An isoflow-volume technique for assessing airway dynamics in children and adults.
Respiration
; 68(2): 192-9, 2001.
Article
em En
| MEDLINE
| ID: mdl-11287835
ABSTRACT
BACKGROUND:
We propose a new approach to the measurement of small airway function as an alternative to recordings of maximal expiratory flow-volume (MEFV) curves.OBJECTIVES:
A newly developed technique to record isoflow-volume (IFV) curves to be tested against maximal respiratory flow curves.METHODS:
An isoflow whistle (IFW; Iflopen) measures the length of a constant expiration after full inspiration. The note of the whistle enables a subject to generate an even expiration, and the isoflow maintenance times at 1 l x s(-1) (IFMT1) and 2 l x s(-1) (IFMT2) are recorded. The accuracy and reproducibility of the IFV technique were evaluated in 17 healthy adults (age 17-55 years) and in 14 asthmatic children (age 6-14 years). Comparisons with standard lung function parameters, such as forced expiratory volume in 1 s (FEV1), maximal expiratory flow at 50% (MEF50) and 25% (MEF25) vital capacity and peak expiratory flow (PEF), obtained with a Wright Peakflow Meter were undertaken in 102 healthy (aged 8-14 years) and 101 asthmatic children (aged 6-17 years). A bronchial challenge test was performed in 13 asthmatic children.RESULTS:
The expired volume measured by the IFW showed an acceptable agreement with that of a pneumotachograph (mean error of 4.32% for IFMT1 and 5.93% for IFMT2). In healthy and in asthmatic children, the correlations between FEV1 and IFMT1 or IFMT2 (r = 0.92 and 0.94, respectively) were found to be greater than that between FEV1 and PEF (r = 0.68). During bronchial challenge tests in 13 asthmatic children, the FEV1 decreased to 69% of baseline and IFMT1 to 58% of baseline.CONCLUSIONS:
The IFV technique accurately measured airway obstruction and closely followed changes in standard parameters of the MEFV curve.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ventilação Pulmonar
/
Obstrução das Vias Respiratórias
Tipo de estudo:
Evaluation_studies
Limite:
Adolescent
/
Adult
/
Child
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Respiration
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Suíça