Ducasse
Hyperbaric oxygenation was associated with more rapid clinical recovery in non-comatose patients with carbon monoxide poisoning. Clinical Bottom Line: 1. Early hyperbaric oxygen treatment results in a significant reduction in those with clinical impairment at 2 and 12 hours.
Appraised by: Mike Bennett, Dept. of Diving and Hyperbaric Medicine, Prince of Wales Hospital Sydney; Tuesday, 24 November, 1998
Clinical Scenario: Non-comatose patient with carbon monoxide intoxication and presenting to hospital within 2 hours. Three-part Question: In non-comatose patients suffering with carbon monoxide intoxication, does the application of hyperbaric oxygen, compared to a normobaric oxygen regime, result in any improvement in neurological outcome? Search Terms: Hyperbaric oxygenation, carbon monoxide poisoning.
The Study: Single-blinded randomised controlled trial with intention-to-treat. Presenting within 2 hours of exposure, less than 12 hours exposure, Glasgow Coma Score of 12 or more and not pregnant. Control group (N = 13; 13 analysed): Oxygen at 1ATA for 6 hours, then 0.5ATA for 6 hours in the ICU. Experimental group (N = 13; 13 analysed): Oxygen at 2.5ATA for 2 hours in a hyperbaric chamber, then at 1ATA for 4 hours and 0.5ATA for 6 hours.
The Evidence:
| Outcome | Time to Outcome | NBO group | HBO group | Relative risk reduction | Absolute risk reduction | Number needed to treat |
| Clinical abnormalities | 2 hours | 0.692 | 0.154 | 78% | 0.54 | 2 |
| 95% CI | 32% to 100% | 0.22 to 0.86 | 1 to 5 | |||
| Clinical abnormalities | 12 hours | 0.385 | 0 | 100% | 0.39 | 3 |
| 95% CI | 0.12 to 0.65 | 2 to 8 |
Comments: 1. Patients and staff not blinded to treatment. 2. No information on longer-term outcomes. No apparent neurological differences. 3. Clinical abnormalities included headache, reflex impairment, asthenia and pulmonary oedema.
- Expiry date: April 2020
- References:
1. Ducasse JL, Cesis P, Marc-Vergnes JP. Non-comatose patients with acute carbon monoxide poisoning: hyperbaric or normobaric oxygenation? Undersea Hyperbaric Medicine 1995;22:9-15. 2. Ducasse JL, Izard PH, Celcis P, Leclercq Ch et al. Moderate carbon monoxide poisoning: hyperbaric or normobaric oxygenation? In: Bakker DJ, Schmutz J eds. Hyperbaric Medicine Proceedings, 2nd Swiss Symposium on Hyperbaric Medicine. Basel, Switzerland: Foundation for Hyperbaric Medicine 1990:289-297.
