raised ICP, Brain Herniations, haemorrhage Flashcards
effect of ↑ICP on CCP?
↓cerebral perfusion pressure
mortality rate of raised ICP?
20%
what the three brain volumes?
how many mls does each take?
o Brain 1300ml
o CSF 130 ml
o Blood 130 ml
what is Normal ICP?
7-15mmHg
what does ICP stand for?
units?
intracranial pressure
mmHg
how much pressure is Abnormal ICP?
> 15mmHg
how much pressure is pathological ICP?
> 20mmHg
how does standing effect ICP?
decreases ICP
how is CCP calculated?
what does CCP stand for?
MAP – ICP
which hypothesis from Edinburgh describes how brain volumes behave?
and what exactly does this hypothesis state?
Monro Kellie hypothesis
if volume of one of the cranial constituents increases, this must be compensated by a decrease in volume of another
what term is used when there is too much CSF?
hydrocephalus
what pathological thing could increase CSF production?
tumour choroid plexus
why is there a headache with ↑ICP?
brain pushed out –> meninges sensitive to pain pushed –> headache caused
a pt has raised ICP.
how will their the severity of their headaches change during the day, i.e. when is it worst?
explain why?
worse in morning
lying down naturally increases ICP (no gravity)
a pt has raised ICP and is vomiting.
explain why?
↑ICP – vagus nerve pushed on and stimulated –>(vagus nerve innervates stomach), vomiting caused.
pt has raised ICP.
what is seen on ophthalmoscope?
papilloedema (big optic disk)
↑ICP – arteries give blood to eye, but high ICP presses on veins stopping venous drainage –> fluid leaks out, oedema.
what is the classic triad of high ICP called?
what is the triad?
Cushing’s Triad
HTN, bradycardia, bradypnoea
what is the classic triad of high ICP called?
explain each component of the triad.
↑ICP – brain not perfused & ischaemic, brain tells hypothalamus to drive SNS, arteries vasoconstrict, ↑HTN.
↑HTN – body now tries to compensate for this by reducing heart rate.
↑ICP – respiratory centre in medulla pushed on, bradypnoea.
where is the respiratory centre in the brain located?
medulla
what are the brain causes for a raised ICP?
- (i.e. what can increase brain volume)
- 4
tumour abscesses oedema blood in brain tissue: • haemorrhage • ruptured aneurysm