Relative value of various spirometric tests in the early detection of chronic obstructive pulmonary disease

Small airway disease in rheumatoid arthritis

Variety of pulmonary lesions are thought to be associated with rheumatoid arthritis (RA). These lesions traditionally have included pleurisy with or without effusion, Caplan's syndrome, pulmonary rheumatoid nodules, diffuse interstitial fibrosis, and pulmonary arteritis and hypertension. But little attention has been paid to the airways in RA. Recently, several reports have suggested an association between airflow limitation and RA, but its incidence is not known. Also whether there exists a parameter of disease activity of RA, suggesting the presence of small airway disease (SAD) is not clear. To answer these questions, the serologic parameters which reflect the disease activity of RA and pulmonary function tests which reflect small airway dysfunction were performed on 36 lifetime nonsmokers with RA who had normal chest x-ray findings. The prevalence of SAD and the relationships between the disease activity parameters of RA and pulmonary function were observed. The results were as follows. The percentages of patients with abnormal values for diffusing capacity, frequency dependence of compliance (C1.0/C0.0), forced expiratory flow 25-75%, Vmax50% and Vmax 75% were 45.5%, 62.5%, 40%, 22.8% and 11.4%, respectively. There was statistically significant negative correlation between C1.0/C0.0 and ESR. But consistent correlation between other pulmonary function tests and clinical and serologic parameters of RA, and differences in pulmonary function between patients who were serologically positive and negative for CRP and FANA, were not found. In conclusion, SAD, without the influence of smoking, is frequently associated with RA, but the presence of SAD cannot be predicted from any clinical and serologic parameters of RA currently in use.

Spirometry in healthy men: a correlation with smoking and with mild symptoms

Symptoms, smoking history, and variates taken from the forced expiratory manoeuvre were studied in a group of 271 healthy men attending a mass radiography unit. It was found that correlation of the forced expiratory ratio (FEV1/FVC) with the presence of mild or moderate respiratory symptoms was at least as satisfactory as that of technically more complicated measurements such as MEF50 and MEF75. In asymptomatic individuals those differences associated with smoking were the same for FEV1/FVC as for MEF75. Asymptomatic abnormalities of lung function were not observed. Simple measurements such as FEV1/FVC can therefore provide as much information from a forced expiratory manoeuvre to screen for early airways obstruction as MEF50 and MEF75.

Lung function in asthmatic children after year or more without symptoms or treatment

Lung function was examined in 24 children who for a year or more had not received treatment for asthma or had any asthmatic symptoms. Although clinical recovery from asthma was apparent, increased bronchial smooth-muscle tone remained present, which probably renders such children susceptible to obstructive lung disease in adult life. These children should be given guidance on treatment of their symptoms and instructed in preventive measures.

Detection of acute effects of cigarette smoking on airway dynamics: A critical and comparative study of pulmonary function tests

In an effort to determine which measure of airway dynamics was the most sensitive to airway obstruction, comparisons were made between a variety of tests. Twenty cigarette smokers were studied both before and immediately after smoking a cigarette. The maximum midexpiratory flow (FEV25-75) and the FEV1/FVC per cent were abnormal in the largest number of cases. Closing volume was abnormal in only one case. Significant worsening in function after smoking a cigarette occurred in airway resistance and specific conductance. A lesser degree of impairment in airway dynamics was evident from FEV25-75 and first-second expired volume. The closing volume showed no change.