24 Head Trauma - Terms/definitions/less Impt

Front 1

1) Trauma is the leading cause of death for children aged what?

2) Trauma makes up what % of fatal pediatric injuries?

Back 1

1) 1 to 14

2) 40%

Front 2

1) What's the incidence rate of trauma injuries?
2) Mortality rate?
3) Gender bias?

Back 2

1) 200/1000

2) 10%

3) M:F = 2:1

Front 3

Are trauma injuries high in a particular season?

Back 3

Yes, in summer

Front 4

Annually, trauma accounts for:
1) how many pediatric hospitalizations?
2) how many ER visits?
3) how many permanent disabilities?
4) how many deaths?
5) how much $$ in hospital care?

Back 4

1) 100,000
2) 500,000
3) 29,000
4) 7,000
5) > $1 billion

Front 5

What is the Glascow Coma Scale?

Back 5

Most common measure used to gauge head trauma that contains three scores (motor, verbal, and eye opening)

Front 6

Why is the Glascow Coma Scale particular useful?

Back 6

1) It's standardized so any doctor can do it

2) along with age, it can help determine prognosis in head injury
--> a worse initial GSC is associated with a worse outcome

Front 7

On what scale is the Glascow Coma Scale measured?

Back 7

On a scale of 3 to 15 (worse possible core being a 3 -- no eye opening, verbal response, or motor activity)

Front 8

What are the 3 different categories of head injuries given by the Glascow Coma Scale?

Back 8

1) Mild (13-15)
2) Moderate (9-12)
3) Severe (<8)

Front 9

What category classified someone as "not being able to take care of themselves, needing intubation and sedation"?

Back 9

Severe

Front 10

What can alter the Glascow Coma Scale?

Back 10

sedatives, paralytics, other drugs

Front 11

What's the primary and secondary head trauma?

Back 11

Primary - the immediate energy dissipation/injury to the brain

Secondary - the biochemical cascade (things that doctors try to prevent at the hospital like hypoxia, low blood flow)

Front 12

What are the different ways to classify head trauma based on the actual injury to the head?

Back 12

~Closed Head Trauma~
*Concussion – alteration of consciousness as a result of closed head injury

*Contusion – low density on CT representing edema or injury to brain (hemorrhagic)

*Contrecoup – “counter blow” injury directly opposite to the blow

*Diffuse axonal injury – rotational deceleration results in shear injury to axons in brain

Front 13

What are the different ways to classify head trauma based on the mechanism of injury to the head?

Back 13

~Mechanism~
*Penetrating (Missile/gun-shot or Non-missile/stab injuries)
*Closed Head Injury (High velocity or Low velocity)

Front 14

What's the mainstay for physically assessing head trauma?

Why are children special with regards to CT scans?

Back 14

1) CT scans - quick/rapid; best for evaluation of fractures, acute

2) radiation exposure is a particular concern, so children often get a "rapid CT" scan -- looks for edema, hemorrhage, and requires no sedation

Front 15

How is head trauma classified based on morphology/pathology?
(don't memorize all of these, just keep in mind that there is variance)

Back 15

*Skull fractures
--> linear
--> depressed
--> complex & comminuted
--> compound -Basilar, Frontal sinus)

*Intracranial lesions
--> focal: extradural, subdural, intraprenchymal hematomas, contusion, foreign body, subarachnoid, intraventricular hemorrhage
--> diffuse: concussion, DAI

Front 16

Are primary injuries reversible?

Back 16

No -- there are only prevention strategies

Front 17

When does secondary injury occur?

What is therapy for secondary injuries directed at?

Back 17

Minutes to days after the primary injury

*limiting further cell death

Front 18

What are characteristics of primary direct injuries?

Back 18

~Direct injury~
*impact by object or compression
*external signs of trauma
*skull fracture if force sufficient
transmitted force to brain tissue
*injury pattern --> skull fracture, epidural, contusion
*associated indirect injury

Front 19

What are characteristics of primary indirect injuries?

Back 19

*cranial contents set into vigorous motion -->acceleration/deceleration, rotational, angular forces
*bridging subdural vessel strain
*differential acceleration – shear injuries
*impact of brain on inner aspect of skull
*injury pattern – subdural, DAI, concussion, contracoup injury

Front 20

What are the mechanisms of secondary injuries?

Back 20

*systemic insults
*intracranial lesions
*neuroendocrine disturbance
*membrane failure
*abnormal ion fluxes
*edema

Front 21

What's the goal of secondary injury intervention?

Back 21

To limit further brain cell damage

Front 22

What is the Monroe-Kellie hypothesis and is it about?

Back 22

-->management of ICP because the amount of brain + blood + CSF stays constant unless disturbed:
-The skull is completely closed and inelastic and is therefore a fixed compartment

-The sum of the intracranial volumes of blood, brain, and CSF is constant and an increase in any one must be offset by an equal decrease in another or else pressure will rise.

Front 23

What are the different ways to manage ICP?

Back 23

*Surgical evacuation
*ICP monitor
*External Ventricular Drain
*Hyperventilation
*Osmotic agents – Mannitol vs *Hypertonic saline
*Paralysis
*Seizure prophylaxis
*Decompressive craniectomy (if all else fails)

Front 24

If a brain doesn't have any sort of mass or lesion but ICP is increasing, what is the technique called to remove excess CSF?

Back 24

External Ventricular Drain (EVD) aka Ventriculostomy

Front 25

When are Camino Intracranial Monitors (Bolt) used?

Back 25

Commonly in setting of cerebral edema to manage ICP when ventricles may be too small to safely access via EVD

Front 26

How does hyperventilation work as an ICP management technique?

Back 26

hypocapnea --> vasoconstrict --> decreased CBF --> decreased ICP
*goal pCO2 25-35
*onset: 30 seconds
*peak: 8 minutes
*Tachyphylaxis
**Effective in reducing ICP, but it reduces CBF in the end (reduces O2)**

Front 27

When is hyperventilation used to manage ICP?

Back 27

*Used for acute increase in ICP, NOT for prophylaxis

Front 28

How is mannitol used to manage ICP? Any problems with using this?

Back 28

It's a diuretic agent
*works via the osmotic gradient – prevents edema formation, reduces ICP
*mannitol is a volume EXPANDER
*Problems --> hypovolemia, repeated doses/infusions will open BBB and it accumulates

Front 29

What's now used more often than mannitol? What's its mechanism?

Back 29

*Hypertonic saline*
Also a diuretic, but it doesn't make the patient hypotonic -- keeps the patient isotonic and resuscitation fluid while the surgeon is treating the brain

Front 30

Is hypertonic saline used because of class 1 evidence of efficacy (i.e. evidence-based trials)?

Back 30

No, it's used more anecdotally, but some studies exist that hypertonic saline is pretty safe.

Front 31

If you can't keep the ICP down by draining the CSF, what do you do?

Is this method a safe option?

Back 31

Decompressive Hemicraniectomy -- removing the skull and allowing the brain to expand
--> now due to better anesthesia and faster operations (5min vs. 30min), this is a reasonable operation

Front 32

Why is brain tissue oxygen monitoring done?

Back 32

Keeping ICP equal, better oxygenation = better outcomes

Front 33

What groups are at an increased risk for post-traumatic seizures?

Back 33

*depressed skull fractures
*contusions
*penetrating trauma
*severe head injury
(divided into early, <1wk, and late, >1wk)

Front 34

Is anything done for impact seizures?

Back 34

No AEDs unless they recur

Front 35

Why is managing seizures important?

Back 35

Seizures lead to decreased oxygen and slower recovery of the brain

Front 36

Epilepsy develops in what % of trauma-related seizures?

Back 36

<5%