Week 3 - I - Head injury - when to request a CT head

Question 1

What is the leading cause of death in the UK population aged less than 40 years?

Answer 1

Head injury

Question 2

What are the two types of head trauma remember? (one enters the skull and the other does not)

Answer 2

Missile (penetrating) or Non-missile (non-penetrating)

Question 3

Head injury really is just brain injury Primary brain injury occurs at the time of the insult to the head When does secondary brain injury occur?

Answer 3

Secondary brain injury is further problems that can occur after the primary brain injury

Question 4

Is primary brain injury or secondary brain injury treatable?

Answer 4

Primary brain injury is not treatable but the secondary brain injury is treatable

Question 5

What is the Monroe Kellie Hypothesis for Intracranial pressure?

Answer 5

The skull is an inelastic closed box of constant volume The skull contains the brain, blood and CSF. A an increase in volume of one component must be compensated by a decrease of volume of another component or the ICP will rise

Question 6

How is the cerebral perfusion pressure calculated? What is the minimum the cerebral perfusion pressure should be? What is the normal range for CPP?

Answer 6

CPP = MAP - ICP Minimum cerebral perfusion pressure should be no less than 60mmHg Normal range is 70-105mmHg

Question 7

If the systolic BP is 120 and the diastolic is 80, what is the MAP? What is the normal range for the intracranial pressure?

Answer 7

MAP = 2DBP + SBP all dividied by 3 MAP = 2x80 + 120 = 280 divided by 3 MAP = 93mmHG Normal intracranial pressure range = 5-13mmHg

Question 8

Skull fractures can be linear or compound (or depressed). What is the difference between a linear and a compound fracture? (compound is often worse)

Answer 8

Linear fracture is a striaght sharp fracture line that may cross sutures Compound fracture is deeper and there are complete scalp lacerations - pathway to the intracranial cavity

Question 9

The skull base consists of the anterior, middle and posterior cranial fossa Which fossa do the majority of skull base fractures occur? (basilar skull fractures refers to fractures of the skull base)

Answer 9

The majority of skull base fractures occur in the anterior cranial fossa

Question 10

What is the sign known as in anterior cranial fossa fractures? (pic on left) What is the sign known as in posterior cranial fossa fractures?

Answer 10

Anterior cranial skull fractures - Raccoon eyes Posterior cranial skull fractures - Battle sign - bruising over the mastoid process (ecchymosis is bruising)

Question 11

What test is used to assess a patients level of consciousness? What are the different sections of this test?

Answer 11

Glasgow coma scale Eye opening response - 4 Best verbal response - 5 Best motor response - 6

Question 12

What is the glasgow coma scale for a coma? What is the glasgow coma scale score range?

Answer 12

Score for a coma in the GCS is 8 and less COma - do not open eyes, do not obey commands, do not speak The score ranges from 3-15

Question 13

What is abnormal flexion in a patient known as? What is abnromal extension known as? Which is thought to be worse?

Answer 13

Abnormal flexion - decorticate - co for cold so body flexes Abnormal extension - decerebrate - decerebrate is worse than decorticate

Question 14

Hypoxia, hypotension and raised ICP is usually what kills patients with head injury

What would a CT head scan should be requested in a patient with head trauma?

• (attached is a link for when you would CT scan an adult or child after head trauma https://www.nice.org.uk/guidance/cg176/resources/imaging-algorithm-pdf-498950893)

Answer 14

For adults who have sustained a head injury and have any of the following risk factors, perform a CT head scan within 1 hour of the risk factor being identified:

• GCS less than 13 on initial assessment in the emergency department.
• GCS less than 15 at 2 hours after the injury on assessment in the emergency department.
• Suspected open or depressed skull fracture.
• Any sign of basal skull fracture (haemotympanum, ‘panda’ eyes, cerebrospinal fluid leakage from the ear or nose, Battle’s sign).
• Post-traumatic seizure.
• Focal neurological deficit.
• More than 1 episode of vomiting.

Question 15

Extradural haemoatomas often can be the one someone has a head knock and then feels ok for a few hours (might have a headache) then collapses and can die due to having a slow bleed forming an extradural haematoma What is the period of feeling okay known as?

Answer 15

This is the lucid interval in the patient

Question 16

Where can CSF leak after a head injury?

Answer 16

CSF ottorhea - can leak through the ear CSF rhinorrhea - can leak out of nose Increases ris of infection