Neuro - Neurological Disorders Flashcards
What is primary damage in head injuries
initial damage, direct injuries
result of a force applied to the head
tissue and vascular damage
What is secondary damage in head injuries
Result of hypoxia & decreased perfusion, cerebral edema, infection, hemorrhage
Brain’s response - swelling and decreased perfusion –> hypoxia –> swelling –> decreased perfusion
Initial response to bruising
vasodilation and increased blood flow to the are of injury
pressure surrounding injury site
Increased intracerebral pressure –> decreased blood flow
edema develops over a period of hours (late sign)
How does a normal functioning brain work
adjust blood flow to your needs
the O2 and CO2 levels in the blood and cerebrospinal fluid (chemoreceptors) will base how It functions
what will decreased level of CO2 do?
will cause hypoventilation, then cerebral vasoconstriction and cerebral ischemia (hypoxia)
what will increased level of CO2 do?
will cause hyperventilation, vasodilation and edema (hypoxia)
Normal intracranial pressure
5-15mmHg
Pressure inside of brain is a result of what?
brain tissues, blood and CSF
ICP
intracranial pressure
CPP
Cerebral Perfusion Pressure
what is CPP
pressure needed to maintain blood flow to the brain (70-80 MM HG), no less than 60
MAP
Mean Arterial Pressure (70-100 mmHg) < 60 deadly to organs
what’s the equation for CPP
CPP= MAP - ICP
when does blood flow stop?
when ICP = MAP
what are early sings of ICP
CSF shifts to spinal cavity
decrease cerebral blood flow
effective for small periods time until hypoxic
hypoxia triggers vasodilation in brain (attempt to improve blood supply) –> adds fluid volume
B/c of ^ ICP is elevated before sings are apparent
