Comparative analysis of pulmonary function in children born preterm and full-term at 6-9 years of age / Análise comparativa da função pulmonar em crianças de 6 a 9 anos de idade nascidas pré-termo e a termo

Abstract Objective: To compare pulmonary function parameters and the prevalence of altered pulmonary function in children born preterm and full-term, using the Global Lung Initiative reference values. Methods: This is a cross-sectional study with 6-9-year-old children submitted to measurement of airway resistance (Rint) and spirometry according to the American Thoracic Society and European Respiratory Society Technical Statement. The inclusion criteria were, among the preterm group: gestational age <37 weeks and birth weight <2000g; among the full-term group: schoolchildren born full-term with birth weight >2500g, recruited at two public schools in São Paulo, Brazil, matched by sex and age with the preterm group. As exclusion criteria, congenital malformations, cognitive deficit, and respiratory problems in the past 15 days were considered. Results: A total of 112 children were included in each group. Preterm children had gestational age of 30.8±2.8 weeks and birth weight of 1349±334g. Among them, 46.6% were boys, 46.4% presented respiratory distress syndrome, 19.6% bronchopulmonary dysplasia, and 65.2% were submitted to mechanical ventilation in the neonatal unit. At study entry, both groups were similar in age and anthropometric parameters. Parameters of pulmonary function (Z scores) in preterm and full-term groups were: Rint (0.13±2.24 vs. -1.02±1.29; p<0.001); forced vital capacity (FVC) (-0.39±1.27 vs. -0.15±1.03; p=0.106), forced expiratory volume in one second (FEV1)/FVC (-0.23±1.22 vs. 0.14±1.11; p=0.003), FEV1 (-0.48±1.29 vs. -0.04±1.08; p=0.071), and forced expiratory flow between 25% and 75% of vital capacity (FEF25-75) (1.16±1.37 vs. 2.08±1.26; p=0.005), respectively. The prevalence values of altered airway resistance (16.1 vs. 1.8%; p<0.001) and spirometry (26.8 vs. 13.4%, p=0.012) were higher in preterm infants than in full-term ones. Conclusions: Preterm children had higher prevalence of altered pulmonary function, higher Z scores of airway resistance, and lower Z scores of FEV1/FVC and FEF25-75 compared with those born full-term.

RESUMO Objetivo: Comparar parâmetros de função pulmonar e a prevalência de função pulmonar alterada em crianças nascidas pré-termo e a termo, utilizando a referência Global Lung Function Initiative. Métodos: Estudo transversal com crianças de 6-9 anos submetidas à medida de resistência de vias aéreas (Rint) segundo o American Thoracic Society and the European Respiratory Society Technical Statement. Como critérios de inclusão, entre o grupo pré-termo, estavam os nascidos com idade gestacional <37 semanas e peso <2000g; e entre o grupo termo, escolares de duas escolas públicas do município de São Paulo, nascidos a termo com peso >2500g, pareados por sexo e idade com o grupo pré-termo. Excluíram-se malformações congênitas, déficit cognitivo e problemas respiratórios havia menos de 15 dias. Resultados: Incluíram-se 112 crianças em cada grupo. Os prematuros (46,4% masculinos) apresentaram idade gestacional de 30,8±2,8 semanas e peso de 1349±334g. Entre eles, 46,4% tiveram síndrome de desconforto respiratório, 19,6% displasia broncopulmonar, e 65,2% receberam ventilação mecânica na unidade neonatal. À inclusão no estudo, os dois grupos apresentaram idade e dados antropométricos semelhantes. Os valores (escores Z) em nascidos pré-termo e a termo foram, respectivamente: Rint (0,13±2,24 vs. -1,02±1,29; p<0,001), capacidade vital forçada (CVF) (-0,39±1,27 vs. -0,15±1,03; p=0,106), volume expiratório forçado no primeiro segundo (VEF1)/CVF (-0,23±1,22 vs. 0,14±1,11; p=0,003), VEF1 (-0,48±1,29 vs. -0,04±1,08; p=0,071) e fluxo expiratório forçado em 25-75% da capacidade vital (FEF25-75) (1,16±1,37 vs. 2,08±1,26; p=0,005). A prevalência de alterações na resistência de vias aéreas (16,1 vs. 1,8%, p<0,001) e na espirometria (26,8 vs. 13,4%, p=0,012) foi maior nos prematuros. Conclusões: As crianças nascidas pré-termo apresentaram maior prevalência de alteração pulmonar, maiores escores Z de resistência de vias aéreas e menores escores Z de VEF1/CVF e FEF25-75 quando comparadas às nascidas a termo.

Capacidad de difusión de monóxido de carbono, pautas para su interpretación / Diffusing capacity for carbon monoxide, guidelines for interpretation

Resumen La capacidad de difusión de monóxido de carbono (DLCO) es, después de la espirometría, la prueba de función pulmonar rutinaria y no invasiva de mayor utilidad clínica. No obstante, hay sustanciales errores de interpretación del significado fisiológico de la DLCO, de sus medidas derivadas y por consiguiente del significado clínico de sus alteraciones. Además de la utilización de diferentes nomenclaturas, otras fuentes de confusión han contribuido a cierta visión negativa de la prueba. Los aspectos técnicos de la prueba de DLCO tienen la ventaja de estar estandarizados. Pero a diferencia de lo que ocurre con otras pruebas de función pulmonar donde disponemos de valores de referencia que permiten determinar la "normalidad o anormalidad" de las mismas, es difícil aplicar esta vía de análisis en el caso de la DLCO. El hecho central en el análisis de la DLCO, el factor de transferencia para el CO (KCO), y el volumen alveolar (VA) es que para una correcta interpretación es necesario tener en cuenta el mecanismo por el cual la patología induce el cambio. Un KCO del 100% puede ser considerado normal en unas circunstancias o patológico bajo otras y, por el momento, el informe automatizado del estudio no puede discriminar. Este artículo describirá los principios de la prueba de DLCO, presentará diferentes modelos de análisis, expondrá ejemplos concretos y ofrecerá pautas para su correcta interpretación. Se considera indispensable efectuar un análisis integrado de la prueba de DLCO en relación con otras pruebas funcionales y con los datos clínicos.

Abstract The diffusing capacity for carbon monoxide (DLCO) is, after spirometry the standard and noninvasive pulmonary function test of greater clinical use. However, there are substantial errors in the interpretation of the physiological significance of the DLCO, its derived measures and, therefore the clinical significance of its alterations. In addition to the use of different nomenclatures, other sources of confusion have contributed to some negative view of the test. The technical aspects of the DLCO test have the advantage of being well standardized. But unlike what happens with other pulmonary function tests where we have reference values which allow us to determine their "normality or abnormality", it is difficult to apply this route of analysis in the case of DLCO. The central fact in the analysis of DLCO, transference factor for CO (KCO), and alveolar volume (VA) is that for a correct interpretation it is necessary to think about the mechanism by which the pathology induces change. A KCO of 100% can be considered normal in some circumstances or pathological in others and, for the moment, the automated study report cannot discriminate. This article will address the principles of the DLCO test; present different models of analysis submit concrete examples and provide guidelines for their correct interpretation. It is considered essential to carry out an integrated analysis of the DLCO test in relation to other functional tests and clinical data.

Comorbilidades y evolución de la función pulmonar de pacientes con atresia esofágica congénita / Comorbidities and course of lung function in patients with congenital esophageal atresia

Objetivo. Describir las características epidemiológicas, el seguimiento hospitalario y la evolución de los pacientes intervenidos por atresia esofágica y su repercusión en la función pulmonar. Población y métodos. Estudio retrospectivo, longitudinal y analítico. Se revisaron las historias clínicas de pacientes con atresia esofágica nacidos entre 1996 y 2017. Se registraron datos perinatales, tipo de atresia, malformaciones asociadas, complicaciones respiratorias y digestivas, y los datos espirométricos durante tres años. Resultados. Se incluyeron 97 pacientes. El tipo de atresia más frecuente fue el III y el síndrome más frecuente, la trisomía 21. El 13,4 % fallecieron en el período neonatal. El 23,8 % de los pacientes estuvo en seguimiento por Neumología y presentó como complicaciones respiratorias exacerbaciones (el 46,4 %), sibilancias o asma (el 36 %), neumonías (el 26,8 %). El reflujo gastroesofágico fue factor de riesgo de sibilancias (OR 5,31; p = 0,002), exacerbaciones (OR 4,00; p = 0,009) y neumonías (OR 3,24; p = 0,02). En la primera espirometría (n = 20), un 65 % presentaba patrón normal; un 30 %, restrictivo, y un 5 %, mixto. En la segunda espirometría (n = 19), un 42,1 % presentaba patrón normal; un 31,6 %, restrictivo; un 15,8 %, obstructivo, y un 10,5 %, mixto. En la tercera espirometría (n = 14), el 50 % presentaba un patrón espirométrico normal; el 21,4 %, restrictivo; el 14,3 %, obstructivo, y un 14,3 %, mixto. Conclusiones. En nuestra muestra de pacientes, una importante proporción presentó comorbilidades respiratorias y digestivas. La función pulmonar empeoró progresivamente.

Objective. To describe the epidemiological characteristics, hospital follow-up, and course of patients who underwent surgery for esophageal atresia and its consequences on lung function. Population and methods. Retrospective, longitudinal, and analytical study. The medical records of patients with esophageal atresia born between 1996 and 2017 were reviewed. Perinatal data, type of atresia, associated malformations, respiratory and gastrointestinal complications, and spirometry data were recorded over 3 years. Results. A total of 97 patients were included. The most common type of atresia was III, and the most frequent syndrome, trisomy 21; 13.4 % of patients died in the neonatal period; 23.8 % were followed up by the Department of Pulmonology, and their respiratory complications included exacerbations (46.4 %), wheezing or asthma (36 %), and pneumonia (26.8 %). Gastroesophageal reflux was a risk factor for wheezing (OR: 5.31; p = 0.002), exacerbations (OR: 4.00; p = 0.009), and pneumonia (OR: 3.24; p = 0.02). In the first spirometry (n = 20), the pattern was normal in 65 %; restrictive in 30 %; and mixed in 5 %. In the second spirometry (n = 19), the pattern was normal in 42.1 %; restrictive in 31.6 %; obstructive in 15.8 %, and mixed in 10.5 %. In the third spirometry (n = 14), the pattern was normal in 50 %; restrictive in 21.4 %; obstructive in 14.3 %, and mixed in 14.3 %.Conclusions. In our sample of patients, a large proportion had respiratory and gastrointestinal comorbidities. Lung function worsened progressively.

Evolución de la función pulmonar en niños con fibrosis quística durante los primeros 3 años de vida / Course of lung function in children with cystic fibrosis in their first 3 years of life

Introducción. La prevención temprana de las complicaciones respiratorias en niños con fibrosis quística determina una mayor sobrevida. La aplicación de pruebas de función pulmonar desde los primeros meses de vida permite detectar el compromiso respiratorio, inclusive en niños asintomáticos. Objetivo. Evaluar la evolución de la función pulmonar en niños con fibrosis quística durante los primeros 3 años de vida e identificar aquellos factores que la comprometen. Población y métodos. Estudio analítico, observacional, retrospectivo. Se incluyeron menores de 36 meses con, al menos, dos estudios funcionales respiratorios. Resultados. Entre 2008 y 2016, se incluyeron 48 pacientes, de los cuales el 85 % fue diagnosticado por pesquisa neonatal. La primera evaluación funcional respiratoria fue a los 5 meses. La mediana de puntaje Z de flujo máximo a nivel de la capacidad residual funcional fue de -0,05 (intervalo intercuartil: de -1,09 a 1,08). La mediana de cambio del puntaje Z del flujo máximo entre las evaluaciones fue de -0,32 (intervalo intercuartil: de -1,11 a 0,25), p = 0,045. Los pacientes con infecciones respiratorias por Staphylococcus aureus, especialmente los resistentes a meticilina, evidenciaron una mayor declinación de la función pulmonar comparados con los no infectados. Ni el sexo ni el tipo de mutación genética se asociaron a la evolución respiratoria. Se evidenció una muy buena recuperación nutricional a lo largo del estudio. Conclusión. Los niños con fibrosis quística presentan una función pulmonar que, progresivamente, desmejora durante los primeros 3 años de vida. Estos hallazgos se asocian a las infecciones respiratorias por Staphylococcus aureus.

Introduction. The early prevention of respiratory complications in children with cystic fibrosis is determining for a longer survival. The implementation of lung function tests in the first months of life allows to detect respiratory involvement, even in asymptomatic children. Objective. To assess the course of lung function in children with cystic fibrosis in their first 3 years of life and identify the factors affecting it. Population and methods. Observational, retrospective, analytical study. Children younger than 36 months with at least 2 lung function tests were included. Results. Between 2008 and 2016, 48 patients were included; 85 % of them had been diagnosed by newborn screening. The first lung function test was done at 5 months old. The median Z-score of maximal flow at functional residual capacity was -0.05 (interquartile range: -1.09 to 1.08). The median change in the maximal flow Z-score between tests was -0.32 (interquartile range: -1.11 to 0.25), p = 0.045. Patients with Staphylococcus aureus respiratory infections, especially methicillin-resistant SA, evidenced a greater deterioration of lung function compared to those without infection. Neither sex nor the type of genetic mutation were associated with the course of lung function. Nutritional recovery throughout the study was really good. Conclusion. Lung function in children with cystic fibrosis worsens progressively during their first 3 years of life. These findings are associated with Staphylococcus aureus respiratory infections.

Valores de referência para a difusão do monóxido de carbono (fator de transferência) em uma amostra brasileira da raça branca / Reference values for the carbon monoxide diffusion (transfer factor) in a brazilian sample of white race

RESUMO Objetivo Derivar valores de referência em adultos brancos para a difusão do monóxido de carbono (DCO) em uma amostra de diferentes locais do Brasil por um mesmo modelo de equipamento (Sensormedics) e comparar os resultados com os derivados pelas equações de Crapo, Miller e Neder, e da proposta pelo Global Lung Initiative (GLI). Métodos Os testes foram realizados de acordo com as normas sugeridas pela ATS/ERS, em 2005, em seis cidades brasileiras, em 120 voluntários adultos de cada sexo, não fumantes, sem anemia referida e sem doenças pulmonares ou cardíacas. Os previstos foram derivados por regressões lineares e as diferenças entre os valores previstos por alguns autores e os observados no estudo atual foram calculadas. Resultados Nos homens, a idade variou de 25 a 88 anos e a estatura, de 156 a 189 cm. Nas mulheres, a idade variou de 21 a 92 anos e a estatura, de 140 a 176 cm. A DCO se correlacionou de maneira significativa positivamente com a estatura e negativamente com a idade. Os valores previstos pelas equações de Crapo, Neder e Miller foram maiores em comparação aos obtidos pelo estudo atual (p<0,01) em ambos os sexos. Nos homens, os valores não diferiram quando comparados aos calculados pelo GLI (p=0,29); nas mulheres, os valores derivados pelo GLI foram levemente maiores: 0,99 mL/min/mmHg (p<0,01). Conclusões Novos valores previstos para a DCO foram derivados em uma amostra de adultos brancos no Brasil. Os valores previstos são semelhantes aos compilados pelas equações GLI e diferem de equações propostas anteriormente.

ABSTRACT Objective To derive reference values from white race adults, for DCO in a sample from different sites in Brazil, through the same equipment model (Sensormedics), and compare the results with the derivatives from Crapo, Miller, Neder equations and from the Global Lung Initiative (GLI) proposal. Methods The tests were performed according to the norms suggested by ATS/ERS in 2005 in six Brazilian cities, with 120 adult volunteers of each gender, non-smokers, without referred anemia and without lung or cardio diseases. The expected values were derived from linear regressions and the differences between the values forecasted by some authors and the ones observed in the current study were calculated. Results Among men, the age varied between 25 and 88 years old, and the height varied between 140 and 176 cm. DCO was correlated significantly and positively with the height and negatively with the age. The values forecasted by Crapo, Neder, and Miller equations were higher in comparison with the ones obtained by the current study (p<0.01) in both genders. Among men, the values did not differ when compared to the ones calculated by GLI (p=0.29); among women, the values derived by GLI were slightly higher: 0.99 ml/min/mmHg (p<0.01). Conclusion new values forecasted for DCO were derived in a sample of white adults in Brazil. The forecasted values are similar to the ones complied by GLI equations and differ from the previously proposed equations.

Correlation among fractional exhaled nitric oxide, child asthma control test, lung function and disease severity in children with asthmatic / 中国医师进修杂志

Objective To investigate the correlation among fractional exhaled nitric oxide (FeNO), child asthma control test(C-ACT) and lung function in asthmatic children and its clinical significance. Methods A total of 108 cases of asthmatic children in the Affiliated Hospital of Qingdao University from June 2016 to September 2018 were recruited. Forty-seven cases (47.44%) were in acute onset, 40 cases(40.37%) were in chronic persistent, and 21 cases (21.19%) were in paracmasis. FeNO, lung function and C-ACT score were measured, and the correlation among them was analyzed. Results The level of FeNO in acute onset patients and chronic persistent patients had no significant difference:(44.18 ± 25.47)×10-9 vs. (46.98 ± 27.50)×10-9, P>0.05, but the level of FeNO in paracmasis patients was lower [(24.43 ± 10.71) × 10-9], compared with that of acute onset patients and chronic persistent patients, there were significant differences (P < 0.01). The scores of C-ACT in three groups had significant difference (P < 0.01), and there were significant differences between any two groups (P <0.01). The levels of forced expiratory peak flow rate measured value as a percentage of predicted value (FEV1%) and forced expiratory volume and forced vital capacity ratio in the first second (FEV1/FVC) in acute onset patients were significantly lower than those in chronic persistent patients and paracmasis patients (P <0.01), and there were no significant differences between chronic persistent patients and paracmasis patients (P＞0.05). Conclusions Compared with lung functions and C-ACT, FeNO is a good biomarker to evaluate the airway inflammation of asthmatic children.

Genes and Pathways Regulating Decline in Lung Function and Airway Remodeling in Asthma

Asthma is a common disorder of the airways characterized by airway inflammation and by decline in lung function and airway remodeling in a subset of asthmatics. Airway remodeling is characterized by structural changes which include airway smooth muscle hypertrophy/hyperplasia, subepithelial fibrosis due to thickening of the reticular basement membrane, mucus metaplasia of the epithelium, and angiogenesis. Epidemiologic studies suggest that both genetic and environmental factors may contribute to decline in lung function and airway remodeling in a subset of asthmatics. Environmental factors include respiratory viral infection-triggered asthma exacerbations, and tobacco smoke. There is also evidence that several asthma candidate genes may contribute to decline in lung function, including ADAM33, PLAUR, VEGF, IL13, CHI3L1, TSLP, GSDMB, TGFB1, POSTN, ESR1 and ARG2. In addition, mediators or cytokines, including cysteinyl leukotrienes, matrix metallopeptidase-9, interleukin-33 and eosinophil expression of transforming growth factor-β, may contribute to airway remodeling in asthma. Although increased airway smooth muscle is associated with reduced lung function (i.e. forced expiratory volume in 1 second) in asthma, there have been few long-term studies to determine how individual pathologic features of airway remodeling contribute to decline in lung function in asthma. Clinical studies with inhibitors of individual gene products, cytokines or mediators are needed in asthmatic patients to identify their individual role in decline in lung function and/or airway remodeling.

Association of Sensitization to Different Aeroallergens With Airway Function and Nasal Patency in Urban Children

PURPOSE: Children with sensitization to aeroallergens have decreased lung function and nasal patency. Our purpose was to determine the association of sensitization to different aeroallergens with airway function and nasal patency. METHODS: Four hundred and eighty-six randomly selected 11 year-old children who lived in Seongnam City were examined. Serum specific immunoglobulin E (IgE) levels against 6 common allergens (Dermatophagoidesfarinae, birch, cat, dog, Japanese hop and Alternaria), impulse oscillometry (IOS) results for the evaluation of airway dysfunction, and acoustic rhinometry for the determination of nasal airway patency were obtained. RESULTS: IOS indicated that children sensitized to Alternaria (n = 38, 7.8%) and dog dander (n = 69, 14.2%) had decreased lung function, based on resistance at 10 Hz (Rrs10; aβ = 0.0072; 95% CI, 0.017, 0.127; P = 0.010) and 1 Hz (Rrs1; aβ = 0.038; 95% CI, 0.001, 0.074; P = 0.042). Children sensitized to D. farinae (n = 281, 57.8%) had decreased post-decongestant nasal volume at 0 to 5 cm (aβ = −0.605; 95% CI, −1.005, −0.205; P = 0.003), but normal IOS results at all measured frequencies (P > 0.05). Increased serum eosinophil level was associated with Rrs1 (P = 0.007) and Rrs2 (P = 0.018) and post-decongestant nasal volume at 0 to 5 cm (aβ = −0.885; 95% CI, −1.331, −0.439; P < 0.001). CONCLUSIONS: Sensitivity to specific aeroallergens, serum eosinophil count and total IgE level had different associations with upper and lower airway dysfunction in urban children.

Effects of obesity on lung volume and capacity in children and adolescents: a systematic review / Efeitos da obesidade sobre os volumes e as capacidades pulmonares em crianças e adolescentes: uma revisão sistemática

Abstract Objective: To assess the effects of obesity on lung volume and capacity in children and adolescents. Data source: This is a systematic review, carried out in Pubmed, Lilacs, Scielo and PEDro databases, using the following Keywords: Plethysmography; Whole Body OR Lung Volume Measurements OR Total Lung Capacity OR Functional Residual Capacity OR Residual Volume AND Obesity. Observational studies or clinical trials that assessed the effects of obesity on lung volume and capacity in children and adolescents (0-18 years) without any other associated disease; in English; Portuguese and Spanish languages were selected. Methodological quality was assessed by the Agency for Healthcare Research and Quality. Data synthesis: Of the 1,030 articles, only four were included in the review. The studies amounted to 548 participants, predominantly males, with sample size ranging from 45 to 327 individuals. 100% of the studies evaluated nutritional status through BMI (z-score) and 50.0% reported the data on abdominal circumference. All demonstrated that obesity causes negative effects on lung volume and capacity, causing a reduction mainly in functional residual capacity in 75.0% of the studies; in the expiratory reserve volume in 50.0% and in the residual volume in 25.0%. The methodological quality ranged from moderate to high, with 75.0% of the studies classified as having high methodological quality. Conclusions: Obesity causes deleterious effects on lung volume and capacity in children and adolescents, mainly by reducing functional residual capacity, expiratory reserve volume and residual volume.

Resumo Objetivo: Avaliar os efeitos da obesidade sobre os volumes e as capacidades pulmonares em crianças e adolescentes. Fontes de dados: Trata-se de uma revisão sistemática, através das bases de dados Pubmed, Lilacs, SciELO e PEDro, por meio das seguintes palavras-chave: Plethysmography, Whole Body OR Lung Volume Measurements OR Total Lung Capacity OR Functional Residual Capacity OR Residual Volume AND Obesity. Foram selecionados estudos observacionais ou ensaios clínicos que avaliaram os efeitos da obesidade sobre os volumes e as capacidades pulmonares em crianças e adolescentes (0 a 18 anos), sem qualquer outra doença associada, nos idiomas inglês, português e espanhol. A qualidade metodológica foi avaliada através da Agency for Healthcare Research and Quality. Síntese dos dados: Dos 1.030 artigos, apenas quatro foram incluídos nesta revisão. Os estudos totalizaram 548 participantes, com predomínio do sexo masculino e tamanho amostral entre 45 e 327 indivíduos; 100% dos estudos avaliaram o estado nutricional através do IMC (escore-z) e 50% informaram os dados da circunferência abdominal. Todos demonstraram que a obesidade causa efeitos negativos sobre os volumes e as capacidades pulmonares, causa redução, principalmente, da capacidade residual funcional em 75% dos estudos, do volume de reserva expiratório em 50% e do volume residual em 25%. A qualidade metodológica variou entre moderada e alta, com 75% dos estudos classificados com alta qualidade metodológica. Conclusões: A obesidade causa efeitos deletérios sobre os volumes e as capacidades pulmonares em crianças e adolescentes, com redução principalmente da capacidade residual funcional, volume de reserva expiratório e volume residual.

Laboratorio de función pulmonar / Lung function laboratory

El laboratorio de función pulmonar es esencial en el manejo de los pacientes con enfermedades respiratorias. El laboratorio de Clínica Las Condes realiza pruebas diagnósticas de uso habitual. El propósito de este artículo es revisar las indicaciones, limitaciones y la interpretación de éstas analizando también los aspectos técnicos, Estos exámenes son: Espirometría, volúmenes pulmonares, capacidad de difusión, test de metacolina, medición de la fracción exhalada de óxido nítrico y presión máximas inspiratorias y espiratorias, También se analizan los test de ejercicio realizados: test de marcha de seis minutos y test cardiopulmonar. Finalmente nos referimos a la oximetría nocturna como una forma de aproximarnos al diagnóstico de apnea del sueño.

Lung function tests are essential in the management of Respiratory patients. In Clinica Las Condes lab, we perform the most usual and important functional tests. The aim of this article is to review the indications, limitations and interpretation of them and also the technical aspects. This includes: Spirometry, lung volumes, DLCO, methacholine test, exhaled nitric oxide and maximum inspiratory and expiratory pressure. We also perform exercises tests like six minute walking and cardiopulmonary exercise test which we also describe. Finally, it is mention the nocturnal oximetry as an approximation to sleep apnea study.

Cardiorespiratory evaluation in pre and post operative moments of laparoscopic cholecystectomy

PURPOSE: To analyze the changes in both respiratory function and cardiopulmonary exercise tests results in patients subjected to laparoscopic cholecystectomy. METHODS: Fifty patients were evaluated (76% women) and the average age was 47.8±14.2 years. All individuals underwent the measurement of spirometry, manovacuometry, 6-minute walk test (6MWT) and stair-climbing test (SCT). All tests were performed at the first (PO1), fifth (PO5) and thirtieth (PO30) postoperative days. RESULTS: BMI average was 28.8±4.8 kg/m2. Sample comprised 68% non-smokers, 20% current smokers, and 12% former smokers. There was no incidence of postoperative complication whatsoever. There was a significant decrease in spirometric values at PO1, but values were similar to the ones of PRE at PO30. Manovacuometry showed alterations at PO1 displaying values that were similar to the ones of PRE at PO30. 6MWT was significantly shorter at until PO5, but at PO30 values were similar to ones of PRE. As for SCT, values were significantly compromised at PO5 and PO30 since they were similar to the ones of PRE. CONCLUSION: Patients submitted to laparoscopic cholecystectomy present a decrease in cardiorespiratory function on the first postoperative moments but there is a rapid return to preoperative conditions. .

Study of ventilatory lung function tests and aerobic capacity in overweight young adults.

Background & objectives : The deleterious effects of obesity on cardiovascular system have been well documented but their effects on the respiratory system and aerobic capacity have been overlooked. Thus this study was planned to assess ventilatory lung function tests and aerobic capacity in overweight young adults. Material and Methods: A total of 60 young students (18 to 22 years) were recruited in this study. They were divided in to 2 groups. Overweight group and control group. Pulmonary function tests (static and dynamic) were recorded on a computerized portable Schiller lung function unit. Aerobic capacity (VO2 max) was estimated by Queen’s College Step test. Data was analyzed by Students ‘t’ test. Results : In overweight group expiratory reserve volume , forced vital capacity, maximum ventilatory volume, forced expiratory volume at the end of first second and VO2 max were reduced as compared to control group. Interpretation and conclusion: These results indicate that increase in BMI may affect ventilatory lung function tests and aerobic capacity in young adults.

Valores de referência para espirometria em crianças pré-escolares / Reference values for spirometry in preschool children

OBJETIVOS: Valores de referência para testes de função pulmonar diferem em amostras de diferentes países, incluindo valores para pré-escolares. O objetivo principal do presente estudo foi derivar valores de referência em nossa população. MÉTODOS: Foi realizado estudo prospectivo, com aplicação de questionário a 425 crianças pré-escolares com idade variando entre três e seis anos, provenientes de escolas e creches públicas e privadas de uma cidade metropolitana do Brasil. As crianças foram selecionadas por amostragem aleatória simples dos referidos educandários. Foram avaliados: PFE, CVF, VEF1 VEF0,50, FEF25-75 e as relações: VEF1/CVF, VEF0,5/CVF e FEF25-75/CVF. RESULTADOS: Das 425 crianças recrutadas, 321 (75,6%) realizaram os testes. Destas, 135 (42,0%) apresentaram manobras aceitáveis, com curvas expiratórias completas e fizeram parte da análise de regressão para definir os valores de referência. Por análise de regressão linear e logarítmica, a estatura e o sexo influenciaram significativamente nas medidas de CVF. No sexo masculino, o r² se elevou com o modelo logarítmico, para a CVF e VEF1, porém o modelo linear foi mantido, por sua simplicidade. Os limites inferiores foram calculados através das medidas do 5º percentil dos resíduos. CONCLUSÃO: Curvas expiratórias completas são de mais difícil obtenção em pré-escolares. Além da estatura, o sexo também influencia nas medidas de CVF e VEF1. Foram definidos valores de referência para espirometria em crianças pré-escolares, nessa população, aplicáveis a populações semelhantes.

OBJECTIVES: Reference values for lung function tests differ in samples from different countries, including values for preschoolers. The main objective of this study was to derive reference values in this population. METHODS: A prospective study was conducted through a questionnaire applied to 425 preschool children aged 3 to 6 years, from schools and day-care centers in a metropolitan city in Brazil. Children were selected by simple random sampling from the aforementioned schools. Peak expiratory flow (PEF), forced vital capacity (FVC), forced expiratory volumes (FEV1, FEV0.50), forced expiratory flow (FEF25-75) and FEV1/FVC, FEV0.5/FVC and FEF25-75/FVC ratios were evaluated. RESULTS: Of the 425 children enrolled, 321 (75.6%) underwent the tests. Of these, 135 (42.0%) showed acceptable results with full expiratory curves and thus were included in the regression analysis to define the reference values. Height and gender significantly influenced FVC values through linear and logarithmic regression analysis. In males, R2 increased with the logarithmic model for FVC and FEV1, but the linear model was retained for its simplicity. The lower limits were calculated by measuring the fifth percentile residues. CONCLUSION: Full expiratory curves are more difficult to obtain in preschoolers. In addition to height, gender also influences the measures of FVC and FEV1. Reference values were defined for spirometry in preschool children in this population, which are applicable to similar populations.

Pulmonary manifestations in inflammatory bowel disease: a prospective study.

Background Although pulmonary abnormalities have been recognized in patients with inflammatory bowel diseases (IBD), their prevalence and clinical significance are not known. Aim To study the prevalence and clinical significance of pulmonary abnormalities in patients with IBD. Methods Ninety-five non-consecutive patients with IBD (12 Crohn’s disease, 83 ulcerative colitis; mean age 41.9 [SD 13] years; 47 women) were prospectively studied from January 2007 to March 2010. Pulmonary function tests (PFT) and high-resolution CT (HRCT) chest were performed in them. PFT were compared to those in 270 healthy (control) subjects matched for age, sex and smoking status. Results Twenty-seven (28.5%) patients and 11 (4%) control subjects had abnormal PFT (p<0.0001). Small airway obstruction was seen in 18 patients, restrictive defect in six and mixed defect in three. Twenty-one (22%) patients had abnormal HRCT findings – bronchiectasis and nodules (nine patients each, including one with nodules who later developed active tuberculosis after infliximab therapy), parenchymal bands (8), mediastinal lymphadenopathy (five, including two with tuberculosis on histology and culture), emphysema (5), brochiolitis (2), pleural effusion or thickening (2), pericardial effusion (2), patchy consolidation (1), ground-glass opacities (1) and lung metastasis (1). Three patients had symptoms (one asthma, two cough). Conclusion PFT and HRCT chest showed abnormality in about one-quarter of patients with IBD. A majority of patients with these abnormalities were asymptomatic.

Reduction in lung functions in type-2 diabetes in Indian population : Correlation with glycemic status.

The purpose of this study was to evaluate pulmonary functions in patients with Type-2 diabetes mellitus and to determine their correlation with glycemic status of diabetes in Indian population. Forty Type-2 diabetic patients, aged 30-60 years, with diabetic duration of 1-20 years, were included in the study. FVC, FEV1, & FEV1% are recorded by Benedict’s Roth spirometer. PEFR and MEP were recorded by Wright’s Peak flow meter & Modified Black’s apparatus. Glycemic status of subjects was determined by FBS & PPBS by Glucose oxidase & peroxidase methods. And results were analyzed by calculating Mean±SD, using Student’s t test, and Pearson correlation. All the respiratory parameters are reduced in Type- 2 diabetic patients compared to control of which FEV1, FEV1%, & MEP show very highly significant reduction (P=0.000). Lung functions are negatively correlated with glycemic status & duration of diabetes. (r = – 0.390, & –0.342) Reduction in dynamic lung functions and its negative correlation to glycemic status might be due to respiratory muscle weakness as indicated by highly significant reduction in MEP. Hence strict glycemic control and breathing exercises to strengthen the respiratory muscles may improve lung function in diabetics.

Evaluación de la respuesta broncodilatadora en pacientes secuelados de adenovirus / Assesment of bronchodilator response in post- adenovirus infection patients

Los pacientes con secuela de Adenovirus (SADV) presentan un patrón funcional respiratorio de obstrucción difusa de la vía aérea, y en algunas ocasiones restricción. En la espirometría generalmente no se demuestra respuesta broncodilatadora (RBD) significativa, e incluso se ha observado disminución de los flujos. Esta respuesta puede ser diferente si se mide Resistencia con técnicas realizadas a volumen corriente, como la Oscilometría de Impulso (IOS). El objetivo de este trabajo evaluar la respuesta broncodilatadora en pacientes con SADV a través de la IOS, comparado con la espirometría. En 19 pacientes con SADV en condición basal, se realizó una IOS y espirometría antes y 10 min después de la inhalación de 200 mcg de salbutamol, con un equipo Jaeger Master-Screen IOS, cumpliendo con los criterios de aceptabilidad y reproducibilidad determinados internacionalmente. Se consideró cambio significativo en la espirometría a 15% en VEF1, 30% en FEF25-75, FEF50 y FEF75; y en la IOS a 30% en la Resistencia a 5 htz (Rrs5) e Impedancia Total (Zrs) y 20% en Frecuencia de Resonancia (Fres). La edad promedio fue de 10 años (rango 2-16), 11 varones. Debido a la edad, no se pudo realizar espirometría a 2 niños. El promedio del porcentaje del predictivo de VEF1, CVF y Rrs5 basal fueron de 74%, 59% y 136%. El porcentaje de cambio postbroncodilatador fue de (X% ± SD) 3,4 ± 7 en VEF1, 8,6 ± 19 en FEF25-75, 11,5 ± 19 en FEF50, 10,4 ± 21 en FEF75, 27 ± 19 en Rrs5, 19 ± 12 en Fres y 21 ± 20 en Zrs. En los 17 niños que realizaron ambos exámenes, se encontró RBD significativa en 13 (76,4%) y 5 (29,4%) al ser evaluada con IOS y espirometría respectivamente. Si se evalúa sólo el VEF1, se encuentra RBD significativa en sólo 2 pacientes. La evaluación de la RBD con IOS en pacientes con SADV, demuestra que la mayoría de ellos se benefician con el broncodilatador, lo que generalmente no se observa con la espirometría.

Post Adenovirus infection (PADV) patients always have a diffuse airway obstruction, and sometimes a restrictive component too. Bronchodilator response is hardly present in the spirometry, and even it has been observed decrease of the flows. This response can be different if we measured Resistance during the tidal volume, like Impulse Oscillometry, instead of forced techniques like spirometry. The aim of this work was to evaluate the IOS bronchodilator response in PADV patients, compared with the spiromerty. Spiromety and IOS were measured correlatively using a Master Screen IOS in 19 PADV patients in baseline condition, before and after 10 minutes of reciving 200 mcg of salbutamol. Only the tests that complying with international approved acceptability and reproducibility criteria were accepted for the study. A change in the spirometry of 15% in FEV1, 30% in FEF25-75, FEF50 and FEF75; and a change in the IOS of 30% in the Resistance to 5 htz (Rrs5) and Total Impedance (Zrs) and 20% in Resonance Frequency (Fres) was consired a significant bronchodilator response. The mean age of the 19 PADV patients was 10 years (range 2-16), 11 were male. Because the short age spirometry could not be accomplished in 2 children. The baseline mean of the FEV1, CVF and Rrs5 of the predictive were 74%, 59% and 136%. The bronchodilator response was (X% ± SD) 3,4 ± 7 in FEV1, 8,6 ± 19 in FEF25-75, 11,5 ± 19 in FEF50, 10,4 ± 21 in FEF75, 27 ± 19 in Rrs5, 19 ± 12 in Fres and 21 ± 20 in Zrs. In 17 children that accomplished both exams, a significant bronchodilator response was found in 13 during the IOS (76,4%) and 5 during the spirometry (29,4%). A significant bronchodilator response in FEV1 was found in only 2 patients. Most of the PADV patients have a significant bronchodilator response, that it is demonstrated when it is measured with IOS, and generally is not observed with the spirometry.

FOLLOW-UP STUDY OF LUNG FUNCTION CHANGES FOR 10 YEARS IN THE ELDER PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASES AFTER WITHDRAWAL FROM SMOKING FOR 10 YEARS / 解放军医学杂志

To study changes of lung function for 10 years in the elder patients with chronic obstructive pulmonary diseases (COPD) who have quitted smoking for more than 10 years, 45 elder patients with COPD who had quitted smoking for more than 10 years were selected, and 11 elder patients with COPD who had never smoked were enrolled too. Routine lung function tests were performed. Initial values of VC, FVC, FEV 1 , PEF, MMEF, and MVV were compared with those 10 years later, and it was found the difference was significant ( P