Efectos de la menopausia temprana en la función pulmonar: revisión integrativa / Effects of early menopause on lung function: an integrative review

La menopausia provoca cambios hormonales y alteraciones sistémicas. La menopausia normal sucede entre los 45-55 años y la menopausia temprana (MT) se desarrolla antes de los 45 años. Revisar la evidencia que señala posibles asociaciones entre la MT y la función pulmonar, analizando específicamente aquellos componentes que se encuentran alterados. Se eligieron estudios transversales y revisiones sistemáticas, en inglés, portugués y español. La búsqueda se realizó de marzo a noviembre de2022, en PubMed y Scopus, aemás de búsquedas manuales. La calidad metodológica fue analizada utilizando la escala Strengthening the Reporting of Observational Studies in Epidemiology para los estudios observacionales, y el Ameasurement Tool to Assess Systematic Review para las revisiones. Se encontraron 698 estudios, 12 seleccionados para calificación metodológica, cinco excluidos. Al final del análisis metodológico, se obtuvieron seis estudios transversales y una revisión sistemática, llevados a cabo en Reino Unido, Europa y Asia. Hay una tendencia para asociación de la MT a un patrón ventilatorio restrictivo. Sin embargo la evidencia sigue siendo escasa y se sugiere la realización de nuevos estudios.

Menopause causes hormonal changes and systemic alterations. Normal menopause is when this event occurs between the ages of 45 and 55, and early menopause (EM) when it develops earlier than 45 years. To review the evidence that indicates possible associations between EM and lung function, specifically analyzing those components that are altered. Cross-sectional and systematic reviews studies, published from 2000-2022, in English, Portuguese and Spanish were selected from March to November 2022, in PubMed and Scopus and through manual searches. Methodological quality was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology scale for observational studies, and the Measurement Tool to Assess Systematic Review for reviews. 698 studies were found, 12 were selected for methodological quality review and 5 were excluded. At the end of methodological analysis, 6 cross-sectional studies and 1 systematic review were obtained, carried out in United Kingdom, Europe and Asia. There is a tendency for EM to be associated with restrictive ventilatory pattern. However, the evidence is scarce and further studies are suggested.

Morphological characteristics and pulmonary function of naval saboteurs and ground special forces of the armed forces of Montenegro / Características morfológicas y función pulmonar de saboteadores navales y fuerzas especiales terrestres de las fuerzas armadas de Montenegro

SUMMARY: The results of numerous medical and kinesiological studies indicate the existence of differences in pulmonary function in relation to age, body height, and the relationship between certain parameters of body composition. The aim of this study was to determine the state of morphological characteristics and pulmonary function of naval saboteurs and ground Special Forces of the Armed Forces of Montenegro. The sample of participants included 30 naval saboteurs aged 30.3±6 years and 30 members of the ground special forces aged 25.6±5 years. The sample of measuring instruments included 4 indicators each for the evaluation of longitudinal dimensionality, transversal dimensionality, mass and body volume, subcutaneous fat, body composition, and pulmonary function. The central and dispersion parameters of the variables were calculated. The specificities of body composition of the naval saboteurs and members of the ground Special Forces of the AF of Montenegro were determined, while the parameters of lung volume and capacity and the parameters of airway flow indicated an excellent state of their respiratory function. Furthermore, it was determined that the studied members of the armed forces had no individual health risks in the sense of the onset of obesity or obstructive ventilatory defects. The results obtained indicate the need for further studies which would predominantly focus on the impact of individual morphological measurements and parameters of body composition on pulmonary function. This would provide important data both for the armed forces in the sense of improving the training system and the realization of specific tasks, as well as for kinesiology as a science from the aspect of determining certain regularities in the functioning of the human body in specific living and working conditions in the armed forces.

Los resultados de numerosos estudios médicos y kinesiológicos indican la existencia de diferencias en la función pulmonar en relación con la edad, la altura corporal y la relación entre determinados parámetros de la composición corporal. El objetivo de este estudio fue determinar el estado de las características morfológicas y la función pulmonar de los saboteadores navales y de las Fuerzas Especiales terrestres de las Fuerzas Armadas de Montenegro. La muestra de participantes incluyó a 30 saboteadores navales de 30,3±6 años de edad y 30 miembros de las fuerzas especiales terrestres de 25,6±5 años. La muestra de instrumentos de medición incluyó 4 indicadores cada uno para la evaluación de dimensionalidad longitudinal, dimensionalidad transversal, masa y volumen corporal, grasa subcutánea, composición corporal y función pulmonar. Se calcularon los parámetros centrales y de dispersión de las variables. Se determinaron las especificidades de la composición corporal de los saboteadores navales y miembros de las Fuerzas Especiales terrestres de la FA de Montenegro, mientras que los parámetros de volumen y capacidad pulmonar y los parámetros de flujo de las vías respiratorias indicaron un excelente estado de su función respiratoria. Además, se determinó que los miembros de las fuerzas armadas estudiados no tenían riesgos individuales de salud en el sentido de la obesidad o defectos ventilatorios obstructivos. Los resultados obtenidos indican la necesidad de más estudios que se centren predominantemente en el impacto de las medidas morfológicas individuales y los parámetros de composición corporal en la función pulmonar. Esto proporcionaría datos importantes tanto para las fuerzas armadas en el sentido de mejorar el sistema de entrenamiento y la realización de tareas específicas, como para la kinesiología como ciencia desde el aspecto de determinar ciertas regularidades en el funcionamiento del cuerpo humano en situaciones específicas de vida. y condiciones de trabajo en las fuerzas armadas.

Fisiología respiratoria: fisiología del surfactante pulmonar / Physiology of pulmonary surfactant

El proceso de respiración y el intercambio gaseoso requiere la interacción de variadas fuerzas en los distintos tejidos y órganos involucrados. La tensión superficial a nivel alveolar provocaría colapso de dichas estructuras de no ser por las características del surfactante que lo recubre. Revisaremos en este articulo la fisiología involucrada en su estructura física, producción y efectos pulmonares.

The process of breathing and gas exchange requires the interaction of various forces in the different tissues and organs involved. The surface tension at the alveolus would cause collapse of these structures without of the surfactant that covers it. We will review in this article the physiology involved in its physical structure, production, and pulmonary effects.

Development of an Active Mechanical Lung for Simulating Human Pulmonary Ventilation / 中国医疗器械杂志

At present, the passive simulated lung including the splint lung is an important device for hospitals and manufacturers in testing the functions of a respirator. However, the human respiration simulated by this passive simulated lung is quite different from the actual respiration. And it is not able to simulate the spontaneous breathing. Therefore, including" the device simulating respiratory muscle work "," the simulated thorax" and" the simulated airway", an active mechanical lung to simulate human pulmonary ventilation was designed:3D printed human respiratory tract was developed and connected the left and right air bags at the end of the respiratory tract to simulate the left and right lungs of the human body. By controlling a motor running to drive the crank and rod to move a piston back and forth, and to deliver an alternating pressure in the simulated pleural, and so as to generate an active respiratory airflow in airway. The experimental respiratory airflow and pressure from the active mechanical lung developed in this study are consistent with the target airflow and pressure which collected from the normal adult. The developed active mechanical lung function will be conducive to improve the quality of the respirator.

Fisiología respiratoria: el pulmón al momento de nacer / Respiratory Physiology - the lung at the moment of birth

La adaptación fisiológica de los recién nacidos de la vida intrauterina a la extrauterina incluye cambios fisiológicos complejos. Para que se complete con éxito la transición fetal a neonatal, los recién nacidos deben lograr el aclaramiento de líquido pulmonar, la generación de CRF e inicio de la respiración, para permitir el intercambio de gases y la oxigenación de los tejidos. En este artículo se describen estos mecanismos, algunas bases del desarrollo pulmonar y de la circulación fetal; y las medidas que se requieren para asistir al recién nacido cuando no logran completar esta transición espontáneamente, lo que ocurre en el 5 al 10 % de los casos.

The physiological adaptation of newborns from intrauterine to extrauterine life includes complex physiological changes. For the fetal to neonatal transition to be successfully completed, neonates must achieve lung fluid clearance, FRC generation, and initiation of respiration to allow gas exchange and tissue oxygenation. This article describes these mechanisms, some bases of lung development and fetal circulation; and the measures required to assist the newborn, when they fail to complete this transition spontaneously, which occurs in the 5 to 10% of cases.

Effects on extravascular lung water of lung protective ventilation strategy applied on piglets with acute respiratory distress syndrome induced by paraquat / 中华劳动卫生职业病杂志

Objective: To study the effects on extravascular lung water of lung protective ventilation strategy applying on piglets with acute respiratory distress syndrome (ARDS) induced by paraquat (PQ) under pulse indicating continuous cardiac output (PiCCO) monitoring. Methods: The piglets models with ARDS induced by PQ were established in June 2020 and all of them were received mechanical ventilation and divided into three groups according to tidal volume (V(T)) : small V(T) group (6 ml/kg) , middle V(T) group (10 ml/kg) and large V(T) group (15 ml/kg) , there were 5 piglets in each group. The positive end expiratory pressure (PEEP) were all setup on 10 cmH(2)O. The indexes such as arterial blood gas analysis, oxygenation index (OI) , extravascular lung water index (ELWI) and pulmonary vascular permeability index (PVPI) were monitored at time of before the model was established (baseline) , time of the model was established (t(0)) and 2 h (t(2)) , 4 h (t(4)) , 6 h (t(6)) after mechanical ventilation. Lung tissue were punctured at time of baseline, t(0) and t(6) to be stained by Hematoxylin-eosin (HE) staining and pulmonary pathology were observed under light microscopy. Results: The heart rate (HR) , mean arterial pressure (MAP) and partial pressure of carbon dioxide (PaCO(2)) of all groups were higher than the base value while the pH values, partial pressure of oxygen (PaO(2)) and OI were lower than the base value when the models were established (P<0.05) . After mechanical ventilation, the HR and MAP values of all groups at t(2), t(4) and t(6) were lower than t(0) while the PaCO(2) of t(4) and t(6) were all higher than t(0), the differences were statistically significant (P<0.05) . The PaO(2) and OI of all groups showed a trend of rising at first and then decreasing after mechanical ventilation. The MAP, PaO(2), PaCO(2) and OI of the middle V(T) group and large V(T) group were apparently lower than that of the small V(T) group at t(2), t(4) and t(6) (P<0.05) . The ELWI and PVPI at t(0) of all groups were higher than that of baseline (P<0.05) . The ELWI of the small V(T) group at t(6) were lower than t(0) of the same group and t(6) of the middle V(T) group and large V(T) group (P<0.05) . HE staining showed congestion and edema of alveolar tissue, swelling of capillaries, exudation of red blood cells and widening of alveolar septum in piglets after successful modeling. And further widening of alveolar septum and rupture of alveolar septum could be seen in the lung tissues of each group at t(6), and the injury was the slightest in the small V(T) group. Conclusion: The lung protective ventilation strategy can alleviate the extravascular lung water and ARDS induced by PQ and improve oxygenation.

Transcriptome analysis in fetal lungs of SRC1/SRC2 double-knockout mice / 生理学报

Steroid receptor coactivators (SRCs) significantly increase the transcriptional activity of various steroid hormone receptors, and play an important regulatory role in a variety of physiological functions such as food intake, sleep, stress response and reproduction. Previous studies have found that pregnant mice carrying fetuses with SRC1/2 double-knockout (dKO) manifested delayed labor, partly due to the hypoplasia of fetal lungs and the decreased secretion of pulmonary surfactant protein-A (SP-A) and platelet activating factor (PAF). However, there is still a lack of systematic analysis of the changes in gene expression at the whole transcriptome level in the fetal lungs of SRC1/2 dKO mice. In this study, the SRC1KO, SRC2KO, SRC1/2 dKO and wild-type (WT) mouse fetal lung samples were collected at 18.5 days post coitus. The Illumina platform was employed for transcriptome mRNA sequencing, and then the differentially expressed genes (DEGs) were annotated and analyzed by GO and KEGG analysis. The results showed that the proportion of quality score of the sequencing data above Q30 in all samples was more than 92% and passed the quality control. Compared with WT fetal lungs, SRC1KO and SRC2KO fetal lungs had 61 and 32 DEGs, respectively; SRC1/2 dKO fetal lungs had 480, 11 and 901 DEGs compared with WT, SRC1KO and SRC2KO fetal lungs, respectively. Among these genes, Aspg, Crispld2, Eln, Ntsr2, Slc10a6 and Vgll3 were the unique DEGs of SRC1/2 dKO fetal lungs compared with other genotype mice. Real-time PCR and Western blotting verified the reliability of transcriptome sequencing results. The GO analysis of the DEGs between SRC1/2 dKO and WT mouse fetal lungs showed that the DEGs were significantly enriched in the extracellular space, extracellular region, and extracellular matrix in terms of cellular component. In the biological process, they were significantly enriched in the term of development of multiple organs. KEGG pathway analysis showed that the DEGs were mainly enriched in signaling pathways such as the complement system, extracellular matrix-receptor interactions, and protein digestion and absorption. In summary, this study comprehensively revealed the changes of gene expression in the fetal lungs of SRC1/2 dKO mice at the transcriptome level, which provides a new theoretical basis for the study of the developmental regulatory mechanism of the fetal lung during pregnancy, and the fetus-derived signals that affect the initiation of labor.

Efectos de la suplementación con vitamina D en el control del asma en pacientes adultos: una revisión sistemática / Effects of vitamin D supplementation on asthma control in adult patients: a systematic review

INTRODUCCIÓN: El asma es una enfermedad crónica inflamatoria de la vía aérea e inmunomediada en su patogénesis. La vitamina D es un inmunomodulador que regula el perfil secretor de citoquinas, entre otras funciones celulares. Una asociación entre la suficiencia de vitamina D y mejoría en la función pulmonar, control de asma y número de exacerbaciones se ha propuesto en adultos, importante dada la elevada prevalencia de insuficiencia de vitamina D globalmente. OBJETIVO: Conocer los efectos de la suplementación con vitamina D en el control del asma en adultos. MÉTODOS: Se realizó una revisión sistemática de la literatura a través de una búsqueda en la base de datos PubMed y EMBASE. Los desenlaces primarios fueron cambios en VEF1, control sintomático, frecuencia de exacerbaciones, además de eventos adversos y FEM como desenlaces secundarios. La calidad de evidencia de los desenlaces fue evaluada a través del modelo GRADE. RESULTADOS: Siete estudios fueron seleccionados después de remover duplicados y aplicar los criterios de inclusión y exclusión, con calidad de evidencia muy baja aplicando sistema GRADE. DISCUSIÓN: No se encontraron diferencias estadísticamente significativas tras la suplementación con vitamina D en los desenlaces evaluados en general, pero dada la calidad de evidencia muy baja y que no se reportaron efectos adversos serios, es necesario tomar cautelosamente estos resultados. Asímismo no se puede descartar la utilidad de esta terapia como tratamiento auxiliar a los pacientes asmáticos con este déficit vitamínico.

BACKGROUND: Asthma is an airway chronic disease, with an important inflammatory component within its pathogenesis, driven by a dysregulated immune response. Vitamin D is an immunomodulator that regulates cell proliferation, differentiation and cytokine secretion profile. An association between vitamin D sufficiency and improvement in pulmonary function, asthma control and a decrease in exacerbations have been proposed in the adult population, which falls into importance given the high prevalence of vitamin D insufficiency globally. OBJECTIVE: To know vitamin D supplementation effects in asthma control in adults. METHODS: Through a PubMed and EMBASE database search, a systematic review of the literature was conducted. Primary outcomes were: changes in FEV1, symptomatic control, exacerbation frequency and PEF and adverse events as secondary outcomes. Outcome evidence quality assessment was made using the GRADE model. Results: Seven studies were selected after taking out duplicates, applying inclusion and exclusion criteria. In all cases, evidence quality assessed by the GRADE system yielded very low quality. CONCLUSIONS: No statistically significant differences were found after vitamin D supplementation in the overall evaluated outcomes. Nonetheless, a cautious interpretation of studies is mandatory, because evidence quality was very low and no serious adverse events were reported. Hence this treatment usefulness as an ancillary therapy for vitamin D deficient asthmatic patients cannot be dismissed.

Fisiología respiratoria: contribución de la estructura de la vía aérea y el pulmón a la función del aparato respiratorio / Contribution of the airways and lung structure to the respiratory system function

Conocer la estructura del sistema respiratorio es fundamental para comprender cómo realiza sus funciones, desde la principal, el intercambio gaseoso, hasta otras funciones no respiratorias tales como el equilibrio ácido-base, fonación, defensa pulmonar, metabolismo pulmonar y procesamiento de materiales bioactivos. El objetivo de esta revisión es describir los conocimientos actuales de la anatomía del aparato respiratorio y mencionar sus funciones tanto respiratorias como no respiratorias.

Knowing the structure of the respiratory system is essential to understand how it performs its various functions, from the main, gas exchange, to its non-respiratory functions such as acid-base balance, phonation, lung defense, pulmonary metabolism, and the handling of bioactive materials. The main objective of this review is to describe the updated knowledge of the respiratory system's anatomy and to mention its various respiratory and non-respiratory functions.

Fisiología respiratoria mecánica de la respiración / Mechanics breathing

El trabajo respiratorio se ejerce en una estructura cerrada donde se encuentran los pulmones, estos son sometidos a cambios de presiones determinados por la musculatura pulmonar en las diferentes fases del ciclo respiratorio, lo que generará gradientes y permite la entrada y salida de aire. Se suman a ello el calibre de las vías aéreas, el tipo de flujo, las características de las vías aéreas y del surfactante pulmonar, que determinan un menor o mayor trabajo respiratorio según la condición fisiológica.

The work of breathing is exerted in a closed structure where the lungs are located. These are subjected to pressure changes determined by the pulmonary musculature in the different phases of the respiratory cycle, which will generate gradients and allow the entry and exit of air. In addition to the aforesaid, airway calibre, type of flow, airway characteristics and pulmonary surfactant determine less or more work of breathing depending on the physiological condition.

Función pulmonar: medición continua de la saturación del pulso arterial de oxígeno: propuesta para interpretación / Continuous measurement of oxygen arterial pulse saturation: an interpretation proposal

La medición continua de la saturación de pulso arterial de oxígeno (SpO2) es un método no invasivo, confiable y seguro. El consolidado permite obtener valores promedio de SpO2 y frecuencia cardiaca, gráficos y valores acumulados, rangos de valores de SpO2, que permiten definir si existe o no alguna alteración. Los avances tecnológicos han dado paso a la fabricación de equipos con alta exactitud de las mediciones, mediante algoritmos matemáticos que filtran los artefactos debido a movimientos y/o hipoperfusión. La ventaja, es una mayor precisión para determinar estados de hipoxemia en distintas situaciones clínicas. Las principales indicaciones en pediatría son la determinación de hipoxemia y titulación de oxígeno en niños con enfermedades que comprometen el sistema respiratorio, especialmente displasia broncopulmonar. También se usa como screening para apneas obstructivas del sueño en rango moderado a severo en situaciones en que no es posible realizar poligrafía o polisomnografía, dado la facilidad con la que se puede realizar la medición continua de SpO2 en domicilio u hospitalizado. En este artículo se describen características importantes del procedimiento, y se propone un esquema para ordenar su interpretación.

Continuous measurement of arterial oxygen saturation by pulse oximetry (SpO2) is a non-invasive, reliable, and safe method. The consolidated allows obtaining average values of SpO2 and heart rate, graphs and accumulated values, ranges of SpO2 values, which allow defining whether or not there is any alteration. Technological advances have given way to the manufacture of equipment with high measurement accuracy, using mathematical algorithms that filter artifacts due to movements and/or hypoperfusion. The main indications are the diagnosis of hypoxemia and titration of oxygen requirements in patients with chronic lung damage and other diseases that compromise the respiratory system. Also, it is used as screening of moderate to severe obstructive apneas when other sleep studies, such as polysomnography or polygraphy, are not available. It can be done at home or hospitalized. This article describes important characteristics of the procedure, and a scheme is proposed to order its interpretation.

Lung function evaluation through computerized tomography and 3D reconstruction of airways: a body mass index pilot study / Evaluación de la función pulmonar mediante tomografía computarizada y reconstrucción 3D de las vías respiratorias: estudio piloto del índice de masa corporal

SUMMARY: Obesity is a worldwide epidemic that has become a risk factor for the development of respiratory problems, meaning it is necessary to generate models that assess lung function in obese patients for proper treatment. The objective of this study was to evaluate a model for analyzing respiratory function according to body composition, by analyzing the structure and function of the airways by computed tomography (CT). Lung function and body fat percentage (BF%) were measured in three male subjects (25 ± 6 years), with different body mass index (BMI; normal, overweight, obese). A third-dimensional (3D) reconstruction of the airways was performed using CT. Trachea, right and left main bronchi and anterior segmental bronchus of the right and left lung were measured. Three measurement points were established for each structure, and the average value of these three points was used for the analysis. An increase in the thickness of the airways wall of the left and right main bronchi and right segmental bronchus was observed as BMI and BF% increased. The same was observed for the percentage of airway wall area (%AWA) and airway resistance in the main and segmental bronchi. The proposed 3D reconstruction model and the three-point analysis simplified image assessment and allowed to observe the problems caused by obesity in lung function.

RESUMEN: La obesidad es una epidemia mundial, la que se ha transformado en un factor de riesgo en el desarrollo problemas respiratorios. Al respecto, generar modelos de evaluación de la función pulmonar en pacientes obesos es relevante para su adecuado tratamiento. El objetivo de este trabajo fue evaluar un modelo de la estructura y función de las vías aéreas (VA) con tomografía computarizada (TC) que permita analizar su compor- tamiento de acuerdo a la composición corporal. A tres sujetos de sexo masculino (25±6 años), de distinto índice de masa corporal (IMC; normal, sobrepeso, obeso), se les midió función pulmonar y porcentaje de grasa corporal (% GC). A través de TC se realizó una reconstrucción en tercera dimensión (3D) de las VA. Se realizaron mediciones de las VA de la tráquea, bronquios principales derecho e izquierdo y bronquio segmentario anterior del pulmón derecho e izquierdo. Para cada estructura se establecieron tres puntos de medición, el valor utilizado para los análisis fue el promedio de estos tres puntos. En los tres participantes se observó un aumento del grosor de la pared de las vías aéreas de los bronquios principal derecho e izquierdo y bronquio segmentario derecho a medida que aumenta el IMC y el % GC. Por otra parte, el porcentaje de área de la pared de las vías aéreas (% APVA) se comportó de la misma manera para ambos bronquios principales y segmentarios. La resistencia de las vías aéreas (RVA), tanto general como específica, aumentó en paralelo con el % APVA en los bronquios principales y segmentarios. A través de un modelo de reconstrucción 3D de la estructura de la VA por TC, evaluando tres puntos, se pudo observar los problemas que trae la obesidad a la función pulmonar simplificando el análisis de imagen.

Ecuaciones de referencia para informe de espirometrías. ¿Será tiempo de adoptar las ecuaciones de la Global Initiative for Lung Function? / Reference equations for spirometry values. Should be time for adopting the Global Lung Function Initiative equations?

Las guías ATS/ERS recomiendan utilizar valores de referencia nacionales para la interpretación de la espirometría. En 2014 se publicaron valores de referencia en población general chilena adulta, que difieren de los de Knudson actualmente en uso. Sin embargo, la mayoría de los laboratorios de función pulmonar siguen utilizando estas últimas ecuaciones. En 2012 se publicaron las ecuaciones multi-étnicas de la Global Lung Function Initiative (GLI) a fin de estandarizar mundialmente la interpretación de los exámenes de función pulmonar Nuestro objetivo fue comparar la concordancia de los informes espirométricos utilizando las ecuaciones más usadas en Chile versus las GLI. Métodos: Se comparó la concordancia en interpretación del patrón espirométrico (normal, obstructivo y restrictivo) y el grado de alteración, entre GLI con Gutiérrez 2014, con Knudson, y con NHANES III según las recomendaciones de la Sociedad Chilena de Enfermedades Respiratorias, a través del coeficiente de concordancia Kappa (K). Se estudiaron 315 sujetos mayores de 40 años (55% mujeres, edad: 59,3 ± 9,2 años), fumadores o ex fumadores, sanos o con EPOC, sometidos a una espirometría con broncodilatador como parte de un reconocimiento respiratorio. Se graficaron las diferencias utilizando el método de Bland-Altman. Resultados: La concordancia para patrón entre GLI con Gutiérrez 2014, con Knudson y con NHANES III fue buena (K = 0,73; 0,71 y 0,77 respectivamente), al igual que para patrón y grado de alteración (K = 0,68; 0,67 y 0,76 respectivamente). Conclusiones: Encontramos una buena concordancia entre las ecuaciones más usadas en Chile y las de GLI, en una muestra que incluyó adultos, fumadores, ex fumadores sanos y enfermos.

ATS/ERS recommend the use of national reference values for the interpretation of spirometry. Reference values were published (2014) in general adult Chilean population, which are different from those of Knudson currently in use. However, most pulmonary function laboratories continue to use these latter equations. Multi-ethnic Global Lung Function Initiative (GLI) equations were published (2012) in order to standardize the interpretation of pulmonary function tests worldwide. Our objective was to evaluate the agreement in the spirometric reports between the most used equations in Chile with those from GLI. Methods: We compared the agreement in the interpretation of the spirometric pattern (normal, obstructive and restrictive) and the degree of alteration between GLI with Gutiérrez 2014, with Knudson and with NHANES III according to recommendations of the Chilean Society of Respiratory Diseases, through the Kappa concordance coefficient (K). The sample correspond to 315 adults over 40 years of age (55% women, 59.3 ± 9.2 years-old), smokers or ex-smokers, healthy or with COPD, who underwent spirometry with a bronchodilator as part of a respiratory check-up. Differences were plotted using the Bland-Altman method. Results: agreement for pattern between GLI with Gutiérrez 2014, with Knudson and with NHANES III was good (K = 0.73, 0.71 and 0.77 respectively) and also was good for the pattern and degree of alteration (K = 0.68, 0.67 and 0.76 respectively). Conclusions: We found a good agreement between the equations most used in Chile and those from the GLI, for a sample that includes subjects with and without lung disease, smokers and ex-smokers.

Pulmonary ventilation function parameters of children aged 5-14 years in Kunming, China: a comparative analysis of measured values versus predicted values based on Zapletal equation / 中国当代儿科杂志

OBJECTIVE@#To study the percentage of the measured values of the main pulmonary ventilation function parameters in their predicted values based on Zapletal equation among healthy children aged 5-14 years in Kunming, China, and to provide a basis for accurate judgment of pulmonary ventilation function in clinical practice.@*METHODS@#A total of 702 healthy children aged 5-14 years (352 boys and 350 girls) from Kunming were enrolled. The Jaeger spirometer was used to measure the nine indices:forced vital capacity (FVC), forced expiratory volume in one second (FEV1), ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC), maximal mid-expiratory flow (MMEF), forced expiratory flow at 25% of forced vital capacity (FEF25), forced expiratory flow at 50% of forced vital capacity (FEF50), forced expiratory flow at 75% of forced vital capacity (FEF75), peak expiratory flow (PEF), and maximal voluntary ventilation (MVV). The values obtained from the Zapletal equation of predicted values provided by the spirometer were used as the predicted values of children, and the percentage of measured values in predicted values was calculated.@*RESULTS@#In the 702 children, the percentages of the measured values of the main pulmonary ventilation function parameters PEF, FVC, FEV1, FEV1/FVC, and MVV in their predicted values fluctuated from 102% to 114%, 94% to 108%, 98% to 113%, 98% to 107%, and 141% to 183% respectively. As for the main airway velocity parameters, the percentages of the measured values of FEF25, FEF50, FEF75, and MMEF in their predicted values fluctuated from 98% to 116%, 85% to 102%, 71% to 98%, and 83% to 100% respectively. The percentages of the measured values of PEF, FVC, FEV1, FEV1/FVC, MVV, FEF25, FEF50, FEF75, and MMEF in their predicted values had the lower limits of normal of 88.2%, 88.4%, 92.0%, 94.4%, 118.5%, 82.9%, 70.0%, 62.1%, and 70.1% respectively.@*CONCLUSIONS@#There are differences between pulmonary ventilation function parameter levels and normal values provided by Zapletal equation in healthy children aged 5-14 years in Kunming. As for the pulmonary ventilation function parameters of PEF, FVC, FEV, FEV1/FVC, MVV, FEF25, FEF50, FEF75, and MMEF in these children, the lower limits of normal of measured values in predicted values may be determined as 88.2%, 88.4%, 92.0%, 94.4%, 118.5%, 82.9%, 70.0%, 62.1%, and 70.1% respectively.

Comparison of the effects of voluntary and involuntary breath stacking techniques on respiratory mechanics and lung function patterns in tracheostomized patients: a randomized crossover clinical trial / Comparação dos efeitos das técnicas breath stacking e air stacking sobre a mecânica respiratória e o padrão ventilatório em pacientes traqueostomizados: ensaio clínico cruzado randomizado

ABSTRACT Objective: To compare the effects of voluntary breath stacking (VBS) and involuntary breath stacking (IBS) techniques on respiratory mechanics, lung function patterns, and inspiratory capacity in tracheostomized patients. Methods: This was a randomized crossover clinical trial involving 20 tracheostomized patients admitted to the ICU and submitted to the VBS and IBS techniques, in random order, with an interval of 5 h between each. Ten cycles of each technique were performed with an interval of 30 s between each cycle. In VBS, patients performed successive inspirations for up to 30 s through a one-way valve, whereas in IBS, successive slow insufflations were performed with a resuscitator bag until the pressure reached 40 cmH2O. Respiratory mechanics, inspiratory capacity, and the lung function pattern were evaluated before and after the interventions. Results: After IBS, there was an increase in static compliance (p = 0.007), which was also higher after IBS than after VBS (p = 0.03). There was no significant difference between the pre-VBS and post-VBS evaluations in terms of static compliance (p = 0.42). Inspiratory capacity was also greater after IBS than after VBS (2,420.7 ± 480.9 mL vs. 1,211.3 ± 562.8 mL; p < 0.001), as was airway pressure (38.3 ± 2.6 cmH2O vs. 25.8 ± 5.5 cmH2O; p < 0.001). There were no changes in resistance or lung function pattern after the application of either technique. Conclusions: In comparison with VBS, IBS promoted greater inspiratory capacity and higher airway pressure, resulting in an increase in static compliance.

RESUMO Objetivo: Comparar os efeitos das técnicas breath stacking (BS) e air stacking (AS) sobre a mecânica respiratória, o padrão ventilatório e a capacidade inspiratória em pacientes traqueostomizados. Métodos: Ensaio clínico cruzado randomizado envolvendo 20 pacientes traqueostomizados internados em UTI e submetidos a ambas as técnicas, com intervalo de 5 h entre si, de acordo com a randomização. Foram realizados dez ciclos de cada técnica com intervalos de 30 segundos entre si. No BS, os pacientes realizaram inspirações sucessivas por até 30 s por meio de uma válvula unidirecional, enquanto no AS foram realizadas insuflações lentas sucessivas através de um ressuscitador manual até que a pressão atingisse 40 cmH2O. Os pacientes foram avaliados quanto a mecânica respiratória, capacidade inspiratória e padrão ventilatório antes e depois da realização das intervenções. Resultados: Com relação à mecânica respiratória no AS, houve aumento da complacência estática na comparação pré- e pós-intervenção (p = 0,007), assim como entre os momentos pós-AS e pós-BS (p = 0,03). Não houve diferença significativa da complacência estática na realização do BS (p = 0,42). A capacidade inspiratória foi maior após o AS que após o BS (2.420,7 ± 480,9 mL vs. 1.211,3 ± 562,8 mL; p < 0,001), bem como em relação à pressão nas vias aéreas (38,3 ± 2,6 cmH2O vs. 25,8 ± 5,5 cmH2O; p < 0,001). Não foram observadas alterações na resistência ou no padrão ventilatório em ambas as técnicas. Conclusões: Na presente amostra, o AS promoveu maior capacidade inspiratória e maior pressão nas vias aéreas que as observadas após o BS, com consequente aumento da complacência estática.

Valoración de ecuaciones derivadas del flujo pulmonar y regurgitación tricuspídea: utilidad en el test de vasoreactividad pulmonar / Valuation of equations derived from Pulmonary Flow and Tricuspid Regurgitation: usefulness in Pulmonary Vasoreactivity Testing

RESUMEN: Antecedentes: La presión media arterial pulmonar (PMAP) es una variable hemodinámica indispensable para el diagnóstico, clasificación y pronóstico de la Hipertensión Pulmonar (HP). Su cuantificación se realiza en forma invasiva por cateterismo cardíaco derecho (CCD) y no invasivamente por ecocardiografía Doppler. Masuyama propuso su medición mediante el gradiente transvalvular pulmonar diastólico derivado de la velocidad máxima inicial de la regurgitación pulmonar (∆RPi2) correspondiendo cercanamente a la medición invasiva. Objetivos: Revalidar 3 métodos ecocardiográficos que estiman la PMAP y valorar la utilidad del método de Chemla en el Test de Reactividad Vascular Pulmonar (TRVP). Métodos: Estudio prospectivo, observacional, doble ciego divido en dos etapas. A) o I) 30 pacientes se realizó ecocardiografía Doppler diagnóstica en nuestro centro. Se midieron regurgitación tricuspídea (RT) y tiempo de aceleración pulmonar (TAP) para derivar las siguientes ecuaciones: 1) 0.61xPSAP+1.95 (Chemla) 2) Gradiente presión media RT (∆PmRT) +PAD (presión-aurícula derecha) (Aduen) y 3) 79-0.45xTAP o 90-0.60xTAP, según sea el valor del TAP. B) o II) 10 pacientes enrolados para realizar el TRVP comparando la medición ecocardiográfica (Chemla) con CCD. Resultados: En la primera parte del estudio se encontró alta correlación entre las 3 ecuaciones: ChemlaAduen, R2=0.91; Chemla-Kitabatake, R2=0.87; Aduen-Kitabatake, R2=0,91. En la segunda parte comparando la PMAP-Chemla y Cateterismo derecho (CD) obtuvimos alta correlación: en tiempo 0, 30 min y recuperación:(R2=0.87, 0.99, 0.98, respectivamente). Ambas partes del estudio mostraron límites de concordancia satisfactoria con valor medio de la diferencia entre los métodos cercano a 1 en el t30 y tR del TRVP. Conclusión: los métodos dependientes de la medición de la RT son efectivos y confiables para estimar la PMAP. El método de Chemla es útil en el TRVP.

ABSTRACTS: Background: Mean Pulmonary arterial pressure (PMAP)is an indispensable hemodynamic variable for the diagnosis, classification and prognosis of Pulmonary Hypertension (PH). Its quantification is performed invasively by cardiac catheterization and non-invasively by Doppler echocardiography. Masuyama proposed its measurement by the transvalvular diastolic pulmonary gradient derived from the initial maximum velocity of pulmonary regurgitation(ΔPRi2) corresponding closely to the invasive measurement. Objectives: to compare 3 known echocardiographic methods to estimate MPAP and demonstrate the usefulness of the Chemla method in the Pulmonary Vascular Reactivity Test (PVRT). Methods: prospective, observational, double-blind study divided into two stages. A) 30 patients underwent diagnostic Doppler echocardiography. Tricuspid regurgitation (TR) and pulmonary acceleration time (PAT) were measured to derive the equations: 1) 0.61xSPAP + 1.95 (Chemla) 2) Gradient mean pressure TR (ΔPmTR) + RAP (right atrium pressure) (Aduen).3) 79-0.45xPAT o 90-0.60xPAT depending on the value of PAT. B) 10 patients enrolled to PVRT comparing the echocardiographic measurement (Chemla) with right catheterization. Results: in the first part of the study a high correlation between the 3 equations was found : ChemlaAduen, R2 = 0.91; Chemla-Kitabatake, R2=0.87; Aduen-Kitabatake, R2=0.91. In the second part comparing the MPAP-Chemla and RHC we obtained a high correlation in time 0, 30 min and recovery: (R2=0.87,0,99,0.98, respectively). Both parts of the study showed satisfactory limits concordance with mean value of the difference between the methods close to 1 in the t30 and tR of the TRVP. Conclusion: the methods dependent on the measurement of the TR are effective and reliable for estimating MPAP. The Chemla method is useful in the PVRT.

Uso del índice de masa corporal y porcentaje de grasa corporal en el análisis de la función pulmonar / Use of the body mass index and body fat percentage in the analysis of pulmonary function

En la actualidad la obesidad es considerada como una pandemia, además de los cambios metabólicos ya sabidos, se producen alteraciones estructurales como las generadas en el sistema ventilatorio. Sin embargo, se ha observado que dependiendo de la forma de categorización de esta condición, puede o no existir alteración sobre este sistema generando así una complicación al momento de la elección de esta herramienta. Por lo tanto el objetivo de esta investigación fue comparar parámetros de la función pulmonar en individuos obesos (O) y normo-peso (Np) según índice de masa corporal (IMC) y porcentaje de grasa corporal (PGC). Se midió la función ventilatoria en 57 participantes, posteriormente estas variables se contrastaron entre los sujetos normo-peso (Np) y obesos (O) según IMC y PGC. Se observó un aumento significativo en el valor de la capacidad inspiratoria (CI) de O versus Np y del volumen de reserva espiratoria (VRE) y capacidad residual funcional (CRF) de Np en relación a O, tanto para la división por IMC como por PGC, en el grupo dividido por IMC las variables de resistencia especifica de las vías aéreas (sRaw) y presión inspiratoria máxima (PImáx) fueron significativamente mayor en los participantes O, asimismo, la conductancia específica de las vías aéreas (sGaw) fue significativamente mayor en sujetos Np. En conclusión, el IMC mostró mayor versatilidad como predictor de la función ventilatoria, sin embargo, se necesitan mayores estudios de los efectos mecánicos de este indicador y del PGC sobre las vías aéreas.

Currently, obesity is considered a pandemic, in addition to the known metabolic changes, structural alterations such as those generated in the ventilatory system occur. However, it has been observed that depending on the form of categorization of this condition, there may or may not be alteration on this system, thus generating a complication when choosing this tool. Therefore, the objective of this study was to compare parameters of lung function in obese individuals and normo-weight according to body mass index (BMI) and body fat percentage (BFP). The ventilatory function was measured in 57 participants, later these variables were contrasted between the subjects normal weight (Nw) and obese (O) according to BMI and BFP. A significant increase in the inspiratory capacity (IC) value of O versus Nw was observed and of the expiratory reserve volume (ERV) and functional residual capacity (FRC) of Nw in relation to O, both for the division by BMI and by BFP. In the group divided by BMI, the variables of specific resistance of the airways (sRaw) and maximal inspiratory pressure (MIP) were significantly higher in the participants O. In addition, specific airway conductance (sGaw) was significantly higher in subjects Nw. In conclusion, the BMI showed greater versatility as a predictor of ventilatory function, however, more studies are needed on the mechanical effects of this indicator and the BFP on the airways.

Actualización en espirometría y curva flujo / volumen en escolares y adolescentes / School and adolescent spirometry and flow / volume curve update

Spirometry is the most commonly used test to evaluate lung function in children and adults. To obtain good quality results, several requirements must be fulfilled: professional capacity of the technician, the quality of the equipment, the patient's collaboration, the use of appropriate reference standards. The purpose of spirometry is to define types of ventilatory alterations of the central and peripheral airways, to evaluate the response to bronchodilators and to guide the presence of restrictive diseases. The new consensus of national and international experts are described, which have been perfecting several aspects of this test.

La espirometría es el examen más comúnmente utilizado para evaluar la función pulmonar en niños y adultos. Para obtener resultados de buena calidad deben cumplirse varios requisitos, desde la capacidad profesional del técnico, calidad de los equipos, colaboración del paciente y utilización de patrones de referencia adecuados. La espirometría tiene como utilidad definir alteraciones ventilatorias obstructivas de vía aérea central y periférica, evaluar respuesta a broncodilatador y orientar al diagnóstico de enfermedades restrictivas. Se describen los nuevos consensos de expertos nacionales e internacionales, los cuales han ido perfeccionando varios aspectos de este examen.

Effects of manual chest compression on expiratory flow bias during the positive end-expiratory pressure-zero end-expiratory pressure maneuver in patients on mechanical ventilation / Efeitos da compressão torácica manual sobre o flow bias expiratório durante a manobra positive end-expiratory pressure-zero end-expiratory pressure em pacientes sob ventilação mecânica invasiva

ABSTRACT Objective: To investigate the effects of manual chest compression (MCC) on the expiratory flow bias during the positive end-expiratory pressure-zero end-expiratory pressure (PEEP-ZEEP) airway clearance maneuver applied in patients on mechanical ventilation. The flow bias, which influences pulmonary secretion removal, is evaluated by the ratio and difference between the peak expiratory flow (PEF) and the peak inspiratory flow (PIF). Methods: This was a crossover randomized study involving 10 patients. The PEEP-ZEEP maneuver was applied at four time points, one without MCC and the other three with MCC, which were performed by three different respiratory therapists. Respiratory mechanics data were obtained with a specific monitor. Results: The PEEP-ZEEP maneuver without MCC was enough to exceed the threshold that is considered necessary to move secretion toward the glottis (PEF − PIF difference > 33 L/min): a mean PEF − PIF difference of 49.1 ± 9.4 L/min was achieved. The mean PEF/PIF ratio achieved was 3.3 ± 0.7. Using MCC with PEEP-ZEEP increased the mean PEF − PIF difference by 6.7 ± 3.4 L/min. We found a moderate correlation between respiratory therapist hand grip strength and the flow bias generated with MCC. No adverse hemodynamic or respiratory effects were found. Conclusions: The PEEP-ZEEP maneuver, without MCC, resulted in an expiratory flow bias superior to that necessary to facilitate pulmonary secretion removal. Combining MCC with the PEEP-ZEEP maneuver increased the expiratory flow bias, which increases the potential of the maneuver to remove secretions.

RESUMO Objetivo: Avaliar os efeitos da compressão torácica manual (CTM) sobre o flow bias expiratório durante a manobra positive end-expiratory pressure-zero end-expiratory pressure (PEEP-ZEEP) para a remoção de secreção em pacientes sob ventilação mecânica invasiva. O flow bias, que influencia na remoção de secreção pulmonar, foi avaliado pela razão e diferença entre pico de fluxo expiratório (PFE) e pico de fluxo inspiratório (PFI). Métodos: Estudo cruzado e randomizado no qual participaram 10 pacientes. A manobra PEEP-ZEEP foi aplicada em quatro momentos, sendo um sem CTM e os outros três em associação com a CTM, que foram aplicadas por três fisioterapeutas distintos. Um monitor específico foi utilizado para o registro dos dados de mecânica respiratória. Resultados: A manobra PEEP-ZEEP sem a CTM foi suficiente para ultrapassar o limiar do flow bias expiratório (diferença PFE − PFI > 33 l/min), considerado necessário para deslocar a secreção em direção à glote; a média da diferença PFE − PFI encontrada foi de 49,1 ± 9,4 l/min. A média da razão PFE/PFI alcançada foi de 3,3 ± 0,7. A associação da CTM à PEEP-ZEEP aumentou a média da diferença PFE − PFI em 6,7 ± 3,4 l/min. Foi observada correlação moderada entre a força de preensão manual dos fisioterapeutas e o flow bias gerado durante a CTM. Não foram encontradas alterações hemodinâmicas ou respiratórias adversas ao longo do estudo. Conclusões: A manobra PEEP-ZEEP sem a CTM resultou em um flow bias expiratório superior ao considerado efetivo para auxiliar na remoção de secreção pulmonar. A associação com a CTM aumentou o flow bias expiratório, o que aumenta o potencial da manobra para remover secreções.