Impulse oscillometry reference values and bronchodilator response in three- to five-year old children living at high altitude

Abstract

Elida Duenas-Meza,1 Eliana Correa,1 Eliana López,2 Juan Carlos Morales,2 Carlos Eduardo Aguirre-Franco,1 Carlos Fabián Morantes-Ariza,3 Carlos Eduardo Granados,2 Mauricio González-García1 1Fundación Neumológica Colombiana, Bogotá, Colombia; 2Universidad De La Sabana, Chía, Colombia; 3Universidad Nacional De Colombia, Bogotá, ColombiaCorrespondence: Elida Duenas-MezaFundación Neumológica Colombiana, Bogotá 110131, ColombiaTel [phone]Fax [phone]Email [email protected]: Impulse oscillometry (IOS) is used to measure airway impedance. It is an effective tool for diagnosing and treating respiratory diseases, and it has the advantage that it does not require forced respiratory maneuvers. IOS reference values are required for each population group.Objective: This study aimed to determine the IOS reference values and bronchodilator response in healthy preschool children living in Bogotá, Colombia.Methods: We performed a cross-sectional study in preschool children who had no history of respiratory disease; 96 children fit the parameters for testing to determine normal values according to the American Thoracic Society and European Respiratory Society criteria.Results: Values for respiratory resistance (Rrs) and reactance (Xrs) at 5, 10, and 20 Hz, respiratory impedance (Zrs, and resonance frequency (Fres) were established. Height was the most influential independent variable for IOS values; an increase in height led to a reduction in Rrs5 and Rrs20 and an increase in Xrs5. After the administration of 400 mcg of salbutamol the values for Rrs5(−17.48%), Rrs20(−8.63%), Fres (−10.68%), and area of reactance (−35.44%) were reduced, meanwhile Xrs5 (15.35%) was increased.Conclusions: Normal IOS values before and after the administration of 400 mcg of salbutamol were determined for a population of children aged 3–5 years at 2,640 m. Reference IOS equations for these children are presented. A relative change of up to −28% and 36% after the use of salbutamol for respiratory resistance and reactance, respectively, should be considered as an upper limit of the normal range, and possible appropriate cut-off values for defining significant response for evaluating therapeutic interventions.Keywords: oscillometry, children, reference values, high altitude, respiratory function tests, cross-sectional studies

Keywords

• Oscillometry
• Children
• Reference Values
• High Altitude
• Respiratory function tests
• Cross-Sectional Studies.