92024
document
Bronchodilator response to salbutamol after spontaneous recovery from nonspecific bronchial provocation tests in asthma . Assessment of airway responsiveness by bronchoprovocation and bronchodilatation tests is important in the diagnostic work-up protocol of bronchial asthma and it would be convenient to undertake both tests on the same occasion . However , it is not known whether this can be done accurately . Therefore , this study evaluated the effect of a prior bronchial provocation test on the bronchodilator response to salbutamol after spontaneous recovery of the forced expiratory volume in one second ( FEV1 ) in a group of asthmatic subjects . On two separate occasions at the same time of day , concentration-response studies with inhaled histamine or methacholine , or a sham challenge with normal saline were carried out in a blinded , randomized manner . Changes in airway calibre were followed as FEV1 and agonist responsiveness expressed as the provocative concentration causing a 20 % fall in FEV1 ( PC20 ) . After either spontaneous recovery or a fixed-duration wait of 45 min ( when appropriate ) , the subjects received 2x100 microg of salbutamol from a metered dose inhaler with a spacer . The bronchodilator response to salbutamol was expressed as a percentage of initial FEV1 ( deltaFEV1 % init ) . Bronchial challenge with both agonists failed to alter significantly the airway response to salbutamol , with the deltaFEV1 % init mean value ( range ) being 16.9 % ( 9.0-31.9 ) and 17.5 % ( 11.6-31.2 ) on the sham and histamine/methacholine challenge day respectively . It was shown that the degree of bronchodilatation achieved after salbutamol 200 microg is not affected by prior bronchoprovocation testing when enough time is allowed for the airways to recover spontaneously to baseline forced expiratory volume in one second . Thus evaluation of airway responsiveness by both bronchial provocation tests and bronchodilator testing can be assessed reliably within a few hours in asthmatic patients .
92025
Intervention_Pharmacological
salbutamol
92026
Intervention_Pharmacological
salbutamol
92027
Intervention_Pharmacological
histamine
92028
Intervention_Pharmacological
methacholine
92029
Intervention_Pharmacological
sham challenge with normal saline
92030
Intervention_Pharmacological
salbutamol
92031
Outcome_Physical
FEV1
92032
Outcome_Physical
FEV1
92033
Outcome_Physical
FEV1
92034
Outcome_Physical
initial FEV1
92035
Outcome_Physical
airway response
92036
Outcome_Physical
deltaFEV1 % init mean value
92037
Participant_Condition
asthma
92038
Participant_Condition
bronchial asthma