Controlled CO2 Inhalation in NOH

Condition(s) studied

Investigational drug(s) / intervention(s)

Controlled 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

Controlled CO2 delivery (Sham): For this intervention, we will be using this device set at 0% CO2 for our sham comparison.

Study 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.

Eligibility

Primary outcome measure(s)

• Magnitude of the systolic blood pressure (SBP) response — Start of in-lab study day to the end of the in-lab study day
  The 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.

Trial sites (1)

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