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Controlled CO2 Inhalation in NOH

Controlled CO2 Inhalation to Increase Blood Pressure in Neurogenic Orthostatic Hypotension: a Proof-of-Concept Novel Therapy Study

Status
Not yet recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06751888
Acronym
CO2-nOH
Enrollment
28
Registered
2024-12-30
Start date
2025-05-01
Completion date
2028-12-31
Last updated
2024-12-30

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Neurogenic Orthostatic Hypotension

Keywords

Neurogenic Orthostatic Hypotension, Autonomic, Cardiovascular, Therapies, Quality-of-life, Symptom-management, Novel

Brief summary

This study focuses on neurogenic orthostatic hypotension (nOH), which is a disorder characterized by an abnormal drop in blood pressure (BP) within 3-minutes of standing. Patients with nOH experience debilitating symptoms including light-headedness, falls, and fainting. Patients often struggle with day-to-day tasks that require standing, with a reduced quality-of-life. Current therapies for nOH have limited effectiveness and unwanted side effects. Our lab has found that raising blood CO2 levels (hypercapnia) in the lab increases BP when standing in patients with nOH. We now aim to test the CarboHaler, an exogenous controlled CO2 delivery device, in this study to see if increasing CO2 levels through controlled CO2 inhalation can improve BP and reduce symptoms in patients with nOH when standing up. On the study day, participants will undergo two Head-up Tilt (HUT; upright) tests with different breathing protocols: one with and one without exogenous CO2 delivery provided by a CO2 inhalational device. We will record heart rate, blood pressure, and breathing parameters. We will also assess upright symptoms using the Vanderbilt Orthostatic Symptoms Score. Our primary outcome is the magnitude of the change in systolic BP from lying down to standing, which will be compared with and without exogenous CO2 delivery. We hypothesize that exogenous CO2 delivery provided by a CO2 inhalational device will raise CO2 enough to increase standing BP, which could reduce the debilitating symptoms experienced by patients with nOH. We hope that these data will support future clinical trials, with the long-term goal of creating a simple, low-cost treatment for increasing quality-of-life for patients with nOH.

Interventions

OTHERControlled CO2 delivery

The use of a controlled CO2 delivery offers a straightforward way to increase arterial CO2. Controlled CO2 inhalation may offer a novel hemodynamic therapy for patients with Neurogenic Orthostatic Hypotension

DEVICEControlled CO2 delivery (Sham)

For this intervention, we will be using this device set at 0% CO2 for our sham comparison.

Sponsors

University of Calgary
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
SINGLE (Subject)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

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

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

Design outcomes

Primary

MeasureTime frameDescription
Magnitude of the systolic blood pressure (SBP) responseStart of in-lab study day to the end of the in-lab study dayThe primary outcome measures will be the magnitude of the systolic blood pressure (SBP) response (ΔSBP = Head Up Tilt - Supine) during 0% CO2 vs. Controlled CO2 inhalation.

Secondary

MeasureTime frameDescription
Change in Cerebral Blood Flow (ΔCBFv)Start of in-lab study day to the end of the in-lab study daySecondary outcome measures will be the change in Cerebral Blood Flow (ΔCBFv) for each arm of the study.
Change in Vanderbilt Orthostatic Symptom Scores (ΔVOSS)Start of in-lab study day to the end of the in-lab study daySecondary outcome measures will be the change in Vanderbilt Orthostatic Symptom Scores (ΔVOSS) for each arm of the study.

Countries

Canada

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026