29.6 Head and Hypothermia Flashcards
TBI contributes significantly to the death of approximately how many of all trauma victims
approximately half
Leading causes of TBI
(a)Motor vehicle collisions
(b)Falls in the elderly
Which structure has thick fibrous layers provides structural support
Galea aponeurotica
Which part of the skull has small openings for blood vessels and nerves to pass
Foramina
Which part of the skull allows the brain stem and spinal cord passes
Foramen magnum
portion of dura mater between cerebrum and cerebellum
Tentorium cerebelli
What does CN III control?
controls pupillary constriction
Normal CPP
70-80mmhg. Sudden increase or decrease in CPP will alter perfusion
What is a primary brain injury
(a)Direct trauma to the brain
(b)Contusion, hemorrhages, lacerations or direct mechanical injury
(c)Neural tissue does not regenerate well therefore low expectation of recovery of the tissue associated with primary injuries
What is secondary brain injury
(a)Refers to ongoing injury processes set in motion from primary injury
(b)Primary focus is to limit or stop secondary injury
Types of secondary brain injury
1)Mass effect – elevated ICP (can lead to herniation)
2)Hypoxia (inadequate delivery of O2)
3)Hypotension
2 biggest predictors of poor outcome in head trauma are
a)Amount of time spent with ICP > 20mmHg (usually below 15mmHg) and
b)Time spent with systolic BP < 90mmHg. A single episode of hypotension can lead to a worse outcome
Hypo and hyperglycemia have a profound effect on brain injuries.
a)The brain is unable to store and glucose therefore requires a constantdelivery.
b)In the absence of glucose neurons can become permanently damaged
Cushing’s triad refers
to elevated systolic BP, bradycardia and abnormal respirations (Cheyne-stokes)
This response is known as Cushing’s reflex
a)The hypoxic brain leads to vasoconstriction and subsequent stimulation of the sympathetic nervous system in an effort to raise BP
b)Therefore parasympathetic nervous causes slowing the heart rate in response
Depressed vs non depressed skull fractures
Depressed can often be palpated and may require surgical intervention
suspect if CSF drainage or delayed (several hours) findings of periorbital ecchymosis or battle signs are seen
Basilar skull fracture
What brain injury is the following:
a head injury from a hit, blow, or jolt to the heat that
(a)Briefly knock you out (loss of consciousness), OR
(b)May affect your ability to remember information before, during, or after the event (post traumatic amnesia), OR
(c)Makes you feel dazed, like you had your bell rung (alteration of consciousness)
(d)A Concussion is also known as a mild traumatic brain injury
Concussion
What brain injury is the following:
(a)Bleeding between skull and Dura Mater
(b)1-2% of TBI patients
(c)Usually low velocity blow to temporal bone
(d)Pathognomonic history is patient has head trauma with a brief LOC, regainsconsciousness (lucid interval), then experiences rapid decline in consciousness
(e)Due to the location of the bleed the patient have a great recovery if rapid surgical intervention is performed
(f)Watch for dilated, sluggish non-reactive pupil
Epidural hematoma
What brain injury is the following:
(a)Account for 30% of severe brain injuries
(b)Generally results from venous bleed
(c)Bridging veins are torn during blow to the head
(d)Blood collects between Dura and Arachnoid membrane
(e)Typically results from relatively rapid accumulation of blood in the subdural space and rapid onset of mass effect
Subdural hematomas
What brain injury is the following:
(a)Bleeding that occurs between arachnoid membrane
(b)Many vessels located in this space
(c)Commonly associated with ruptured cerebral aneurysm and onset of worst headache of life. However, post traumatic is the most common cause. Symptoms include:
1)Severe HA
2)Nausea & vomiting
3)Dizziness
4)May have meningeal signs
5)Seizures
(d)Does not cause mass effect due to location therefore surgical intervention is not common.
Subarachnoid Hemorrhage (SAH)
What brain injury is the following:
result in an open fracture with, if the patient survives they pose a high risk for potential infection. Manage airway management and administer antibiotics.
Penetrating cranial injury
Can c-collar be deferred if it compromises airway management
Yes, – manual stabilization continued until collar placed if clinically indicated.
When is controlled hyperventilation done for brain injuries
only used in specific circumstances i.e. signs of herniation (dilated pupil, posturing or no motor response) for short periods of time
After mild TBI/concussion, what is the minimal recovery period
24 hours
Concussion/Mild TBI Red flags
(a)Deteriorating level of consciousness
(b)Double vision
(c)Increased restlessness, combative, or agitated behavior
(d)Repeated vomiting
(e)Seizures
(f)Weakness or tingling in arms or legs
(g)Severe or worsening headache
(h)Unsteady on feet
(i)One pupil larger or smaller than the other
(j)Changes in hearing, taste or vision
(k)Repeated episodes of blacking out or passing out
Steps following suspected Concussion or mild TBI
(1) Conduct MACE 2 examination as close to time of injury as possible
(2) Focus on looking for red flags
(3) Initiate mandatory 24 hour rest period (must be able to explain this to both the patient as well as the commanding officer so that everyone understands the severity and treatment plan)
What restrictions does a patient have during their 24 hour rest period after TBI
(a)Rest with extremely limited cognitive activity (no reading, playing video games,word puzzles, etc.)
(b)Limit physical activities to those of daily living and extremely light leisureactivity
(c)Avoid work, exercise, video games, reading or driving
(d)Avoid caffeine and alcohol
What medications should be used and avoided while treating headaches from TBI
- Use acetaminophen every 6 hours, for 48 hours, after 48 hours, may use Naproxen as needed.
- Avoid Tramadol, Fioricet, and Narcotics.
Initial Concussion Management
(a)In the initial 24 hours, manage symptoms to facilitate rest and sleep
(b)Aggressive headache or pain management
(c)Reduce environmental stimuli
(d)Review current medications and sleep hygiene
(e)Provide concussion education and set expectations for full recovery
When should Neurobehavioral Symptom Inventory (NSI) screening be conducted after a mild TBI
After 24 hours during re-evaluation
What testing should be done after a mild TBI patient is sx free
1)Exertional Testing
a)Exert to 65-85% of target heart rate (THR=220-age) using push-pus, sit- ups, running in place, step aerobics, stationary bike, treadmill, and/or handcrank
b)Maintain this level of exertion for approximately two minutes
c)Assess for symptoms (listed above)
d)If symptoms/red flags exist with exertional testing, stop testing, and consult with provider
If symptom free during exertional testing and this is their first concussion in thepast 12 months then
Return to duty
If symptom free during exertional testing and this is their second concussion in the past 12 months then
stay at stage 2 light routine activity for the next 5 days and perform NSI screening questionnaire daily
Stage 2 light routine activity
a)You may wear a uniform and boots
b)May perform these activities no longer than 30 minutes – walk, stretch, ride a stationary bike at slow pace with low resistance, no light housework, use the computer, play simple games, such as cards.
What should be avoided during stage 2 recovery following TBI
DO NOT: Drink alcohol, 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.
If symptom free following 5 days of Stage 2 activity then may progress through
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.
Which stage of recovery for TBI:
a)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
b)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
c)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
Which stage of recovery for TBI:
a)You may wear personal protective equipment
b)You may perform the following activities for no longer than 90 minutes:take a brisk walk, do light resistance training, participate in non-contactsports, perform moderate job-related tasks, climb, crawl, or jog
c)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
d)DO NOT: Drink alcohol, participate in combative or contact sports, drive
Stage 4 Moderate activity
Which stage of recovery for TBI:
a)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
b)DO NOT: drink alcohol, participate in combative or contact sports, go outside the wire in a combat zone
Stage 5 Intensive activity
If sx develop/ return during any of stages of TBI recovery, what should be done?
Go back to stage1 (Rest), provide symptom management, refer to rehabilitation provider for daily monitored progressive return to activity processes
If 3 or more documented concussions and/or TBI in the past 12 months then
Stage 1 rest and refer to Neurology for a comprehensive work-up with imaging and assessment.
When is the MACE2 most effective?
when used as close in timing to the time of the incident
Prior to conducting MACE2, what red flags should be checked that would initiate MEDEVAC/MEDAVICE
(a)Deteriorating LOC
(b)Diplopia
(c)Increasing combativeness or restless
(d)Repeated vomiting
(e)Seizures
(f)Weakness or paresthesia’s in extremities
(g)Severe/worsening HA
How long is the MACE2
Exam consists of 17 steps and takes appx 15 min to complete
Hypothermia is defined as a core temperature below
95ºF.
Temperature stages of Hypothermia:
Mild
Moderate
Severe
a)Mild - 90-95ºF
b)Moderate - 82-90ºF
c)Severe below 82ºF
Which cold injury?
(1Normal mental status with shivering
(2Functioning normally
(3Able to care for self
(4Estimated core temperature 35 to 37°C (95 to 98.6°F)
Cold stressed (not hypothermic)
Which stage of hypothermia?
(1Alert, but mental status may be altered
(2Shivering present
(3Not functioning normally
(4Not able to care for self
(5Estimated core temperature 32 to 35°C (90 to 95°F)
Mild hypothermia
Which stage of hypothermia
(1Decreased level of consciousness
(2Conscious or unconscious, with or without shivering
(3Estimated core temperature 28 to 32°C (82 to 90°F)
Moderate hypothermia
Which stage of hypothermia
(1Unconscious
(2Not shivering
(3Estimated core temperature <28°C (<82°C)
Severe/Profound hypothermia
Vaporization of water through both insensible losses and sweat
Evaporation
Emission of infrared electromagnetic energy
Radiation
Direct transfer of heat to an adjacent, cooler object
Conduction
Direct transfer of heat to convective currents of 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
S/S of which stage of hypothermia
- demonstrates tachypnea, tachycardia, initial hyperventilation, ataxia, dysarthria, impaired judgment, shivering, and so-called “cold diuresis”
Mild hypothermia
S/S of which stage of hypothermia
(a)CNS depression, drop in heart rate and cardiac output, hypoventilation, and hyporeflexia
(b)At lower ends of temp, loss of shivering, dysrhythmias (A fib), and dilated pupils below 29ºC
Moderate hypothermia
S/S of which stage of hypothermia
(a)Pulmonary edema, oliguria, hypotension, bradycardia, ventricular dysrhythmias.(V fib/tach/asystole)
(b)Loss of oculocephalic reflexes
Severe hypothermia
Hypothermic patients are extremely sensitive to
movement and prone to arrhythmia (VFib)
Lab studies for hypothermic patients
(a)Fingerstick glucose *
(b)Electrocardiogram (ECG) * (Osborne Waves)
(c)Basic serum electrolytes, including potassium and calcium
(d)BUN and creatinine
(e)Serum hemoglobin, white blood cell, and platelet counts
(f)Serum lactate
(g)Fibrinogen
(h)Creatine kinase (CK)
(i)Arterial blood gas, uncorrected for temperature, in ventilated patients
(j)Chest radiograph (take care to avoid jostling the patient)
Dx of hypothermia based on?
Based upon a history or other evidence of environmental exposure to cold and a core temperature below 35ºC (95ºF)
Treatment of hypothermia
(a)ABC
(b)Prevent further heat loss
(c)Rewarming
(d)Treatment of complications
Rewarming techniques for hypothermia
(a)Mild hypothermia is treated with passive external rewarming
(b)Moderate and refractory mild hypothermia are treated with active external rewarming
(c)Severe (and some cases of refractory moderate) hypothermia is treated with active internal rewarming and possibly extracorporeal rewarming
In the largest study, performed over 25 years ago, factors associated with death within 24 hours of presentation included the following
1)Prehospital cardiac arrest,
2)Low or absent blood pressure on presentation,
3)Elevated BUN and
4)The need for endotracheal intubation.
5)Outcome did not correlate with core temperature at presentation
