TBI Flashcards
Relationship between ICP and CPP
CPP = MAP - ICP
MAP = (1/3 SBP) + (2/3 DBP)
As ICP goes up, CPP goes down (less blood going into brain!)
Goal ICP
Avoid ICP >20mmHg
Goal CPP
CPP = blood going into brain
Goal CPP ~60mmHg
After brain injury, __, __, or __ trigger the metabolic cascade. Recall, the impact itself causes [neurotransmitter] to rush out, yielding an imbalance. That imbalance causes ___ to rush into the cell which sends the ion pump into overdrive. This takes energy (aka ___) - so the __ in the cell get overworked, there is an increased need for glucose (to feed the energy cycle), the system is having trouble keeping up and this ultimately leads to cell death.
Elevated __ can perpetuate this cycle.
Medically, we want to slow/stop this cycle!
After brain injury, ISCHEMIA or HYPOXIA, or IMPACT DEPOLARIZATION trigger the metabolic cascade (= a microscopic chemical rxn causing tissue damage).
Recall, the impact itself causes GLUTAMATE to rush out, yielding an imbalance. That imbalance causes Ca2+ to rush into the cell which sends the ion pump into overdrive. This takes energy (aka ATP) - so the MITOCHONDRIA in the cell get overworked, there is an increased need for glucose (to feed the energy cycle), the system is having trouble keeping up and this ultimately leads to cell death.
Elevated ICP can perpetuate this cycle.
Medically, we want to slow/stop this cycle!
Lab values and vitals to watch post brain injury
Na+ (can sometimes trend too high) BUN Creatinine Acidosis Thalamic storming
Sympathetic storming (AKA paroxysmal autonomic instability and dystonia = PAID) can occur [how long?] post injury and involves an increase in ___ nervous system activity. Episodes are [provoked / often unprovoked] . Signs and symptoms include … Pts are at risk for secondary impairments resulting from decreased ___ . Medical mgmt?
Sympathetic storming (AKA paroxysmal autonomic instability and dystonia = PAID) can occur WEEKS post injury and involves an increase in SYMPATHETIC nervous system activity. Episodes are OFTEN UNPROVOKED. Brain goes into “overdrive,” often due to some brainstem damage, anoxic injuries, and more severe DAI. Signs and symptoms include POSTURING, TACHYCARDIA, TACHYPNEA, DIAPHORESIS, and INCREASED BP. Pts are at risk for secondary impairments resulting from decreased CEREBRAL OXYGENATION. MDs try to medically manage this with medications.
With acute brain injury, our goals are survival!
“ABCs”
Manage the __ and __ to prevent secondary injury
With acute brain injury, our goals are survival!
“ABCs”
Manage the ICP and CPP to prevent secondary injury
Glasgow Coma Scale Used with [acute / subacute / chronic] injuries Looks at what 3 areas of function? High score = [more/less] functional? Min score? Max score? Cutoffs?
Glasgow Coma Scale
Used with ACUTE injuries, used in field & ICU
Looks at EYE RESPONSE, VERBAL RESPONSE, and MOTOR RESPONSE
High score = MORE functional
Min score of 3 (that’s BAD!) -> max 15
Mild = 13-15; Moderate = 8-13; Severe = 3-8
=<8 = coma, 3 = unresponsive
(<5 on day 3 post anoxic injury assoc. with poor prognosis)
Limitation: does require verbal response (ie an injury specifically to speech/language centers may score particularly low even if they’re otherwise doing OK)
The FOUR Score is an alternative to the Glasgow Coma Scale that it looks at what 4 areas? What specific condition can it better recognize?
FOUR Score = looks at eye fxn, motor fxn, brainstem reflexes (pupil & corneal), and respiration pattern.
Can recognize Locked In Syndrome
The Ranchos Los Amigos scale is used throughout TBI course and describes behaviors demonstrated at each level.
Describe behaviors at each level.
High or low - which is better functioning?
The Ranchos Los Amigos scale is used throughout TBI course and describes behaviors demonstrated at each level. Can fluctuate between phases at any given time!
Level I = no response = coma
Level II = generalized response to external stim, non-specific, non-purposeful response to stimulus (e.g. lip smacking), often stereotypic and limited
Level III = localized response, responds specifically and inconsistently to stimuli with delays, but FOLLOWS SIMPLE COMMANDS
Level IV = confused and agitated, scared, overreact to stimuli, focused on basic needs; difficulty following directions and engaging; therapeutically, avoid eye contact if need to de-escalate, be overly calm! Safety is first goal. Hard for families at this stage.
Level V = confused, inappropriate, non-agitated; short attention span, needs step by step instructions for basic tasks, overwhelmed by stimuli, confabulate, perseverate; therapeutically, reorient regularly, short/simple instructions, frequent rest breaks, write down answers to frequently asked questions, reminisce on fun past experiences/family
Level VI= confused, appropriate, can follow a schedule w/assist, oriented to date/year, pays attention in non-distracting environment, aware of physical problems more so than cognitive/safety issues; reorient, repeat directions, encourage ownership of ADLs/therapy, use written material/references
Level VII = automatic, appropriate responses (follow what people tell them to do, almost robotic, but non planning/purposeful, not super flexible)
Level VIII = purposeful, appropriate response
(have also added a level IX and X! But I - VIII are most common)
Level IX = purposeful appropriate (standby assist on request)
Level X = purposeful appropriate (modified independent)
How do we classify “disorders of Consciousness” on the RLA scale? What are the 4 “stages” of DOC?
DOC = RLA levels I-III DOC ranges from: Brain Death = no brain activity Coma = eyes closed, no response Vegetative state = signs of response Minimally Conscious State = signs of purposeful response
A coma is a state of unarousable responsiveness in which they eyes [are open/ stay continuously closed].
- Response to stim?
- Sleep/wake cycles?
- Type of motor activity we see?
- What aspect of the brain injury causes this?
Generally, coma is [permanent / temporary, individual will progress to either vegetative of minimally conscious state].
Emergence from a coma in ____-___ wks predicts a more favorable outcome
A coma is a state of unarousable responsiveness in which they eyes stay CONTINUOUSLY CLOSED. NO understandable response to stimuli. NO sleep/wake cycles. REFLEXIVE activity only.
What aspect of brain injury causes coma?
- Most likely caused by the DAI in brainstem, midbrain
- May also be extensive B FRONTAL WHITE MATTER involvement
- Swelling -> herniation
- Medullary lesions may also cause coma, but short duration
Generally this is temporary! Individual will progress to either vegetative of minimally conscious state. Emergence from a coma in 2-4 wks predicts a more favorable outcome
A vegetative state is also known as “unresponsive wakefulness.” This individual has no signs of conscious awareness of [self / environment / both].
- Eyes are [open / closed]
- Reflexes?
- Sleep/wake cycles?
- Command following?
- Autonomic functions are [intact /disrupted]
Starting to have sleep wake cycles but NOT following commands. Autonomic system is intact for basic functions.
“Persistent” vegetative state = ___ [amt of time], vs “permanent” vegetative state = [amt of time.]
A vegetative state is also known as “unresponsive wakefulness.” This individual has no signs of conscious awareness of SELF OR ENVIRONMENT.
- Eyes are OPEN
- Reflexes INTACT
- Sleep/wake cycles are PRESENT (or at least emerging)
- NO command following
- Autonomic functions are INTACT for basic functions.
“Persistent” vegetative state = 1 MONTH
“Permanent” vegetative state = 12 MONTHS. Likelihood of emerging from this at this stage is slim.
A minimally conscious state is a condition of severely altered consciousness in which minimal, but definite behavioral evidence of self or environmental awareness is demonstrated. Inconsistent responses, but may include following commands, verbalization, yes/no responses, movement in response to environment (not reflexive)
In MCS, half of these patients have ___ lesions and 42% have grade [I / II / III] DAI. More sparing of cortical connections compared to those in a coma or vegetative state.
A minimally conscious state is a condition of severely altered consciousness in which minimal, but definite behavioral evidence of self or environmental awareness is demonstrated. Inconsistent responses, but may include following commands, verbalization, yes/no responses, movement in response to environment (not reflexive)
In MCS, half of these patients have thalamic lesions and 42% have grade II DAI. More sparing of cortical connections compared to those in a coma or vegetative state.
Prognostic indicators post brain injury…
Younger age/gender (women tend to do better than men)
GCS
Length of post traumatic amnesia (how long it takes for them to start establishing new injuries)
Traumatic injuries tend to do better than vascular/anoxic (because traumatic tends to be more focal)
Higher education level/pre-injury IQ
Early use of neurostimulants (e.g. ritalin)
Presence of pre-injury psych issues or substance abuse
Coma Recovery Scale - Revised (CRS-R):
23 items on __ subscales - what are they? It takes ~25 mins.
What do we use it for?
6 subscales, higher score is better: Auditory, visual, motor function, Oral motor, communication, and arousal
Used to detail which areas are still difficult for pt, used for prognosticating and treatment planning. Can indicate emergence from vegetative -> minimally conscious state -> emerging from minimally conscious state
When to use the DOCs scale vs CRS-R? How long does each take?
CRS-R is a little broader, takes ~25 mins, no training required - give a good 20-30 sec to get the desired response! Takes a bit!
DOCs scale is used in TBI to detect more subtle changes in observable indicators of neurobehavioral functioning. Requires training, takes ~45 mins
Emergence from a minimally conscious state is marked by the return of reliable and consistent interactive __ or ____.
Emergence from a minimally conscious state is marked by the return of reliable and consistent interactive COMMUNICATION or FUNCTIONAL OBJECT USE.
Meds to help with arousal = ___. Examples?
Stimulants help w/arousal. Examples include:
Amantadine
Ritalin
Provigil
