Proximal airway function 8 to 16 years after laryngomalacia: follow-up using flow-volume loop studies.

Twenty children who had endoscopically confirmed laryngomalacia were reviewed at 8 to 16 years of age. All had developed stridor in the first 6 weeks of life; stridor had stopped or largely resolved by age 4 years. Proximal airway function was assessed by expiratory and inspiratory flow volume loops and compared with control values. These children as a group had variable extrathoracic obstruction to inspiratory airflow, as indicated by a significantly low maximal inspiratory flow at 50% of vital capacity and a high mean ratio of maximal expiratory to maximal inspiratory flow at 50% vital capacity. Although limitation to inspiratory airflow was detectable in later childhood, it was not associated with troublesome symptoms. Significant stridor always resolved by 4 years of age, but some children experienced minor stridor under stress in later childhood.