Exam 2: TBI

Question 1

Let’s review some patho for TBIs:

Answer 1

Brain is contained w/i the cranium
→ Cranium is irregular and sharp
Brain is suspended in cerebrospinal fluid. Fragile AF.
→ Like jello (yummy)
TBI occur d/t force to cranium and brain with a secondary injury d/t cerebral edema and increased intracranial pressure
→ External mechanical force
→ NOT degenerative or congenital in nature

Question 2

There is an increase in incidence with which two populations?

Answer 2

Inc incidence in younger males and old folks

Question 3

There is a lot of terminology with TBIs. What is an acceleration injury?

Answer 3

External force contracting head, placing head in motion.

Question 4

There is a lot of terminology with TBIs. What is deceleration injury?

Answer 4

Moving head suddenly stops

Question 5

Two types of TBI?

Answer 5

Direct and indirect

Question 6

Describe a direct TBI:

Answer 6

Sudden and profound injury to the brain
→ Considered “complete” at the time of impact
→ Examples:
GSW
Blow to the head
Fall

Question 7

Describe an indirect TBI:

Answer 7

Injury from force applied to another body part with rebound effect
→ Movement of the brain w/i the skull
→ Examples:
Whiplash
Rear end MCV
Shaken baby syndrome

Question 8

Like many things, there are also categories of primary and secondary injuries. Describe the difference.

Answer 8

Primary
→ Damage at time of injury

Secondary
→ Injury process after initial injury
→ Includes physiological vascular and biochemical events as extension of the primary injury
→ Worsening of initial primary injury
→ Pt outcomes worsen

Question 9

Primary injuries can be further broken down into:

Answer 9

Focal or diffuse
→ Focal is a specific area of localized damage
→ Diffuse is many areas. Typically microscopic and many nit be seen on imaging until necrosis occurs

Question 10

What are some causes of secondary TBI injuries?

Answer 10

Hypotension → MAP < 65
Hypoxia → PaO2 80-100
Increased intracranial pressure (aka intracranial hypertension)
Cerebral edema

→ If thins prevent O2 and glucose from getting to the brain
→ If cerebral hypoxia occurs prognosis is poor; no glucose = cellular death

Question 11

Describe secondary TBI injury patho:

Answer 11

Skull does not expand
Brain tissue is soft - is vulnerable to injury
→ Brain tissue + CSF + blood
Intracranial pressure should be 10-15 mmHg
→ >20 mm Hg neurons die
To maintain ICP brain can
→ Shunt CSF to spinal subarachnoid space
→ Reduce cerebral blood flow
→ w/o blood flow → no O2 → ischemia → cell death

Question 12

What is the difference between an open and closed injury w/TBI?

Answer 12

Open
→ Skull fracture or pierced
→ Brain and dura contaminated
→ Examples:
* Foreign object penetration
* Linear
* Depressed
* Comminuted
* Basilar

Closed
→ Skull maintains integrity
→ Compilations with ICP
→ Examples:
* Contusion
* Cerebral lacerations

Question 13

What are some things to watch for with a basilar skull fracture?

Answer 13

May result in the following
→ Leakage of CSF from the nose (CSF rhinorrhea) or ear (CSF otorrhea)
→ Blood behind the tympanic membrane (hemotympanum) or in the external ear canal of the tympanic membrane has ruptured
→ Ecchymosis behind the ear (battle sign) or in the periorbital area (raccoon eye)
→ Loss of smell or hearing, which usually immediate although these losses will not be noticed until the pt regains consciousness
→ Facial nerve function may be imparied immediately or after a delay
→ HALO SIGN

Question 14

What is a halo sign?

Answer 14

A “halo” or “ring” sign, occurs when cerebrospinal fluid (CSF) mixes with blood on an absorbent surface. The blood forms a spot in the center and a lightly stained ring forms a halo around it.

Question 15

Describe the symptoms of a MILD TBI:

Answer 15

→ May feel dazed disoriented or have loss of consciousness (up to 30 min)
→ May have loss of memory before or after injury
→ No evidence of brain damage on imaging
Wide range of physical and cognitive sx
→ Symptoms usually resolve in 72 hrs but may last longer up to months

Question 16

Describe the symptoms of a MODERATE TBI:

Answer 16

→ Period of loss of consciousness from 30 min up to 6 hrs
→ GCS 9-12
→ May see focal or diffuse brain injury on imaging
→ May have acute amnesia up to 24 hours
→ Likely require a hospital stay, may or may not require ICU

Question 17

Describe the symptoms of a SEVERE TBI:

Answer 17

→ Loss of consciousness for > 6 hrs
→ GCS 3-8
→ Focal and diffuse damage to the brain vessels and or ventricles
→ Able to see injury on imaging in early stages
→ Require ICU level care ICP monitoring

Question 18

Name some complications of TBIs.

Answer 18

Brain bleed
Hydrocephalus
→ Abnormal collection of CSF
→ Inc ICP
Autoregulation impairment
→ More severe injury - the more this will be impacted
→ Hypotension
→ Dysrhythmias
Resp comp
→ Hypoventilation
→ Hypocarbia
→ Hypoxia
CSF leak
→ Inc risk for infection

Question 19

Talking about ICP: What is the timeframe we are looking at with this?

Answer 19

Initial injury - 4 days after

Question 20

What is normal ICP?

Answer 20

10-15 mmHg

Question 21

At what measurement do we see neuron death?

Answer 21

> 22 mmHg
*FYI increased ICU is the most common cause of death in TBI

Question 22

Increased ICP can lead to ___________.

Answer 22

Herniation

Question 23

Going waaaay back: What’s the Cushing Triad?

Answer 23

→ Bradycardia
→ Hypertension - widening pulse pressure
→ Irregular respiratory rate

Question 24

What is an uncal herniation?

Answer 24

→ Shift of temporal lobe (uncus)
→ Pressure on oculomotor nerves
→ Dilated nonreactive pupils

Question 25

Describe central herniation:

Answer 25

→ Shift downward - towards brain stem
→ Cheyne-strokes resp
→ Pinpoint nonreactive pupils
→ Hemodynamic instability

Question 26

I’m not getting into all the s/s and assessments.

Answer 26

You know that shit.

Question 27

Name 3 strategies to reduce ICP:

Answer 27

→ Prevent coughing / bearing down
→ HOB 30-45 degrees
→ Do not cluster care, lights down, low stimulus

Question 28

Name a few other ways we would manage ICP/TBI:

Answer 28

BP management
O2
Seizure precaution
→ Antiepileptics
Sedation and / or barbiturate coma
→ Must be on vent

Question 29

Name meds we would use for sedation (3) or barbiturate coma (2):

Answer 29

Sedation: Fentanyl, propofol, versed
Barbiturate: Pentobarbital, thiopentone

Question 30

What is a med we would use to treat cerebral edema that is an osmotic diuretic that crosses the BBB?

Answer 30

Mannitol

Question 31

If you stop Mannitol you might get ______. ____________.

Answer 31

Rebound swelling
ometimes use Lasix to help with that.

Question 32

If you stop Mannitol you might get ______. ____________. And what might you use to avoid this?

Answer 32

Rebound swelling
→ Sometimes use Lasix to help with that.

Question 33

Mannitol requires ____________ tubing.

Answer 33

Filtered

Question 34

Things to monitor while on Mannitol:

Answer 34

→ Renal function
→ Osmolarity (goal 310-320)
→ Electrolytes
→ Weakness
→ Edema

Question 35

What is our goal osmolarity?

Answer 35

310-320

Question 36

What is something you can get with a TBI (a disease state)?

Answer 36

Diabetes insipidus
→ NOT related to diabetes - this is hormonal
→ Too little vasopressin (antidiuretic hormone)
→ Disorder of salt and water metabolism
→ Intense thirst
→ Extreme urination
→ If your foley shows urine going from straw colored to clear

Question 37

How do you treat diabetes insipidus with a TBI?

Answer 37

→ Vasopressor
→ IVF

Question 38

What is SIAH?

Answer 38

Syndrome of inappropriate antidiuretic hormone
→ Too much vasopressin (antidiuretic hormone)
→ Retention of fluid
→ Electrolyte imbalance
→ Low Na level

Question 39

SIAH treatment?

Answer 39

Hypertonic saline (3%)
Central line
→ EXTREME VESICANT
ICU level care
Monitor labs closely

Question 40

Let’s talk about 3 surgical interventions for TBI:

Answer 40

ICP monitoring
→ Burr hole
Decompressive craniectomy
→ Remove section of the skull
→ May be reimplanted later
→ Dec ICP - allow brain to explain
→ May remove ischemic tissue
→ Precaution - positioning orders - helmet when OOB
Craniotomy
→ Removal of ischemic brain matter blood etc
→ Return skull back after

Question 41

What should you say if someone wants to discuss organ donation with you?

Answer 41

NO
Nurses don’t talk about this. Refer to a rep or team member from the org. In NC this is Lifeshare of the Carolinas.

Question 42

Brain death is determined by _____.

Answer 42

MD

Question 43

What are the 3 key essentials that determine brain death?

Answer 43

Irreversible unresponsive coma
→ Brain angiogram - determine cerebral blood flow
→ Scalp blood flow needs to be temporary stopped to obtain accurate imaging
Absence of brain stem reflexes
→ Oculovestibular reflex (50 ml cold water in ear), corneal reflex, oculocephalic reflex
Apnea
→ Vent - place on spontaneous resp mode