HEAD INJURIES AND HYPOTHERMIA Flashcards
What contributes significantly to the death of approximately half of all trauma victims?
TBI
The leading causes of TBI or Endocranial Hemorrhage include what?
- Motor vehicle collisions
2. Falls in the elderly
What is the outermost layer of the head with many layers that include the following?
- Skin
- Connective tissue
- Galea aponeurotica (tick fibrous layers provide structural support)
- Periosteum
Scalp
What includes the following?
- Foramina (small openings for blood vessels and nerves to pass)
- Foramen magnum (brain stem and spinal cord)
- Provides protection to the brain
Skull
What are the layers that cover the brain?
Meninges
- Dura mater inside the skull, tough fibrous layer, Epidural space (potential
space) - Pia mater – closely adhered to the brain
- Arachnoid membranes layered on top of blood vessels adhered to pia
The brain is surrounded by about how much CSF which is produced in the ventricular system and functions to cushion the brain?
150ml
Brain tissue, blood, and CSF exert a pressure within the brain, which is referred to as what?
Intracranial Pressure (ICP)
What is the portion of the dura mater between cerebrum and cerebellum?
Tentorium cerebelli
True or False
Cranial nerves originate from the spine
False
Cranial nerves originate from the brain stem
What cranial nerve controls pupillary constriction, crosses surface of tentorium; hemorrhage or edema that leads to herniation of the brain will compress the nerve leading to pupillary dilation?
Cranial nerve III (oculomotor)
(Systole + Diastole x 2/3) or Diastole + 1/3 pulse pressure equals what?
Mean Arterial Pressure (MAP)
What is used to characterize pressure driving into the brain?
MAP
What is the amount of pressure it takes to push blood through cerebral circulation, to maintain oxygen and glucose delivery?
Cerebral Perfusion Pressure (CPP)
Relates to blood pressure and ICP
MAP - ICP equals what?
Cerebral Perfusion Pressure (CPP)
What is the normal CPP?
70-80mmHg
sudden increase or decrease will alter perfusion
Cerebral Vessels respond to changes in CO2, elevated levels leading to ___ and decreased levels causing ___
- Vasoconstriction
2. Dilation
What is direct trauma to the brain such as contusions, hemorrhages, lacerations or direct mechanical injury?
Primary brain injury
What refers to ongoing injury processes set in motion from primary brain injury?
Secondary brain injury
These are all what types of brain injury?
- Mass effect - elevated ICP (can lead to herniation)
- Hypotension
- Predictors of poor outcome
a. amount of time with ICP > 20mmHg
b. time spent with systolic BP <90mmHG, single episode of hypotension can lead to worse outcome - Hypoxia
- Hypo/hyperglycemia
- Watch for and treat seizures
Secondary brain injuries
___ to ___ % of TBI patients have concomitant C-spine injury which can affect the patient’s ability to properly ventilate
2-5%
The following refers to what reflex?
- Increased ICP can lead to cardiovascular changes
- hypoxic brain leads to vasoconstriction and subsequent stimulation of sympathetic nervous system in an effort to raise BP
- therefore parasympathetic nervous causes slowing of the heart rate in response
Cushings reflex
What refers to the elevated systolic BP, bradycardia, and abnormal respirations (Cheyne-stokes)?
Cushing’s triad
The primary assessment includes what?
- Airway
- Breathing
- Circulation
- Disability
True or False
Once life threatening injuries have been managed, if time permits or during the transport, perform a secondary assessment
True
What should you suspect is there is CSF drainage or delayed (several hours) findings of periorbital ecchymosis or battle signs are seen?
Basilar skull fracture
Trauma to the eye and orbit must be considered with facial trauma and you should evaluate for what?
- Hyphema
- Open globe - signs include teardrop pupil, sub conjunctival hemorrhage, decrease in vision
If suspected, do not apply pressure to the eye and place a protective shield over the eye
What is a head injury from a blow, hit, or jolt to the head that may:
- Briefly knock you out OR
- Affect your ability to remember info before, during, or after the event (post traumatic amnesia) OR
- Makes you feel dazed, like you had your bell rung
- Also known as a mild TBI
Concussion
What is bleeding between the skull and the Dura Mater, occurs in 1-2% of TBI patients, usually from low velocity blows to the temporal bone?
Epidural Hematoma
The pathognomonic history of what is a patient that has had head trauma with a brief period of LOC, regains consciousness (lucid interval), then rapidly declines?
Epidural Hematoma
What accounts for 30% of severe brain injuries from the following?
- MVC, falls
- Results from venous bleed
- Bridging veins torn during blow to head
- Blood collects between Dura and Arachnoid membrane
- Typically results from the rapid accumulation of blood in the subdural space and rapid onset of mass effect
Subdural Hematomas
What is bleeding that occurs between the arachnoid membrane and commonly associated with ruptured cerebral aneurysm and onset of the worst headache of their life and post trauma is the most common cause?
Subarachnoid Hemorrhage
True or False
ALL suspected TBI should receive supplemental O2
True
over 95% spo2
Blood loss and ____ are important causes of secondary brain injury
Hypotension
Circulation with Head injuries
Maintain systolic pressure between ____ mmHg and ____mmHg with IV/IO access and crystalloids
90-100mmHg
After mild TBI/concussion there is a ___ hour minimal recovery period
24 hour
Concussion and Mild TBI
If any red flags such as what are present then you need to refer to a higher echelon of care and consider urgent evacuation?
- Deteriorating level of consciousness
- Double vision
- Increased restlessness, combative, or agitated behavior
- Repeated vomiting
- Seizures
- Weakness or tingling in arms or legs
- Severe or worsening headache
- Unsteady on feet
- One pupil larger or smaller than the other
- Changes in hearing, taste or vision
- Repeated episodes of blacking out or passing out
What are the steps following a suspected concussion or mild TBI?
- Conduct MACE2
- Look for red flags
- Initiate mandatory 24 hour rest
- In the initial 24 hours manage symptoms to facilitate rest and sleep
- Use Tylenol every 6 hours, for 48 hours, after 48 hours, may use naproxen. AVOID Tramadol, Fioricet, and Narcotics
- Reevaluate after 24 hours
- Conduct Neurobehavioral Symptom Inventory (NSI) Screening
If a patient is symptoms free during exertional testing and this is their first concussion in the past 12 months then what should be done?
Return to duty
If symptom free during exertional testing and this is their second concussion in the past 12 months then stay at stage ___ light routine activity for the next ___ days and then perform NSI screening questionnaire daily
- Stage 2
2. 5 Days
What routine activity is this?
- You may wear uniform and boots
- May perform these activities no longer than 30 minutes - walk, stretch, ride a stationary bike at a slow pace with low resistance, no light house work, use the computer, play simple games such as cards
- DO NOT: drink, play video games, do resistance training or repetitive lifting, do sit ups, push ups, or pull ups, go to crowded areas where you may be bumped into
Stage 2 light routine activity
True or False
If symptom free following 5 days of Stage 2 activity then may progress through Stages 3, 4, and 5 (each for 24 hours) and if symptom free following this progression, then perform Exertional testing and if symptom free after exertional testing then may return to full duty.
True
What activity routine is this?
- May perform the following activities for no longer than 60 minutes: lift
and carry objects less than 20 lbs. take a brisk walk, ride in care and look
around, use an elliptical machine or stair climber, perform light military
tasks such as cleaning equipment - May perform these activities no longer than 30 minutes: shop for one item at the store, talk to someone as you walk, gently increase your exposure to light and noise, perform a maintenance check on a vehicle
- DO NOT: Drink alcohol, drive, play video games, do resistance training
or repetitive lifting, go to crowded places, participate in combative or
contact sports
Stage 3 light occupation-oriented activity
What activity routine is this?
- You may wear personal protective equipment
- You may perform the following activities for no longer than 90 minutes:
take a brisk walk, do light resistance training, participate in non-contact
sports, perform moderate job-related tasks, climb, crawl, or jog - You may perform these activities for no longer than 40 minutes: play
video games, foosball, putting and ping-pong, play strategy games such as chess or Sudoku, shop for groceries, perform target practice, drive in a
simulator - DO NOT: Drink alcohol, participate in combative or contact sports, drive
Stage 4 Moderate Activity
What activity routine is this ?
- Resume normal routine and exercise, participate in normal military, training and social activities, use night vision goggles, take part in
simulations, or be exposed to bright light, start driving again, do heavy
job-related tasks, such as digging, communicate by signals during patrol
duty or use radio communication - DO NOT: drink alcohol, participate in combative or contact sports, go
outside the wire in a combat zone
Stage 5 Intensive activity
True or False
Concussion/Mild TBI
If symptoms develop/return during any of the above stages then go back to stage 1 (Rest), provide symptom management, refer to rehabilitation provider for daily monitored progressive return to activity processes
True
If there are 3 or more documented concussions and/or TBI in the past 12 months then stage 1 rest and refer to ___ for a comprehensive work up with imaging and assessment.
Neuro
What is a tool that assists providers in the assessment and diagnosis of a concussion and is most effective when used as close in timing to the time of the incident?
Military Acute Concussion Evaluation Exam 2 (MACE2 exam)
Prior to performing the MACE2 Exam evaluate for any of the following red flags and if present what is the next step ?
- Deteriorating LOC
- Diplopia
- Increasing combativeness or restlessness
- Repeated vomiting
- Seizures
- Weakness or paresthesia’s in extremities
- Severe/worsening HA
Defer exam, MEDEVAC/MEDADVICE
The Mace2 Exam consists of __ steps and takes approximately ___ minutes to complete
- 17 steps
2. 15 minutes
What is defined as a core temperature below 95 degrees F?
Hypothermia
What is defined as mild hypothermia?
90-95F
What is defined as moderate hypothermia?
82-90 F
What is defined as Severe hypothermia?
Below 82F
What is the following?
- Normal mental status with shivering
- Functioning normally
- Able to care for self
- Estimated core temp 35 - 37 C (95 to 98.6F)
Cold Stressed (not hypothermic)
What is the following?
- Alert, but mental status may be altered
- Shivering present
- Not functioning normally
- Not able to care for self
- Estimated core temp 32-35 C (90-95 F)
Mild Hypothermia
What is the following?
- Decreased level of consciousness
- Conscious or unconsciousness, with or without shivering
- Estimated core temp 28 to 32 C (82 to 90F)
Moderate Hypothermia
What is the following?
- Unconscious
- Not shivering
- Estimated core temp <28C (<82F)
Severe/Profound hypothermia
What is generated by cellular metabolism ( most prominently in the heart and liver ) and lost by the skin and lungs ?
Heat
Heat is lost by the skin and lungs via what processes?
- Evaporation
- Radiation
- Conduction
- Convection
What is vaporization of water through both insensible losses and sweat?
Evaporation
What is the emission of infrared electromagnetic energy?
Radiation
What is direct transfer of heat to an adjacent, cooler object?
Conduction
What is the direct transfer of heat to convective currents or air or water?
Convection
What are the most common mechanisms of accidental hypothermia?
Convective heat loss to cold air and conductive heat loss to water
What form of hypothermia demonstrates tachypnea, tachycardia, initial hyperventilation, ataxia, dysarthria, impaired judgment, shivering, and so-called “cold diuresis”?
Mild
What form of hypothermia demonstrates CNS depression, drop in heart rate and cardiac output, hypoventilation, and hyporeflexia and at lower ends of temp, loss of shivering, dysryhtmias (A fib), and dilated pupils
below 29ºC?
Moderate
What form of hypothermia demonstrates Pulmonary edema, oliguria, hypotension, bradycardia, ventricular dysrhythmias (V fib/tach/asystole) and the loss of oculocephalic reflexes?
Severe
Hypothermic patients are extremely sensitive to movement and are prone to what?
Arrhythmia
These are lab studies that should be gathered for what kind of patient?
- Fingerstick glucose *
- Electrocardiogram (ECG) * (Osborne Waves)
- Basic serum electrolytes, including potassium and calcium
- BUN and creatinine
- Serum hemoglobin, white blood cell, and platelet counts
- Serum lactate
- Fibrinogen
- Creatine kinase (CK)
- Arterial blood gas, uncorrected for temperature, in ventilated patients
- Chest radiograph (take care to avoid jostling the patient)
Hypothermia
Mild hypothermia is treated with what?
Passive external warming
Moderate and refractory mild hypothermia are treated with what?
Active External Warming
What forms of hypothermia are treated with active internal rewarming and possibly extracorporeal rewarming?
Severe and some cases of refractory moderate hypothermia
