The Effects of CPAP Withdrawal on Cerebral Vascular Reactivity and Brain Oxygenation in OSA (NCT02493673) | Clinical Trial Compass
CompletedNot Applicable
The Effects of CPAP Withdrawal on Cerebral Vascular Reactivity and Brain Oxygenation in OSA
Switzerland49 participantsStarted 2015-06
Plain-language summary
Obstructive sleep apnoea (OSA) is a highly prevalent sleep-related breathing disorder associated with adverse cardiovascular outcome. Underlying mechanisms are subject of debate. A causal relationship between OSA and systemic hypertension as well as peripheral endothelial dysfunction was shown, and there is accumulating evidence from physiologic and observational studies that cerebral autoregulation is insufficient to protect the brain from the nocturnal consequences of OSA. However, there are no data from randomised controlled trials proving a causal relationship between OSA and impaired cerebral vascular reactivity (CVR). The aim of this randomised controlled trial is to study the effects of a short-term CPAP withdrawal, and thus returning OSA, on daytime CVR and brain oxygenation to establish whether there is a causal relationship between OSA and cerebral vascular damage.
Who can participate
Age range
20 Years – 75 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Objectively confirmed OSA (at the time of original diagnosis) with an oxygen desaturation index (ODI) and apnoea-hypopnoea-index (AHI) of ≥20/h.
* Currently an oxygen desaturation index (≥4% dips) of ≥15/h during an ambulatory nocturnal pulse oximetry performed on the last night of a four-night period off CPAP.
* Treated with CPAP for more than 12 months
* Device usage \>4h per night, \>80% of the last 365 days, and AHI\<10 with treatment (according to CPAP machine download data).
* Age between 20 and 75 years.
* Written informed consent as documented by signature.
Exclusion Criteria:
* Previous ischemic or haemorrhagic stroke; known cerebral aneurysm or arterio-venous malformation.
* Carotid artery stenosis \> 70%
* Use of alpha- and beta-adrenergic blocking medication, antianginal medications, triptans, selective COX-inhibitors
* Unstable, untreated coronary or peripheral artery disease, severe arterial hypertension or hypotension (\>180/110 or \<90/60mmHg)
* Implanted pacemaker or internal cardiac defibrillator
* Changes in medication during the trial
* Previous ventilatory failure (awake SpO2 \<93% andPaCO2\>6kPa).
* Obesity hypoventilation syndrome, COPD
* Previously diagnosed with Cheyne-Stokes breathing.
* Current professional driver or any previous sleep related driving accidents.
* Caffeine or nicotine abuse 12 hours before measurements
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Cerebrovascular reactivity (CVR)
Timeframe: Change from baseline in CVR after 2 weeks of CPAP withdrawal