Volume of Air Required for a Lethal Air Embolism

 

Factor	Comment
presence of serious cardiorespiratory comorbid condition(s)	a person with comorbid cardiopulmonary condition may die from a smaller air embolus than a healthy young adult
location of air embolus	an air embolus lodging in a coronary artery or cerebral artery may be quite small
total volume	a larger air embolus is more likely to be lethal
speed of delivery	a single large bolus is more likely to be lethal than a slow, intermittent input of air

 

Volume of a venous air embolus large enough to be lethal:

(1) 300 mL in the adult

(2) 200 mL in an adult with comorbid conditions

(3) 3 to 5 mL per kg

 

Problems with determining a lethal volume of an air embolus:

(1) the total volume injected is not known with certainty

(2) the total volume may be difficult to determine at autopsy, especially if it was unsuspected

 

The volume of air required for a lethal embolism in the arterial circulation can be quite small (2-3 ml) if the embolus lodges in a vulnerable site of a coronary or cerebral artery.

 

A total body CT scan may be necessary to determine the total volume of air emboli. The diagnosis of air emboli as the cause of death requires exclusion of other causes.