6 - Head Trauma

Question 1

When suturing the scalp, ensure what layer is closed?

Answer 1

The gelea layer

Question 2

Acronym for SCALP from the outside in:

Answer 2

Skin

Connective tissue

galea Aponeurosa

Loose areolar tissue

Pericranium

Question 3

Signs of basilar skull fx:

Answer 3

Periorbital ecchymosis

Battle’s sign (post-auricular ecchymosis - at the mastoid process)

CSF from nose/ear

Question 4

Normal txt for simple/linear skull fx:

Answer 4

Normally do not require surgery

Question 5

Open or depressed skull fx txt:

Answer 5

These will need surgery

Question 6

Preferred imaging for head trauma?

Answer 6

CT

Can be difficult to see on x-ray

Question 7

What is primary brain injury?

Answer 7

Damage to the brain parenchyma of blood vessels

Not much you can do txt this in the field

Ischemia, hematoma, anoxia/hypoxia, shear injury

Question 8

Secondary brain injury is:

Answer 8

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

Question 9

Primary survery

Answer 9

X - exsanguination 
A - airway
B - breathing
C - circulation
D - disability (identify neuro deficit)
E - undress, evaluate, prevent hypothermia

Question 10

What breathing-related complication occurs in 40% of TBI’s?

Answer 10

Hypoxia

So we assess ventilations q 5 mins and PRN

Question 11

Signs of hypoxia

Answer 11

Impaired judgement, confusion, delirium, agitation

Coma

Peripheral vasoconstriction

Tachycardia

Tachypnea

Question 12

What could cause a false SpO2 reading

Answer 12

Cold temps

Poor peripheral perfusion

CO poisoning

Question 13

Goal is to maintain SBP above:

Answer 13

90mmHg

A single episode of HOTN can lead to disastrous outcomes

Question 14

What is a quick way to ensure you’ve got an SBP above 90mmHg?

Answer 14

If they’ve got a palpable radial pulse

Question 15

How to calculate MAP:

Answer 15

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”

Question 16

Cerebral Perfusion Pressure (CPP) calculation:

Answer 16

MAP - ICP

You’re given ICP via ventriculostomy (placed by neurosurgery)

He said “this one i’ll have you do on the exam”

Question 17

ICP monitor (Bolt) is placed by neurosurgery and may be placed:

Answer 17

Epidural space

Subdural space

Intra-parenchymal

Intraventricular

Question 18

GCS reminder

Answer 18

Slide 16

14-15 ok
9-13 moderate
3-8 severe

Question 19

Check pupils

Answer 19

Symmetry - within 1mm of eachother

Reaction of less than 1mm to light = bad

Normal size in adults = 4mm

Question 20

What is hypema?

Answer 20

Blood pooling in the anterior chamber

Can be a sign of TBI

Question 21

Non-traumatic causes of abnormally dilated pupils?

Answer 21

Hypoxia
Hypothermia
Hypotension
Orbital trauma
Atropine
Epinephrine
Cocaine
Amphetamines

Question 22

Non-traumatic causes of constricted pupils:

Answer 22

Narcotics

Organophosphates

Question 23

What will cerebral edema look like on CT?

Answer 23

Loss of grey-white differentiation

Question 24

Midline shift suggests:

Answer 24

Herniation of brainstem

Pupil changes on ipsilateral side of herniation

Txt the elevated ICP - elevate the head of the bed, maintain ventilation

Question 25

CT presentation of different brain bleeds:

Answer 25

Quick and dirty: Subdural - longer and thinner (crescent?) Epidural - fatter, looks more like a bulge Intracerebral - spotty

Question 26

Cushing’s Triad:

Answer 26

1. Increased SBP (or widened pulse pressure) 2. Bradycardia 3. 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

Question 27

Hyperventilation as txt is tricky, here’s why:

Answer 27

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

Question 28

Colorimetric capnography:

Answer 28

Yellow - exhaling CO2 | Purple - inhaling O2

Question 29

What is diffuse axonal injury:

Answer 29

Traumatic shearing with rapid acceleration / deceleration MVC’s, falls, assaults Twisting or rotational forces Coup/countercoup Sports injury Child abuse CT APPEARS NORMAL

Question 30

Management of TBI:

Answer 30

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)

Question 31

If TBI patient is agitated:

Answer 31

RSI (GCS <8) Propofol + Fentanyl Propofol -> better outcomes than benzos and narcs - higher CPP and lower ICP

Question 32

Seizure prophylaxis for TBI’s

Answer 32

Keppra x 1 week

Question 33

Target H and H for the TBI patient:

Answer 33

Hgb: 7-10 Hct: 21-30

Question 34

Electrolyte considerations for TBI

Answer 34

High incidence of hyponatremia 2/2 SIADH and cerebral salt wasting Monitor closely and try to keep eunatremic

Question 35

Neurosurgical interventions

Answer 35

Ventriculostomy CSF drain Decompressive craniectomy Barbituate metabolic coma *goal of all of these is to maintain ICP < 20mmHg

Question 36

Last night i dreamed i was a muffler

Answer 36

I woke up exhausted