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Sedação em endoscopia digestiva alta: estudo comparativo com uso combinado de propofol e fentanil versus midazolam e fentanil / Randomized controlled trial comparing propofol and fentanyl versus midazolam and fentanyl for sedation in upper gastrointestinal endoscopyMarcos Eduardo Lera dos Santos 18 November 2011 (has links)
Introdução: o uso da sedação na rotina endoscópica tem sido empregado praticamente de maneira universal. O emprego de propofol parece se relacionar a exame mais confortável, com aumento da satisfação com o exame, pelo médico e pelo paciente. Entretanto, o uso do propofol está associado ao maior risco de sedação profunda e às complicações a ela associadas. Objetivo: comparar dois esquemas de sedação para a realização de endoscopia digestiva alta diagnóstica, grupo midazolam (midazolam e fentanil) com o grupo propofol (propofol e fentanil) quanto ao nível de sedação profunda e, como desfechos secundários, o grau de satisfação, o tempo de recuperação e a frequência de complicações entre os grupos. Método: foi realizado estudo experimental, prospectivo, randômico, cego com 200 pacientes, 100 no grupo midazolam e 100 no grupo propofol. Resultado: utilizando a escala OAA/S e o índice bispectral (BIS), respectivamente 11% e 7% dos pacientes do grupo midazolam e 25% e 19 % do grupo propofol apresentaram níveis de sedação profunda, sendo significativamente mais frequente neste último grupo. Houve boa correlação do nível de sedação da escala clínica OAA/S com o índice bispectral (BIS) para os dois grupos (k=0,63 para o grupo midazolam e k=0,71 para o grupo propofol). Quarenta e dois por cento dos pacientes do grupo propofol e 26% dos pacientes do grupo midazolam precisaram de oferta suplementar de oxigênio (p=0,025). O tempo médio de recuperação dos pacientes do grupo midazolam foi de 44,13 min e do grupo propofol foi de 28,82 min (p<0,001). O grau de satisfação dos pacientes foi semelhante entre os grupos e os médicos deram preferência ao uso da associação propofol/fentanil. Não se observaram complicações graves decorrentes da sedação em ambos os grupos. Conclusão: ambos os esquemas de sedação levam à sedação profunda. O grupo propofol utilizando o propofol e fentanil apresentou eventos de sedação profunda mais frequentemente. Por outro lado, os dois esquemas são seguros. Os pacientes do grupo propofol apresentaram tempo de indução da sedação, de recuperação e de liberação menores / Introduction: the use of sedation is almost universal for the practice of upper gastrointestinal (GI) endoscopy. The use of propofol seems to be associated with higher physician and patient satisfaction. However there is a higher risk of deep sedation and its related complication when propofol is used. Objective: compare the frequency of deep sedation events with two drug associations for the sedation in upper GI endoscopy. The OAA/S score and the bispectral index monitoring (BIS) were employed for the assessment of consciousness level. Secondarily we compared patient and physician satisfaction, recovery time and the complication rates between the two groups. Methods: two hundred patients sent for upper GI endoscopy were randomized in two groups: midazolam and propofol, each of them with 100 patients. Results: Deep sedation events occurred in 11% (OAA/S score) and 7% (BIS) in group midazolam and significantly more frequent in group propofol (25%- OAA/S score and 19% - BIS). There was a good agreement between the OAA/S score and the bispectral index (BIS) in both groups (k=0.63 and K=0.71 for groups midazolam and propofol, respectively). Forty two per cent of group propofol patients and 26% of group midazolam patients needed oxygen supplementation (p=0.025). The mean recovery time for groups midazolam and propofol patients were 44.13 min and 28.82 min, respectively (p<0.001). While patients were equally satisfied with both drug associations, physicians were more satisfied with the propofol/fentanyl association. We did not record any severe complications related with sedation. Conclusion: both drug associations are associated with deep sedation events. The propofol/fentanyl association causes deep sedation events more frequently when compared with midazolam/fentanyl association. Both associations are safe. The induction sedation, recovery and discharge times were shorter with propofol/fentanyl association
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Endoscopia de contato (microestomatoscopia) nas lesões da boca e do lábio: avaliação do método / Contact endoscopy in oral lesions: method assessmentGyl Henrique Albrecht Ramos 15 October 2008 (has links)
INTRODUÇÃO: a expectativa de incidência do câncer da cavidade oral estimada para 2008, no Brasil, é de 14.160 casos e cerca de 50% desses tumores serão diagnosticados tardiamente. Os procedimentos diagnósticos menos invasivos e confiáveis podem incrementar o diagnóstico precoce. OBJETIVOS: a) descrever as dificuldades da endoscopia de contato aplicada à boca e ao lábio (microestomatoscopia de contato); b) aplicar no diagnóstico das lesões do lábio os critérios usados na endoscopia de contato de outras topografias; c) descrever parâmetro objetivo para a aplicação do critério Celularidade; d) comparar os diagnósticos deste exame, nas lesões do vermelhão do lábio inferior, com os do anatomopatológico. MÉTODO: o estudo foi prospectivo, de casos não consecutivos, utilizando o endoscópio de contato Storz 8715 A e o corante azul de toluidina. Foi dividido em Estudo Inicial, com 31 exames (21 do lábio e 10 da boca) para objetivos a e b, e em Estudo Final, com 69 exames (53 do vermelhão e 16 da mucosa labial sem lesão) para objetivos c e d. No primeiro, interessaram lesões do lábio e da boca, apenas exames in vivo e sem biópsia dirigida. No segundo, interessaram lesões do vermelhão do lábio inferior, apenas exames ex vivo e com biópsia dirigida. Os critérios aplicados foram Celularidade, Arquitetura, Extratificação e Morfometria. O critério Celularidade foi dividido em faixas conforme a contagem manual das células de cada lesão benigna e maligna. Foram aplicados análises de regressão e o teste de correlação de Kendall. RESULTADOS: a falta de nitidez das imagens ocorreu em 100% dos casos, os critérios, quando alterados em conjunto, definiram malignidade à microestomatoscopia de contato. Estudo Final: o teste de Kendall foi significativo para todos os critérios; O critério Celularidade foi dividido em quatro faixas (Risco Mínimo (RM), Pouco Risco (PR), Médio Risco (MR) e Alto Risco (AR). A análise de regressão destacou que os critérios Estratificação e Celularidade, assim como as faixas Risco Mínimo (RM) e Pouco Risco (PR), juntas, foram significativos para o diagnóstico de malignidade. Não ocorreram falsonegativos e os falso-positivos foram 9,4%. A sensibilidade para o diagnóstico de malignidade foi 100%, a especificidade 88%, o valor preditivo positivo 70,5%, o valor preditivo negativo 100% e a acurácia 90,3%. CONCLUSÃO: as dificuldades encontradas (contato do aparelho com a superfície anatômica, deslizamento do aparelho, tremores finos e falta de nitidez da imagem) não inviabilizaram o procedimento. Os critérios puderam ser observados e estavam correlacionados entre si. As faixas RM e PR agrupadas confirmaram a significância da divisão por faixas. A sensibilidade e a especificidade foram altas e com bom valor preditivo positivo para o diagnóstico de lesões malignas do vermelhão do lábio inferior. O estudo sugere que a microestomatoscopia de contato é útil no diagnóstico das lesões do lábio, da boca, especialmente do vermelhão do lábio inferior / INTRODUCTION: In Brazil, the expectation of incidence of oral cavity cancer is estimated at 14160 cases in 2008. and approximately 50% of such tumors will be diagnosed belatedly. Non-invasive and more reliable diagnostic procedures may enhance the number of early diagnoses. OBJECTIVES: 1) to describe difficulties of contact endoscopy related to mouth and lip (contact microstomatoscopy); 2) test the regular used criteria in other sites 3) describe objective parameters for applying Cellularity criterion; 4) compare diagnoses of contact microstomatoscopy in relation to lesions of the lower lip vermilion area (LVA) to anatomopathological diagnoses. CASUISTICS: 31 examinations were included in the Initial Study: 21 lip lesions and 10 oral lesions. In the Final Study, there were 69 examinations: 53 of lip vermilion area and 16 of lip mucosa with no lesion. METHODS: This study was prospective, the cases were not consecutive, the contact endoscope Storz 8715 A and toluidine blue were used. The experiment was divided into Initial Study (objectives 1 and 2) and Final Study (objectives 3 and 4). In the first study, oral and lip lesions were the focus, only in vivo examinations and without directed biopsy. In the second study, lower LVA lesions were the focus, only ex vivo cases related to and the biopsy was directed. The Cellularity criterion was divided into ranges in accordance with manual count of every malignant and benign lesion cells. Regression analyses and the Kendall`s correlation test were assessed. RESULTS: Lack of image clearness occurred in 100% of the cases; the criteria, when altered, defined malignancy through contact microstomatoscopy. In the Final Study, Kendall test was significant in relation to the criteria. Cellularity criterion was divided into four ranges: Minimum Risk (MNR) with less then 43 cells, Low Risk (LR) with 44 to 63 cells, Medium Risk (MR) with 64 to 83 cells, and High Risk (HR) with more than 84 cells. Regression analysis indicated that Stratification and Cellularity criteria, as well as both grouped ranges MNR and LR, were significant in relation to diagnosis of malignancy. False-negatives did not occur; in addition, false-positives represented 9.4%. Sensitivity to diagnosis of malignancy was 100%, 88% of specificity, 70.5% of positive predicted value, 100% of negative predictive value, and 90.3% of accuracy. CONCLUSION: Difficulties encountered (contact of the equipment with anatomic surface, sliding of the equipment, slight tremors, and lack of image clearness) did not stop the accomplishment of the procedure. All criteria were observed and correlated. The ranges MR and LR, when grouped, confirmed the significance of the division into ranges. Sensitivity and Specificity were high and presented good positive predictive value in relation to diagnosis of malignant lesions of lower lip vermilion area. This study suggests that contact microstomatoscopy may be applied to diagnosis of oral and lip lesions and, especially, of lower LVA
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CORRELAÇÃO ENTRE A NASOFIBROFARINGOSCOPIA E A CEFALOMETRIA NO DIAGNÓSTICO DE HIPERPLASIA DE TONSILAS FARÍNGEAS / CORRELATION BETWEEN NASOPHARYNGOSCOPY AND CEPHALOMETRY IN THE DIAGNOSIS OF HYPERPLASIA OF PHARYNGEAL TONSILSRitzel, Rodrigo Agne 01 March 2011 (has links)
Hyperplasia of the pharyngeal tonsil is one of the main causes of mouth
breathing. The accurate diagnosis of this alteration is important for proper
therapeutic planning. As a consequence, studies have been developed in order to
provide information about the procedures that can be used for the diagnosis of
pharyngeal obstruction. Objective: Verify the correlation between
nasopharyngoscopy and cephalometric exams in the diagnosis of pharyngeal tonsil
hyperplasia. Material and Methods: 55 children took part in this study, 30 girls and 25
boys, aged between seven and 11. The children were submitted to
nasofibropharyngoscopic and cephalometric evaluation to determine the grade of
nasopharyngeal obstruction. The Spearman's rank correlation coefficient at the 5%
significance level was used to verify the correlation of these exams. Results: In
nasopharyngoscopy, most children showed hyperplasia of the pharyngeal tonsil
grades 2 and 3, followed by grade1. In cephalometry, most children showed
hyperplasia of the pharyngeal tonsil grade 1, followed by grade 2. A regular positive
correlation was observed in the correlation between the exams. Conclusion: It was
concluded that the evaluation of the pharyngeal tonsil hyperplasia can be carried out
by fiberoptic nasopharyngoscopy and cephalometry, as these examinations present
a regular positive relation. However, it was found that cephalometry tends to
underestimate the size of the pharyngeal tonsil in relation to nasopharyngoscopy. / A hiperplasia de tonsila faríngea é uma das principais causas de respiração
oral. O diagnóstico preciso desta alteração é importante para o correto planejamento
terapêutico. Em vista disso, estudos têm sido desenvolvidos a fim de fornecer
subsídios quanto aos procedimentos que podem ser utilizados para o diagnóstico de
obstrução faríngea. Objetivo: Verificar a correlação entre os exames de
nasofibrofaringoscopia e cefalometria no diagnóstico de hiperplasia de tonsila
faríngea. Material e Métodos: Participaram deste estudo 55 crianças, 30 meninas e
25 meninos, com idades entre sete e 11 anos. As crianças foram submetidas à
avaliação nasofibrofaringoscópica e cefalométrica para a determinação do grau de
obstrução da nasofaringe. Para verificar a correlação entre esses exames foi
utilizado o coeficiente de correlação de Spearman ao nível de significância de 5%.
Resultados: Na nasofibrofaringoscopia a maioria das crianças apresentou
hiperplasia de tonsila faríngea graus 2 e 3, seguidas de grau 1. Na cefalometria a
maior parte das crianças apresentou hiperplasia de tonsilas faríngeas grau 1,
seguida de grau 2. Na correlação entre os exames, evidenciou-se correlação regular
e positiva. Conclusão: A avaliação da hiperplasia de tonsilas faríngeas pode ser
realizada pela nasofibrofaringoscopia e pela cefalometria, pois estes exames
apresentam uma relação regular e positiva. No entanto, verificou-se que a
cefalometria tende a subestimar o tamanho da tonsila faríngea em relação à
nasofibrofaringoscopia.
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Tratamento de varizes gástricas: mola e cianoacrilato versus cianoacrilato-estudo prospectivo randomizado / Treatment of gastric varices: coil plus cyanoacrylate versus cyanoacrylate alone. A randomized and prospective studyMaíra Ribeiro de Almeida Lôbo 24 March 2017 (has links)
A obliteração com cianoacrilato ainda é a técnica recomendada para tratamento das varizes gástricas, apesar do risco de embolia pulmonar. O tratamento ecoguiado com mola e cianoacrilato é uma alternativa recente, idealizado com o principal objetivo de diminuir a incidência de embolia. O presente estudo tem como objetivo comparar prospectivamente as duas técnicas quanto a incidência de complicações e a eficácia. Foram tratados pacientes com varizes gástricas pseudotumorais dos tipos GOV2 ou IGV1, em profilaxia primária ou secundária, sem tratamento endoscópico ou radiológico prévio. Os pacientes foram randomizados em dois grupos: grupo I - terapia ecoguiada com injeção de mola e cianoacrilato; grupo II - injeção não ecoguiada de cianoacrilato apenas. Tomografias computadorizadas para pesquisa de embolia foram realizadas em todos pacientes após o procedimento. Ecoendoscopia controle foi realizada com 1, 4 e 10 meses. O estudo foi realizado entre outubro de 2013 e novembro de 2016. O tempo médio de seguimento foi de 9,9 meses (1-26 meses). Foram avaliados 32 pacientes com idades entre 20 e 75 anos (média de 53,5 anos). Dezenove (59,4%) pacientes eram do sexo feminino. As etiologias da hipertensão portal mais encontradas foram a cirrose criptogênica, 7 (21,9%) e a hepatite C, 7 (21,9%). Vinte e cinco (78,1%) eram Child A e 7 (21,9%) Child B. Dezessete (53,1%) pacientes já tinham sangrado e 19 (59,4%) já haviam sido submetidos a tratamento endoscópico prévio de varizes esofágicas. Não houve diferença significante entre os dois grupos nas características acima citadas. Quanto aos achados endoscópicos e ecoendoscópicos, no grupo I, 13 (81,2%) pacientes apresentavam varizes gástricas do tipo GOV2 e 3 (18,8%) do tipo IGV1, números iguais aos achados no grupo II . O tamanho médio da variz gástrica foi de 3,62 cm ( ± 1,13) no grupo I e de 3,06 cm (± 0,88) no grupo II (p=0,131). A trombose imediata do vaso foi total em 6 (37,5%) pacientes no grupo I e em 8 (50%) pacientes no grupo II (p=0,476). No retorno em 30 dias, 11 (73,3%) pacientes no grupo I apresentavam ausência de fluxo no vaso tratado e 12 (75%) no grupo II (p=1). Quatro (26,7% e 25%) pacientes em cada grupo necessitaram de uma segunda sessão de tratamento em 30 dias (p=1). Após 4 meses, foi observada a trombose total do vaso tratado em 15 (100%) pacientes no grupo I e em 12 (80%) pacientes no grupo II (p=0,224). Dois (6,7%) pacientes foram a óbito no grupo II, sendo um decorrente de hemorragia digestiva alta e outro de sepse de foco indeterminado. No grupo I, 8 (50%) pacientes tiveram complicações precoces, sendo 4 (25%) casos de embolia pulmonar. No grupo II, 10 (62,5%) apresentaram complicações, com 8 (50%) casos de embolia . Não houve diferença significativa entre os dois grupos quanto ao índice de embolia pulmonar (p=0,144). Todos os pacientes que apresentaram embolia foram assintomáticos. Avaliando separadamente os pacientes com embolia pulmonar, não se observou diferença significante quanto ao grau de disfunção hepática, tipo da variz gástrica, número de sessões necessárias para a erradicação e a quantidade de ampolas de cianoacrilato utilizadas. Entretanto, o tamanho das varizes foi significativamente maior nos pacientes que tiveram embolia (3,85 cm ± 1,08) do que nos que não apresentaram essa complicação (3,04 cm ±0,9) (p=0,029). No grupo II, varizes maiores que 2,5 cm cursaram com maior incidência de embolia, com área sob a curva ROC de 0,836. O custo da injeção da mola com cianoacrilato foi significativamente maior que o do cianoacrilato (p < 0,001). Apesar da maior incidência de embolia no grupo I, não se observou significância estatística na comparação entre os dois grupos. A eficácia das duas técnicas se mostrou semelhante / In order to treat gastric varices, endoscopic obliteration using cyanoacrylate remains as the recommended technique, despite pulmonary embolism risk. EUS-guided coil treatment with cyanoacrylate is a recent alternative, designed with the main objective to decrease embolism incidence. This study aims at comparing these techniques regarding complication incidence and efficacy prospectively. Patients diagnosed with GOV2- or IGV1-pseudotumoral gastric varices were treated in primary or secondary prophylaxis, and no previous endoscopic or radiologic treatment. Patients were randomized into two groups: group I - EUS-guided coiling and cyanoacrylate injection treatment and group II - non EUS-guided cyanoacrylate injection alone treatment. Computed tomography was performed to identify embolism in all patients post-procedure. Control EUS examinations were performed at months 1, 4, and 10. This study was conducted from October 2013 to November 2016. Mean follow-up time was 9.9 months (1-26 months). Among the total of 32 patients aged 20 to 75 years old (mean age: 53.5 years) evaluated, 19 (59.4%) were female. Mostly found portal hypertension etiology was cryptogenic cirrhosis, in 7 (21.9%) patients, and hepatitis C virus, in 7 (21.9%). Twenty-five (78.1%) patients were categorized Child A and 7 (21.9%), Child B. Seventeen (53.1%) patients already presented with bleeding and 19 (59.4%) already underwent previous endoscopic esophageal variceal treatment. No significant difference between the two groups across the characteristics previously mentioned was found. Regarding endoscopic and ultrasound findings, in group I, 13 (81.2%) patients presented GOV2 gastric varices and 3 (18.8%), IGV1; whereas in group II, these same results were observed. Gastric variceal mean size was 3.62 cm (±1.13) in group I and 3.06 cm (±0.88) in group II (p=0.131). Immediate vessel thrombosis was found to be total in 6 (37.5%) patients from group I and in 8 (50%) from group II (p=0.476). At 30-day return visit, no flow in the treated vessel was verified in 11 (73.3%) patients from group I and 12 (75%) from group II (p=1). Four (26.7% and 25%) patients from both groups required second treatment session within 30 days (p=1). After 4 months, total thrombosis in the treated vessel was observed in 15 (100%) patients from group I and 12 (80%) from group II (p=0.224). Two (6.7%) group-II patients died: one from upper gastric hemorrhage and other from sepsis of undetermined focus. In group I, 8 (50%) patients presented early complications, 4 (25%) of them were cases of pulmonary embolism. In group II, 10 (62.5%) presented complications with 8 embolism cases. No significant difference between groups regarding pulmonary embolism index (p=0.144) was found. All embolism patients were asymptomatic. In a separate evaluation of pulmonary embolism patients, no significant difference was observed related to liver dysfunction degree, gastric varix type, number of sessions required for obliteration, and quantity of cyanoacrylate vials used. Nonetheless, variceal size was significantly higher in patients with embolism (3.85 cm ± 1.08) than in those with no such complication (3.04 cm ± 0.9) (p=0.029). In group II, varices larger than 2.5 cm evolved with higher incidence of embolism and the area under the ROC curve was found to be 0.836. Cost of coil injection with cyanoacrylate was significantly higher compared to cyanoacrylate alone (p < 0.001). Despite higher incidence of embolism in group I, no statistical significance in the comparison between groups was verified. Efficacy of both techniques was found to be similar
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Sedação em endoscopia digestiva alta: estudo comparativo com uso combinado de propofol e fentanil versus midazolam e fentanil / Randomized controlled trial comparing propofol and fentanyl versus midazolam and fentanyl for sedation in upper gastrointestinal endoscopySantos, Marcos Eduardo Lera dos 18 November 2011 (has links)
Introdução: o uso da sedação na rotina endoscópica tem sido empregado praticamente de maneira universal. O emprego de propofol parece se relacionar a exame mais confortável, com aumento da satisfação com o exame, pelo médico e pelo paciente. Entretanto, o uso do propofol está associado ao maior risco de sedação profunda e às complicações a ela associadas. Objetivo: comparar dois esquemas de sedação para a realização de endoscopia digestiva alta diagnóstica, grupo midazolam (midazolam e fentanil) com o grupo propofol (propofol e fentanil) quanto ao nível de sedação profunda e, como desfechos secundários, o grau de satisfação, o tempo de recuperação e a frequência de complicações entre os grupos. Método: foi realizado estudo experimental, prospectivo, randômico, cego com 200 pacientes, 100 no grupo midazolam e 100 no grupo propofol. Resultado: utilizando a escala OAA/S e o índice bispectral (BIS), respectivamente 11% e 7% dos pacientes do grupo midazolam e 25% e 19 % do grupo propofol apresentaram níveis de sedação profunda, sendo significativamente mais frequente neste último grupo. Houve boa correlação do nível de sedação da escala clínica OAA/S com o índice bispectral (BIS) para os dois grupos (k=0,63 para o grupo midazolam e k=0,71 para o grupo propofol). Quarenta e dois por cento dos pacientes do grupo propofol e 26% dos pacientes do grupo midazolam precisaram de oferta suplementar de oxigênio (p=0,025). O tempo médio de recuperação dos pacientes do grupo midazolam foi de 44,13 min e do grupo propofol foi de 28,82 min (p<0,001). O grau de satisfação dos pacientes foi semelhante entre os grupos e os médicos deram preferência ao uso da associação propofol/fentanil. Não se observaram complicações graves decorrentes da sedação em ambos os grupos. Conclusão: ambos os esquemas de sedação levam à sedação profunda. O grupo propofol utilizando o propofol e fentanil apresentou eventos de sedação profunda mais frequentemente. Por outro lado, os dois esquemas são seguros. Os pacientes do grupo propofol apresentaram tempo de indução da sedação, de recuperação e de liberação menores / Introduction: the use of sedation is almost universal for the practice of upper gastrointestinal (GI) endoscopy. The use of propofol seems to be associated with higher physician and patient satisfaction. However there is a higher risk of deep sedation and its related complication when propofol is used. Objective: compare the frequency of deep sedation events with two drug associations for the sedation in upper GI endoscopy. The OAA/S score and the bispectral index monitoring (BIS) were employed for the assessment of consciousness level. Secondarily we compared patient and physician satisfaction, recovery time and the complication rates between the two groups. Methods: two hundred patients sent for upper GI endoscopy were randomized in two groups: midazolam and propofol, each of them with 100 patients. Results: Deep sedation events occurred in 11% (OAA/S score) and 7% (BIS) in group midazolam and significantly more frequent in group propofol (25%- OAA/S score and 19% - BIS). There was a good agreement between the OAA/S score and the bispectral index (BIS) in both groups (k=0.63 and K=0.71 for groups midazolam and propofol, respectively). Forty two per cent of group propofol patients and 26% of group midazolam patients needed oxygen supplementation (p=0.025). The mean recovery time for groups midazolam and propofol patients were 44.13 min and 28.82 min, respectively (p<0.001). While patients were equally satisfied with both drug associations, physicians were more satisfied with the propofol/fentanyl association. We did not record any severe complications related with sedation. Conclusion: both drug associations are associated with deep sedation events. The propofol/fentanyl association causes deep sedation events more frequently when compared with midazolam/fentanyl association. Both associations are safe. The induction sedation, recovery and discharge times were shorter with propofol/fentanyl association
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Imagerie polarimétrique active par brisure d'orthogonalité / Active polarimetric imaging by orthogonality breaking sensingParnet, François 12 January 2018 (has links)
La polarisation de la lumière est très souvent utilisée en imagerie pour caractériser certaines propriétés de la matière, ou pour mettre en évidence des zones qui ne seraient peu ou pas contrastées avec des caméras d'intensité classiques. Nous explorons le potentiel d'une nouvelle technique de polarimétrie, dite de « brisure d'orthogonalité », pour réaliser des acquisitions de manière simple, directe et à haute cadence. Cette technique d'imagerie par balayage laser repose sur l'emploi d'une source de lumière bi-fréquence bi-polarisation pour sonder les caractéristiques polarimétriques (notamment le dichroïsme ou anisotropie d'absorption) des échantillons imagés.Nous explorons la possibilité du déport de la mesure de « brisure d'orthogonalité » par fibre optique faiblement multimode pour le développement d'endoscopes polarimétriques. Un tel dispositif vise à fournir une méthode de diagnostic rapide pour analyser des tissus biologiques profonds tout en évitant le recours aux biopsies. Nous démontrons, théoriquement et expérimentalement, la compatibilité de cette approche avec un dispositif d'endoscopie commercial (fibre ou bundle multicœurs, légèrement multimodes) pourvu que le nombre de modes guidés soit inférieur à une dizaine. D'autre part, nous présentons la conception, la réalisation, la validation et l'exploitation d'un démonstrateur d'imagerie active par brisure d'orthogonalité dans le proche infrarouge. Ce dernier vise des applications défense de détection et/ou décamouflage de cibles. Après caractérisation des bruits dominants les signaux acquis, nous illustrons l'apport du démonstrateur pour la mise en évidence d'éléments dichroïques. Enfin, nous démontrons que la technique de brisure d'orthogonalité peut être avantageusement, et très simplement, adaptée pour mesurer sélectivement le dichroïsme, la biréfringence, et la dépolarisation, paramètres essentiels à la détection d'objets manufacturés (cibles). Ces trois modalités, lorsqu'elles sont conjuguées, offrent au démonstrateur des capacités d'identification. / Polarimetric imaging is a useful tool to characterize some matter properties, or to highlight regions slightly or not contrasted with intensity cameras. We investigate the capability of a novel polarimetric technique, namely the “orthogonality breaking technique”, to perform direct and straightforward measurements at high speed. Relying on the use of a dual-frequency dual-polarization light source, this imaging modality probes polarimetric features (dichroism, or absorption anisotropy) in imaged samples.We explore the potential to perform orthogonality breaking measurements through few mode optical fibers towards polarimetric endoscopy. Such an imaging device would greatly improve the diagnosis efficiency to analyze in-depth biologic tissues without biopsy surgery. We show, theoretically and experimentally, the compatibility of our approach with a commercial flexible endoscope (slightly multimode multicore fibers or bundle) provided that the number of guided modes remains inferior to a dozen.On the other hand, we describe the design, the development, the validation and the exploitation of an active near infrared imaging demonstrator based on the orthogonality breaking technique for defense target detection applications. After characterization of the acquired signals noise, we illustrate the imager capability to reveal dichroic elements. Finally, we demonstrate that the orthogonality breaking technique can be advantageously and straightforwardly tailored to address selectively the dichroism, the birefringence and the depolarization, which are core parameters for the detection of manufactured objects (targets). The combination of these three modalities grants an identification capability to the demonstrator.
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Paquets d'Arthur des représentations cohomologiques / Arthur's Paquets of cohomological representationsArancibia-Robert, Nicolas-Jose 12 June 2015 (has links)
Cette thèse a pour objectif de montrer que les paquets de représentations cohomologiques d’un groupe réductif classique quasi déployé, défini sur R, construits par J. Arthur coïncident avec les paquets précédemments définis de manière plus élémentaire et plus explicite par Adams et Johnson... / The aim of this thesis is to prove that the packets of cohomological representation of quasi-split classical groups, defined over R, by Arthur coincide with the packets defined previously in a more elementary way by Adams and Johnson...
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Endoskopie zwischen Chirurgie und Gastroenterologie – aus der Sicht der Chirurgischen Arbeitsgemeinschaft für Endoskopie und Sonographie (CAES)Saeger, Hans Detlev January 2003 (has links)
Die Endoskopie ist ein wesentlicher Bestandteil der Chirurgie. Nicht nur die Diagnostik, sondern speziell die operative Endoskopie bedarf der besonderen Kompetenz von Chirurgen. Dies wurde in der Vergangenheit in einigen Zentren eindeutig belegt. Zukünftig wird die chirurgische Endoskopie in ihrer Wertigkeit steigen. Die konventionelle Chirurgie wird schon heute zum Teil durch minimal invasive Verfahren abgelöst. Die Progredienz dieser Entwicklung ist absehbar. Dazu werden auch Kombinationen der flexiblen Endoskopie mit laparoskopischen Techniken und der Sonographie zunehmend zum Einsatz kommen. Daneben wird die Kooperation mit den Gastroenterologen intensiviert. Ein kürzlich verabschiedetes Konsensuspapier der Deutschen Gesellschaft für Verdauungsund Stoffwechselkrankheiten und der Deutschen Gesellschaft für Viszeralchirurgie unterstreicht den bilateralen Wunsch zur Zusammenarbeit. Ziele bestehen in der Optimierung der endoskopischen Leistungen. Patientenversorgung, Forschung und Lehre können so synergistisch weiter verbessert werden. Die Voraussetzung zur Durchsetzung dieser Ziele ist die gegenseitige Anerkennung der Kompetenz, die Unterstützung bei der Novellierung der Weiterbildungsordnung und die dem Bedarf und den Fortschritten angepasste Weiterentwicklung des Papiers. Daneben werden Chirurgen und Gastroenterologen die fachspezifischen Fragestellungen der intraluminalen Endoskopie auch weiterhin selbständig verfolgen. / Endoscopy between Surgery and Gastroenterology – the Point of View of the Chirurgische Arbeitsgemeinschaft für Endoskopie und Sonographie (CAES) Flexible endoscopy is an important part of surgery. Not only diagnostic investigation, but especially operative endoscopy needs surgical competence. This has been proven in several centers. In the future the status of surgical endoscopy will increase. Already today, conventional surgery has been replaced more and more by minimal invasive procedures. This evolution probably will continue. The combination of flexible endoscopy with laparoscopy and sonography will be routinely introduced into daily surgical work. At the same time cooperation with medical gastroenterologists is intensified. A recently realized agreement of the German Society for Digestive and Metabolic Diseases and the German Society for Visceral Surgery confirms the efforts to work together in this field. The goal is to optimize endoscopic performance. Patient\'\'s care, research, and teaching can be synergistically improved. Conditions for successful consensual work are the acceptance of each others competence, the support of activities for actual education programs and the development of the agreement, depending on further necessities and progress. Besides that, specifically related research in intraluminal endoscopy will be continued by surgeons and medical gastroenterologists. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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Detecting gastrointestinal abnormalities with binary classification of the Kvasir-Capsule dataset : A TensorFlow deep learning study / Detektering av gastrointenstinentala abnormaliteter med binär klassificering av datasetet Kvasir-Capsule : En TensoFlow djupinlärning studieHollstensson, Mathias January 2022 (has links)
The early discovery of gastrointestinal (GI) disorders can significantly decrease the fatality rate of severe afflictions. Video capsule endoscopy (VCE) is a technique that produces an eight hour long recording of the GI tract that needs to be manually reviewed. This has led to the demand for AI-based solutions, but unfortunately, the lack of labeled data has been a major obstacle. In 2020 the Kvasir-Capsule dataset was produced which is the largest labeled dataset of GI abnormalities to date, but challenges still exist.The dataset suffers from unbalanced and very similar data created from labeled video frames. To avoid specialization to the specific data the creators of the set constructed an official split which is encouraged to use for testing. This study evaluates the use of transfer learning, Data augmentation and binary classification to detect GI abnormalities. The performance of machine learning (ML) classification is explored, with and without official split-based testing. For the performance evaluation, a specific focus will be on achieving a low rate of false negatives. The proposition behind this is that the most important aspect of an automated detection system for GI abnormalities is a low miss rate of possible lethal abnormalities. The results from the controlled experiments conducted in this study clearly show the importance of using official split-based testing. The difference in performance between a model trained and tested on the same set and a model that uses official split-based testing is significant. This enforces that without the use of official split-based testing the model will not produce reliable and generalizable results. When using official split-based testing the performance is improved compared to the initial baseline that is presented with the Kvasir-Capsule set. Some experiments in the study produced results with as low as a 1.56% rate of false negatives but with the cost of lowered performance for the normal class.
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Imagerie multispectrale pour améliorer la détection des lésions précancéreuses en endoscopie digestive / Multispectral imaging to improve the detection of precancerous lesions in digestive endoscopyMartinez Herrera, Sergio Ernesto 19 July 2016 (has links)
L'évolution de la gastrite et des lésions précancéreuses suit une cascade de plusieurs étapes. Les modifications des tissus pathologiques affichent de faibles variations par rapport à la muqueuse normale d'un point de vue macroscopique. Même si certaines variations pourraient être identifiées, cela reste fortement subjectif. Le diagnostic classique des maladies de l'estomac est divisé en deux procédures. Le premier est une gastroendoscopie où l'estomac est visuellement exploré sous une lumière blanche. Le second est la biopsie pour l'analyse histologique. Cette procédure a une forte probabilité d'établir le diagnostic correct mais il dépend fortement de la sélection correcte des échantillons de tissus endommagés. Ce travail porte sur l'étude de la muqueuse gastrique par imagerie multispectrale. La contribution principale est l'étude clinique de l'imagerie multispectrale afin de différencier les pathologies mal diagnostiquées ou qui ne peuvent être diagnostiquées que par l'analyse histologique. A cet effet, nous avons effectué (1) une étude ex-vivo dans un modèle de souris de l'infection de Helicobacter pylori dans le but d'identifier les longueurs d'onde qui pourraient être utilisées pour le diagnostic. (2) Nous proposons deux prototypes compatibles avec les gastroendoscopes actuels pour acquérir des images multispectrales du tissu gastrique : le premièr est basé sur une roue à filtres et le second sur une caméra multispectrale avec sept canaux. De plus, (3) nous présentons une méthodologie pour identifier les tissus pathologiques, qui est basé sur des caractéristiques statistiques extraites des spectres acquis, classées en fonction de leur pouvoir discriminants et une classification supervisée, où nous cherchons la meilleure performance de trois algorithmes de classification: le plus proche voisin, un réseaux de neurones et une Support Vector Machine avec une évaluation de la performance rigoureuse en utilisant une validation de type Leave One Patient Out Cross Validation. Les résultats démontrent la pertinence de l’imagerie multispectrale comme un outil supplémentaire pour un diagnostic objectif. / The evolution of gastritis into precancerous lesions follows a cascade of multiplestages. The modifications of the pathological tissues display low variations with respect to normal mucosa from a macroscopical point of view. Even though some features could be identified, they remain strongly subjective. The current gold standard for diagnosis of gastric diseases is divided in two procedures. The first one is gastroendoscopy where the stomach is visually explored under white light. The second one is biopsy collection for histological analysis. This procedure has a high probability of establishing the correct diagnosis but it strongly depends on the accurate collection of samples from damaged tissues. This doctoral work focuses on the study of gastric mucosa by multispectral imaging. The main contribution is the clinical study of multispectral imaging to differentiate pathologies poorly diagnosed or that can only be diagnosed by histological analysis. For this purpose, we performed (1) ex vivo studies in a mice model of infection of Helicobacter pylori in order to identify the wavelengths which could be used for diagnosis. (2) We propose two prototypes compatible with current gastroendoscopes to acquire multispectral images from gastric tissue: the first one is based on a filter wheel and the second one on a multispectral camera with seven channels. Additionally, (3) we present a methodology to identify pathological tissues, which is based on statistical features extracted from the acquired spectra, ranked according to their discriminative power and a supervised classification, where we search for the best performance of three classification algorithms: Nearest Neighbor, Neural Networks and Support Vector Machine with a rigorous performance evaluation by using leave one patient out cross validation. The results demonstrate the relevance of multispectral imaging as an additional tool for an objective diagnosis.
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