Effect of voluntary respiratory efforts on breath-holding time.
Respir Physiol Neurobiol
; 157(2-3): 290-4, 2007 Aug 01.
Article
en En
| MEDLINE
| ID: mdl-17324641
ABSTRACT
INTRODUCTION:
Near the end of a maximal voluntary breath-hold, re-inhalation of the expired gas allows an additional period of breath-holding, indicating that the breaking point does not depend solely on chemical drive. We hypothesized that afferents from respiratory muscle and/or chest wall are significant in breath-holding.METHODS:
Nineteen normal adults breathed room air through a mouthpiece connected to a pneumotachograph and were instructed to breath-hold with and without voluntary regular respiratory efforts against an occluded airway.RESULTS:
Fifty one trials with and 53 without respiratory efforts were analyzed. The mean number of efforts per minute was 19+/-2.3 and the mean lowest airway pressure (P(aw)) -16.6+/-5.4 cmH(2)O. Breath-holding time (BHT) did not differ without (33.0+/-18.2 s) and with (29.3+/-12.3 s) efforts. In five patients arterial blood gasses were measured before and at the end of breath-holding and they did not differ between trials without and with efforts, indicating similar chemical drive. Our results suggest that afferents from respiratory muscle and/or chest wall are not the major determinants of BHT.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Respiración
/
Pruebas de Función Respiratoria
/
Adaptación Fisiológica
Límite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Respir Physiol Neurobiol
Año:
2007
Tipo del documento:
Article
País de afiliación:
Grecia