NICE NG232 is one of the most reliably tested guidelines in the FRCEM Final. The exam doesn't ask whether you'd scan someone with a GCS of 6 — it tests the grey areas. The patient with a single vomit. The infant with a 4 cm bruise. The threshold that differs between adults and children. These are the details that separate a pass from a near-miss.
This post covers the specific content from NG232 that comes up in the SBA paper, organised by the sections the exam actually targets.
Immediate CT (within 1 hour):
- GCS ≤12 on initial assessment
- GCS <15 at 2 hours after injury
- Suspected open or depressed skull fracture
- Signs of basal skull fracture (haemotympanum, “panda” eyes, CSF otorrhoea/rhinorrhoea, Battle's sign)
- Post-traumatic seizure
- Focal neurological deficit
- More than 1 episode of vomiting
CT within 8 hours — if loss of consciousness or amnesia since injury, plus any of:
- Age ≥65
- Bleeding or clotting disorder (including anticoagulant use)
- Dangerous mechanism of injury (pedestrian or cyclist struck by vehicle, fall from height >1 metre, high-speed motor vehicle collision)
- More than 30 minutes of retrograde amnesia of events before the injury
Immediate CT (within 1 hour):
- Suspicion of non-accidental injury (NAI)
- GCS <14 (or <15 in children under 1 year)
- Post-traumatic seizure
- Suspected open, depressed, or basal skull fracture
- Focal neurological deficit
- Bruise, swelling, or laceration >5 cm on the head of an infant under 1 year
Risk factors (the crucial >1 factor distinction):
- Loss of consciousness >5 minutes (witnessed)
- Abnormal drowsiness
- 3 or more discrete episodes of vomiting
- Dangerous mechanism (fall >3 metres, high-speed road traffic collision)
- Amnesia (antegrade or retrograde) >5 minutes
If 1 risk factor is present: observe for a minimum of 4 hours from the time of injury, with CT if clinically indicated during observation. If more than 1 risk factor is present: CT is indicated.
The exam exploits the differences between adult and paediatric thresholds. These are the ones that catch people out:
| Criterion | Adults (≥16) | Children (<16) |
|---|---|---|
| Vomiting | >1 episode | ≥3 discrete episodes |
| Fall height (dangerous mechanism) | >1 metre | >3 metres |
| GCS threshold for immediate CT | ≤12 | <14 (or <15 if under 1 year) |
| Loss of consciousness | Any duration (triggers 8-hour pathway) | >5 minutes witnessed (risk factor) |
Criteria for discussion with neurosurgery:
- GCS ≤8, persisting after initial resuscitation
- Unexplained confusion lasting more than 4 hours
- Deteriorating GCS (especially motor component)
- Progressive focal neurological signs
- Seizure without full recovery
- Penetrating injury or CSF leak
- New surgically significant abnormality on imaging
Intubation before transfer: GCS ≤8 is mandatory for intubation and ventilation prior to transfer. Ventilation targets: PaO₂ >13 kPa, PaCO₂ 4.5–5.0 kPa (normocapnia — avoid hyperventilation).
Admission criteria include any patient requiring CT, any new clinically significant CT abnormality, GCS not returned to 15 (regardless of CT result), ongoing concern (vomiting, severe headache), other factors (intoxication, other injuries, safeguarding concerns, CSF leak, inadequate supervision at home).
Note: an isolated linear skull fracture with GCS 15 and no other risk factors does not automatically require admission — but the patient needs clear written head injury advice and a responsible adult to observe them.
Observation frequency schedule:
- Half-hourly observations until GCS reaches 15
- Once GCS is 15: at least hourly for 4 hours
- Then at least 2-hourly thereafter
Deterioration trigger: A sustained drop in GCS of 1 point lasting 30 minutes or more should trigger urgent medical review and consideration of repeat CT.
Hypopituitarism: Can occur after head injury of any severity. May present weeks to months later with fatigue, low blood pressure, and hyponatraemia. Consider screening if the patient has low sodium, unexplained hypotension, or is simply not recovering as expected.
Tranexamic acid (TXA): For adults with GCS ≤12 and no significant extracranial bleeding — 2 g IV within 2 hours of injury. This is off-label use. In children: 15–30 mg/kg (max 2 g).
Intoxication: Never assume altered consciousness is due to intoxication alone. The guideline is explicit — only attribute symptoms to intoxication after traumatic brain injury has been excluded.
Pre-injury cognitive impairment: Use the patient's baseline GCS (or functional equivalent) as the comparator, not 15. A patient with pre-existing dementia whose baseline is 13 has not necessarily deteriorated if their current GCS is 13.
GP letter: A written report should be sent to the patient's GP within 48 hours of attendance, detailing the injury, assessment, and any follow-up required.
Practise head injury SBA questions
Apply these NG232 details to exam-style questions — mapped to the FRCEM Final blueprint with detailed explanations.
Go to Question Bank →Reference:
National Institute for Health and Care Excellence (2023). Head injury: assessment and early management. NICE guideline [NG232]. Available at: nice.org.uk/guidance/ng232