Correlación entre la espirometría y la resistencia y reactancia respiratoria medida por oscilometría de impulso en niños asmáticos

Abstract

Impulse oscillometry (IOS) is a technique that measures respiratory resistance (Rrs) and reactance (Xrs) at several frequencies, through the interpretation of oscillatory impulses overlapping spontaneous breathing. It is a non-invasive, fast and easy to perform technique that requires minimal patient cooperation. Three of the most sensitive parameters to evaluate peripheral airways obstruction are resistance and reactance at 5 Hertz (Rrs5 and Xrs5), and resonance frequency (RF). The aim of this study was to evaluate the correlation between spirometry and IOS, in asthmatic children. Spirometry and IOS using a Jaeger Masterscreen IOS equipment, were performed in asthmatic children > 6 years old, during a six month period. Only the tests that fulfilled the international criteria of acceptability and reproducibility were used for the study. 98 acceptable tests for both techniques were obtained, in 40 girls and 58 boys of 9.3 y.o. in average (range: 6 to 15 y.o.). FEV1, FEF 25-75, FEF25, FEF50 and FEF75 were correlated with Rrs5, Xrs5, and RF. Correlation coefficients ranged from r = 0.5 to 0.73 (p < 0.005 in all correlations). The best correlation obtained was between Rrs5 and FEV1 (r = 0.73) and between Rrs5 and FEF25. (r = 0.7). In conclusion, we found a good correlation between spirometry and IOS in this series of 98 asthmatic children. The best correlations obtained were between Rrs5 and FEV1 and between Rrs5 and FEF25.