The Prognostic Value of Residual Volume/Total Lung Capacity in Patients with Chronic Obstructive Pulmonary Disease

The prognostic role of resting pulmonary hyperinflation as measured by residual volume (RV)/total lung capacity (TLC) in chronic obstructive pulmonary disease (COPD) remains poorly understood. Therefore, this study aimed to identify the factors related to resting pulmonary hyperinflation in COPD and to determine whether resting pulmonary hyperinflation is a prognostic factor in COPD. In total, 353 patients with COPD in the Korean Obstructive Lung Disease cohort recruited from 16 hospitals were enrolled. Resting pulmonary hyperinflation was defined as RV/TLC > or = 40%. Multivariate logistic regression analysis demonstrated that older age (P = 0.001), lower forced expiratory volume in 1 second (FEV1) (P < 0.001), higher St. George Respiratory Questionnaire (SGRQ) score (P = 0.019), and higher emphysema index (P = 0.010) were associated independently with resting hyperinflation. Multivariate Cox regression model that included age, gender, dyspnea scale, SGRQ, RV/TLC, and 6-min walking distance revealed that an older age (HR = 1.07, P = 0.027), a higher RV/TLC (HR = 1.04, P = 0.025), and a shorter 6-min walking distance (HR = 0.99, P < 0.001) were independent predictors of all-cause mortality. Our data showed that older age, higher emphysema index, higher SGRQ score, and lower FEV1 were associated independently with resting pulmonary hyperinflation in COPD. RV/TLC is an independent risk factor for all-cause mortality in COPD.

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 ...

Validation of a protocol to evaluate maximal expiratory pressure using a pressure transducer and a signal conditioner

The respiratory muscles can present fatigue and even chronic inability to generate force. So, reliable devices are necessary to their evaluation. The aim of this study is to evaluate the MEP (Maximal Expiratory Pressure) values of individuals between 20 and 25 years old and to validate a protocol using a pressure transducer and a signal conditioner comparing it with the digital manometer. We evaluated the MEP of 10 participants. They remained seated and made six respiratory maneuvers from Total Lung Capacity (TLC) to Residual Volume (RV). The results in the study showed no statistically significant differences when compared to values reported in the literature, and that the pressure transducer provides reliable values for MEP.

Os músculos respiratórios podem apresentar fadiga e até mesmo a incapacidade crônica na geração de força, sendo necessários dispositivos confiáveis para sua avaliação. O objetivo deste estudo foi avaliar a pressão expiratória máxima (PeMáx) de indivíduos entre 20 e 25 anos e validar um protocolo que utiliza um transdutor de pressão e um condicionador de sinais comparando-o com a manovacuometria. Foram avaliadas a PeMáx de 10 participantes. Estes permaneceram sentados e realizaram seis manobras respiratórias a partir da capacidade pulmonar total (CPT) até o volume residual (VR). Os resultados do estudo não apresentaram diferenças estatisticamente significativas quando comparados com os valores de normalidade descritos na literatura e mostraram que o transdutor de pressão fornece valores confiáveis para Pe máx.

Función pulmonar y calidad de vida en niños y adolescentes con bronquiolitis obliterante por adenovirus / Pulmonary function and quality of life in children and adolescents with bronchiolitis obliterans post-adenoviral infection

Introduction: Adenovirus infection is an important cause of pneumonia in Chilean children. Postinfectious Bronchiolitis Obliterans (PIBO) is the most important complication. There are few studies assessing pulmonary function and quality of life in PIBO patients. Objective: The aim of this study is to assess the pulmonary function and the quality of life of patients with PIBO and the correlation between both variables. Methods: 14 children with PIBO in follow up at the pediatric pulmonology outpatient clinic of a public children hospital were included in this study. Study period: April 2009 - April 2010. Pulmonary function was assessed in a medical visit by spirometry, flow/volume curve and intrathoracic gas volume measurement. The following indices were analyzed FVC, FEV1, FEV25-75, FEV1/FVC, RV, TLC, RV and RV/TLC. A survey of a self-administered Quality of Life (PedsQL, version 4.0, Spanish for Chile) was applied at the visit to investigate their global, physical and psychosocial quality of life. The Pearson linear correlation between quality of life and the pulmonary function test parameters was assessed, in the statistical analysis ap value < 0.05 was considered significant. Results: The mean age of our patients was 12.4 (range: 9-19 years-old). The functional alterations were characteristics of an obstructive respiratory disorder in 64.3 percent of the patients. Average pulmonary function test indices showed decreases in FEV1 (75 percent), FEV25-75 (48.8 percent), FEV1/FVC (67.6 percent) with normal value of FVC (93,7 percent) as well as pronounced increases in RV (333.5 percent), TLC (156 percent) and RV/TLC (51.8 percent). Mean change of FEV1 and FEV25-75post-bronchodilator was 11.3 percent and 26.4 percent respectively. Only 14.3 percent of our patients showed normal pulmonary function. The quality of life parameters were in average 58.2 percent of overall quality of life, 58.6 percent of physical quality of life and 57.9 percent of psychosocial ...

Introducción: La infección por adenovirus es una causa importante de neumonía en niños chilenos. La bronquiolitis obliterante (BOPI) es la complicación más importante. Existen pocos estudios donde evalúen la función pulmonar y la calidad de vida de los pacientes con BOPI. Objetivo: Evaluar la función pulmonar y la calidad de vida de los pacientes con BOPI y la correlación entre ambas variables. Métodos: Se incluyeron 14 niños con BOPI en el policlínico de la unidad de broncopulmonar de un hospital público de niños. Período de estudio: abril de 2009-abril de 2010. La función pulmonar se evaluó en una visita médica por espirometría, curva flujo / volumen y la determinación de volumen de gas intratorácico. Los índices analizados fueron los siguientes CVF, VEF1, FEV25-75, VEF1/CVF, VR,CPT, VR y VR / CPT. En la misma visita se realizó una encuesta auto-administrada de Calidad de Vida (PedsQL, versión 4.0, español de Chile) para investigar la calidad de vida global, física y psi-cosocial. Se aplicó la correlación lineal de Pearson entre calidad de vida y los parámetros de función pulmonar. Se consideró estadísticamente significativo unp <0,05. Resultados: La edad media de nuestros pacientes fue de 12,4 (rango: 9-19 años). La alteración funcional característica fue la obstructiva en el 64,3 por ciento de los pacientes. El promedio de los índices de pruebas de función pulmonar mostraron una disminución en VEF1 (75 por ciento), FEV25-75 (48,8 por ciento), VEF1/CVF (67,6 por ciento) con un valor normal de la CVF (93,7 por ciento), así como aumentos pronunciados en VR (333,5 por ciento), CPT (156 por ciento) y VR/CPT (51,8 por ciento). La media del cambio del VEF1 y FEV25-75post-broncodilatador fue 11,3 por ciento y 26,4 por ciento respectivamente. Sólo el 14,3 por ciento mostró una función pulmonar normal. Los parámetros de calidad de vida fueron en promedio 58,2 por ciento de calidad de vida general, 58,6 por ciento de calidad de vida física y el 57,9 por ciento...

Variación del volumen espiratorio forzado y presión de oxígeno en reducción del volumen pulmonar en bullas gigantes unilaterales / Variation of the forced expiratory volume and oxygen pressure in the reduction of pulmonary volume in unilateral giant bullas

Se presentan 15 enfermos con bullas enfisematosas gigantes, tratados mediante lobectomía reglada en el Hospital Universitario Comandante Manuel Fajardo, en el período de 1995 a 2000; todos estos pacientes se abordaron mediante incisiones axilares y en el 100 (por ciento) eran del sexo masculino fumadores de 2 cajetillas de cigarros diarios. La mortalidad quirúrgica fue del 6,6 (por ciento) a causa de que uno de los pacientes falleció por trombolismo pulmonar. En los 14 enfermos restantes se valoraron las pruebas funcionales respiratorias y se observó un cambio del volumen espiratorio forzado de disminución del volumen residual. En la gasometría arterial, la presión de oxígeno (PO2) aumentó en todos los enfermos hasta valores entre 80 y 85 lo que les permitió incorporarse a su vida laboral activa(AU)

15 patients with giant emphysematous bullas treated by ruled lobectomy at Comandante Manuel Fajardo Teaching Hospital, from 1995 to 2000, were presented. All these patients were approached by axillary incisions. 100 percent were males who smoked 2 packages of cigarettes daily. Surgical mortality was 6.6 percent due to the fact that one of the patients died from pulmonary trombolism. In the other 14 patients the functional respiratory tests were made and it was observed a change of the forced expiratory volume in the reduction of the residual volume. In the arterial gasometry, the oxygen pressure (02P) increased in all patients, reaching values between 80 and 85, which allowed them to incorporate to their active working life(AU)