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Relationship between response to inhaled salbutamol and methacholine bronchial provocation in children with suspected asthma
Author(s) -
Bibi Haim,
Montgomery Mark,
Pasterkamp Hans,
Chernick Victor
Publication year - 1991
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/ppul.1950100404
Subject(s) - salbutamol , medicine , asthma , methacholine , provocation test , asymptomatic , anesthesia , gastroenterology , respiratory disease , pathology , lung , alternative medicine
Fifty children (27 females, 23 males) ages 6–15 years who were referred for evaluation of suspected asthma had baseline FEV 1 and FEF 25‐75 of ⩾ 80% and FEF 50 ⩾ 70% of predicted values. All had these tests repeated on the same day, after inhaling salbutamol. On a subsequent day PC‐20 (methacholine) was determined as an index of bronchial hyperreactivity (BH). Fourteen age‐matched healthy children (6 females, 8 males) were studied in a similar manner. There was no significant relationship between the PC 20 and the change in FEF 25‐75 or FEF 50 following salbutamol. There was a negative correlation between the initial FEV 1 (% predicted) and the percent change in FEV 1 following salbutamol ( P < 0.01). An increase in FEV 1 of >6% occurred in 7/12 (58.3%) patients with PC 20 ⩽ 0.25 mg/mL (Group I); in 7/24 (29.2%) patients with PC 20 = 0.26–2.0 mg/mL (Group II); in only 1/14 (7.1%) patients with PC 20 > 2.1 mg/mL (Group III) and in none of those asymptomatic (control) children with PC 20 > 8.0 mg/mL (Group IV). All subjects who had a change in FEV 1 > 6% after salbutamol had a PC 20 < 8 mg/mL and this test detected the majority of patients with severe BH. However, although the sensitivity of the test was 100%, the predictive value was only 36%. We conclude that in the presence of a normal baseline FEV 1 a change of > 6% following salbutamol inhalation is indicative of bronchial hyperreactivity. Pediatr Pulmonol 1991; 10:244–248.