One vs. Three Hyperbaric Oxygen Treatments for Acute Carbon Monoxide Poisoning

Study Overview
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Brief Summary
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This randomized trial will investigate important clinical outcomes of patients with acute carbon monoxide poisoning randomized to receive either one or three hyperbaric oxygen treatments.

Detailed Description
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All patients presenting with acute carbon monoxide poisoning will receive one hyperbaric oxygen treatment (barring contraindications for hyperbaric oxygen therapy). After this treatment, eligible patients who provide consent will be randomly allocated to receive two sham sessions, or two additional hyperbaric oxygen sessions administered in a double-blind fashion. Outcome measures will be administered at 6 weeks and 6 months.

Official Title
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Randomized Trial of One Versus Three Hyperbaric Oxygen Treatments for Acute CO Poisoning

Conditions
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Carbon Monoxide Poisoning

Intervention / Treatment
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* Combination Product: Hyperbaric Oxygen (HBO2) - 3 sessions
* Combination Product: Hyperbaric Oxygen (HBO2) - 1 session


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Symptomatic CO poisoning (headache, nausea, vomiting, dizziness, fatigue, muscle aches, slowed mentation, confusion, or loss of consciousness). Carboxyhemoglobin (COHb) levels > 10% or confirmation of poisoning with ambient levels > 50 ppm in a patient with symptoms compatible with CO poisoning and no other reasonable explanation for their signs and symptoms. Less than 24 hours from removal from the source of CO exposure and study enrollment. Accidental poisoning Exclusion Criteria: Pregnancy Age < 18 years or > 79 years Complication during first hyperbaric oxygen session precluding subsequent hyperbaric oxygen. Intentional CO poisoning Unable to obtain informed consent Moribund patient Concomitant smoke inhalation with cyanide poisoning Bleomycin use within two weeks of study enrollment Intracardiac defibrillator that cannot be deactivated Non-English speaking Unlikely to return at 6 weeks History of central nervous system (CNS) disease (i.e., Alzheimer's, Parkinson's, dementia, demyelinating disease (MS), etc.) History of prior brain injury (i.e., stroke, traumatic brain injury) Presence of chronic debilitating disease likely to result in death within 12 months (i.e., kidney failure on dialysis, heart failure) Subject has a significant medical condition or conditions that would interfere with the treatment, safety, or compliance with the protocol. Intubated subjects Subjects requiring greater than 50% oxygen by non-rebreather facemask or exhibiting evidence of respiratory compromise or heart failure Subjects who, in the opinion of the investigator, are unable to comply with the requirements of the study or are unsuitable for any reason. The investigator and the Sponsor, prior to enrolling the subject on a case-by-case basis, must approve and document any waiver of these inclusion and exclusion criteria.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 79 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Hyperbaric Oxygen (HBO2) - 3 sessions<br>Subjects undergo 3 hyperbaric oxygen sessions within 24 hours following carbon monoxide poisoning. | Combination Product: Hyperbaric Oxygen (HBO2) - 3 sessions<br>* Before patients are offered an opportunity to participate in this study, they will receive a single hyperbaric oxygen session. During the first session, hyperbaric oxygen will be administered at 3.0 atmospheres absolute (atm abs) for 25 minutes breathing oxygen, 5 minutes air breathing, 25 minutes oxygen breathing, 5 minutes air breathing, pressure reduced to 2.0 atm abs for 30 minutes breathing oxygen, 5 minutes air breathing, and 30 minutes oxygen breathing. For the second and third hyperbaric oxygen sessions, the subject will breathe 100% oxygen delivered at 2 atm abs for 90 minutes with two 5-minute air breathing periods.<br>* Other names: HBOT;|
| Sham Comparator: Hyperbaric Oxygen (HBO2) - 1 session<br>Subjects undergo 1 hyperbaric oxygen session and then 2 sham chamber sessions within 24 hours of carbon monoxide poisoning. | Combination Product: Hyperbaric Oxygen (HBO2) - 1 session<br>* During the first session, hyperbaric oxygen will be administered at 3.0 atmospheres absolute (atm abs) for 25 minutes breathing oxygen, 5 minutes air breathing, 25 minutes oxygen breathing, 5 minutes air breathing, pressure reduced to 2.0 atm abs for 30 minutes breathing oxygen, 5 minutes air breathing, and 30 minutes oxygen breathing. The second and third chamber sessions are sham sessions: room air delivered at 1.0 atmospheres absolute for 90 minutes with two sham 5-minute air breathing periods.<br>* Other names: HBO2;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 6-week cognitive sequelae | Presence of cognitive sequelae at 6-week follow-up | 6 weeks after poisoning | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neurological examination | Presence of neurological abnormalities | 6 weeks and 6 months after poisoning | 
| Depression, anxiety or post-traumatic stress syndrome | Presence of depression, anxiety, or PTSD symptoms | 6 weeks and 6 months after poisoning | 
| Vocational assessment | Results of vocational testing | 6 weeks and 6 months after poisoning | 
| Patient self-reports of CO-related problems | Participant-reported outcome | 6 weeks and 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Carbon monoxide poisoning, Hyperbaric oxygen therapy, Randomized controlled trial, Clinical investigation