Intracranial regulation Flashcards
What is a normal ICP?
10-15 mmHg
What is the normal CPP?
70-95 mmHg
How do you calculate CPP?
MAP - ICP = CPP
What happens when the CPP is too low?
The brain is not being perfused and the brain tissue will die
What is the normal MAP?
70-100 mmHg
How do you calculate MAP?
2 x DBP
+ SBP
divide by 3
What are some things that increase ICP?
Hypercarbia
ET or oral tracheal suctioning
coughing
extreme neck or hip flexion/extension
HOB < 30 degrees
increasing intra-abdominal pressure (tight clothes, vomiting, sneezing)
What are some things that decrease ICP?
HOB at least 30 degrees
maintain body midline
maintain patent airway
reduce stimuli
maintain c-spine until cleared
What is the earliest s/sx of increased ICP?
alterations in LOC & respirations
confusion
cheyne stokes
apnea
What are the other signs of increased ICP?
pupils uneven, blurry, double
weakness or paralysis on the opposite side (early)
posturing: decor or decere (late)
HA
N/V
fever
seizures
cushing’s triad (late)
What precautions are patients with increased ICP on?
NPO
seizure
fall
What can the nurse do to decrease the ICP?
ventriculostomy: cath in the brain to drain CSF and monitor ICP
neuro checks q15 min
give mannitol or hypertonic saline
vasopressors
manipulate CO2 (hyperventilate)
craniotomy
Prevent straining
decrease stimulation
What is the function of mannitol?
Osmotic diuretic
pulls fluid off the brain & into the vascular system
increases cerebral O2 delivery
What patients cannot receive mannitol?
renal disease patients
What should be monitored while giving mannitol?
glucose bc its a concentrated sugar
monitor serum osmolality levels
-should be 265-295
-neuro defects can be seen at 315
-high is concentrated and low is diluted
What is the function of hypertonic saline?
has the same action as mannitol but this is in a drip form
maintains the ICP level
What should you monitor while giving hypertonic saline?
BP
NA level (watch for fluid overload)
give slowly
What is the function of barbiturates (phenobarbital) for increased ICP?
to decrease brain metabolism
decreased ICP and cerebral edema
requires close monitoring
What should be given as a prophylaxis for seizures when a patient has increased ICP?
Phenytoin
Fosphenytoin
What should not be given when a patient has increased ICP with decreased LOC, and why?
Opioids
sedatives (promethazine)
because this will decrease their LOC (which is already low), and we will not be able to get an accurate neuro assessment
What are the priority interventions for increased ICP?
assess ABCs
O2
ventriculostomy (constant ICP monitoring)
neuro checks w/ GCS
do not remove the c-collar
Head CT w/o contrast to see bleeding
What is the major complication of increased ICP?
Brain Herniation
so much pressure that the brain is coming out of the bottom of the skull because there is nowhere to go
brain death will occur
prevent this by frequent neuro checks and craniotomy
