Nebulised water as a bronchoconstricting challenge in infancy.
The pulmonary response to inhalation challenge with nebulised distilled water was measured in 100 sedated infants with a history of wheeze. Lung function was measured by total body plethysmography. Satisfactory results were obtained in 88 infants. Fifty one were considered to have responded by developing a greater than 20% decrease in specific conductance (sGaw) after nebulised water. Thirty two of these infants had previously been challenged with nebulised saline before but only one showed a greater than 20% decrease in sGaw after saline. Twenty infants who developed signs of bronchoconstriction after challenge with nebulised water were rechallenged 20 minutes later. After the initial challenge a fall in sGaw of greater than 20% was found in 19 of the 20. After a second challenge with nebulised water only 15 (75%) showed a 20% or greater decrease in sGaw. Nine of the 20 infants remained sedated and were rechallenged for a third time. Eight showed a greater than 20% decrease in sGaw. This study indicates that approximately 60% of infants with a history of wheeze will bronchoconstrict in response to inhaled nebulised water and that up to 75% show no evidence of a subsequent refractory period to inhaled water challenge.
Department of Child Health, University Hospital, Nottingham.
C
C
O'Callaghan
A D
AD
Milner
M S
MS
Webb
A
A
Swarbrick
D000280:Administration, Inhalation; D000403:Airway Resistance; D001985:Bronchial Provocation Tests / Q000379:methods*; D016084:Bronchoconstriction; D006801:Humans; D007223:Infant; D008168:Lung / Q000503:physiopathology; D010993:Plethysmography, Whole Body; D012135:Respiratory Sounds / Q000503:physiopathology*; D014867:Water / Q000008:administration & dosage / Q000494:pharmacology*
D014867:Water