الفهرس 
AnatomyOnly 14 pages are availabe for public view
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Abstract
The CNS is the system first to begin and probably last to complete
its development in human maturation.
It is important to know the physiology of cerebral blood flow and
its autoregulation. In normal infants and children, global CBF is slightly
higher than in adults (65ml/100 g per minute). Regional cerebral
metabolic rate for oxygen (CMRO2) is an important determinant of
regional CBF, because supply is closely linked to demand in both adults
and children. CBF therefore will increase with increased CMRO2, such as
that associated with seizures or fever.
CBF depends on cerebral perfusion pressure, arterial oxygen
(PaO2) and carbon dioxide (PaCO2) tensions which is equal to the mean
arterial pressure (MAP) minus the cerebral venous pressure.
It varies linearly with PaCO2 between 20 and 80 mm Hg, at PaCO2
greater than 80 mm Hg, the cerebral vasculature is maximally dilated, and
sensitivity to further increases in PaCO2 decreases, when PaCO2
decreases below 20 mm Hg, CBF does not decrease further, presumably
because ischemia-induced metabolic changes override the response to
carbon dioxide.
The cerebral vasculature is less sensitive to changes in PaO2
than in adults, it does not increase until PaO2 decreases to less than 50
mm Hg.
The concept of spinal cord perfusion pressure (SCPP) that is equal
to mean arterial pressure minus extrinsic pressure on the cord is clinically
useful because it describes factors that affect the adequacy of spinal
perfusion. Pressures exerted by local extrinsic mechanical compression,
such as tumor, hematoma, spinal venous congestion, and increased
intraspinal fluid pressure, can be important determinants of the SCPP.
SUMMARY
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The choice of the proper anesthetic either inhaled, intravenous or
muscle relaxant should be also taken in consideration according to the
general condition as ICT….etc.
In preoperative evaluation of trauma patients, conscious level must
be assessed according to Glasgow coma scale. Premedication should also
be given carefully. Before induction of anesthesia, the anesthetist must be
oriented by the differences between the infantile and adult airway to pass
the intubation process successfully. Also, monitoring and positioning
should be taken in consideration and how to prevent their complications.
In neurosurgical procedures in infants, each procedure has its main
problem as bleeding in craniostenosis, venous air embolism in the sitting
position, the anesthetist should be very alert and knows how to deal with
it to prevent the complications and how to treat these complications if
happened.