Exam 2 review sheet Flashcards
Brain uses what for metabolism?
glucose and oxygen
Autoregulation is the brains ability to? When does it shut down
- maintain constant cerebral blood flow
- less than 60, greater than 160 systolic, or cerebral perfusion suboptimal
Arterial is the ? system in the brain
- High Pressure System
- Thinner & more fragile
- Carotid & Vertebral arteries supply blood to the brain
- Circle of Willis: where blood flows up and is able to flow over to the oppposite side
Venous is the ? Pressure System
- Low pressure system
- Lack valves
Compress easily with Increase Pressure
*
Cerebral Perfusion Pressure
- CPP= MAP –ICP
- Normally greater than 50
- Less than 50 indicates loss of autoregulation
Monro Kellie Hypothesis
- Changes in the brain volume result in
- Increased ICP
- (or) decrease in one of the other volumes
Compliance is the attempt to ?
- Compliance is the attempt to maintain the ICP between 5-15 mm/hg
- CSF displacement
- CSF reabsorption
- Venous compression and blood shuntin
- ensure cererbral blood flow
Decrease in CBF leads to?
- Ischemia
- Build-up Lactate (does not cross blood brain Barrier)
- Ultimately cerebral acidosis
Hyperemia
- Is increased blood flow to brain. Causes arterial congestion
- Luxury Perfusion
- Progressive vasodilation
- Increased CBF
- Loss of Autoregulation: Increased ICP
conditions that increase cerebral blood flow
- Hypertension
- Fever
- Pain
- Hypercapnia
- Ischemia
- Cerebral vasodilation
conditions that decrease cerebral blood flow
- Hypotension
- Sedation
- Paralysis
- Hypocapnia
- Cerebral edema
- Decrease CO
- Cerebral vasoconstriction
Confusion
Disorientation differences?
disorientations: agitation and anxiety plus the confusion
obtunded
responses are slower
stupor
only respond with painful stimuli
coma
don’t respond to painful stimuli
Vowel- TIPPS
Common Reasons for altered LOC
Vowel-Tipps
- Alcohol
- Epilepsy
- Insulin
- Opiates/drugs
- Uremia
- Trauma
- Temperature
- Infection
- Psychogenic
- Poisin
- Shock-Stroke
Glascow coma scale
- Looks at eye opening, verbal response, motor response.
- Higher the score the higher the function
- Score less than 9=concern
decerebate
arms flexed down and out, and you’re dying
decorticate
pulled in towards your core, you can fix it
What is a positive Dolls Eyes?
turn the patient and the eyes stay fixed straight. Head goes sideways and eyes go sideways too
Caloric Ice Test negative and positive findings?
- insert 20 ml of cold water into the ear. You expect to see the eyes start moving, and then they fix over to the side you put the ice water in. This would be a normal response and a negative eyes test
- abnormal response is the eyes staying fixed
Cranial Nerve Assessment
- Corneal: stick something on cornea, they blink (normal)
- Gag
- Swallow
- Cough
S/S of Increased ICP infants, children
- Infants
- Bulging fontanel
- Separated cranial sutures
- Cracked-pot sign: bang on head, sounds like a hollow pot (extra fluid)
- Setting-sun sign: eyes are low set and whites are showing above it
- Positive transillumination
- Children: c/o headaches, projectile vomiting, and new seizure onset activity
neurologically small pupils
damage to pons
neurologically big pupils
damage to brain stem
fixed pupil that is dilated =
impending herniation
Early Signs of ↑ ICP
- Slight LOC changes ***MOST IMPORTANT****
- Pupils sluggish / Impaired eye movement
- Limb strength changes
- Headache
ICP Peaks?
48 – 72 hours after injury
Cushing’s Triad: Signs of ↑ ICP
Blood Pressure
- Systolic BP Increases - Diastolic BP Decreases - Pulse Decreases
Widening Puse Presure
Bradycardia
Might also see cheyne-stokes breathing and elevated temperature
Brain Herniation occurs when
a part of the brain pushes downward inside the skull through the opening that leads into the neck
(Foramen Magnum)
How To Minimize Cerebral Edema?
Maintain
Cerebral perfusion pressure
CPP of 50 – 70 mm Hg
Prevents Hypoxia (Hypercarbia)
early herniation
- potentially reversible
- level of conciousness may not be impaired initially
- alert to stuperous, pupils sluggish, cheyne-stokes respiration, slight increase in pulse pressure
Herniation to the mid-brain/upper pons
Deep Coma, Dolls eyes, pupils fixed, posturing, hyperventilation, wide pulse pressure
herniation to medulla
- late phase of UNCAL herniation
- irreversible (terminal)
- Deep Coma
- no pupillary response
- cluster or apneic
- pulse pressure starts to narrow again
EEG
Used to:
- Electrical Activity
- Identify seizure activity
- Determine Brain Death
Encephalography
Used to
- Identify shifts from midline
- May show ventricular dilation
CT scan vs MRI
CT: Show Horizontal and Vertical Cross Sections
MRI: Show tissue discrimination
ICP monitoring indications
- Severe Head Injury
- GCS 3-8 (less than 9)
- Abnormal Imaging
- SBP less than 90 mm/hg
- Subarachnoid hemorrhage
- Hydrocephalus
- Brain tumors
- Stroke
- meningitis
contraindications for ICP
- Central nervous system infection
- Coagulation defects
- Anticoagulant therapy
- Scalp infection
- Severe midline shift resulting in ventricular displacement
- Cerebral edema resulting in ventricular collapse
normal icp for adults
15
maintaning ICP
- Q 1hour Neuro Checks
- Monitor MAP, ICP, CPP (MAP-ICP)
- Monitor ICP wave Forms
- Strict Asepsis
- Assess ICP site
- Watch for CSF leaks (ear, see halo with the fluid)
- Watch for Blood in the ICP monitoring system (should never see blood in there)
Never use a ? for ICP monitoring
- never use a flush device. Use only sterile 0.9% NaCl to fill the pressure tubing.
- Never use a heparinized solution.
Patients are maintained in a ? head up and neutral position when necessary to minimize the ICP.
30-45 degree
Avoid ? of the neck and positioning the patient in a Trendelenberg position, all of which may increase ICP.
flexion and hyperextension of the neck
simultaneous drainage and pressure monitoring is ?
Simultaneous drainage and pressure monitoring is not recommended. To ensure precise pressure measurements, perform only pressure monitoring while keeping the stopcock closed to the drainage system.
Intraventricular monitoring advantages and disadvantages
*gold standard*
Advantages
- Allows for CSF drainage
- Provides direct measurement of CSF pressure
Disadvantages
- Most Invasive
- High risk for infection/ hemorrhage/ infection
- Contraindicated with coagulopathies
subarachnoid advantages/disadvantages
Advantages
- Less invasive
- Easy to place
- Low risk of infection
- Able to sample CSF
- Can be used if ventricles are not able to be cannulated
Disadvantages
- Unable to drain CSF
- Decreased accuracy with time
- Needs frequent recalibration
- Easy to be obstructed with bone/tissue
Intraparenchymal advantages/disadvantages
advantages
- Easy placement
- Low risk of infection
- Highly accurate
disadvantages
- Unable to drain CSF
- Needs a separate monitoring system
- Catheters kink easy
- Risk of hemorrhage/ infection
- Can not be re-zeroed
Epidural Probe advantages/disadvantages
advantages
- Easy placement
- Low risk of infectin
disadvantages
- Unable to drain CSF
- Can not be re-zeroed
- Accuracy questionable
ICP monitor level
- head 30 degrees
- ear in line with transducer
- leveler is at 90 degrees (upright)
osmotic diuretic for ICP
Mannitol
- Pulls fluid into the cerebral vascular space
- Reduces cerebral blood viscosity
- Increases cerebral blood flow
- Increased cerebral oxygen delivery
- Dosage: 1.0 gm/kg
- Nurse considerations: Watch serum osmolality
Targeted Temperature Management in ICP
- Reduces ICP
- Decrease levels of excitatory neurotransmitters
- Cerebral edema
- Free radicals
- Cerebral metabolic rate
- 33 degrees celcius
Nursing management of targeted temperature management
Monitor for S/S of:
- Shivering
- Arrhythmias
- Coagulopathies
- Hypothermia-induced diuresis
- Electrolyte imbalance
- Hiccoughs
- Rewarming slowly
Seizure Precautions
- Seizures are very common with increased ICP
Phenytoin may be initiated with
- GCS less than 10
- Cortical Contusions
- Depressed skull fractures
- Subdural, epidural and intracerebral hematomas
- Penetrating head injuries
- A seizure within the first 24 hours post injury
Nursing considerations: Safety
- Oral airway
- Side rails padded
- Suction and oxygen set-up
- Patient/ family teaching
- Administration and monitoring of pharmacological interventions
ALL Cranial Injury things to do?
ATLS (asvance trauma life support)evaluation & intervention
(ABCs / Foley / NG / oxygen / Maintain traction)
Constant Monitoring
*Diagnosis:
- CT scan (FAST!)
- MRI
- PET Scan (brain function assessment)
*Medical interventions depend on severity:
- Endotracheal intubation / hyperventilation
- Sedation
- Diuresis
- Rapid surgical evacuation
Nursing Interventions for Acute Head Injury
- Continuous monitoring of Vitals, PERRL and Glasgow Coma Score
- Report client condition changes ASAP
- Maintain airway patency- positioning, suctioning (if necessary)
- Minimize cerebral edema
- Maximize cerebral perfusion
- Implement seizure precautions / Siderails
- Provide emotional support
- Address all self-care deficits
Collaborative care for seizures
Anticonvulsants
- Phenytoin (Dilantin)
- 10-20 mg/kg loading dose
- Mix with NS not dextrose
- 25-50 mg/min IVP
- Monitor MP and Heart Rate x 30 min: May use Fosphenytoin children (SIVP or IM)*
-Benzodiazepine: Given emergent with Dilantin
Keatogenic Diet: High fat, low carb, low protein
Vagus Nerve Stimullator: implanatble device that stimulates the vagus nerve. Done after trying 3 or more meds
nursing care for seizure pts
- Make certain that the patient has the following equipment: Nasal cannula and tubing, Oxygen flow meter; , Suction gauge, Suction canister, Suction tubing to connect to canister
- Assign patient to room in close proximity to the nurses station
- Maintain continuous observation via video monitor or sitter
- Pad side rails of bed
- Keep bed in low position with all side rails up at all times
- Keep unnecessary equipment out of patients room
- Instruct patient not to get out of bed without assistance
- Assure that call bell is always within patients reach. Make sure that the family knows where it is and how to use it
- Avoid use of restraints
- Check vital signs every fifteen minutes and maintain airway patency during the post ichtal phase (period of time immediately following the seizure, during which the patient remains comatose or stuperous).
Types of Head Injury
- Linear (very small line) or depressed skull fracture
- Simple, compound, or comminuted
- Closed or open
- Direct and Indirect
- Coup (head goes forward quickly and the injury goes to the back of the brain) and Countercoup (head goes back quickly and injures the front of the brain)
Basal Skull fractures
- CSF leakage through nose or ear
- high risk for infection
- battle signs (bruising behind ear)
- raccoon sign (bruising around the eyes)
- possible injury to internal carotid artery
- permanent CSF leakage
Minor injury vs. Severe
Minor
- May loose conciousness
- transient period of confusion
- somnolence
- listlessness
- irritability
- pallor vomiting
Severe
- Increased ICP
- Bulging fontanel (infants)
- reinal hemorrhages
- extraocular palsises (CN111)
- hemiparesis
- quadraplegia
- increase temperature
- change in gait
- papilledema
Temporary loss of consciousness, GCS 13-15
Mild Head Injury
obtunded for several hours, GCS 10-12
moderate head injury
in a coma, GCS less than or equal to 8
severe head injury
Concussion grading scale: Grade 1
- Transient confusion
- no loss of consciousness
- symptoms resolve in less than 15 minutes
Grade 2 concussion grading scale
- transient confusion
- no loss of consciousness
- symptoms last more than 15 minutes
concussion grading scale: Grade 3
Any loss of consciousness, brief or prolonged
contusion vs. laceration
contusion: bruising of brain tissue withing a focal area that maintains the integrity of the pia mater and arachnoid layers
Laceration: involve actual tearing of the brain tissue. Intracerebral hemorrhage is generally associated with cerbral laceration
Epidural hematoma
results from bleeding between the dura and the inner surgace of the skull. It is a neurologic emergency and of venous or arterial origin
Subdural hematoma
Occurs from bleeding between the dura matter and arachnoid layer of the menigeal covering of th ebrain
diffuse axonal injury
widespread axonal injury occuring after a mild, moderate, or severe tbi
IVH causes
- Infants born before 30 weeks of pregnancy are at highest risk for such bleeding (smaller and younger, higher the risk bc blood vessels are premature and fragile)
- IVH is more common in premature babies who have had: respiratory distress syndrome, high BP, can occur in healthy premature babies born without injury
- Rarely present at birth
- Develops in first several days of life, and rare after one month of age
- Falls into 4 grades, the higher the grade the more severe the bleeding
- Presses on or leaks into the brainm, blood clots form around that, leads to increased fluid volume creating hydrocephalus
grades of IVH
- Grade 1 &2 involve small amounts of bleeding and do not usually cause long term problems
- Grade 3 & 4 involve more severe bleeding
IVH symptoms
- There may be no symptoms
- Breathing pauses
- Changes in BP and heart rate
- Decreased muscle tone
- Decreased reflexes
- Excessive sleep
- Lethargy
- Weak Suck
3 stages of clinical presentation of IVH
Catastrphic
Acute IVH with bulgin fontanel, spil sutures, change in level of consciousness, pupillary and cranial nerve abnormalities, decerebrate posturing, and often with rapid decrease in blood pressure andor hematocrit.
Saltatory
Gradual deterioration in neurological status, may be subtle abnormalities in level of consciousness, movement, tone, respiration and eye/position movement
Asymptomatic
25-50%, discovered on ultrasound. Fall in hematocrit or failure of hematocrit to rise wiht tranfusion should cause concern
Grade 1 IVH
bleeding condined to periventricular area (germinal matrix)
Grade 2 IVH
Intraventricular bleeding less than 50%
Grade 3 IVH
intraventricular bleeding greater than 50%
Grade 4 IVH
Intra-Parenchymal echodensity (IPE) reperesents periventricular hemorrhagic infarction
diagnostic testing for meningitis
- bacterial culture and gram staining of csf and blood are key diagnostic tests
- the presence of polysaccharide antigen in csf futher supports the diagnosis of bacterial meningitis
signs of meningitis in child vs. adult
adult: vomiting, headachem drowsiness, seizures, high temp, stiff neck, joint pain, dislike of light
child: high pitched cry, dislike of being held, fearful, arching back, blank staring expression, pale blotchy skin color, refusing feeds or vomiting, fever, may have cold hands and feet, difficult to wake up, very lethargic
nursing managmenet of meningitis, and S/s
- frequent/continual assessment including vs and LOC
- protect patient form injury related to seizure activity or altered LOC
- monitor daily weight, serum electrolutes, urine volume, specific gracity, and osmolality
- prevent complications associated with immobility
- infection control precautions
- supportive care
- measures to facilitate coping of patient and family
s/s meningitis
- Look for kurnig sign: hip and knee flexed 90 degrees, and when you try to extend it it’s painful
- brudzinski sign: pt is laying extended, bring up their neck, and their knees will flex up
- petichiae that if you blanch it they won’t go away
Uniform determination of death act
- irreversible cessation of circulatory and respiratory function
- irreversible cessation of all functions of the entire brain, including the brain stem, is dead.
- A determination of death must be made in accordance with accepted medical standards.
conditions must be met to determine brain death
- apneaic testing
- testing with cranial nervees
- diagnostics with brain imaging and brain blood flow: If the first 2 are inconclusive, then this one is done or under the age of 1
- Brain death is a clinical diagnosis. It can be made without confirmatory testing if you are able to establish the etiology, eliminate reversible causes of coma, complete fully the neurologic examination and apnea testing.
- The diagnosis requires demonstration of the absence of both cortical and brain stem activity, and demonstration of the irreversibility of this state.
What are the cranial nerve responses we see in brain death?
- No pupillary response to light. Pupils midline and dilated 4-6mm.
- No oculocephalic reflex (Doll’s eyes) – contraindicated in C- spine injury.
- No oculovestibular reflex (tonic deviation of eyes toward cold stimulus) – contraindicated in ear trauma.
- Absence of corneal reflexes
- Absence of gag reflex and cough to tracheal suction.
Apnea Testing
- Once coma and absence of brain stem reflexes have been confirmed –>Apnea testing.
- Verifies loss of most rostral brain stem function
- Confirmed by: PaCO2 > 60mmHg, or PaCO2 > 20mmHg over baseline value.
- Testing can cause hypotension, severe cardiac arrhythmias and elevated ICP.
- Therefore, apnea testing is performed last in the clinical assessment of brain death.
Following conditions must be met before apnea test can be performed:
- Core temp > 35.0 C
- Systolic blood pressure > 90mmHg.
- Euvolemia
- Corrected diabetes insipitus
- Normal PaCO2 ( PaCO2 35 - 45 mmHg).
- Preoxygenation (PaO2 > 200mmHg).
Criteria for Brain Death in Children
- Neonate less than 7 days —> Brain death testing is not valid.
- 7 days – 2 months: Two clinical exams and two EEG 48 hrs apart.
- 2 months – 1 year: Two clinical exams and two EEG 24 hrs apart, or two clinical exams, EEG and blood flow study.
- Age > 1 year to 18 years: Two clinical exams 12 hrs apart, confirmatory study (Optional)
*
Loss of brain stem function results in systemic physiologic instability including?
- Loss of vasomotor control leads to a hyperdynamic state.
- Cardiac arrhythmias
- Loss of respiratory function
- Loss of temperature regulation –> Hypothermia
- Hormonal imbalance –> DI, hypothyroidism
Intensive care management of cardiovascular sytem rule of 100’s
- Maintain SBP and PaO2> 100mmHG
- maintain HR and Urine output < 100 BPM
Brain death results in a massive release of?
Massive release of catecholamines, aka “autonomic storm”
Hypotension management in brain death
- Fluid Bolus – NS or LR ((Followed by MIVF (maitenance IV fluids) NS or .45 NS))
- Consider colloids
- Dopamine: increase contractility of the heart and promote vasoconstriction
- Neosynephrine: increase contractility of the heart and promote vasoconstriction
- Vasopressin: helps with urine output
- Thyroxine (T4 protocol)