CNS disorders (Mod 2) Flashcards
What are 6 types of brain/spinal cord injuries?
- Traumatic Brain Injury (TBI)
- Stroke
- Infection (Meningitis, Encephalitis)
- Seizures
- Tumors
- Spinal Cord Injury (Covered in Mod )
What kind of ventilation would you most likely use for a patient with a brain/spinal cord injury?
Pressure support ventilation for spinal cord injury.
- If TBI is suspected, follow TBI protocol
- TBI goals are CO2 35-40 w/O2 goals 80-120
When would you expect Central neurogenic hyperventilation?
Coning
- loss of respiratory drive
- response to reduced CO2 levels in the blood from brain lesions or injury
- Destruction of the brain stem
When would you expect central neurogenic hyperventilation?
- aka causes
CNS lymphoma
- caused by compression of midbrain via edema or trauma
When would you expect Biots breathing?
Episodes of deep inspirations w/periods of apnea
- Damage to the medulla
When would you expect Apneustic breathing?
- Prolonged, gasping inspiration but not effective respirations. Need to bag
- Damage to upper pons
- Poor prognosis
When would you expect Cheyne Stokes Respiration
Associated w/decreased cardiac output (heart failure), central sleep apnea, and damage to respiratory centres
- cycles of gradual increase in rate and volume followed by gradual decrease, then period of apnea
What is the relationship between cerebral blood flow (CBF) and CO2
(slide 6)
Decreased CO2 vasoconstriction brain vessels causing decreased CBF
What is a sign of coning?
Cushings triad
What are ventialtor strategies for brain/spinal injuries?
- Low-normal PaCO2 to decrease CBF and ICP
- Hyperventilation if coning is suspected, can decrease O2 delivery
CPP is compromised of?
MAP and ICP
- CPP = MAP - ICP
Normal ICP?
10-15 mmHg
What happens if ICP is between 15-20?
microcirculation compromised (capillary compression)
What happens if ICP is between 30-35?
Venous drainage impeded
- edema develops in uninjuried tissue
Why do you want to hyperventilate a pt suspected of coning?
Reduce metabolic demand of the heart
is primary or secondary brian injury more likely to cause the diffuse cascade that leads to brain death?
Secondary; continuation of damage following the TBI
what is TBI defined as?
Damage caused to the brain by external mech forces
Mild TBI characteristics?
Glasgow Coma Scale 13-15
- loss of consciousness up to 15 minutes
- Usually recover
Moderate TBI injury characteristics
GCS 9-12
- LOC up to 6 hours, may deteriorate because of rising ICP
- CT scan useful but may not need hemodynamic or respiratory support
Severe TBI characteristics
GCS 3-8,
- LOC over 6 hours, CT scan to identify extent of damage
- Respiratory and circulatory support typically needed
- Combative patients may need to be heavily sedated to acquire a CT scan, necessitating intubation.
Signs and symptoms of Mild TBI injury?
Headache, nausea, vomitting, dizziness, lack of motor coordination, clumsiness, visual disturbances, changes in sleep patterns
signs and symptoms of severe injury?
Loss of consciousness, Dilated pupils (one or both), “blown pupils,” Apnea, Paralysis/Weakness
- Cushion’s Triad (Bradycardia, Hypertension, Irregular respiration)
Decorticate vs Decerebrate
- Decerebrate is more severe; damage to brainstem. hyperextended body.
- Decorticate; damage to cerebrum; arms adducted inward.
What does shifting of the ventricles mean?
shifting of the ventricles; means we’ll see the midline of the brain shift
- treated w/burr hole (cerebral drainage)
- usually occurs when blood is between the layers of the brain
What is a epidural hematoma?
Blood between skull and dura
- Trauma etiology
- Conditino detiorates rapidly as fluid acclimates
- Treated w/burr hole (cerebral drainage)
Treatment for epidural hematomas?
Treated w/Burr hole
What is a subdural hematoma?
Accumulation of blood between dura and arachnoid layers
- Accelration/deceleration injury -> rupture cerebral veins
What is the onset of subdural hematomas (3)
- acute
- subacute
- chronic
- Acute = within 48 hours
- subacute = 3-20days
- Chronic = 20+ days
TBI penetrating head injury characteristics
obvious and lifethreaning
- weapons
- vascualr tearing from object entering skull
- route for infection
TBI diagnostics
- DI (CT and MRI)
- Angiography
- ICU (ICP monitoring, SjvO2, Licox, EEG)
- CT = quick and accurate…MRI = more detailed = better prediction of outcome.
What does SjvO2 reflect?
How much brain tissue is extracting oxygen
- remember, it is measured by the blood leaving the brain
why does seizure activity increase…? (2)
- Increases cerebral metabolic demand
- Increases ICP
What is TBI acute management for a primary injury?
- Transport to neuro treatment center
- Supportive Management-ABC’s
- Surgical Care (craniotomy, burr hole, hematoma evacuation
Surgical care for primary TBI injuries?
- Burr hole -> done emergency
- Craniotomy: planed out, remove a portion of the skull to allow room for edema to happen in the brain grafted under the patient skin to preserve
- Hematoma evacuation-burr hole and a taking catheter and exoculating blood
- Mass excision - removal of foreign objects
- Tissue debridement, getting rid of dead tissue
TBI Acute management for a secondary injury?
- Therapeutic hypothermia
- ICP control
- Maintain MAP to maintain CPP
- Manage cerebral edema
What drugs can be given to maintain MAP or CPP?
FLuids and vasopressors
How is cerebral edema managed?
Mannitol, lasix, hypertonic saline
For Chronic brain injury management, what are some expected complications?
Depends on severity of injury, For higher brain death:
- Tracheostomy and infection management
- DVT and Pressure sores
Rehab for chronic brain injury?
Months to years
- PT
- SLP (speech language pathology)
- Cognitive rehabilitaiton therapy
- Occupational therapy
- Mental health support
How can ICP control be managed?
- Position
- Sedation, anelgesia, paralytics
- Therapeutc hyperventilation (Vent strategy and ABG goals)
- Extra-ventricular drain (EVD)
Define Stroke
Rupture of block of blood vessel in brain
- Deprives brain of blood supply
- Areas of ischemia can be permanently damaged (infarction)
Stroke risk factors
- Age
- Genetics
- Hypertension
- Diabetes
- High cholesterol
- Tobacco use
- Cardiac disease
- Oral contraceptives
How does diabetes increase the risk of stroke
High glucose (hyperglycemia) damages blood vessels
FAST acronym?
S and S for Stroke
- Facial drop
- Arms weakness
- Speech difficulty
- Time to call 911
Signs and symptoms of stroke
Arm weakness (if they can’t keep it up)
- numbers, confusion, vision problems, dizziness, severe headache w/no known cause
- weakness, memory problems, fatigue, nausea, vomiting (more common in women)
- speech difficulty and face drooping
Classification of strokes (6)
- break these up later into separate cards
Ischemic strokes (majority of strokes)
- Thrombotic
- Embolic
- Lacunar
- TIA
- Hemorrhagic
What are Hemorrhagic strokes caused by?
Aneurysms (bulging of vessels that burst)
- weakened area in blood vessel (ballooning)
- If bursts or leaks, bleeds into the brain
- Precipated often by stress/HTN
What are the subdivisions of hemorrhagic strokes?
Intracerebral hemorrhage and Intracranial Hemorrhage