Pulmonary function in children: II. Preliminary studies in chronic intractable childhood asthma

Abstract

1. 1. Complete lung volume and ventilatory studies have been made in a group of fourteen inpatient asthmatic children shortly after admission to the hospital and at varying times after treatment in the hospital. 2. 2. Abnormalities in lung volumes, maximum breathing capacity, and timed vital capacity, alone or in combination, were noted in the majority of these children. Improvement in clinical status was not always accompanied by improvement in pulmonary function measurements. 3. 3. The one-second timed vital capacity determination alone did not appear to be a reliable predictor of pulmonary function in this study. Furthermore, there was very little correlation between the one-second timed vital capacity and the maximum breathing capacity. 4. 4. The functional residual capacity, the total lung capacity, and the FRC/TLC ratio proved to be useful indices of hyperinflation in this group of asthmatic children. 5. 5. The helium-mixing curve was used as an index of distribution of inspired gas. Prolongation of helium equilibration was discovered in two children who were thought to have emphysema on evidence of combined clinical x-ray and pulmonary function evaluations. 6. 6. Pulmonary function measurements will provide the clinician with objective criteria of prognosis and response to treatment in childhood asthma.