THE CAPACITY OF CHILDREN WITH AND WITHOUT ASTHMA TO DETECT EXTERNAL RESISTIVE LOADS ON BREATHING

Clinical observations and research with adults consistently showed tha t subjective symptoms of asthma poorly reflect actual airway obstructi on. The lack of accurate symptom perception poses a problem for medica tion and management of asthma. The accuracy of airflow detection was s tudied in 46 children with and 46 without asthma (aged 7-18 years). Th ey breathed through a facemask and responded to load stimuli of differ ent intensity. Sessions consisted of 10 blocks of 5 min, each with 10 stimuli presented. Experiment 1: Loads of increasing intensity present ed to 36 children with and 36 without asthma. Seven asthmatics had a r eliable detection threshold (just noticeable difference, jnd) analogou s to approximate to 64% fall in forced expiratory volume in 1 sec (FEV (1)). Ten normal controls had a jnd of approximate to 39% fall. Experi ment 2: Loads randomly presented to 10 children with and 10 without as thma. Four asthmatics had a jnd of approximate to 64% fall in FEV(1). Six normal controls had a jnd of approximate to 39% fall. The results demonstrated that children generally were poorly perceiving load stimu li and that asthmatics were less accurate.