Pulmonary function tests in compressed natural gas pump workers in Surat city

Background: Various studies have known abatements in lung function and several other health problems associated with longstanding air pollution exposure. One of the most cost-effective and environmental alternative of conventional fuels (petrol and diesel) is compressed natural gas (CNG). The increasing use of CNG as a fuel (as it is safe and cheap as compare to the conventional fuels) can add one more bug to the list of work-related disease. Aims and Objectives: This study is to evaluate the respiratory functions of CNG pump workers. Materials and Methods: The present study was held on 82 male subjects. The study group included of non-smoking healthy adult males, age group of 20–40 years working in different CNG stations in Surat city for >6 months and 8 h per day. The control group included of non-smoking healthy adult males, age group of 20–30 years working or studying in the Surat Municipal Institute of Medical Education and Research (SMIMER). Results: Out of 82 male subjects, 30 subjects were control and 52 subjects were CNG station workers. The study group comprised of 52 healthy non-smokers in the age group of 20–40 years working in different CNG station in Surat city for >6 months and 8 h/day. The control group comprised of 30 healthy non-smokers males between the age group of 20–30 years working or studying in the SMIMER. Conclusion: In this study, we have not found statistically significant deterioration in pulmonary functions of CNG pump workers when compared to controls.

Development of a Multi-parameter Pulmonary Function Test System / 中国医疗器械杂志

To comprehensively evaluate the human body's respiratory, circular metabolism and other functions, and to diagnose lung disease, an accurate and reliable pulmonary function test (PFT) is developed. The system is divided into two parts:hardware and software. It realizes the collection of respiratory, pulse oxygen, carbon dioxide, oxygen and other signals, and draws flow-volume curve (FV curve), volume-time curve (VT curve), respiratory waveform, pulse wave, carbon dioxide and oxygen waveform in real time on the upper computer of the PFT system, and conducts signal processing and parameter calculation for each signal. The experimental results prove that the system is safe and reliable, it can accurately measure the basic functions of human body, and provide reliable parameters, and has good application prospects.

Validation and reproducibility of the COPD-PS questionnaire for the screening of COPD: Bogotá, Colombia

Abstract Introduction: Chronic obstructive pulmonary disease is a condition with high prevalence worldwide. It is preventable and treatable, but with very high levels of underdiagnosis. The use of screening tools is imperative. These tools are easily applied, interpreted, and validated in different populations and help not only the clinician to confirm the diagnostic suspicion, but also the patients to become aware of their disease. The objective is to validate the COPD-Population Screener Questionnaire (COPD-PS) in one Colombian population. Materials and Methods: A prospective cohort study was carried out. Participants had to be older than 40 years, show a good quality spirometry, and have completed the COPD-PS questionnaire twice. COPD was defined as FEV1/FVC < 0.7 and with a history of exposure to tobacco smoke. A reproducibility and validation analysis has been conducted. Result: Out of a total of 2.199 potential subjects, 1.662 entered the final analysis; the prevalence of COPD in the study was 21.1%. With the COPD-PS questionnaire cut-off point of four, the sensitivity was 77.2% and the specificity was 46.3%, with an area under the receiver operating characteristic curve of: 0.66 (95% CI: 0.63-0.69) (p<0.01). An intraclass correlation coefficient of 0.817 (95% CI: 0.79-0.84) and a kappa coefficient of: 0.45 (95% CI: 0.31-0.59) (p<0.01) were obtained. Conclusion: The COPD-PS questionnaire is a tool with high sensitivity and good reproducibility for the screening of COPD, and could suggest the use of a spirometry in subjects not diagnosed with this disease.

Evaluación del riesgo quirúrgico pulmonar en la cirugía del cáncer del pulmón durante la pandemia de COVID 19 / Evaluation of pulmonary surgical risk in surgery of the lung cancer during the COVID 19 pandemic

La evaluación del riesgo quirúrgico pulmonar es obligatoria antes de considerar el tratamiento quirúrgico de los estadíos iniciales del cáncer del pulmón. La espirometría y la capacidad de difusión expresadas en porcentaje del valor teórico y del valor predicho posoperatorio son las pruebas iniciales para realizar la evaluación. En virtud de la pandemia COVID-19 se han establecido normas de bioseguridad y prevención para la realización de dichas pruebas. Aquellos pacientes que no reúnan condiciones para la cirugía de acuerdo a los valores preestablecidos deben realizar pruebas adicionales antes de ser descartados para el tratamiento quirúrgico. La prueba de la escalera puede constituirse en un instrumento útil para ese fin dada la falta de disponibilidad de la prueba de ejercicio cardiopulmonar por su contraindicación en las actuales circunstancias de la pandemia COVID-19 y la escasez de equipos para su realización en nuestro medio

The assessment of the preoperative pulmonary risk is compulsory before considering the surgical treatment of early stage lung cancer. The spirometry and diffusion capacity expressed in percentages of the theoretical and predicted postoperative values are the initial tests necessary to carry out the assessment. Taking into account the COVID-19 pandemic, some biosafety and prevention rules have been established for doing such tests. Patients who do not meet certain conditions for surgery in accordance with previously established values shall do additional tests before disregarding surgical treatment. The Step Test may be a useful tool for that purpose, since the cardiopulmonary exercise test is unavailable, given its contraindication under the current circumstances of the COVID-19 pandemic and the shortage of equipment for doing it

Correlation of Six Minute Walk Test and Lung Function Test Variables (% FEV1, % FVC, % DLCO) in Patients with Connective Tissue Disorder - Interstitial Lung Disease

Interstitial Lung Diseases (ILDs) also known as diffuse parenchymal lung disease, include a group of diffuse parenchymal infiltrative lung diseases. A restrictive defect is the most frequent pulmonary abnormality in patients with pulmonary fibrosis which is the usual consequence of many ILDs. Connective tissue disorders are usually rare, but are potentially life threatening conditions. The spectrum of ILD varies from mucocutaneous symptoms, arthralgia / arthritis to impairment of pulmonary and renal function. Systemic Lupus Erythematosus (SLE), Systemic Sclerosis (SSc), Sjogren’s Syndrome (SS), inflammatory muscle diseases and overlap-syndromes are grouped together as connective-tissue disorders. Involvement of lung and its function is the most common form of interstitial lung disease, leading to high morbidity and mortality among the group of connective tissue disorders. We wanted to correlate the 6-Min Walk Distance (6MWTD) with the Pulmonary Function Test values such as % FEV1, % FVC and FEV1 / FVC, among patients with connective tissue disorder associated Interstitial Lung Disease in SRM Medical College Hospital, a tertiary care hospital in Tamilnadu, South India. MethodsThis study was done as a cross sectional analytical study among 31 patients in the Department of Respiratory Medicine, Rheumatology and General Medicine in SRM medical college and hospital. Each patient was explained the purpose of the study and the need for complete co-operation. Those who satisfied the inclusion and exclusion criteria were included. Data was collected using a structured proforma. 6-minute walk test and pulmonary function tests were performed and correlated. ResultsThere appears to be a significant correlation between 6-minute walk test, % desaturation, 6 Minute Walk Test Distance, 6 Minute Walk Test Pre BDI and 6 Minute Walk Test Post BDI with spirometry values especially with the Spirometry FEV 1 %, Spirometry FVC % and % predicted DLCO. Conclusions6MWT can be used as a useful surrogate for pulmonary function tests especially among the population where spirometry is not possible. 6MWT has good reproducibility, is simple to perform and can be used as a screening tool for Interstitial Lung Disease in connective tissue disorder patients.

Diabetes and Deteriorating Lung Function Based on Spirometry: A Narrative Review

Background: Many pulmonary dysfunctions are noted in both type 1 and 2 diabetes. This dysfunction can be mechanical in terms of muscle tone or strength, functional in terms of diffusion capacity or gaseous exchange and chemical with regards to mediators. Many hypothesis or mechanisms were proposed and changed along the course of time to support the issue. The studies have shown an increased evidence of lung dysfunction changes in diabetes, both at a time or during the course of time. So the lung complications should also be considered among micro vascular complications to actively search for a better prognosis. Aim: To study the association of diabetes and lung function based on spirometry. Materials and methods: We identified all studies in English Language that evaluated the association of diabetes mellitus and lung function using keywords like “diabetes, lung volume, lung function, diabetes micro angiopathy, spirometry” across various published research articles using Google Scholar Data Base. Conclusion: From our narrative review, a conclusion was made that both varieties of diabetes, type 2 and type1 have reduced lung functions as reviewed by spirometry not only due to adverse events like pneumonia but also due to the extensive period of consequence of diabetes which may be because of micro angiopathy or diminished elastic recoil capability of lungs.

An under studied co-relation of diabetes and lung function

The World Health Organization estimates that more than 180 million people worldwide have diabetes, and by 2030 it is expected that this number will have doubled. There is an alarming increase in the incidence and prevalence of diabetes mellitus (DM) in Asian Indians. Epidemiology of Diabetes in India. The prevalence of diabetes is rapidly rising all over the globe at an alarming rate . Over the past 30 years, the status of diabetes has changed from being considered as a mild disorder of the elderly to one of the major causes of morbidity and mortality affecting the youth and middle aged people. Pulmonary function test (PFT) is a complete evaluation of the respiratory system including patient history, physical examinations, and tests of pulmonary function. with insulin-dependent diabetes compared with age-matched control subjects, all lifelong non-smokers. Lung CO transfer capacity is significantly affected by the integrity of lung capillary endothelium and, therefore, the findings of Sandler et al. focused attention on pulmonary vascular changes. The concept of the lung as a target organ for diabetic microangiopathy received continuing attention. Reports of lung function tests in patients with diabetes over the next 15 years have focused largely on pulmonary microangiopathy with relatively few studies of pulmonary mechanical function which leads to a restrictive lung pattern. Diabetes and Lung Function Test : Some studies showed that all the pulmonary parameters, that is, FVC, FEV1, FEF25, FEF50, FEF75, FEF25–75, FEF0.2–1.2, and PEFR were significantly reduced except FEV1/FVC in patients of type 2 DM as compared with the healthy controls. It can be concluded from our narrative review that the Type II or Type I diabetes is definitely having decreased lung functions assessed by spirometry not only because of diabetic complications like pneumonia or other but also due to long term effect of diabetes may be because of micro-angiopathy or decreased elastic recoil capacity of lungs.

Effect of Exposure to 2.5 μm Indoor Particulate Matter on Adult Lung Function in Jakarta

OBJECTIVES: Lung function impairment due to exposure to indoor air pollution of particulate matter size 2.5 micrometers (PM2.5) is not well documented in Jakarta. METHODS: To assess whether there is an association between indoor PM2.5 concentration and lung function impairment among the adult population, a cross-sectional design was implemented. There were 109 adults selected aged between 20 years and 65 years from the Pulo Gadung industrial area, East Jakarta. Association and logistic regression analysis were implemented for statistical analysis of the data. RESULTS: The average exposure to indoor PM2.5 was 308 μg/m3. There were 38.5% of participants that had lung function impairment. PM2.5 concentration was found to be associated with lung function impairment among the adult population living in Pulo Gadung industrial area after controlling for gender, duration of exposure, ventilation, smoking status, and humidity. CONCLUSION: The results of this study suggest that PM2.5 concentrations in the Pulo Gadung industrial area may be the main contributor to the impairment of lung function for adults living in the surrounding residential area.

Correlation between Physical Activity and Lung Function in Dusty Areas: Results from the Chronic Obstructive Pulmonary Disease in Dusty Areas (CODA) Cohort / 결핵

BACKGROUND: Although physical activity is known to be beneficial to lung function, few studies have been conducted to investigate the correlation between physical activity and lung function in dusty areas. Therefore, the purpose of this study is to investigate the correlation between physical activity and lung function in a Korean cohort including normal and COPD-diagnosed participants. METHODS: Data obtained from the COPD in dusty areas (CODA) cohort was analyzed for the following factors: lung function, symptoms, and information about physical activity. Information on physical activity was valuated using questionnaires, and participants were categorized into two groups: active and inactive. The evaluation of the mean lung function, modified Medical Research Council dyspnea grade scores, and COPD assessment test scores was done based on the participant physical activity using a general linear model after adjusting for age, sex, smoking status, pack-years, height, and weight. In addition, a stratification analysis was performed based on the smoking status and COPD. RESULTS: Physical activity had a correlation with high forced expiratory volume in 1 second (FEV₁) among CODA cohort (p=0.03). While the active group exhibited significantly higher FEV₁ compared to one exhibited by the inactive group among past smokers (p=0.02), no such correlation existed among current smokers. There was no significant difference observed in lung function after it was stratified by COPD. CONCLUSION: This study established a positive correlation between regular physical activity in dusty areas and lung function in participants.

Comparative Analysis of Lung Perfusion Scan and SPECT/CT for the Evaluation of Functional Lung Capacity / 대한핵의학회잡지

PURPOSE: This study aimed to compare lung perfusion scan with single photon emission computed tomography/computed tomography (SPECT/CT) for the evaluation of lung function and to elucidate the most appropriate modality for the prediction of postoperative lung function in patients with lung cancer.METHODS: A total of 181 patients underwent Tc-99m macroaggregated albumin lung perfusion scan and SPECT/CT to examine the ratio of diseased lung and diseased lobe. Forty-one patients with lung cancer underwent both preoperative and postoperative pulmonary function tests within 1 month to predict postoperative pulmonary function. Predicted postoperative forced expiratory volume in 1 s (ppoFEV₁) was calculated by the % radioactivity of lung perfusion scan and SPECT, and the % volume of the residual lung, assessed on CT.RESULTS: The ratios of diseased lung as seen on lung perfusion scan and SPECT showed significant correlation, but neither modality correlated with CT. The ratios of the diseased lung and diseased lobe based on CT were higher than the ratios based on either perfusion scan or SPECT, because CT overestimated the function of the diseased area. The lobar ratio of both upper lobes was lower based on the perfusion scan than on SPECT but was higher for both lower lobes. Actual postoperative FEV₁ showed significant correlation with ppoFEV₁ based on lung perfusion SPECT and perfusion scan.CONCLUSIONS: We suggest SPECT/CT as the primary modality of choice for the assessment of the ratio of diseased lung area. Both perfusion scan and SPECT/CT can be used for the prediction of postoperative lung function.

Kinesiología respiratoria en pacientes asmáticos en edad escolar / Respiratory physiotherapy in asthmatic school-age patients

The role of respiratory physiotherapy in the asthmatic school-age patient is based on three pillars: evaluative, therapeutic and educational, which have gradually been incorporated and developed. Respiratory physiotherapy has advanced significantly, incorporating cardiorespiratory function tests into its diagnostic and follow-up services, allowing the execution of these tests at the primary level of healthcare. Manual and instrumental respiratory physiotherapy techniques increase the level of control of asthmatic patients. The evidence found in literature invites us to innovate the methodology we use at educational interventions in children and adolescents, with the inclusion of new technologies to motivate and generate meaningful learning in patients as well as in their parents/caregivers, thus improving adherence to treatment and achieving the desired control of the disease

El rol de la kinesiología respiratoria en el paciente asmático en etapa escolar, se basa en tres pilares: evaluativo, terapéutico y educativo, los cuales se han ido paulatinamente incorporando y desarrollando con el paso del tiempo. La kinesiología respiratoria ha avanzado significativamente, incorporando pruebas de función cardiorrespiratoria a su arsenal de prestaciones diagnósticas y de seguimiento, permitiendo la ejecución de éstas en el nivel primario de atención. Mediante la utilización de técnicas manuales e instrumentales, permite potenciar el nivel de control de los pacientes asmáticos. La literatura nos invita a innovar en la metodología a utilizar para realizar una intervención educativa efectiva en niños y adolescentes, incluyendo las nuevas tecnologías disponibles para motivar y generar un aprendizaje significativo en el paciente como en los padres/cuidadores, mejorando así la adherencia al tratamiento y por ende logrando el anhelado control de la enfermedad

Thoracic changes and exercise capacity in patients with adolescent idiopathic scoliosis / Alterações torácicas e capacidade de exercício em pacientes com escoliose idiopática do adolescente

Abstract Introduction: The spine deformity due to adolescent idiopathic scoliosis (AIS) generates respiratory mechanical limitations that may reduce the physical activity performance. Objective: To evaluate the thoracic deformity, exercise capacity and lung function in AIS patients comparing to healthy adolescentes. Besides investigating associations between thoracic deformity and exercise capacity in AIS patients. Methods: Thirty-two AIS patients and 22 healthy adolescents underwent chest wall evaluation by photogrammetry. We created thoracic markers shaped as angles (A): A3 (xiphoid process and the last false rib on the right and left sides) and A5E (inframamilar / inferior angle of the scapula / left acromion). Individuals were submitted to incremental shuttle walk test (ISWT) and physiological responses were quantified: oxygen consumption (VO2), tidal volume (VT), minute ventilation (VE), the rate of gas exchange (R) and the walked distance (ISWD). Pulmonary function test was performed and the forced vital capacity (FVC) and expiratory volume in first second (FEV1) were obtained. Results: Patients with AIS presented FVC (p = 0.015), FEV1 (p = 0.044), VO2 (p = 0.015), VO2/kg (p = 0.008), VT (p < 0.001), VE (p = 0,010) and ISWD significantly reduced compared to healthy adolescents. We found moderate correlations between the thoracic markers A5E and VO2 (r = -0.480, p = 0.001), A3 and VE/VO2 (r = -0.480; p = 0.001) and R (r = -0.480, p = 0.001) in AIS patients. Conclusion: Patients with AIS presented reduced exercise capacity and reduced pulmonary function. The thoracic deformity is related to worse exercise capacity in individuals with AIS.

Resumo Introdução: A deformidade da coluna vertebral causada pela escoliose idiopática do adolescente (EIA) gera limitações respiratórias que podem reduzir o desempenho da atividade física. Objetivo: Avaliar a deformidade torácica, capacidade de exercício e função pulmonar em pacientes com EIA comparando com adolescentes saudáveis. Além de investigar associações entre a deformidade torácica e capacidade de exercício em pacientes com EIA. Métodos: Trinta e dois pacientes com EIA e 22 adolescentes saudáveis foram submetidos à avaliação da caixa torácica por fotogrametria. Criamos marcadores torácicos em forma de ângulos (A): A3 (processo de xifóide e as últimas costelas falsas bilateral) e A5E (inframamilar/ângulo inferior da escápula/acrômio esquerdo). Os indivíduos foram submetidos ao Incremental Shuttle Walk Test (ISWT) e respostas fisiológicas foram quantificadas: consumo de oxigênio (VO2), volume corrente (VT), ventilação minuto (VE), taxa de troca gasosa (R) e a distância percorrida (ISWD). A função pulmonar foi realizada e a capacidade vital forçada (CVF) e o volume expiratório forçado no primeiro segundo (VEF1) foram obtidos. Resultados: Os pacientes com EIA apresentaram CVF (p = 0,015), VEF1 (p = 0,044), VO2 (p = 0,015), VT (p < 0,001), VE (p = 0,010) e ISWD significantemente reduzidos em relação ao controle. Encontramos correlações moderadas entre A5E e VO2 (r = -0,480, p = 0,001), A3 e VE/VO2 (r = -0,480; p = 0,001) e R (r = -0,480, p = 0,001) em pacientes com EIA. Conclusão: Pacientes com EIA apresentaram redução da capacidade de exercício e da função pulmonar e a deformidade torácica está relacionada à pior capacidade de exercício nestes indivíduos.

Spirometry reference values in the Brazilian population

The aim of the present study was to provide new spirometry reference equations in a sample of the Brazilian population for the following parameters: forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC ratio, peak of expiratory flow (PEF), forced expiratory flow at 50% (FEF50%), 75% average vital capacity (FEF25-75%), and average forced expiratory flow time (FEFT). This was a prospective study using results from chest radiographs, electrocardiograms, and questionnaires to investigate the participants' respiratory symptoms, sedentarism, and comorbidities (Charlson comorbidity index). From December 2010 to July 2014, individuals were randomly selected from various locations in the state of Rio de Janeiro. All individuals were examined by a single technician in the morning at the laboratory, and performed the spirometry with the same spirometer. Spirometry values were tabulated for the creation of three equation models: linear regression, logarithmic regression, and logarithms through a method that incorporates the lambda, median, and coefficient of variation (LMS method). Initially, 7003 individuals from both genders were contacted, and 454 were recruited. The data from the new equations were compared with one Brazilian and eight international equations, resulting in a high correlation (r>0.9). The values derived from the LMS method and linear regression were very similar (P>0.5), and both could be used to acquire the reference values for Brazilian spirometry. Data derived from the equations of this study were different from the current Brazilian equation, which could be justified by the different method used.

Prevalence of asthma-like symptoms and assessment of lung function in schoolchildren born with low birth weight

<p><b>INTRODUCTION</b>This study aimed to determine the prevalence of asthma-like symptoms among schoolchildren with low birth weight (LBW), and to compare the lung function of these children with that of children with normal birth weight.</p><p><b>METHODS</b>This was a comparative cross-sectional study. We recruited children aged 8-11 years from eight primary schools in Kota Bharu, Kelantan, Malaysia. The children were divided into two groups: those with LBW (< 2,500 g) and those with normal birth weight (≥ 2,500 g). Parents of the enrolled children were asked to complete a translated version of the International Study of Asthma and Allergies in Childhood questionnaire. Lung function tests, done using a MicroLoop Spirometer, were performed for the children in both groups by a single investigator who was blinded to the children's birth weight.</p><p><b>RESULTS</b>The prevalence of 'ever wheezed' among the children with LBW was 12.9%. This value was significantly higher than that of the children with normal birth weight (7.8%). Forced vital capacity (FVC), forced expiratory volume in one second, and forced expiratory flow when 50% and 75% of the FVC had been exhaled were significantly lower among the children with LBW as compared to the children with normal birth weight.</p><p><b>CONCLUSION</b>LBW is associated with an increased prevalence of asthma-like symptoms and impaired lung function indices later in life. Children born with LBW may need additional follow-up so that future respiratory problems can be detected early.</p>

Association of wheezing phenotypes with fractional exhaled nitric oxide in children / 소아과

Asthma comprises a heterogeneous group of disorders characterized by airway inflammation, airway obstruction, and airway hyperresponsiveness (AHR). Airway inflammation, which induces AHR and recurrence of asthma, is the main pathophysiology of asthma. The fractional exhaled nitric oxide (FeNO) level is a noninvasive, reproducible measurement of eosinophilic airway inflammation that is easy to perform in young children. As airway inflammation precedes asthma attacks and airway obstruction, elevated FeNO levels may be useful as predictive markers for risk of recurrence of asthma. This review discusses FeNO measurements among early-childhood wheezing phenotypes that have been identified in large-scale longitudinal studies. These wheezing phenotypes are classified into three to six categories based on the onset and persistence of wheezing from birth to later childhood. Each phenotype has characteristic findings for atopic sensitization, lung function, AHR, or FeNO. For example, in one birth cohort study, children with asthma and persistent wheezing at 7 years had higher FeNO levels at 4 years compared to children without wheezing, which suggested that FeNO could be a predictive marker for later development of asthma. Preschool-aged children with recurrent wheezing and stringent asthma predictive indices also had higher FeNO levels in the first 4 years of life compared to children with wheezing and loose indices or children with no wheeze, suggesting that FeNO measurements may provide an additional parameter for predicting persistent wheezing in preschool children. Additional large-scale longitudinal studies are required to establish cutoff levels for FeNO as a risk factor for persistent asthma.

Lung function tests in preschool children / 소아과

Measurement of lung function is an integral component of respiratory physiology and of clinical assessment of lung diseases in school age children and adults. Pulmonary function test of infants and children under the age of 2 years have now been standardised and are being used both in research and as an adjunct to clinical management. By contrast, until recegntly, children of preschool age, i.e. between 2-6 years represented a major challenge for pulmonary function test assessment, this particular period commonly being referred to as the 'dark ages' of Pediatric Pulmonology. Measurement of lung function in preschool-aged children is now feasible. However, much work remains to be done in standardizing how these tests are performed, and in understanding the most appropriate role for the various tests in the study of growth and development of the respiratory system and in the clinical management of children in this age group. As the field develops and the knowledge of respiratory physiology in this age group expands, investigation of different and more appropriate algorithm use in preschool children, together with development of more appropriate reference data, may result in improved disease discrimination.

Reference values for respiratory system impedance using impulse oscillometry in school-aged children in Korea / 소아과

PURPOSE: The impulse oscillometry (IOS) is applicable to young children because it requires minimal cooperation and a non-invasive method to measure the mechanics of respiratory system. This study aimed to develop the reference values in school-aged children in Korea, using IOS which is a modification of forced oscillation technique (FOT). METHODS: Measurements were performed in 92 previously untrained healthy children, aged 7 to 12 years old, using IOS. We analyzed the relationships between the data about their age, height, weight, body surface area (BSA), body mass index (BMI) and the result of IOS using the linear regression test. RESULTS: The success rate of IOS was 92.4%. Stepwise multiple regression of resistance of respiratory system (Rrs) and reactance of respiratory system (Xrs) in natural form for age, height, weight, BSA, BMI showed that height was the most significant predictor and altogether of 5 variables explained the Rrs and Xrs most. Our regression equations at multiple frequencys were comparable to published reference values, especially about the Rrs obtained at 5 Hz. CONCLUSION: IOS is a feasible method to measure the respiratory resistance in untrained children. We got the reference values using IOS and it seems to be useful to diagnose a variety of respiratory diseases.

Effect of the Changing the Lower Limits of Normal and the Interpretative Strategies for Lung Function Tests / 결핵및호흡기질환

BACKGROUND: To interpret lung function tests, it is necessary to determine the lower limits of normal (LLN) and to derive a consensus on the interpretative algorithm. '0.7 of LLN for the FEV1/FVC' was suggested by the COPD International Guideline (GOLD) for defining obstructive disease. A consensus on a new interpretative algorithm was recently achieved by ATS/ERS in 2005. We evaluated the accuracy of '0.7 of LLN for the FEV1/FVC' for diagnosing obstructive diseases, and we also determined the effect of the new algorithm on diagnosing ventilatory defects. METHODS: We obtained the age, gender, height, weight, FEV1, FVC, and FEV1/FVC from 7362 subjects who underwent spirometry in 2005 at the Asan Medical Center, Korea. For diagnosing obstructive diseases, the accuracy of '0.7 of LLN for the FEV1/FVC' was evaluated in reference to the 5th percentile of the LLN. By applying the new algorithm, we determined how many more subjects should have lung volumes testing performed. Evaluation of 1611 patients who had lung volumes testing performed as well as spirometry during the period showed how many more subjects were diagnosed with obstructive diseases according to the new algorithm. RESULTS: 1) The sensitivity of '0.7 of LLN for the FEV1/FVC' for diagnosing obstructive diseases increased according to age, but the specificity was decreased according to age; the positive predictive value decreased, but the negative predictive value increased. 2) By applying the new algorithm, 34.5% (2540/7362) more subjects should have lung volumes testing performed. 3) By applying the new algorithm, 13% (205/1611) more subjects were diagnosed with obstructive diseases; these subjects corresponded to 30% (205/681) of the subjects who had been diagnosed with restrictive diseases by the old interpretative algorithm. CONCLUSION: The sensitivity and specificity of '0.7 of LLN for the FEV1/FVC' for diagnosing obstructive diseases changes according to age. By applying the new interpretative algorithm, it was shown that more subjects should have lung volumes testing performed, and there was a higher probability of being diagnosed with obstructive diseases.

Pulmonary Function and Respiratory Symptoms of Municipal Fire Officers in Busan / 대한산업의학회지

OBJECTIVES: The purpose of this study was to evaluate the relationship between respiratory disorders and fire exposure by investigating and analyzing the lung function and respiratory symptoms of firefighters. METHODS: The health effects of firefighting on respiratory function were investigated in 699 male fire officers in 4 fire departments in Busan by recording respiratory symptoms and measuring lung function. The data were analysed according to fire exposure and smoking habits. RESULTS: Mean spirometric data showed significantly decreased levels in the fire-exposed group (FVC, -0.20 L; FVC%, -4.2%; FEV(1) -0.21 L; FEV(1)%, -5.1%; FEF25%, -0.13 L/SEE p<0.05). After stratification by smoking habits, FVC and FEV(1) showed a significant difference between groups. The prevalence of spirometric abnormality was greater for the fire-exposed group than for the non-exposed group. Significantly higher prevalences of nasal stiffness (16.7% vs. 10.9%), sore throat (17.7% vs.14.2%) and chest tightness (6.5% vs. 2.5%) were recorded in firefighters compared to controls (p<0.05). However, after stratification by smoking habits, the 3 symptoms were showed only marginal differences in the smoking group. CONCLUSIONS: This study demonstrated that fire-exposed firefighters generally suffer a decline of lung function and a higher prevalence of respiratory symptoms. These results suggest that the exposure to routine firefighting activity is associated with adverse health effects to the respiratory system.

Evaluation of pulmonary function and neurophysiological change in patient with chronic obstructive pulmonary disease / 中华物理医学与康复杂志

Objective To explore the association between the lung function and the related electroneurophysiological parameters in patients with chronic obstructive pulmonary disease (COPD). Methods Fifty COPD patients were studied. The lung function and the phrenic motor nerve conduction (PNC) were examined, respectively. Thirty cases of non respiratory disorders served as control. The lung function tests included maximal voluntary ventilation (MVV%), forced vital capacity (FVC), force expiratory volume (FEV 1) and RV/TLC% (residual volume, RV; total lung capacity, TLC). The phrenic nerve was stimulated electrically at the midpoint of the posterior border of the sternomastoid muscle, and the diaphragmatic compound muscle action potential (dCMAP) was recorded between the 7th and 8th intercostal space and xiphoid process. Results The relative values of MVV%, FVC 1/FVC 1% and RV/TLC% were 49.6?18.8, 62.5?16.4 and 54.1?8.0, respectively, which was significantly lower than that expected. There was no significant difference with regard to the PNC latency between the patients and the controls. The dCMAP amplitude ratio in the COPD patients was significantly lower than that of the controls, i.e., the dCMAP amplitude decreased in the COPD patients. Conclusion The decreased dCMAP might be associated with abnormal lung function. The PNC examination would provide valuable information for the evaluation of diaphragmatic dysfunction in those with abnormal lung function.