Occult pulmonary abnormalities in asymptomatic asthmatic children

Chest. 1977 Mar;71(3):361-5. doi: 10.1378/chest.71.3.361.


The pulmonary status of 178 asymptomatic asthmatic children with normal time-volume spirograms was further evaluated using flow-volume loops, body plethysmographic studies, and blood gas tensions in arterialized capillary blood. Residual volume (RV) was abnormal in 26%, total lung capacity (TLC) in 33%, RV/TLC% in 41%, and arterial oxygen pressure in 23% of them. All values for expiratory flow measured relative to observed vital capacity (VC), (ie, the forced expiratory volume in one second [FEV1], the mean forced expiratory flow during the middle half of the forced vital capacity [FEF25-75%; FVC], FEV1/VC, and the instantaneous forced expiratory flow after 75% and after 50% of the FVC has been exhaled) were normal, and VC was subnormal in only five instances, but flow rates measured relative to TLC were abnormal in 26% of the patients. Some abnormality of pulmonary function was present in all but 13% of these asymptomatic children. Reliance upon conventional evaluation of pulmonary function by forced expiratory spirograms and freedom from wheezing may frequently give the clinician a false impression of the true conditon of the lungs of the asthmatic child.

MeSH terms

  • Adolescent
  • Asthma / physiopathology*
  • Child
  • Child, Preschool
  • Female
  • Forced Expiratory Volume
  • Humans
  • Male
  • Maximal Expiratory Flow-Volume Curves
  • Residual Volume
  • Respiration*
  • Total Lung Capacity
  • Vital Capacity