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Interrupter technique for evaluation of exercise‐induced bronchospasm in children
Author(s) -
Kannisto Senja,
Vanninen Esko,
Remes Kyllikki,
Korppi Matti
Publication year - 1999
Publication title -
pediatric pulmonology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.866
H-Index - 106
eISSN - 1099-0496
pISSN - 8755-6863
DOI - 10.1002/(sici)1099-0496(199903)27:3<203::aid-ppul9>3.0.co;2-g
Subject(s) - medicine , bronchospasm , interrupter , spirometry , asthma , pulmonary function testing , airway resistance , repeatability , peak flow meter , bronchoconstriction , lung volumes , physical therapy , cardiology , lung , chemistry , chromatography , physics , quantum mechanics
The free running test is a useful method for evaluation of exercise‐induced bronchospasm in children. In young children this test simulates real‐life circumstances and can be done more easily than histamine or methacholine challenges. The interrupter technique is a noninvasive method for measuring airflow resistance during tidal breathing. This approach requires minimal cooperation, and is therefore promising for use in young children. Fifty children aged 5–15 years with asthma symptoms were tested by exercise challenge consisting of free outdoor running for 8 min at 85% of maximal predicted heart rate for age. Pulmonary function was measured by using the interrupter technique (IR), with a Wright's peak flow meter (WPEF), and by flow‐volume spirometry (FVS). The measurements were done before and 10 min after exercise. In addition, WPEF was measured at 5, 15, and 20 min after exercise. A fall of 15 % or more in WPEF associated with wheezing or cough symptoms was considered a positive test. The exercise challenge was positive in 16 (32%) of the 50 children. Measurements at 10 min by WPEF identified 9 positive cases. At the same time point the IR identified 10 positive cases; a rise in resistance of 15% or more was considered positive, giving it 80% sensitivity and 93% specificity. The repeatability coefficient (CoR) for the interrupter technique was 0.06 kPa × L −1 × s (13%) before and 0.07 kPa × L −1 × s (14%) after exercise. The IR provides a useful alternative for estimation of airway obstruction in children following exercise challenge. The results were comparable with the current reference methods of forced expiratory volume in 1 s and peak flow measurements. Pediatr Pulmonol. 1999; 27:203–207. © 1999 Wiley‐Liss, Inc.