Increased Intracranial Pressure and Traumatic Brain Injury
What nutritional therapy considerations would a patient with IICP need?
Being in a hypermetabolic and hypercatabolic state increases the need for glucose so you have to ensure they are getting nutrition, either through enteral or parenteral routes. Starting feeds within 3 days of injury promotes better outcomes. Keep patient normovolemic and use IV 0.9% NaCl
How does controlled hyperventilation help with IICP? What are the risks?
It blows off CO2 which causes vasoconstriction of arterioles which decreases cerebral blood volume (thus decreasing ICP), recent research says it may or may not be helpful, have to be careful because severe hypocapnia causes ischemia
Why would you avoid valsalva maneuver and straining in a patient with IICP?
It increases intraabdominal and intrathoracic pressure which further increase ICP
Cushing's triad (what is it a sign of, what are the manifestations)
Late sign of increased ICP, made up of increased systolic BP (widened pulse pressure), bradycardia with bounding pulse, and irregular respirations
What are the types of skull fractures?
Linear nondisplaced, depressed, compound, penetrating objects, basilar
What is diabetes insipidus?
Loss of large volumes of dilute urine in the presence of normal or high plasma osmolality
How and why would you maintain a controlled metabolic rate with an IICP patient?
Maintain a normal temperature, prevent seizures, control blood sugar, control pain and anxiety - neuromuscular blockers: vecuronium bromide (Norcuron) - sedatives: Propofol
What drug would you use for getting rid of edema/fluid and what are the considerations for it?
Mannitol- osmotic diuretic - need to give through a filtered needle - rapid onset of 15 minutes - main side effect is dehydration - assess urine output, I&O, and serum osmolarity
What are the components of a neurologic examination?
Mental status: oriented x3? Level of consciousness PERLA Cranial nerve function Cerebellar function (romberg) Reflexes (gag, cough, deep, babinski) Sensory and motor function bilaterally
Care for a basilar skull fracture
Minimize coughing, sneezing, valsalva maneuver, no nasal suctioning or nasogastric tube, do not pack ears or nose if there is a CSF leak (use a sterile nonocclusive gauze), assess for infection
Why do we want to prevent repeated concussions?
Multiple concussions can cause permanent injury or lead to chronic traumatic encephalopathy
Care for a depressed skull fracture
Need protective device/helmet, position them so they aren't leaning on the depressed area, debride and irrigate wound, if it is more than a 5 mm depression they may undergo acrylic cranioplasty
What are some indicators of brain death?
Negative oculocephalic response, negative oculovestibular response, no corneal reflex when stimulated, can't breathe on own off ventilator
What diagnostic tools would you use for IICP/TBI?
Neurologic examination, monitoring devices for ICP, vital signs assessment, CT scan, MRI, transcranial doppler, cerebral arteriogram
What are the rating categories for best motor response (GCS)
No response (1), extension/decerebrate (2), abnormal flexion/decorticate (3), withdrawal flexion (4), localizes pain (5), obeys commands (6)
What are the rating categories for best verbal response (GCS)
No response (1), incomprehensible sounds (2), inappropriate words (3), disoriented and converses (4), oriented and converses (5)
What are the rating categories for eyes (GCS)
No response (1), open to pain (2), open to verbal command (3), open spontaneously (4)
Basilar skull fracture
Occurs at base of skull, top of neck, near spine, manifested by racoon's eyes, battle's sign, otorrhea or rhinorrhea, halo or ring sign
What are the cranial nerves (in order)
Olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, accessory, hypoglossal
How would you assess each cranial nerve?
Olfactory: have them identify smells Optic: snellen chart or read something Oculomotor: cardinal fields of vision Trochlear: cardinal fields of vision Trigeminal: have them clench jaws Abducens: cardinal fields of vision Facial: have them smile Vestibulocochlear: check hearing and balance Glossopharyngeal: assess swallowing and gag reflex Vagus: assess heart rate Accessory: have them push shoulders against resistance Hypoglossal: have them stick out tongue
Craniectomy
Opening up the skull and removing the bone flap - resolves IICP resulting from midline shifts - brain needs room to swell for weeks to months
Craniotomy
Opening up the skull but putting the bone back
What is your oxygenation goal for someone with IICP?
PbO2 20-40 mmHg
Barbiturate coma
Pentobarbital IV drip or IVP depresses the CNS, CV, and respiratory systems - alters assessment - need mechanical ventilation and total physical care - may assess effectiveness with EEG or BIS - drug holidays and inform family of effects
How would you position someone with IICP?
Position with head of bed elevated to promote jugular venous drainage, head in alignment with body when positioning
Why wouldn't you do a lumbar puncture for IICP patients?
Pulling off fluid with suction can cause brain herniation
What would you be looking for/to prevent with a vital signs assessment?
BP needs to be maintained to perfuse the brain so you need to watch for and avoid hypotension, treat bradycardia less than 40-50, watch for cushing's triad
What is the normal serum osmolarity?
260-300 mmHg
Normal intracranial pressure
5-15 mmHg
What are the normal and bad ranges for CPP?
60-100 mmHg is normal, less than 50 is ischemia/death
Why are neuro examinations important diagnostic/monitoring tools for IICP/TBI patients?
Allows you to closely monitor for changes that could indicate worsening injury to brain/increasing pressure
What are the early, moderate, and late manifestations of IICP?
Early: changes in level of consciousness and confusion Moderate: LOC changes, motor changes, pupil changes, disconjugate eye movement, vomiting, headache, papilledema Late signs: fixed pupils, extreme motor changes or no response, loss of reflexes, cushing's triad
What is the major diagnostic test for IICP?
CAT scan
How to calculate CPP
CPP= MAP-ICP
Epidural hematoma characteristics
Caused by interruption of the middle meningeal artery (on the side of head), fast bleed above the dura -classic s/s: loss of consciousness, awake, then coma
Subdural hematoma characteristics
Caused by tearing of bridging veins between brain and dura, blood pools between the dura and the arachnoid membrane - because it is a venous bleed the s/s do not happen as fast - acute signs happen in 24-48 hours
Why would you use therapeutic hypothermia?
Cooling of the body less than 36 degrees celsius protects the brain by inhibiting depolarization, stabilizing the blood brain barrier, decreasing cerebral metabolic rate, which causes a decrease in CO2 and lactate - initiate early with a duration of 24 hours
Care for a linear nondisplaced skull fracture
Debride and irrigate wound if needed, assess for infection
What would decorticate or decerebrate movements look like in a patient?
Decorticate is when they pull their arms towards their core, decerebrate is when they extend their feet out
What are the side effects of therapeutic hypothermia?
Decreased cerebral perfusion, MAP, HR, hypokalemia, atelectasis, pneumonia, ARDS, rebound hyperemia, and cerebral edema during rewarming
What are the complications of IICP and TBI?
Diabetes insipidus and brain herniation
Causes of IICP
cerebral edema, concussion, contusion, hematoma, hydrocephalus, tumor
Why does Diabetes Insipidus happen with IICP?
Traumatic brain injury causes dysfunction of hypothalamic neurons secreting antidiuretic hormone
How would you care for a patient with IICP?
Treat underlying cause, positioning, intubation, mechanical ventilation, oxygenation and CO2 levels, avoid isometric exercise, bearing down, and sneezing, IV therapy, nutritional therapy, controlled hyperventilation, controlled metabolic rate, therapeutic hypothermia, barbiturate coma, continuous EEG monitoring
What types of monitoring devices are there for ICP?
Ventricular catheter (also for draining), ventriculostomy, LICOX catheter
Why does brain herniation happen with IICP?
Ventricular shift caused by increased pressure causes the brain to herniate because it doesn't have anywhere to go. Often caused by subdural hematomas
Intracerebral hematoma characteristics
also called a cerebral hemorrhage or hemorrhagic stroke, greater than 5 ml of blood -s/s depend on location, size, and rate of blood accumulation
Concussion symptoms
headache, N/V, incoordination, dizziness, visual problems, fatigue, difficulty thinking or concentrating, feeling slowed down, more emotional than usual
How do you treat diabetes insipidus in an IICP patient?
need to correct the underlying cause, then fluid replacement with IV hypotonic solutions, IV vasopressin
Glasgow coma scale
score is from 3-15, you want a higher number b/c anything less than 8 is a major brain injury, categories are eyes, best motor response, best verbal response