Hyperbaric Oxygen Therapy for Carbon Monoxide Poisoning

Carbon monoxide (CO) binds haemoglobin with an affinity over 200 times that of oxygen, forming carboxyhaemoglobin and causing tissue hypoxia despite normal arterial oxygen tension. Hyperbaric oxygen therapy (HBOT) delivers 100 per cent oxygen at elevated ambient pressures, thereby accelerating CO dissociation from haemoglobin, enhancing dissolved oxygen content in plasma and reducing lipid peroxidation. Over the past decades, HBOT has become a mainstay of treatment for moderate to severe CO poisoning, with the aim of reducing acute neurological injury and preventing delayed neuropsychological sequelae. Protocols typically involve multiple sessions at pressures between 2.5 and 3.0 atmospheres absolute, although optimal timing and total number of sessions remain debated. Clinical decision-making balances potential benefits against logistical constraints and risks such as barotrauma and oxygen toxicity. In parallel, mechanistic studies have revealed that CO induces oxidative stress, mitochondrial dysfunction and inflammatory cascades, suggesting that adjunctive antioxidant or cytoprotective strategies may further improve outcomes. Despite widespread adoption of HBOT in many centres, randomised trials have yielded mixed results, fuelled by differences in patient selection, severity grading and end-point definitions. Globally, access to hyperbaric facilities varies markedly, and in resource-limited settings normobaric high-flow oxygen remains the primary intervention. Moving forward, integration of biomarkers for injury stratification, refined pressure-time protocols and combination therapies is expected to refine the therapeutic index of HBOT and guide personalised treatment pathways.

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Hyperbaric Oxygen Therapy for Carbon Monoxide Poisoning publication trend

The graph below shows the total number of articles in hyperbaric oxygen therapy for carbon monoxide poisoning across all publications each year (not limited to Nature Index journals).

Technical terms

Hyperbaric oxygen therapy (HBOT): Medical treatment in which a patient breathes pure oxygen in a pressurised chamber to increase blood and tissue oxygen levels.

Carboxyhaemoglobin: Haemoglobin bound to carbon monoxide, impairing oxygen delivery to tissues.

Reactive oxygen species (ROS): Highly reactive molecules derived from oxygen that can damage cellular components and contribute to oxidative stress.

Neuropsychological sequelae: Delayed cognitive or behavioural impairments that follow an acute neurological insult, such as CO poisoning.

References

1. Long-Term Prognosis of Patients with Carbon Monoxide Poisoning: A Nationwide Cohort Study. PLOS ONE (2014).
2. Carbon monoxide neurotoxicity is triggered by oxidative stress induced by ROS production from three distinct cellular sources. Redox Biology (2023).
3. A synthetic porphyrin as an effective dual antidote against carbon monoxide and cyanide poisoning. Proceedings of the National Academy of Sciences of the United States of America (2023).