Air embolism refers to bubbles in the arterial or venous circulation. Venous bubbles can result from compressed gas diving (such as scuba) but are often filtered through the pulmonary capillary bed. If a large volume of bubbles is noted, they may overwhelm the pulmonary filter and enter the arterial circulation. Arterial gas emboli (AGE) can also result from pulmonary barotrauma or accidental intravenous air injection or some surgical procedures. Symptoms usually occur within seconds to minutes of the event and can include loss of consciousness, confusion, neurological deficits, cardiac arrhythmias, or cardiac arrest.
The treatment of choice is recompression therapy. Gas embolism used to be treated with US Navy Treatment Table 6A, which required a pressure of 6 ATA. The rationale was that the larger volume of gas warranted increased pressure to force bubble redistribution or elimination. No conclusive evidence demonstrates that this offers superior treatment to the US Navy Treatment Table 6 for most cases. However, if complete relief is not achieved after initial recompression, deeper recompression may be needed.