Hallazgos microscópicos del tejido pulmonar y los músculos respiratorios en la Enfermedad Pulmonar Obstructiva Crónica (EPOC): Microscopic findings of lung tissue and respiratory muscles in Chronic Obstructive Pulmonary Disease (COPD)

Introduction: In chronic obstructive pulmonary disease (COPD), the diaphragm and sternocleidomastoid respiratory muscles (ECOM) work against increased mechanical loads due to limited air flow and changes in chest conformation due to the condition of pulmonary hyperinflation. Objective: To evaluate the histopathological changes present in the lungs and respiratory muscles (diaphragm and ECOM) of the corpses affected by COPD. Materials and methods: This is a blind and descriptive study with analysis of histological images of biopsy. The history of smoking associated with the presence of pulmonary anthracosis, septal thickening and emphysematous bullae included the inclusion criteria of the study. The study was conducted by optical microscopic analysis of histological sheets obtained from 36 corpses with COPD. The histopathological diagnosis was made by a pathologist who did not know the objectives of the study. Results: In the diaphragm, there was the presence of interposed adipose tissue, muscle atrophy, removal of muscle fibers and fibrosis. In ECOM, the elimination of muscle fibers, muscular atrophy, interposed adipose tissue, muscle hypertrophy and thickening of the tendons were also evident. Conclusions: The changes found in the diaphragm and ECOM muscle biopsies of the bodies with COPD were evidenced as a mechanism of compensation and / or dysfunction of the respiratory system due to biomechanical alterations promoted by the disease.Introducción: En la enfermedad pulmonar obstructiva crónica (EPOC), el diafragma y los músculos respiratorios esternocleidomastoideos (ECOM) funcionan contra el aumento de las cargas mecánicas debido a la limitación del flujo de aire y los cambios en la conformación del tórax debido a la condición de hiperinflación pulmonar. Objetivo: Evaluar los cambios histopatológicos presentes en los pulmones y los músculos respiratorios (diafragma y ECOM) de los cadáveres con Diagnostico  de EPOC. El Estudio: Este es un estudio ciego y descriptivo con análisis de imágenes histológicas de biopsia. El historial de tabaquismo asociado con la presencia de antracosis pulmonar, engrosamiento septal y bullas enfisematosas comprendió los criterios de inclusión del estudio. La muestra consistió en biopsias de pulmón, diafragma y ECOM. El estudio se realizó mediante análisis microscópico óptico de lâminas histológicas obtenidas de 36 cadáveres con EPOC. El diagnóstico histopatológico fue realizado por un patólogo que desconocía los objetivos del estudio. Hallazgos: En el diafragma, hubo la presencia de tejido adiposo interpuesto, atrofia muscular, eliminación de las fibras musculares y fibrosis. En el ECOM, también se evidenció la eliminación de las fibras musculares, la atrofia muscular, el tejido adiposo interpuesto, la hipertrofia muscular y el engrosamiento de los tendones. Conclusiones: Los cambios encontrados en las biopsias musculares de diafragma y ECOM de los cadáveres con EPOC se evidenciaron como un mecanismo de compensación y/o disfunción del sistema respiratorio debido a alteraciones biomecánicas promovidas por la enfermedad

Estudio histopatológico comparativo del nervio frénico proveniente de cadáveres con enfermedad pulmonar obstructiva crónica y sin esta condición: Comparative histopathological study of the phrenic nerve from corpses with chronic obstructive pulmonary disease and without this condition

Introduction: Functional changes resulting from the evolution of chronic obstructive pulmonary disease (COPD) are progressive and irreversible, causing increased diaphragm work due to pulmonary hyperinflation and airway obstruction. Phrenic nerves have promoted innervation of the diaphragm and may have been compromised in COPD condition. Objective: To compare the morphology of the phrenic nerves of the cadavers with COPD and without COPD by optical microscopy. Materials and methods: An exploratory descriptive studio conducted on the Death Verification Service in Alagoas. Pulmonary and phrenic nerve biopsies will be bilaterally taken from the cadavers after a necropsy with the diagnosis of COPD. Tissue samples were fixed and processed by conventional histology for hematoxylin-eosin (HE) histological slides. Biopsies are divided into experimental groups, one composed by patients with COPD and the other with patients without COPD (control - CTR). This classification was realized after the histological analysis, when typical halls of COPD were found. Histological slides were analyzed by optical microscopy by a pathologist, who was able to assess the study. Results: According to the inclusion and exclusion criteria of the study, if it includes 38 cadavers in the initial evaluation, of which 31 are included in the COPD group and 7 in the CTR group. In the analysis of the phrenic nerves, 8 cadavers, 25.8%, of the COPD group had histopathological changes: perineural edema (75%, n=6), nervous atrophy (12.5%, n=1) and perineural eosinophilic infiltrate (12.5%, n=1). The CTR group does not present histopathological alterations of the phrenic nerves. Conclusions: Given the hallmarks of the biopsies performed on the phrenic nerves of the corpses with COPD, we can infer that there is a tendency for nerve alteration, with perineural edema, to be the major modification found.Introducción: Los cambios funcionales resultantes de la evolución de la enfermedad pulmonar obstructiva crónica (EPOC) son progresivos e irreversibles, lo que provoca un aumento del trabajo del diafragma debido a la hiperinflación. Los nervios frénicos promueven la inervación del diafragma y pueden verse comprometidos en la condición de EPOC. Objetivo: Comparar la morfología de los nervios frénicos de los cadáveres con y sin EPOC, mediante microscopía óptica. El Estudio: Estudio descriptivo en el que las muestras de los pulmones y los nervios frénicos bilateralmente de los cadáveres con y sin diagnóstico de EPOC. Las muestras de tejido fueron fijadas y procesaron por histología convencional para laminas histológicas teñidas con hematoxilina-eosina. Las muestras fueron compuestas por pacientes con EPOC (EPOC) y sin EPOC (CTR). Esta clasificación se realizó después del análisis histológico. Las láminas histológicas se analizaron mediante microscopía óptica por un patólogo, que fue un evaluador que no conocía datos del estudio. Resultados: De acuerdo con los criterios de inclusión del estudio, se incluyeron 31 cadáveres en el grupo de EPOC y 7 cadáveres en el grupo CTR. En el análisis de los nervios frénicos, 8 cadáveres, es decir, 25.8%, del grupo de EPOC tuvieron cambios histopatológicos: edema perineural (75%, n=6), atrofia nerviosa (12.5%, n=1) e infiltrado eosinofílico perineural (12.5%, n=1). Conclusiones: Los nervios frénicos de los cadáveres con EPOC tienen tendencia a alteraciones histopatológicas, siendo el edema perineural la principal modificación encontrada

Comparação dos níveis de pressão positiva contínua nas vias aéreas através de dois sistemas

OBJETIVO: Comparar a geração de pressão positiva contínua nas vias aéreas através de um sistema artesanal (selo d'água) e um sistema integrado a um ventilador mecânico (Inter 3®). METODOLOGIA: Foi realizado um estudo de experiências controladas através de simulações em laboratório, no qual foram comparados dois sistemas de geração de pressão positiva nas vias aéreas, um deles produzido de forma artesanal (selo d'água), e outro oferecido por um ventilador mecânico neonatal Inter 3® (Intermed - São Paulo). Foram excluídos os registros onde se constatava descalibração do ventilador mecânico ou variação no fluxo de gases da rede (oscilação da esfera do fluxômetro). Os registros foram avaliados quanto à capacidade de produzir as pressões desejadas (3, 5 e 6 cmH2O) quando submetidos a três valores de fluxo (8, 10 e 12 l/min). Para isso, foram aplicados o teste t de Student para uma amostra pareada e o teste não-paramétrico de Mann-Whitney para amostras independentes. RESULTADOS: Verificamos que os sistemas se comportam de maneira diferente para as mesmas condições de fluxo e pressão positiva expiratória final. O comportamento da pressão média na pressão positiva contínua nas vias aéreas (ventilador mecânico) com 3 cmH2O e fluxos de 8, 10 e 12 l/min foi, respectivamente, 2,26±0,41, 2,22±0,37 e 2,04±0,41; com pressão positiva expiratória de 5 cmH2O, encontramos 3,96±0,41, 3,87±0,43 e 3,75±0,52; e com pressão positiva expiratória de 6 cmH2O, os valores registrados foram 4,94±0,40, 4,85±0,41 e 4,72±0,37. Já o comportamento da pressão média na pressão positiva contínua nas vias aéreas (selo d'água) com 3 cmH2O e fluxos de 8, 10 e 12 l/min foi, respectivamente, 4,24±0,24, 4,46±0,26 e 4,72±0,37; com 5 cmH2O, os valores foram 5,97±0,17, 6,28±0,18 e 6,47±0,31; e com 6 cmH2O, registramos 6,85±0,20, 7,17±0,29 e 7,53±0,31. Todos os registros realizados apresentaram significância estatística (p = 0,000). CONCLUSÃO: Através dos nossos registros, foi possível observar que o sistema pressão positiva contínua nas vias aéreas no Inter 3® comportou-se de forma mais estável e linear do que a pressão positiva contínua nas vias aéreas no selo d'água, uma vez que esta apresentou grandes variações pressóricas.OBJECTIVE: To compare the generation of continuous positive airway pressure using a hand-made device (underwater seal) or a ventilator (Inter 3®). METHODOLOGY: Two positive airway pressure generation systems were compared through laboratory simulations. Measurements were not considered if the mechanical ventilator required calibration or in the presence of gas flow variation (flowmeter sphere oscillation). Recordings were assessed in terms of the capacity to produce the desired pressure (3, 5 and 6 cmH2O) when submitted to three different flow values (8, 10 and 12 l/min). For that end, Student's t test for paired samples and the nonparametric Man-Whitney test for independent samples were employed. RESULTS: We verified that the systems behave in different manners under the same conditions of flow and positive end expiratory pressure. For the mechanical ventilator, the mean pressure behavior under continuous positive airway pressure at 3 cmH2O with flows of 8, 10 and 12 l/min were 2.26±0.41, 2.22±0.37, 2.04±0.41, respectively; under positive end-expiratory pressure at 5 cmH2O we found 3.96±0.41, 3.87±0.43 and 3.75±0.52; and under positive end-expiratory pressure at 6 cmH2O the values recorded were 4.94±0.40, 4.85±0.41 and 4.72±0.37. For the underwater seal, the mean pressure behavior under continuous positive airway pressure at 3 cmH2O with flows of 8, 10 and 12 l/min were 4.24±0.24, 4.46±0.26, 4.72±0.37, respectively; at 5 cmH2O the values were 5.97±0.17, 6.28±0.18, 6.47±0.31; and at 6 cmH2O we recorded 6.85±0.20, 7.17±0.29 and 7.53±0.31. All the comparisons were statistically significant (p = 0.000). CONCLUSION: Through our recordings it was possible to observe that the Inter 3® continuous positive airway pressure system was more stable than the underwater seal