Pulmonary Function of Different Categories of Chronic Obstructive Pulmonary Diseases in Railway Workers of Eastern India

Pulmonary function tests were done on 146 established chronic obstructive pulmonary disease (COPD) patients and 151 normal non-smoker and smoker subjects. These patients were assembled from Garden Reach Railway Hospital (Calcutta), West Bengal, India, 79 of which suffered from chronic bronchitis, 8 from chronic bronchitis with mild emphysema (who were included in the chronic bronchitis group), 38 from emphysema and 21 from asthma. In the normal subjects 75 were non-smokers and 76 smokers. All the subjects were in the age range of 16－60 years. The mean values obtained in COPD patients were compared with those of normal non-smokers and smokers in each group and amongst the different categories of COPD patients. All the pulmonary function tests (PFT) were measured by the standard spirometric technique, and the Peak Expiratory Flow Rate (PEFR) was studied by Wright's Peak Flow Meter. The values were expressed in body temperature at ambient pressure saturated with Water Vapour Pressure (BTPS). The PFT values significantly deteriorated in all categories of COPD patients as compared to normal non-smokers and smokers, but a few parameters showed exceptions. Significant deterioration was observed in emphysematous patients when compared to other categories of COPD patients. No definite trend of reduction of pulmonary function test values were found according to the years of suffering from the disease. A product moment correlation matrix showed a highly significant positive correlation between FVC and FEV1, in all four groups of patients. These two parameters also showed a strong positive relationship with FEF25－75%, EFF200－1200ml, FEF75－85%, MVVF and PEFR. The regression equations for some of the closely related variables of high correlation coefficient were calculated in COPD patients and presented.