head injury Flashcards
what are the types of head injury
pathophysiology
Primary brain injury may be
focal (contusion/ haematoma)
or
diffuse (diffuse axonal injury)
Diffuse axonal injury occurs as a result of mechanical shearing following deceleration, causing disruption and tearing of axons
Intra-cranial haematomas can be extradural, subdural or intracerebral, while contusions may occur adjacent to (coup) or contralateral (contre-coup) to the side of impact
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Secondary brain injury occurs when cerebral oedema, ischaemia, infection, tonsillar or tentorial herniation exacerbates the original injury. The normal cerebral auto regulatory processes are disrupted following trauma rendering the brain more susceptible to blood flow changes and hypoxia
The Cushings reflex (hypertension and bradycardia) often occurs late and is usually a pre terminal event
aims of head injury mx
= is directed towards preventing the secondary causes of brain damage.
There is a set plan for the management of head injuries:
- observation of normal ATLS protocols
- assessment of severity of injury
- assessment of need for skull x-ray
- assessment of need for admission
- assessment of need for neurological consultation
- management of consequences of injury
Additional factors that must be borne in mind in the management are alcohol intoxication, diabetes, MI, strokes and epilepsy.
immediate mx in 1ry care
History from patient, parent or witness - note:
- loss of consciousness
- amnesia
- any neurological symptoms
Examination:
- site of injury, level of consciousness, pupils and co-ordination
- reassures patient or parents of no significant injury
- examination may not be needed to make clinical decision
Give head injury advice.
In significant injury:
do not move patient until neck is properly stabilisedpatients who have sustained a head injury and present with any of the following risk factors should have full cervical spine immobilisation attempted unless other factors prevent this:
- GCS less than 15 on initial assessment by the healthcare professional
- neck pain or tenderness
- focal neurological deficit
- paraesthesia in the extremities
- any other clinical suspicion of cervical spine injury
cervical spine immobilisation should be maintained until full risk assessment including clinical assessment (and imaging if deemed necessary) indicates it is safe to remove the immobilisation device
maintain airway
attend to other significant injuries
pain should be managed effectively because it can lead to a rise in intracranial pressure (1). Reassurance and splintage of limb fractures are helpful; catheterisation of a full bladder will reduce irritabilitywith respect to emergency department assessment
significant pain should be treated with small doses of intravenous opioids titrated against clinical response and baseline cardiorespiratory measurements (1)
make baseline record for A/E staff: history of injury, symptoms, pulse, BP, level of consciousness(description), pupils, limb co-ordination and any observed changes
Patient Advice:
A doctor or nurse practitioner has examined you and considers you fit to go home. However, for the first 24 hours at home you should have a responsible adult with you who has read this information sheet. Most head injuries do not lead to serious complications. However, if you experience any of the following symptoms, you should go immediately to the nearest hospital which has an emergency department.
- severe or increasing headache
- vomiting
- confusion or drowsiness
- fits (collapsing or passing out suddenly)
- any visual disturbance
- dizziness or lack of co-ordination
- weakness in one or both arms or legs
- clear fluid or blood coming out of your ears or nose
- new deafness in one or both ears
- unusual irritability in babies or infants
What you should not worry about It is normal after a head injury to experience the following symptoms over the next few days. These symptoms should disappear over the following two weeks.
- Mild headache. It is safe to take a painkiller such as paracetamol. (Please see the instructions on the packet for advice about how much to take and how often.)
- Feeling sick (without vomiting) or decreased appetite. Avoid alcohol and drink clear fluids whilst symptoms persist.
- Difficulty concentrating
- Increased tiredness which might make you irritable or anxious
- However if you are concerned about any of these symptoms then you should see your doctor.
General Advice
If you follow this advice you should get better more quickly and it may relieve some of your symptoms.
- Rest for at least three days
- Try to avoid stressful situations as these can make any symptoms worse.
- Do not return to your normal school, college or work activity until you feel you have completely recovered.
- You should not drive a motor vehicle or operate machinery for at least 24 hours after your accident.
- Do not work on a computer or play computer games until you have completely recovered.
- Alcohol tolerance is reduced after a head injury so you should not drink alcohol until you are completely recovered
- Do not play any contact sports (for example rugby or football) for at least 3 weeks without talking to your doctor first.
Long-term problems
Most patients recover quickly from their accident and experience no long-term problems. However, if you:
- are still experiencing problems two weeks after your accident
- are concerned as to whether you are fit to drive a car or motorbike
- develop new problems after a few weeks or months
please contact your doctor as soon as possible so that they can make sure you are recovering properly
initial mx 2ry care
- 1O Survey
-
A: intubation, immobilise C-spine
- When to ventilate:
· GCS ≤ 8
· PaO2 <9KPa on air / <13KPa on O2 or PCO2 >6KPa
· Spontaneous hyperventilation: PCO2 <3.5KPa
· Respiratory irregularity
- B: 100% O2 – if O2 sats<92% or hypoxic in ABG, RR
- C: stop blood loss, IV access – Tx shock, BP, HR
- D: GCS, pupils (check every 15min)
-
Treat seizures
- Lorazepam 2-4mg IV
- Phenytoin18mg/kg IVI then 100mg/6-8h
- E: expose pt. and rapid examination
- Investigations
- Neurological examination
- Hx if possible
- How and when?
- GCS and other vitals immediately after injury
- Headache, fits, local neuro signs, LOC, vomiting, amnesia – retrograde/anterograde, EtOH
- 2O Survey
-
Look for:
- Lacerations
- Obvious facial/skull deformity
- CSF leak from nose (rhinorrhoea) or ears (otorrhoea)
- Blood behind TM
- Battle’s sign, Racoon eyes
- Palpate posteriorly - C-spine tenderness ± deformity
- Neurosurgical opinion if signs of ↑ICP, CT evidence of intracranial bleed significant skull #
- Admit if:
- Difficult to assess: child; post-ictal; alcohol intoxication
- N.B blood alcohol of <44mmol/L unlikely to cause coma – can estimate from the osmolar gap blood alcohol ≈ 40mmol/L, osmolar gap ≈ 40mmol/L
- fracture
- CNS signs: vomiting, severe headache
- N.B Brief loss of consciousness does not require admission if well and a responsible adult is in attendance
- Neuro-obs half-hrly until GCS 15
- GCS, Pupils
- HR, BP
- RR, SpO2
Temperature
ix
CT
CT head immediately
- GCS < 13 on initial assessment
- GCS < 15 at 2 hours post-injury
- 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
CT head scan within 8 hours of the head injury - for adults with any of the following risk factors who have experienced some loss of consciousness or amnesia since the injury:
- age 65 years or older
- any history of bleeding or clotting disorders
- dangerous mechanism of injury (a pedestrian or cyclist struck by a motor vehicle, an occupant ejected from a motor vehicle or a fall from a height of greater than 1 metre or 5 stairs)
- more than 30 minutes’ retrograde amnesia of events immediately before the head injury
If a patient is on warfarin who have sustained a head injury with no other indications for a CT head scan, perform a CT head scan within 8 hours of the injury.
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Criteria for immediate request for CT scan of the head (children)
* Loss of consciousness lasting more than 5 minutes (witnessed)
* Amnesia (antegrade or retrograde) lasting more than 5 minutes
* Abnormal drowsiness
* Three or more discrete episodes of vomiting
* Clinical suspicion of non-accidental injury
* Post-traumatic seizure but no history of epilepsy
* GCS less than 14, or for a baby under 1 year GCS (paediatric) less than 15, on assessment in the emergency department
* Suspicion of open or depressed skull injury or tense fontanelle
* Any sign of basal skull fracture (haemotympanum, panda’ eyes, cerebrospinal fluid leakage from the ear or nose, Battle’s sign)
* Focal neurological deficit
* If under 1 year, presence of bruise, swelling or laceration of more than 5 cm on the head
* Dangerous mechanism of injury (high-speed road traffic accident either as pedestrian, cyclist or vehicle occupant, fall from a height of greater than 3 m, high-speed injury from a projectile or an object)
- Bloods: FBC, U+E, glucose, clotting, EtOH level, ABG
Criteria for head injury referral to a hospital emergency department
by community health services e.g. general practice and NHS minor injury clinics
- GCS less than 15 on initial assessment
- any loss of consciousness as a result of the injury.
- any focal neurological deficit since the injury (examples include problems understanding, speaking, reading or writing; decreased sensation; loss of balance; general weakness; visual changes; abnormal reflexes; and problems walking)
- any suspicion of a skull fracture or penetrating head injury since the injury (for example, clear fluid running from the ears or nose, black eye with no associated damage around the eyes, bleeding from one or both ears, new deafness in one or both ears, bruising behind one or both ears, penetrating injury signs, visible trauma to the scalp or skull of concern to the professional)
- amnesia for events before or after the injury. The assessment of amnesia will not be possible in pre-verbal children and is unlikely to be possible in any child aged under 5 years
- persistent headache since the injury
- any vomiting episodes since the injury
- any seizure since the injury
- any previous cranial neurosurgical interventions
- a high-energy head injury (for example, pedestrian struck by motor vehicle, occupant ejected from motor vehicle, fall from a height of greater than 1 m or more than five stairs, diving accident, high-speed motor vehicle collision, rollover motor accident, accident involving motorized recreational vehicles, bicycle collision, or any other potentially high-energy mechanism)
- history of bleeding or clotting disorder
- current anticoagulant therapy such as warfarin
- current drug or alcohol intoxication
- age 65 years or older
- suspicion of non-accidental injury
- continuing concern by the professional about the diagnosis
If absence of any the factors listed, the professional should consider referral to an emergency department if any of the following factors are present depending on their own judgement of severity:
- irritability or altered behaviour, particularly in infants and young children (that is, aged under 5 years)
- visible trauma to the head not covered above but still of concern to the professional
- adverse social factors (for example, no one able to supervise the injured person at home)
- continuing concern by the injured person or their carer about the diagnosis
The most important points to assess in a head injury are:
- history of events preceding and following the injury
- external evidence of injury
- basal skull fracture
- conscious level - Glasgow Coma Scale or equivalent
- pupillary abnormalities - cranial nerves II and III
- limb movements - hemiparesis or hemiplegia may occur, either contralateral or ipsilateral to the side of the lesion, but are of little value in localising the site of the damage.
These guide the need for further investigation and provide a baseline from which to assess progress.
criteria for performing a skull radiograph
Until recently, about 80% of patients attending Accident and Emergency departments with head injury received a skull X-ray. In order to reduce the number of films taken, the Royal College of Radiologists have devised a set of guidelines which have been shown to halve the number of radiographs taken yet still detect 94% of fractures.
An X-ray is recommended if any of the following are present:
- suspected penetrating injury or scalp bruising or swelling
- loss or alteration of consciousness at any time (some centres require that the loss of consciousness be for longer than 5 min)
- CSF or blood from the nose or ear
- focal neurological symptoms or signs
- alcohol intoxication - but poor co-operation may impair quality of X-ray
- patient lives alone
- presence of other neurological illness which may confuse clinical interpretation, e.g. stroke
- circumstances are suggestive of a particularly forceful impact
Note however that NICE now recommend that “..current primary investigation of choice for the detection of acute clinically important brain injuries is CT imaging of the head……Plain X-rays of the skull should not be used to diagnose significant brain injury without prior discussion with a neuroscience unit. However, they are useful as part of the skeletal survey in children presenting with suspected non-accidental injury..”
referral to a neuroscience unit
skull fracture plus any of:
- confusion or worse impairment of consciousness
- one or more seizures
- neurological signs
- deterioration in level of consciousness
- coma persists after resuscitation } even if no fracture
- confusion or other neurological disturbance of more than 8 hours duration } even if no fracture
- depressed fracture of skull vault
- suspected fracture of skull base
other aspects of medical care of head injuries
- Seek expert advice.
- Nutrition must be continued with due reference to any fasting for surgery. About 2000-3000 KCal/day should be provided through a nasogastric tube.
- General nursing is essential - frequent turning is necessary to prevent bed sores; the eyelids should be taped to prevent damage to the cornea; the limbs should be passively exercised to prevent the development of contractures; pain may be relieved by codeine phosphate.
- “Stress ulceration” may result in the development of gastrointestinal bleeding
- there is a lack of concensus regarding pharmacological management to prevent ‘stress ulceration’
- H2 antagonists such as cimetidine or ranitidine are often prescribed but they seldom prevent ulceration, presumably because of the role of mechanisms other than gastric acidity in these circumstances.
- proton pump inhibitors and sucralfate have been used
- Pyrexia is common. Frequently, it is the result of infection, either intracranially, in the chest or in the urinary tract. It may persist in the absence of infection, presumably, as a result of damage to the hypothalamus. In such cases, fans should be used to cool the patient, and chlorpromazine may be useful.
- Seizures occur in about 5% of patients and are a powerful predictor of post-traumatic epilepsy. They can usually be controlled with phenytoin.
risks of intracranial haematoma
depending on presence/absence of skull fracture + degree of consciousness
- Fully conscious, no skull # = <1:1000
- Confused, no skull # = 1:100
- Fully conscious, skull # = 1:30
- Confused, skull # = 1:4
basal skull fracture s/s
Clinical features may suggest a basal skull fracture even in the absence of a positive skull x-ray.
Evidence of anterior fossa fracture:
CSF rhinorrhoea:
- due to damage to the cribriform plate
- this often requires formal dural repair
bilateral periorbital haematoma:
- bruising limited to the orbital margins indicates blood tracking from behind
subconjunctival haemorrhage where the posterior margin cannot be seen
Evidence of petrous temporal fracture:
- bleeding from the external auditory meatus
CSF otorrhoea:
- through a torn tympanic membrane
- usually a linear injury which does not require formal dural repair
Battle’s sign:
- bruising over the mastoid
- may take 24-48 hr to develop
A basal skull fracture provides a route for infection. Antibiotics are given to prevent meningitis; the course lasts at least seven days, or if there is a CSF leak, until seven days after this has ceased.
GCS
he Glasgow coma scale measures 3 different types of response. These are:
- best motor response - 6 grades
- best verbal response - 5 grades
- eye opening - 4 grades
An overall score is made by summing the score in the 3 assessed areas. The lowest possible score is 3. The maximum is 15.
Generally in managing patients, a score of 8 is felt to be the threshold - less than 8 implies a significant problem.
Notes (1):
monitoring and exchange of information about individual patients should be based on the three separate responses on the Glasgow Coma Scale (for example, a patient scoring 13 based on scores of 4 on eye-opening, 4 on verbal response and 5 on motor response should be communicated as E4, V4, M5)
if a total score is recorded or communicated, it should be based on a sum of 15, and to avoid confusion this denominator should be specified (for example, 13/15)
individual components of the GCS should be described in all communications and every note and should always accompany the total score
the paediatric version of the Glasgow Coma Scale should include a ‘grimace’ alternative to the verbal score to facilitate scoring in pre-verbal children
