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Trial registered on ANZCTR


Registration number
ACTRN12612000454875
Ethics application status
Approved
Date submitted
18/04/2012
Date registered
23/04/2012
Date last updated
24/04/2012
Type of registration
Prospectively registered

Titles & IDs
Public title
Brain waves during ventilatory response tests
Scientific title
A study in normal subjects and obstructive sleep apnea patients undergoing ventilatory response testing, to assess the effects of acute hypoxia and hypercapnia on the electroencephalogram
Secondary ID [1] 280354 0
Nil
Universal Trial Number (UTN)
Nil
Trial acronym
Nil
Linked study record

Health condition
Health condition(s) or problem(s) studied:
obstructive sleep apnea 286318 0
Condition category
Condition code
Respiratory 286558 286558 0 0
Sleep apnoea

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Subjects will be tested ventilatory response to hypercapnia and hypoxia under two standard protocols: Duffin’s modified rebreathing protocol and Rebuck and Campbell protocol. Two channel EEG (C3-A2, C4-A1) will be recorded during the ventilatory response tests. In detail:
Duffin’s rebreathing protocol involves with a ~5-minute session of ventilatory response to hypercapnia under iso-oxia and hyperoxia (PO2=150mmHg), and a 5-minute session of ventilatory response to hypercapnia under iso-oxia and hypoxia (PO2=50mmHg). There will be a 5-minute of breathing room air and a 5-minute of hyperventilation (PCO2 controlled between 19-25 mmHg) prior to each of the two rebreathing sessions.
Rebuck and Campbell protocol tests ventilatory response to hypoxia, which involves with a ~ 5-minute session of rebreathing with a CO2 scrubber in the circuit. There is also a 5-minute of breathing room air prior to the session.
There is a half an hour resting break between the two Duffin's protocol sessions and before the Rebuck and Campbell protocol session.
Intervention code [1] 284719 0
Other interventions
Comparator / control treatment
There is no control group.
Control group
Uncontrolled

Outcomes
Primary outcome [1] 286992 0
Primary outcome of interest is the potential relationship between the change of end tidal PCO2 and the change of EEG spectral power. (End tidal PCO2 is a key parameter measured during the ventilatory response tests using a fast response CO2 analyser.)
Timepoint [1] 286992 0
During the ventilatory response tests, baseline breathing room air phase compared with the hypercapnic phase of the single test session
Secondary outcome [1] 297157 0
Potential relationship between the change of PO2/SpO2 and the change of EEG spectral power. (PO2 is measured by a fast response O2 analyser during the venbtilatory response tests, and SpO2 is measured by an oxymeter using ear-clip sensor.)
Timepoint [1] 297157 0
During the ventilatory response tests, baseline breathing room air phase compared with the hypercapnic phase of the single test session
Secondary outcome [2] 297158 0
Potential difference in the pattern of change of EEG spectral power between normal subjects and sleep apnea patients in responding to hypercapnia and hypoxia.
Timepoint [2] 297158 0
The matching ventilatory response tests sessions

Eligibility
Key inclusion criteria
Healthy normal subjects and obstructive sleep apnea patients with apnea/hypopnea index (AHI)>15.
Minimum age
18 Years
Maximum age
65 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Sleep apnea patients: waking hypoxemia (oxygen saturation < 95%), BMI > 38 kg/m^2, severe COPD or other lung disease, uncontrolled cardiac disease
Normal subjects: No concurrent medical complaint including sleep apnea

Study design
Purpose of the study
Diagnosis
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Nil
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
23/04/2012
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
24
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 285130 0
University
Name [1] 285130 0
New Staff Awards, Sydney University Medical School
Country [1] 285130 0
Australia
Funding source category [2] 285131 0
Government body
Name [2] 285131 0
NHMRC Health Professional Research Fellowship
Country [2] 285131 0
Australia
Primary sponsor type
Hospital
Name
Dept of Respiratory and Sleep Medicine, RPA Hospital
Address
Missenden Rd, Camperdown, NSW 2050
Country
Australia
Secondary sponsor category [1] 283995 0
None
Name [1] 283995 0
Address [1] 283995 0
Country [1] 283995 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 287147 0
Sydney Local Health District, Ethic Review Committee, RPAH Zone
Ethics committee address [1] 287147 0
Research development office, RPAH, Missenden Rd, Camperdown, NSW 2050 Australia
Ethics committee country [1] 287147 0
Australia
Date submitted for ethics approval [1] 287147 0
Approval date [1] 287147 0
08/12/2011
Ethics approval number [1] 287147 0
X11-0325 HREC/11/RPAH/505

Summary
Brief summary
This is a physiological study to assess potential brain waves change during the ventilatory response to hypercapnia and hypoxia tests. We hypothesize that there is an intrinsic link between the change of blood CO2 level and the spectral power of brain waves.
Trial website
Nil
Trial related presentations / publications
Nil
Public notes

Contacts
Principal investigator
Name 34086 0
Address 34086 0
Country 34086 0
Phone 34086 0
Fax 34086 0
Email 34086 0
Contact person for public queries
Name 17333 0
Dr David Wang
Address 17333 0
Dept of Respiratory and Sleep Medicine, RPA Hospital, Missenden Rd, Camperdown, NSW 2050.
Country 17333 0
Australia
Phone 17333 0
61 2 9114 0446
Fax 17333 0
61 2 9515 7196
Email 17333 0
[email protected]
Contact person for scientific queries
Name 8261 0
Dr David Wang
Address 8261 0
Dept of Respiratory and Sleep Medicine, RPA Hospital, Missenden Rd, Camperdown, NSW 2050.
Country 8261 0
Australia
Phone 8261 0
61 2 9114 0446
Fax 8261 0
61 2 9515 7196
Email 8261 0
[email protected]

No information has been provided regarding IPD availability


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.