10.2 Raised ICP

Question 1

monroe-kellie doctrine

Answer 1

an increase in one of blood, css or brain must be compensated by a decreased volume of one of the others.

it’ll be css then venous blood, then arterial then. brain

Question 2

how does raised MAP affect CPP

Answer 2

increases, so vasoconstriction of cerebral blood vessels occurs to prevent too much blood to brain

Question 3

too much blood causes raised ICP. Give examples of causes for too much blood

Answer 3

within cerebral vessels
-rasied arterial pressure: malignant hypertension
-raised venous pressure: SVC obstruction

outside vessels
-haemorrhgae
haeorrhgaic stroke

Question 4

hydrocephalus clinical signs

Answer 4

bulging head (fontanelles and sutures not yet ossified)

sunsetting eyes (direct orbit compression, CN3 involevement)

Question 5

management of hydrocephalus

Answer 5

-tap fontanelle with needle if acute
-extrnal ventricular drain
-VP shunt long term

Question 6

when not to do LP and why?

Answer 6

intracranial pathology, can precipitate brain herniation

Question 7

scan for raised ICP

Answer 7

CT

Question 8

later signs of raised ICP (due to inadequate perfusion)

Answer 8

focal neurological signs

seizures

decreased GCS

increased BP

Question 9

subfalcine herniation

Answer 9

cingulate gyrus pushed under free edge of fall cerebra

Question 10

effects of uncal herniation

Answer 10

cn3 palsy
contralateral hemiparesis (compression of cerebral peduncle)

Question 11

why wouldn’t you use antiHTN for raised ICP?

Answer 11

can deprive brain areas which are just about OK, of enough blood

Question 12

management of raised ICP

Answer 12

-maintain oxygenation
-maintain MAP
-sedation, analgesia to decrease metabolic demand
-head up tilt 10-15 digress to help cerebral Venus drainage
-anti seizure meds
-PPIs to prevent stomach ulcers due to increased vagal activity