6 - Head Trauma Flashcards
When suturing the scalp, ensure what layer is closed?
The gelea layer
Acronym for SCALP from the outside in:
Skin
Connective tissue
galea Aponeurosa
Loose areolar tissue
Pericranium
Signs of basilar skull fx:
Periorbital ecchymosis
Battle’s sign (post-auricular ecchymosis - at the mastoid process)
CSF from nose/ear
Normal txt for simple/linear skull fx:
Normally do not require surgery
Open or depressed skull fx txt:
These will need surgery
Preferred imaging for head trauma?
CT
Can be difficult to see on x-ray
What is primary brain injury?
Damage to the brain parenchyma of blood vessels
Not much you can do txt this in the field
Ischemia, hematoma, anoxia/hypoxia, shear injury
Secondary brain injury is:
The sequelae of the primary brain injury
In the field you can actually do stuff to reduce likelihood of secondary brain injury
Hypoxia, HOTN -> decreased cerebral flow, increased ICP, hyper- or hypoglycemia, seizures
Primary survery
X - exsanguination A - airway B - breathing C - circulation D - disability (identify neuro deficit) E - undress, evaluate, prevent hypothermia
What breathing-related complication occurs in 40% of TBI’s?
Hypoxia
So we assess ventilations q 5 mins and PRN
Signs of hypoxia
Impaired judgement, confusion, delirium, agitation
Coma
Peripheral vasoconstriction
Tachycardia
Tachypnea
What could cause a false SpO2 reading
Cold temps
Poor peripheral perfusion
CO poisoning
Goal is to maintain SBP above:
90mmHg
A single episode of HOTN can lead to disastrous outcomes
What is a quick way to ensure you’ve got an SBP above 90mmHg?
If they’ve got a palpable radial pulse
How to calculate MAP:
1/3 (SBP + 2DBP)
i.e. if BP is 90/60, MAP = 1/3 (90 + 120) = 70
He said “won’t make you calculate MAP”
Cerebral Perfusion Pressure (CPP) calculation:
MAP - ICP
You’re given ICP via ventriculostomy (placed by neurosurgery)
He said “this one i’ll have you do on the exam”
ICP monitor (Bolt) is placed by neurosurgery and may be placed:
Epidural space
Subdural space
Intra-parenchymal
Intraventricular
GCS reminder
Slide 16
14-15 ok
9-13 moderate
3-8 severe
Check pupils
Symmetry - within 1mm of eachother
Reaction of less than 1mm to light = bad
Normal size in adults = 4mm
What is hypema?
Blood pooling in the anterior chamber
Can be a sign of TBI
Non-traumatic causes of abnormally dilated pupils?
Hypoxia Hypothermia Hypotension Orbital trauma Atropine Epinephrine Cocaine Amphetamines
Non-traumatic causes of constricted pupils:
Narcotics
Organophosphates
What will cerebral edema look like on CT?
Loss of grey-white differentiation
Midline shift suggests:
Herniation of brainstem
Pupil changes on ipsilateral side of herniation
Txt the elevated ICP - elevate the head of the bed, maintain ventilation
CT presentation of different brain bleeds:
Quick and dirty:
Subdural - longer and thinner (crescent?)
Epidural - fatter, looks more like a bulge
Intracerebral - spotty
Cushing’s Triad:
- Increased SBP (or widened pulse pressure)
- Bradycardia
- Irregular respirations
Classic presentation for brainstem herniation
GCS 3-5
Dilated and unresponsive pupils and lateral gaze -> brainstem herniation through tentorium cerebelli and compression of CN III
Hyperventilation as txt is tricky, here’s why:
For brainstem herniation
Hyperventilation produces rapid decrease in pCO2 -> vasoconstriction which lowers ICP -> this gives more room for the brain to swell
HOWEVER -> this tactic also cause a decrease in CPP to the point of ischemia
So, gotta find that sweet spot - aim for pCO2 between 35-45mmHg during normal respiration and between 25-35mmHg during hyperventilation
Colorimetric capnography:
Yellow - exhaling CO2
Purple - inhaling O2
What is diffuse axonal injury:
Traumatic shearing with rapid acceleration / deceleration
MVC’s, falls, assaults
Twisting or rotational forces
Coup/countercoup
Sports injury
Child abuse
CT APPEARS NORMAL
Management of TBI:
Manage shock aggressively
Keep SBP > 90 (this keeps MAP > 70 and ICP < 20)
Hypertonic saline gets us maximum intravascular expansion with minimal volume
Hetastarch -> large sugar molecule, similar to albumin (colloid) creates osmotic gradient
Mannitol - reduces ICP
Keep sugar above 80mg/dL (bolus D50 if needed)
If TBI patient is agitated:
RSI (GCS <8)
Propofol + Fentanyl
Propofol -> better outcomes than benzos and narcs - higher CPP and lower ICP
Seizure prophylaxis for TBI’s
Keppra x 1 week
Target H and H for the TBI patient:
Hgb: 7-10
Hct: 21-30
Electrolyte considerations for TBI
High incidence of hyponatremia 2/2 SIADH and cerebral salt wasting
Monitor closely and try to keep eunatremic
Neurosurgical interventions
Ventriculostomy
CSF drain
Decompressive craniectomy
Barbituate metabolic coma
*goal of all of these is to maintain ICP < 20mmHg
Last night i dreamed i was a muffler
I woke up exhausted
