The role of bronchial challenge test in guiding therapy in preschool
children with atypical recurrent respiratory symptoms
Abstract
Objective: This retrospective observational cohort study aimed
to assess the real-life application of bronchial challenge test (BCT) in
the management of preschool children presenting with atypical recurrent
respiratory symptoms (ARRS). Methods: We included children,
aged 0.5-6 years referred to a pediatric-pulmonology clinic, who
underwent BCT using methacholine or adenosine between 2012-2018 due to
ARRS including uncertain severity of airway hyperactivity. BCT was
considered positive based on spirometry results and/or wheezing,
desaturation, and tachypnea reactions. We collected data on
demographics, BCT results, pre-BCT treatment, post-BCT treatment change
and post-BCT symptoms control. The primary outcome measure was the
change in treatment post-BCT (step-up or step-down). Secondary outcome
included clinical improvement observed 3-6 months after BCT.
Results: A total of 228 children (55% males) with a mean age
of 4.2±0.6 years underwent BCT (52% adenosine-BCT, 48%
methacholine-BCT). Children referred for methacholine were significantly
younger compared to adenosine (3.6±1.2 vs. 4.2±1.2 years,
P<0.01). Methacholine and adenosine BCTs were positive in 95%
and 61%, respectively. Overall, changes in management were observed in
122(53.5%) children following BCT, with 83(36.4%) being stepped up and
37(17%) being stepped down. Significantly more children in the
methacholine group were stepped up compared to the adenosine (46% vs
28%, p=0.004). During the follow-up assessment, we observed a clinical
improvement in 119/162 (73.4%) of the children. Conclusion:
This study demonstrates the importance of BCT in the management of
preschool children presenting to pediatric pulmonary-units with ARRS.
The change in treatment and subsequent clinical improvement observed,
highlight the added-value of BCT in this populations.