UMEM Educational Pearls

AGE occurs when gas bubbles enter arteries or veins; AGE may cause clinical symptoms even with very small volumes of air. 

Air enters the circulatory system via:

· Barotrauma – Alveolar injury allows air to enter systemic bloodstream; occurs in divers following rapid ascent after breath holding, during mechanical ventilation, chest tube placement, or bronchoscopy

· Decompression sickness – Dissolved gas precipitates out of bloodstream as bubbles; typically following scuba diving without appropriate time to ascend or prolonged flying in unpressurized aircrafts

· Direct injection of air into arterial or venous circulation – Examples include accidental IV injection of air, needle biopsy of lung, or aspiration of air during central line placement

Serious clinical manifestations include:

· Neurologic changes - loss of consciousness, confusion, or focal neurological deficits

· Hemodynamic changes – hypotension, arrhythmias, cardiac ischemia, or cardiac arrest.

· Respiratory changes – obstruction of pulmonary circulation, pulmonary edema, or hypoxemia

Treatment:

· Strict attention to ABC’s using high-flow O2.

· Keep head of bed elevated to minimize/reduce cerebral edema.

· Hyperbaric Oxygen (HBO) therapy is recommended for neurological manifestations or cardiovascular instability. Good outcomes associated with shorter intervals from air embolism to HBO. Typically only 1 to 2 treatments are needed; occasionally additional treatments are necessary.

References

Follow me on Twitter (@criticalcarenow) or Google+ (+haney mallemat)