Sepsis-induced organ failure is associated with high morbidity and mortality rates. The onset of an exaggerated host response to microbial invasion and/or trauma, is believed to be the primary cause of excessive inflammation and the subsequent tissue hypoperfusion observed in patients with severe sepsis. In our mouse model of sepsis induced by cecal ligation and perforation (CLP), symptoms indicative of the disease, including diarrhea, increased ventilation and persistent hypothermia, are present at six hours after the surgery (T6). In the untreated CLP mice, mortality occurs starting at T15. As induced hypothermia has shown to exert immunomodulatory effects, this study is aimed at assessing its potential in attenuating inflammation and improving survival in experimental sepsis. Our data has shown that deep hypothermia initiated at T6, by means of cold chamber-induced cooling, prolongs survival. Plasma cytokine quantification by enzyme-linked immunosorbent assays (ELISA) also reveals that induced deep hypothermia reduces tumour necrosis factor(TNF)-α and interleukin (IL)-6 production in untreated CLP mice. In contrast, induced moderate hypothermia does not have such effect. Antibiotic (cefotaxime) and saline resuscitation initiated immediately following CLP ensures survival. However, when these supportive treatments are initiated at T6, >50% mortality is observed in the CLP mice with or without induced hypothermia. In summary, this preliminary study provides proof for a downregulated inflammatory response mediated by external cooling. However, to achieve a survival benefit, treatment strategies in addition to cooling and antibiotics may be required.

Introduction : La variabilité du rythme cardiaque est étudiée à partir des variations de durée des cycles cardiaques (intervalle R-R de l’électrocardiogramme). Ces variations peuvent être analysées par des méthodes linéaires (temporelles et fréquentielles) et non linéaires (théorie de l’information ou des fractales) de quantifications mathématiques et statistiques qui donnent des informations innovantes sur les signaux analysés. L’application de ces méthodes d’étude en néonatologie a démontré un intérêt pour le diagnostique précoce de l’infection néonatale tardive du prématuré mais n’avait pas été étudié dans l’infection néonatale précoce du nouveau-né à terme, dans le contexte des évènements cardio-respiratoires suivant la primo-vaccination des prématurés ou pour évaluer un effet neurologique de l’hyperbilirubinémie dans l’ictère néonatal. Notre hypothèse dans ce travail était qu’il était possible de : (i) caractériser la variabilité du rythme cardiaque en cas d’infection materno fœtale ou de méningite néonatale, (ii) mettre en évidence des facteurs prédisposant à la survenue d’évènements cardio-respiratoires post-vaccinaux, (iii) Identifier un éventuel retentissement neurologique de l’ictère néonatal par étude de la variabilité du rythme cardiaque. / The heart rate variability measures permitted to evaluate equilibrium state and perturbation in the regulation of cardio-vascular system.  These tools, based on heart rate variability analysis, helped to recognize associated disease state as early onset neonatal sepsis and non-infectious inflammatory response induced to immunization. An increase in global variability (SD), long term variability (SD, LF) and low approximated entropy (ApEn) were observed in the proven-sepsis full term infants. Importance of decrease in ApEn was correlated to the severity of sepsis assessed by blood markers. These suggest an association of sepsis with uncoordinated sympatho-vagal coactivation together with loss of adaptability. In premature infants, the risk of increase in cardio-respiratory events after the first immunization was associated with a specific pre-immunization profile: sympathetic predominance in heart rate control (high LF/HF ratio), abnormal oversimplification of heart rate variability and persistence rhythm control immaturity. Increased ApEn after immunization reflects a marginal result from adaptability of the heart rate to environmental changes without possibility to reserve in case of severe infection.

Background: Critically ill patients are at particular risk of developing bloodstream infection. Such infections are associated with the development of sepsis, leading to a marked increase in mortality rate. Early detection of the causative organism and appropriate antibiotic treatment are therefore critical for optimum outcome of patients with nosocomial infection. Current infection diagnosis is based on standard blood culture techniques. However, microbiological culture has a number of limitations, not least that it takes several days to confirm infection and is therefore not useful in directing the early treatment with antibiotics. New techniques based on the detection of pathogen DNA using real-time polymerase chain reaction (PCR) technology have the potential to address these limitations but their clinical utility is still to be proved. Objectives: Develop and evaluate novel PCR-based approaches to bloodstream infection diagnosis in critical illness based on detection and identification of bacterial and fungal DNA in blood. Methods: A range of commercial and 'in-house' PCR-based assays for detection of bacterial and fungal DNA were developed and/or optimised for use in clinical blood samples. These included LightCycler SeptiFast, a CE-marked multi-pathogen assay for common bloodstream pathogens, BactScreen and GramScreen, broad spectrum bacterial assays based on 16S rRNA gene and real-time PCR assays developed to detect a range of clinically important fungal pathogens. Novel approaches to speciation of pathogen DNA using melting temperature (Tm) profiling and high resolution melting analysis (HRMA) were developed. Clinical evaluation of assays was either on blinded clinical isolates or blood samples from critically ill patients with clinical suspicion of bloodstream infection against conventional microbiological culture. Several techniques aimed at improving extraction of pathogen DNA from blood were also investigated. Results: The CE-marked commercial assay SeptiFast showed analytical sensitivity and specificity of 79% and 83% respectively. Concordance with positive culture results was good but high levels of 'false positives' were detected possibly attributed to detection of free pathogen DNA not associated with viable pathogens. The predictive value of a negative SeptiFast test was 98% suggesting that absence of pathogen DNA is a strong indicator of absence of infection. Further studies were aimed at detailed optimisation and validation of 16S rRNA gene real-time PCR assays for bacterial DNA. BactScreen and GramScreen were able to detect a broad range of clinically important bacteria down to <50 CFU/ml blood. A preliminary comparative evaluation against SeptiFast showed BactScreen gave excellent concordance with blood culture results with minimal false positive results compared to SeptiFast. Efficient extraction of pathogen DNA was shown to be a key factor in determining analytical sensitivity and several protocols were evaluated. Low cost approaches to speciation of bacterial DNA were developed by combining broad range real-time PCR with HRMA. A novel HRMA method based on Tm profiling was shown to identify 89% and 96% of blinded clinical isolates at species or genus level respectively. Real-time PCR/HRMA approaches were also successfully developed for detection and identification of fungal pathogens including a range of Candida and Aspergillus species associated with bloodstream fungal infection. Conclusions: These studies have highlighted some of the key factors that need to be considered when developing and validating PCR based assays for pathogen DNA detection in blood. A set of novel tools have been developed for rapid detection and identification of bacterial and fungal pathogens that could address the challenges of infection diagnosis based on pathogen DNA detection. Further work is required, not least in development of more efficient pathogen DNA extraction and detailed clinical validation but the tools described here have the potential to provide cost effective solutions to aid infection diagnosis that would be complementary to current culture-based methods. The provision of time critical information could have a positive impact on clinical decision-making leading to more effective management and treatment of patients with suspected bloodstream infection.

No description available.

Orientadores: Maria Laura Costa do Nascimento, José Guilherme Cecatti / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-28T01:47:22Z (GMT). No. of bitstreams: 1 Pfitscher_LuciaChaves_M.pdf: 6366056 bytes, checksum: 9a70e9992cbec443ea7d924bdc77f7bb (MD5) Previous issue date: 2015 / Resumo: Introdução: A infecção representa importante causa de morbidade e mortalidade materna, sendo uma preocupação crescente no mundo todo. As doenças respiratórias, especialmente as virais, têm se destacado justamente pelo potencial de epidemia com que ameaçam a saúde da população mundial e pela vulnerabilidade identificada durante a gestação. Objetivo: Avaliar o impacto da morbidade materna grave (MMG) atribuível à infecção (sepse, meningite e doença respiratória) e os fatores associados ao pior resultado materno (near miss e óbito), entre mulheres da Rede Brasileira de Vigilância da Morbidade Materna Grave. Métodos: análise secundária de um estudo transversal, multicêntrico, que incluiu 27 centros de referência obstétrica das cinco regiões do Brasil no período de 2009 e 2010. A vigilância prospectiva dos casos de infecção grave foi realizada utilizando os critérios da OMS de condições potencialmente ameaçadoras da vida (CPAV) e near miss materno (NMM). Os principais focos de infecção foram identificados e comparados a outras causas de MMG. Mulheres com complicação devido à doença respiratória também foram avaliadas em dois grupos: com e sem suspeita de A(H1N1)pdm09 e também comparadas a outras causas de MMG. Casos com suspeita de A(H1N1)pdm09 foram revisados e separados em três grupos: não-testados, confirmados e não confirmados para A(H1N1)pdm09 e os seus resultados foram comparados. Complicações devidas à infecção e a doenças respiratórias foram comparadas com complicações devidas a outras causas de MMG. Os fatores associados com desfecho materno grave (DMG) foram avaliados para os casos de infecção e doença respiratória. Resultados: Dentre os 9555 casos de MMG, apenas 502 (5,3%) apresentaram infecção grave, entretanto foram responsáveis por cerca de um quarto dos casos de NMM e quase metade dos casos de morte materna (MM). Os indicadores de saúde avaliados demonstram maior gravidade dos casos complicados por infecção, com índice de mortalidade (IM) superior a 26% em comparação com 11% para as demais causas de MMG. Para doença respiratória, 206 mulheres apresentaram suspeita de A(H1N1)pdm09, cerca de 60% foram testados para a doença e 49 mulheres apresentaram resultado positivo. A gravidade dos desfechos maternos foi pior entre os casos de A(H1N1)pdm09 positivo, com uma taxa de NMM:MM abaixo de 1 (0,9:1), em comparação a 12:1 para outras causas de MMG. O IM para doença respiratória foi superior a 50% (7,4% outras causas de MMG). Demoras no atendimento foram associadas com pior prognóstico materno e estiveram presentes em mais de 50% entre os casos de infecção, aumentando em duas vezes o risco de DMG para doença respiratória. Resultados perinatais foram piores dentre os casos de doença respiratória, com aumento da prematuridade, morte fetal, baixo peso ao nascer e Apgar <7. HIV/AIDS, histerectomia, hospitalização prolongada, admissão em UTI e demoras no atendimento foram alguns fatores independentes associados DMG. Conclusão: complicações por infecção e em especial por influenza A(H1N1)pdm09 geram grande impacto sobre morbidade e mortalidade materna no Brasil e compreender os fatores associados à maior gravidade pode gerar medidas capazes de colaborar para a melhoria do cuidado obstétrico. Investir em intervenções específicas para gravidez, visando diagnóstico precoce e tratamento oportuno são essenciais para melhorar a saúde materna e reduzir o número de mortes maternas evitáveis no país / Abstract: Background: Infection represents the major cause of maternal morbidity and mortality, and a growing concern worldwide. Respiratory diseases, especially viral, have stood out because of their epidemic potential and the identified vulnerability towards infection during pregnancy. Objective: To assess the impact of severe maternal morbidity (SMM) due to infection (sepsis, meningitis and respiratory disease) and the factors associated with worse maternal outcome (near miss and death) among women of the Brazilian Network for the Surveillance of Severe Maternal Morbidity. Methods: secondary analysis of a cross-sectional, multicenter study that included 27 obstetric referral centers in five regions of Brazil between 2009 and 2010. Prospective surveillance of severe infection was performed using WHO criteria of potentially life threatening conditions (PLTC) and maternal near miss (MNM). The main sources of infection were identified and compared to other causes of SMM. Women with complications due to respiratory disease were also assessed in two groups: with and without suspected A(H1N1)pdm09 and also compared to other causes of SMM. Cases of suspected A(H1N1)pdm09 were reviewed and divided into three groups: non-tested, confirmed and unconfirmed for A(H1N1)pdm09 and their results were compared. Complications due to infection and respiratory disease were compared with complications due to other causes of SMM. Factors associated with SMO were assessed for cases of infection and respiratory disease. Results: Among the 9555 cases of SMM, only 502 (5.3%) had severe infection, however they were responsible for about a quarter of cases of MNM and almost half of the cases of maternal mortality (MM). The assessed health indicators demonstrate greater severity of cases complicated by infection, with a mortality index (MI) above 26% compared to 11% for other causes of SMM. For respiratory disease, 206 women had suspected A(H1N1)pdm09, about 60% were tested for the disease and 49 women were positive. The severity of the maternal outcomes was worse between the cases of A(H1N1)pdm09 positive, with a rate of MNM: MM below 1 (0.9: 1), compared to 12: 1 for other SMM causes. The MI among respiratory disease was superior to 50% (7.4% other causes SMM). Delays in care were associated with worse maternal prognosis and were present in over 50% of cases of infection. Perinatal results were worse in cases of respiratory disease, with increased prematurity, stillbirth, low birth weight and Apgar <7. HIV/AIDS, hysterectomy, prolonged hospitalization, ICU admission and delays in care were independent factors associated with severe maternal outcome. Conclusion: infections and especially those caused by A(H1N1)pdm09 presented great impact on maternal morbidity and mortality in Brazil and the identification of factors associated with the increased severity can contribute to the improvement of obstetric care. There is need for specific interventions during pregnancy, seeking early diagnosis and timely treatment of infections, which are essential for improving maternal health and to reducing the number of preventable maternal deaths in the country / Mestrado / Saúde Materna e Perinatal / Mestra em Ciências da Saúde

Submitted by Nadir Basilio (nadirsb@uninove.br) on 2015-07-20T14:24:42Z No. of bitstreams: 1 Sergio Antonio Pulzi Junior.pdf: 1595581 bytes, checksum: 4eafc8e1ef5004ab94c17237924403f2 (MD5) / Made available in DSpace on 2015-07-20T14:24:42Z (GMT). No. of bitstreams: 1 Sergio Antonio Pulzi Junior.pdf: 1595581 bytes, checksum: 4eafc8e1ef5004ab94c17237924403f2 (MD5) Previous issue date: 2014-11-24 / Introduction: The analysis of healthcare quality can be performed by assessing the care process. To this end, a broad concept of quality is necessary, which has three domains: structure, process and outcome. The exclusive assessment of outcome is somewhat interesting to evaluate efficiency and effectiveness. On the other hand, the evaluation of the care process is better to understand how healthcare services are carried out. Finally, the structure analysis allows realize how care is organized. In 1969, the Institute of Medicine expressed that specific diseases could be used as "tracers" to analyze healthcare services. This kind of evaluation could allow understanding the interplay among professionals, patients and the setting. Furthermore, it could provide information easy to understand and it would allow the development of suggestions that could be able to positively change the process of providing healthcare services. Purpose of research: This research aims to analyze the management of the care process using the sepsis as tracer disease of quality. The study was intended to understand whether this analysis would be able to contribute to the improvement of quality in the hospital setting. Results: After the selection of the study sample, the number of eighteen patients of a particular Brazilian public hospital was retrospectively evaluated. It was performed medical record review and the data collection was done in a specific research instrument. The adherence to quality indicators of the care process in sepsis, proposed by the Surviving Sepsis Campaign, was low: measure lactate level = 22%; blood cultures prior to administration of antibiotics = 33%; administer blood spectrum antibiotics = 28%; use of crystalloids or vasopressors = 72%; measurement central venous pressure = zero; measurement central venous oxygen saturation = 6%. Neither case had joint realization of all the items mentioned. Time indicators demonstrated that there was excess length of stay in the emergency department before hospitalization; delay in detection and diagnosis of sepsis; unavailability of beds in intensive care for immediate hospitalization. Furthermore, especially in surgical patients, there was a difficulty assessing specialized human resources and special facilities for diagnosis. Conclusion: The healthcare in sepsis appears to be sensitive to the quality of service delivery. This analysis allows the detection of care failures and to propose possible solutions. / Introdução: A análise de qualidade em saúde pode ser realizada pela avaliação do processo assistencial de um atendimento específico. Para tanto, é necessário um amplo conceito de qualidade, o qual possui três domínios: estrutura, processo e resultado. A avaliação exclusiva de resultado é pouco interessante para avaliar eficiência e efetividade. Por outro lado, medidas de processo são melhores e refletem como os serviços de saúde são realizados. Por fim, a análise de estrutura permite entender a maneira como o cuidado está organizado. Em 1969, o Institute of Medicine expressou que problemas específicos de saúde poderiam ser utilizados como “traçadores” para analisar serviços de saúde. Esse tipo de avaliação possibilitaria compreender a interação entre profissionais, paciente e ambiente. Além disso, seria capaz de fornecer informações de fácil compreensão, possibilitando a formulação de sugestões que pudessem modificar positivamente o processo de prestação de serviços em saúde. Objetivo da pesquisa: Assim, a presente pesquisa propõe a análise gerencial do processo assistencial utilizando a sepse como doença traçadora de qualidade. Pretende-se compreender se esta análise, seus resultados e conclusões seriam capazes de contribuir para a melhoria da qualidade no ambiente hospitalar. Resultados: Após seleção da amostra foram avaliados retrospectivamente 18 pacientes de um único hospital público brasileiro. Utilizou-se revisão de prontuários e coleta de dados em instrumento de pesquisa específico. A adesão aos indicadores de qualidade do processo assistencial da sepse, propostos pela Surviving Sepsis Campaign, foi baixa: coleta de lactato = 22%; coleta de hemoculturas = 33%; administração de antibióticos = 28%; uso de expansores ou vasopressores = 72%; medida de pressão venosa central = zero; medida da saturação venosa central de oxigênio = 6%. Em nenhum dos casos houve realização conjunta de todos os itens mencionados. Indicadores de tempo demonstraram que houve permanência prolongada do paciente no pronto socorro antes da internação hospitalar; atraso na percepção e no diagnóstico da sepse; indisponibilidade imediata de leito de terapia intensiva para internação. Além disso, especialmente em pacientes cirúrgicos, houve dificuldade de acesso a recursos humanos especializados e meios específicos para diagnóstico. Conclusão: O atendimento em sepse parece ser sensível à qualidade da prestação de serviços em saúde. Esta avaliação possibilitou a detecção de falhas de atendimento e a proposição de possíveis soluções.

Sepsis, commonly referred to as blood poisoning, is a serious medical condition characterized by a whole-body inflammatory state caused by microbial infection. Rapid treatment is crucial, however, traditional culture-based diagnostics usually takes 2-5 days.  The overall aim of the thesis is to develop microfluidic based sample preparation strategies, capable of isolating bacteria from whole blood for rapid sepsis diagnostics.  Although emerging technologies, such as microfluidics and “lab-on-a-chip” (LOC) devices have the potential to spur the development of protocols and affordable instruments, most often sample preparation is performed manually with procedures that involve handling steps prone to introducing artifacts, require skilled technicians and well-equipped, expensive laboratories.  Here, we propose the development of methods for fast and efficient sample preparation that can isolate bacteria from whole blood by using microfluidic techniques with potential to be incorporated in LOC systems. We have developed two means for high throughput bacteria isolation: size based sorting and selective lysis of blood cells. To process the large blood samples needed in sepsis diagnostics, we introduce novel manufacturing techniques that enable scalable parallelization for increased throughput in miniaturized devices. The novel manufacturing technique uses a flexible transfer carrier sheet, water-dissolvable release material, poly(vinyl alcohol), and a controlled polymerization inhibitor to enable highly complex polydimethylsiloxane (PDMS) structures containing thin membranes and 3D fluidic networks. The size based sorting utilizes inertial microfluidics, a novel particles focusing method that operates at extremely high flow rates. Inertial focusing in flow through a single inlet and two outlet, scalable parallel channel devices, was demonstrated with filtration efficiency of &gt;95% and a flowrate of 3.2 mL/min. Finally, we have developed a novel microfluidic based sample preparation strategy to continuously isolate bacteria from whole blood for downstream analysis. The method takes advantage of the fact that bacteria cells have a rigid cell wall protecting the cell, while blood cells are much more susceptible to chemical lysis. Whole blood is continuously mixed with saponin for primary lysis, followed by osmotic shock in water. We obtained complete lysis of all blood cells, while more than 80% of the bacteria were readily recovered for downstream processing. Altogether, we have provided new bacteria isolation methods, and improved the manufacturing techniques and microfluidic components that, combined offer the potential for affordable and effective sample preparation for subsequent pathogen identification, all in an automated LOC format. / QC 20120611

Articial intelligence has had a large impact on many industries and transformed some domains quite radically. There is tremendous potential in applying AI to the eld of medical diagnostics. A major issue with applying these techniques to some domains is an inability for AI models to provide an explanation or justication for their predictions. This creates a problem wherein a user may not trust an AI prediction, or there are legal requirements for justifying decisions that are not met. This thesis overviews how two explainable AI techniques (Shapley Additive Explanations and Local Interpretable Model-Agnostic Explanations) can establish a degree of trust for the user in the medical diagnostics eld. These techniques are evaluated through a user study. User study results suggest that supplementing classications or predictions with a post-hoc visualization increases interpretability by a small margin. Further investigation and research utilizing a user study surveyor interview is suggested to increase interpretability and explainability of machine learning results.

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