Search

Objective: To evaluate bronchial hyperresponsiveness in children under 4 years of age with recurrent wheezing bronchitis, and to determine if its presence or absence can predict the subsequent progression to a transient or persistent wheezing bronchitis phenotype., Population and Methods: A bronchial challenge test was performed with methacholine using a modified tidal volume method, without sedation in a group of patients from 8 to 47 months of age with recurrent wheezing bronchitis and a control group of healthy children. A decrease in oxygen saturation of ≥ 5% or an increase in respiration rate of >50% [PCwheeze (PCw)] was considered a positive response. The patients were subsequently clinically followed up to assess their progress., Results: A total of 63 patients and 16 controls were studied (mean age 23.9 vs. 25.2 months). The PCw was lower than the control group (≤ 4 mg/ml) in 43 (68%) children from the bronchitis group (P<0.001). No significant adverse effects were observed on performing the test. After a mean follow up of 28.5 months, completed in 49 of the patients, no differences were seen between the presence of bronchial hyperresponsiveness at the beginning of the study and the subsequent progression to transient, infrequent and frequent wheezing (P=0.63)., Conclusions: A high percentage of children under 4 years of age affected by wheezing bronchitis had a bronchial hyperresponse. The subsequent progression to transient or persistent wheezing bronchitis phenotype is not associated with bronchial hyperresponsiveness., (Copyright © 2010 SEPAR. Published by Elsevier Espana. All rights reserved.)

Background: The objective of the study was to assess bronchial inflammation in preschool children with recurrent bronchitis by measuring exhaled nitric oxide., Patients and Methods: The study included patients under 4 years of age with at least 3 episodes of wheezing in the past year (n=63) and a control group (n=30). Exhaled nitric oxide was measured in samples collected offline during spontaneous tidal breathing with a face mask and stored in Mylar balloons., Results: The fractional exhaled nitric oxide concentration (FE(NO)) was higher in the group with bronchitis (mean [SD], 5.3 [1.3] parts per billion [ppb]) than in the control group (4.6 [1.1]ppb) (P=.02). There was a significant difference between the control group and children in the bronchitis group not treated with inhaled corticosteroids (P<.05), but not between controls and corticosteroid-treated patients. A relationship with eosinophil count was observed in that those with higher counts (>400 microL) had higher FE(NO) levels (P<.01). No relationship was observed between FE(NO) and a positive methacholine challenge test. Follow-up lasted at least 20 months. The initial FE(NO) level did not differ significantly according to whether patients were subsequently transient, infrequent, or frequent wheezers (5.2 [0.98]ppb, 5.6 [1.5]ppb, and 4.8 [1.34]ppb, respectively; P=.36)., Conclusions: In children under 4 years of age with recurrent wheezing bronchitis who were asymptomatic at study entry, a small increase in FE(NO) was observed although there was a good deal of overlap with the control group.

Objective: To assess the safety of the tracheal auscultation method for measuring bronchial hyperresponsiveness in healthy unsedated children aged less than 4 years and to establish a range of normal bronchial hyperresponsiveness values., Population and Methods: The study population consisted of healthy children aged between 6 months and 4 years. A methacholine bronchial provocation test was administered to unsedated children, using the tidal volume breathing technique and applying an abbreviated protocol. The test was considered positive when wheezing was heard in the trachea, arterial oxygen saturation (SaO2) fell by 5% or more, or respiratory rate increased by 50% or more., Results: A total of 16 children were studied. Ages ranged from 8 to 47 months, with a mean (SD) of 23.5 (12.2) months. There was no response to the methacholine in 11 children. In the other 5 children, there was a positive response at a concentration of 8 mg/mL. Response to the test was considered positive on the basis of tracheal wheezing in 3 cases, tracheal wheezing and a fall in SaO2 in 1 case, and a fall of SaO2 of 5% or more in 1 case. SaO2 never fell below 93%., Conclusions: As a means for assessing bronchial hyperresponsiveness, the tracheal auscultation method is appropriate, is simple to apply, and can be safely administered to unsedated children aged less than 4 years. The lowest concentration at which a response to methacholine occurs in healthy children of this age group is 8 mg/mL.