Controlled CO2 Inhalation for Neurogenic Orthostatic Hypotension

(CO2-nOH Trial)

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Calgary

Disqualifiers: Pregnancy, Heart failure, Pulmonary disease, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial seeks a new method to assist individuals with neurogenic orthostatic hypotension (nOH), a condition where blood pressure drops suddenly upon standing, causing dizziness and fainting. Researchers are testing a device called the CarboHaler to determine if inhaling controlled amounts of carbon dioxide can safely raise blood pressure and relieve these symptoms. Participants will use the device in two ways: once without added CO2 and once with controlled CO2 inhalation to assess the effects. The trial is suitable for non-smoking adults diagnosed with nOH who can travel to the University of Calgary. As an unphased trial, this study provides a unique opportunity to contribute to innovative research that could lead to new treatment options for nOH.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the study team or your doctor.

What prior data suggests that the CarboHaler CO2 delivery device is safe for patients with neurogenic orthostatic hypotension?

Research has shown that increasing CO2 levels in the blood can improve blood pressure in people with neurogenic orthostatic hypotension (nOH) by carefully inhaling CO2. Studies have found that this method can raise blood pressure when standing, potentially reducing symptoms like dizziness and fainting.

However, limited information exists on the safety of controlled CO2 inhalation. Researchers are still investigating the overall safety of CO2 therapy. The study under consideration aims to assess the safety and effectiveness of this treatment. While early results appear promising, further research is necessary to fully understand any possible side effects. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Unlike current treatments for neurogenic orthostatic hypotension, which often involve medications to increase blood pressure, controlled CO2 inhalation is unique because it uses a simple gas delivery method to potentially stabilize blood pressure quickly. Researchers are excited about this treatment because it directly targets the underlying issue of blood flow regulation by using CO2 to stimulate natural physiological responses, potentially offering a faster-acting and non-pharmacological option. This novel approach could provide relief without the side effects commonly associated with traditional drugs.

What evidence suggests that controlled CO2 inhalation is effective for neurogenic orthostatic hypotension?

Research has shown that controlled CO2 inhalation might help manage neurogenic orthostatic hypotension (nOH) by raising blood pressure upon standing. In this trial, participants in the Controlled CO2 Inhalation Arm will use a CO2 delivery device to test this potential benefit. Studies suggest that increased CO2 inhalation can raise blood pressure in these patients. Higher CO2 levels appear to reduce symptoms like light-headedness or fainting. Early results from several trials support the idea that this could be a promising new treatment for nOH. This method might lead to a simple and effective way to improve their quality of life. ^{1 2 3 4 5}

Are You a Good Fit for This Trial?

This trial is for individuals with neurogenic orthostatic hypotension (nOH), a condition causing blood pressure to drop when standing, leading to dizziness and fainting. Participants should have nOH symptoms and be able to undergo Head-up Tilt tests. Specific inclusion and exclusion criteria details are not provided.

Inclusion Criteria

Ability to travel to Libin Cardiovascular Institute Autonomic Testing Lab at the University of Calgary, Calgary, AB.

I am either male or female.

I have been diagnosed with a condition that causes low blood pressure when standing.

Exclusion Criteria

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

Other factors which in the investigator's opinion would prevent the participant from completing the protocol, including poor compliance during previous studies.

I cannot climb stairs without feeling short of breath due to heart or lung problems.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

In-lab Study Day

Participants undergo two Head-up Tilt (HUT) tests with different breathing protocols, one with and one without exogenous CO2 delivery. Heart rate, blood pressure, and breathing parameters are recorded.

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after the in-lab study day

2-4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Controlled CO2 Inhalation

Trial Overview The study is testing the CarboHaler, a device that delivers controlled CO2, to see if it can improve blood pressure and reduce symptoms in nOH patients when they stand up. The effect of CO2 inhalation on systolic BP from lying down to standing will be measured.

How Is the Trial Designed?

Group I: Controlled CO2 Inhalation Arm Experimental Treatment 1 Intervention

In this arm, participants will breathe with the CO2 delivery device in the supine position until BP levels increase. Once a BP increase is observed, participants will be tilted upright and will continue to breathe with the inhalation device during a 10-min HUT test.

Group II: 0% CO2 Arm Placebo Group 1 Intervention

In this arm, participants will breathe with the CO2 delivery device providing no exogenous CO2 while supine and during a 10-min HUT test.

Who Is Running the Clinical Trial?

University of Calgary

Lead Sponsor

Trials

827

Recruited

902,000+

Published Research Related to This Trial

A trial involving a healthy young volunteer demonstrated that induced syncope led to severe hyperventilation and periodic breathing, with hyperventilation rates reaching 57 L/min.

This hyperventilation caused a significant reduction in cerebral blood flow velocity by approximately 65%, highlighting the impact of respiratory changes on brain blood supply even without systemic hypotension.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Profound hyperventilation and development of periodic breathing during exceptional orthostatic stress in a 21-year-old man. Donnelly, J., Lucas, SJ., Thomas, KN., et al.[2011]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11973564/

Carbon dioxide for neurogenic orthostatic hypotension in ... In this proof-of-concept study, we tested the hypothesis that increased inspired CO 2 increases standing blood pressure in patients with nOH.

2. clinicaltrials.gov clinicaltrials.gov/study/NCT05295810

NCT05295810 | Hypercapnia in Orthostatic Hypotension This is a proof-of-concept study to evaluate hypercapnia as a novel therapeutic intervention to improve blood pressure and orthostatic tolerance in male and ...

3. centerwatch.com centerwatch.com/clinical-trials/listings/NCT06751888/controlled-co2-inhalation-in-noh

Controlled CO2 Inhalation in NOH | Clinical Research Trial ... This study focuses on neurogenic orthostatic hypotension (nOH), which is a disorder characterized by an abnormal drop in blood pressure (BP) ...

4. withpower.com withpower.com/trial/carbon-dioxide-breathing-for-orthostatic-hypotension-6fe05

Carbon Dioxide Breathing for Orthostatic Hypotension Trial Overview The study tests if breathing in higher levels of carbon dioxide (Sequential Gas Delivery) can help manage low blood pressure when standing in ...

5. researchgate.net researchgate.net/publication/384696618_Carbon_dioxide_for_neurogenic_orthostatic_hypotension_in_adults_a_novel_therapy

Carbon dioxide for neurogenic orthostatic hypotension in ... Random-effects meta-analysis was used to pool the outcome measures across studies. Results: Seven trials were included in the efficacy ...