Effect of respiratory rate on respiratory patterns in patients with chronic obstructive pulmonary disease.
Intern Med
; 36(11): 771-5, 1997 Nov.
Article
en En
| MEDLINE
| ID: mdl-9392347
ABSTRACT
We enrolled 22 patients with chronic obstructive pulmonary disease (COPD) and 20 normal subjects as controls. Using a hot-wire flow meter, we obtained tidal volume (VT), duty ratio (Ti/Ttot), and mean inspiratory flow (VT/Ti) as measures of respiratory pattern at two different respiratory rates; 0.5 Hz and 1.5 Hz. At 0.5 Hz, there were significant differences in Ti/Ttot and VT/Ti. At 1.5 Hz, patients with COPD had significantly lower values of VT and VT/Ti. Furthermore, we calculated the change ratios from 0.5 Hz to 1.5 Hz in these parameters as new parameters of respiratory pattern change by respiratory rate. VT0.5/1.5 and VT/Ti0.5/1.5 significantly correlated with FEV1.0/FVC. The findings suggest that the parameters of the respiratory pattern may change depending on respiratory rates, and that the ratios of those parameters obtained at two different rates could be helpful in diagnosing airflow obstruction.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Respiración
/
Enfermedades Pulmonares Obstructivas
Tipo de estudio:
Diagnostic_studies
Límite:
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Intern Med
Asunto de la revista:
MEDICINA INTERNA
Año:
1997
Tipo del documento:
Article