Brain waves during ventilatory response tests

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

Status

Recruiting

Phases

Unknown

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12612000454875

Acronym

Nil

Enrollment

Registered

2012-04-23

Start date

2012-04-23

Completion date

Unknown

Last updated

2020-01-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

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.

Interventions

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.

Study design

Allocation

Non-randomised trial

Intervention model

Single group

Primary purpose

Diagnosis

Masking

Open (masking not used)

Eligibility

Sex/Gender

All

Age

18 Years to 65 Years

Healthy volunteers

Yes

Inclusion criteria

Healthy normal subjects and obstructive sleep apnea patients with apnea/hypopnea index (AHI)>15.

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

Outcome results