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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
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
Trial website
Trial related presentations / publications
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
david.wang@sydney.edu.au
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
david.wang@sydney.edu.au

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.