Respiratory function in healthy young children using forced oscillations

Abstract

Background: Monitoring of respiratory function is important in the diagnosis and management of respiratory disease. The forced oscillation technique requires minimal patient cooperation and is ideal for the determination of respiratory function in young children. This study aimed to develop reference ranges and to document the repeatability in healthy young children using commercially available forced oscillation equipment. Methods: The forced oscillation technique, which uses a pseudo-random noise forcing signal between 4 and 48 Hz, was used to measure respiratory function in healthy young children. Repeatability over a 15 min period was also assessed. Regression equations and standardised Z scores were determined for respiratory resistance (Rrs) and reactance (Xrs) at 6, 8 and 10 Hz. Results: Respiratory function was obtained in 158 healthy children aged two to seven years and between 92 and 127 cm in height. Oscillatory respiratory mechanics exhibited linear relationships with height. Withintest variability for resistance ranged between 6% and 9% and between 17% and 20% for reactance. Resistance and reactance did not change significantly over a 15 min period. Conclusions: Reference ranges for respiratory impedance variables in healthy children aged two to seven years are presented. The short-term repeatability of forced oscillatory variables in this age group is reported, allowing appropriate cut-off values for therapeutic interventions to be defined.

Respiratory impedance and bronchodilator response in healthy Italian preschool children

“…Using the Australian equations 18 to calculate Z-scores for Italian children and comparing then with Z-scores calculated using the Italian equations from the present study showed minor differences for R rs10 (0.23, P ¼ 0.036), X rs8 (0.32, P ¼ 0.012), and X rs10 (0.65, P < 0.001). No significant differences were found for R rs6 (À0.02, P ¼ 0.82), R rs8 (0.10, P ¼ 0.43), and X rs6 (À0.02, P ¼ 0.68).…”

“…The Australian equation was compared to other equations previously published. 18 To date, no assessment of whether these data are applicable to other populations has been published.…”

“…The between-measurement coefficient of repeatability (CR, i.e., twice the standard deviation of the difference between two measurements) for FOT has been reported in healthy children to be between 1.1 and 2.6 hPa s L À1 for respiratory resistance (R rs ) and between 1.2 and 1.7 hPa s L À1 for respiratory reactance (X rs ). [18][19][20] Thamrin et al 10 have shown BDR calculated as a percent change with respect to baseline of À37% for R rs8 and 67% for X rs8 in healthy Australian children. Oostveen et al 14 have reported a decrease in resistance on average of 22% in wheezing children.…”

“…Other reference data sets from large samples of children have been previously published using the pseudorandom noise as the forcing function. 2,[15][16][17][18] Hall et al 18 have previously reported Z rs reference values in a population of Australian preschoolers using a commercially available FOT device that uses a pseudo-random noise as the forcing function. The Australian equation was compared to other equations previously published.…”

Impact of lung disease on respiratory impedance in young children with cystic fibrosis

“…The forced oscillation technique (FOT) is a promising lung function test that can measure the respiratory impedance of the lung in children as young as 2 years of age [17,21,22]. This technique is well suited to measurements in young children as it requires only tidal breathing and minimal cooperation from the child, and can be completed within 5-15 min.…”