Head Injury: part 3

Head Injury: part 3

ANATOMY AND PHYSIOLOGY

E
Cerebral perfusion pressure (CPP) = Mean arterial pressure - ICP.
Maintenance of cerebral perfusion is essential in the management of patients with severe closed head injury. Normal cerebral blood flow (CBF) is approximately 50 mL/100 g brain/minute. CBF <20 mL/100 g brain/minute represents cerebral ischemia, and cell death occurs at approximately 5 mL/100 g brain/minute. In addition to cerebral ischemia in response to injury, the injured brain loses its ability to autoregulate blood flow, increasing susceptibility of the injured brain to further ischemia. The generally acceptable range during active therapy in traumatic brain injury is CPP >60 to 70 mmHg.
II.
TBIs are categorized as mild (80%), moderate (10%), or severe (10%), depending on the level of neurologic dysfunction at the time of initial evaluation. Determination of the Glasgow Coma Scale (GCS) score as early as possible and then serially
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is essential. Loss of consciousness (LOC) is an important indicator of TBI. Classification of TBI is based on the GCS