Hypercapnia in Orthostatic Hypotension (NCT05295810) | Clinical Trial Compass
RecruitingNot Applicable
Hypercapnia in Orthostatic Hypotension
Canada80 participantsStarted 2022-03-01
Plain-language summary
The Autonomic (or "automatic") Nervous System (ANS) regulates internal processes, including control of heart rate and blood pressure (BP). When someone stands, and gravity tries to pull blood away from the brain, the ANS works to maintain BP and brain blood flow. Neurogenic Orthostatic Hypotension (NOH) occurs when our "fight-or-flight" part ("sympathetic") of the ANS fails. BP can drop a lot when upright, reducing blood flow and oxygen delivery to the brain, and this can cause symptoms of light-headedness, nausea, and fainting.
One solution to help counter the effects of NOH may be to increase sympathetic activity by breathing higher levels of carbon dioxide. In healthy volunteers, small increases in the amount of inhaled carbon dioxide has been shown to increase BP in the upright position, and this improves symptoms!
The objectives of the current study are to apply carbon dioxide in patients with NOH and healthy controls to: (a) evaluate the effects of breathing carbon dioxide on BP and brain blood flow, and (b) determine if a device that increases carbon dioxide while standing will work as a new therapy
Who can participate
Age range
18 Years – 100 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:
* Age ≥18 years
* Male and Female
* Non - smokers.
* Able and willing to provide informed consent.
* Ability to travel to Libin Cardiovascular Institute Autonomic Testing Lab at the University of Calgary, Calgary, AB.
Exclusion Criteria:
* Medical therapies or medications which could interfere with testing of autonomic function
* Participants with somatization or severe anxiety symptoms will be excluded
* Pregnant or breast-feeding females
* Inability to tolerate mask for the duration of the study
* Subjects who require portable oxygen at rest or with exercise
* Subjects with chronic heart failure or severe pulmonary disease who are unable to climb one flight of stairs due to shortness of breath.
* Presence of failure of other organ systems or systemic illness that can affect autonomic function or the participant's ability to cooperate. These include: dementia, alcohol and/or drug abuse, cerebrovascular disease, kidney or liver disease, surgical procedures where the nerves of the sympathetic nervous system have been cut.
* Other factors which in the investigator's opinion would prevent the participant from completing the protocol, including poor compliance during previous studies.
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
Δ Blood Pressure (BP)
Timeframe: The ΔBP (stand-sit) calculated as the average BP in the final minute of sitting and the average BP between minute 3 and 5 of stand will be compared between room air and +10mmHg of CO2