Disorders of Consciousness - Exam 3 Flashcards
What is consciousness?
Consciousness is a state of awareness to environment and self with a responsiveness to stimuli
aka you know where and who you are
How is consciousness achieved and maintained?
Via action of the neurons that make up the Ascending Reticular Activating System (ARAS) in the brainstem and cerebral cortex
What makes up the reticular system?
Ascending reticular activating system (ARAS)
Descending reticulospinal tracts
Where does the ARAS originate? Where does it go? What does it control?
originates in the upper pons and midbrain
projecting to the thalamus and hypothalamus and extending to the cerebral cortex, controlling levels of alertness
Where does the descending reticulospinal tract travel? Does it affect consciousness?
travels downward into the spinal cord and modulates spinal reflex activity
does NOT affect consciousness
What does damage to the descending reticulospinal tract lead to?
Damage leads to loss or diminished reflexes
________ is the outer layer of the cerebral hemispheres consisting of grey matter and controls the content of consciousness. What is it responsible for?
Cerebral cortex
self-awareness, language, reasoning, spatial relationship, integration and emotions
What is the difference between consciousness and unconsciousness?
conscious: Awake, aware, alert and RESPONSIVE to stimuli with FAST neuronal activity
unconscious: unaware and unresponsive to stimuli resulting from damage to the ARAS and/or the cerebrum with DIMINISHED transmission of signals from the ARAS to the cerebrum
**What are the 5 levels of consciousness?
What is included in the primary survey of an unconscious patient? Then what do you do?
Circulation
Airway
Breathing
then vitals and secondary survey
aka need to check pulse and then get vitals
What are the first 4 steps in the evaluation of the unconscious patient?
primary survey
vital signs and secondary survey
brief history
initial PE: any evidence of trauma? neuro eval, glasgow coma score
What is included in circulation when talking about the primary survey?
circulation is check pulse
then BP
then is the rhythm regular?
What do you do if a pt does NOT have spontaneous respiration or ineffective respirations? What step? what survey?
need to provide assisted ventilation with bag-mask with supplemental oxygen +/- intubation with vent support
Airway breathing of the Primary survey
**What is the normal range for MAP? How do you calculate MAP?
70-100
What is considered severe hypertension is terms of MAP? What is considered hypotension?
MAP> 130mmHg
hypotension MAP less than 70
If MAP is less than 70, what do you do?
give fluids first then vasopressors to try and raise BP
Why would an ammonia level be high in an unconscious patient?
high ammonia makes you think cirrhosis of the liver
What are the 3 initial managements you need to consider EARLY on when the cause of unconsciousness is not known?
**What extra step needs to be taken when administering thiamine? What vitamin? What dz are you trying to treat?
Administer before or with glucose
vit B1
Wernicke encephalopathy
When evaluating the unconscious patient, _____ is super important. Give the 3 options
timing!
abrupt
gradual
fluctuating
What does abrupt timing of unconsciousness make you think? (give time frame) gradual? (give time frame) fluctuating?
abrupt: subarachnoid hemorrhage, seizure, cardiac arrhythmia
abrupt is measured in seconds
gradual: infectious, space occupying lesion
gradual is measured in hours to days
fluctuating: recurring seizures, subdural hematoma, metabolic disorders
What does unconsciousness with focal neurologic changes make you think?
structural lesion with mass effect or stroke
What does unconsciousness with HA and vomiting make you think?
intracranial hemorrhage, increased ICP
What does unconsciousness with palpitations/chest pain/SOB make you think?
arrhythmia
What does unconsciousness with fever or recent illness make you think?
infection/sepsis
What does unconsciousness with recent confusion/delirium make you think?
metabolic process, drug, alcohol, poison
What does unconsciousness with dizziness/lightheaded make you think?
hypotension, stroke, arrhythmia, hypoxia
What is the empiric treatment for unconsciousness, febrile and possible infection?
ceftriaxone and vancomycin
acyclovir
What is the empiric tx for unconsciousness due to BZD overdose? What do you need to make sure of? Why?
Flumazenil
they have a positive history of BZD overdose because flumazenil is dangerous because it can induce seizures
What is the empiric tx for unconsciousness due to possible poison ingestion? What is the associated timeframe?
Gastric lavage/activated charcoal
only within the last hour
What is the empiric tx for unconsciousness due to increased intracranial pressure?
Glucocorticoids
Mannitol
Position head of bed elevated 30°