Poor outcome after hypoxia-ischemia in newborns is associated with physiological abnormalities during early recovery - Possible relevance to secondary brain injury after head trauma in infants

"Secondary hypoxia/ischemia" (i.e. regional impairment of oxygen and substr ate delivery) results in secondary deterioration after traumatic brain inju ry in adults as well as in children and infants. However, detailed analysis regarding critical physiological abnormalities resulting from hppoxia/isch emia in the immature brain, e.g. acid-base-status, serum glucose levels and brain temperature, and their influence on outcome, are only available from non-traumatic experimental models. In recent studies on hypoxic/asphyxic cardiac arrest in neonatal piglets, w e were able to predict short-term outcome using specific physiologic abnorm alities immediately after the insult. Severe acidosis, low serum glucose le vels and fever after resuscitation were associated with an adverse neurolog ic recovery one day after the insult. The occurrence of clinically apparent seizure activity during later recovery increased mortality (epileptic stat e), and survivors had greater neocortical and striatal brain damage. Brain damage after transient hypoxia/ischemia and "secondary brain injury" after head trauma may have some mechanistic overlap, and these findings on physiological predictors of outcome may also apply to pathologic conditions in the post-traumatic immature brain. Evaluation of data from other models of brain injury will be important to develop candidate treatment strategie s for head-injured infants and children and may help to initiate specific s tudies about the possible role of these physiological predictors of brain d amage in the traumatically injured immature brain.