Thoracic injuries caused by blunt trauma are commonly encountered emergencies in veterinary medicine. However, no literature exists comparing radiography to computed tomography (CT) in blunt thoracic trauma caused by motor vehicle accidents in canine patients. The aim of this prospective case series was to estimate the sensitivity (Se) and specificity (Sp) of thoracic radiography relative to CT for detecting lung contusions, pneumothorax, pleural effusion and rib fractures. The study further aimed to establish a severity scoring system for radiography and CT and to compare the findings between the two modalities. The hypothesis was that radiography would be less sensitive than CT at detecting these injuries and that radiography would underestimate the severity of lung contusions compared to CT. Fifty-nine patients met the inclusion criteria. Radiography underestimated the presence of lung contusions (Se = 69%, 95% Confidence interval (CI)) and overestimated the severity of the contusions relative to CT. There was also high interobserver variability in evaluating lung contusion severity (coefficient of variation = 91%). Both the three-view thoracic and horizontal beam radiography had poor sensitivities for the detection of pneumothorax (Se = 19% and 63% respectively) and pleural effusions (Se = 43% and 71% respectively). Similarly, the sensitivity (56%) of three-view thoracic radiographs for the detection of rib fractures was poor relative to CT. To conclude, three-view thoracic radiography had low sensitivity for pathology related to blunt thoracic trauma caused by motor vehicle accidents and CT could be considered as an additional diagnostic imaging modality in these patients. / Dissertation (MMedVet (Diagnostic Imaging))--University of Pretoria, 2019. / Companion Animal Clinical Studies / MMedVet (Diagnostic Imaging) / Unrestricted

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13158号 / 論医博第2145号 / 新制||医||1029(附属図書館) / (主査)教授 川上 浩司, 教授 戸井 雅和, 教授 松田 秀一 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

Whether caused by trauma, internal diseases, or spontaneously; pneumothorax and hemothorax are potentially life threatening illnesses. They are currently primarily diagnosed with x-rays, CT scans, and ultrasound imaging. While these methods are generally reliable, they are not always available to the injured patient. Life threatening pneumothoraces, such as tension pneumothorax, must be treated quickly. When diagnosed correctly, pneumothorax and hemothorax can be quickly mended through insertion of chest tubes. X-rays, CT scans, and ultrasound imaging require large scale equipment and are not always dependable. There is a more reliable, portable, and faster result producing method to diagnose pneumothorax. Vibro-acoustic waves can be sent through the chest and the resulting wave can be measured. By analyzing attenuation characteristics determined by the geometry of the chest structures, it can be determined if the patient's pleural space is healthy, contains air (pneumothrax), or contains fluid (hemothorax).

Reproduction de : Thèse d'exercice : Médecine : Nancy 1 : 2004. / Titre provenant de l'écran-titre.

(Thesis: M.S.P.H.) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / INTRODUCTION: Although serious complications of invasive bedside procedures are rare they can be life threatening. Interest in identifying and preventing complications of bedside procedures has been heightened recently in light of such complications increasingly being linked to hospital reimbursement. In part I of this thesis we present the validation of ICD-9-CM codes for identification of the two most common complications associated with central venous catheterization. In part II we determine the impact of the development of a medical procedure service (MPS) on patient safety surrounding bedside procedures and resident education. METHODS: Part I: Cases of iatrogenic pneumothorax and central line associated blood stream infections (CLABSI) identified by ICD-9-CM codes in discharge data provided by Boston University Medical Center to the University HealthSystem Consortium were compared with those revealed by medical record abstraction of central venous catheters placed between 7/10-12/11. Part II: Retrospective cohort analysis of consecutive adults admitted to the internal medicine service who underwent a bedside medical procedure between 7/10-12/11 comparing characteristics and outcomes of procedures performed by the MPS versus primary services. RESULTS: Part I: The ICD-9-CM code for iatrogenic pneumothorax (512.1) had a sensitivity of 66.7%, specificity of 100%, positive predictive value of 100% and negative predictive value of 99.5%. The ICD-9-CM codes for CLABSI (999.31 and 999.32) had a sensitivity of 41.7%, specificity of 98.0%, positive predictive value of 20.0% and negative predictive value of 99.3%. Part II: We evaluated 1707 bedside procedures (548 by MPS, 1159 by primary services). While the MPS was more likely to successfully complete procedures (95.8% vs. 92.8%, p=0.02) and to use best practice safety process measures (95.4% vs. 51.0%, p<0.0001), the composite rate of major complications was similar (1.6% vs. 1.9%, p=0.71). CONCLUSIONS: Complications associated with invasive beside procedures are rare. The low sensitivity and variable positive predictive value of ICD-9-CM codes for detection of complications of central venous catheterization limits their use for internal quality improvement purposes. While use of a medical procedure service was associated with increased use of evidence based process measures, it did not significant affect the rate of major complications associated with bedside procedures. / 2031-01-01

Background: Tension pneumothorax is a condition with frequent fatal complications. This condition is caused by a disruption in the lung - that creates a one-way valve allowing air to accumulate in the pleural space. The fatal complication is the prevention of blood returning to the right side of the heart - due intrathoracic pressure compressing the right atrium. The patient can exhibit symptoms of dyspnea, tachypnea, tracheal deviation, jugular venous distention, subcutaneous emphysema, and shock that can lead to rapid deterioration and death. Case Report: We report a case of massive subcutaneous emphysema complicating tension pneumothorax management. The patient is a 20-year-old male who presented to the emergency department with chest trauma and was in extremis with diffuse severe subcutaneous emphysema. Due to the distorted anatomy, airway management and chest decompression were performed with nonstandard techniques/equipment resulting in rapid patient stabilization. After 4 days in the hospital, he was discharged home with no deficits. Discussion: Many providers do not have the proper equipment or training to treat patients in this extreme condition. CT images demonstrate the anatomical distortions in this case and the increase in size required for invasive life-saving devices. Images demonstrate where many commercial 14 gauge angiocaths and cricothyrotomy kits will not suffice (due to distortion in the anatomy), and these should not be relied on solely. Conclusions: While trauma carts frequently maintain (1.75 - 2 inch) 14 gauge angiocaths, they should also have military grade angiocaths that are 3.25” in length, which will work in most cases. Some, but not all, military-grade cricothyrotomy kits, or individually assembled kits, have 6.0 endotracheal tubes and come with a bougie and cricothyrotomy hook which would have been sufficient in this patient. Prehospital and hospital healthcare personnel should be prepared for similar patient encounters.

By taking advantage of the increasing amount of available electronic health data, applications of machine learning in the intensive care unit have the potential to improve medical diagnostics and risk stratification. This thesis proposes an approach for early onset prediction of pneumothorax with such technique, using time series data extracted from a clinical database. The prevalence of pneumothorax among patients is identified through ICD-9 codes, and labels for the onset are obtained by relying on proxies closely related to the condition. Both simple algorithms and deep learning networks are used in a sliding window-based prediction framework, and the importance of each feature is measured with weighted Shapley values. The results proved the feasibility of this approach using Long Short-Term Memory models, although the number of false positives is noticeably high. Mechanical ventilation was the most contributing feature for the outcome. In future work, the focus should be on addressing the large class imbalance that prevails, along with considering more well-founded methods of target labeling.

L’intoxication tabagique, source d’oxydants, est un facteur de risque important de développement de l’emphysème pulmonaire et du pneumothorax spontané primitif. Les macrophages alvéolaires contribuent pour une large part à l’inflammation pulmonaire au cours de ces pathologies en produisant des métalloprotéases et des espèces réactives de l’oxygène à l’origine du déséquilibre des balances protéase/anti-protéase et oxydant/antioxydant. L'hème oxygénase-1 (HO-1), exprimée principalement par les macrophages, est une enzyme clé des défenses anti-oxydantes pulmonaires. Nous avons initialement étudié l’expression et la localisation cellulaire de l’HO-1 et de ses régulateurs potentiels (Nrf2, Keap1, Bach1 et HIF-1a) dans les macrophages alvéolaires au cours de l’emphysème pulmonaire post-tabagique et du pneumothorax spontané primitif. Les voies de régulation de l’expression de ces protéines ont été analysées in vitro sur des macrophages dérivés de la lignée THP-1 exposés ou non au condensat de fumée de cigarette et à l’hypoxieréoxygénation visant à mimer une partie des effets de l’atélectasie-réexpansion observée lors de la prise en charge thérapeutique des pneumothorax récidivants. Les travaux présentés dans cette thèse nous ont permis de mettre en évidence une altération de l’expression de la voie Nrf2/Keap1-Bach1 associée à une diminution de l’expression des enzymes anti-oxydantes, dont l’HO-1, dans les macrophages alvéolaires au cours de l’emphysème pulmonaire sévère post-tabagique, malgré un stress oxydant important. In vitro, ces altérations pourraient être liées à une activation spécifique des MAPKinases ERK1/2 et JNK par le condensat de fumée de cigarette. Nous avons également montré que la stimulation du système de l’HO-1 était probablement orchestrée par la voie du facteur HIF-1a, et non par celle de Nrf2, dans les macrophages alvéolaires au cours du pneumothorax spontané primitif récidivant du sujet fumeur. Ces résultats pourraient contribuer à une meilleure connaissance de la physiopathologie de l’emphysème pulmonaire et permettre d’envisager de nouvelles approches thérapeutiques basées sur la préservation et/ou la restauration de l’équilibre Nrf2/Keap1-Bach1. Nos travaux suggèrent également que la physiopathologie du pneumothorax spontané primitif est différente chez les patients fumeurs et non fumeurs. Le pneumothorax du sujet fumeur est associé à un stress oxydant pulmonaire et à une induction de l’HO-1 probablement orchestrée par HIF-1a. Ces résultats, confirmés in vitro, mettent en évidence une interaction potentielle entre le stress oxydant et l’hypoxie-réoxygénation / Chronic cigarette smoking, a source of oxidants, is an important risk factor for lung emphysema and primary spontaneous pneumothorax development. Alveolar macrophages are mainly involved in lung inflammation observed in these pathologies through the production of metalloproteases and reactive oxygen species resulting to protease/anti-protease and oxidant/anti-oxidant imbalances. Heme oxygenase-1 (HO-1), mainly expressed in macrophages, is a key enzyme in pulmonary anti-oxidant defences. Therefore, the first aim of our studies was to investigate the expression and cellular localisation of HO-1 and its potential regulators (Nrf2, Keap1, Bach1 and HIF-1a) in alveolar macrophages from smoking related lung emphysema and primary spontaneous pneumothorax. Regulation pathways involved in expression of these proteins were assessed in vitro in macrophage cell line THP-1 exposed or not to cigarette smoke condensate and with or without hypoxia-reoxygenation mimicking parts of events induced by atelectasia-reexpansion during recurrent pneumothorax constitution and treatment. In these studies, we showed an altered expression of Nrf2/Keap1- Bach1 pathway associated with a reduced expression of anti-oxidants enzymes, like HO-1, in alveolar macrophages from smoking related lung emphysema patients, despite an important oxidative stress. These alterations might be related to cigarette smoke condensate activated ERK1/2 and JNK MAPKinases as observed in THP-1 cells. Furthermore, we showed that HO- 1 system induction was mediated by HIF-1a instead of Nrf2 pathway in alveolar macrophages from smoking related recurrent primary spontaneous pneumothorax. These findings may contribute to a better knowledge of the pathophysiology of lung emphysema and could provide new therapeutic approaches based on preservation and/or restoration of Nrf2/Keap1-Bach1 equilibrium. Our results also suggest that the pathophysiology of primary spontaneous pneumothorax could be different in smokers and non smokers. Spontaneous pneumothorax in smokers is associated with lung oxidative stress and the orchestrated induction of HO-1 probably via HIF-1a. These results provide a new link between oxidative stress and hypoxia/reoxygenation

Introdução: Pneumotórax é uma complicação comum em pacientes sob ventilação mecânica. Se não reconhecido, tende a aumentar de volume e pode levar ao colapso cardiovascular. Os métodos utilizados para seu diagnóstico caracterizam-se por baixa sensibilidade (radiografia) ou envolvem transporte potencialmente arriscado à tomografia de raios X. A tomografia de impedância elétrica (TIE) é um método não invasivo que permite monitorização da ventilação em tempo real. O método é baseado na construção da imagem de uma seção transversal das condutividades torácicas através de eletrodos dispostos ao redor do tórax. A TIE correlaciona-se muito bem com as alterações regionais do conteúdo de ar dentro do tórax. Por ter baixo custo, não ser invasiva e ter alta sensibilidade às alterações da ventilação e aeração pulmonar, a TIE é um método promissor para a detecção de pneumotóraces em situações de alto risco. Os objetivos deste estudo foram: 1) caracterizar as alterações na TIE relacionadas ao aparecimento de pneumotórax; 2) desenvolver um algoritmo para detecção automática de pneumotóraces e 3) avaliar prospectivamente a sensibilidade e especificidade deste algoritmo. Métodos: Foram realizados experimentos em 39 porcos (peso médio 31,0 Kg ± 3,2 desvios-padrão). Os animais foram sedados e submetidos à ventilação mecânica. Os dados de TIE foram adquiridos através de um tomógrafo de impedância desenvolvido por nosso grupo (Laboratório de Pneumologia Experimental, Escola Politécnica da Universidade de São Paulo e Dixtal Biomédica Ltda., São Paulo, Brasil), capaz de produzir 50 imagens relativas por segundo. Um primeiro grupo de dez animais foi submetido à drenagem torácica com indução progressiva de pneumotórax através do dreno (de 0 a 500 mL). No grupo seguinte, induzimos lesão pulmonar através de lavagem com salina em oito animais e os submetemos a mudanças progressivas de PEEP. Essas duas primeiras etapas foram utilizadas para a construção de um detector automático de pneumotórax baseado na TIE que foi testado prospectivamente em outros 21 animais. Resultados: A TIE apresenta alterações bem definidas relacionadas ao surgimento de pneumotórax, caracterizadas por aumento da impedância média e diminuição da amplitude da impedância concentrados no quadrante de interesse. Por outro lado, os achados na TIE durante mudanças bruscas de PEEP se distribuíram homogeneamente nos quatro quadrantes. A TIE apresentou alterações significativas mesmo com os menores volumes de ar injetados (20 mL), enquanto as demais variáveis monitorizadas foram pouco sensíveis ao surgimento do pneumotórax. A pressão arterial teve uma pequena queda com volumes superiores a 500 mL, e a pressão parcial de oxigênio arterial diminuiu somente com volumes maiores que 100 mL. Na fase prospectiva do protocolo, a TIE mostrou sensibilidade de 100% e especificidade de 95% para a detecção de pneumotóraces. A localização do pneumotórax foi identificada corretamente em todos os casos. Conclusão: A TIE apresenta alterações reprodutíveis relacionadas ao aparecimento de ar no espaço pleural caracterizadas por aumento da impedância média e diminuição da amplitude de impedância. Foi possível criar um algoritmo baseado nessas alterações capaz de detectar precoce e precisamente pneumotóraces em situações de risco. O processo de detecção é automático e em tempo real. / Introduction: Pneumothorax is a frequent complication during mechanical ventilation. Electrical impedance tomography (EIT) is a noninvasive tool that allows real-time imaging of regional ventilation. The purpose of this study was to: 1) identify characteristic changes in the EIT signals associated with pneumothoraces; 2) develop and fine-tune an algorithm for their automatic detection; and 3) prospectively evaluate this algorithm for its sensitivity and specificity in detecting pneumothoraces in real time. Methods: prospective controlled laboratory animal investigation. Setting: Experimental Pulmonology Laboratory of the University of Sao Paulo. Subjects: 39 anesthetized mechanically ventilated supine pigs (31.0 ± 3.2Kg, mean ± standard deviation). Interventions: In a first group of 18 animals monitored by EIT, we either injected progressive amounts of air (from 20 up to 500 mL) through chest tubes, or we applied large PEEP increments to simulate extreme lung overdistension. This first data set was used to calibrate an EIT-based pneumothorax detection algorithm. Subsequently, we evaluated the real-time performance of the detection algorithm in 21 additional animals (with normal or pre-injured lungs), submitted to multiple ventilatory interventions or traumatic punctures of the lung. Results: primary EIT relative images were acquired on-line (50 images/second) and processed according to a few imaging-analysis routines running automatically and in parallel. Pneumothoraces as small as 20mL could be detected with a sensitivity of 100% and specificity 95% and easily distinguished from parenchymal overdistension induced by PEEP or recruiting maneuvers. Their location was correctly identified in all cases, with a total delay of only 3 respiratory cycles. Conclusion: We created an EIT-based algorithm capable of detecting early signs of pneumothoraces in high-risk situations, which also identifies its location. It requires that the pneumothorax occurs or enlarges at least minimally during the monitoring period. Such detection was operator-free and in quasi real-time, opening opportunities for improving patient safety during mechanical ventilation.

Introdução: Pneumotórax é uma complicação comum em pacientes sob ventilação mecânica. Se não reconhecido, tende a aumentar de volume e pode levar ao colapso cardiovascular. Os métodos utilizados para seu diagnóstico caracterizam-se por baixa sensibilidade (radiografia) ou envolvem transporte potencialmente arriscado à tomografia de raios X. A tomografia de impedância elétrica (TIE) é um método não invasivo que permite monitorização da ventilação em tempo real. O método é baseado na construção da imagem de uma seção transversal das condutividades torácicas através de eletrodos dispostos ao redor do tórax. A TIE correlaciona-se muito bem com as alterações regionais do conteúdo de ar dentro do tórax. Por ter baixo custo, não ser invasiva e ter alta sensibilidade às alterações da ventilação e aeração pulmonar, a TIE é um método promissor para a detecção de pneumotóraces em situações de alto risco. Os objetivos deste estudo foram: 1) caracterizar as alterações na TIE relacionadas ao aparecimento de pneumotórax; 2) desenvolver um algoritmo para detecção automática de pneumotóraces e 3) avaliar prospectivamente a sensibilidade e especificidade deste algoritmo. Métodos: Foram realizados experimentos em 39 porcos (peso médio 31,0 Kg ± 3,2 desvios-padrão). Os animais foram sedados e submetidos à ventilação mecânica. Os dados de TIE foram adquiridos através de um tomógrafo de impedância desenvolvido por nosso grupo (Laboratório de Pneumologia Experimental, Escola Politécnica da Universidade de São Paulo e Dixtal Biomédica Ltda., São Paulo, Brasil), capaz de produzir 50 imagens relativas por segundo. Um primeiro grupo de dez animais foi submetido à drenagem torácica com indução progressiva de pneumotórax através do dreno (de 0 a 500 mL). No grupo seguinte, induzimos lesão pulmonar através de lavagem com salina em oito animais e os submetemos a mudanças progressivas de PEEP. Essas duas primeiras etapas foram utilizadas para a construção de um detector automático de pneumotórax baseado na TIE que foi testado prospectivamente em outros 21 animais. Resultados: A TIE apresenta alterações bem definidas relacionadas ao surgimento de pneumotórax, caracterizadas por aumento da impedância média e diminuição da amplitude da impedância concentrados no quadrante de interesse. Por outro lado, os achados na TIE durante mudanças bruscas de PEEP se distribuíram homogeneamente nos quatro quadrantes. A TIE apresentou alterações significativas mesmo com os menores volumes de ar injetados (20 mL), enquanto as demais variáveis monitorizadas foram pouco sensíveis ao surgimento do pneumotórax. A pressão arterial teve uma pequena queda com volumes superiores a 500 mL, e a pressão parcial de oxigênio arterial diminuiu somente com volumes maiores que 100 mL. Na fase prospectiva do protocolo, a TIE mostrou sensibilidade de 100% e especificidade de 95% para a detecção de pneumotóraces. A localização do pneumotórax foi identificada corretamente em todos os casos. Conclusão: A TIE apresenta alterações reprodutíveis relacionadas ao aparecimento de ar no espaço pleural caracterizadas por aumento da impedância média e diminuição da amplitude de impedância. Foi possível criar um algoritmo baseado nessas alterações capaz de detectar precoce e precisamente pneumotóraces em situações de risco. O processo de detecção é automático e em tempo real. / Introduction: Pneumothorax is a frequent complication during mechanical ventilation. Electrical impedance tomography (EIT) is a noninvasive tool that allows real-time imaging of regional ventilation. The purpose of this study was to: 1) identify characteristic changes in the EIT signals associated with pneumothoraces; 2) develop and fine-tune an algorithm for their automatic detection; and 3) prospectively evaluate this algorithm for its sensitivity and specificity in detecting pneumothoraces in real time. Methods: prospective controlled laboratory animal investigation. Setting: Experimental Pulmonology Laboratory of the University of Sao Paulo. Subjects: 39 anesthetized mechanically ventilated supine pigs (31.0 ± 3.2Kg, mean ± standard deviation). Interventions: In a first group of 18 animals monitored by EIT, we either injected progressive amounts of air (from 20 up to 500 mL) through chest tubes, or we applied large PEEP increments to simulate extreme lung overdistension. This first data set was used to calibrate an EIT-based pneumothorax detection algorithm. Subsequently, we evaluated the real-time performance of the detection algorithm in 21 additional animals (with normal or pre-injured lungs), submitted to multiple ventilatory interventions or traumatic punctures of the lung. Results: primary EIT relative images were acquired on-line (50 images/second) and processed according to a few imaging-analysis routines running automatically and in parallel. Pneumothoraces as small as 20mL could be detected with a sensitivity of 100% and specificity 95% and easily distinguished from parenchymal overdistension induced by PEEP or recruiting maneuvers. Their location was correctly identified in all cases, with a total delay of only 3 respiratory cycles. Conclusion: We created an EIT-based algorithm capable of detecting early signs of pneumothoraces in high-risk situations, which also identifies its location. It requires that the pneumothorax occurs or enlarges at least minimally during the monitoring period. Such detection was operator-free and in quasi real-time, opening opportunities for improving patient safety during mechanical ventilation.