Large and small airway responses to procaterol hydrochloride administered through different extension devices in asthmatic patients.
J Aerosol Med
; 12(3): 177-85, 1999.
Article
en En
| MEDLINE
| ID: mdl-10623334
ABSTRACT
The effects of spacer devices on the magnitude and velocity of large and small airway bronchodilator responses in asthmatic patients who can correctly operate a metered dose inhaler (MDI) remain unclear. According to a double-blinded, randomized, crossover protocol, 14 asthmatic patients were studied on seven separate occasions. On each occasion, patients inhaled doubling methacholine concentrations until forced expiratory volume in 1 second (FEV1) had fallen by 20% of baseline. Changes in forced expiratory flow between 25% and 75% of vital capacity (FEF25-75) were also evaluated. Subsequently, patients were administered 20 or 50 micrograms of procaterol from an MDI either alone or in conjunction with a small- or large-volume spacer device. Changes in FEV1 and FEF25-75 corrected for baseline forced vital capacity (isoFEF25-75) were assessed at 3-minute intervals for 15 minutes and at 30 minutes. Spontaneous recovery was similarly evaluated. The time required to attain significant increases in both FEV1 and isoFEF25-75 was calculated in bronchodilator trials. With 20 micrograms of procaterol, both spacers allowed larger and faster FEV1 increases than the MDI alone (P < 0.01); with 50 micrograms, the velocity and magnitude of FEV1 increases were further enhanced in trials with the MDI alone. The lower procaterol dose via the large-volume spacer determined larger and faster isoFEF25-75 increases than the higher dose via both the small-volume spacer and the MDI alone (P < 0.01). Spacers enhance bronchodilation even in patients using MDIs optimally. Compared with both the small-volume device and the MDI alone, the large-volume spacer allows faster and larger small airway dilation with less than half of the procaterol dose.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Asma
/
Nebulizadores y Vaporizadores
/
Bronquios
/
Broncodilatadores
/
Procaterol
Tipo de estudio:
Clinical_trials
/
Diagnostic_studies
Límite:
Adolescent
/
Adult
/
Child
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
J Aerosol Med
Asunto de la revista:
TERAPIA POR MEDICAMENTOS
Año:
1999
Tipo del documento:
Article
País de afiliación:
Italia