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

Abstract

IntroductionImpulse 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.ObjectiveThis study aimed to determine the IOS reference values and bronchodilator response in healthy preschool children living in Bogotá, Colombia.MethodsWe 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.ResultsValues 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.ConclusionsNormal 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.

Reference values for respiratory sinusoidal oscillometry in children aged 3 to 17 years

“…The selection of healthy children with strict eligibility, combined with stringent criteria for data acquisition and quality control, large height spectrum, and use GAMLSS models, may have all contributed to the excellent fit of our data. In line with others, 39,41 we did not succeed in enrolling children aged 2 years in whom the use of a mask rather than mouthpiece may be more applicable. As for most reference values, 18,20,31 we reported few children less than 100 cm (n < 10) and advice caution in the interpretation of values in the smallest children.…”

Assessment of a bronchodilator response in preschoolers: a systematic review

“…Twenty-two studies (51.2%) calculated a BDR cut-off based on a healthy control group (Table 2) 1,8,15,19,20,25,28,30–32,35,38–40,43,45,47–52 . BDR %INIT was reported by all studies except Malmberg et al 2003 for IOS outcomes and Nielsen et al 2001 for sRaw (Figure 3).…”

Lung Function in Preschool Children in Low and Middle Income Countries: An Under-Represented Potential Tool to Strengthen Child Health

“…Reference data for Mexican, Thai, Turkish and Colombian children have been collected ( 70 – 72 , 75 – 77 ), facilitating the use in diagnosis of respiratory disease. It is also a useful tool to assess airway reversibility in asthmatic children and cut off values for bronchodilator response were proposed ( 69 , 73 ).…”