Refereed review article in scientific journal (A2)
Pulmonary function testing for the diagnosis of asthma in preschool children
List of Authors: Chawes Bo, Elenius Varpu
Publisher: Wolters Kluwer
Publication year: 2022
Journal: Current Opinion in Allergy and Clinical Immunology
Journal name in source: Current opinion in allergy and clinical immunology
Volume number: 22
Issue number: 2
Start page: 101
End page: 106
eISSN: 1473-6322
DOI: http://dx.doi.org/10.1097/ACI.0000000000000815
URL: https://journals.lww.com/co-allergy/Fulltext/2022/04000/Pulmonary_function_testing_for_the_diagnosis_of.8.aspx
Purpose of review
To highlight the recent evidence of the lung function techniques used in preschool children to diagnose asthma.
Recent findings
Several techniques are available to measure lung function and airway inflammation in preschool children, including spirometry (from age 5 years), impulse oscillometry (>3 years), whole-body plethysmography (>3 years), fractional exhaled nitric oxide (FeNO) (>5 years), multiple breath washout (>3 years), structured light plethysmography (>1–2 years) and impedance pneumography (>1 years). If applicable, measuring forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity (FVC) ratio using spirometry is useful (cut-off < 80% predicted or below lower limit of normal [LLN] defined as z-score < −1.64) for diagnosing preschool asthma. For those unable to perform spirometry, whole-body plethysmography (sRaw > 1.6 kPa/s) and impulse oscillometry (Rrs and Xrs at 5 Hz z-score > 2) may be useful. Adding a bronchodilator reversibility test (FEV1 increase > 12%, sRaw decrease > 25–30%, Rrs at 5 Hz decrease > 40%) or a bronchial challenge test, for example, exercise test (FEV1 decrease > 10%), may improve the sensitivity of these tests. Elevated FeNO (>25–35 ppb) is a promising adjunctive test for diagnosing preschool asthma.
Summary
With trained personnel, lung function testing can be done with high reliability even in children between 2 and 4 years of age. To avoid over and undertreatment of asthma, objective measurement of lung function is clinically important in preschool children.