MOD 11 Flashcards
Levels of consciousness from most concious to least concious
alert and oriented
confused
lethargy
obtundation
stupor
coma
Unconsciousness related to death
cerebral death: an irreversible coma or a persistent vegetative state
Brain death: absent cerebral function and unable to maintain physiologic homeostasis
cognition
means thinking skills that include awareness, language calculation and memory
dementia
organic brain degeneration, progressive, untreatable, irreversible decline in mental functiond
delusion
false belief brought about without appropriate external stimuli (unrelated to reality)
delirium
acute reversible state of agitated confusion. Disorientated to time and place with hallucinations usually symptomatic of a disease and is reversible with treatment of the disease can be caused by a high fever
GCS
Glasgow coma score
scale that helps gauge the impact of a wide variety of conditions affecting the patient’s level of consciousness
lowest possible score a patient could receive of GCS
a 3 for none
pathologic posturing
painful stimuli indicate serious brain damage.
abnormal flexion = decorticate
abnormal extension = decerebrate posturing
acute brain damage GSC measures
trauma
vascular injuries
infections
hypoxia
metabolic disorders
decorticate posturing
indicates that there may be damage to the vertebral hemispheres and possible midbrain
limbs point to the core of the body
Decerebrate posturing
usually indicative of more severe damage indicating a lesion in the cerebellum or lower in the brainstem. very poor prognosis
hands point away from body = brain has gone away
Flaccid paralysis
characterized by limp (floppy) unresponsive muscles that cannot contract. Can be caused by infections and toxins or damage to the spinal cord or brain
Blood-brain barrier
a network of blood vessels that allows the entry of essential nutrients while blocking other substances. The blood vessels are lined with endothelial cells that are wedged tightly together creating a nearly impermeable boundary between the brian and bloodstream
The downside to blood-brain barrier
it is so effective at protecting against the passage of foreign substances that it often prevents life-saving drubs from being able to repair the injured or diseased brain
most dangerous outcome of cerebral edema
increased ICP due to brain injury.
what is the most serious complication of a head injury
cerebral edema or bleeding which can result in increased intracranial pressure.
Vasogenic edema
blood-brain barrier damage causes increased capillary permeability. This occurs with conditions that impair the function of the blood-brain barrier and allow the transfer of water and proteins from the vascular space into the interstitial space leading to swollen brain tissue
Cytotoxic edema
the blood-brain barrier remains intact but a disruption in cellular metabolism impairs the functioning of the sodium-potassium pump active transport failure leads to K+ loss and Na+ retention increasing cellular H2O which leads to ischemia of brain tissue and necrosis of brain cells.
Treatment for cerebral edema
position the patient with the head of the bed elevated 30 degrees
Hypertonic IV fluids pull fluid out of the brain (hypertonic saline and mannitol)
Diuretics- medication to increase the production of urine, and help reduce fluid overload
corticosteroids- suppress the inflammatory response and reduce swelling in the brain
surgical decompression- removing part of the skill allows the brain to swell without being compressed
Increased intracranial pressure (ICP or IICP)
include rise in cerebrospinal fluid pressure, increase pressure within the brain matter, bleeding in and around the brain, swelling.
the pressure can damage the brain or spinal cord by pressing on important brain structures
Early signs of ICP
decreased LOC
pupil changes: perrla (pupils equal, round, reactive to light, and accommodation)
vision abnormalities
headache
vomiting
nuchal rigidity- stiff neck
late sign of ICP
impaired reflexes
papilledema (optic disc swelling)
abnormal posturing (decorticate/ decerebrate)
Cushing’s triad
hypertension (widening pulse pressure- difference between the systolic and diastolic b/p increases)
bradycardia
hypoventilation leading to hypercapnia which causes vasodilation
Primary brain injury
focal injuries- contusions, hematoma’s
diffuse injuries- concussions; diffuse axonal injury; traumatic subarachnoid hemorrhage
secondary brain injury
cause damage to parts of the brain that were not initially injured
damage caused by the inflammation process
swelling leads to ICP leads to brain herniation leads to tissue necrosis
S/s of head injury and TBI
loss of consciousness
headache
vomiting
drowsy
confusion
seizure
drowsiness
restlessness
agitation
LOC changes
contralateral hemiplegia
ICP signs of herniation
check for what with a head injury and TBI
fluid draining from ears and or nose with a glucometer for the presence of glucose
Points to remember with a head injury and TBI
H.I can result from a ground level fall, especially in the elderly
assume “C-SIPINE INJURY” will occur with any H.I. (do not move injured person)
Nursing care for H.I. and TBI
frequent assessment of LOC (using GCS) keep patient’s head elevated 30 degrees to prevent intracranial pressure
NOTE: an order that reads: HOB 30 degrees means “keep the head of the bed up 30 degrees”
protect airway keep suction equipment at patient’s bedside due to vomiting
Concussion
no gross pathology
possible transient loss of consciousness
CT scan is normal
Post-concussion syndrome s/s are headaches and memory lapses
contusion
bruising of the brain surface underneath a fracture or at the under-surface of the frontal temporal lobes, due to shearing forces. diagnosed on ct scan.
Laceration
tearing of the brain substance.
diagnosed by ct scan
Brain/cerebral edema
this is localized in the glial cells, myelin sheaths, and intercellular spaces. it causes increased intracranial pressure, which may impair brain circulation, or result in brain herniation, it may be missed in early CT scans. Later CT scans or MRI show edema more reliably
Herniation
displacement of brain tissue towards the other side of the brain which increases pressure on the non-injured side. the further the brain tissue has herniated “passed midline” the worse the prognosis
Acceleration-deceleration head injury
“coup-contrecoup” hitting both front and back of the head results in brain conditions and hematomas (more than one injury from the same blow)
Cerebrovascular infarction
focal brain necrosis due to complete and prolonged ischemia that affects all tissue elements (neurons, glia, and vessels) in every infarct, there is a central core of total ischemia and necrosis, which is irreversible
Epidural hematoma
blood clot that forms between the skill and the top lining of the brain (dura) this blood clot can cause fast changes in the pressure inside the brain. Usually an arterial bleed so can expand very quickly.
early sign of epidural hematoma
Ipsilateral pupil dilation (dilation of pupil on the same side as the brain hematoma)