Applied physiology:The Clinical Management of Traumatic Brain Injury Flashcards
How prevalent is Traumatic Brain Injury (TBI) in Scotland?
Scotland:
- 1998 and 2009 there were 208,195 recorded episodes of continuous hospital care in Scotland as a result of TBI
- 90-95% are mild injuries
In Scotland estimated 6.6% ED are head injuries
UK;
- Its a major mortally, morbidity - head injury most commonest cause of death a disability in 1-40 years old in the UK
- 1,4 million patients per year in Wales and England - 33-50% children
- UK 200,000 admissions per year
Dead incidence 0.2% of all patients attending ED
Globally;
- Over 50 million per year
- High income countries numbers of TB in elderly increases
- TBI deaths are 30-40% of all injury related deaths
- TBI costs US $400 billion annually
- EU 2-5 million new cases each year
Who is most likely to have a Traumatic Brain Injury ?
Affects 1.5 males/1 female
Under 0-4 years, 15-19 and over 75’s
Falls, Road traffic Accidents (RTA) and Assults are the major cause
Its a major mortally, morbidity - head injury most commonest cause of death a disability in 1-40 years old in the UK
What is Traumatic Brain Injury?
Traumatic Brain Injury is external forces causing damage to the brain
You can get many different types that all vary in severity from mild to moderate to severe
Examples include;
- Depressed fractures
- Degree of injury
- Suture fracture
- Basal fracture
- Intracranial in parenchma
- Contusion
- Concussions
Haemorrhage;
- Pidural
- Subdural
- Subarachnoid
How have traumatic brain injury cases changed over the years?
We have more advanced technology to protect us now but it is dependent on use to use them
How can sport cause Traumatic Brain injury (TBI)?
Repeated concussions and trauma can cause issues later in life e.g seen in boxers
What is Primary Brain Injury?
The instant injury and occurs at the moment of impact
Pattern & extends of damage depends on nature of impact
Not treatable (public health issue)
Can be caused by car accidents, cycling accidents, being drunk etc
What s shaken baby syndrome?
Shaken baby syndrome - traumatic brain injury from shaking, neck is very flexible and get hyperextension and hyperflexion with brain hitting front and backwards getting damage
What coup contrecoup injury ?
Contrecoup injuries classically occur when the moving head (brain) strikes a stationary object (brain hitting skull)
whereas, a coup injury is associated with a moving object impacting a stationary head (head hits dash)
How should you manage head injury early on ?
- Prehospital management
- Immediate management of scene
- Assessment in the E&R
- Investigating Pre-emitive investigations
ABC (Airway, breathing, Circulation)
Disability (GCS - Glasgow Coma Scale)
Cervical spine immobilisation
How should you optimise oxygenation?
When assessed in pre admission SpO2 is < 90% in 50% of cases (hypoxic)
Open airway but….
How should you use GCS to rank the degree of Head Injury ?
E4 V5 M6 GCS 15/15
Degree of head injury;
Mild 13-15
Moderate 9-12
Severe 8 or less
If severe immediately intubate in case breathing lowers or stops was unconscious
How is the Glasgow Coma Scale Eye Opening section scored?
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How is the Glasgow Coma Scale Verbal section scored?
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How is the Glasgow Coma Scale Motor section scored?
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Who do we send to hospital after suffering brain injury?
Who we are sending to hospital;
- Under 5 year old
- Over 65 year old
- Amnesia
- Loss of consciousness
- High energy injury
- Vomiting
- Seizure
- Bleeding/clotting disorders
What is secondary brain injury?
Secondary brain injury (e.g raised intracranial pressure, oedema);
Secondary processes which occur at the cell and molecular level to exacerbate neurological damage;
- Neurotransmitter release (glutamate)
- Free radical generation
- Calcium mediated damage
- Inflammatory response
- Mitochondrial dysfunction
- Early gene activation (Currently being tried to prevent inflammation increasing in body - just in trial stages to prevent cell death)
How can we minimise secondary brain injury ?
How to minimise secondary brain injury ?
- Optimise oxygenation
- Optimise cerebral perfusion (would preferably use hypertonic, if not isotonic)
- Blood glucose
- Hypocapnia/hypercapnia
- Body temperature ( Every degree increased increases metabolic rate)
What is the Monro-kellie doctrine?
The Monro-Kellie doctrine or hypothesis states that the sum of volumes of brain, cerebrospinal fluid (CSF) and intracerebral blood is constant. An increase in one should cause a reciprocal decrease in either one or both of the remaining two.
What is cerebral perfusion pressure directly proportionate to?
CPP = MAP - ICP
CCP (cerebral perfusion pressure)
MAP (Mean arterial pressure)
- Diastolic pressure + 1/4 pulse pressure or DP + 1/3 (SP-DP)
ICP (intracranial pressure)
What is the pathophysiology of how primary brain injury causes secondary brain injury?
Image
What are some features that suggest there is a risk of an intracranial mass ?
History;
- High impact injury
- Significant retrograde amnesia
- History of coagulopathy (Haematoma could continue bleeding)
- Post traumatic seizure
Examination;
- GCS 12/15 or less
- GCS 13/15 or 14/15 and failing to improve within 2 hours of injury
Clinical signs of skull fracture!
What are red flags and reasons we would not discharge this patient?
Red flags;
- Loss of consciousness, drowsiness, confusion, fits
- Painful headache which doesn’t settle, vomiting Orr visual disturbance
- Clear fluid from ear or nose, bleeding from ears, new deafness (CSF rhinorrhoea test for glucose
or beta 2 transferrin)
- Problems understanding or speaking, loss of balance, difficulty walking or weakness in arms or legs
What must we keep can eye on in breathing?
- If we should administer oxygen ?
- Monitor SpO2
- Monitor ABG’s
- GCS < 8 intubate
Why is it important that we immobilise the patient as soon as possible?
There is potentially a fracture here - need to think about spinal cord damage
Plain x-ray is the investigation of choice - Often CT cervical spine
What drugs should we consider prescribing?
Tranexamic Acid helps blood to clot
Why is monitoring CO2 important?
Cerebral vessel diameter (and CBF) changes over a wide range of PaCO2
Target directed therapy;
PaCO2 4.5-5.0 kPa
CO2 will increase vasodilatation as tissue wants more oxygen, vascularisation and oedema increase
What should we do in order to prevent a risk of deterioration later?
Supply versus demand
- Optimise oxygen supply
Minimise demand;
- Convulsions (seizure) occur in 15% of severe head injuries - treat with phenytoin in early head injury
- Brain metabolic rate increase 6-9% for every degree rise in temperature - treat pyrexia
Think about sedation (propofol/midazolam)
What should you do when contacting a neurosurgeon ?
State;
- Mechanism of injury
- Age of patient
- Respiratory and cardiovascular status
- GCS score & pupil response
- Alcohol/drugs
- Associated injuries
- Results of CT scan
Why is pupil response so important ?
If no response patient condition is plummeting, near death
How would ICU manage intracranial hypertension?
- ICP monitoring (IC perfusion?)
- Osmolar therapy
- Decompressive craniotomy
- Hypothermia
- Venous Thromboembolism - Prophylaxis
- Stress ulcers Prophylaxis
- Seizure Prophylaxis
- Nutrition
How do ICU act according to patients?
ICU don’t need to know in detail, divide patients and act according to tier
What should you think when it comes to glucose?
Glucose
Tight control of blood glucose has been shown to
improve outcome
BUT dangers of unrecognised hypoglycaemia…
(What is the optimum target for blood glucose after
traumatic brain injury?)
Remember enteral nutritional support
What might peri-orbital bruising show?
Anterior cranial fossa fracture?
Basal skull fracture?
What is Battle’s sign?
See image
Petrous temporal bone fracture? Bruising might take time to develop
Might see CSF from ear
When should you immediately request a CT scan in adults?
Immediately request a CT scan in adults if;
- GCS <13 on initial assessment
- GCS <15 2 hours after injury
- Open or suspected depressed skull
- Any sign of basal skull injury ? (battles sign)
- Post traumatic seizure
- 1 or more episodes of vomiting (3 in kids) (Intracranial pressure increased)
- Amnesia for events more than 30 mins before impact
What are the features of extradural haematoma?
Extradural haematoma;
- Relatively uncommon
- Strongly associated with skull fracture
- Middle meningeal artery
- 1/3 due to venous bleeding
- Classically a lucid interval
- Good outcome if treated !
What is an epidural haematoma?
In epidural space, commonly see in contracoup movement (brain hitting inside of skull)
What is subdural haematoma ?
Subdural haematoma;
- common
- complicates 20-30% of head injuries
- rupture of the veins travelling from the brain surface to the saggital sinus
- Prognosis worse
What is subarachnoid haemorrhage ?
Subarachnoid haemorrhage;
- associated with ruptured berry aneurysm
- more commonly caused by head injury
What is scalp haematoma?
See image
Also be suspicious of intracranial pressure and if something going on underneath
What is intracerebral haemorrhage ?
Intracerebral haemorrhage;
- Stretching and shearing injury
- Impact on inside of skull
- Often contrrecoup injury
Can be diffuse and also happen with shaken baby syndrome as well as traffic accidents
