Author: Josh Bickley / Editor: Charlotte Davies / Codes: CAP18, CMP3, HAP22 / Published: 31/07/2018
Head Injury In Adults
Patients with head injuries are the most common type of trauma seen in the Emergency Department and can represent up to 10% of all presentations.
Most of these are minor and can safely be discharged but missing serious pathology can have major implications. It is important, therefore, to be able to recognise the red flag features and instigate appropriate investigations, management and specialist referral early. Possibly the biggest pitfall in managing these patients is to dismiss people as simply intoxicated. Drug and alcohol intoxication increases the risk of significant head injury and can have similar clinical features. There have been countless examples of missed intracerebral bleeds that led to potentially avoidable poor outcomes. In a combative, drunk patient with a head injury think bleed!
The primary investigation for suspected traumatic brain injury and skull fracture is a non-contrast CT head and your history and examination should be focussed towards features that would lead you to perform a scan. All emergency departments should have round the clock access to this investigation and accompanying report from a radiologist. There is no indication for plain film radiograph (x-ray) of the skull (in adults) to assess for skull fracture.
Your exam must include GCS, pupils and degree of limb movement as well as an assessment of wounds on the head including any evidence of a base of skull fracture (see NICE guidelines).
The NICE guidelines are fairly clear on which adults with head trauma should receive a CT head, and also give a time frame in which it should be performed. If you ever get stuck these are a good reference point. There are also RCEM standards (currently under review) that offer guidance about the patient”s suitability for a scan, and how quickly they should be assessed. They suggest patients should receive written head injury advice and reattenders should be seen by a senior clinician. They also suggest that if GCS < 15 observations should be recorded every 30 minutes until the GCS is 15 (tricky for confused patients). Once admitted, patients should have observations half-hourly for 2 hours, then 1 hourly for 4 hours, then 2 hourly thereafter.
Sam Birks (@BirksMD) April 5, 2018
FROM ST EMLYNS SITE
People on warfarin or other anticoagulants who attend an emergency department after a head injury should have a CT scan within 8 hours regardless of other risk factors (unless meeting criteria for an earlier scan). Interestingly, the NICE guidelines don’t specify that patients on DOACS should have a scan, simply because there wasn’t enough evidence at the time of recommendation not because they shouldn’t be scanned!! The AHEAD study is a trial looking at the rates of bleeds in warfarinised patients.It’s worth a read and make sure you appraise it yourself!
It’s worth noting that there are a very small proportion of patients who will bleed later, and even with a normal scan safety netting is important.
In many places, although CT reports are quick, they’re at least 10 minutes after the scan was performed. It pays to be able to interpret them, neurosurgery may have accepted your patient by the time the scan is reported! Haemorrhage on CT differs in appearance depending on the location of the bleeding.
The most common traumatic bleeds are subdural (usually slower bleeding from bridging veins in the subdural space, typically in older patients) and extradural haematomas (arterial bleed that appears lentiform in shape as the blood is unable to cross the tight adhesions of the dura mater to the skull.) Other types of bleeding include cerebral contusions in the parenchyma that can cause significant mass effect and diffuse axonal injury that is associated with poor prognosis. Always wait for a formal report before sending a patient home after a CT scan. Subarachnoid bleeding may be traumatic in origin but may also precede trauma due to reduced consciousness.
Primary or Secondary Brain Injury?
Primary brain injury is the damage caused to brain tissue from the initial force applied to the brain, which clinicians can’t prevent. The aim in the management of patients with major head injuries is generally to prevent secondary brain injury. Secondary injury occurs in the hours to weeks following a primary injury, and is caused by many different structural and chemical changes that lead to further destruction of brain tissue.
The most important contributors to secondary brain injury are cerebral oedema, expanding haematoma, hypoxia and hypotension. Depending on local guidance, you will find that most intracranial bleeds should be discussed with neurosurgery, as should base of skull fractures and depressed skull fractures.
More worrying features are signs of raised intracranial pressure on CT or reducing GCS. Neurosurgery can often prevent secondary injury by preventing further haematoma expansion (and therefore further oedema and raised intracranial pressure). It’s imperative in the emergency department that patients are resuscitated aggressively to prevent prolonged hypoxia and hypotension which causes further brain ischaemia. Patients who have intracerebral bleeding on anticoagulants should have this reversed with vitamin K and either octaplex/FFP depending on haematologist advice. Traditional advice is to avoid nasopharyngeal airways and nasogastric tubes in any patient suspected of a base of skull fracture. Many pre-hospital services now would put in NPs.
In people who do not meet the criteria for CT scan there may be other factors to consider, such as wounds that need to be addressed and those who you suspect may have a facial fracture. Consider orbital fractures in patients with injuries around the eye, especially if they have diplopia. Assess the orbit for symmetry and bony tenderness, eye movements, pupils and visual acuity. Imaging options include X-ray and CT of the facial bones.
It’s easy to miss other injuries, especially in those with a reduced GCS that may not be able to give a good history, and a thorough secondary survey is often required. Remember the head is attached to the neck so do a good assessment of the cervical spine and in cases where this is not possible due to reduced GCS or major distracting injury it is important to immobilise the C-spine and perform imaging.
Patients should only be discharged if they have a safe place to go and a responsible (sober) adult who can watch them to ensure they don’t deteriorate. Most departments have advice leaflets for patients being discharged and its particularly important to warn about vomiting or increasing drowsiness. If a patient can’t get anyone to keep a close eye on them then they need to stay in hospital for observation after the injury until you are satisfied they are safe to go home. This is usually in the observation unit of the emergency department.
What if it’s a minor Head Injury?>
Most of the adults you see with head injuries won’t need a CT scan. Many will have symptoms that don’t need a scan, but they’ll be very worried. Some may even have concussion.
Post-concussive syndrome is a well recognised, highly variable collection of symptoms that generally involves a headache and difficulty in concentration. Dizziness is a common feature. It’s discussed well on the RCEM learning podcast and the BMJ has a great infographic. Concussion can last for several weeks and can be very disabling and anxiety inducing.
Second impact syndrome can occur when a patient with post concussion syndrome receives a further head injury the second trauma can lead to herniation and death. It is important to warn patients about this following a head injury, (particularly those who play contact sports) to have a gradual return to play after a period of rest, and get some brain rest, drink plenty of fluids and avoid the alcoholic kind! If your patient wishes to return to playing sport, check out their organisation’s rules, RFA and MSA.