Analysis of Breathing Pattern in Children with Asthma

The breathing pattern in children with asthma was studied, using respiratory inductive plethysmography. The subjects were 31 children with mild to moderate asthma (15 males, 16 females; aged 6∼15 years, average 11 years). The respiratory rate was 25.5±10.7/min. (mean ± S.D.) during asthma attacks and 18.4 ± 5.0/min. between attacks with a significant increase during attacks (P < 0.001). The expiratory time was 1.774 ± 0.833 second during attacks, and 2.125 ± 0.602 seconds between attacks. The expiratory time to total respiratory time ratio (T_E/T_TOT) was 0.631 ± 0.056 during attacks and 0.608 ± 0.035 between attacks. Thus there was a slight prolongation at the time of attack, but the difference was not significant. The tidal volume was increased slightly during mild and moderate attacks. V_T/T_I (mean inspiratory flow) was increased during attacks. The respiratory pattern was thoracic during attacks and changed to the abdominal pattern with improvement.