Deep inspiration volume and the impaired reversal of bronchoconstriction in asthma.
Respir Physiol Neurobiol
; 189(3): 506-12, 2013 Dec 01.
Article
em En
| MEDLINE
| ID: mdl-23994826
ABSTRACT
It is unclear whether the failure to reverse bronchoconstriction with deep inspiration (DI) in asthma is due to reduced maximal dilatation of the DI. We compared the effect of different DI volumes on maximal dilatation and reversal of bronchoconstriction in nine asthmatics and ten non-asthmatics. During bronchoconstriction, subjects took DI to 40%, 70% and 100% inspiratory capacity, on separate days. Maximal dilatation was measured as respiratory system resistance (Rrs) at end-inspiration and residual dilatation as Rrs at end-expiration, both expressed as percent of Rrs at end-tidal expiration prior to DI. DI volume was positively associated with maximal dilatation in non-asthmatics (ANOVA p=0.055) and asthmatics (p=0.023). DI volume was positively associated with residual dilatation in non-asthmatics (p=0.004) but not in asthmatics (p=0.53). The degree of maximal dilatation independently predicted residual dilatation in non-asthmatics but not asthmatics. These findings suggest that the failure to reverse bronchoconstriction with DI in asthma is not due to reduced maximal dilatation, but rather due to increased airway narrowing during expiration.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Asma
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Broncoconstrição
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Cloreto de Metacolina
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Agonistas Muscarínicos
Tipo de estudo:
Prognostic_studies
Limite:
Adult
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Female
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Humans
/
Male
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article