2 - Head Trauma Flashcards
How is TBI classified?
Mild, moderate and severe
Based on Glasgow Coma Scale (GCS)
Most TBI (80%) are defined as?
This type of TBI is aka?
Mild - GCS 14-15
Concussion
Outcomes of moderate TBI? (GCS 9-13)
Mortality - <20%
Long disability - HIGH
Long term outcomes of sever TBI (GCS 3-8)
Mortality - 40%
Only 10% have a “good” recovery
If youre gonna die from a severe TBI when do you usually do it?
The first 48hrs
Why do brain injuries tend to cause decreased brain perfusion and cellular hypoxia?
CPP, MAP, ICP and systemic factors all work together to regulate blood flow to brain.
With brain injury these factors (autoregulation) are not working which causes the hypo perfusion to occur
CPP, MAP, ICP formula
CPP = MAP-ICP
What is the lower limit of the brains ability to autoregulate cerebral blood flow?
CPP <60mmHg
Tx for traumatic hypotension?
aggressive fluid resuscitation
Injury Leads to ischemia so you must use aggressive fluid resuscitation
If yo dont have an ICP monitor how can you ensure blood flow to brain?
maintain a MAP of >/= 80
Primary brain injuries include?
- Contusion (bruise to parenchyma)
- hematomas
- diffuse axonal injury (inj to axons)
- direct cellular damage
- loss of BBB
- disruption of neurochemical hemostasis
- loss of the electrochemical function
Types of brain hematomas?
Subdural Epidural Intraparenchymal Intraventricular Subarachnoid
What causes secondary brain injuries?
Secondary neurotoxic cascade
- a massive release of neurotransmitters (glutamate) into the presynaptic space w activation of N-methyl…propionic acid
Causes an ionic shift -> mitochondrial damage and cell death/necrosis
How long does the secondary injury last?
Apoptosis caused by the injury has been reported to occur longer than 1 yr after injury
The secondary neruotoxic cascade should not be confused with?
Secondary insults
- HOTN, hypoxemia etc
That accelerate damage
Brain edema results from 2 distinct processes and can be fatal in TBI, they are?
Cellular swelling (cytotoxic edema)
Extracellular edema (direct damage to BBB)
Pathophysiology of brain edema?
water content rises ICP increases - direct compressive tissue damage - vascular compression-induced ischemia - brain parenchyma herniation - brain death
4 major brain herniation syndromes?
Uncal transtentorial
Central transtentorial
Cerebellotonsillar
Upward posterior fossa
MC brain herniation?
Uncal herniation
- uncus of temporal lobe is displaced inferiorly through medial edge of the tentorium
What causes uncal herniation?
Expansion lesion in the temporal lobe or lateral middle fossa
Uncal herniation s/s?
Ipsilateral fixed and dilated pupil
- compression of CN III -> unopposed sympathetic tone
Contralateral motor paralysis
- compression of pyramidal tract
What causes central transtentorial herniation?
Midline lesions
Less common
Central transtentorial herniation s/s?
Bilateral pinpoint pupils
Bilateral babinski’s sign
Increased muscle tone
Then:
Prolonged hyperventilation
Fixed midpoint pupils
Decorticate posturing
What is cerebelllotonsilar herniation?
When the cerebellar tonsils herniate through the foramen magnum
Cerebellar tonsillar herniation s/s?
Pinpoint pupils
Flaccid paralysis
Sudden death
Upward transtentorial herniation s/s?
Conjugate downward gaze
No vertical eye movements
Pinpoint pupils
GCS down and dirty?
Eye opening 1-4 pts
Verbal response 1-5 pts
Motor response 1-6 pts
Severe 3-8
Moderate 9-13
Mild 14-15
Which GCS score independently correlates w outcome almost as well as the full score?
The motor score
Warning signs for underlying brain injury?
Focal neurologic deficit
Seizures
Emesis
Depressed LOC
If intubation is necessary? (regarding GCS)
Get a preintubation GCS first if you can
In an unresponsive pt
Single fixed, dilated pupil =
Intracranial hematoma w uncal herniation
- rapid surgical decompression
Unresponsive pt
Bilateral fixed and dilated pupils
- Increased ICP
- poor brain perfusion,
- bilateral uncal herniation
- drug effect (atropine)
- severe hypoxia
Unresponsive pt
Bilateral pinpoint pupils
Opiate exposure
Central pontine lesion
Decorticate posturein is?
(Upper extremity flexion and lower extension)
Severe intracranial injury above the level of the midbrain
Decerbate posturing is?
(Arm extension and internal rotation w wrist and finger flexion and internal rotation and extension of lower extremities)
Caudal injury
In a completely unresponsive pt you should assess?
Respiratory pattern
Eye movements
IOT assess brainstem function
Best way to get a CT on an uncooperative or compbative pt?
Intubation and sedation
- you may have to , blood in brain will kill them quickly
Cervical fractures in comatose TBI pts?
Approx 8%
4% are missed on initial assessment (oops)
If a head injury pt is intubated watch out for?
Hyperventilation
- causes cerebral vasoconstriciton
How to prevent hyperventialtion?
Use capnometry to keep PCO2 at 35-45 mmHg
Primary goals of tx for head injury pts in ED?
Cerebral profusion/oxygenation (intravascular volume and ventilation)
Prevent secondary injury
- correct hypoxia, hypercapnia, hyperglycemia, hyperthermia, anemia or hypoperfusion
Recognize and treat elevated ICP
Get neurosurgical intervention
Tx life threats
What is associated with 150% increase in mortality?
Systolic BP <90
Hypoxemia PaO2 <60
S/s of elevated ICP?
Change in mental status Pupillary irregularities Focal neurological deficits Decerbrate/decorticate posturing CT pathology
Sedation and analgesia effects on ICP?
May decrease baseline ICP Prevent transient rises in CIP from - agitation - coughing - gagging (ET tube)
Why does it matter when you catch TBI?
TBI’s are progressive
early management helps prevent
- more cell death
- secondary injury (edema)
Problems with induction agents ?
Etomidate - lower ICP
Propofol - HOTN
Paralytics side effects?
Succinylocholine - short acting but avoid in burns, excessive injury
Rocuronium - short - safe in Hyper K
When treating head injury what trauma management technique can make the patient worse?
Permissive hypotension - can worsen outcomes in pts w brain injury
If fluid resuscitation is not effective?
Use vasopressors to preserve cerebral perfusion
Why is pain management important with head injury?
Pain and increase in ICP can cause hypertension
Treat pain and assess for impending herniation (cushing reflex)
Can/Should you raise the head of the bed?
Raising head may lower ICP
- uncertain if this is beneficial
- currently recommended
Raising the head on a suspected spinal injury pt?
Elevating had of bed 30* can be safely accomplished before spine is cleared as long as head is secured
How does sugar effect neurologic injury?
Hyperglycemia + neurologic injury = worse outcome
tight hyperglycemia control is recommended
- manage w insulin drip
Signs of rising ICP
Severe HA Visual changes Numbness Focal weakness N/v Seizures Change in mental status Lethargy HTN Coma Bradycardia Agonal respiration
Signs of impending transtentorial herniation
- Unilateral or bilateral pupillary dilation
- Hemaparesis
- Motor posturing
- Progressive neurologic deterioration
In patients with rapidly deteriorating GCS you should try to get?
Repeat head CT to ID an expanding intracranial hematoma
Drugs to lower ICP?
Mannitol and or hypertonic saline
How does mannitol work?
Plasma volume expander (works in 30 min)
- can improve O2 carrying capacity
- results in net intravascular volume loss because of its diuretic effect
What constitutes “hypertonic saline”
Whats the dose?
Most ED”s have 3% NaCl
- 250ml over 30 min
If GCS = 8 the pt needs?
Intracranial bolt or extra-ventricular drain w monitoring capabilities
What should you maintain CPP at?
55-60 mmHg
> 70 may result in injury to other organs
What patients should get ICP monitoring with an normal CT scan?
2 or more of:
- age >40
- unilateral/bilateral motor posturing
- systolic <90
ICP > ___ increases morbidity and mortality?
> 20mmHg
Pts with suspected skull fractures need?
Head CT
How are skull fractures categorized?
By:
- location
- Pattern
- open/closed
Factors of skull fractures that have higher complications?
Fx that cross: - the middle meningeal artery, - a major venous sinus, - or linear occipital fx have high intracerebral complication rates
Which skull fractures need IV abx?
Open skull fractures that are:
- open
- depressed,
- involve a sinus,
- associated w pneumocephalus
Abx for Open skull fx?
Vancomycin 1gm IV
And
Ceftriaxone 2gm IV
MC basilar skull fx?
Involves
- the petrous portion of the temporal bone
- External auditory canal
- Tympanic membrane
Basilar fx are associated with?
Dural tearing
- leads to otorrhea/rhinorrhea
Never give an NG tube to?
Basilar skull fx if cribriform plate fx is suspected
S/s of basilar skull fx?
- CSF leak
- Mastoid ecchymosis (battle sign)
- Periorbital ecchymoses (raccoon eyes)
- hemotympanum
- vertigo
- decreased hearing/deafness
- CNVI nerve palsy
Warning sing for CSF leak?
Pt complains of otorrhea or rhinorrhea
How is CSF differentiated from rhinorrhea?
Collect fluid and analyze
- B transferrin
B2 transferrin isoform of transferring is found only in CSF - not blood, mucus or tears
Pts with acute CSF leaks are at risk for?
Meningitis
- give abx prophylaxis
- consult neuro
Preferred abx for CSF prophylaxis?
Ceftriaxone 2gm IV
And
Vancomycin 1gm IV
Cerebral contusions usually occur?
Frontal and temporal lobes
- rarely in the occipital lobes
What is a contrecoup injury?
Contusion that occur at the opposite side of blunt trauma
When do intracerebral hemorrhages occur?
Several days after contusions
- get a series of CT scans and track mental status
How do isolated subarachnoid hemorrhage present?
Headache
Photophobia
Meningeal signs
That really narrows it down
What causes traumatic subarachnoid hemorrhage?
Disruption of the paranchyma and subarachnoid vessels
- presents with blood in CSF
What is the MC CT abnormality in TBI pts?
Traumatic subarachnoid hemorrhage
TBI with subarachnoid hemorrhage prognosis?
3x higher mortality risk
When is a CT scan best for diagnosing subarachnoid hemorrhage?
CT scans 6-8hrs after injury are sensitive for detecting traumatic subarachnoid hemorrhage
What is an epidermal hematoma?
Collection of blood in the potential space between:
- skull
- dura matter
Classic hx for epidural hematoma?
Significant blunt head trauma w LOC/altered sensorium
Followed by a lucid period and subsequent rapid neurologic demise
Trauma -> LOC -> lucid -> crash
What causes subdural hematoma?
Sudden acceleration-deceleration of brain parenchyma w
- tearing of bridging dural veins
Subdural vs epidermal hematoma?
Subdural - collects slowly
Epidermal - collects faster
But:
Subdural hematoma is often associated w concurrent brain inj and underlying parenchymal damage
How does brain atrophy affect subdural hematoma?
Old and alcoholics w brain atrophy are more susceptible to acute subdural hematoma
Who is at a higher risk for subdural hematoma?
Alcoholics
Elderly
Kids <2
Clumsy (even small falls can cause)
When do acute subdural hematomas present?
W/in 14 days of the injury
After 2 weeks becomes chronic
Chronic Subdural pts can be difficult to diagnose because?
They often have no recall of the injury
How do acute and subacute and chronic subdural hematoma’s look on CT?
Acute:
- Hyperdense (white) crescent shaped lesions that cross suture lines
Subacute:
- isodense and more difficult to ID
- contrast may help
Chronic:
- hypodense (dark) - Iron in the blood has been metabolized
Surgery and subdural hematomas?
Acute - surgery
Subacute - surgery
Chronic - no surgery (maybe)
Intracranial injury comparison?
Slide 66
What is diffuse axonal injury?
Disruption of axonal fibers in the white matter and brain stem
- seen after blunt trauma
- MVA, shaken baby etc
CT scan for diffuse axonal injury?
May appear normal
Classic findings:
- punctuate hemorrhage injury along grey-white junction of cerebral cortex and w/in the deep structures of the brain
Tx for diffuse axonal injury?
Tx is limited
Attempt to prevent secondary damage by :
- reducing cerebral edema
- limiting pathologic increase in ICP
Why are bullets more traumatic than other penetrating injury?
They are scary…
But seriously:
- cavitation - creates a cavity 3-4x larger than the bullet itself
- maj of injury is from the kinetic injury
Prognosis of bullet to head?
GCS > 8 - 25%
GCS <5 - 100%
Tx for bullet to head?
Intubate
Prophylactic abx
- vanc 1gm IV
- ceftriaxone 2mg IV
Contrast stab wounds with bullet?
Stab wounds are relatively low energy
- damage is only the area contacted with the penetrating obj
Tx for penetrating trauma?
Broad spectrum abx
Operation
Leave impaled obj in place until surgery
What do you call an elephant that doesnt matter?
An irrelevant
