Using a CO2 rebreather to improve blood pressure in patients with neurogenic orthostatic hypotension

CO2 Rebreathing to Increase Blood Pressure in Neurogenic Orthostatic Hypotension: A Proof-of-Concept Pilot Study

Not applicable Interventional University of Calgary · NCT05908760

This study is testing whether a CO2 rebreather can help people with neurogenic orthostatic hypotension improve their blood pressure and feel better when standing up.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment28 (estimated)
Ages18 Years to 100 Years
SexAll
SponsorUniversity of Calgary Academic / other
Locations1 site (Calgary, Alberta)
Trial IDNCT05908760 on ClinicalTrials.gov

What this trial studies

This pilot study evaluates the effectiveness of a CO2 rebreather device in improving blood pressure and orthostatic tolerance in patients diagnosed with neurogenic orthostatic hypotension (nOH). The study is based on the hypothesis that increasing arterial CO2 levels through rebreathing can enhance blood pressure responses in these patients. The intervention involves capturing and re-inhaling expired CO2 to transiently elevate CO2 levels, potentially offering a novel treatment approach for managing nOH symptoms. The study will include 28 participants who meet specific eligibility criteria and will be conducted at the University of Calgary.

Who should consider this trial

Good fit: Ideal candidates for this study are adults aged 18 and older with a physician diagnosis of neurogenic orthostatic hypotension.

Not a fit: Patients with chronic heart failure, severe pulmonary disease, or other systemic illnesses affecting autonomic function may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could significantly improve blood pressure regulation and quality of life for patients suffering from neurogenic orthostatic hypotension.

How similar studies have performed: While this approach is novel, previous studies have indicated that hypercapnia can improve blood pressure in patients with nOH, suggesting potential for success.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age ≥18 years
* Male and Female
* Physician diagnosis of Neurogenic Orthostatic Hypotension
* 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
* Pregnant or breast-feeding females
* 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 Neurogenic Orthostatic HypotensionAutonomic Failure
Last reviewed 2026-06-13 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.