Hyperbaric Oxygen Therapy for Comatose Patients With Acute Carbon Monoxide Poisoning

Study Overview
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Brief Summary
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Carbon monoxide poisoning still places a burden on the healthcare system worldwide. While oxygen therapy is the cornerstone treatment, the role and practical modalities of hyperbaric oxygen therapy (HBO) remain controversial. This study aimed at comparing two sessions of HBO at 2 absolute atmosphere and one session of HBO at 2 absolute atmosphere followed by 4 hours of normobaric oxygen therapy in comatose adult victims of acute domestic carbon monoxide poisoning.

Official Title
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Phase 3 Study of Hyperbaric Oxygen Therapy for Comatose Patients With Acute Domestic Carbon Monoxide Poisoning

Conditions
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Carbon Monoxide Poisoning

Intervention / Treatment
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* Other: Hyperbaric oxygen therapy
* Other: hyperbaric oxygen therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients older than 15 years of age admitted for domestic CO poisoning within 12 hours after the end of CO exposure initial coma, regardless of consciousness at hospital admission carboxyhemoglobin level at presentation greater than 10% or 5%, in smokers and non-smokers, respectively Exclusion Criteria: poisoning by more than one compound (e.g., CO plus a drug or CO plus other toxic gases such as those found in fire smoke) suicide attempt pregnancy contraindications to HBO (circulatory collapse or pneumothorax) technical obstacles to HBO non domestic CO poisoning difficulty in determining whether the patient experienced initial loss of consciousness or initial coma consent refusal

Ages Eligible for Study
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Minimum Age: 15 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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: One HBO session<br>hyperbaric oxygen therapy one dive at 2 absolute atmosphere (1-hour plateau) - oxygen was delivered via a full face mask - followed by 4 hours of normobaric oxygen therapy | Other: Hyperbaric oxygen therapy<br>* one dive at 2 absolute atmosphere (1-hour plateau) with 30 min time for compression and decompression - oxygen was delivered via a full face mask at high concentration to achieve a 100% inspired fraction of oxygen or via mechanical ventilation<br>|
| Experimental: 2 HBO sessions<br>Two sessions of hyperbaric oxygen therapy at 2 absolute atmosphere (1-hour plateau) with oxygen delivered via a full face mask at 100% inspired oxygen fraction or via mechanical ventilation | Other: hyperbaric oxygen therapy<br>* two dives at 2 absolute atmosphere (1-hour plateau) with 30 min of compression and 30 min of decompression - oxygen being delivered via a full face mask at 100% inspired oxygen fraction or via mechanical ventilation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| complete recovery | Complete recovery was defined as an absence of symptoms reported on the self-assessment questionnaire with a normal physical exam (including normal neuropsychological functions). | at one month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| persistent neurological sequels | Neurological sequels were considered persistent (PNS) if they were present both at hospital discharge and at one-month evaluation, regardless of the type of manifestation. | at one month | 
| delayed neurological sequels | Delayed neurological sequelae (DNS) were any neurological manifestations that appeared between hospital discharge and one-month evaluation, regardless of their severity. Patients with DNS were those considered fully recovered at hospital discharge but with neurological manifestations at one-month evaluation. | at one month | 
| the difference in carboxyhemoglobin levels before/after treatment completion | the difference between serum levels of carboxyhemoglobin at baseline and those recorded immedaitely after study treatment completion | at 12 hours from randomization | 
| serious adverse events | any complication of hyperbaric oxygen therapy | at one month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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domestic accident, coma, carbon monoxide, intoxication, acute domestic carbon monoxide poisoning