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Air or Gas


Hyperbaric Oxygen Therapy


"Treating the 14 conditions covered by OHIP"

Ontario HBOT

What is an Embolism?
An embolism is a moving obstruction in the bloodstream. An air or gas bubble can obstruct blood flow and damage the brain, the heart, or other vital organs and tissues, resulting in pain or death. Permanent disabilities may include vision impairment, paralysis, and respiratory problems.

Gas bubbles in veins travel to the heart and then to the lungs. If the bubbles are small, such as those introduced inadvertently through intraveneous fluid lines, they are usually stopped at the lungs and rarely produce symptoms. Larger gas bubbles in veins can lodge in the heart, lungs, or brain and cause damage.
Arterial Gas Embolism (AGE)
Arterial gas embolisms (AGE) can be much more damaging because they can directly obstruct the flow of blood to body tissue. Even small arterial gas obstructions can cause death by stopping the flow of blood to the heart, brain, and lungs.
Treatment with HBOT
Hyperbaric oxygen therapy (HBOT) has been an established treatment for both diving-related and iatrogenic AGE for many years. Although there are no randomized controlled trials demonstrating the positive effect of HBOT, there are numerous case reports and case series and also sound mechanistic principles that support its use in AGE. The high oxygen tension promotes the resorption of nitrogen from the bubble and the elevated ambient pressure reduces the size of the bubbles in accordance with Boyle's law.
At 282 kPa (a conventional HBOT treatment pressure), spherical gas bubble diameter will be reduced to 82% with a resulting 45% decrease in volume, such that bubble passage through the microcirculation and resolution of embolic phenomena may occur.
How do I Qualify for OHIP Coverage?

In order to qualify for OHIP covered hyperbaric oxygen therapy for an arterial gas embolism (AGE), supporting documentation must be provided. Typical tests/procedures that occur to determine whether an individual has an AGE are:  

  • Chest X-Ray: gas bubbles can sometimes show up on X-rays

  • Stethoscope: to the trained ear, a “millwheel” murmur can sometimes be detected

  • Change in gases: if the patient is under anesthetic and still being monitored, the anesthesiologist may be able to detect a decrease in the amount of carbon dioxide released at the end of an expiration

  • Doppler ultrasonography: this non-invasive procedure estimates blood flow through the vessels by bouncing high-frequency sound waves off circulating red blood cells. This procedure is often used during operations with a high risk of air embolism

  • Transesophageal echocardiography: this method uses sound to produce a highly detailed image of the heart and the vessels that lead to it.


A referral from a physician or specialist is preferred, however it is not absolutely necessary. Our medical director will look over all supporting documentation, and make the ultimate decision for qualification.

Additional Literature
The following documents are sourced from respected medical journals regarding Arterial Gas Embolisms (AGE) and Hyperbaric Oxygen Therapy (HBOT). 
Please click on the icon to open the PDF in your browser window. If you would like to download the PDF to your computer, right click on the icon and select "save linked file as". 
The British Journal of Anaesthesia
Volume 103, Issue 2, Pages 306–307​
Published: August 2009
The Journal of Thoracic & Cardiovascular Surgery
Volume 117, Issue 4, Pages 818–821
Published: April 1999
The British Journal of Anaesthesia
Volume 72, Issue 1, Pages 129–130
Published: December 2016
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