Assessment of Airway Bronchodilation by Spirometry Compared to Airway Obstruction in Young Children with Asthma

Abstract

A reversibility test by an increase of greater than 12% in FEV1 can support a diagnosis of asthma and alter a patient's treatment plan but may not be applicable to the young ages. We retrospectively gathered spirometric data from 85/271 asthmatic children having mild obstruction (FEV1 > 80% predicted), age 2.6–6.9 years. Spirometry was performed before and 20 min after inhalation of 200 mcg Albuterol. We defined a deviation below −1.64 z scores from control as obstruction and an increased above 1.64 scores from control as a positive response to bronchodilators. Sensitivity of the index was considered significant if it captured >68% of the participants. The sensitivity of detecting airway obstruction in these children by FEV1 was 15.3% and 62.4% by FEF25–75. A positive response to Albuterol was an increase of 9.2% for FEV1 (12% for adults) and 18.5% for FEF25–75. The sensitivity for detecting a response to Albuterol in mild asthma was 64.7% by FEV1 and 91.8% by FEF25–75. Young children having normal spirometry can demonstrate airway reversibility. The response of spirometry parameters to bronchodilators may be more sensitive than obstruction detection and may help to support the diagnosis of asthma and adjust treatment plan.

Forced Expiratory Flow (FEF25–75%) as a Clinical Endpoint in Children and Adolescents with Symptomatic Asthma Receiving Tiotropium: A Post Hoc Analysis

“…However, it should be noted that tiotropium, as a bronchodilator, may have other mechanisms of action affecting small as well as large airways, although there is currently no evidence of this. A previous study using a different bronchodilator, albuterol, with an alternative delivery device (pressurized metered dose inhaler), provided results in accordance with those reported here, further supporting the utility of FEF 25-75% as a more sensitive measure of airway response to bronchodilators than FEV 1 in children and adolescents with asthma, irrespective of delivery device [4].…”

“…Forced expiratory flow at 25-75% of the vital capacity (FEF 25-75% ) is potentially a more sensitive parameter than FEV 1 for assessing changes in peripheral airway function in pediatric patients [2,3]. Indeed, Vilozni et al reported that FEF 25-75% was a more numerically sensitive index than FEV 1 in detecting airway obstruction and response to bronchodilators [4]. However, current data on the value of FEF 25-75% compared with FEV 1 are limited.…”

Approaches to Asthma Diagnosis in Children and Adults

“…However, correct technique must be ensured, and this relies on patient cooperation and adherence in undertaking the measurements (45). Demonstration of improvement in spirometry following bronchodilator may be more sensitive in children than detection of obstruction (46). Demonstration of reversibility after bronchodilator had good specificity for an asthma diagnosis (73%), but using a cut-off of 12% improvement for children carried poor diagnostic sensitivity (35%), while a cut-off of 8% was significantly better (47).…”

Variation in spirometry parameters in children with and without recurrent respiratory problems

“…This was explained by the fact that these children were on inhaled corticosteroids which could have led to a decrease in reversibility nearing that of control subjects 35 . Other studies have found that FEF 25-75 is a better marker to assess bronchodilator reversibility than FEV 1 [36][37][38] . In our study, although the median value of FEF 25-75 reversibility seems higher on gross comparison to FEV 1, a detailed comparison between the two was beyond the scope of this study.…”