Case 10 - acute head trauma Flashcards
how many people per 100000 of the population will suffer a head trauma
453 per 100,000
what is the percentage that are considered moderate to severe
10.9%
how many admissions throughout the year
350,000
what are the risk factors for a head trauma
male
young (15-30) and old (65+ tend to be more low impact and falls )
urban areas
substance misuse including alcohol
what are primary preventions put in place
seat belts
helmets
alcohol prevention and limits
health and safety
what is the first aid carried out for suspected head trauma
ABC + C-spine
what is pHEMS
pre hospital emergency medicine
what is ATLS
trauma protocol
what is involved in the history part of the assessment
From patient and collateral (passersby or paramedics or family)
Time - when did it occur and was patient just found
Mechanism - high impact or fall form standing?
Conscious level - at worst: this is very important as can be a worrying sign
Seizures
PMHx (past medical history) / DHx (drug history)
what is the A-E of the assessment protocol
Patency
Other injuries, apnoea, hypoxia
Other injuries, hypotension, heart ray
GCS, pupils, C-spine (10% of head injury patients have a c spine injury as well)
Primary survey (entire body)
what are the signs of a base of skull fracture
racoon eyes
battle sign
haemotypanum - bleeding behind the ear drum
- CSF leak - clear fluid from the nose
what percentage have a concurrent C-spine injury
5-10% have a concurrent C spine injury
glasgow coma score diagram
what are the NICE guidelines for a CT
perform a CT head within 1 hour of the risk factor being identified
GCS less than 13 on initial assessment in the emergency department
GCS less than 15 after 2 hours after the injury on assessment in the ED
Suspected open or depressed skull fracture
Any sign of basal skull fracture - panda eyes, fluid leaking or Battle’s sign
Post traumatic seizure
Focal neurological deficit
More than 1 episode of vomiting
what adults who have had loss of consciousness or amnesia since the injury would have a CT within 8 hours of the head injury
age 65 or older
any history of bleeding or clotting disorders
dangerous mechanism of injury
more than 30 mins retrograde amnesia of events immediately before the head Injury
what is the primary in brain injury
the original insult
what is the secondary in brain injury
the damaged caused after
caused by:
hypoxia
hypotension/hypertension
raised inter cranial pressure
types of head trauma diagram
what is a diffuse axonal injury
when the brain moves back and forth in the skull cavity - ricochets
what is an extradural haematoma
any bleeding that happens within the potential space between the skull and the dura
what is the bleeding usually from in an extradural haematoma
middle meningeal artery
what is the conscious pattern in an extradural haematoma
usually lose consciousness immediately but then regain consciousness
what are the other symptoms of extradural haematoma
ongoing headache and then become increasingly drowsy after some hours
CT scan of an extradural haematoma
when do sub dural haematomas usually occur
these occur following trauma but more frequently from falls
what is the consciousness pattern with sub dural haematomas
gradual loss of consciousness
where is the bleeding from in a sub dural haematoma
venous bleed and between venous bridging veins
sub dural haematoma on CT scan
effects of secondary brain injury
what is the murno Kellie
everything managed in the brain must be done so in equilibrium
what are the three components to the murno Kellie
brain
CSF
blood (venous and arterial)
can there be a degree of compensation
yes but only for so long
pathophysiology diagram
diagram explaining how to measure the CPP needed
what is normal ICP in the brain
10mmHg
when does autoregulation stop working
when blood pressure drops below 50
when will cerebral vasculature start to dangerously constrict
when BP is over 150
how do you measure inter cranial pressure
neurosurgeons place inter cranial pressire wires in parenchymal or intra dural space
what is normal range for ICP
5-12mmHg
what happens if you have a higher ICP than the mean arterial pressure
means that there is no blood flow going into the brain - no pressure to push blood into the brain
diagram showing the left being normal and right being abnormal
what is the equation for cerebral perfusion pressure
MAP - ICP
what is MAP
the number in brackets beside BP
what is the bit we are most concerned about
CPP
what is the importance of venous drainage
if we can ensure there is adequate venous pressure this can improve overall pressure
what are the signs of schema
hypoxia
Hypotension
Loss of auto regulation
raised ICP
Oedema
Haematoma
Hydrocephalus - when haematoma obstructs the ventricular system: no ability to drain CSF and increase pressure
Vasospasm
Microvascular pathology
what is cytotoxic oedema
initial mechanism
Fluid retained in cytoplasm
Loss of NaK ATPase
Glutamate gated Ca channels open
Ca draws water in
what is vasogenic cytotoxic
delayed mechanism (48 hours) gets worse after 48 hours
Breakdown of blood brain barrier
Fluid and protein extravasation into parenchyma
what is a subfalcine herniation syndrome
midline shift on CT
what is a transtentorial herniation syndrome
pressure on the brainstem
oculomotor nerve - pupils
what is tonsillar herniation syndrome
through foremen magnum
medulla - cardiorespiratory centre
what is the medical management Maintain physiology:
MAP >90 or CPP >60
Normocapnia
Normothermia
Avoid hypoxia
Improve venous drainage
head up
No restrictions
Reverse coagulopathy
Anti-epileptics if indicated
what does the prognosis rely on
age
presenting GCS
co-morbities
episodes of hypoxia or hypotension
pupillary response
duration ICP >20
country
what is the website you can use for head injure prognosis
CRASH website
very overall and average and not individual to the patient
GCS outcome score diagram
