TBI Pathophysiology Flashcards
What is a TBI?
A brain injury caused by a hit to the head that ranges from mild to severe depending on the amount of change to mental status and the length of time a patient is unconscious
What are the most common causes of a TBI?
Falls (48%)
Unintentionally struck (17%)
MVAs (13%)
What are some ways you classify a TBI?
- Chronicity of Injury (acute vs. chronic)
- Mechanism of Injury
- Severity of Injury (mild to severe)
- Level of Cognition Currently (Rancho Scale of Cognitive Function)
- Level of Arousal at Time of Injury (Glasgow Coma Scale)
What type of head Injury occurs from Direct Contact?
- Concussion
- Contusion (coup/counter-coup)
- Hematoma (epidural intracerebral or subarachnoid)
What type of head Injury occurs from a Penetrating Injury?
What type of head Injury occurs from a Blast Injury?
What type of head Injury occurs from a Heart attack or near drowning?
Invasive injury to neuronal and vasculature tissue
Diffuse Axonal Injury
- Anoxia
- Hypoxia
What type of head Injury occurs from an Acceleration/Deceleration Injury?
- Concussion
- Hematoma (subdural)
- Diffuse Axonal Injury
What is a head contusion?
How are they identified?
How are they differentiated from a hematoma?
Swollen brain tissue where there is vascular and tissue damage which can be a response to the brain moving within the skull
Identified by a CT scan and appears as a hemorrhagic lesion
differentiated from hematoma in that blood is intermixed w/ brain tissue
What is a cranial hematoma?
What are the 3 different types?
Damage to major blood vessels in the head or heavy bleeding into or around the brain
Epidural (bleeding between skull and dura)
Subdural (bleeding between dura and arachnoid)
Subarachnoid, Intracerebral (bleeding within brain)
What is a diffuse axonal injury?
Are they identified on CT scans?
torsion or shearing of long axons
However not every axonal injury is a diffuse injury, diffuse injuries interrupt axonal transport and have axonal swelling
Not identified on CT and sometimes not on MRI’s either
What is a primary blast injury?
Occurs following high order over-pressurizing shock wave moving through the body, affects gas-filled organs such as the lungs, GI tract, and middle ear
What is a secondary blast injury?
caused by bomb fragments and other objects propelled by the explosion resulting in penetrating injuries
What is a tertiary blast injury?
Results from the blast wind throwing the victim and include bone fractures and amputation
What is a quaternary blast injury?
includes injuries not included in first three levels such as burns, crush injuries and respiratory injuries
What is normal intracranial pressure (ICP) and what would be considered excessive ICP?
What can excessive ICP cause?
What are signs of excessive ICP?
typical ICP=10-15 mm Hg in supine and -10 in standing
excessive ICP= over 20-25 mm Hg and can cause papilledema, herniation, brain tissue damage, stroke, etc.
signs include decreased pulse rate, change in conciousness, agitation, and coma
What is Cushing’s Triad?
What would the opposite of the triad indicate?
Three primary signs that often indicate increased ICP
they include:
increase systolic BP
Decreased pulse and respiration
These signs are the exact opposite for Shock
