Intracranial Problems Flashcards
What are the 3 components that make up intracranial pressure?
What is the Monro-Kellie doctrine?
Brain tissue
Blood
CSF
These 3 components must stay in balance within a closed skull.
If one of these rise the other 2 compensate to maintain a normal volume within space.
What is a normal ICP?
What is considered too high?
Normal is 5–15 mm Hg
High is >20 mm Hg
Why is it vital to maintain a CBF (cerebral blood flow) WNL?
How much MAP is necessary to maintain normal CBF?
This means it is critical to maintain MAP when there is an ICP!!
Brain requires constant supply of O2 and glucose and uses a lot of it.
Need MAP of at least 70 mmHg and no more than 150
What is cerebral perfusion pressure? (CPP)
How is it figured?
Normal?
Abnormal?
Pressure needed to have adequate cerebral blood flow. (CBF)
It is measured by MAP-ICF=CBF.
Normal is 60–100 mmHg
<50 is ischemia
<30 is death is near
Why is 100% oxygenation critical in increased ICP?
Prevents buildup of lactic acid in brain.
Lactic acid and hypercapnia lead to vasodilation in brain vessels and increased pressure.
What is herniation?
Brain tissue is forcibly shifted from the pressure, usually pushed through foramen magnum
Prevent this at all cost because brainstem damaged, respiratory control lost and arrest soon follows.
What may be the only early sign of increased ICP in peds patients?
Changes in behavior
Signs of inadequate CBF (cerebral blood flow)?
Vision changes
Syncope
What are signs of cerebral edema?
Headache to decreased LOC
Focal (specific areas of brain) neurons deficits
What is vasogenic cerebral edema?
Most common type
Blood brain barrier disrupted and allows large molecules to enter brain tissue
What is cytotoxic cerebral edema?
Brain cell membranes disrupted and leak. Loss of cellular function
From lesions or trauma
What is interstitial cerebral edema?
Usually from hydrocephalus (too much fluid on brain)
Ventricles too large
From too much CSF production, obstruction or can’t reabsorb it
What is treatment for preemies with hydrocephalus?
Ventriculostomy OR
Ventricular shunt
What is Cushing’s Triad?
Bad sign of increased ICP and imminent herniation
This is an emergency!
1. Systolic HTN and widening pulse pressure
2. Bradycardia with bounding, full pulse
3. Irregular respirations
S/Sx of increased ICP
Changes to LOC
Cushings Triad
Visual changes
Decreased motor function
Headache
Vomiting (without nausea is called unexpected vomiting)
What vision changes can happen in increased ICP?
Pupil dilation, sluggish to light or no change to light, inability to move eyes around, blurred vision, diplopia, ptosis
What eye change is an emergency and indicates herniation?
Fixed, unilateral, dilated pupil
What changes in motor function indicated increased ICP?
hemiparesis
hemiplegia
decorticate
decerebrate (worse)
Why is lumbar puncture contraindicated in increased ICP?
Cerebral herniation could occur from sudden release of CSF pressure
What is gold standard for monitoring ICP?
Ventriculostomy
What is a ventriculostomy?
Catheter inserted in lateral ventricle
External transducer measures pressure
What can be done with a ventriculostomy?
Remove and obtain samples of CSF
Drug admin
Measure pressure in brain
What is important to remember about the placement of the transducer of ICP monitoring?
Must be level with tragus of ear.
This is the little raised spot in front of of your ear canal opening,
Has to stay there to read the pressure correctly
ICP monitoring system has monitor paper and strip like EKG. What are the normal waves on ICP paper? What will they look like?
P1 P2 P3
they will look like a downward staircase
What is the patient at high risk for in ICP monitoring?
Infection
Especially is >5 days
If ventriculostomy is in place
If there is a CSF leak
If there is an active infection elsewhere
What does normal CSF look like?
Infection sign?
Clear, colorless, odorless
Cloudy=infection
How is CSF removed with ventriculostomy?
Caution in removal of CSF?
Usually intermittently for 2-3 min every hour. (this will be dr order)
Or can be continuous
Removal must be done slowly to prevent large shift of pressure and herniation
ICP patient needs HOB at what?
Exactly 30 degrees
How much CSF is made hourly?
Total volume in body?
20—30 ml
150 ml
What do LICOX and Neurovent catheters do?
Measures brain oxygenation and temp
Placed in white matter
What does jugular venous bulb oximetry do?
Placed in jugular vein and measures brain oxygenation
What is effect of Mannitol on ICP?
What is effect of hypertonic solutions on ICP?
Decreased ICP through diuresis
Same as Mannitol
Usually these are used together
When are corticosteroids used to treat increased ICP?
Complications in steroid use?
Not in trauma
Edema around tumors or abscesses
Complications are hyperglycemia, infections, GI bleeding.
Will be given H2 receptor blocker and PPI to combat
What metabolic demands do we need to reduce in increased ICP?
Fever
Agitation
Shivering
Pain
Seizures
All these increase ICP
Why is nutrition so important for patients with cerebral edema?
Malnutrition worsens edema
Three basic categories of GSC
Verbal
Motor
Eyes
When a patient has a GCS of 8 or < what should be considered?
Need help maintaining their airway
What is the doll’s eye reflex test?
Hold eyelids open
Turn their head right>eyes should go left
Turn their head left>eyes should go right
Turn down>eyes go up
Turn up>eyes go down
Abnormal response indicate brain stem injury or problems with CN 3, 4, 6
Why is squeezing of hand not an accurate way to test muscle strength?
Because wrapping hands around an object is a reflex
Have them squeeze and release to get an accurate assessment
What are Cheyne-Stokes?
Cycles of hyperventilation>apnea
What is central neurogenic hyperventilation?
Sustained regular and rapid deep breathing
Means brainstem damage
What is apneustic breathing?
Long slow inspirations
Expiratory pauses
What is ataxic breathing?
No pattern
What is med of choice for sedation in increased ICP?
Propafol
Short half life means you can bring them out of sedation easily to do neuro assessment
What two complications can occur with fluid balance in brain injury patients?
Diabetes insipidus
SIADH
This is because of hypothalamus damage
How should a patient with ICP be turned?
Carefully and slowly
No sudden shifts in ICP (especially if drain is in)
Movement raises ICP
What are signs of basilar skull fracture?
What is contraindicated?
Battle sign (behind ears)
Raccoon eyes
NG tube is a no
When there is a CSF leak, what is patient at high risk for?
Meningitis
ABx given prophylactically
What is halo or ring sign?
Indication of CSF leak.
Fluid from nose or ear is collected on 4x4.
Within a few minutes blood centers and CSF fluid forms a ring around blood.
What is the difference between a diffuse and focal head injury?
Diffuse=More than one area (concussion or diffuse axonal injury)
Focal=Specific area (hematoma or contusion)
How are brain injuries classes as major, moderate, minor?
GCS
Severe=3–8 GCS
Moderate=9—12
Minor=13—15
What is a concussion?
S/sx?
Tx?
Minor diffuse head injury
Sudden transient mechanical head injury
Disrupts neural activity
Results in change of LOC
S/sx: Brief loss of consciousness
Amnesia around event
Headache
Tx: Resolves on its own
If loss of consciousness was <5 min they are discharged
What is post concussion syndrome?
2 weeks to 2 months after concussion they have persistent headache, lethargy, personality and behavioral changes, short attention span, brain fog, short term memory problems
What is diffuse axonal injury?
S/sx?
Severe type of diffuse injury
90% stay vegetative after injury
Widespread damage and disconnections of axons.
Takes 12–24 hours to develop after injury
S/sx: Decreased LOC
Increased ICP
Decorticate or decerebrate posture
Global cerebral edema
What rarely happens in kids with a concussion?
Loss of consciousness
What are brain lacerations?
Tearing of brain tissue, usually will have fracture or penetrating injury
What is a brain contusion?
Bruising to focal area, usually from closed head injury or linear fracture
Epidural hematoma?
Classic signs?
Bleeding between dura mater and skull
Emergency>surgery necessary
Usually caused from fracture that opened up an artery or vein
S/sx: Classic: Initial loss of consciousness, brief lucid interval, then decrease in LOC
Other: headache, N/V
What is a subdural hematoma?
Types?
S/sx?
Bleeding between dura mater and arachnoid layer
Usually slower to manifest because usually venous, can be arterial, but usually venous
Acute: 1-2 days
Subacute: >2 days
Chronic: Weeks, months
S/sx: Decreased LOC, headache, pupil changes
Diagnostic tool used to see brain injury?
CT scan
Cranial surgeries performed?
Craniotomy (open piece of skull, create flap)
Burr-hole openings (this is faster than a craniotomy if in emergency)
Cranioectomy (excision into cranium to cut away bone flap)
Emergency tx of head injury?
ABCs
Stabilize C spine
O2 with NRB
2 large bore IV
Keep warm
Neuro assess frequently
Assess for CSF leaks
Fluid balance-don’t overload so ICP stays low
While discharging pt after head injury, educate they should always call dr if…?
Extreme drowsiness
N/V
Worsening headache/stiff neck
Seizures
Vision changes
Behavior changes
Motor problems
Sensory changes
HR <60
What is meningitis?
Acute inflammation of meninges
Usually occurs in fall, winter
2 types: viral and bacterial
Mandatory reporting to CDC
S/Sx of meningitis?
Fever
Severe headache
N/V
Nuchal rigidity (neck stiffness)
Photophobia
Decreased LOC
Skin rash (if from meningococcal bacteria)
Petechaie
Usual culprits in bacterial meningitis?
Strep
Neisseria meningitidis
Medical emergency!
Start ABx right away
Usually they gain entry through upper respiratory or bloodstream
Complications of bacterial meningitis?
Increased ICP
Residual neuro dysfunction like:
Damage to many different cranial nerves
Blindness/Deafness
Vision damage
Ptosis
Diplopia
Unequal pupils
Dysphagia
Hemiparesis
How is bacterial meningitis diagnosed?
Lumbar puncture
CT
Blood culture
CBC (Neutrophils will be high)
What type of isolation in meningitis?
Airborne isolation
Biggest difference in tx in bacterial and viral meningitis?
Viral runs its course and full recovery expected
Tx is supportive
What is encephalitis?
S/sx?
Inflammation of brain
Serious and sometimes fatal
Usually viral
Usually from mosquitos or ticks
S/sx: Fever, headache, n/v, changes in LOC, any CNS problem can manifest
Early signs of hydrocephalus?
Rapid head growth
Full, bulging anterior fontanelle
Irritabilty
Poor feeding
Wide, separated cranial sutures
Distended scalp veins
