Intracranial Regulation Flashcards
To function optimally, the brain needs adequate ________ (delivery of oxygen and nutrients), _____transmission (send excitatory or inhibitory impulses), ______ (because the brain does not store it),
perfusion
neurotransmission
glucose
The cranial vault is the boney protective covering of the 3 following things:
a. Brain ______ (80%)
b. _____ (10%)
c. ___________ fluid (10%)
tissue
blood
Cerebrospinal fluid
a. Brain tissue (80%)
b. Blood (10%)
c. Cerebrospinal fluid (10%)
If one of the three things above expands, the other two must decrease to maintain normal intracranial pressure
_ _ _ will shift first, then blood, then the brain.
If the brain has to shift because pressure is too high then it can has __________.
CSF
herniation
Normal intracranial pressure is 5 to __ mmHg.
Pressure may be increased by tumors, _____, excess CSF, __________.
15
edema
hemorrhage
_____ trauma results from injury to the brain.
a. ______ trauma occurs when there is edema but no opening
i. __________: diffuse brain injury; head is shaken
ii. _________: focal injury; like a bruise on the brain so there is blood leaking from the injured blood vessels
b. ____ head trauma occurs when a break in the dura results in exposure of cranial contents
Brain
Closed
Concussion
Contusion
Open
Increased intracranial pressure may be due to increased _____:
a. Hemorrhages or hematomas
b. Decreased oxygen > cerebral vasodilation > increased blood flow
c. Increased carbon dioxide > cerebral vasodilation > increased blood flow
d. Hypertension may decrease cerebral perfusion pressure (BP so high that CPP is increased so vessels dilate and leak, which also increases intracranial pressure)
e. Hypotension < 100 mmHg may lead to decreased cerebral perfusion pressure
i. If blood pressure is too low the body will try to vasodilate to get more blood into the brain because the flow has decreased, however, when more blood comes, that means volume increases so intracranial pressure increases
f. Decreased jugular venous drainage
blood
Intracranial pressure may be increased due to increased _ _ _
a. _____cephalus
i. Characterized by____________ of CSF flow, decreased reabsorption of CSF, and/or increased production of CSF, which causes the ventricles to _____ and intracranial pressure to increase
CSF
Hydrocephalus
obstruction
swell
is inflammation of the optic disc that is caused by obstruction of venous return.
INCREASED intracranial pressure.
Papilledema
_ _ _ (70 to 110) = _ _ _ (70 to 110) – _ _ _ (5 to 10)
Cerebral Perfusion Pressure - the amount of pressure needed to maintain blood flow
CPP
Mean Arterial Pressure - diving force that pushes blood into the brain
MAP
Intracranial Pressure - force that keeps blood out
ICP
Stages of Intracranial Pressure Changes: (4 Stages)
Stage 1
i. In compensation: awake and alert, pupils _____ and reactive, NORMAL vitals
ii. ______________ occurs
1. Intrinsic ability of tissues to regulate own blood flow to meet metabolic needs by altering the size of vessels
equal
Autoregulation
Stages of Intracranial Pressure Changes: (4 Stages)
Stage 2
i. Still in compensation and autoregulation but beginning to see episodes of __________, restlessness, and lethargy (changes in LOC) as intracranial pressure increases
ii. Normal vital signs and equal and reactive pupils
confusion
Stages of Intracranial Pressure Changes: (4 Stages)
Stage 3 i. Compensation and autoregulation \_\_\_\_ > intracranial pressure approaches arterial pressure > compression of cerebral vessels > decreased _ _ _ > brain hypoxia and hypercapnia > vasodilation > ischemia and acidosis
ii. Autoregulation has been lost
iii. More LOC changes
iv. _____, reactive pupils
v. Slower breathing
vi. Pulse pressure ______
vii. Pulse begins to drop (bradycardia)
Fail
CPP - Cerebral Perfusion Pressure
Small
Widens
Stages of Intracranial Pressure Changes: (4 Stages)
Stage 4
i. Severely increased ICP > herniation from high to low pressure
ii. ICP and mean systolic arterial pressure equal so CPP is 0 (__ blood flow)
iii. Lethargy into ____
iv. _________ dilation and fixation to bilateral dilation and fixation
v. Cushing’s _____ (increased systolic BP, widened pulse pressure, bradycardia)
No blood flow
Coma
Ipsilateral Dilation (o O)
Triad
______ shock is a loss of all neuronal messages below the area of the lesion > flaccidity below the level of the injury. Reflexes are lost for 7-__ days.
Spinal
20 days
_________ dysreflexia causes excessively ____ blood pressures that may cause a cerebral __________ (a stroke).
Autonomic dysreflexia
HIGH
hemorrhage
