Hyperbaric Oxygen Therapy for Comatose Patients With Acute Carbon Monoxide Poisoning

This study has been terminated.
(the study was halted after the first interim analysis as there were significantly more patients who recovered at one month in the control arm)
Assistance Publique - Hôpitaux de Paris
Information provided by:
University of Versailles
ClinicalTrials.gov Identifier:
First received: April 5, 2010
Last updated: April 7, 2010
Last verified: April 2010

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.

Condition Intervention Phase
Carbon Monoxide Poisoning
Other: Hyperbaric oxygen therapy
Other: hyperbaric oxygen therapy
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Phase 3 Study of Hyperbaric Oxygen Therapy for Comatose Patients With Acute Domestic Carbon Monoxide Poisoning

Resource links provided by NLM:

Further study details as provided by University of Versailles:

Primary Outcome Measures:
  • complete recovery [ Time Frame: at one month ] [ Designated as safety issue: No ]
    Complete recovery was defined as an absence of symptoms reported on the self-assessment questionnaire with a normal physical exam (including normal neuropsychological functions).

Secondary Outcome Measures:
  • persistent neurological sequels [ Time Frame: at one month ] [ Designated as safety issue: Yes ]
    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.

  • delayed neurological sequels [ Time Frame: at one month ] [ Designated as safety issue: Yes ]
    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.

  • the difference in carboxyhemoglobin levels before/after treatment completion [ Time Frame: at 12 hours from randomization ] [ Designated as safety issue: No ]
    the difference between serum levels of carboxyhemoglobin at baseline and those recorded immedaitely after study treatment completion

  • serious adverse events [ Time Frame: at one month ] [ Designated as safety issue: Yes ]
    any complication of hyperbaric oxygen therapy

Enrollment: 170
Study Start Date: October 1989
Study Completion Date: February 2000
Primary Completion Date: January 2000 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: One HBO session
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
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
Experimental: 2 HBO sessions
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
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


Ages Eligible for Study:   15 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

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
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01099995

Raymond Poincaré Hospital
GArches, France, 92380
Sponsors and Collaborators
University of Versailles
Assistance Publique - Hôpitaux de Paris
Study Chair: Djillali Annane, MD AP-HP
Principal Investigator: Jean Claude Raphael AP-HP
  More Information

No publications provided

Responsible Party: Christophe Misse, DRRC AP-HP
ClinicalTrials.gov Identifier: NCT01099995     History of Changes
Other Study ID Numbers: CO89-2
Study First Received: April 5, 2010
Last Updated: April 7, 2010
Health Authority: France: Direction Générale de la Santé

Keywords provided by University of Versailles:
domestic accident
carbon monoxide
acute domestic carbon monoxide poisoning

Additional relevant MeSH terms:
Carbon Monoxide Poisoning
Chemically-Induced Disorders
Gas Poisoning
Carbon Monoxide
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Pharmacologic Actions
Physiological Effects of Drugs

ClinicalTrials.gov processed this record on March 26, 2015