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