Airway responsiveness in infants following bronchiolitis.
Pediatr Pulmonol
; 13(1): 6-10, 1992 May.
Article
em En
| MEDLINE
| ID: mdl-1589316
ABSTRACT
Airway responsiveness to inhaled methacholine was assessed in 18 infants, 4 and 10 months old, following bronchiolitis. Pulmonary function was measured from partial expiratory flow-volume curves generated by the rapid compression technique. Sleeping infants inhaled increasing concentrations of methacholine until maximal expiratory flows at functional residual capacity (VmaxFRC) decreased by 30% or 2.5 mg/mL was inhaled. Airway responsiveness was quantitated by 1) the threshold concentration (log TC) required to decrease VmaxFRC by 2 standard deviations from baseline; 2) the concentration required to decrease VmaxFRC by 30% (log PC30); and 3) the slope of the dose-response curve between TC and PC30 (log SPC30). At both the first and second evaluation, the bronchiolitic infants had lower baseline VmaxFRC (% pred.) than 24 control infants. In addition, the bronchiolitic infants had heightened airway responsiveness compared to controls, demonstrating lower values for logTC and logPC30 and steeper slopes to their dose-response curves (logSPC30). After accounting for the relationship between airway responsiveness and age, the occurrence of bronchiolitis was found to be a significant independent factor 10 months but not 4 months following bronchiolitis. The bronchiolitic infants did not demonstrate the decline in airway responsiveness with increasing age that occurs in normal infants. We conclude that infants exhibit heightened airway responsiveness following bronchiolitis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transtornos Respiratórios
/
Bronquiolite Viral
/
Ventilação Pulmonar
Tipo de estudo:
Etiology_studies
/
Observational_studies
/
Risk_factors_studies
Limite:
Female
/
Humans
/
Infant
/
Male
Idioma:
En
Revista:
Pediatr Pulmonol
Assunto da revista:
PEDIATRIA
Ano de publicação:
1992
Tipo de documento:
Article