Traumatic Brain Injury Flashcards
Traumatic Brain Injury TBI - Definition
Brain injuries resulting from a blunt blow to the head, rapid deceleration, or penetration by a missile or sharp object
Goal of Care
Rapid transport while minimizing secondary injury
Overview -
Brain injury can range from minor to major w/ permanent neurological injury or death
Brain Injury includes both primary and secondary components:
Primary Injury
Primary injury - is the area that is destroyed at the time of the injury and will never
recover
Areas around the primary injury, similar to areas around an ischemic stroke (the penumbra) are compromised but may recover if given optimum care beginning in the field
Injured cells have the best change of recover if normal blood pressure, adequat oxygenation and normal CO2 levels are maintained at all times.
Even a brief episode of unnecessary hypotension, hypertension, hypoxia or abnormal CO2 can result in preventable and permanent neurologic impairment or death
Secondary Injury
Secondary bleeding inside the closed cranium (subdural or epidural) can steadily increase pressure on the brain and result in further disability or death unrelated to the direct impact.
Emergent surgical decompression is required
Special Note 1
All pts w/ head trauma and any altered LOC (witnessed or by hx) should be suspected of having a tarumatic brain inj and be transported w/o delay
Assume a spinal injury and stabilize the spine during transport, minimizing time ons as much as possible
Guiding Principles
The most important goals in pre-hospital treatment of head inj are rapid transport while minimizing secondary injury. This can be very challenging.
The preferred destination will be a facility w/ neurosurgical capability
Follow trauma destination decision rules for your area
Other injuries are common w/ brain injury and will be less apparent
Preventing secondary injury is acomplished by
- Ensuring adequate oxygenation (SpO2 >95)
- Maintaining a blood pressure adequate to perfuse cerebral circulation (MAP >80 or SBP >120)
- Maintaining normal blood glucose levels 4.0-8.0 (a BGL is mandatory for all head inj’d pts w/ a DLOC)
Special Note 2
A patent airway is essential. Supp O2 <95
Often it is best to ensure a patent airway and oxygenation and let the pt determine the respiratory volume and rate
Guiding Principles - Vents
Assisted vents are only req’d if you cannot maintain oxygenation or the pt clearly exhibits an inadequate volume or rate
For ACP, ET intubation may be necessary to maintain airway patency or ventilation. the decision to intubate must be carefully considered
Special Note 3
A low GCS by itself is not a reason to intubate.
Risks associated w/ intubation include’ delay in surgical intervention; hypoxia during the attempt; hypercapnia during the attempt; hypocapia after successful intubation; hypertension secondary to the airway reflex; and induction agent induced hypotension and loss of sympathetic drive.
Each of these is possible even in a seemingly uneventful insertion of the ET tube, and likely worsens neurologic outcome
Monitor O2 saturation before during and after intubation and ETCO2 as soon as possible
Guiding Principles - Hypotension
The concept of permissive hypotension in trauma does NOT apply in head injs w/ reduced LOC
Hypotension should be treated w/ a normal saline fluid challenge during transport
A systolic BP >120 is appropriate to ensure adequate cerebral perfusion
Once that level is reached, fluids can be slowed to keep the vein open
Fluid overload results in secondary increased intracranial pressure which increases secondary inj
Intervention Guideline - EMR
EMR Assess wakefulness and perfusion Basic airway management Supp O2 if sats <95% IPPV if required Control life threatening bleeding Control ongoing hemorrhage Facilitate transport Elevate the head 30 degrees Loosen cervical collar Early hospital notification BGL check
Intervention Guideline - PCP
Correct hypoperfusion/hypovolemia to achieve BP >120
- IV therapy 2 large bore IV enroute
- Fluid bolus NS up to 2L
- Reassess every 500ml
- Target SPB >120
Intervention Guideline - ACP
NG/OG tube
Intubation as per Adult Induction Duidelines
Sedation and Analgesia
Midazolam - 2mg IV to effect - max 10mg
Morphine - 2.5-5mg IV every 15 mins to effect
Further Care
Early Transport to Tertiary Care
1) Advanced Care or Critical Care transport (air or ground)
2) Neurocritical care centre of excellence
Maintain cerebral perfusion
1) Crystalloid (e.g. normal saline, blood products)
2) Vasoactive medications (e.g. norepinephrine, vasopressin)
Reduce ICP
1) Sedation (e.g. Propofol, Ketamine)
2) Analgesic (e.g Fentanyl)
3) Paralytics (e.g. Rocuronium)
4) Hyperosmolar therapy (e.g. hypertonic saline or mannitol)
5) Neurosurgical intervention (e.g. drains, advanced pressure monitors, craniotomy)
Prevent Secondary Injury
1) Monitor laboratory and imagining studies
2) Seizure prophylaxis (e.g. phenytoin)
Other Important Considerations
1) Rehabilitation
