Lung function measurements in children - copsac

Summary
The Ph.D. thesis is based on studies conducted at 6 pediatric departments in following
hospitals: Næstved, Gentofte, Kolding, Skejby, Hvidovre and Rigshospitalet.
Study I: Specific airway resistance (sRaw) measured by wholebody plethysmography in
preschool children is increasingly used in research and clinical practise. However, there
is no available method for calibration of the resistance measure, which raises concern of
accuracy.
The primary aim was to determine the agreement of sRaw measurements in 6 centers.
Seven healthy young children were brought to each of the 6 centers for sRaw
measurements and measured by a center specific investigator as well as an investigator
visiting each center.
We found sRaw measurements at two centers were significantly lower in all children
compared to the other 4 centers and one center had significantly higher sRaw values
than the other centers.
The secondary aim was to expand normative sRaw values for non-asthmatic children in
5 centers. 105 healthy preschool children were recruited locally for sRaw
measurements. Normative data was generated and was without significant difference
between centers and independent of height, weight, age and gender. Furthermore, there
was no effect of the child’s history of atopy, parental atopy or smoking. We
subsequently pooled these normative data (105 children) with previous data from 121
healthy young children; mean sRaw (SD) 1.27 kPa*s (0.25).
Conclusion: Control using biological standards revealed errors in factory setting and
highlights the need for developing methods for verification of resistance measures to
assure accuracy. Normative data were subsequently generated. Importantly other centers
using such normative data should first consider proper calibration before applying
reference values.
Study II-III: Acute respiratory syncytial virus (RSV) bronchiolitis may occur in
otherwise healthy infants. It is not known whether viral bronchiolitis is causatively
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