Neurological Illness Flashcards
What are the three components and the significance of the monro-kellie doctrine of fixed intracranial volume?
Parenchyma
CSF
blood
These things help self-regulate the intracranial volume/pressure, if one increases, one of the others must decrease.
What happens when the compensatory mechanisms for increase ICP fail?
Even the smallest increase in volume significantly effects ICP.
what is a very important thing that is effected by ICP?
cerebral blood flow
What is the normal ICP range?
0-15 mmHg
Does the brain autoregulate its pressures based on what the MAP of the body is to maintain a constant blood flow in response to continuosly changing blood pressures?
YES
How do you measure cerebral bloof flow?
CPP (cerebral perfusion pressure)
What needs to be present for autoregulation to be effective?
CPP >60
MAP <160
systolic bp of 60-140 mmhg
ICP less than 30
what are some things that can vasodilate the brain? vasoconstrict?
acidosis, hypercapnia, hypoxia
alkalosis, decreased PaCO2
What are some things that can increase BP in brain if autoregulation is absent?
coughing, suctioning, restlessness, ect..
How do you measure CPP?
CPP = MAP - ICP
What is the normal range for CPP?
60-100 mmHg
What are some causes of cerebral edema?
brain trauma
CNS infections
tumors
strokes
What are some signs of cerebral edema?
GCS <8
abnormal CT
signs of increased ICP - cushings triad
What are the three signs of cushings triad?
Increased pulse pressure (HTN)
decreased pulse
change in respiratory (bradypnea) pattern with pupillary changes
LATE SIGN OF INCREASED ICP
What are some other signs of increased ICP?
decreased LOC
diminished reflexes
papilledema (usually effects eyes bilaterally)
decorticate and decerebrate posturing
unequal pupils
projectile vomiting
altered breathing
HA
what is the primary goal of treating cerebral edema?
keep plasma osmolarity up to 320 mOsm/L
How do you monitor ICP? are there advantages? disadvantages?
intraventricular monitoring is the most common - can allow for CSF drainage.
allows drainage of CSF
difficult to insert, high rates of infection
What are some nursing management techniques for increased ICP treatment?
Position - HOB up 30-45 to decrease ICP 15-30 degrees, straight head, no trendelenburg. However - position the patient to help decrease ICP - whatever works!
Nursing Activities - limit suctionning, avoid valsalva, no PEEP, sedation
Hyperventilation - permissive hypocapnia, keep paCO2 35
Temp - vasodilation - hyperthermia, vasoconstrction - hypothermia
Blood pressure -maybe all it takes is sedation - if not, antihypertensives are used to keep CPP 60 - 100
Seizures -increased metabolic demand, causes ischemia
All interventions are directed toward decreasing volume of one of the 3 components
Lidocaine - through ET decreases ICP with suctionning
Table 34-5 page 791
Bowel – stool softeners, enemes, prevent constipation and valsalva!
Environment – limit stimuli, monitor conversations, gentle touch, dimming lights, back/hand rubs
What are some medical management therapies for increased ICP?
Neuromuscular Blockade – monitoring
Barbiturate Coma – suppress seizures
Blood Pressure Management - monitor the MAP!
Avoid hyper and hypotension
Seizure prophylaxis – drug of choice for acute seizures
Normothermia – decrease metabolic demand
Craniectomy
What are some warning signs of an aneurysm?
warning signs : headaches, lethargy, neckpain, optic, oculomotor cranial nerve dysfunctions
What are some aneurysm precautions?
Anuerysm precuations - quiet environment, prevention of valsvalva, stool softeners, limit visitors, low lighting,, sedation
What might a ruptured aneurysm look like?
once ruptured - will complains of worse headache in life, may have decreased LOC< visual disturbances, hemiparesis, vomiting, signs of ICP
How can you surgically treat an aneurysm?
Clipping - within 48 hours, across neck of aneurysm - preferred
craniotomy is performed
Coiling - blocks aneurysm from circulation
AVM - remove AVM very high risk!
What are some signs and symptoms of cerebral vasospams? What is triple H therapy? What medication can help decrease vasospasms completely?
Signs and symptoms - new focal deficit, hemiparesis, visual disturbances, decreasing LOC
Vasospasm – 4-14 days after rupture, peak at 7-10 days
3 days to 2 week after SAH, can last up to 3-4 weeks!
Hypertensions - vasopressors - get SBP between 150-160 - decreases spams
Hypervolemia - colloid and crystalloid solutions, volume expanders - watch for heart fialure!!!
Hemodilution - decrease viscocity and increase oxygen trasnport
nimodipine - calcium channel blocker can help prevent vasospasms
what is the window to administer TPA for a stroke? other inclusion criteria?
4.5 hours
older than 38
diagnosis of ischemic stroke with measurable deficit on NIHSS scale
CT: no high density lesion, no significant mass effect or midline shift, no parenchymal hypodensity, no effacement of cerebral sulci in more than 33% of MCA territory
What does hyperglycemia do in regards to stroke?
Increases infarction size
What are the different types of ischemic stroke?
embolic
thrombolic
Where can bleeds happen to cause hemorrhagic stroke?
subarachnoid
intracerebral
