Adult Head Injury
Introduction.
Every year in England and wales 1.4 million people attend A+E with a head injury, this makes up just over 6.5% of the presentations that Emergency departments see with 20% of them being admitted. [1]
Ultimately, 90% of people end up being diagnosed with a minor head injury and are discharged, however making that decision can sometimes be tricky [1]
Ambulance staff often have a difficult time managing head injuries. We are without the luxury of imaging equipment and often lacking the option to take a watch and wait approach with patients, often having the make a decision of what to do with a patient based on a 20 to 30 minute assessment in environments and situations that are not always conducive to medical assessment.
This week we’re tackling the assessment of Adult head injuries, we’ll go through some red flags to be aware of as well as how to appropriately safety net our patients.
So, lets get started.
The History:
Ask about the the Mechanism involved with sustaining the headinjury.
What did they hit their head on? Did they hit the object or did the object hit them?
• Fall from a height of greater than 1 metre or 5 stairs.
• High-speed motor vehicle collision either as a pedestrian, cyclist, or vehicle occupant.
• Rollover motor accident or ejection from a motor vehicle.
• Accident involving motorized recreational vehicles or bicycle collision.
• Diving accident.
These are considered concerning mechanisms because not only do they increase the likelyhood of a brain injury because if the high forces involved, but also because they present the risk of unstable spinal fractures. [2] [3]
Recalling the Event
Can the patient remember the event? events before and after? If not, we need to consider why and if this represents a loss of conciousness prior to the head injury or as a result of it.
Loss of conciousness prior to the headinjury could be due to a multitude of factors. Listen to our T-LOC podcast to examine some possible causes.
Losing conciousness as a result of a headinjury is a redflag as this is indicative that it is no longer a simple headinjury, but that the brain has been insulted in some form or another. This could be a simple concussion or could be a more sinister cause, either way, the patient needs monitoring and neuro observations in hospital and potentially even a CT scan before being discharged.
How have they been since the event?
Vomiting since incident - This is an important symptom to take note of as it can be concerning to us. As we said in the podcast, our actions differ here slightly between adults and children, but in adult headinjuries NICE guidance would suggest that any head injured adult that has vomited be conveyed to ED for monitoring and further work up. 1 vomit is likely to be observed for a short while, where as multiple vomiting episodes should receive a CT scan. [2] (see 1.1.4 and 1.4.7)
Headache - Generally headaches over or around the point of impact are less concerning, providing no other redflags or concerning features we can see if simple OTC analgesias resolve this. However, persistant or severe generalised headaches, or those that do not resolve with rest and simple analgesia may be concerning and may require assessment in hospital. [2]{ see 1.1.3}
Neck pain - We aren’t going into the assessment of neck pain too much here; only to say that the neck should be assessed thouroughly in head injury. Bare in mind that tools such as the CCR or NEXUS spinal guidelines only help us to exclude clinically relevant unstable neck fractures.
Waxing / waining GCS or Lucid intervals - As discussed in the podcast, this is of particular concern, especially in the young where it is highly associated with epidural bleeds. Up to 1/5 epidural bleeds will present with a lucid interval prior to deterioration [4] often lasting a number of hours [11]. This is due to bleeding, (normally from the middle menigeal artery [11] causing a separation of the duramater from the skull lining allowing bleeding to continue without ICP elevating[10]. A typical history is of a loss of conciousness following the insult, followed by a period of “lucidity”, as the bleed fills up the empty space in the cranium. Once the empty space is filled, ICP begins to increase significantly and conciousness once again drops as the brain begins to herniate [10]. This presentation and indeed Epidural haemorrhages are less common in elderly patients, who due to the decreased elasticity of their tissues, are more likely to have subaracnoid or intraparanchimal bleeds.
Do not be reassured by a lucid interval.
Past medical history
Normal Response level - We need to find out if patients are presenting normally for themselves. In patients who are demented or who have additional learning needs, they may not have a GCS of 15/15 ordinarily, so we need to ensure we are putting our assessment into perspective and comparing the patient against their normal baseline. See the video below around scoring GCS properly.
Recent alcohol or drug intake - Clearly any patinet who is intoxicated or who has taken a mind altering substance cant be assessed accurately as this could mask some underlying neurology caused by the headinjury. Infact being intoxicated with a headinjury is one of the strongest predictors of Traumatic Brain Injury (TBI)[5] . We are also at significant risk of clinical bias towards patients who are intoxicated and passing them off as “just another drunk”. [checkout episode 6 on cognitive bias here] Treat these patients seriously as there are a number of serious incidents each year where clinicians have inappropriately judged these situations and patients have come to harm. Patinets who are intoxicated with headinjuries should be conveyed to ED for monitoring and if needed a CT head.
Alcoholism - Alcohol dependent patients are signficant falls risks and at risk of headinjury. Alcoholism causes cerebral atrophy, increasing the area within the cranial vault for blood to collect (= delayed symptoms) and more space for the brain to move (= higher risk of TBI). Secondly, due to the hepatic injury these patients have derranged clotting factors namely thrombocytopenia (low platelets) and thrombocytopathy (poorly functioning platelets) [6]. They are therfore are at greater risk of intracranial bleeds.
Current anticoagulant medication - Clearly patients who take medication to reduce their clotting will be at increased risk of bleeding. NICE guidance states that any patient on antiCOAGULANTS must have a CT Head [2]. The guidance is less prescriptive for those on antiPLATELETS however and so appropriate decision making must be applied. As discussed in the podcast, the evidence is quite poor eitherway as to the risk for TBI. In our own practice we would opt to take these patients to ED for monitoring.
Bleeding or clotting disorder - NICE guidance is that these patients should go to ED for a CT Head [2] .
Previous neuro surgical interventions - Increased risk of complications, should be conveyed to ED for CT head. [2] [7]
Being intoxicated WITH a headinjury is one ofthe strongest predictors
of Traumatic Brain Injury. Studies suggest that between 30 and 50%
of patients with a TBI were intoxicated at the time of injury. [5]
Physical assessment:
Physical injury - Assessment of the wound itself, being sure to assess depth and need for closure. Wounds stretching into the facial trangle or affecting complicated areas such as the vermillian boarder, may require specialist closure / plastics involvement.
Assessing to ensure the patient is not shocked - hopefully an obvious point, but especially in poly-trauma patients do not forget to consider other areas of bleeding.
Assess for a suspected basal skull fracture- which may present with:
- Clear fluid (possible cerebrospinal fluid) leaking from the ear(s) or nose. Can be diferntiated using a bit of gauze, see Halo sign. [8]
- Periorbital haematoma(s) with no associated damage around the eyes.
- Bleeding from one or both ears; blood behind the ear drum (haemotympanum); new deafness in one or both ears. [9]
- Battle's sign — bruising behind one or both ears over the mastoid process, suggesting fracture of the middle cranial fossa.[9]
Neck assesment - neck tenderness: midline cervical spine tenderness may indicate cervical spine injury.
Range of neck movements — an inability to rotate the neck 45 degrees to the left and right may indicate cervical spine injury. Note: safe examination of the neck
Bare in mind that CCR and Nexus just help to exclude clinically relevant unstable neck fractures. They will not exclude a possible spinous process or laminar fracture, so may still requiring imaging. Use appropriate clinical judgement based on detailed examinations.
Neurological exam
Glascow Coma Score - This is the video simon described in the podcast. Remember this is an objective score, if the patinet is normally GCS 14/15 then that is ok, but we need to document this in our paperwork.
Pupils - Assess the pupils using a pentorch to ensure they are equal, round and reactive to light. You should also assess for consensual movement and accomodation to fully assess cranial nerves II and III. [12].
Remeber a “blown” pupil COULD be as a result of a TBI, however there are a number of reasons for an aniscoria so it must be put into clinical perspective.
Cranial nerves - A gross assessment of the cranial nerves is important to assess for neurological symptoms of headinjury and patients should not be discharged without a normal cranial nerve exam in accordance with NICE guidance [2]. A Guide to Cranial Nerve exams can be found HERE . Clearly we do not carry things such as smelling salts or snellen charts, so some realistic modifications need to be made.
Assess for any focal neurological deficit - such as:
- Problems with visual or speech disturbance, understanding speech, reading or writing.
- Problems with balance or walking.
- Loss of muscle power.
- Paraesthesia in the upper or lower limbs or abnormal reflexes.
Safety netting and Discharge advice
This is one of the most important parts of our patient interaction, because this is how we safely discharge patients and ensure they are caught in our safety net incase they deteriorate or we are wrong in our assessment and diagnosis… and those two things are not mutually exclusive, patients CAN deteriorate without it meaning our initial decisions and actions were wrong. This is why this stage is vital so we need to ensure that we explain to the patient the following:
What we think is wrong and what we expect to happen - Patients need to know what we think is wrong, why we feel staying at home is appropriate and what they should expect to happen. What symptoms should they expect? How long should they still have symptoms for? What can they take for pain? when will they be better? when can they eat, drink, sleep normally? We need to ensure this is covered and documented.
What happens if we are wrong, or what happens if they deteriorate - What redflags and symptoms do they need to be aware of?
When they should seek help - when do they need to call 999? when should they see their GP?
Other features for safety netting:
Call backs and follow ups - These are entirely appropriate additions to our clinincal care and safetynetting package. Calling patients back on a recorded line after a few hours or arranging a time to revisit the patient if needed via control may not be typical actions for emergency ambulance crew, but are all appropriate if you feel they are needed for the patients clinical care.
Head injury specific advice - Its advisable that head injury patients are not left alone for at least 24 hours, additionally patinets should probably have appropriate return to work or return to driving follow ups done by their GP if they have been advised to halt these as a result of a head injury. NICE provide a very useful patient information leaflet, that we can go through with our patients and leave with them. FIND IT HERE. (We would not advise using THIS link for clinical practice, navigate directly via NICE to ensure the most up to date copy).
As always clinicians are responsible for their own practice. These podcasts are produced for informative purposes and should not be considered sufficient to adjust practice. See "The Legal Bit" for more info.
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Table compiled from references on right. List not exhaustive and appropriate clinical judgment should be applied.
References:
1 - https://www.nice.org.uk/guidance/cg176/chapter/Introduction
2 - https://www.nice.org.uk/guidance/cg176/chapter/1-recommendations
3 - https://www.nice.org.uk/guidance/qs166/chapter/Quality-statement-4-Assessment-for-cervical-spine-injury
4 - https://www.ncbi.nlm.nih.gov/books/NBK518982/
5- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6561403/
6 - https://pubs.niaaa.nih.gov/publications/arh21-1/42.pdf (page 46)
7 - Chantal, S. (2007), Emergencies in Primary Care, UK:Oxford Pg 222
8- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3602259/
9- https://www.ncbi.nlm.nih.gov/pubmed/11105835
10 - https://www.amboss.com/us/knowledge/Epidural_hematoma