Pediatric Terrorism and Disaster Preparedness: A ... - PHE Home

additional morbidity in the nature of blindness (occlusion of retinal arteries) and ischemia
of end organs. The ultimate clinical result depends on the site of embolization. Signs and
symptoms that suggest arterial air embolization include the following:
• Air bubbles in retinal vessels.
• Blindness.
• Chest pain.
• Arrhythmia.
• Myocardial ischemia.
• Focal neurologic signs.
• Seizures.
• Loss of consciousness.
• Vertigo.
• Livedo reticularis.
• Tongue blanching.
Air emboli pose a challenge in emergency management of blast victims. Air emboli are
not only difficult to diagnose, but also have a clinical presentation similar to that of other
more familiar clinical entities. For example, myocardial ischemia, which is usually easily
recognized, is most likely to be secondary to coronary vessel embolization (versus the
traditional mechanisms of ischemia) in victims with blast lung injury. Management of
these patients should focus on halting the passage of air. However, in patients exhibiting
a change in their mental status, more common traumatic causes (e.g., intracranial
hemorrhage from blunt head injury) should be addressed first, before focusing on
embolization.
Air emboli can be confirmed by direct visualization of air bubbles or disrupted air
passages via echocardiography, transcranial Doppler, CT scan, or bronchoscopy.
Unfortunately, there are no data on the sensitivity of these techniques in detecting emboli
in blast victims. Transesophageal echocardiography can detect gas bubbles as small as
2 µm, but its availability is limited. Sudden circulatory or neurologic collapse, especially
if PPV has been started, combined with a high index of suspicion, is enough to make the
diagnosis of air embolization until proved otherwise. Other suggestive clinical findings
include possible evidence of bubbles in retinal vessels, aspiration of air from arterial
lines, or marbling of the skin or tongue.
In conventional penetrating and blunt lung injuries, management of massive air
embolization involves thoracotomy on the affected side to stop the passage of air. Based
on this experience, management of air embolization in blast lung injury has also been
primarily surgical. However, in blast lung injury, identifying the source of emboli may be
difficult, since both lungs or multiple sites may be involved. Temporarily placing patients
in specific positions to trap air bubbles anatomically (to prevent them from entering the
circulation) has been suggested. However, there is no single maneuver that prevents air
from entering both the arterial and venous circulation simultaneously. Despite the lack of
data, placing the patient in a modified left decubitus position (more toward prone) or
prone position is thought to be the most anatomically logical alternative. These positions
place the coronary ostia in the lowest position in the body and the left atrium in the
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