Hyperbaric Oxygen Therapy and Air or Gas Embolism

Air or gas embolism occurs when gas bubbles enter arteries or veins. This results in reduced blood flow and poor oxygen delivery to the affected areas, usually the brain.

If not fatal, gas embolism can result in severe, long-standing and irreversible disabilities. There can be weakness or paralysis in the limbs; vision can be impaired and brain, heart, lung and other organ damage may occur. These outcomes may be permanent and may severely impact quality of life. Maximal medical treatment of the condition is necessary to ensure the best possible degree of recovery.

Hyperbaric oxygen has been shown to reduce the size of bubbles blocking circulation. The increased pressure in the hyperbaric chamber reduces bubble size and drives the remaining gas into physical solution, while the high oxygen pressure washes out inert nitrogen gas from the bubble. When bubbles are smaller or resolved, blood flow resumes. Poorly oxygenated tissues then receive higher levels of oxygen delivery.

Another problem in gas embolism is that vessels obstructed by bubbles may leak fluid into surrounding tissues, resulting in edema (swelling). This can further reduce tissue blood flow. When flow is restored, the local swelling will subside with improvement in circulation and oxygen supply. Finally, the high levels of oxygen provided in the hyperbaric chamber have the potential to immediately restore cellular oxygen levels while blood flow and tissue swelling are being treated.

Hyperbaric oxygen treatment is the primary treatment for gas embolism and a review of reported cases indicates superior outcomes with its use compared to non-recompression treatment.

References:

Source: Hyperbaric Oxygen Therapy: A Committee Report. Undersea and Hyperbaric Medical Society.