Actively Recruiting
Hypercapnia in Orthostatic Hypotension
Led by University of Calgary · Updated on 2026-05-05
80
Participants Needed
1
Research Sites
430 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
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
CONDITIONS
Official Title
Hypercapnia in Orthostatic Hypotension
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Age 18 years or older
- Male and female participants
- Non-smokers
- Able and willing to provide informed consent
- Able to travel to the Autonomic Testing Lab at the University of Calgary, Calgary, AB
You will not qualify if you...
- Medical therapies or medications that could interfere with autonomic function testing
- Presence of somatization or severe anxiety symptoms
- Pregnant or breastfeeding females
- Inability to tolerate wearing a mask for the study duration
- Use of portable oxygen at rest or during exercise
- Chronic heart failure or severe lung disease causing inability to climb one flight of stairs due to shortness of breath
- Other organ system failures or illnesses affecting autonomic function or study participation, including dementia, alcohol or drug abuse, cerebrovascular disease, kidney or liver disease, or nerve damage from surgery
- Any other factors that the investigator believes would prevent study completion or compliance
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Trial Site Locations
Total: 1 location
1
University of Calgary
Calgary, Alberta, Canada
Actively Recruiting
Research Team
J
Jacquie Baker, PhD
CONTACT
R
Rasha Hamzeh, RN
CONTACT
How is the study designed?
Study Type
INTERVENTIONAL
Masking
NONE
Allocation
RANDOMIZED
Model
CROSSOVER
Primary Purpose
TREATMENT
Number of Arms
5
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