The interrupter technique is a convenient and sensitive technique for studying airway function in subjects who cannot actively participate in (forced) ventilatory function tests. Reference values for preschool children exist but are lacking for children > 7 yrs. Reference values were obtained for expiratory interrupter resistance (Rint,e) in 208 healthy Dutch Caucasian children 3-13 yrs of age. A curvilinear relationship between Rint,e and height was observed, similar to published airways resistance data measured by plethysmography. No significant differences in cross-sectional trend or level of Rint,e were observed according to sex. It was found that Z-scores could be used to express individual Rint,e values and to describe intra- and interindividual differences based on the reference equation: 10logRint,e = 0.645 - 0.00668 × standing height (cm) kPa.L-1.s-1 and residual SD (0.093 kPa.L-1.s-1). Expiratory interrupter resistance provides a tool for clinical and epidemiological assessment of airway function in a large age range.

Children, Interrupter technique, Lung function test, Reference values,
The European Respiratory Journal
Department of Pediatric Surgery

Merkus, P.J.F.M, Arets, H.G, Joosten, K.F.M, Siero, A, Brouha, M, Mijnsbergen, J.Y, … van der Ent, C.K. (2002). Measurements of interrupter resistance: Reference values for children 3-13 yrs of age. The European Respiratory Journal, 20(4), 907–911. doi:10.1183/09031936.02.01262001