Carbon Monoxide Hyperbaric Oxygen With Steroid Therapy (CODex)

April 13, 2026 updated by: University of Nebraska

Trial of Dexamethasone vs Placebo as an Adjunctive Therapy to Hyperbaric Oxygen Treatment HBO in Patients With Acute Carbon Monoxide Poisoning

Hyperbaric Oxygen Therapy (HBO) is routine treatment of carbon monoxide (CO) poisoning to prevent delayed neurological sequelae. This study looking to see if neurologic outcomes are improved with the addition of dexamethasone. CO poisoning can initiate a free radical mediated process that can instigate a demyelinating process resulting in long term neurological sequelae in some, but not all patients. In other demyelinating disorders, steroids are a part of first line treatment. HBO is already used for acute CO poisoning, so this pilot study will try to ascertain if the addition of steroids in concert with each hyperbaric oxygen session will yield improved outcomes.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Hyperbaric Oxygen Therapy (HBO) is routine treatment of carbon monoxide (CO) poisoning to prevent delayed neurological sequelae. This study looking to see if neurologic outcomes are improved with the addition of dexamethasone. CO poisoning can initiate a free radical mediated process that can instigate a demyelinating process resulting in long term neurological sequelae in some, but not all patients. In other demyelinating disorders, steroids are a part of first line treatment. HBO is already used for acute CO poisoning, so this pilot study will try to ascertain if the addition of steroids in concert with each hyperbaric oxygen session will yield improved outcomes.

The control group will receive three HBO treatment sessions plus placebo. The treatment group will receive three HBO treatment sessions plus 10 mg Dexamethasone per day during HBO therapy (minimum of two doses, up to a maximum of five doses if participant stays for longer than three days). After three treatment sessions, the participant will be discharged home barring no other medical complications requiring further hospitalization. In two weeks, participants will return for follow-up testing and evaluation. Continued HBO therapy plus placebo as well as HBO therapy plus steroids for respective group members will be offered if participants are still dealing with CO poisoning sequelae as determined by our outcome measures. In addition, a 6 week and 12 week telephone follow-up will be conducted asking questions regarding memory, emotion, neurologic symptoms.

Study Type

Interventional

Enrollment (Estimated)

20

Phase

  • Phase 2
  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • Nebraska
      • Omaha, Nebraska, United States, 68105
        • Nebraska Medicine, Hyperbaric Medicine Program, Clarkson Tower
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Acute CO poisoning, intentional or non-intentional exposure, receiving HBO treatment during hospitalization
  • Age >18 years
  • Nebraska Medicine admission

Exclusion Criteria:

  • Mechanical ventilation
  • No hospital admission or admission to hospital Critical Care Medicine Service
  • Allergy to dexamethasone
  • Pre-Existing neurological condition confounding outcome determination

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Hyperbaric Oxygen Therapy with Dexamethasone
Participants will be treated with hyperbaric oxygen (HBO) therapy within three days of acute carbon monoxide poisoning. Treatment is a minimum of three inpatient sessions. Participants will also receive 10 mg dexamethasone per day while receiving HBO therapy (minimum of two doses, maximum of five doses if participants' stay is longer than three days). After three treatment sessions, participants will discharge home, barring no other medical complications requiring further hospitalization. In addition, continued HBO therapy plus steroids will be offered if participants are still dealing with CO poisoning sequelae as determined by study outcome measures.
Drug: Dexamethasone
10mg IV Dexamethasone
Other Names:
  • Ozurdex, Maxidex, DexPak 10 day, DexPak 6 Day, LoCort, DoubleDex, ReadySharp dexamethasone, DexPak 13 Day, ZonaCort
Placebo Comparator: Hyperbaric Oxygen Therapy with Placebo (Saline)
Participants will be treated with hyperbaric oxygen (HBO) therapy within three days of acute carbon monoxide poisoning. Treatment is a minimum of three inpatient sessions. Participants will also a saline placebo instead of dexamethasone while receiving HBO therapy. After three treatment sessions, participants will discharge home, barring no other medical complications requiring further hospitalization. In addition, continued HBO therapy plus steroids will be offered if participants are still dealing with CO poisoning sequelae as determined by study outcome measures.
Drug: saline placebo
IV saline bolus
Other Names:
  • nebulized normal saline (NS) placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Montreal Cognitive Assessment (MoCA)
Time Frame: Prior to hospital discharge after HBO therapy is no longer clinically warranted, and post-discharge at 2 weeks, 6 weeks, and 12 weeks.
The Montreal Cognitive Assessment (MoCA) is a rapid screening instrument for mild cognitive dysfunction that assesses different cognitive domains: attention and concentration, executive functions, memory, language, visuo-constructional skills, conceptual thinking, calculations, and orientation. The MoCA will be given in person while inpatient and via phone after discharge. Scored 0-30 Normal Cognitive performance 26 and above Mild impairment 18-25 Moderate impairment 10-17 Severe impairment 0-9
Prior to hospital discharge after HBO therapy is no longer clinically warranted, and post-discharge at 2 weeks, 6 weeks, and 12 weeks.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Memory, Emotion, and Neurologic Symptoms
Time Frame: 6 weeks and 12 weeks post-treatment
Post-treatment phone followup
6 weeks and 12 weeks post-treatment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Nebraska

Investigators

  • Principal Investigator: Jeffrey S Cooper, MD, University of Nebraska

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

July 1, 2026

Primary Completion (Estimated)

July 1, 2027

Study Completion (Estimated)

January 1, 2028

Study Registration Dates

First Submitted

August 22, 2024

First Submitted That Met QC Criteria

August 23, 2024

First Posted (Actual)

August 27, 2024

Study Record Updates

Last Update Posted (Actual)

April 17, 2026

Last Update Submitted That Met QC Criteria

April 13, 2026

Last Verified

October 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 0564-24-FB

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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