Airway resistance in children measured using the interrupter technique: reference values.
OBJECTIVE
The interrupter technique is used for determining interrupter resistance (Rint) during quiet breathing. This noninvasive method requires minimal cooperation and can therefore be useful in evaluating airway obstruction in uncooperative children. To date, no reference values have been determined for Rint in a Brazilian population. The objective of this study was to define a prediction equation for airway resistance using the interrupter technique for healthy children aged 3-13 years.


METHODS
This was a prospective, cross-sectional study involving preschool and school children in Porto Alegre, Brazil, in whom Rint was measured during peak expiratory flow.


RESULTS
One-hundred and ninety-three children were evaluated. Univariate analysis using linear regression showed that height, weight and age correlated significantly and independently with Rint. Multiple regression with height, weight, age and gender as variables resulted in a model in which only height and weight were significant, independent predictors of Rint. Collinearity was identified among height, weight and age.


CONCLUSIONS
Reference values and an equation for calculating Rint in healthy children were obtained and are adjusted for height.
Rech
Viviane Viegas
VV
Universidade Luterana do Brasil, Canoas, RS, Brasil.
Vidal
Paula Cristina Vasconcellos
PC
Melo Júnior
Hilário Teixeira de
HT
Stein
Renato Tetelbom
RT
Pitrez
Paulo Márcio Condessa
PM
Jones
Marcus Herbert
MH
D000293:Adolescent; D000402:Airway Obstruction / Q000473:pathology; D000403:Airway Resistance / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D011446:Prospective Studies; D012016:Reference Values; D012129:Respiratory Function Tests / Q000379:methods*