By Bent Helmuth Klug, MD, DMSci
Chairman: Niels Henrik Valerius
Opponent: Peter Oluf Schiøtz
Opponent: Jann Mortensen
Airway diseases giving rise to recurrent or chronic respiratory symptoms are common in infants and young children (Beasley, R. et al, 2000). Assessment of respiratory function by objective measurements is essential to the understanding of respiratory function in health and disease, and several techniques have been standardized for use in adults and school-age children (Quanjer, P H. et al, 1993). The lung function techniques routinely applied in adults and schoolchildren require considerable active co-operation by the subject who must perform a maximal inspiration followed by forceful expiration (Quanjer; P. H. et al, 1993). This manoeuvre is rarely performed sufficiently by young children. Therefore, measurements of the expired volume in the first second (FEV1) and the forced vital capacity (PVC) are considered unreliable in young children (Kanengiser, S. and Dozor, A. J. 1994). During the last decade a number of techniques for measurement of lung function in infants have been extensively investigated and some techniques have become standardized (ATS/ERS workshop summary, 1993). However, these techniques usually require that the subject is sedated and the measurement procedures are not directly applicable in young children. This leaves a gap with respect to techniques applicable for testing of lung function in 2-6 year old children. Lung function testing in this age-group constitutes a particular challenge which must consider both the physiological and the psychological characteristics of young children (NHLBI workshop summary, 1993; Tepper, R. and Sly, P 1996). During the last 20 years encouraging results have been achieved by a variety of non-invasive techniques which require passive co-operation only. However, so far most studies have been performed in older children and few data are available from studies documenting the use of these techniques in 2-6 year old children. The present research project was undetaken to investigate different techniques potentially applicable for measurement of lung function in children 2-6 years of age.