Air Embolism
(Review in Anesthesiology 1999;90(2):564)
if patient decompensates just after being placed on mech vent, consider this dx
caused by gradient of low pressure pulmonary venous system (hypovolemia) and/or increased airway pressure (PPV, cough, tension pneumo)
2 cc of air injected into the cerebral circ can be fatal
1 cc of air in the pulm vein can cause cardiac arrest
injuries close to the hilium yield the highest risk b/c the pulm vein (low pressure) is close to the large airways
Probe positive PFO can allow conduit from venous air embolism
paradoxical embolism can also occur in ARDS, pulm htn,
ability of lungs to function as filter is exceeded at 0.35 cc of air per kg per minute
blast injury can cause massive air embolism
hemoptysis with circulatory and CNS dysfunction is sufficient for provisional diagnosis
fundoscopic exam may reveal air in retinal vessels
TEE can detect extremely small bubbles
tympanic membrane should rupture if lung ruptures in blast injury
spont vent is preferred, lung isolation if only one lung injured and ppv is necessary
thoracotmy with hilar clamping has been used
hyperbarics for SAE
HFOV is preferred mode if there is bronchopleural fistula
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