Text Box: THE APPLICABILITY OF IMPULSE OSCILLOMETRY IN DETERMINATION OF PULMONARY FUNCTIONFOR CHILDREN WITH ASTHMA Wang LB, Li YZ, Zhang H, et al Children¡¯s Hospital of Fu Dan University, Shanghai, China Objective: To compare the correlation between impulse oscillometry (IOS) data and spirometric parameters obtained from regular pulmonary function measurement in group of children with asthma, and to search the clinical value of IOS in evaluation for children with asthma. Methods: The impedance of respiratory system was measured by IOS in 39 children with asthma, aged from 4 to 12 years, and the relationship of IOS data to spirometric parameters was evaluated. The IOS data include resistance in 5Hz(R5), resistance in 20Hz(R20), difference between R5 and R20 (R5-R20), resonant frequency (Fres) and reactance at 5Hz(X5). Result: Fres, R5 and R5-R20 was markedly negative correlated with FEV1%, FEV1%, Vcmax, FEF25%, FEF50%, FEF75% (varying from r=-0.344, p<0.05 to r=-0.797, p<0.01). X5 was positive correlated with spirometric parameters (varying from r=0.407, p<0.05 to r=0.695, p<0.01). But no correlation between R20 and spirometric parameters reached a statistically significance. The closer correlation was found between Fres, R5-R20 and FEV1%. The correlation coefficient values were ¨C0.726 between Fres and FEV1%, and ¨C0.797 between R5-R20 and FEV1%. Fres, R5 and R5-R20 were more increased in severe asthma with FEV1%<60% than in middle asthma with FEV1% 60~80% and mild asthma with FEV1%>80%. Conclusion: Fres and R5-R20 were the most sensitive index of IOS parameters for evaluating pulmonary function of children asthma and objective parameters reflecting clinical degree of children asthma. 1199