[Irreversible airflow limitation in asthmatics].

To evaluate irreversible airflow limitation in asthmatics, we studied 168 patients admitted to our hospital with acute exacerbation of asthma. All patients were given intravenous methylprednisolone for at least 7 days to maximum 14 days and the best of PEF (% of predicted) was evaluated. In all subjects, the best of PEF showed significant correlations with both the patients' age (r = -0.411, p < 0.0001) and the duration of asthma (r = -0.494, p < 0.0001). A significant correlations between the best of PEF and the duration of asthma were also observed in both patients over 60 years old (r = -0.157, p < 0.0001) and non-smokers (r = -0.568, p < 0.0001). We conclude that asthma may develop irreversible airflow limitation in itself and the degree of impairment of lung function correlated with the duration of the disease.