Head Trauma in the ED Lecture Powerpoint

Question 1

Intracranial pressure (ICP)

Answer 1

Pressure exerted by fluids such as CSF and blood inside the skull (rigid nonexpandable box) on prain tissue, normal is 7-15 mmHg (average 10mmHg), for supine adult, >20 is abnormal, >40mmHg is severe, sustained increased ICP leads to decreased brain function and poor outcome

Question 2

Compensated state of ICP

Answer 2

When an individual has a brain bleed (or enlarging mass), CSF and venous volume decrease to maintain normal ICP in a compensatory manner (brain mass and arterial volume unaffected) if overwhelmed see drop in arterial volume leading to ischemia of the brain or herniation of brain tissue

Question 3

ICP monitoring types (3)

Answer 3

• Intraventricular (can be used to drain CSF as well - therapeutic as well)
• subdural
• intraparenchymal (in the brain tissue itself)

Question 4

Cerebral perfusion pressure (CPP)

Answer 4

Difference between mean arterial pressure (avg between systolic and diastolic) and intracranial pressure, a net pressure gradient that drives oxygen delivery to brian tissue but not actually a measure of cereral blood flow, normal range 60-70 mmHg (CPP=MAP-ICP), if CPP too low can raise blood pressure or decrease ICP, requires ICP monitor placement first

Question 5

Primary vs secondary brain injury

Answer 5

-Occurs at time of impact vs occurs at some point after moment of impact, often preventable and very important to control in emergency setting (hypotension, hypoxia, hypoglycemia, hyperthermia, hypocapnia)

Question 6

Systolic blood pressure value in head injury patients need in order to prevent secondary injury

Answer 6

90mmHg

Question 7

Do intracranial bleeds cause hypotension?

Answer 7

No because of the rigidity of the cranium - if hypotensive might have some other type of shock going on

Question 8

Cushings triad

Answer 8

Seen as result of and indicates increased ICP

• hypertension
• bradycardia
• irregular respiration

Question 9

Labs to draw on suspected head trauma patient*** (5)

Answer 9

• CBC
• CMP
• Coags***
• ABG
• tox screen

Question 10

Minimum required radiologic studies for head injury patient (2)

Answer 10

• Head CT w/o IV contrast

- cervical spine CT w/o IV contrast

Question 11

Closed vs open brain injury

Answer 11

Skull not broken, fractured, or penetrated vs sees dura and brain tissue communicating with outside world

Question 12

Traumatic brain injury severity classification (TBIs) (3)

Answer 12

• Mild, synonymous with concussion (GCS 13-15 and some kind of mechanism of injury, can see confusion, amnesia, stumbling)
• Moderate (GCS 9-12, similar symptoms to mild, need admission to ICU and administration of antifibrinolytic tranexamic acid (TXA))
• Severe (GCS 3-8, minimally responsive, need admission to ICU and managed with TXA but not nearly as effective, same principles of eliminating secondary brain injury)

Question 13

How to determine who with a mild TBI gets a head CT criteria? (10)

Answer 13

• retrograde amnesia >30min
• suspicion of skull fracture
• suspicion of basilar skull fracture
• 2 or more episodes of vomiting
• use of any anticoagulant
• age >60
• seizure since episode of injury
• neurologic deficits
• high impact mechanism
• intoxication or abnormal behavior

Question 14

Return to learn and return to play protocol for mild TBI/concussion

Answer 14

• may return to school once able to concentrate on a task and tolerate visual and auditory stimulation for 30-45 min
• return to play over 6 stage course of non contact activity gradually increasing to normal level, may need referral if symptoms persist 21 days or longer or if uncertain diagnosis of concussion

Question 15

Diffuse axonal injury (DAI)

Answer 15

traumatic shearing of the axons that occur when head is rapidly accelerated/decelerated and by secondary biochemical cascades, occurs in white and grey matter and majority end up in post traumatic coma as result, may have relatively normal head CT but exam with severely diminished GCS, generally confirmed by MRI, death rare as has no effect on brainstem

Question 16

General principals for TBI treatment (4)

Answer 16

• Involve neurosurgery
• head of bed 30 degrees
• Pharm DVT prophylaxis from stable repeat head CT
• keppra for seizure prophylaxis

Question 17

Epidural hematoma

Answer 17

Collection of blood between dura and skull, 80% of skull fractures, an arterial bleed affecting middle meningeal arteries and can lead to herniation if untreated, see initial brief loss of consciousness then rapid neuro deterioration, fixed dilated pupil on unilateral side

Question 18

Subdural hematoma

Answer 18

More common than epidural hematoma, occurs from shearing force on venous bridging veins between dura and arachnoid, commonly due to acceleration or deceleration injuries, space occupying lesion causing concave hematoma, can be acute or chronic and many relatively asymptomatic, causes midline shift of structures to one side due to the space occupying lesion

Question 19

Traumatic subarrachnoid hemorrhage

Answer 19

Venous bleeding in subarachnoid space between arachnoid and pia mater, usually associated with other hemorrhage, not space occupying, may increase ICP and block outflow of CSF from ventricles, if isolated may be aneurysmal in origin

Question 20

Cerebral contusion

Answer 20

Bruise of brain tissue that primarily occurs in cortical tissue when the brain collides with bony protuberances on inside surface of the skull, frontal/temporal lobes most commonly affected, frequently associated with edema which can be a cause of elevated ICP, sometimes mislabeled as an intraparenchymal/intracerebral hemorrhage

Question 21

Coup vs contrecoup injury

Answer 21

Coup is at the site of impact with an object, contracoup is on the opposite side of the area the object was hit, can occur individually or together

Question 22

3 types of skull fractures

Answer 22

• Linear (extends thru full thickness, most common, often without significance unless cross middle meningeal artery groove which then causes a lot of bleeding)
• Depressed (leaves impression on skull, often involves brain parenchymal injury)
• Basilar (fracture thru posterior or anterior skull base, most often petrous portion of temporal bone or occipital bone, can cause CSF leaks, increased risk of meningitis)