TBI

Question 1

What protects the brain from injury?

Answer 1

Hair, scalp, skull, meninges, and cerebrospinal fluid (CSF).

Question 2

What is the composition of the intracranial vault?

Answer 2

80% brain tissue, 12% blood, 8% CSF.

Question 3

What percentage of oxygen and glucose does the brain require?

Answer 3

20% of the body’s oxygen and 25% of its glucose.

Question 4

What does the Monro-Kellie Doctrine state?

Answer 4

The volume inside the skull is fixed; an increase in one component (brain, blood, CSF) must be offset by a decrease in another to maintain pressure.

Question 5

How is Mean Arterial Pressure (MAP) calculated?

Answer 5

MAP = Diastolic BP + 1/3 Pulse Pressure.

Question 6

How is Cerebral Perfusion Pressure (CPP) calculated?

Answer 6

CPP = MAP – ICP.

Question 7

What is the normal Intracranial Pressure (ICP)?

Answer 7

Less than 10–15 mmHg.

Question 8

What happens when CPP drops below 70 mmHg in TBI?

Answer 8

Mortality increases—each 10 mmHg drop in CPP raises mortality by ~20%.

Question 9

What is a focal TBI?

Answer 9

A localized brain injury (e.g., skull fracture, hematoma, contusion).

Question 10

What is a diffuse TBI?

Answer 10

Injury affecting a widespread area, such as a concussion or diffuse axonal injury.

Question 11

What is a coup-contrecoup injury?

Answer 11

Coup = impact side injury; Contrecoup = injury opposite the impact.

Question 12

What is the hallmark sign of a concussion?

Answer 12

Post-traumatic amnesia.

Question 13

What causes diffuse axonal injury (DAI)?

Answer 13

Shearing forces from rapid acceleration/deceleration.

Question 14

What is a subdural hematoma?

Answer 14

Bleeding between dura mater and arachnoid; often venous.

Question 15

What is an epidural (extradural) hematoma?

Answer 15

Bleeding between skull and dura mater; often arterial (middle meningeal artery); surgical emergency.

Question 16

What is a subarachnoid hemorrhage?

Answer 16

Bleeding between the pia and arachnoid mater.

Question 17

What is the “mass effect” in TBI?

Answer 17

The space-occupying effect of bleeding/swelling that increases ICP and compresses brain tissue.

Question 18

What are examples of secondary TBI causes?

Answer 18

Hypoxia, hypotension, cerebral ischemia, cerebral edema, herniation, hypercapnia.

Question 19

What is the Cushing’s Triad?

Answer 19

Bradycardia, hypertension (widened pulse pressure), irregular respirations.

Question 20

What are signs of increased ICP?

Answer 20

Headache, vomiting, altered GCS, unequal pupils, posturing.

Question 21

What is decerebrate posturing?

Answer 21

Extension posturing—more severe than decorticate.

Question 22

What SpO₂ is targeted in TBI patients?

Answer 22

≥ 94%.

Question 23

What is the target ETCO₂ for TBI ventilation?

Answer 23

30–35 mmHg (avoid hypercapnia and hypocapnia).

Question 24

When is hyperventilation used in TBI?

Answer 24

As a temporary measure to reduce ICP—but it reduces cerebral blood flow.

Question 25

What systolic BP should be maintained in TBI?

Answer 25

>90 mmHg; ideally 100–110 mmHg.

Question 26

When should you consider early intubation in TBI?

Answer 26

GCS < 9, unprotected airway, or impending airway obstruction.

Question 27

What role do sedatives (e.g. ketamine, midazolam) play in TBI?

Answer 27

Used for airway management and controlling combative behavior; with caution.

Question 28

What is the danger of even a single episode of hypotension in TBI?

Answer 28

It can double mortality.

Question 29

Why is fluid therapy cautiously used in TBI?

Answer 29

To avoid worsening cerebral edema unless hypotensive.

Question 30

What facility should all TBI patients be transported to?

Answer 30

A definitive care hospital with a CT scanner and neurosurgery capability.

Question 31

How should TBI patients be positioned during transport?

Answer 31

Supine, with C-spine precautions.

Question 32

What is a key goal of prehospital TBI management?

Answer 32

Prevent and minimize secondary brain injury.