Increased Intracranial Pressure Flashcards
What is normal intracranial pressure?
5-15 mmHg
What is the Monro-Kellie doctrine?
Thevolume of the three components of the cranial vault - brain tissue, CSF, and blood - must remain constant in order to maintain stable ICP.
What are some common symptoms of increased ICP?
change in LoC (agitation, confusion), change in VS (Cushing’s Triad), ocular abnormalities - severe damage, headache, vomiting w/o nausea
What diagnostic test should not be performed in E-ICP?
Lumbar puncture - creates pressure gradient that can cause brain stem herniation.
How is E-ICP diagnosed?
CT / MRI / PET, EEG, cerebral angiography, ventriculostomy - pressure transducer “bolt”
What is important to remember about positioning patients with E-ICP?
Keep head of bed elevated
What is important to remember about positioning patients with a skull flap?
Do not roll them on to the side with the flap.
What does nitrazine paper test for?
Presence of CSF.
Why are hypertonics useful in E-ICP?
The pull fluid out of brain tissue.W
What is a coup-countercoup injury?
Brain “whiplash” injury to both ends of the axis of impact.
What is normal cerebral perfusion pressure?
60-100 mmHg
How do you calculate MAP?
diastolic + 1/3 pulse pressure.
ex: 120/80 => 120 + (40/3) = 93 mmHg
What is cushing’s triad?
Hypertension with widening pulse pressure (to maintain cerebral perfusion)
Bradycardia to compensate for hypertension
Irregular respiration due to pressure on the brain stem
What are the four stages of E-ICP?
- total compensation
- reduced compensation
- failure to compensate (without herniation)
- herniation & death
What are the three types of cerebral edema?
Vasogenic - most common, fluid moves from tissues to vasculature (M-KD: blood)
Cytotoxic - cell membrane dispruption moves fluid from vasulature into tissues (M-KD: tissue)
Interstitial - usually a result of hydrocephalus (ventricular enlargement from excess CSF produced or retained). (M-KD: CSF)
