TBI/ICP Flashcards
3 intracranial components
- brain tissue
- blood
- CSF
6 factors that influence ICP
- arterial pressure
- venous pressure
- intraabdominal/intrathoracic pressure
- posture
- temperature
- blood gases (especially CO2)
ICP normal range
5-15 mmHg
ICP emergency level
20 mmHg
herniation
- brain tissue is forcibly shifted from a compartment of greater pressure to a compartment of less pressure
- forces cerebellum and brainstem down through foramen magnum causing respiratory distress/arrest
vasogenic cerebral edema
- most common type
- results from disruption of BBB
- fluid leaks from intravascular to extravascular space
- Sx range from headache to coma and death
cytotoxic cerebral edema
- results from disruption of cell membrane integrity
- develops from trauma or toxins
- fluid and protein shifts from extracellular space into cells causing swelling and loss of cellular function
interstitial cerebral edema
- usually caused by hydrocephalus (buildup of fluid in the brain)
- ventricular enlargement
- can be due to excess CSF production, obstruction of flow, or inability to reabsorb the CSF
manifestations of increased ICP
- decreased LOC
- Cushing triad
- ipsilateral pupil dilation
- sluggish/no response to light
- fixed, unilateral dilated pupil (emergency)
- hemiparesis/hemiplegia
- decorticate/decerebrate posturing
- headache
- projectile vomiting not preceded by nausea
Cushing triad
- systolic hypertension w/ widening pulse pressure
- bradycardia
- irregular respirations
medical emergency - sign of brainstem compression and impending death
complications of uncontrolled increased ICP
- inadequate cerebral perfusion
- cerebral herniation
tentorial (central) herniation
brain herniates downward through foramen magnum
uncal herniation
lateral, downward herniation
cingulate herniation
lateral displacement of brain tissue
diagnostics for increased ICP
- CT
- MRI
- EEG
- cerebral angiography
- CBC, coagulation, electrolytes, creatinine, ABGs, ammonia, drug/toxicology
- CSF analysis - protein, WBC, glucose
*lumbar puncture is contraindicated
ICP monitoring should be initiated in patients with GCS of ____ or less
8
ventriculostomy
- directly measures pressure within ventricles
- gold standard for monitoring ICP
- aseptic technique
Interventions for increased ICP
- HOB 30 degrees
- mannitol
- ventilation
- monitor ABGs
- surgery
drug therapy for increased ICP
(4 types)
- mannitol
- hypertonic saline
- corticosteroids
- barbiturates (if refractory to other tx)
GCS 15
fully alert
GCS 8
Coma
