Moderate And Severe Traumatic Brain Injury Flashcards
Lifetime cost of severe TBI per person
4 million
Annual cost of TBI
80 billion
Common causes of TBI
- MVC 20%
- Falls 28%
- Violence 11%
- Sport/recreation 10%
Closed head injury
External forces/objects hitting the head or hitting head hard enough to cause brain movement
- May see coup/contrecoup injury
Severe acceleration/deceleration
May cause injury without head strike
- Whiplash, shaken-baby syndrome
Blast injuries
Explosions resulting in fast moving pressure wave affecting skull and brain parenchyma
Penetrating injuries
Objects breaching skull cavity cause direct cellular and vascular damage
Contre-coup lesions
Results from a closed head injury when the skull comes to a stop then brain rebounds
Primary damage resulting from TBI
- Contusions
- Lacerations
- Epidural hematoma/hemorrhage
- Subdural hematoma
- Diffuse axonal injury
- Penetrating injuries
- Blast injuries
Brain contusions
Bruise within the brain, can occur in any region
Lacerations in the brain
Can occur in areas where the skull surface is irregular or to brain vasculature
- Can cause CSF leak if dura compromised
Epidural hematoma/hemorrhage in TBI
Tearing of meningeal vessels causes blood to collect between skull and dura, highly associated with skull fracture
Subdural hematoma
Result of tears to bridging veins, often due to acceleration/deceleration injury including falls
Diffuse axonal injury
Aka shearing injury, very common even in mild TBI
- Brain tissues that differ in structure/weight respond differently to acceleration/deceleration/rotation during trauma -> compromise to cellular membranes
Penetrating injuries
- Direct damage to tissues contacted
- High velocity objects ie. Bullets cause additional damage to remote areas of brain due to shock waves
Blast injuries
High pressure wave (overpressure) followed by low pressure wave (underpressure) -> compression/shearing of tissue, diffuse injury
Secondary damage following TBI
- Increased intracranial pressure
- Cerebral ischemia or hypoxia
- Electrolyte imbalance and acid/base balance
- Infection
- Seizures
Increased intracranial pressure following TBI
- Due to swelling or hematoma
- Skull cavity is fixed, increasing pressure can lead to tissue distortion ie. Midline shift or herniation
- Normal: 5-20 cm H2O
Cerebral ischemia or hypoxia following TBI
Results from compressed or ruptured vessels
Electrolyte imbalance and acid/base balance following TBI
Biochemical effects of neuron injury leading to cell death by necrosis or apoptosis
Infection following TBI
Can occur from open wounds or invasive monitoring
Seizures following TBI
Can occur due to tissue damage, pressure or scarring
Extra-ventricular drain
Catheter fed into lateral ventricle to monitor ICP and drain excess CSF
Autonomic nervous system and TBI
- Elevated sympathetic nervous system activity occurs following injury and can become sustained resulting in
- Increased HR/RR
- Increased BP
- Diaphoresis
- Excessive salivation, tearing
- Hyperthermia
- Dilated pupils
- Vomiting
Motor, functional, sensory, and perceptual changes following TBI
- Paralysis or paresis
- Cranial nerve injury
- Poor coordination
- Abnormal reflexes
- Abnormal tone
- Loss of selective motor control
- Poor balance
- Loss of bowel or bladder control
- Hypersensitivity to light or noise
- Loss of hearing or sight
- Visual field changes
- Numbness tingling
- Dizziness or vertigo
- Agnosia
- Apraxia
Decorticate posture
Lesion occurs above the red nucleus
- Flexors predominate upper limbs
Decerebrate posture
Lesion occurs blow the red nucleus
- Extensors predominate upper and lower limbs
Coma
Complete paralysis of cerebral function or a state of unresponsiveness
- Eyes closed, no response to painful stimuli, no obvious sleep/wake cycles, usually ventilator dependent, no pupil rxn to light (absent brainstem responses)
Unresponsive wakefulness
Wakeful, reduced responsiveness with no evident cerebral cortical function
- Intermittent periods of wakefulness
- Brainstem usually mostly intact
- Previously referred to as a vegetative state
Minimally conscious state
Clear but minimal or inconsistent awareness
- Can demonstrate motor responses reproducibly and respond to one step commands (even if inconsistently)
- Sleeps a lot, exhibits reduced alertness, disinterest in the environment, slow responses to stimulation
Post-traumatic amnesia
The time lapse between the injury and when memory functions are restored
Retrograde amnesia
Deficit in memory retrieval with inability to recall events that occurred prior to the injury
Anterograde amnesia
Inability to form new memories after the injury
Impaired working memory
A type of short-term memory eg. Ability to remember steps of a recipe while cooking
Neurobehavioral changes following TBI
- Low frustration tolerance
- Agitation and irritability
- Disinhibition
- Apathy
- Emotional lability
- Mental inflexibility
- Aggression
- Impulsivity
Secondary complication following hospital stay (typically) for TBI pts
- Latrogenic injuries: catheters, NG tubes, tracheotomies (speech/swallowing function)
- Infections: UTI, pneumonia
- Prolonged bed rest: contractures, skin breakdown, heterotrophic ossification (development of bone at myotendinous junction), DVT
- Surgical complications
- Post-traumatic epilepsy
- Depression: reactive or d/t damage to brain
Glasgow coma scale
- Eye opening: spontaneous (4) to speech (3) to pain (2) nil (1)
- Best most response: obeys (6) localizes (5) withdrawals (4) abnormal flexion (3) extensor response (2) nil (1)
- Verbal response: oriented (5) confused conversation (4) inappropriate words (3) incomprehensible sounds (2) nil (1)
Score: E + M + V = 3-15
Mild TBI GCS
- Glasgow coma scale: 13-15
- LOS <30 min
- PTA 0-1 day
Moderate TBI GCS
- Glasgow coma scale: 9-12
- LOC 30 min - 24 hours
- PTA >1 day to </= 7 days
Severe TBI GCS
- Glasgow coma scale: 3-8
- LOC >24 hours
- PTA >7 days
Ranches los amigos levels of cognitive functioning scale
- Used to classify levels of TBI (8) measures, consciousness, cognition, and behaviors
- Often used to track progress through various stages of medical care and rehab
1. No response to visual, verbal, tactile, auditory, or noxious stimuli
2. Generalized response
3. Localized response
4. Confused and agitated
5. Confused and inappropriate
6. Confused and appropriate
7. Automatic and appropriate
8. Purposeful and appropriate
- No response
Patient appears to be in a deep sleep and is completely unresponsive to any stimuli (most similar to coma)
- Generalized response
Patient reacts inconsistently and nonpurposefully to stimuli in a nonspecific manner. Responses are limited and often the same regardless of stimulus present. Responses may by physiologic changes, gross body movements, and/or vocalization
- Most similar to unresponsive wakefulness
- Confused-agitated
Patient is in a heightened state of activity. Behavior is bizarre and nonpurposeful relative to immediate environment. Does no discriminate among persons or objects, is unable to cooperate directly with treatment efforts. Verbalizations frequently are incoherent and/or inappropriate to the environment, confabulation may be present. Gross attention environment if very brief, selective attention is often nonexistent. Patient lacks short and long term recall
- Localized response
Patient reacts specifically but inconsistently to stimuli. Responses are directly related to the type of stimulus presented. May follow simple commands such as closing eyes or squeezing hand in an inconsistent, delayed manner
- Most similar to minimally conscious state
- Confused in-appropriate
Patient is able to respond to simple commands fairly consistently. However, with increased complexity of commands or lack of any external structure, responses are nonpurposeful, random, or fragmented. Demonstrates gross attention to the environment but is highly distractible and lacks ability to focus attention on specific task. With structure, may be able to converse on a social automatic level for short periods of time. Verbalization is often inappropriate and confabulatory. Memory is severely impaired; often shows inappropriate use of objects may perform previously learned tasks with structure but is unable to learn new information
- Confused appropriate
Patient shows goal-directed behavior but is dependent on external input or direction. Follows simple directions consistently and shows carryover for relearned tasks such as self-care. Responses mat be incorrect due to memory problems, but they are appropriate to the situation. Past memories show more depth and detail than recent memory
- Automatic appropriate
Patient appears appropriate and oriented within the hospital and home settings; goes through daily routine automatically, but frequently robot-like. Patient shows minimal to no confusion and has shallow recall of activities. Shows carryover for new learning but at a decreased rate. With structure is able to initiate social or recreational activities, judgment remains impaired
- Purposeful appropriate
Patient is able to recall and integrate past and recent events and is aware of and responsive to environment. Shows carryover for new learning and needs no supervision once activities are learned. May continue to show a decreased ability relative to premorbid abilities, abstract reasoning, tolerance for stress, and judgment in emergencies or unusual circumstances
Pre-hospital phase (at the scene) care following TBI
Monitor for oxygenation, BP, overall function (using GCS), pupillary function, and other signs of brainstem herniation
Emergency department management following TBI
- Determine GCS score if not already done
- Airway control and ventilation -> oxygenation
- Monitoring/maintenance of cerebral perfusion pressure and BP
- Monitoring and management of ICP
- Fluid management
- Hyperosmolar therapy (using fluids of diff. Ionic concentrations to reduce cerebral edema and ICP)
- Sedation
- Prophylaxis of infection, DVT, seizure
Decompressive craniectomy
Large portion of skull removed to allow the brain to swell
Prognostic indicators
- Age: older age -> poorer outcomes and increased risk of mortality
- Clinical severity: lower GCS scores -> poorer outcomes and increased risk of mortality
- Initial CT scan: presence of subarachnoid hemorrhage (deeper brain bleed)
- Secondary insults: hypoxia, hypotension (poorly effects cerebral brain tissue)
- Lab values: high glucose concentrations, coagulopathy
- Duration of coma and PTA: longer -> poorer outcomes
Systems review following TBI
- More complex
- Circulatory/respiratory: decreased cardiovascular endurance/fitness, decreased chest mobility and expansion, pulmonary congestion, thrombophlebitis, concomitant injuries
- Integumentary: pressure sores, concomitant injuries (abrasions, lacerations)
- MSK: muscle contractures/tightness, altered joint mobility/stability, disuse atrophy/weakness, decreased muscular endurance, concomitant injuries (hip precautions?)
- Nervous: motor performance/sensory/perceptual disturbances, behavioral changes, cognitive disabilities, concomitant injuries (peripheral nerve injury, spinal cord injuries)
Inpatient rehab facility’s patient assessment instrument
- Outcome measure of functional abilities and goals scored by use of codes that range from 01 (dependent) to 06 (independent)
- Includes bed mobility, transfers, toileting, car, walking
Consciousness outcome measures
- Coma recovery scale: assist with DDx, prognosis, and tx planning in pts, 23 items, 6 sub scales
- Level of conscious functional scale
Cognition outcome measure used in TBI pts
Montreal cognitive assessment (MoCA)
