Maximal Voluntary Ventilation (MVV) correlates well with maximal exercise capacity and is used to assess the ventilatory function during exercise in COPD (Chronic Obstructive Pulmonary Disease) patients. Dynamic hyperinflation (DH) often occurs during MVV in COPD and is believed to be due to expiratory flow limitation. The present study is intended to assess whether DH can also occur during MVV in normal subjects without expiratory flow limitation.
Maximal voluntary ventilation (MVV) correlates well with maximal exercise capacity and is used to assess the ventilatory function during exercise in COPD (Chronic Obstructive Pulmonary Disease) patients. Dynamic hyperinflation (DH) often occurs during MVV in COPD and is believed to be due to expiratory flow limitation. The present study is intended to assess whether DH can also occur during MVV in normal subjects without expiratory flow limitation. Study design: healthy subjects with normal lung function will perform MVV at increasing breathing frequencies and maximal tidal volume, from 10 to 100 cycles per minute. Inspiratory capacity (IC) will be measured at rest and after each 12 seconds of MVV in order to detect DH. From the moment DH appeares at a given frequency, only one additional MVV at a higher breathing frequency will be conducted to confirm DH.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
45
Subjects with normal lung function performed MVV at increasing breathing frequencies and maximal tidal volume, from 10 to 100 cycles per minute. Inspiratory capacity (IC) was measured at rest and after each 12 seconds of MVV in order to detect DH. From the moment DH appeared at a given frequency, only one additional MVV at a higher breathing frequency was conducted to confirm DH.
CHU St. Pierre
Brussels, Brussels Capital, Belgium
RECRUITINGFrequency which induces Dynamic Hyperinflation
We analyze Frequency of Maximal Voluntary Ventilation (MVV) which induces a significant decrease of the Inspiratory Capacity (IC) post MVV compared to the IC at rest.
Time frame: day one
Correlation between the frequency which induces Dynamic Hyperinflation (DH) and Forced Expiratory Volume in one second
We analyze if there is a good correlation between the frequency which induces a significant Dynamic Hyperinflation (DH) and Forced Expiratory Volume in one second
Time frame: day one
Correlation between the frequency which induces Dynamic Hyperinflation (DH) and Forced Vital Capacity
We analyze if there is a good correlation between the frequency which induces a significant Dynamic Hyperinflation (DH) and Forced Vital Capacity
Time frame: day one
Correlation between the frequency which induces Dynamic Hyperinflation (DH) and Forced Expiratory Flows at 25%, 50% and 75% of Forced Vital Capacity
We analyze if there is a good correlation between the frequency which induces a significant Dynamic Hyperinflation (DH) and Forced Expiratory Flows at 25%, 50% and 75% of Forced Vital Capacity
Time frame: day one
Correlation between the frequency which induces Dynamic Hyperinflation (DH) and age
We analyze if there is a good correlation between the frequency which induces a significant Dynamic Hyperinflation (DH) and age
Time frame: day one
Correlation between the frequency which induces Dynamic Hyperinflation (DH) and body mass index
We analyze if there is a good correlation between the frequency which induces a significant Dynamic Hyperinflation (DH) and body mass index
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Time frame: day one
Correlation between the frequency which induces Dynamic Hyperinflation (DH) and Inspiratory Capacity at rest
We analyzed if there is a good correlation between the frequency which induces a significant Dynamic Hyperinflation (DH) and Inspiratory capacity at rest
Time frame: day one
Correlation between the frequency which induces Dynamic Hyperinflation (DH) and IC/FVC ratio (IC : Inspiratory Capacity at rest ; FVC : Forced Vital Capacity)
We analyze if there is a good correlation between the frequency which induces a significant Dynamic Hyperinflation (DH) and IC/FVC ratio (IC : Inspiratory Capacity at rest ; FVC : Forced Vital Capacity)
Time frame: day one
Comparison Maximal Voluntary Ventilation with Forced Expiratory Volume in one second multiplied by 35
We compare Maximal Voluntary Ventilation at the different frequencies with the common predictive value of maximal ventilation obtained by multiplying Forced Expiratory Volume in one second by 35
Time frame: day one