O parto vaginal determinou menor estresse materno, porém, maior concentração de cortisol no líquido amniótico e soro sanguíneo dos filhotes, contribuindo para melhor adaptação cardiorrespiratória e metabólica. Por outro lado, a cesariana eletiva resultou em maior estresse materno, contrariamente ao perfil hormonal dos filhotes e retardou a remoção do fluido pulmonar, resultando em hipoxemia mais severa, além de dificultar a resposta compensatória ao desequilíbrio ácido-básico sanguíneo e termorregulação. Em conclusão, a condição obstétrica impõe diferenças na adaptação pulmonar, interferindo no desempenho respiratório de cães no período de transição feto-neonatal. / The success of immediate adaptation to extrauterine life depends on appropriate lung function. In human neonatology, it is established that elective cesarean section increases the risk of respiratory distress as a result of reduced pulmonary fluid reabsortion. In this context, this study aimed to evaluate the influence of the obstetric condition on the respiratory performance of canine neonates in the transition period, specially the factors that determine the removal of the pulmonary fluid. For this purpose, 20 canine females and 37 neonates were selected, according to the obstetric condition: Vaginal Eutocia (n = 10 bitches, n = 17 neonates) and Elective Cesarian Section (n = 10 bitches, n = 20 neonates). Maternal evaluations were performed to evaluate serum cortisol and catecholamines (adrenaline and noradrenaline) levels at punctual moments in pre, intra and postpartum. Neonates were evaluated for the neonatal vitality score, as well as evaluation of heart and respiratory rates, body temperature and body weight, venous hemogasometric evaluation, serum cortisol and catecholamines, blood lactate, blood glucose, pulse oximetry and radiographic evaluation during the first 24 hours of life. Additionally, the electrolyte composition and cortisol concentration in the amniotic fluid of each puppy was evaluated. The vaginal delivery determined lower maternal stress, however, a higher cortisol concentration in the amniotic fluid and neonatal blood serum, contributing to a better cardiorespiratory and metabolic adaptation. On the other hand, elective cesarean section resulted in higher maternal stress contrary to the neonatal hormonal profile and delayed the removal of the pulmonary fluid, resulting in more severe hypoxemia, besides a less efficient compensatory response to acid-base imbalance and thermoregulation. In conclusion, the obstetric condition imposes differences in pulmonary adaptation, interfering in the respiratory performance of dogs in the transition from fetal to neonatal life.

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