Breathing carbon dioxide to help with low blood pressure when standing

Investigating Hypercapnia to Treat Neurogenic Orthostatic Hypotension

Not applicable Interventional University of Calgary · NCT05295810

This study tests if breathing in carbon dioxide can help people with Neurogenic Orthostatic Hypotension feel better and manage their blood pressure when standing.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment80 (estimated)
Ages18 Years to 100 Years
SexAll
SponsorUniversity of Calgary Academic / other
Locations1 site (Calgary, Alberta)
Trial IDNCT05295810 on ClinicalTrials.gov

What this trial studies

This study investigates the effects of inhaling carbon dioxide on patients with Neurogenic Orthostatic Hypotension (NOH) and healthy controls. The research focuses on how increased levels of carbon dioxide can stimulate the autonomic nervous system to improve blood pressure and alleviate symptoms associated with standing. Participants will undergo sequential gas delivery to assess changes in blood pressure and symptoms during postural transitions. The study also aims to explore potential sex differences in response to this intervention.

Who should consider this trial

Good fit: Ideal candidates for this study are adults aged 18 and older who experience symptoms of low blood pressure upon standing and can provide informed consent.

Not a fit: Patients with chronic heart failure, severe pulmonary disease, or other significant organ system failures may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could provide a novel treatment for patients suffering from Neurogenic Orthostatic Hypotension, improving their quality of life.

How similar studies have performed: While the approach of using carbon dioxide to stimulate sympathetic activity is novel, preliminary evidence in healthy volunteers suggests potential success in improving orthostatic tolerance.

Eligibility criteria

Show full inclusion / exclusion criteria
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.

Where this trial is running

Calgary, Alberta

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Orthostatic HypotensionNeurogenic Orthostatic Hypotension
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.