RESUMO
An 25-year-old man was buried by an avalanche during off-slope skiing. He was rescued by his companions and resuscitated by mouth-to-mouth ventilation. The emergency physician from a helicopter based emergency medical service placed two venous lines in both external jugular veins and secured the airway with a tracheal tube. When transferred to the emergency department an additional central venous catheter was inserted via his right femoral vein. The subsequent computed tomography scan revealed several small air bubbles adjacent to the endothelium of the brachiocephalic vein. In an experimental setting, it was shown that air could enter the circulation via a central venous catheter within a few seconds, but measured values of embolising air were smaller than the calculated values when applying the law of Hagen-Poiseuille. Nevertheless, it is important to keep the lumens of a central venous catheter filled with saline before any manipulation in order to prevent or attenuate venous air embolism.
RESUMO
A bench study was performed to investigate the potential of air bubbles entering a central vein via a central venous catheter to ascend retrograde to the brain. The results support the hypothesis that air bubbles may rise retrograde against the venous blood flow, depending on bubble size, central vein diameter and cardiac output. A review of radiological findings in published case reports indicates that the occurrence of retrograde cerebral air embolism is underestimated.
