Neurological Disorders - Trauma Flashcards
What defines a Primary head Injury
An injury that occurs as a result of initial direct Injuries, and direct force applied to the head. Includes tissue and vascular damage
What is a secondary Head injury
Occurs as a result of hypoxia, decreased perfusion, cerebral edema, infection and hemorrhage
What is the initial response to brain bruising
Vasodilation and increased blood flow to the area of injury. Increased intra cerebral pressure surrounding the site, then decreases blood flow.
How does a normally functioning brain adjust to the O2 and CO2 concentrations
Changes in the concentration of O2 and CO2 in blood and CSF activate chemoreceptors. Impulses are sent to the respiratory center to increase or decrease respiratory rate
What is Intracranial Pressure?
The pressure inside the cranium as a result of brain tissues, blood and CSF
What is the normal intracranial pressure
5-15mm hg, 15 is upper limit of normal
What is the cerebral Perfusion Pressure?
The pressure needed to maintain blood flow to the brain
What is the normal cerebral perfusion pressure level. What happens if it lowers too much?
70-80 mmHg, if it drops below 60mmHg, the chances of death are doubled
What does MAP stand for, and what is the normal range
Mean arterial pressure, 70-100mmHg. less than 60 is deadly for main organs
What does CPP= MAP- ICP mean?
Cerebral perfusion pressure is equal to mean arterial pressure subtract intracranial pressure
What happens when ICP=MAP
blood flow stops
What are the early signs of ICP
CSF is shifted to spinal cavity and decreased cerebral blood flow (effective short term then hypoxic)
What are the early physical S/S of ICP
Severe headache, Vomiting (projectile), Papilledema (swelling of optic disc and ICP), seizures. S/S increase in severity
What is Crushing’s reflex
A neurological response to increased ICP. bradycardia, increased systolic pressure, irregular respirations. Goal is to increase blood supply to the brain
How is ischemia relieved in the brain
Systemic vasoconstriction (^ BP), baroreceptors in carotid arteries respond by slowing the HR. chemoreceptors respond to low co2 by slowing respirations. Improved circulation relieves ischemia by lowering ICP - as ICP increases again system repeats.
What happens when Crushing’s response can not keep up?
As ICP continues to rise, the mechanism can not keep up. If the pressure rises to a critical point where perfusion is impossible, deterioration and death occurs
What happens if severe ischemia and elevated ICP is not fixed
severe ischemia and neuronal death prevent circulatory control and BP drops, Resp control is destroyed= irregularity, death is inevitable.
What is cerebral herniation syndrome?
Brain swelling forces tissues downward through the foramen magnum (space in skull connecting to spinal cord). Places pressure on the brain stem
Signs and Symptoms of cerebral herniation syndrome
decreased LOC, coma, dilated pupil on same side, paralysis on opposite side, decerebrate posturing, hypertension, bradycardia
What is the treatment for Cerebral herniation syndrome
hyperventilation, one breath every 3 seconds
Why do scalp injuries appear worse than they are? How are they treated
The tissue is vascular, and bleeds significantly. Treated with direct pressure (if no skull injuries)
What should you do in respect to skull injuries
Suspect injury with large contusion, leave protruding objects in place, transport immediately.
What are 6 types of brain Injuries (CCCCAD)
Concussion, cerebral contusion, closed head injuries, contrecoup, anoxic brain, diffuse axonal injury
What is a Contrecoup Injury?
A brain injury where the brain is injured on the opposite side of point of trauma
What history and S/S are associated with a Concussion
Mild blows to the head causing excessive brain movement. Reversible, but brief disruption of neural function (Loc, confusion, amnesia). S/S; headache, dizziness, tinnitus, nausea.
What is a cerebral Contusion
bruised brain tissue with ruptured small blood vessels. Swelling may be rapid and severe
Signs and symptoms of Cerebral Contusion
Prolonged unconsciousness, altered LOC, personality changes, profound confusion, persistent amnesia, abnormal behavior, focal neurological signs
What is a basilar fracture and what is a distinctive sign
Fracture at the base of the skull, often accompanied with CSF leaking through ears and nose. Dark discoloration around eyes and behind ears
What is a depressed skull fracture
Displacement of a piece of bone below the level of the skull, compressing brain tissue. Impaired blood supply, high ICP
Diffused Axonal Injury
Most common head injury caused by severe blunt trauma. Diffuse (large area) injury. Stretching, shearing, tearing of nerve fibers from brain moving back and fourth
Complications of a Diffuse Axonal Injury
generalized edema, subarachnoid bleeding, with irritation to surrounding tissues, herniation syndrome possible, often results in permanent vegetative state. S/S; seizure, coma, vomit
What is an Anoxic Brain injury
lack of oxygen to the brain, decreased perfusion. 4-6 minutes of anoxia is irreversible
What are some events/ injuries that may cause an anoxic brain injury?
cardiac arrest, airway obstruction, drowning
What is a closed head injury?
Injury to brain where skull is not fractured, brain tissue damaged by force, blood vessels may rupture. Contrecoup injuries.
Can spinal cord injuries be temporary?
Yes, they can be temporary or permanent, but nerves in the spinal cord do not regenerate
What causes a spinal cord injury
Results from a fracture or dislocation of vertebrae which stretches, compresses or tears the spianal cord
What kind of spinal injury causes irreversible loss of function below the injury
A complete transection. Partial may allow for some recovery
What has to happen to a compressed spinal cord
it must be relieved quickly, as to maintain blood supply
What is the first stage of a spinal cord injury and what does it include?
Early stage; all neurological activity below injury ceases to function. At cervical level, affects BP control, body temp, bowels/bladder func. May last days to weeks
What is the second stage of a spinal cord injury, and what does it include.
Recovery; gradual return of reflex activity, may have the loss of pain/sensation.
What does a Permanent loss of reflexes from a spinal injury cause
para/quadriplegia
Where is an Epidural Hematoma?
Between skull and Dura
Where is a subdural hematoma?
between the dura and the arachnoid
Where is a sub arachnoid hemorrhage?
between arachnoid and pia
What is an intracerebral hematoma
Bleeding directly into the brain tissues
What causes an epidural hematoma?
Usually results from a fracture, tearing of a meningeal artery, leading to a quick and deadly outcome. ARTERIAL BLEED
Signs and Symptoms of an Epidural Hematoma
head trauma with LOC, lucid interval, and then ^ ICP, rapid death
What causes a Subdural Hematoma
Venous bleed, slower. Associated with injury to underlying brain tissues. More common.
How are subdural hematomas classified?
Acute: diagnosed 24 hours - days later,
Sub-acute: diagnosed over a week
What are subarachnoid hemorrhages associated with?
traumatic bleeding from vessels at the base of brain (aneurysms)
S/S of subarachnoid Hemorrhage
Sudden, severe headache, initially localized but becomes diffuse secondary to meningeal irritation. As bleeding continues, ICP^
What causes intracerebral hemorrhage
Bleeding in the brain (frontal/temporal most common) caused by blunt or penetrating trauma.
S/S of Intracranial hemorrhage
Different based on location, Altered LOA, patterns like CVA, high mortality
What are the general S/S of head injuries ?
seizures, cranial nerve impairment, otorrhea or rhinorrhea (leaking CSF from ears or nose), Otorrhagia (ear bleed), fever.
What is the treatment for head trauma pts
LOC, Airway and ventilation, Circulation, cerebral herniation syndrome (check pupils, decerebrate posture, paralysis, hypertension), Hyperventilate pts
What is the typical End tidal value for head trauma pts?
30-35
What GCS values indicate the severities of head trauma?
Mild: 13-15
Moderate: 8-12
Severe: less than 8
What are the differences between Neurogenic and Hypovolemic Shock?
Neurogenic: bradycardia, warm and dry skin, no significant blood loss, paralysis and loss of spinal reflexes
Hypovolemic: Tachycardia, cool pale diaphoretic skin, evident blood loss, no paralysis
What are the signs of a Basal Skull Fracture?
Racoon’s eyes, Otorrhea (CSF from ears), Rhinorrhea (CSF from nose), Mastoid Bruising
What does deviation in pupil size indicate?
CNS involvement or CNS
What does the deviation of pupil position indicate?
Cranial Nerve involvement
What do fixed dilated pupils indicate?
Cerebral anoxia or brainstem involvement
