[Postoperative cerebral edema. Physiopathology of the edema and medical therapy]

Cerebral edema complicates many neurosurgical conditions, such as head injuries, neoplasms and infections, and is the direct result of operative trauma. The recognition and the treatment of brain edema are of great practical importance, particularly in those conditions leading to brain herniations and/or intracranial hypertension. Brain edema can be distinguished into two major categories, based on the integrity of the blood brain-barrier (BBB). With intact BBB edema, the crucial pathogenic event is related to disturbances of cellular metabolism and ionic transport. All the cellular elements of brain may undergo swelling, with a concomitant reduction of the extracellular-fluid space of the brain. Open BBB edema, the most common form of brain edema, is characterized by increased permeability of the brain endothelial cells. Brain edema results from the oncotic forces generated from a serum protein influx into the nervous tissue, and edema fluid accumulates primarily in the extracellular space. The non-operative management of brain edema requires attention to the causes that have induced brain edema. Specific pharmacologic therapy with corticosteroids, hyperosmolar agents and furosemide or acetazolamide depend upon accurate assessment of BBB integrity.