<p>Because of the difficulties in concluding whether a person has drowned or not, information that could be relevant for postmortal diagnosis of drowning was studied. With postmortal CT images lung volume, mean attenuation, anterior-posterior difference, lung density profile and amount of water within the lungs were investigated.</p><p>The report also evaluates three examples of software that calculates lung volume from postmortal CT images: Siemens’ Syngo Pulmo CT, Siemens‘ Volume Evaluation and GE Medical Systems’ Volume Viewer. The method used at autopsy was also studied. The repeatability and validity were tested and sources of errors identified.</p><p>Repeatability and validity for the three tested types of software were acceptable, while the method used at autopsy had to be improved. The study also showed that lung volume related to length, anterior-posterior difference and lung density profile seemed to vary between drowned and other deceased. These measures might conclude whether a person has drowned.</p>

Because of the difficulties in concluding whether a person has drowned or not, information that could be relevant for postmortal diagnosis of drowning was studied. With postmortal CT images lung volume, mean attenuation, anterior-posterior difference, lung density profile and amount of water within the lungs were investigated. The report also evaluates three examples of software that calculates lung volume from postmortal CT images: Siemens’ Syngo Pulmo CT, Siemens‘ Volume Evaluation and GE Medical Systems’ Volume Viewer. The method used at autopsy was also studied. The repeatability and validity were tested and sources of errors identified. Repeatability and validity for the three tested types of software were acceptable, while the method used at autopsy had to be improved. The study also showed that lung volume related to length, anterior-posterior difference and lung density profile seemed to vary between drowned and other deceased. These measures might conclude whether a person has drowned.

ABSTRACT Rationale: Respiratory insufficiency is one of the most common causes of death in patients with neuromuscular disorders (NMD). Due to weakness and cognitive level, children with NMD often cannot perform required maneuvers to recruit lung volume. Data from cooperative adults suggest that breath stacking with a mask and one-way valve can obtain significantly higher lung volumes. Methods: To study the effectiveness of a breath stacking mask in patients with NMD, we studied 23 children (17 male, 6 female) over 3 years, mean age 11 y (range 3-19 y) and body mass 43.8 kg (range 12-80 kg). Fifteen were cognitively aware and able to communicate verbally. For involuntary breath stacking a one-way valve and pneumotach were attached to a cushioned mask that was held to the face, covering around nose and mouth with a tight seal. Flow signals were acquired to computer (AcqKnowledge BIOPAC Inc.). Tidal volumes (Vt) and minute ventilation (VE) were calculated from the recording for 30 s before and 30 s after 15 s of valve closure during which expiration was prevented. Oxygen saturation (SaO2) was measured. Results: The mean Vt before valve closure was 277 ml (range 29-598 ml). The mean increase in volume by stacking was 599 ± 558 ml (range -140 to 2,916 ml). When normalized to body mass, mean increase above normal end inspiratory level was 14.7 ± 14.7 ml/kg (range -2.7 to 52.2 ml/kg). The mean number of stacked breaths was 4.5 ± 3.6 (range 0-17). VE increased on average by 18% after stacking (p<0.05, paired t-test). There was no change in SaO2 after stacking. Four of the 23 children did not stack. Conclusions: Our findings show that breath stacking with a mask and a one-way valve can achieve breath volumes approximately 3x Vt. The mask was tolerated well, and cooperation of the child was not required.

ABSTRACT Rationale: Respiratory insufficiency is one of the most common causes of death in patients with neuromuscular disorders (NMD). Due to weakness and cognitive level, children with NMD often cannot perform required maneuvers to recruit lung volume. Data from cooperative adults suggest that breath stacking with a mask and one-way valve can obtain significantly higher lung volumes. Methods: To study the effectiveness of a breath stacking mask in patients with NMD, we studied 23 children (17 male, 6 female) over 3 years, mean age 11 y (range 3-19 y) and body mass 43.8 kg (range 12-80 kg). Fifteen were cognitively aware and able to communicate verbally. For involuntary breath stacking a one-way valve and pneumotach were attached to a cushioned mask that was held to the face, covering around nose and mouth with a tight seal. Flow signals were acquired to computer (AcqKnowledge BIOPAC Inc.). Tidal volumes (Vt) and minute ventilation (VE) were calculated from the recording for 30 s before and 30 s after 15 s of valve closure during which expiration was prevented. Oxygen saturation (SaO2) was measured. Results: The mean Vt before valve closure was 277 ml (range 29-598 ml). The mean increase in volume by stacking was 599 ± 558 ml (range -140 to 2,916 ml). When normalized to body mass, mean increase above normal end inspiratory level was 14.7 ± 14.7 ml/kg (range -2.7 to 52.2 ml/kg). The mean number of stacked breaths was 4.5 ± 3.6 (range 0-17). VE increased on average by 18% after stacking (p<0.05, paired t-test). There was no change in SaO2 after stacking. Four of the 23 children did not stack. Conclusions: Our findings show that breath stacking with a mask and a one-way valve can achieve breath volumes approximately 3x Vt. The mask was tolerated well, and cooperation of the child was not required.

The clinical usage of Seismocardiography (SCG) is increasing as it is being shown to be an effective non-invasive measurement for heart monitoring. SCG measures the vibrational activity at the chest surface and applications include non-invasive assessment of myocardial contractility and systolic time intervals. Respiratory activity can also affect the SCG signal by changing the hemodynamic characteristics of cardiac activity and displacing the position of the heart. Other clinically significant information, such as systolic time intervals, can thus manifest themselves differently in an SCG signal during inspiration and expiration. Grouping SCG signals into their respective respiratory cycle can mitigate this issue. Prior research has focused on developing machine learning classification methods to classify SCG events as according to their respiration cycle. However, recent research at the Biomedical Acoustics Research Laboratory (BARL) at UCF suggests grouping SCG signals into high and low lung volume may be more effective. This research aimed at com- paring the efficiency of grouping SCG signals according to their respiration and lung volume phase and also developing a method to automatically identify the respiration and lung volume phase of SCG events.

Le Syndrome de détresse respiratoire aiguë (SDRA) est une pathologie fréquente et grave. Son traitement fait appel à la ventilation mécanique qui est indispensable pour maintenir une oxygénation suffisante mais elle peut induire des lésions pulmonaires responsables d'une morbidité importante. Le volume pulmonaire est diminué au cours du SDRA ; sa mesure a longtemps été du domaine de la recherche clinique mais une technique de mesure au lit du patient a récemment été proposée : le lavage de l'azote. Ce travail avait pour but de tester la mesure du volume pulmonaire par la technique du lavage de l'azote dans des conditions d'utilisation comparables à celles du SDRA c'est à dire avec des niveaux de pression expiratoire positive (PEP) et de FiO2 élevés. Une fois cette étape préliminaire validée, nous avons utilisé la mesure du volume pulmonaire pour évaluer le recrutement induit par des réglages de PEP différents et lors de changements de position.Nous avons montré dans l'étude n°1 que les mesures étaient suffisamment précises et reproductibles pour une utilisation clinique. La PEP et le niveau d'oxygénation influençaient peu les mesures. Dans l'étude n°2, le recrutement induit par une PEP de type « recrutement maximal » réglée pour obtenir une pression de plateau (Pplat) entre 28 et 32 cmH2O, a été estimé à partir des mesures de volume pulmonaire comparées à l'augmentation minimale prédite du volume pulmonaire. Une bonne corrélation avec le recrutement mesuré par la technique des courbes pression - volume était trouvée sous réserve d'une élimination des mesures incohérentes.Parallèlement, la mesure du volume pulmonaire et l'oxygénation de patients en SDRA et Acute Lung Injury (ALI) ont été analysées lors de changements de position (Position demi-assise puis assise). Cette étude montre que le volume pulmonaire est augmenté lors de la verticalisation et particulièrement chez les patients augmentant leur oxygénation > 20%. Les patients ne répondant pas au positionnement avaient des volumes pulmonaires plus élevés et qui variaient peu.Les différents travaux réalisés ont permis de montrer la simplicité d'utilisation de la technique. Ceci offre des perspectives de recherche au lit du patient plus accessibles qu'avec les techniques de référence (scanner et dilution de l'hélium), et également des perspectives cliniques. Une approche de la déformation pulmonaire induite par la ventilation (strain) et potentiellement des lésions induites par la ventilation mécanique est rendue possible par la mise à disposition en clinique de cette technique. / The acute respiratory distress syndrome (ARDS) is a frequent and severe form of acute respiratory failure. Mechanical ventilation is the cornerstone of treatment but it may induce a specific form of lung injury (Ventilator induced Lung Injury) responsible for superimposed morbidity and mortality. Lung volume is dramatically decreased during ARDS. Lung volume measurements remained limited to clinical research until recently when the nitrogen washout/washin technique has been adapted for bedside use and implemented in an intensive care ventilator. The aim of this work was to test the nitrogen washout/washin method in clinical conditions of ARDS treatment with high Positive End Expiratory Pressure (PEEP) and high oxygen fraction (FiO2). Once this preliminary validation study was realised, we used the technique to assess the amount of lung recruitment induced by PEEP and positioning.We showed in the first study that accuracy and reproducibility of the technique were acceptable. PEEP and FiO2 had a minor influence on measurements. In the second study, the recruitment induced by a “maximal recruitment” PEEP set to obtain a plateau pressure between 28-32 cmH2O has been estimated using end-expiratory lung volume (EELV) measurements. A significant correlation was found between the recruitment measured on Pressure/Volume curves and the recruitment estimated comparing the predicted minimal increase in lung volume and the true increase in EELV.In a third study, we have evaluated the concomitant effects of verticalization on EELV and oxygenation following a change from supine to semi recumbent, seated and back to supine position. In this third study, verticalization (seated position) resulted in a significant concomitant increase in lung volume and oxygenation. Interestingly, patients responding to verticalization had lower EELV at baseline than non-responders. Only the group of patients increasing their PaO2/FiO2>20% during verticalization had a significant increase in their EELV compared to non-responders.These three studies confirmed the feasibility of the technique, easier than the gold standard techniques (helium dilution or CT scan), and offering both research and clinical perspectives. This technique should also allow an easier approach of the strain induced by ventilation and assess the risk of ventilation induced lung injury.

A Tomografia de Impedância Elétrica (TIE) é um método de imagem que permite estudarmos alterações regionais de ventilação pulmonar com alta resolução temporal. Estudamos a influência da posição corporal e do esforço expiratório no esvaziamento regional pulmonar comparando dados de espirometria com os da TIE adquiridos simultaneamente. MÉTODOS: Oito voluntários monitorados continuamente com TIE, realizaram manobras de capacidade vital lenta (CVL) com washout de nitrogênio (WN2) e capacidade vital forçada (CVF) nas posições sentado, decúbito lateral direito (DLD) e esquerdo (DLE). Em todas as posições, comparamos a variação global de impedância (Z) com os volumes da espirometria. Analisamos também as variações regionais de volume do pulmão direito e esquerdo, em cada posição, e a cada 10% da expiração total através da TIE; estes dados foram comparados com análise do WN2. RESULTADOS: Na espirometria e na TIE, houve uma redução no volume total expirado na CVF e na CVL dos decúbitos laterais quando comparados à posição sentada (P = 0,001). Na análise da CVL através da TIE, observamos um fluxo maior no pulmão dependente (de 2 a 10 vezes maior), em ambos os decúbitos laterais, com inversão deste padrão aproximadamente na metade da capacidade vital. Já na CVF o Z foi semelhante entre os pulmões ao longo da expiração, independente do decúbito, semelhante à situação isogravitacional (i.e., sentado) (p<0,001). O traçado de WN2 mostrou uma inclinação precoce (fase IIIb) ocorrendo apenas nos decúbitos laterais, além da fase IV ao final. A ascensão lenta da fase IIIb esteve sempre associada a uma significativa mudança no padrão de esvaziamento observado à TIE, onde o esvaziamento preferencial do pulmão dependente dava lugar a um esvaziamento preferencial do pulmão não-dependente. CONCLUSÃO: Em indivíduos sadios e nas situações de baixo esforço expiratório (CVL), a gravidade exerce forte influência na distribuição e variação dos volumes pulmonares ao longo da expiração, sugerindo um significante gradiente vertical de pressões pleurais. O esforço expiratório máximo atenua esta influência da gravidade, sugerindo que outros fatores passam a determinar o fluxo expiratório. / Electrical Impedance Tomography, (EIT) is an imaging method that allows studying changes in regional pulmonary ventilation with high temporal resolution. We studied the influence of body position and expiratory effort on regional lung emptying comparing data from spirometry with the EIT acquired simultaneously. METHOD: Eight volunteers monitored continuously with EIT, performed slow vital capacity (SVC) with single-breath nitrogen washout (SBNW) and forced vital capacity (FVC) maneuvers in sitting position, right (RLD) and left lateral decubitus (LLD). In all three positions we compared the impedance change (Z) with spirometry absolute volumes and analyzed the regional volume variation of right and left lungs in each position and every 10% step of total expiration with EIT; this data was compared with SBNW analysis. RESULTS: In spirometry and EIT, there was a reduction in the total volume expired in FVC and SVC in lateral recumbency when compared to the sitting position (P = 0,001). In the analysis of the SVC with EIT we noticed a greater flow in the dependent lungs (from 2 to 10 times higher) on both lateral decubitus, with reversal of this pattern in approximately half of the expired vital capacity. On FVC the Z was similar between the lungs during the entire expiration, regardless of decubitus, and similar to the situation isogravitacional (ie, sitting) (p<0,001). The SBNW curves showed an early inclination (phase IIIb) occurring only in the lateral decubitus, besides the final rise of phase IV. The slow rise of phase IIIb was always associated with a significant change in the emptying pattern observed with the EIT, when the preferential emptying of the dependent lung gave place to preferential emptying in the non-dependent lung. CONCLUSION: In healthy subjects and in situations of low effort (SVC), gravity exerts strong influence on the distribution and variation of lung volume during the expiration, suggesting a significant vertical gradient of pleural pressure. The maximum expiratory effort mitigates this gravitational influence, suggesting that other factors may determine the expiratory flow

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 162-176).

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2018-04-02T13:00:57Z No. of bitstreams: 1 PDF - Mell de Luiz Vânia.pdf: 19273325 bytes, checksum: 0e14c0e04949169910d80f61f7800064 (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2018-04-10T15:10:48Z (GMT) No. of bitstreams: 1 PDF - Mell de Luiz Vânia.pdf: 19273325 bytes, checksum: 0e14c0e04949169910d80f61f7800064 (MD5) / Made available in DSpace on 2018-04-10T15:10:48Z (GMT). No. of bitstreams: 1 PDF - Mell de Luiz Vânia.pdf: 19273325 bytes, checksum: 0e14c0e04949169910d80f61f7800064 (MD5) Previous issue date: 2016-05-31 / Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq / Introduction: Metabolic syndrome (MS) is a multifactorial disease that involves the presence of changes, such as abdominal obesity, high blood pressure (HBP), dyslipidemia and impaired fasting glucose 2. Highly prevalent in the population, there has been increasingly e arly, affecting children and adolescents. Recently it shows its relation to the decline in pulmonary function (PF) in adults, however, this relationship has not yet been investigated in Brazilian adolescents. Objective: To investigate the relationship between lung function and the presence of metabolic syndrome in adolescents. Methods: Cross-sectional study involving 525 adolescents (15-19 years) from public high schools in the city of Campina Grande, Paraíba. Data collection lasted from September 2012 to June 2013, from the application form to obtain the social and demographic data and lifestyle (sedentary lifestyle, physical activity and smoking); anthropometry (weight, height and waist circumference); blood pressure measurement; blood collection (fasting glucose, HDL-cholesterol and triglycerides); and spirometry. Data were double entered and submitted to validation in the subprogram Validate Epi Info 5.4.3. Analyses were performed using the Statistical Package for Social Sciences (SPSS, version 22) and R (2016). Results: The sample of 525 adolescents with a mean age of 16.8 (± 1.0) years was mostly made up of girls (66.5%), non-white (79.6%) and belonging to economic classes C, D and E (68.6%). There was a high prevalence of physically inactive (59.4%) and sedentary (78.4%), and most had normal values for blood pressure (BP) (85.1%), waist circumference (WC) (96.8%), HDL cholesterol (52.8%) and triglycerides (82.9%). There was also that 22.5% had altered nutritional status, 4.2% had metabolic syndrome ( MS) and 21.7% showed impaired pulmonary function (PF). Being male worked as a protective factor for physical activity, on the other hand, it was a risk factor for change BP, HDL cholesterol and forced expiratory volume in 1 second (FEV1). In simple regression found a statistically significant relationship between FEV1, WC and TG, however, after multiple regression and residual analysis only the WC remained in the model with significant (p <0.05). For the Forced Vital Capacity (FVC) after the analysis of the Stepway type, there was relationship with SBP and DBP. As for the Tiffeneau Index, WC was associated in isolation and in all variables. Conclusions: There was no association between FP and SM globally, however, it was found association between its components, proving that metabolic abnormalities are associated with lung disorders. Waist circumference increases was shown as the main factor for the decline in FP adolescents. / Introdução: a síndrome metabólica (SM) é uma doença multifatorial que envolve a presença de alterações, como obesidade abdominal, hipertensão arterial sistêmica (HAS), dislipidemias e glicemia de jejum alterada. Altamente prevalente na população, tem surgido cada vez mais precocemente, afetando crianças e adolescentes. Recentemente se aponta sua relação com o declínio da função pulmonar (FP) em adultos, porém, tal relação ainda não foi investigada na população adolescente brasileira. Objetivo: verificar a relação entre a função pulmonar e a presença de síndrome metabólica em adolescentes. Métodos: estudo transversal, realizado com 525 adolescentes (15-19 anos) de escolas públicas do ensino médio do município de Campina Grande, Paraíba. A coleta de dados aconteceu entre setembro de 2012 e junho de 2013, a partir da aplicação de formulário para obtenção dos dados sociodemográficos e de estilo de vida (sedentarismo, atividade física e tabagismo); antropometria (peso, estatura e circunferência abdominal); aferição da pressão arterial; coleta sanguínea (glicemia de jejum, HDL-colesterol e triglicerídeos); e espirometria. Os dados foram duplamente digitados e submetidos à validação no subprograma Validate do Epi Info 5.4.3. As análises foram realizadas no Statistical Package for the Social Sciences (SPSS, versão 22) e no R (2016). Resultados: a amostra de 525 adolescentes com idade média de 16,8 (±1,0) anos foi composta majoritariamente de meninas (66,5%), não brancos (79,6%) e pertencentes às classes econômicas C, D e E (68,6%). Verificou-se uma alta prevalência de fisicamente inativos (59,4%) e de sedentários (78,4%). Viu-se uma prevalência de 14,9% de pressão arterial (PA) alterada, 3,2% de circunferência abdominal (CA) aumentada, 17,1% tiveram alteração de triglicerídeos e quase metade (47,2%) revelaram baixo colesterol HDL (HDL-c). Observou-se, ainda, que 22,5% tinham estado nutricional alterado, 4,2% tinham síndrome metabólica (SM) e 21,7% mostraram alteração na função pulmonar (FP). Ser do sexo masculino funcionou como fator protetor para a prática de atividade física, por outro lado , mostrou-se como risco para alteração da PA, colesterol HDL e Volume Expiratório Forçado no 1º segundo (VEF1). Na regressão simples constatou-se relação estatisticamente significante entre VEF1, CA e TG, porém, após a regressão múltipla e análise de resíduos somente a CA permaneceu no modelo com significância (p<0,05). Para a Capacidade Vital Forçada (CVF), após a análise do tipo stepway, verificou-se relação com a CA, PAS e PAD. Já para o Índice de Tiffeneau, a CA mostrou-se como fator independente. Conclusões: não houve associação entre a FP e SM de maneira global, no entanto, encontrou-se associação entre seus componentes, comprovando que alterações metabólicas associam-se a alterações pulmonares. A circunferência abdominal aumenta se mostrou como o principal fator para o declínio da FP nos adolescentes.

A Tomografia de Impedância Elétrica (TIE) é um método de imagem que permite estudarmos alterações regionais de ventilação pulmonar com alta resolução temporal. Estudamos a influência da posição corporal e do esforço expiratório no esvaziamento regional pulmonar comparando dados de espirometria com os da TIE adquiridos simultaneamente. MÉTODOS: Oito voluntários monitorados continuamente com TIE, realizaram manobras de capacidade vital lenta (CVL) com washout de nitrogênio (WN2) e capacidade vital forçada (CVF) nas posições sentado, decúbito lateral direito (DLD) e esquerdo (DLE). Em todas as posições, comparamos a variação global de impedância (Z) com os volumes da espirometria. Analisamos também as variações regionais de volume do pulmão direito e esquerdo, em cada posição, e a cada 10% da expiração total através da TIE; estes dados foram comparados com análise do WN2. RESULTADOS: Na espirometria e na TIE, houve uma redução no volume total expirado na CVF e na CVL dos decúbitos laterais quando comparados à posição sentada (P = 0,001). Na análise da CVL através da TIE, observamos um fluxo maior no pulmão dependente (de 2 a 10 vezes maior), em ambos os decúbitos laterais, com inversão deste padrão aproximadamente na metade da capacidade vital. Já na CVF o Z foi semelhante entre os pulmões ao longo da expiração, independente do decúbito, semelhante à situação isogravitacional (i.e., sentado) (p<0,001). O traçado de WN2 mostrou uma inclinação precoce (fase IIIb) ocorrendo apenas nos decúbitos laterais, além da fase IV ao final. A ascensão lenta da fase IIIb esteve sempre associada a uma significativa mudança no padrão de esvaziamento observado à TIE, onde o esvaziamento preferencial do pulmão dependente dava lugar a um esvaziamento preferencial do pulmão não-dependente. CONCLUSÃO: Em indivíduos sadios e nas situações de baixo esforço expiratório (CVL), a gravidade exerce forte influência na distribuição e variação dos volumes pulmonares ao longo da expiração, sugerindo um significante gradiente vertical de pressões pleurais. O esforço expiratório máximo atenua esta influência da gravidade, sugerindo que outros fatores passam a determinar o fluxo expiratório. / Electrical Impedance Tomography, (EIT) is an imaging method that allows studying changes in regional pulmonary ventilation with high temporal resolution. We studied the influence of body position and expiratory effort on regional lung emptying comparing data from spirometry with the EIT acquired simultaneously. METHOD: Eight volunteers monitored continuously with EIT, performed slow vital capacity (SVC) with single-breath nitrogen washout (SBNW) and forced vital capacity (FVC) maneuvers in sitting position, right (RLD) and left lateral decubitus (LLD). In all three positions we compared the impedance change (Z) with spirometry absolute volumes and analyzed the regional volume variation of right and left lungs in each position and every 10% step of total expiration with EIT; this data was compared with SBNW analysis. RESULTS: In spirometry and EIT, there was a reduction in the total volume expired in FVC and SVC in lateral recumbency when compared to the sitting position (P = 0,001). In the analysis of the SVC with EIT we noticed a greater flow in the dependent lungs (from 2 to 10 times higher) on both lateral decubitus, with reversal of this pattern in approximately half of the expired vital capacity. On FVC the Z was similar between the lungs during the entire expiration, regardless of decubitus, and similar to the situation isogravitacional (ie, sitting) (p<0,001). The SBNW curves showed an early inclination (phase IIIb) occurring only in the lateral decubitus, besides the final rise of phase IV. The slow rise of phase IIIb was always associated with a significant change in the emptying pattern observed with the EIT, when the preferential emptying of the dependent lung gave place to preferential emptying in the non-dependent lung. CONCLUSION: In healthy subjects and in situations of low effort (SVC), gravity exerts strong influence on the distribution and variation of lung volume during the expiration, suggesting a significant vertical gradient of pleural pressure. The maximum expiratory effort mitigates this gravitational influence, suggesting that other factors may determine the expiratory flow