Objectives:This study was conducted to evaluate the ventilatory function in shipyard welders using the lifetime cumulative exposure to welding fumes. METHODS: Ventilatory function tests were performed on 241 male welders at one large shipyard,exposed to welding fumes for over five years,and was compared to 80 male control subjects. Ventilatory function indices, such as forced vital capacity(FVC), one-second forced expiratory volume(FEV 1), ratio of FEV 1 to FVC(FEV 1%), maximal mid-expiratory flow(MMF), peak expiratory flow rate(PEFR)and maximal expiratory flow at 50 and 75% of expired FVC(FEF50 and FEF75), were obtained by analyzing forced expiratory spirograms and maximal expiratory flow-volume curves that were simultaneously measured by an Impulse ocillometry(IOS)program in the standing position. RESULTS: FEF50 and FEF75 expressed as a percentage of the predicted values were significantly lower in the exposure group than in the controls, and the MMF tended to decrease.The means of all the ventilatory indices,expressed as percentage of the predicted values, were not significantly increased at the current exposure levels. The MMF, FEF50 and FEF75, expressed as a percentage of the predicted values, were significantly decreased with an increase in exposure duration.Only the FEF75 , expressed as a percentage of the predicted value, was significantly decreased with an increase in the cumulativeexposure to welding fumes(C1). The FEF75, expressed as a percentage of the predicted value, was significantly decreased with an increase in the cumulative exposure to welding fumes(C2). The above parameters were calculated to consider the current exposure level, exposure duration, application of the ventilatory system, production rate, personal protection evice, electrode and welding wire. The MMF and FEF50, expressed as a percentage of the predicted value, tended to decrease. The proportion of workers with abnormal MMF, FEF50 and FEF75 were significantly increased with an increase in the cumulative exposure to welding fumes(C2). CONCLUSIONS: These findings suggested that the MMF, FEF50 and FEF75 are sensitive and practical indices for the evaluation of the ventilatory function of workers exposed to welding fumes, when the lifetime cumulative exposure(C2) is considered as a factor affecting exposure.
Electrodes ; Humans ; Male ; Maximal Expiratory Flow-Volume Curves ; Welding*

OBJECTIVES: The shape of the flow-volume (F-V) curve is known to change to showing a prominent plateau as stenosis progresses in patients with tracheal stenosis. However, no study has evaluated changes in the F-V curve according to the degree of bronchial stenosis in patients with unilateral main bronchial stenosis. METHODS: We performed an analysis of F-V curves in 29 patients with unilateral bronchial stenosis with the aid of a graphic digitizer between January 2005 and December 2011. RESULTS: The primary diseases causing unilateral main bronchial stenosis were endobronchial tuberculosis (86%), followed by benign bronchial tumor (10%), and carcinoid (3%). All unilateral main bronchial stenoses were classified into one of five grades (I, < or =25%; II, 26%-50%; III, 51%-75%; IV, 76%-90%; V, >90% to near-complete obstruction without ipsilateral lung collapse). A monophasic F-V curve was observed in patients with grade I stenosis and biphasic curves were observed for grade II-IV stenosis. Both monophasic (81%) and biphasic shapes (18%) were observed in grade V stenosis. After standardization of the biphasic shape of the F-V curve, the breakpoints of the biphasic curve moved in the direction of high volume (x-axis) and low flow (y-axis) according to the progression of stenosis. CONCLUSION: In unilateral bronchial stenosis, a biphasic F-V curve appeared when bronchial stenosis was >25% and disappeared when obstruction was near complete. In addition, the breakpoint moved in the direction of high volume and low flow with the progression of stenosis.
Bronchi ; Carcinoid Tumor ; Constriction, Pathologic* ; Humans ; Lung ; Maximal Expiratory Flow-Volume Curves ; Spirometry ; Tracheal Stenosis ; Tuberculosis

BACKGROUND: For the diagnosis or evaluation of airway obstruction in bronchial asthma and chronic obstructive lung disorders, various parameters derived from the forced expiratory volume curve and maximal expiratory flow volume cutie have been used. Recently the peak expiratory flow(PEF) measured by the peak flow meter is widely used because of its simplicity and convenience. But there were still no data of the predicted normal values measured by the peak flow meter in Korea. This study was to obtain the predicted normal value of PEF and to know the accuracy of this value 18 predict FEV1. METHOD: The measurements of PEF by the MiniWright peak flow meter and several parameters derived from the forced expiratory volume and maximal expiratory flow volume curves by the Microspiro HI 501(Chest Co.) were done in 129 men and 125 women without previous history of the respiratory diseases. The predicted normal values of parameters according tc the age and the height were obtained, and the regression equation of FEV1 by PEF was calculated. RESULTS: The predicted normal values of PEF(L/min) were 2.45 Age(year)+1.36 Height(cm)+427 in men and -0.96 Age(year)+2.01 Height(cm)+129 in women. FEFmax derived from the maximal expiratory flow volume cutie was less than by 125 L/min in men art 118 L/min in women respectively compared to PEF. FEV,(ml) predicted by PEF was 5.98 PEF(L/min) 303 in men and 4.61 PEF(L/min) 291 in women respectively. CONCLUSION: The predicted normal value of PEF measured by the peak flow meter was calculated and it could be used as a standard value of PEF while taking care of patients with airway obstruction FEV1, the gold standard of ventilatory function could be predicted by PEF to a certain extent.
Airway Obstruction ; Asthma ; Diagnosis ; Female ; Forced Expiratory Volume ; Humans ; Korea ; Lung ; Male ; Maximal Expiratory Flow-Volume Curves ; Reference Values

OBJECTIVETo assess the quality control for the maximal expiratory flow-volume (MEFV) curve in school-age children.

METHODSEight hundred and sixty-two children who had two or more MEFV manoeuvres were classified into ≥6-year-old (n=379), ≥8-year-old (n=210), ≥10-year-old (n=64), and 12-17-year-old groups (n=109). The parameters of quality control and concordance with quality control criteria for MEFV were compared between the two groups. In addition, patients who were diagnosed with asthma were classified into two groups, one with normal pulmonary function (n=155) and the other with abnormal pulmonary function (n=62), based on the results of spirometry. Differences in the parameters of quality control for spirometry were compared between the two groups.

RESULTSEight hundred and sixty-two children underwent 2 367 MEFV manoeuvres, 97.8% of which met the start of test criterion for backward extrapolated volume (VBE) of less than 0.15 L, with the highest concordance in the ≥6-year-old group and the lowest concordance in the 12-17-year-old group. Three hundred and eighty-one children (44.2%) met the end of test criterion for forced expiratory time (FET) and the concordance in children over 10 years of age was lower than that in children under 10 years of age (P<0.05). Differences in two best forced expiratory volume in first second (FEV1) and forced vital capacity (FVC) manoeuvres were within 150 mL in 91.9% and 84.8%, respectively, of the children. The parameters of quality control for spirometry were better for asthmatic children with abnormal pulmonary function compared with asthmatic children with normal pulmonary function (P<0.05).

CONCLUSIONSConcordance with the start of test criteria and the manoeuvre repeatability criteria is high, whereas the concordance with the end of test criteria is low. It is suggested that the concordance with the FET criteria should be improved.

Adolescent ; Age Factors ; Child ; Female ; Forced Expiratory Volume ; Humans ; Male ; Maximal Expiratory Flow-Volume Curves ; Quality Control

Asthma ; physiopathology ; Child ; Female ; Humans ; Male ; Maximal Expiratory Flow-Volume Curves ; Oscillometry ; methods ; Pulmonary Disease, Chronic Obstructive ; physiopathology ; Respiratory Function Tests