Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT01067534 |
| Other study ID # |
FOT_PATR_2010 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
February 10, 2010 |
| Last updated |
January 18, 2011 |
| Start date |
February 2010 |
| Est. completion date |
January 2011 |
Study information
| Verified date |
April 2010 |
| Source |
University of Patras |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
Greece: National Organization of Medicines |
| Study type |
Interventional
|
Clinical Trial Summary
Studies evaluating response to bronchodilation in flow-volume spirometry and/or by forced
oscillations technique (FOT), have been conduced in subjects with obstructive airways
diseases. Less is known about bronchodilation responses, assessed by both spirometry and FOT
in healthy young subjects.
The purpose of the present study is
1. to determine the range of the bronchodilation response in terms of changes in selected
spirometric parameters in healthy non-smoking young adults, for identifying normal
response after an inhaled bronchodilatory agent versus placebo, and its anthropometric
and spirometric determinants
2. to determine the range and characteristics of bronchodilation response using
pseudorandom FOT in healthy non-smoking young adults, for identifying normal response
after an inhaled bronchodilatory agent versus placebo, and its anthropometric and
oscillometric determinants.
3. to compare and correlate eventual changes in spirometric and oscillometric parameters.
The investigators hypothesize that exists a normal variation in spirometric and
oscillometric parameters after bronchodilation, and that these parameters are correlated.
Description:
INTRODUCTION
Studies evaluating response to bronchodilation in flow-volume spirometry and/or by forced
oscillations technique (FOT), have been conduced in subjects (children or adults) with
obstructive airways diseases. Less is known about bronchodilation responses, assessed by
both spirometry and FOT in healthy young subjects.
PURPOSE
The purpose of the present study is
1. to determine the range of the bronchodilation response in terms of changes in PEF,
FEV1, FEF25, FEF50, FEF75, and FEF25-75, in healthy non-smoking young adults, for
identifying normal response after an inhaled bronchodilatory agent versus placebo, and
its anthropometric and spirometric determinants
2. to determine the range and characteristics of bronchodilation response using
pseudorandom FOT in healthy non-smoking young adults, for identifying normal response
after an inhaled bronchodilatory agent versus placebo, and its anthropometric and
oscillometric determinants.
3. to compare and correlate eventual changes in spirometric and oscillometric parameters.
MATERIAL AND METHODS
The study will be conduced in the Laboratory of Respiratory Functions of the University
Hospital of Patras, Patras, Greece.
Healthy, non-smoking young adults (medical students and residents) will be voluntary
included. Participants will be assessed for eligibility with a structured interview which
include questions regarding respiratory symptoms (wheezing, attacks off shortness of breath,
sputum production, and dyspnea at rest or on exertion), diagnosed respiratory diseases, and
use of pulmonary medication. A subject will be considered as non-smoker if he/she has never
smoked or has discontinued smoking at least 5 years prior to entering the study.
Anthropometric data will be obtained at the enrollment. All oscillometric and spirometric
measurements will be performed during morning hours (09:00 to 12:00). Subjects will be
advised to refrain from consuming coffee or tea, and engaging in heavy eating for 2 hours.
Respiratory impedance spectra (Zrs), yielding resistance (Rrs) and reactance (Xrs) as a
function of frequency, will be obtained using a commercially available device (i2m, Chess
Medical, Belgium), in accordance with the ERS 2003 guidelines. The forced oscillatory signal
is a pseudorandom signal consisting of frequency components between 4 and 48 Hz with a
measurement period of 8 sec. During measurement the subject will be seated comfortably
upright with the neck in the neutral position and the arms resting comfortably by the side.
The cheeks and lower jaw of the subject will be firmly supported by a staff member during
all measurements. Participants will be connected to the device via a mouthpiece
incorporating a bacterial filter and instructed to breathe normally with a nose clip in
place. Five technically acceptable measurements will be obtained. A measurement will be
considered unacceptable if coherence will be <0.95 at 2 or more frequencies or if Zrs show
obvious artifacts. The calibration of the device will be checked daily with a known
resistance. All measurements will be performed by the same trained respiratory physician.
Spirometric measurements will always follow FOT measurements. Spirometry will be completed
with a flow-volume device (MasterScreen IOS, Viasys/Jaeger; Höchberg, Germany), with the
subject seated, using ATS 1994 criteria for performing the maneuver. Nose clips and
disposable bacterial filters will be used. At least three technically acceptable
measurements will be recorded with a maximum of eight efforts. All measurements will be
performed by the same trained respiratory physician. The calibration of the device will be
checked daily with a 3-L calibration syringe (Viasys/Jaeger; Höchberg, Germany).
The subjects will inhale 0.4mg of salbutamol (Aerolin, GlaxoSmithCline, London, UK) through
a spacer device (Volumatic, GlaxoSmithCline), or a placebo inhaler (Allen & Hanburys LTD,
Greenford, UK) again through a similar spacer. Special measures will be taken to ensure the
blindness of the participants regarding the received inhaler.
Respiratory function measurements (FOT followed by spirometry) will be repeated (as
described above) 15 min after the inhalation. Subjects will remain seated without consuming
beverages other than water.
Each subject will have two sessions of baseline and post-inhalation measurements; one after
receiving salbutamol and one after placebo. These sessions will be performed one day apart.
The respiratory physician who will perform the measurements will be unaware regarding the
received inhaler.
All technically acceptable Zrs measurements will be averaged and mean Rrs and Xrs at 4, 6,
8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, and 48 Hz
will be calculated. The resonance frequency, the average Rrs between 4-24 Hz (Rrs 4-24) and
4-48 Hz (Rrs 4-48), and the frequency dependence of Rrs 4-24 and Rrs 4-48 will be also
assessed. Absolute and relative changes after bronchodilation or placebo will be examined.
Spirometric variables which will used in analysis will include PEF, FEV1, FEF25, FEF50,
FEF75, and FEF25-75. Absolute and relative changes after bronchodilation or placebo will be
examined.
Multiple linear regression analysis will be performed to determine the individual effects of
the following factors on absolute and relative bronchodilatory responses: age, sex, height,
weight, BMI, and baseline lung function. The Pearson correlation will be used to assess the
association of oscillometric and spirometric variables. All analyses will be performed using
SPSS 17 for windows (SPSS, Chicago, IL).
