the study was halted after the first interim analysis as there were significantly more patients who recovered at one month in the control arm

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.

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