Traumatic brain injury

Question 1

Define traumatic brain injury

Answer 1

An alteration in brain function or other evidence of brain pathology caused by an external force

Question 2

What are the common mechanisms that can cause a TBI?

Answer 2

MVC/MCC/ Car vs ped
Fall
Industrial accident
Assault
Sports injury

Question 3

In regards to TBI, what is a coup?

Answer 3

Any blow to the skull

Question 4

In regards to TBI, what is countrecoup?

Answer 4

Blow to the head where the impact transfers through the skull to the opposite side of the head causing damage to the side opposite the initial point of injury

Question 5

A patient with a mild TBI can present with

Answer 5

Headache
Confusion
Dizziness
Memory impairment
Blurred vision
Behavioral changes

Question 6

A patient with a moderate TBI can present with

Answer 6

Repeated nausea or vomiting
Slurred speech
Weakness in arms or legs
Problems with thinking or learning

Question 7

A concussion is formally referred to as:

Answer 7

A diffuse axonal injury

Question 8

Describe the damage that is associated with a diffuse axonal injury

Answer 8

Centripetally applied forces can damage nerve fibers by shearing the fiber or disrupting the myelin sheath
Can result in varying degrees of coma or death

Question 9

Where is an epidural hematoma located?

Answer 9

Between the skull and the dura

Question 10

Where is a subdural hematoma located?

Answer 10

Between the dura and the arachnoid mater

Question 11

Where is a subarachnoid hemorrhage located?

Answer 11

Beneath the arachnoid mater within the subarachnoid space

Question 12

Describe the Monroe-kelli doctrine

Answer 12

There is a limited amount of space in the brain
To compensate for swelling or a mass, the body will remove CSF and venous volume to try to accommodate for the growth.
This is limited and eventually pressure will rise in the intracranial space

Question 13

What is a normal ICP for a supine patient?

Answer 13

10-15 mmHg

Question 14

When does brain death occur due to increased ICP?

Answer 14

When ICP=MAP

Question 14

What ICP is the ceiling for most ICU patients?

Answer 14

20 mmHg

Question 14

What happens if ICP is 15-20 mmHg?

Answer 14

Capillary beds are compressed altering microcirculation

Question 15

What happens if ICP is between 30-35 mmHg?

Answer 15

Provokes edema

Question 15

What happens if ICP is between 40-50 mmHg?

Answer 15

Does not support perfusion

Question 15

How do we calculate cerebral perfusion pressure?

Answer 15

CPP = MAP-ICP

Question 16

What does a cerebral perfusion pressure of less than or equal to 50 cause?

Answer 16

Frank cerebral ischemia

Question 16

What have recent studies shown regarding Cerebral perfusion pressure?

Answer 16

Poor outcomes for patient with CPP of less than or equal to 60

Question 16

What is a normal Cerebral Perfusion Pressure? CPP

Answer 16

95-80 mmHg

Question 17

What are the categories of responses for the glasgow coma scale?

Answer 17

Eye opening response
Verbal response
Motor response

Question 18

What are the eye opening response levels

Answer 18

Spontaneously
To speech
To pain
None

Question 19

What are the verbal response levels?

Answer 19

Oriented to time, person, place Confused Inappropriate words Incomprehensible sounds No response

Question 20

What are the motor response levels

Answer 20

Obeys command Moves to localized pain Flex to withdraw from pain Abnormal flexion Abnormal extension No response

Question 21

When does the glasgow coma scale indicate intubation?

Answer 21

Intubation is indicated for GCS < 9

Question 22

Describe decorticate posturing

Answer 22

Patient pulls arms up to chest with palms facing down

Question 23

Describe decerebrate posturing

Answer 23

Patient puts hands by sides with palms rotated inward and outward

Question 24

A patient you are assessing has pupils that are large and unresponsive to light. The patient is not on drugs, what is this indicative of?

Answer 24

Increased ICP leading to paralysis of the optic nerve

Question 25

What is the fancy term for a blown pupil?

Answer 25

Mydriasis

Question 26

Impending or ongoing cerebral herniation can be indicated by what?

Answer 26

Posturing Pupillary asymmetry Mydriasis Cushing triad

Question 27

What is cushing triad?

Answer 27

Hypertension Bradycardia Irregular respiration

Question 28

When referring to a TBI, what is meant by the term midline shift?

Answer 28

The compression or movement of the ventricles on one side of the brain in response to swelling

Question 29

What can happen if ICP remains unchecked?

Answer 29

Brain can be pushed out of its normal position

Question 30

Describe secondary brain injury

Answer 30

A cascade of subtle changes in the brain and nervous system following a primary injury

Question 31

What changes can cause secondary injury in the brain?

Answer 31

Cerebral edema Inflammation Electrolyte imbalances Hypoxemia Poor BP control Poor glucose management Poor vent management Seizures

Question 32

What is the cause of cerebral edema in most adults?

Answer 32

Vasogenic edema

Question 33

What causes cerebral edema?

Answer 33

Increased permeability of the cerebral vasculature/ breakdown of the blood brain barrier

Question 34

What are management options for cerebral herniation

Answer 34

Hyperosmolar IV solutions External ventricular drains Evacuation of blood clot Craniectomy

Question 35

How do hyperosmolar solutions manage cerebral herniation?

Answer 35

Increased salinity of blood pulls fluid out of tissue reducing swelling Generally 3% hypertonic saline

Question 36

Describe how extraventricular drains can manage cerebral herniation

Answer 36

A catheter is placed in cerebral ventricle allowing for pressure monitoring and fluid drainage to control ICP

Question 37

What is respiratory’s role in traumatic brain injuries?

Answer 37

Prevent second degree brain injury Gentle intubations Management of ventilation Management of oxygenation

Question 38

What effects can hyperventilation have on TBI patients?

Answer 38

PaCO2 < 25 mmHg can rapidly decrease ICP Can also reduce blood flow to the brain

Question 38

Why is a gentle intubation important with TBI patients?

Answer 38

Intubation can stimulate supraglottic larynx which somehow can spike ICP

Question 39

What should providers be aware of when choosing PEEP settings for patients with TBIs?

Answer 39

Increased intrathoracic pressure inhibits venous return to the heart which can increase ICP Problematic because PEEP is what we use to promote oxygenation

Question 40

What are the guidelines regarding hyperventilating TBI patients?

Answer 40

Prophylactic hyperventilation should be avoided PaCO2 of 25-30 mmHg can sometimes be used as a temporary measure to resolve and ICP crisis Hyperventilation induced vasoconstriction can cause secondary ischemia and worsen patient outcomes

Question 41

When can hyperventilation of TBI patients be especially harmful?

Answer 41

In the acute phase, 24-48 hours after injury

Question 42

If a patient with a TBI experience mental status changes, what needs to be performed?

Answer 42

A CT scan