Propiedades psicométricas de las escalas de gravedad de obstrucción bronquial en pediatría: Revisión sistemática y metaanálisis / Psychometric properties of scales used for grading the severity of bronchial obstruction in pediatrics: A systematic review and meta-analysis

Introducción. En pediatría, es determinante establecer precozmente la gravedad de la obstrucción bronquial (GOB). Objetivo. Evaluar las propiedades psicométricas de escalas de medición de GOB en pacientes pediátricos. Población y método. Revisión sistemática de estudios sobre validez y confiabilidad de escalas de GOB realizados en niños menores de 3 años. Se buscó en Medline, WoS, EMBASE, SciELO, Google Scholar. Los coeficientes de correlación de cada artículo fueron metaanalizados mediante el modelo de efectos aleatorios para determinar la validez de criterio y la confiabilidad a través de promedios ponderados de los coeficientes según el tamaño de la muestra. Resultados. Se incluyeron 9 artículos con un total de 2699 niños; 3 artículos presentaron calidad metodológica buena o excelente. Cuatro artículos determinaron la validez de criterio concurrente considerando la saturación de oxígeno; coeficiente de correlación ponderado -0,627 (IC 95%: de -0,767 a -0,431; p < 0,001); 2 artículos determinaron la validez de criterio convergente; coeficiente de correlación ponderado 0,809 (IC 95%: de 0,721 a 0,871; p < 0,001); 6 artículos determinaron la confiabilidad interobservador; coeficiente de correlación ponderado de 0,500 para kappa y 0,891 para coeficiente de correlación intraclase. Conclusión. La evaluación de las propiedades psicométricas para apoyar la utilidad de escalas para la estimación del constructo GOB mostró una validez de criterio de moderada a adecuada. El porcentaje de acuerdo entre observadores respecto de la medida observada (GOB) se muestra adecuado; sin embargo, hay que considerar las debilidades presentadas en el diseño de los artículos, lo cual podría afectar a la validez interna de los resultados.

Introduction. In pediatrics, identifying the severity of bronchial obstruction in an early manner is a decisive factor. Objective. To assess the psychometric properties of the scales for grading the severity of bronchial obstruction in pediatric patients. Population and Method. This was a systematic review of studies on the validity and reliability of scales for grading the severity of bronchial obstruction conducted in infants and children younger than 3 years old. The search was conducted in Medline, WoS, EMBASE, SciELO, and Google Scholar. The correlation coefficient corresponding to each article was included in a random effects model to establish the criterion validity and reliability using the weighted averages of coefficients as per the sample size. Results. A total of 9 articles were included, which accounted for 2699 children; 3 articles had an adequate or excellent methodological quality. Four articles established the concurrent criterion validity considering oxygen saturation, with a weighted correlation coefficient of -0.627 (95% confidence interval --#91;CI--#93;: -0.767 to -0.431, p 0.001); 2 articles established the convergent criterion validity, with a weighted correlation coefficient of 0.809 (95% CI: 0.721 to 0.871, p < 0.001); 6 articles established the inter-observer reliability, with a weighted correlation coefficient of0.500for kappa and 0.891 for the intraclass correlation coefficient. Conclusion. The assessment of psychometric properties to support the use of scales for grading the construct "severity of bronchial obstruction" showed a moderate to adequate criterion validity. The percentage of agreement among observers in terms of the studied measure (severity of bronchial obstruction) was adequate; however, weaknesses such as the article design should be taken into account since it may affect the internal validity of results.

Lung volumes and airway resistance in patients with a possible restrictive pattern on spirometry / Volumes pulmonares e resistência das vias aéreas em pacientes com possível padrão restritivo à espirometria

ABSTRACT Objective: Many patients with proportional reductions in FVC and FEV1 on spirometry show no reduction in TLC. The aim of this study was to evaluate the role that measuring lung volumes and airway resistance plays in the correct classification of patients with a possible restrictive pattern on spirometry. Methods: This was a prospective study involving adults with reduced FVC and FEV1, as well as an FEV1/FV(C) ratio within the predicted range. Restrictive lung disease (RLD) was characterized by TLC below the 5th percentile, as determined by plethysmography. Obstructive lung disease (OLD) was characterized by high specific airway resistance, significant changes in post-bronchodilator FEV1, or an FEF25-75% < 50% of predicted, together with a high RV/TLC ratio. Nonspecific lung disease (NLD) was characterized by TLC within the predicted range and no obstruction. Combined lung disease (CLD) was characterized by reduced TLC and findings indicative of airflow obstruction. Clinical diagnoses were based on clinical suspicion, a respiratory questionnaire, and the review of tests of interest. Results: We included 300 patients in the study, of whom 108 (36%) were diagnosed with RLD. In addition, 120 (40%) and 72 (24%) were diagnosed with OLD/CLD and NLD, respectively. Among the latter, 24 (33%) were clinically diagnosed with OLD. In this sample, 151 patients (50.3%) were obese, and obesity was associated with all patterns of lung disease. Conclusions: Measuring lung volumes and airway resistance is often necessary in order to provide an appropriate characterization of the pattern of lung disease in patients presenting with a spirometry pattern suggestive of restriction. Airflow obstruction is common in such cases.

RESUMO Objetivo: Muitos pacientes com redução proporcional de CVF e VEF1 na espirometria não têm CPT reduzida. O objetivo deste estudo foi avaliar o papel da medida dos volumes pulmonares e da resistência das vias aéreas para a classificação correta de pacientes com possível restrição à espirometria. Métodos: Estudo prospectivo de adultos com CVF e VEF1 reduzidos e relação VEF1/CV(F) na faixa prevista. Distúrbio ventilatório restritivo (DVR) foi definido por CPT < 5º percentil por pletismografia. Distúrbio ventilatório obstrutivo (DVO) foi caracterizado por resistência específica de vias aéreas elevada, resposta significativa do VEF1 pós-broncodilatador e/ou um FEF25-75% < 50% do previsto associado a uma relação VR/CPT elevada. Distúrbio ventilatório inespecífico (DVI) foi caracterizado por CPT na faixa prevista e ausência de obstrução. Distúrbio ventilatório combinado (DVC) foi caracterizado por CPT reduzida e achados indicativos de obstrução ao fluxo aéreo. Os diagnósticos clínicos foram baseados em suspeita clínica, um questionário respiratório e revisão de exames de interesse. Resultados: Foram incluídos 300 pacientes no estudo, dos quais 108 (36%) tiveram diagnóstico de DVR, enquanto 120 (40%) foram diagnosticados com DVO ou DVC e 72 (24%) com DVI. Destes últimos, 24 (33%) tinham diagnóstico clínico de DVO. Nesta amostra, 151 pacientes (50,3%) eram obesos, e isso se associou com todos os padrões de distúrbios funcionais. Conclusões: Medidas dos volumes pulmonares e da resistência das vias aéreas são frequentemente necessárias para a caracterização adequada do tipo de distúrbio funcional em casos com possível restrição à espirometria. A obstrução ao fluxo aéreo é comum nesses casos.

O "cansaço" como categoria norteadora das experiências de adoecidos pulmonares / "Fatigue" as a guiding category for the experiences of pulmonary diseased

As doenças pulmonares obstrutivas crônicas (DPOC) e as fibroses pulmonares intersticiais têm recebido pouca atenção da antropologia. Bastante estudadas do seu ponto de vista fisiológico e terapêutico, vale também atentar para seu quadro social, especialmente porque a debilidade provocada pelo comprometimento pulmonar e a oxigenoterapia, geralmente prescrita nas últimas etapas do adoecimento, são quadros que dependem de um arranjo familiar e clínico bastante complexo. Em particular, neste artigo, repousarei o foco sobre o "cansaço", uma categoria bastante central para as pessoas entrevistadas ao narrarem suas experiências com as DPOC. Ao todo, 28 pessoas foram entrevistadas em suas casas, muitas vezes em companhia de suas cuidadoras, numa grande metrópole brasileira, a partir de roteiro semiestruturado. O cansaço figura como principal sintoma identificado e referido ao longo dos itinerários diagnósticos e terapêuticos pelos diferentes serviços de saúde da cidade, de menor a maior complexidade. O cansaço retoma, ao final, como categoria que descreve também a busca que adoecidos e familiares empreenderam por atendimento, internação, medicação e disponibilização dos equipamentos para a oxigenoterapia domiciliar. Ao final, discuto alguns dos motivos que levaram os entrevistados a concentrar sua longa resposta na busca por tratamento, embora essa etapa tenha acontecido há muitos anos. Atenta à forma e ao conteúdo das narrativas dos adoecidos, conforme sugere Arthur Frank, percebo como pode ser mais heroico essas pessoas escolherem contar aventuras, sobressaltos e coragem no passado (quando buscavam os primeiros atendimentos), do que falar sobre dependência, enfado e cansaço, no presente (quando enfrentam o cotidiano da oxigenoterapia paliativa).

Abstract Chronic obstructive pulmonary diseases (COPD) and pulmonary fibrosis have received little attention from Anthropology. Studied from the physiological and therapeutical perspectives, their social conundrum is also worthy of note, especially because the weakness caused by pulmonary limitation and oxygen therapy-usually prescribed during the last stages of the disease-depend on complex familial and clinical arrangements. In particular, this paper will focus on "fatigue", as the central category pointed out by the respondents that narrated their experiences with COPD. In total, 28 people were interviewed in their home-usually in the company of their caretakers-in a big Brazilian metropolis, using a semi-structured list of questions. Fatigue was the main symptom identified and referred throughout the diagnostic and therapeutic itineraries around different health services-of lower and higher complexity-of the city. Fatigue resumes, in the end, as a category that also describes the search the respondents and their families endured for treatment, hospitalization, medication and in-home oxygen therapy equipment. In the end, I discuss some of the reasons that led respondents to focus their long answers in the search for treatment, although the search took place a long time ago. Form and content of the narratives are taken into account, as suggested by Arthur Frank, and I realize that it can be more heroic to tell tales of adventure, overcoming, and courage in the past (when they searched for the first treatments); than tales of dependence, boredom, and fatigue in the present (when they have to deal with daily palliative oxygen therapy).

Vitamin D deficiency is independently associated with mortality among critically ill patients

OBJECTIVE: Studies suggest an association between vitamin D deficiency and morbidity/mortality in critically ill patients. Several issues remain unexplained, including which vitamin D levels are related to morbidity and mortality and the relevance of vitamin D kinetics to clinical outcomes. We conducted this study to address the association of baseline vitamin D levels and vitamin D kinetics with morbidity and mortality in critically ill patients. METHOD: In 135 intensive care unit (ICU) patients, vitamin D was prospectively measured on admission and weekly until discharge from the ICU. The following outcomes of interest were analyzed: 28-day mortality, mechanical ventilation, length of stay, infection rate, and culture positivity. RESULTS: Mortality rates were higher among patients with vitamin D levels <12 ng/mL (versus vitamin D levels >12 ng/mL) (32.2% vs. 13.2%), with an adjusted relative risk of 2.2 (95% CI 1.07-4.54; p< 0.05). There were no differences in the length of stay, ventilation requirements, infection rate, or culture positivity. CONCLUSIONS: This study suggests that low vitamin D levels on ICU admission are an independent risk factor for mortality in critically ill patients. Low vitamin D levels at ICU admission may have a causal relationship with mortality and may serve as an indicator for vitamin D replacement among critically ill patients. .

Prevalence of Spirometrically-defined Restrictive Ventilatory Defect in Korea: The Fourth-2, 3, and Fifth Korean National Health and Nutrition Examination Survey, 2008-2012

The aim of the study was to evaluate the prevalence of restrictive ventilatory defect and to determine the risk factors in subjects with spirometrically-defined restrictive ventilatory defect. We used the population-based, fourth-2, 3 (2008, 2009) and fifth (2010-2012) Korea National Health and Nutrition Examination Survey (KNHANES) to analyze 15,073 subjects, aged > or =40 yr who underwent spirometry. Chest radiographs were also analyzed to identify restrictive lung disease. Spirometrically-defined restrictive ventilatory defect (FEV1/FVC> or =70% and FVC or =40 yr. The prevalence increased to 12.3% on using the lower limit of normal (LLN) criteria. Approximately 99.4% of subjects were classified as mild restrictive. Among these, 11.3% had inactive tuberculosis (TB) lesion, 2.2% cardiac disease, 2.0% previous operation scar or radiation injury and/or mediastinal disease, and 7.4% other pulmonary disease suggestive of restrictive lung diseases on chest radiograph. Evidence of previous TB history was independently associated with restrictive ventilatory defect (odds ratios [OR], 1.78; 95% confidence interval, 1.45-2.18) after adjustment for gender, age, smoking, area for residence and body mass index. The prevalence of restrictive ventilatory defect among the nationwide population in Korea was 11.3% with fixed ratio criterion and 12.3% with LLN criterion. Most cases were of the mild restrictive category and previous TB history is the independent risk factor for restrictive ventilatory defect.

Effect of Airflow Limitation on Acute Exacerbations in Patients with Destroyed Lungs by Tuberculosis

History of treatment for tuberculosis (TB) is a risk factor for obstructive lung disease. However, it has been unclear whether the clinical characteristics of patients with destroyed lung by TB differ according to the presence or absence of airflow limitation. The objective of the study was to evaluate differences in acute exacerbations and forced expiratory volume in 1 second (FEV1) decline in patients with destroyed lung by TB according to the presence or absence of airflow limitation. We performed a retrospective cohort study and enrolled patients with destroyed lung by TB. The presence of airflow limitation was defined as FEV1/forced vital capacity (FVC) < 0.7. One hundred and fifty-nine patients were enrolled, and 128 (80.5%) had airflow limitation. The proportion of patients who experienced acute exacerbation was higher in patients with airflow limitation compared to those without (89.1 vs. 67.7%, respectively; P = 0.009). The rate of acute exacerbation was higher in patients with airflow limitation (IRR, 1.19; 95% CI, 1.11-1.27). Low body mass index (X vs. X + 1; HR, 0.944; 95% CI, 0.895-0.996) in addition to airflow limitation (HR, 1.634; 95% CI, 1.012-2.638), was an independent risk factor for acute exacerbation. The annual decline of FEV1 was 2 mL in patients with airflow limitation and 36 mL in those without (P < 0.001). In conclusion, the presence of airflow limitation is an independent risk factor for acute exacerbation in patients with the destroyed lung by TB.

Can the single-breath helium dilution method predict lung volumes as measured by whole-body plethysmography? / Pode o metodo de diluicao do helio em respiracao unica estimar os volumes pulmonares medidos pela pletismografia de corpo inteiro?

OBJECTIVE: To compare TLC and RV values obtained by the single-breath helium dilution (SBHD) method with those obtained by whole-body plethysmography (WBP) in patients with normal lung function, patients with obstructive lung disease (OLD), and patients with restrictive lung disease (RLD), varying in severity, and to devise equations to estimate the SBHD results. METHODS: This was a retrospective cross-sectional study involving 169 individuals, of whom 93 and 49 presented with OLD and RLD, respectively, the remaining 27 having normal lung function. All patients underwent spirometry and lung volume measurement by both methods. RESULTS: TLC and RV were higher by WBP than by SBHD. The discrepancy between the methods was more pronounced in the OLD group, correlating with the severity of airflow obstruction. In the OLD group, the correlation coefficient of the comparison between the two methods was 0.57 and 0.56 for TLC and RV, respectively (p < 0.001 for both). We used regression equations, adjusted for the groups studied, in order to predict the WBP values of TLC and RV, using the corresponding SBHD values. It was possible to create regression equations to predict differences in TLC and RV between the two methods only for the OLD group. The TLC and RV equations were, respectively, ∆TLCWBP-SBHD in L = 5.264 − 0.060 × FEV1/FVC (r2 = 0.33; adjusted r2 = 0.32) and ∆RVWBP-SBHD in L = 4.862 − 0.055 × FEV1/FVC (r2 = 0.31; adjusted r2 = 0.30). CONCLUSIONS: The correction of TLC and RV results obtained by SBHD can improve the accuracy of this method for assessing lung volumes in patients with OLD. However, additional studies are needed in order to validate these equations. .

OBJETIVO: Comparar resultados de CPT e VR obtidos pelo método de diluição de hélio em respiração única (DHRU) com aqueles obtidos por pletismografia de corpo inteiro (PCI) em indivíduos com função pulmonar normal, portadores de distúrbio ventilatório obstrutivo (DVO) e portadores de distúrbio ventilatório restritivo (DVR) com diferentes níveis de gravidade e elaborar equações para estimar CPT e VR por DHRU. MÉTODOS: Estudo transversal retrospectivo com 169 indivíduos, dos quais, respectivamente, 93, 49 e 27 apresentavam DVO, DVR e espirometria normal. Todos realizaram espirometria e determinação de volumes pulmonares pelos dois métodos. RESULTADOS: Os valores de CPT e VR foram maiores por PCI que por DHRU. A discrepância entre os métodos foi mais acentuada no grupo com DVO e se relacionou com a gravidade da obstrução ao fluxo aéreo. No grupo com DVO, o coeficiente de correlação da comparação entre os dois métodos foi de 0,57 e 0,56 para CPT e VR, respectivamente (p < 0,001 para ambos). Para predizer os valores de CPT e VR por PCI utilizando os respectivos valores por DHRU foram utilizadas equações de regressão, corrigidas de acordo com os grupos estudados. Somente foi possível criar equações de regressão para predizer as diferenças de CPT e VR entre os dois métodos para pacientes com DVO. Essas equações foram, respectivamente, ∆CPTPCI-DHRU em L = 5,264 − 0,060 × VEF1/CVF (r2 = 0,33; r2 ajustado = 0,32) e ∆VRPCI-DHRU em L = 4,862 − 0,055 × VEF1/CVF (r2 = 0,31; r2 ajustado = 0,30). CONCLUSÕES: A correção de CPT e VR obtidos por DHRU pode melhorar a acurácia desse método para avaliar os volumes pulmonares em pacientes com DVO. Entretanto, estudos adicionais ...

Capnografia volumétrica como meio de detectar obstrução pulmonar periférica precoce em pacientes com fibrose cística / Volumetric capnography as a tool to detect early peripheric lung obstruction in cystic fibrosis patients

OBJETIVO: Comparar a espirometria e a capnografia volumétrica (CapV) para determinar se os valores amostrados pela capnografia acrescentam informações sobre doenças pulmonares precoces em pacientes com fibrose cística (FC). MÉTODOS: Este foi um estudo do tipo corte transversal envolvendo pacientes com FC: Grupo I (42 pacientes, 6-12 anos de idade) e Grupo II (22 pacientes, 13-20 anos de idade). Os grupos controle correspondentes eram formados por 30 e 50 indivíduos saudáveis, respectivamente. A capacidade vital forçada (CVF), o volume expiratório forçado no primeiro segundo (VEF1) e a relação VEF1/CVF foram determinados pela espirometria. Através da CapV, medimos a saturação periférica de oxigênio (SpO2), a frequência respiratória (FR), o tempo inspiratório (TI), o tempo expiratório (TE) e o slope da fase III normalizado pelo volume corrente (slope da fase III/Vc). RESULTADOS: Em comparação com os grupos controle, todos os pacientes com FC apresentaram valores de slope da fase III/Vc (p < 0,001) mais altos independentemente do estágio de doença pulmonar. O slope da fase III/Vc foi significantemente mais alto nos 24 pacientes que tiveram resultados normais de espirometria (p = 0,018). Os pacientes do Grupo II apresentaram valores de CVF, VEF1, VEF1/CVF (p < 0,05) e SpO2 (p < 0,001) mais baixos que os pacientes do Grupo I. Os pacientes do Grupo II, comparados com os do Grupo Controle II, apresentaram FR (p < 0,001) mais alta e valores de TI e TE (p < 0,001) mais baixos. CONCLUSÕES: Todos os pacientes com FC mostraram ter valores mais altos de slope da fase III/Vc quando comparados com os pacientes dos grupos controle. A CapV identificou a heterogeneidade da distribuição da ventilação nas vias aéreas periféricas dos pacientes com FC que apresentaram espirometria normal.

OBJECTIVE: To compare spirometry and volumetric capnography (VCap) to determine if the capnographic values add more information about early lung disease in cystic fibrosis (CF) patients. METHODS: This was a cross-sectional study involving CF patients: Group I (42 patients, 6-12 years of age); and Group II (22 patients, 13-20 years of age). The corresponding control groups were comprised of 30 and 50 healthy subjects, respectively. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and the FEV1/FVC ratio was determined by spirometry. Using VCap, we measured peripheral oxygen saturation (SpO2), respiratory rate (RR), inspiratory time (IT), expiratory time (ET), and the phase III slope normalized by expiratory volume (phase III slope/Ve). RESULTS: In comparison with control groups, all CF patients presented higher phase III slope/Ve values (p < 0.001) independent of the pulmonary disease stage. The phase III slope/Ve was significantly higher in the 24 patients who presented normal spirometry results (p = 0.018). The Group II patients showed lower FVC, FEV1, FEV1/FVC (p < 0.05), and also lower SpO2 values (p < 0.001) when compared with Group I patients. In comparison with Control Group II, the Group II patients presented higher RR (p < 0.001), and lower IT and ET values (p < 0.001). CONCLUSIONS: Compared to the controls, all studied CF patients showed an increase in phase III slope/Ve values. VCap identified the heterogeneity of the ventilation distribution in the peripheral airways of CF patients who presented normal spirometry.

Tabacosis, un cambio de terminología para un aumento de conciencia / Tabacosis, a change in therminology for an increase increase in consciousness

Ante la ausencia de definición categórica de la Real Academia Española, tenemos que la Enfermedad Pulmonar Obstructiva Crónica (EPOC) es prevenible y tratable, con afectación sistémica extrapulmonar, donde el componente pulmonar se caracteriza por limitación al flujo del aire que no es completamente reversible y es progresivo. Esta es probablemente una de la definiciones médicas con mayor cantidad de posiciones e intereses encontrados y es que, indudable y lastimosamente, las siglas EPOC, fueron del gremio médico, no tiene mayor significancia, pues diariamente se encuentra gran cantidad de pacientes portadores de esta patología, que no tiene noción real de su padecimiento, el cual con mucho costo es aclarado por el médico tratante, debido a lo engorroso de su significado, variedad de síntomas y múltiples patologías causadas. Estas vicisitudes, en cuanto a la patología causal de EPOC, son las que la han convertido en el "cajón" donde se colocan diversas neumopatías que no tienen un origen específico, sin importar si presenta o no obtrucción al flujo aéreo; además, estos inconvenientes sobre terminología, hacen dificultosa la realización de búsquedas bibliográcas, por la poca acogida que ha tenido el término.

O papel da razão FEF50 por cento/0.5CVF no diagnóstico dos distúrbios ventilatórios obstrutivos / The role of the FEF50 percent/0.5FVC ratio in the diagnosis of obstructive lung diseases

OBJETIVO: Avaliar a contribuição de um novo coeficiente, a razão FEF50 por cento/0,5CVF, medida através da curva fluxo-volume máximo expiratório, no diagnóstico dos distúrbios ventilatórios obstrutivos (DVOs); testar esse coeficiente na diferenciação entre grupos de pacientes normais, com DVO e com distúrbio ventilatório restritivo (DVR); e estabelecer pontos de corte para cada um dos diagnósticos funcionais e a probabilidade para cada diagnóstico a partir de valores individuais. MÉTODOS: Estudo transversal, prospectivo, com a análise de testes de função pulmonar de 621 pacientes encaminhados ao Hospital de Clínicas de Porto Alegre entre janeiro a dezembro de 2003. Foram coletados dados demográficos e espirométricos. Os pacientes foram divididos conforme o diagnóstico funcional em três grupos: normal; DVO; e DVR. Foram calculadas as razões VEF1/CVF e FEF50 por cento/0,5CVF, e as médias de FEF50 por cento/0,5CVF foram comparadas entre os grupos. Para correlacionar FEF50 por cento/0,5CVF com VEF1/CVF, utilizou-se a correlação de Pearson. Os pacientes foram, então, divididos em dois grupos: com e sem DVO. Foram calculadas as razões de verossimilhança para diferentes pontos de corte. RESULTADOS: A média de idade dos pacientes foi de 55,8 ± 14,7 anos. Houve diferenças significativas nos valores médios de FEF50 por cento/0,5CVF entre os grupos (2,10 ± 0,82, 2,55 ± 1,47 e 0,56 ± 0,29, respectivamente, para normal, DVR e DVO; p < 0,001). Houve uma correlação positiva do FEF50 por cento/0,5CVF com VEF1/CVF no grupo DVO (r = 0,83). Valores de FEF50 por cento/0,5CVF < 0,79 mostraram-se fortes indicadores de DVO e valores > 1,33 praticamente afastam esse diagnóstico. CONCLUSÕES: A razão FEF50 por cento/0,5CVF é um parâmetro potencialmente útil para discriminar DVOs, correlacionando-se positivamente com o VEF1/CVF.

OBJECTIVE: To evaluate the contribution of a new coefficient, the FEF50 percent/0.5FVC ratio, obtained from the maximal expiratory flow-volume curve, to the diagnosis of obstructive lung disease (OLD); to test this coefficient in differentiating among patients considered normal, those with OLD and those with restrictive lung disease (RLD); and to determine cut-off points for each functional diagnosis, as well as the probability for each diagnosis based on individual values. METHODS: A prospective, cross-sectional study analyzing the pulmonary function of patients referred to the Porto Alegre Hospital de Clínicas, in Porto Alegre, Brazil, between January and December of 2003. We collected demographic and spirometric data. The patients were divided into three groups: normal; OLD; and RLD. We calculated the FEV1/FVC and FEF50 percent/0.5FVC ratios, and we compared the mean FEF50 percent/0.5FVC values among the groups. We used Pearson's correlation test in order to compare FEF50 percent/0.5FVC with FEV1/FVC. The patients were again divided into two groups: those with OLD and those without OLD. We calculated the likelihood ratio for different cut-off points. RESULTS: The mean age of the patients was 55.8 ± 14.7 years. There were significant differences among the groups in terms of the mean FEF50 percent/0.5FVC (2.10 ± 0.82, 2.55 ± 1.47 and 0.56 ± 0.29, respectively, for normal, RLD and OLD; p < 0.001). There was a positive correlation between FEF50 percent/0.5FVC and FEV1/FVC in the OLD group (r = 0.83). We found that an FEF50 percent/0.5FVC < 0.79 strongly suggests OLD, whereas an FEF50 percent/0.5FVC > 1.33 practically excludes this diagnosis. CONCLUSIONS: The FEF50 percent/0.5FVC ratio is a potentially useful parameter in the differential diagnosis of OLD and correlates positively with the FEV1/FVC ratio.

Lipoma de traqueia simulando doença pulmonar obstrutiva / Tracheal lipoma mimicking obstructive lung disease

Os tumores de traqueia são raros e podem ser de difícil diagnóstico, por mimetizarem outras afecções pulmonares de caráter obstrutivo, como asma e DPOC. Relatamos um caso de lipoma de traqueia em uma paciente que fora tratada para asma e DPOC, sem resposta adequada, até apresentar complicações infecciosas. A presença do tumor foi sugerida por TC de tórax e confirmada por fibrobroncoscopia. A paciente foi submetida à ressecção endoscópica do tumor; porém, evoluiu para o óbito por pneumonia e choque séptico.

Tracheal tumors are rare and can be difficult to diagnose due to their capacity to mimic other obstructive lung diseases, such as asthma and COPD. We report the case of a female patient with a tracheal tumor. She had previously been treated for asthma and COPD, with little response to the treatment. The onset of infectious complications prompted further investigation. Chest CT images suggested the presence of a tumor, which was confirmed by fiberoptic bronchoscopy. The tumor was endoscopically resected. However, the patient evolved to death due to pneumonia and septic shock.

Oscilometría de impulso (IOS) en niños / Impulse oscillometry in children

Este artículo tiene como propósito revisar aspectos fisiológicos, técnicos y clínicos de la oscilometría de impulso aplicada en pediatría; ya que en la actualidad tiene un rol importante en el estudio de la mecánica respiratoria. Es una interesante aproximación al diagnóstico funcional del sistema respiratorio por su fácil realización; en cuanto no necesita de la cooperación activa del paciente, se obtienen resultados comprensibles del sitio y magnitud de la alteración, puede complementar las pruebas de provocación, pesquizar precozmente la respuesta broncodilatadora y participar en el seguimiento de enfermedades crónicas.

Prueba de caminata de seis minutos / Guidelines for the six-minute walk test

The six-minute walk test has been shown as a very useful tool in the functional assessment of patients with chronic respiratory diseases enclosing patients with pulmonary hypertension. Methodological standardization of this test is fundamental for interpreting its results, as well as for using it in the short and long-term clinical follow up of our patients. The purpose of these guidelines is justly to spread out in our country the proper way to perform this useful test. In this context, indications, contraindications, limitations, security measures and detailed instructions about how to carry out, how to report and how to interpret the 6 minute walk test are described in these guidelines.

La prueba de caminata de 6 minutos ha demostrado ser una herramienta muy útil en la evaluación funcional de los pacientes con enfermedades respiratorias crónicas, incluyendo pacientes con hipertensión pulmonar. Para su correcta interpretación y uso clínico en el seguimiento de pacientes, es fundamental estandarizar la técnica. El propósito de este instructivo es justamente difundir a nivel nacional, la manera de efectuar esta técnica en forma correcta. En este contexto, este instructivo describe las indicaciones, contraindicaciones, limitaciones, medidas de seguridad y entrega detalles sobre la ejecución, informe e interpretación de la prueba de caminata de 6 minutos.

Guía clínica de enfermedad pulmonar obstructiva crónica (EPOC): parte I: diagnóstico / Clinical guideline of chronic obstructive pulmonary disease (COPD): part I: diagnosis

Chronic obstructive pulmonary disease (COPD) is characterized by the presence of chronic obstructive and poorly reversible airway obstruction secondary to an abnormal inflammatoryreaction mainly against the smoke snuff. This is an entity that is often underdiagnosed and that his diagnosis and staging requires the realization of a spirometry which should show varyingdegrees of obstruction to expiratory flow. In the clinical assessment is important to establish the magnitude of smoking, as well as the intensity of the designs and its progression. If thesmoking does not disclose the bronchial obstruction must questioning about other pollutants, especially intradomiciliary with exposure to wood smoke. This first part of the guide discusses the clinical diagnostic criteria assessing the severity and criteria for referral of COPD.

Valor de la espirometría para el diagnostico de restricción pulmonar / Accuracy of spirometry in the diagnosis of pulmonary restriction

Un defecto ventilatorio restrictivo está caracterizado por una reducción en la capacidad pulmonar total. El objetivo de este estudio fue evaluar la utilidad de la espirometría para determinar la presencia de restricción en pacientes con y sin obstrucción bronquial. Fueron incluídos 520 pacientes. Se definieron los valores normales mediante el intervalo de confianza del 95% (IC) utilizando la ecuación de Morris para la espirometría, y la de la European Respiratory Society (ERS) para capacidad pulmonar. Las espirometrías fueron clasificadas como obstructivas cuando mostraban relación volumen espiratorio forzado en 1 segundo (VEF1)/capacidad vital forzada (CVF) < 70% + VEF1 menor al límite inferior por IC. En los pacientes sin obstrucción espirométrica (n = 357) la sensibilidad y especificidad fueron 42.2% y 94.3% respectivamente, el valor predictivo negativo (VPN) fue 86.6% y el VP positivo (VPP) 65.2%. En el grupo de pacientes con obstrucción espirométrica (n = 66) la sensibilidad aumentó al 75.8% con una especificidad de 65.9%. El VPP disminuyó a sólo 57.8% y el VPN fue del 81.5%. Los pacientes con obstrucción y falsos positivos de CVF disminuida (n = 22) tuvieron los mismos valores de CVF (57.36 ± 13.45 vs. 58.82 ± 8.71%, p = 0.6451), de VEF1 (44.73 ± 19.24 vs. 44.0 ± 13.08%, p = 0.8745) y de difusión de monóxido de carbono (DLCO) (67.50 ± 27.23 vs. 77.00 ± 16.00%, p = 0.1299) que los pacientes verdaderos positivos. En conclusión, nuestros datos dan soporte experimental a la recomendación de no interpretar una CV o una CVF disminuida como evidencia de restricción en presencia de una relación VEF1/ CVF disminuida. La definición de defectos "mixtos" en la espirometría es inexacta e inaceptable.

A restrictive ventilatory defect is characterized by a decreased total lung capacity (TLC). The objective of this study was to determine the accuracy of spirometry to detect pulmonary restriction in patients with or without airflow obstruction in the spirometry. Five hundred and twenty patients were included. Normal values for lung function were determined by using the 95% confidence interval (CI) with Morris reference equation for spirometry and European Respiratory Society equation for lung volume. Spirometries were considered obstructive when FEV1/FVC ratio was <70% and FEV1 was below 95%CI. In patients without obstruction in the spirometry (n = 357) sensitivity and specificity were 42.2% and 94.3% respectively, negative predictive value (NPP) was 86.6% and positive PV (PPV) was 65.2%. In patients with an obstructive spirometry (n = 66) sensitivity increased to 75.8% but specificity decreased to 65.9%. PPV was only 57.8% and NPV 81.5%. Patients showing obstruction in the spirometry and false positives of a low FVC (n = 22) had similar values of FVC (57.36 ± 13.45 vs. 58.82 ± 8.71%, p = 0.6451), FEV1 (44.73 ± 19.24 vs. 44.0 ± 13.08%, p = 0.8745) and DLCO (67.50 ±27.23 vs. 77.00 ±16.00%, p = 0.1299) than true positives. Residual volume (RV) (125.72 ± 64. vs. 77.96 ± 29.98%, p = 0.0011) and RV/ TLC ratio (56.89 ± 12.82 vs. 38.43 ± 13.07%, p = <0.0001) were significantly higher. We conclude that a decreased FVC or VC cannot be considered evidence of ventilatory restriction in the presence of airflow obstruction on spirometry. Diagnosis of "mixed defects" by spirometry is inaccurate and should be avoided without the measurement of lung volumes.

Variáveis capnográficas pré e pós-tromboendarterectomias pulmonares / Pre and post-pulmonary thromboendarterectomies campnographic variables

Este relato de dois casos com os resultados da fração tardia de espaço morto (fDlate), fração do espaço morto alveolar end-tidal (AVDSf), gradiente artério-alveolar de CO2 [P(a-et)CO2] e slope da fase 3 do espirograma, submetidos à tromboendarterectomia pulmonar por tromboembolismo pulmonar (TEP). O TEP foi diagnosticado pela cintilografia pulmonar, tomografia helicoidal computadorizada e por arteriografia pulmonar. O cálculo da fDlate, AVDSf e P(a-et)CO2 baseou-se na capnografia volumétrica associada à gasometria arterial. A fDlate préoperatória do primeiro paciente foi de 0,16 (cutoff de 0,12) e a AVDSf = 0,30 (cutoff de 0,15). Já a fDlate do segundo paciente resultou falso-negativa (0,01), embora a AVDSf resultasse positiva (0,28). A fDlate pós-operatória do primeiro paciente foi de -0,04 e a AVDSf de 0,16; a fDlate do segundo paciente foi de 0,07 e a AVDSf = 0,28. A associação destas variáveis com os exames por imagem reforça a importância deste método como ferramenta diagnóstica não-invasiva no diagnóstico de TEP.

In these case report, the results of late dead space fraction (fDlate), end-tidal alveolar dead space fraction (AVDSf), arterial-alveolar gradient CO2 [P(a-et)CO2], and slope phase 3 of spirogram of two patients who underwent thromboendarterectomy for pulmonary embolism (PE) are shown. PE was diagnosed by pulmonary scintigraphy, helical tomography, and pulmonary angiography. The calculation of fDlate, AVDSf and P(a-et)CO2 was based on volumetric capnography associated with arterial blood gas analysis. The pre-operative fDlate of the first patient was 0.16 (cutoff 0.12) and AVDSf was 0.30 (cutoff 0.15). However, the fDlate of the second patient was false-negative (0.01) but, the AVDSf was positive (0.28). Postoperative fDlate of the first patient was -0.04 and AVDSf was 0.16; for the second patient, the values were 0.07 and 0.28, respectively. The association of these capnographic variables with image exams reinforces the importance of this noninvasive diagnosis method.

Programa de cessação de tabagismo como ferramenta para o diagnóstico precoce de doença pulmonar obstrutiva crônica / Smoking cessation program as a tool for the early diagnosis of chronic obstructive pulmonary disease

OBJETIVO: A doença pulmonar obstrutiva crônica (DPOC) é subdiagnosticada e subtratada, o que resulta em subestimação do impacto da doença. O objetivo deste estudo foi avaliar se a inclusão da espirometria na avaliação dos fumantes que ingressam em programas de cessação do tabagismo contribui para o diagnóstico precoce da DPOC. MÉTODOS: Análise retrospectiva de dados médicos de 158 fumantes atendidos no programa cessação de tabagismo (Faculdade de Medicina de Botucatu, São Paulo, Brasil), de janeiro 2003 a novembro 2005. Todos os indivíduos tinham mais de 40 anos (idade média: 55 ± 8,5 anos), sendo 99 (62,6 por cento) do sexo feminino. Foram analisados os dados clínicos, os diagnósticos médicos prévios e os resultados da espirometria. RESULTADOS: Dos 158 fumantes avaliados, 57 (36,1 por cento) indivíduos preenchiam os critérios diagnósticos para DPOC e 14 (8,9 por cento) foram considerados em risco para o desenvolvimento da doença. Dos 57 que preenchiam os critérios diagnósticos para DPOC, 39 (68,4 por cento) foram diagnósticos novos e 18 (31,6 por cento) foram confirmação de diagnóstico prévio da doença. Entre os 18 com diagnóstico anterior, 10 (56 por cento) tinham doença leve/moderada e 8 (44 por cento) doença grave. Sete pacientes com diagnóstico anterior de DPOC apresentaram resultados de função de pulmonar não compatíveis com os critérios diagnósticos da doença. Entre os 39 novos diagnósticos, 38 (97,4 por cento) eram de doença leve/moderada e apenas 1 (2,6 por cento) tinha DPOC grave CONCLUSÃO: A inclusão da espirometria na avaliação inicial dos fumantes admitidos em programa de cessação de tabagismo pode ser uma ferramenta útil para o diagnóstico precoce da DPOC.

OBJECTIVE: The impact of chronic obstructive pulmonary disease (COPD) is underestimation as a result of underdiagnosis and undertreatment. The objective of this study was to determine whether using spirometry to evaluate smokers enrolled in smoking cessation programs facilitates early diagnosis of COPD. METHODS: The medical records of 158 smokers enrolled in the smoking cessation program at the Botucatu School of Medicine (Botucatu, Brazil) between January of 2003 and November of 2005 were evaluated retrospectively. All were over 40 years old (mean age: 55 ± 8.5 years), and 99 (62.6 percent) were female. We analyzed the clinical data, the previous medical diagnosis, and the spirometry results. RESULTS: The diagnostic criteria for COPD were met by 57 (36.1 percent) of the 158 individuals evaluated, and 14 individuals (8.9 percent) were considered to be at risk for the development of the disease. Of those 57 individuals meeting the criteria for a diagnosis of COPD, 39 (68.4 percent) were receiving their first diagnosis of COPD, whereas 18 (31.6 percent) were receiving confirmation of a prior diagnosis. Of the 18 individuals previously diagnosed, 10 (56 percent) presented the mild/moderate form of the disease, and 8 (44 percent) presented the severe form. Of the 39 newly diagnosed individuals, 38 (97,4 percent) presented the mild/moderate for of the disease, and only 1 (2,6 percent) had severe COPD. Seven patients previously diagnosed with COPD presented pulmonary function test results inconsistent with the diagnostic criteria. CONCLUSION: Using spirometry in the initial evaluation of smokers enrolling in smoking cessation program might be a useful tool for early diagnosis of COPD.

La relación entre el asma y la enfermedad pulmonar obstructiva crónica / The relation between the asthma and chronic respiratory pulmonary disease

Asma y enfermedad pulmonar obstructiva crónica (EPOC) son enfermedades pulmonares comunes con semejanza y diferencias. Estudios genéticos recientes han dado información importante acerca de los múltiples loci susceptibles para cada enfermedad. Estudios del genoma han mostrado resultados similares en al menos una región crosomal en ambas enfermedades, así como también evidencia la interacción con factores ambientales (por ejemplo, el fumado activo en los pacientes con EPOC, o el pasivo en aquellos con asma). Existen pocos estudios recientes acerca del remodelamiento de la vía aérea y su importancia en pacientes asmáticos persistentes crónicos, lo que podría explicar de cierta forma la progresión de estas personas a enfermedades pulmonares obstructivas crónicas.