Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Spirometry is the most important tool in diagnosing pulmonary disease and is the most frequently performed pulmonary function test. Respiratory disease is also one of the greatest causes for morbidity and mortality on the Hopi Nation, but no specific reference equations exist for this unique population. The purpose of this study was to determine if population reference equations were necessary for these children and, if needed, to create new age and race-specific pulmonary nomograms for Hopi children. Two hundred and ninety-two healthy children, ages 4-13 years, attending Hopi Nation elementary schools in Arizona, were asked to perform spirometry for a full battery of pulmonary volumes and capacities of which the following were analyzed: forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), FEV1 % (FEV1/FVC), FEF25-75% and peak expiratory flow rate (PEFR). Spirometric data from Navajo children living in the same geographical region as the Hopi children were compared as well as spirometric data from common reference values used for other ethnic groups in the USA. Spirometry tests from 165 girls and 127 boys met American Thoracic Society quality control standards. We found that the natural log of height, body mass and age were significant predictors of FEV1, FVC, and FEF25-75% in the gender-specific models and that lung function values all increased with height and age as expected. The predictions using the equations derived for Navajo, Caucasian, Mexican-American, African-American youth were significantly different (P ≤ 0.05) from the predictions derived from the Hopi equations for all of the variables across both genders, with the exceptions of Hopi versus Navajo FEV1/FVC in the males and Hopi versus Caucasians FEF25-75% in the females. Thus it would appear for this population important to have specific formulae to provide more accurate reference values.

Spirometry is the most important tool in diagnosing pulmonary disease and is the most frequently performed pulmonary function test. Since respiratory disease is the single greatest cause for morbidity and mortality on the Navajo Nation, the purpose of this study was to create newage and race-specific pulmonary nomograms for Navajo children. Five hundred fifty-eight healthy children, ages 6-14 years, attending Navajo Nation elementary schools in Arizona, were asked to perform spirometry to develop population-specific and tribe-specific nomograms for forced vitalcapacity (FVC), forced expiratory volume in 1 sec (FEV1), and FEV1 Ratio (FEV1/FVC). Spirometry tests from 284 girls and 274 boys met American Thoracic Society quality control standards. Lung function values, except for FEV1/FVC, all increased with height. The lower limit of the normal range for FEV1/FVC was 80%. The spirometry reference equations from the healthyboys and girls were developed. Height and the natural log of height were significant predictors of FEV1, FVC, and FEF25-75% in the gender-specific models. The resulting population-specific spirometry reference equations should be used when testing Navajo children ages 6-14 years. However, the use of the NHANES III spirometry reference equations for Caucasian children may not result in significant misclassification in clinical settings providing that a maximal effort is given by the Navajo child being tested.

Introduction: Bronchial thermoplasty (B.T.) is a therapeutic bronchoscopic procedure in which controlled thermal energy is applied to the airway wall to decrease smooth muscle mass. Immediate complications of B.T. include acute exacerbation of bronchial asthma, upper and lower respiratory tract infection, hemoptysis, among others. Our study assessed these immediate adverse events and the changes in forced expiratory volume in one second (FEV1%) measured four hours after each procedure from baseline. The study also aimed to examine the number of activations during each cycle of treatment and its correlation to the corresponding change in FEV1% from baseline. Methods: A case-series analysis of 17 patients who underwent B.T. between 2014 and 2019 was done. Demographic, clinical characteristics, including pre and post-BT FEV1% measures, and the number of activations were obtained. Results: Acute exacerbation of asthma was the commonest complication accounting for 33%, 57%, and 75% after BT1, BT2, and BT3, respectively. There was deterioration in FEV1% after each treatment phase, the most significant being in BT3. There was no correlation between the number of heat activations with the change in FEV1% from baseline. Conclusion: The number of activations in B.T. does not correlate with the immediate deterioration in FEV1%, although exacerbation of asthma is the commonest complication post-B.T.

A evolução da Distrofia Muscular de Duchenne (DMD) culmina na morte dos pacientes por problemas respiratórios, que aparentemente estão relacionados com a fraqueza de sua musculatura. O propósito deste estudo foi avaliar o efeito de três exercícios respiratórios de ioga na função respiratória em pacientes com DMD. A escolha dos exercícios foi motivada pelo fato de não se encontrar similares nos procedimentos fisioterápicos atuais no ocidente e por poderem ser praticados sem a necessidade de aparatos ou ajuda externa, facilitando sua execução diária. Os exercícios foram ensinados individualmente no ambulatório do Hospital das Clínicas da Universidade de São Paulo em dias regulares de consultas dos pacientes. As séries, bem como a sua progressão, levaram em consideração as limitações individuais. Foi realizada uma avaliação inicial das condições respiratórias (função pulmonar e pressões respiratórias) em 85 pacientes com idade entre 6 e 14 anos. Estas avaliações foram repetidas a cada 5 meses (em média) ao longo do treinamento. Os dados foram analisados de diferentes maneiras: pacientes que fizeram todas as avaliações ao longo de 10 meses (N=39); ao longo de 20 meses (N=18) e com os resultados dos pacientes que fizeram pelo menos uma avaliação além da inicial ao longo de 10 meses (N=70). Os grupos foram divididos por faixa etária em dois subgrupos (6 a 9 anos e 10 a 14 anos de idade). Constatou-se na análise com N=39 e N=70 que os pacientes mais novos que executaram os exercícios aplicados, apresentaram depois de 10 meses de treinamento, elevação nos valores absolutos e relativos da capacidade vital forçada (CVF), volume expiratório forçado em 1 segundo (VEF1) e pressão expiratória máxima (PEmax) e que os pacientes mais velhos, depois de 10 meses de treinamento, apresentaram melhora nos índices de pressão expiratória máxima (PEmax) em valores absolutos e relativos. Na análise com N=18 observou-se que os pacientes obtiveram melhora nos valores absolutos da função pulmonar (CVF e VEF1) até os 20 meses de treinamento quando comparamos com os valores do início e para a PEmax em valores absolutos, os resultados aumentam até 10 meses de treinamento e depois se mantém estáveis. Observou-se diminuição no declínio dos índices de função pulmonar dos pacientes quando comparados com crianças normais (porcentagem do predito). Constatou-se na análise determinada pela curva dos resultados da PEmax por faixa etária em valores relativos, que após 10 meses de prática dos exercícios de ioga, o declínio de seus valores foi retardado. O grande fator de melhora destes pacientes foi o aumento da força muscular expiratória forçada conseguido especialmente com a prática da técnica denominada kapalabhati. Recomendamos que estes exercícios sejam incorporados à prática clínica dos pacientes com DMD com a intenção de minimizar os danos causados pela perda da capacidade respiratória. / Duchenne Muscular Dystrophy (DMD) has a progression that culminates in the death of the patients for respiratory problems, which are apparently related to the weakness of the respiratory muscles. The objective of this study was to investigate the effects of three respiratory techniques of yoga in the respiratory function of patients with DMD. The selection of the exercises was conducted taking into account that there are no similar ones in the actual western physiotherapeutic procedures, and due to the fact that all of them may be practiced without the need of any apparatus or external help, making their daily practice easy. The exercises were taught individually in the Ambulatory of the General Hospital of the University of São Paulo during the regular appointments of the patients. The series of exercises, as well as their progressions, took into consideration the individual limitations. In order to establish the respiratory conditions (FVC, FEV1, PImax, and PEmax) of the group, an initial evaluation was conducted with 85 patients between 6 and 14 years old. The follow-up evaluations were carried out on an average 5-month interval, during the training period. Data were analyzed in different ways: subjects which had all the evaluations during 10 months of training (N=39); during 20 months of training (N=18) and with the results of patients that had at lest one evaluation besides the initial in the first 10 months (N=70). Furthermore, the total group was divided by age into 2 subgroups: (from 6 to 9 years old, and from 10 to 14 years old). The analysis of the groups with N=39, and N=70 revealed that, after 10 months of training, the younger subjects had increased their absolute and relative values of forced vital capacity (FVC), expiratory forced volume in 1 sec (FEV1), and maximal expiratory pressure (PEmax) , and that the older subjects, after the same period, had their absolute and relative PEmax also increased. In the analysis of the subgroup with N=18, there was an increase in the absolute values for pulmonary function (FVC and FEV1) until 20 months of training, while for PEmax this increase was seen only until 10 months, and afterwards there was a maintenance of its values. There was a reduction in the decline of the pulmonary function indexes of the patients when compared with healthy subjects (percentage of the predicted). The curve results of relative PEmax according to age revealed that after 10 months of practicing the prescribed exercises, the decline of its values was postponed. The greatest improvement in these children was found in the expiratory muscle power, attained through the practice of the technique called kapalabhati. We recommend the inclusion of these exercises to the clinical treatment of the DMD patients with the intention of minimizing the damage caused by the loss of respiratory capacity.

A evolução da Distrofia Muscular de Duchenne (DMD) culmina na morte dos pacientes por problemas respiratórios, que aparentemente estão relacionados com a fraqueza de sua musculatura. O propósito deste estudo foi avaliar o efeito de três exercícios respiratórios de ioga na função respiratória em pacientes com DMD. A escolha dos exercícios foi motivada pelo fato de não se encontrar similares nos procedimentos fisioterápicos atuais no ocidente e por poderem ser praticados sem a necessidade de aparatos ou ajuda externa, facilitando sua execução diária. Os exercícios foram ensinados individualmente no ambulatório do Hospital das Clínicas da Universidade de São Paulo em dias regulares de consultas dos pacientes. As séries, bem como a sua progressão, levaram em consideração as limitações individuais. Foi realizada uma avaliação inicial das condições respiratórias (função pulmonar e pressões respiratórias) em 85 pacientes com idade entre 6 e 14 anos. Estas avaliações foram repetidas a cada 5 meses (em média) ao longo do treinamento. Os dados foram analisados de diferentes maneiras: pacientes que fizeram todas as avaliações ao longo de 10 meses (N=39); ao longo de 20 meses (N=18) e com os resultados dos pacientes que fizeram pelo menos uma avaliação além da inicial ao longo de 10 meses (N=70). Os grupos foram divididos por faixa etária em dois subgrupos (6 a 9 anos e 10 a 14 anos de idade). Constatou-se na análise com N=39 e N=70 que os pacientes mais novos que executaram os exercícios aplicados, apresentaram depois de 10 meses de treinamento, elevação nos valores absolutos e relativos da capacidade vital forçada (CVF), volume expiratório forçado em 1 segundo (VEF1) e pressão expiratória máxima (PEmax) e que os pacientes mais velhos, depois de 10 meses de treinamento, apresentaram melhora nos índices de pressão expiratória máxima (PEmax) em valores absolutos e relativos. Na análise com N=18 observou-se que os pacientes obtiveram melhora nos valores absolutos da função pulmonar (CVF e VEF1) até os 20 meses de treinamento quando comparamos com os valores do início e para a PEmax em valores absolutos, os resultados aumentam até 10 meses de treinamento e depois se mantém estáveis. Observou-se diminuição no declínio dos índices de função pulmonar dos pacientes quando comparados com crianças normais (porcentagem do predito). Constatou-se na análise determinada pela curva dos resultados da PEmax por faixa etária em valores relativos, que após 10 meses de prática dos exercícios de ioga, o declínio de seus valores foi retardado. O grande fator de melhora destes pacientes foi o aumento da força muscular expiratória forçada conseguido especialmente com a prática da técnica denominada kapalabhati. Recomendamos que estes exercícios sejam incorporados à prática clínica dos pacientes com DMD com a intenção de minimizar os danos causados pela perda da capacidade respiratória. / Duchenne Muscular Dystrophy (DMD) has a progression that culminates in the death of the patients for respiratory problems, which are apparently related to the weakness of the respiratory muscles. The objective of this study was to investigate the effects of three respiratory techniques of yoga in the respiratory function of patients with DMD. The selection of the exercises was conducted taking into account that there are no similar ones in the actual western physiotherapeutic procedures, and due to the fact that all of them may be practiced without the need of any apparatus or external help, making their daily practice easy. The exercises were taught individually in the Ambulatory of the General Hospital of the University of São Paulo during the regular appointments of the patients. The series of exercises, as well as their progressions, took into consideration the individual limitations. In order to establish the respiratory conditions (FVC, FEV1, PImax, and PEmax) of the group, an initial evaluation was conducted with 85 patients between 6 and 14 years old. The follow-up evaluations were carried out on an average 5-month interval, during the training period. Data were analyzed in different ways: subjects which had all the evaluations during 10 months of training (N=39); during 20 months of training (N=18) and with the results of patients that had at lest one evaluation besides the initial in the first 10 months (N=70). Furthermore, the total group was divided by age into 2 subgroups: (from 6 to 9 years old, and from 10 to 14 years old). The analysis of the groups with N=39, and N=70 revealed that, after 10 months of training, the younger subjects had increased their absolute and relative values of forced vital capacity (FVC), expiratory forced volume in 1 sec (FEV1), and maximal expiratory pressure (PEmax) , and that the older subjects, after the same period, had their absolute and relative PEmax also increased. In the analysis of the subgroup with N=18, there was an increase in the absolute values for pulmonary function (FVC and FEV1) until 20 months of training, while for PEmax this increase was seen only until 10 months, and afterwards there was a maintenance of its values. There was a reduction in the decline of the pulmonary function indexes of the patients when compared with healthy subjects (percentage of the predicted). The curve results of relative PEmax according to age revealed that after 10 months of practicing the prescribed exercises, the decline of its values was postponed. The greatest improvement in these children was found in the expiratory muscle power, attained through the practice of the technique called kapalabhati. We recommend the inclusion of these exercises to the clinical treatment of the DMD patients with the intention of minimizing the damage caused by the loss of respiratory capacity.

Introduktion: Spirometri är en av de vanligaste undersökningsmetoderna som utförs vid bedömning av lungfunktion. Vid en dynamisk spirometri mäts lungvolymsförändringar över tid vid detektion av obstruktiva lungsjukdom. Syftet med denna studie var att validera en konventionell spirometriutrustning, Jaeger MasterScreen PFT(Carefusion, Hoechburg, Tyskland), med en ny handhållen utrustning, COPD-6 mätare (Vitalograph COPD-6 400, Ennis, Irland), för att undersöka om det fanns statistisk signifikanta skillnader på mätresultatet mellan dessa två utrustningar.  Metod och material: 22 lungfriska testpersoner mellan åldrarna 20–33 år varav 17 kvinnor och 5 män deltog i denna studie som utfördes vid Örebro universitet. De spirometrivariabler som undersöktes för Jaegerutrustningen var den forcerade exspiratoriska volymen under första sekunden (FEV1), den forcerade vitalkapaciteten (FVC) samt hur stor andel av hela lungvolymen som en person kan andas ut på första sekunden (FEV1/FVC). Med COPD-6 mätaren mättes FEV1, den forcerade exspiratoriska volymen under sex sekunder (FEV6), samt kvoten av dessa (FEV1/FEV6). För att undersöka om det förelåg en statistisk signifikant skillnad användes ett parat t-test med signifikansnivån α=0,05. Resultat: Resultatet från denna studie visade att det förelåg en statistik signifikant skillnad mellan Jaeger MasterScreen PFT och COPD-6 mätaren med p <0,05 för samtliga undersökta variabler. Bland-Altmananalysen visade en spridning inom konfidensintervallet hos samtliga variabler. Slutsats: I denna studie påvisades en statisk signifikant skillnad mellan utrustningarna där COPD-6 mätare visade lägre mätresultat än Jaegerutrustningen för variablerna FEV1 samt FEV6 alternative FVC. Dock kan inte resultatet från denna studie vara representativt för en större population då endast ett få observationer gjordes. / Introduction: Spirometry is one of the most common examination methods performed when assessing lung function. In dynamic spirometry, changes in lung volume are measured over time for the detection of obstructive pulmonary disease. The purpose of this study was to validate a conventional spirometry equipment, Jaeger MasterScreen PFT(Carefusion, Hoechburg, Germany), with a new handheld equipment, COPD-6 screener (Vitalograph COPD-6 400, Ennis, Irland), to investigate whether there were statistically significant differences in the measurement result between these two equipments. Method and material: 22 lung-healthy test subjects between the ages of 20–33 years of whom 17 women and 5 men, participated in this study, which was conducted at Örebro University. The spirometry variables examined for Jaeger equipment were the forced expiratory volume during the first second (FEV1), the forced vital capacity (FVC) and the percentage of total lung volume that a person can exhale at the first second (FEV1 / FVC). With the COPD-6 screener FEV1, forced expiratory volume for six seconds (FEV6), and the ratio of these (FEV1 / FEV6) were measured. To investigate whether there was a statistically significant difference, a paired t-test with the significance level α = 0.05 was used. Results: The results from this study showed that there was a statistically significant difference between the Jaeger MasterScreen PFT and the COPD-6 screener with p <0.05 for all variables examined. The Bland-Altman analysis showed a spread within the confidence interval for all variables. Conclusion: In this study, a statically significant difference was demonstrated between the equipments where COPD-6 screener showed lower measurement results than the Jaeger equipments for the variables FEV1 and FEV6 alternative FVC. However, the results from this study cannot be representative of a larger population as only a few observations were made.

<p>Prema literaturnim podacima poslednjih godina velika pažnja je usmerena ka operativnom riziku i mortalitetu koji su postali najvažniji kriterijumi u ocenama rezultata rada hirur&scaron;kih ustanova, ali i svakog hirurga posebno. Zahvaljujući kompleksnom profilu pacijenata koji se podvrgavaju hirur&scaron;kim intervencijama, precizna procena operativnog rizika postaje sve teža. Predikcija ishoda intervencije u najvećoj meri zavisi od preoperativnih faktora rizika. Ipak, neminovno je da i faktori koji su vezani za samu operaciju u određenom stepenu utiču na ishod hirur&scaron;ke intervencije. Shodno tome, dobar model za procenu rizika treba da obuhvati faktore koji će imati najbolju prediktivnu vrednost. Thoracoscore je prvi bodovni sistem razvijen od strane Francuskog udruženja grudnih i vaskularinih hiruga. Zbog nedovoljne primene tokom poslednje decenije i nekonzistentnih rezultata nije do&scaron;lo do &scaron;irokog međunarodnog prihvatanja ovog modela i njegove rutinske upotrebe. Ova činjenica ukazuje na nedostake samog modela i potrebu za rekalibracijom u cilju postizanja bolje saglasnosti između predikcije operativnog rizika i kliničkog stanja bolesnika. Cilj rada je bio da se ustanovi realna vrednost Thoracoscore bodovnog sistema u proceni operativnog rizika i mortaliteta nakon anatomskih i neanatomskih resekcija pluća u na&scaron;im uslovima, i da se utvrdi prediktivna vrednost faktora rizika koji nisu obuhvaćeni Thoracoscore bodovnim sistemom na ishod grudno-hirur&scaron;kih operacija. Istraživanje je sprovedeno po tipu prospektivne kliničke studije i obuhvatilo je 957 bolesnika operisanih na Klinici za grudnu hirurgiju Instituta za plućne bolesti Vojvodine. Izvr&scaron;ene hirur&scaron;ke procedure bile su anatomske resekcije (lobektomija, bilobektomija, pneumonektomija, Sleeve resekcija, segmentektomija) i neanatomske resekcije pluća (Wedge resekcija i druge atipične resekcije). Thoracoscore je izračunat za svakog bolesnika na osnovu devet parametara: godine starosti, pol, ASA skor, dispnea skor, procena op&scaron;teg stanja bolesnika, dijagnostička grupa, hitnost operacije, vrsta operacije i broj komorbiditeta. S obzirom da prediktivna vrednost Thoracoscore bodovnog sistema u proceni operativnog rizika nije bila adekvatna realnom stanju, regresionom analizom je evaluiran značaj tri nova faktora: forsirani ekspiratorni volumen u prvoj sekundi (FEV1), reoperacija i hirur&scaron;ki pristup (torakotomija, video-asistirana torakoskopija &ndash; VATS). Nakon &scaron;to je univarijantnom analizom potvrđeno da su ovi faktori nezavisni prediktori operativnog ishoda, originalni Thoracoscore model je rekalibrisan. Multivarijantnom analizom putem logističke regresije izračunati su novi beta koeficijenti za originalnih devet faktora, kao i za tri nova, te je kreiran lokalni model za procenu operativnog rizika koji je prilagođen na&scaron;oj populaciji. Prosečna starosti bolesnika bila je 62 &plusmn; 7,52 godina. Većinu uzorka (60,7%) činili su pripadnici mu&scaron;kog pola. Najveći broj resekcija činile su lobektomije (61,4%). Malignitet je bio najučestalija indikacija za operaciju (90,3%). Najveći broj bolesnika imao je 1-2 komorbiditeta (64,3%). Prosečna stopa operativnog rizika na osnovu Thoracoscore-a (4,7% ) bila je veća je od stvarnog (2,9%) intrahospitalnog mortalita (p&lt;0,01). Ovaj model je pokazao zadovoljavajuće rezultate jedino u grupi niskog rizika. Predikcija mortaliteta lokalnim modelom za procenu operativnog rizika u grudnoj hirurgiji se, u statističkom smislu, ne razlikuje od stvarnog mortaliteta (p = NS). Thoracoscore ima dobru diskriminativnu moć, ali nezadovoljavajuću kalibrisanost. Shodno tome, Thoracoscore model se može koristiti za stratifikaciju rizika, ali ne i za predikciju mortaliteta. Za razliku, lokalni model je pokazao dobru diskriminaciju i kalibrisanost u na&scaron;im uslovima. Interni model za procenu rizika bi bio od velike koristi u svakodnevnom kliničkom radu, budući da bi oslikavao realno stanje populacije u kojoj je razvijen i vr&scaron;io preciznu predikciju operativnog rizika.</p> / <p>According to the literature data, over the past several years, great attention has been focused on operative risk and mortality which have become the most important criteria in evaluating the results from surgical departments and individual surgeons, as well. Because of complex profiles of patients undergoing surgical interventions, it is becoming more difficult to assess the risk precisely. Prediction of surgical outcomes mostly depends on the preoperative risk factors. However, factors related to the procedure itself effect the surgical outcome to a certain degree. Therefore, a good risk assessment model must contain factors which will have the best predictive value. Thoracoscore is the first scoring system developed by the French Association of Thoracic and Vascular Surgeons. Due to insufficient utilization over the past decade and inconsistent results, this model has not been widely accepted for routine use. This fact indicates that the model lacks certain aspects and needs to be recalibrated in order to achieve better concordance between the predicted operative risk and the clinical state of the patient. The aim of this study was to determine real value of Thoracoscore scoring system for estimation of operative risk and mortality following anatomic and non-anatomic lung resections in our settings, and to determine predictive value of factors not included in Thoracoscore on the outcome of thoracic surgeries. This prospective study included 957 patients who underwent lung resections at the Thoracic surgery clinic of Institute for Lung Diseases of Vojvodina. Performed surgical procedures were anatomic lung resections (lobectomy, bilobectomy, pneumonectomy, Sleeve resection, segmentectomy) and non-anatomic lung resections (Wedge resection and other atypical resections). Thoracoscore was calculated for each patient based on the following nine parameters: age, gender, ASA score, dyspnea score, performance status classification, diagnostic group, urgency of surgery, surgical procedure and number of comorbidities. Because predictive value of Thoracoscore did not correspond to the actual results, regression analysis was used to evaluate the significance of three new risk factors: forced expiratory volume in the first second (FEV1), reoperation, and surgical approach (thoracotomy, video-assisted thoracoscopy &ndash; VATS). After univariate analysis confirmed that these three factors are independent predictors of operative risk, the original Thoracoscore model was recalibrated. With the use of multivariate analysis by logistic regression, new beta coefficients were calculated for the original nine parameters, as well as for the new three, and consequently a local model for surgical risk assessment that is adapted to our population was created. Average age of patients was 62 &plusmn; 7.52 years. Most of the patients were males (60.7%). Lobectomies constituted the largest number (61.4%) of performed surgeries. The most common indications for surgery were malignant causes (90.3%). Most frequently, patients had 1-2 comorbidities (64.3%). Mean operative risk based on Thoracoscore (4.7%) was greater than the actual intrahospital mortality (2.9%) (p&lt;0.01). This model had adequate results only in the low risk group of patients. Predicted mortality by the local model was not statistically different from the actual mortality (p = NS). Thoracoscore had good discriminative ability, but inadequate calibration. Because of this, Thoracoscore model can be used for risk stratification, but not for mortality prediction. On the other hand, local model showed good discrimination and calibration in our population. Therefore, an internal model for risk assessment would be of great use in everyday clinical practice because it would reflect the real state of the population in which it was developed, predicting the risk more precisely.</p>

Introdução: A DPOC caracteriza-se pela limitação ao fluxo aéreo associada à resposta inflamatória anormal dos pulmões a partículas ou gases nocivos. As alterações mecânicas decorrentes da DPOC estão relacionadas com a disfunção mecânica das fibras do diafragma, já observadas nas fases iniciais da doença. Alguns estudos têm demonstrado o elevado potencial da Técnica de Oscilações Forçadas (FOT) na detecção das alterações mecânicas da DPOC. Contudo, tais aplicações da FOT não permitiam a análise em tempo real das alterações do sistema respiratório, bem como da mobilidade toracoabdominal destes indivíduos. Desta forma, os objetivos desta pesquisa foram analisar, em tempo real, as alterações de impedância do sistema respiratório nas distintas fases do ciclo em portadores de DPOC, assim como avaliar a movimentação toracoabdominal destes indivíduos. Metodologia: Trata-se de um estudo observacional controlado, prospectivo onde foram analisados 48 indivíduos, 23 indivíduos controles e 25 portadores de DPOC com grau de obstrução acentuado. Os indivíduos realizaram exames de FOT para análise da impedância do sistema respiratório e mobilidade toracoabdominal, simultaneamente. Posteriormente aos exames da FOT os indivíduos foram submetidos à Espirometria. Resultados: Os resultados demonstraram aumento da impedância do sistema respiratório nos indivíduos com DPOC em comparação ao grupo controle, em nos parâmetros estudados (Zt, Zi, Ze, Zii, Zie, Zrs e Zpp) (p<0,0001). Em relação às distintas fases do ciclo, os indivíduos deste estudo apresentaram impedâncias maiores na fase inspiratória quando comparadas à fase expiratória (p<0,004). Somente 10% dos portadores de DPOC apresentaram assincronia toracoabdominal (&#966; &#8805; 45), sendo que os valores médios não apresentaram diferença estatística quando comparados ao grupo controle. Discussão: A impedância total do sistema respiratório (Zt) aumentada nos portadores de DPOC confirma o aumento da carga mecânica do sistema respiratório destes indivíduos. Essas alterações são coerentes com o processo fisiopatológico, evidenciado pela obstrução ao fluxo aéreo e destruição do parênquima pulmonar. O aumento da impedância na fase inspiratória quando comparada à fase expiratória, sugere um aumento no trabalho resistivo e elástico. Não foram evidenciados sinais de assincronia na mobilidade toracoabdominal na maior parte dos indivíduos, sugerindo que alguns mecanismos adaptativos atuam na tentativa de evitar a fadiga do músculo respiratório. Conclusões: A DPOC resulta no aumento da carga mecânica do sistema respiratório, alterações identificadas pelo aumento da impedância do sistema respiratório, medida pela FOT em tempo real. Este aumento foi mais evidente durante a fase inspiratória. A mobilidade toracoabdominal não se mostrou alterada na maior parte dos indivíduos com DPOC. Estes resultados são consistentes com publicações prévias e fundamentos fisiopatológicos, confirmando o potencial da FOT monofreqüência na avaliação das modificações relacionadas à DPOC. / Introduction: COPD is carachterized by airflow limitation associated abnormal inflammatory response of the lung to noxious particles or gases. The mechanical alterations associated with COPD have been related with dysfunction of the diaphragm, observed since the initial phases of the disease. Several studies have confirmed the high potential of FOT in the assessment of the mechanics modifications related to COPD. However, such studies did not allow a real-time analysis of the changes in the respiratory system, and the thoracoabdominal mobility of these individuals. Thus, the goals of the present study were to analyze, in real-time, the impedance alterations of the respiratory system in different phases of the respiratory cycle of COPD patients. Methodology: This research consists of a controlled observational study where 48 individuals were analyzed, 23 controls and 25 individuals with COPD and severe airway obstruction. Firstly, they performed simultaneous analysis of impedance of the respiratory system and thoracoabdominal motion. In subsequent examinations, these subjects were submitted to spirometry. Results: The results demonstrated an increase of the respiratory system impedance in individuals with COPD compared with the control group in all of the studied parameters (Zt, Zi, Ze, Zii, Zie, &#916;Zrs e Zpp) (p<0.0001). Considering the different phases of the respiratory cycle, higher impedances were observed in the inspiratory phase (p<0.004). Only 10% of individuals with COPD showed thoracoabdominal asynchrony (&#966;&#8805; 45), and the mean values showed no statistical difference when compared to the control group. Discussions: The total impedance of the respiratory system increased in individuals with COPD, which describes the increase of the mechanic load of the respiratory system in these individuals. These alterations are coherent with the physiopathology of COPD, associated with airflow obstruction and lung parenchyma destruction. The increase of the impedance in the inspiratory phase suggests an increase of the resistive and elastic work. There were not signals of thoracoabdominal asynchrony in the major part of the studied individuals, suggesting that some adaptation mechanisms act to compensate respiratory muscle fatigue. Conclusion: The COPD results in the increase of the mechanic load of the respiratory system. These alterations were identified by the increase of the respiratory system impedance, which was more evidence in the inspiratory phase. The thoracoabdominal asynchrony was not usual in individuals with COPD. Those results are consistent with previously published data and physiopathological fundamentals, confirming the potential of monofrequency FOT in the assessment of the modifications related to COPD.