Gas embolism is when air or other gases within the bloodstream form bubbles and these bubbles block blood vessels.
The commonest example in our work is that of arterial gas embolism, which we see in divers.
Gas embolism can occur for other reasons. It can be an unfortunate and unintended complication of a medical procedure. For example, chest surgery, chest drain insertion or insertion of large lines into big veins for administration of fluids or drugs in hospital.
Both groups of patients are treated with Hyperbaric Oxygen (HBO) at our chamber under discussion with our duty doctor. The course of treatment varies depending on the individual case.
The vast majority of individuals with gas embolism that we treat are divers with arterial gas embolism (AGE), following pulmonary barotrauma during a dive. The vast majority of individuals with gas embolism that we treat are divers with arterial gas embolism (AGE), following pulmonary barotrauma during a dive. Of course arterial or venous gas embolism can occur for many other reasons, mostly iatrogenic.
AGE can be seen as a result of
- Mechanical ventilation
- Penetrating chest trauma
- Chest tube insertion
The venous system is also often exposed to the possibility of excess gas being injected iatrogenically as well. For example,
- Accidental IV injection
- Bypass accidents
- During haemodialysis
- CV line insertion/disconnection
- Surgical wounds higher than the heart, e.g. sitting craniotomy.
An individual can tolerate up to 20ml/min IV of gas, whereas volumes tolerated directly into arterial system are much lower. There is limited data on the exact volume.
Air within the circulation will create different pathology depending on its location and volume. Air within the heart can lead to a “vapour lock” resulting in circulatory compromise thus hypotension and cardiac arrest. It could also cause arrhythmias and or ischaemia if passes into the cardiac vessels.
Bubbles may pass into the cerebral circulation and manifest as general reduction in GCS or focal neurology depending on their location.Treatment entails up to 10 sessions of HBO over a 2 week period subject to response to treatment.
Further information regarding Referral and Funding can be found here.
The Royal College of Surgeons of Edinburgh
Diploma in Remote and Offshore Medicine
Blanc P. Boussuges A, Henriette K, etal
“Iatrogenic cerebral air embolism: importance of an early hyperbaric oxygenation.”
Intensive Care Med
Epub 2002 Mar 21
“Hyperbaric oxygen treatment for air or gas emobolism”
Undersea Hyperb Med
2014 Mar-Apr; 41(2):159-66