NCT04258774

The Effect of Respiratory Challenge on the BOLD Signal

ENROLLING BY INVITATION NA Last updated 16 January 2026

What this trial tests

NA trial testing Carbon Dioxide in Hypoxia, Brain in 48 participants. Enrolling by invitation.

Timeline

29 January 2020

Primary endpoint
31 December 2027

31 December 2027

Quick facts

Lead sponsor	Washington University School of Medicine
Phase	NA
Status	ENROLLING BY INVITATION
Study type	INTERVENTIONAL
Allocation	non randomized
Design	parallel
Masking	none
Primary purpose	other
Enrollment	48
Start date	29 January 2020
Primary completion	31 December 2027
Estimated completion	31 December 2027
Sites	1 location across United States

Drugs / interventions tested

• Carbon Dioxide (CARBON DIOXIDE) — full drug profile →

Conditions studied

• Hypoxia, Brain — all drugs for Hypoxia, Brain →
• Hyperoxia — all drugs for Hyperoxia →
• Hypercapnia — all drugs for Hypercapnia →
• Hypocapnia — all drugs for Hypocapnia →

Sponsor

Washington University School of Medicine

Who can join

18 and older, any sex, with Hypoxia, Brain or Hyperoxia. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

The purpose of this research study is to better understand how blood flow and metabolism are different between normal controls and patients with disease.

The investigators will examine brain blood flow and metabolism using magnetic resonance imaging (MRI). The brain's blood vessels expand and constrict to regulate blood flow based on the brain's needs. The amount of expanding and contracting the blood vessels can do varies by age. The brain's blood flow changes in small ways during everyday activities, such as normal brain growth, exercise, or deep concentration. Significant illness or physiologic stress may increase the brain's metabolic demand or cause other bigger changes in blood flow. If blood vessels are not able to expand to give more blood flow when metabolic demand is high, the brain may not get all of the oxygen it needs. In less extreme circumstances, not having as much oxygen as it wants may cause the brain to grow and develop more slowly than it should.

One way to test the ability of the blood vessels to expand is by measuring blood flow while breathing in carbon dioxide (CO2). CO2 causes blood vessels in the brain to dilate without increasing brain metabolism. The study team will use a special mask to control the amount of oxygen and carbon dioxide patients breath in so that we can study how their brain reacts to these changes. This device designed to simulate carbon dioxide levels achieved by a breath-hold and target the concentration of carbon dioxide in the blood in breathing patients. The device captures exhaled gas and provides an admixture of fresh gas and neutral/expired gas to target different carbon dioxide levels while maintaining a fixed oxygen level. The study team will obtain MRI images of the brain while the subjects are breathing air controlled by the device.

Publications & conference data

No peer-reviewed publications indexed yet for this trial.