Oscillometric and spirometric bronchodilator response in preschool children with and without asthma.
BACKGROUND
Bronchodilator responses (BDR) are routinely used in the diagnosis and management of asthma; however, their acceptability and repeatability have not been evaluated using quality control criteria for preschool children.


OBJECTIVE
To compare conventional spirometry with an impulse oscillometry system (IOS) in healthy and asthmatic preschool children.


METHODS
Data from 30 asthmatic children and 29 controls (two to six years of age) who underwent IOS and spirometry before and after salbutamol administration were analyzed.


RESULTS
Stable asthmatic subjects significantly differed versus controls in their spirometry-assessed BDR (forced expiratory volume in 1 s [FEV1], forced vital capacity and forced expiratory flow at 25% to 75% of forced vital capacity) as well as their IOS-assessed BDR (respiratory resistance at 5 Hz [Rrs5], respiratory reactance at 5 Hz and area under the reactance curve). However, comparisons based on the area under the ROC curve for &Delta;FEV1 %initial versus &Delta;Rrs5 % initial were 0.82 (95% CI 0.71 to 0.93) and 0.75 (95% CI 0.62 to 0.87), respectively. Moreover, the sensitivity and specificity for &Delta;FEV1 >=9% were 0.53 and 0.93, respectively. Importantly, sensitivity increased to 0.63 when either &Delta;FEV1 >=9% or &Delta;Rrs5 >=29% was considered as an additional criterion for the diagnosis of asthma.


CONCLUSIONS
The accuracy of asthma diagnosis in preschool children may be increased by combining spirometry with IOS when measuring BDR.
Department of Pediatrics, CHA University School of Medicine, Seongnam, Republic of Korea.
Youn Ho
YH
Shin
Sun Jung
SJ
Jang
Jung Won
JW
Yoon
Hye Mi
HM
Jee
Sun Hee
SH
Choi
Hye Yung
HY
Yum
Man Yong
MY
Han
D000403:Airway Resistance; D000420:Albuterol; D001249:Asthma / Q000175:diagnosis*; D001993:Bronchodilator Agents; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D009991:Oscillometry; D012372:ROC Curve; D012680:Sensitivity and Specificity; D013147:Spirometry
D001993:Bronchodilator Agents; D000420:Albuterol