Usefulness of modified Pulmonary Index Score (mPIS) as a quantitative tool for the evaluation of severe acute exacerbation in asthmatic children

Abstract

Abstract Background Acute exacerbation of asthma is divided qualitatively into mild, moderate, and severe attacks and respiratory failure. This system is, however, not suitable for estimating small changes in respiratory condition with time and for determining the efficacy of treatments, because it has a qualitative, but not quantitative nature. Methods To evaluate the usefulness of quantitative estimation of asthma exacerbation, modified Pulmonary Index Score (mPIS) values were measured in 87 asthmatic children (mean age, 5.0 ± 0.4 years) during hospitalization. mPIS was calculated by adding the sum of scores for 6 items (scores of 0-3 were given for each item). These consisted of heart rate, respiratory rate, accessory muscle use, inspiratory-to-expiratory flow ratio, degree of wheezing, and oxygen saturation in room air. Measurements were made at visits and at hospitalization and were then made twice a day until discharge. Results mPIS values were highly correlated among raters. mPIS values at visits were 9.1 ± 0.1 and 12.6 ± 0.4 in subjects with moderate and severe attacks, respectively (p < 0.001). mPIS values of subjects requiring continuous inhalation therapy (CIT) with isoproterenol in addition to systemic steroids were significantly higher than the values of those without CIT (12.0 ± 0.5 and 9.3 ± 0.2, respectively, p < 0.001). A score of 10 was suggested to be the optimal cutoff for distinguishing between subjects requiring and not requiring CIT, from the perspectives of both sensitivity and specificity. mPIS at hospitalization correlated well with the period until discharge, suggesting that this score was a useful predictor for the clinical course after hospitalization. Conclusions mPIS could be a useful tool for several aspects during acute asthma attacks, including the determination of a treatment plan, and prediction of the period of hospitalization in admitted patients, although prospective studies would be required to establish our hypothesis.