Premium
Bronchial challenge with carbachol in 3–6‐year‐old children: Body plethysmography assessments
Author(s) -
Badier M.,
Guillot C.,
Dubus J.C.
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(199902)27:2<117::aid-ppul8>3.0.co;2-h
Subject(s) - plethysmograph , carbachol , medicine , airway resistance , airway , asthma , repeatability , anesthesia , spirometry , endocrinology , chemistry , chromatography , stimulation
Several studies of airway responsiveness in young children (3–6 years old) have been reported, but few have attempted measurements of airway resistance by body plethysmography. Therefore, we decided to study nonspecific bronchial responsiveness following cumulative doses of inhaled carbachol in 44 children with clinical asthma (CA group), 44 children with chronic cough (CC group), 38 children with wheezy bronchitis in the first 2 years of life (WB group), and 40 controls. Specific airway resistance (sRaw) was measured in a body plethysmograph, and specific airway conductance (sGaw=1/sRaw) was calculated. Two parameters were used to assess individual bronchial responses: 1) PD 100 (the dose of carbachol which induced a 100% increase in sRaw), and 2) bronchial reactivity (BR), i.e., the slope of the log‐dose sGaw response to carbachol. Significant differences were observed in PD 100 and BR between the control group and the three groups of young patients ( P < 0.001). Moreover, PD 100 of the CA group was significantly lower than in the CC group (83.1 ± 7.8 μg vs. 108.0 ± 10.2 μg, respectively, P < 0.05), but was similar to the WB group PD 100 (94.4 ± 8.5 μg). BR in the CA group was significantly higher than in both the CC and WB groups (0.127 ± 0.009 cm H 2 O‐L.sec −1 · log μg −1 vs. 0.073 ± 0.006 cm H 2 O −1 · sec −1 · log μ −1 and 0.082 ± 0.006 cm H 2 O −1 · sec −1 · log μg −1 , respectively, P < 0.001). Repeatability and coefficients of variation were always acceptable. Continuous SaO 2 monitoring in some children of the CA group demonstrated the safety of the method, which is proposed as a technique in future studies. Pediatr Pulmonol. 1999; 27:117–123. © 1999 Wiley‐Liss, Inc.