The Glasgow Coma Scale scores eye opening, verbal response and motor response and runs from 3, unresponsive in all domains, to 15. According to NICE guideline NG232 on head injury, published on 18 May 2023, a score of 8 or less is severe traumatic brain injury and requires early involvement of an appropriately trained clinician for advanced airway management. At the CT1 anaesthetics interview the marks are for reporting the three components, protecting the airway, and knowing what counts as deterioration.
Key takeaways
- Report the three components with the total: a score of 13 is described as E4, V4, M5, and the total is given out of 15
- NICE NG232 grades traumatic brain injury as mild at 13 to 15, moderate at 9 to 12 and severe at 8 or less
- A score of 8 or less means early involvement of a clinician trained in advanced airway management, and intubation before transfer to a neuroscience unit
- A score of 12 or less on arrival, or below 15 at 2 hours after injury, means a CT head within 1 hour in people aged 16 and over
- Once intubated, aim for a PaO2 above 13 kPa, a PaCO2 of 4.5 to 5.0 kPa and a mean arterial pressure of 80 mmHg or more
- A sustained drop of 1 point lasting at least 30 minutes counts as deterioration, and the motor score carries more weight
How do you assess consciousness quickly?
You assess consciousness quickly with ACVPU and properly with the Glasgow Coma Scale. The Resuscitation Council UK describes the rapid initial assessment as whether the patient is alert, newly confused, or responding only to voice or pain, or unresponsive.
At the same step, the guidance asks you to examine the pupils for size, equality and reaction, review the drug chart for reversible causes, and give an antagonist such as naloxone where appropriate.
Measure a bedside glucose in every patient with reduced consciousness. In a peri-arrest patient use a venous or arterial sample, because finger-prick readings can be unreliable when the patient is very unwell.
What exactly is the Glasgow Coma Scale, and how is it reported?
The Glasgow Coma Scale has three domains, eye opening, verbal and motor response, each scored independently and summed to a total from 3 to 15. NICE NG232 describes it as an early assessment of the severity of brain impairment.
The guideline is specific about how it is communicated. Base monitoring and handover on the three separate responses, describe a total of 13 as E4, V4, M5, and always carry the components alongside the total in every record.
Two qualifications matter. The paediatric version uses a grimace alternative to the verbal score for preverbal children, and in dementia, chronic neurological disease or learning disability the pre-injury baseline may itself be below 15.
What do you do in the first few minutes?
In the first few minutes with a patient whose consciousness has fallen you protect the airway, correct the reversible causes and score them properly. NG232 asks for immediate assessment by a trained member of staff whenever the score is below 15.
- Airway: a chin lift or jaw thrust, suction and an oropharyngeal or nasopharyngeal airway, and expert help immediately if obstruction persists
- Breathing and oxygen: reservoir mask at 15 litres per minute in critical illness, then titrated to the target range
- Circulation: blood pressure, access and a fluid challenge if hypotensive, because cerebral hypoperfusion is a cause of reduced consciousness
- Disability: pupils, glucose, drug chart, temperature, and the full Glasgow Coma Scale with its components
- Position: nurse the unconscious patient in the lateral position if the airway is not protected
- History: NG232 asks for the pre-injury baseline score where a chronic condition may lower it
However, the anaesthetic question is always the same one. Is this airway safe for the next thirty minutes, and if not, who is intubating and where.
Which GCS score means you secure the airway?
A Glasgow Coma Scale score of 8 or less is the threshold. NG232 asks for early involvement of an appropriately trained clinician to provide advanced airway management and assist with resuscitation whenever the score is 8 or less.
The guideline also gives four immediate indications for intubation and ventilation: coma, meaning not obeying commands, not speaking and not eye opening; loss of protective laryngeal reflexes; ventilatory insufficiency; and irregular respirations.
Ventilatory insufficiency is defined on gases as hypoxaemia with a PaO2 less than 13 kPa on oxygen, or hypercarbia with a PaCO2 more than 6 kPa. Anyone with a score of 8 or less needing transfer to a neuroscience unit is intubated first.
Which findings mean a CT head within the hour?
In people aged 16 and over with a head injury, NG232 gives seven risk factors that each require a CT head within 1 hour of being identified.
- A Glasgow Coma Scale score of 12 or less on initial assessment in the emergency department
- A score below 15 at 2 hours after the injury
- A suspected open or depressed skull fracture
- Any sign of a basal skull fracture: haemotympanum, panda eyes, cerebrospinal fluid leaking from the ear or nose, or Battle's sign
- A post-traumatic seizure
- A focal neurological deficit
- More than one episode of vomiting
A separate group with loss of consciousness or amnesia gets a CT within 8 hours if they are 65 or over, have a bleeding or clotting disorder, had a dangerous mechanism, or have more than 30 minutes of retrograde amnesia.
What are the ventilation targets once the patient is intubated?
Once a patient with reduced consciousness is intubated, NG232 gives targets rather than ranges to guess at. Aim for a PaO2 above 13 kPa and a PaCO2 of 4.5 to 5.0 kPa.
More aggressive hyperventilation is justified only where there is clinical or radiological evidence of raised intracranial pressure, and the guideline says to increase the inspired oxygen concentration if hyperventilation is used.
Maintain the mean arterial pressure at 80 mmHg or more with fluid and vasopressors as needed, and give appropriate sedation and analgesia with a neuromuscular blocking drug. Those are the numbers that make a transfer safe.
How often are the observations repeated?
Observations in a patient with reduced consciousness after head injury are half-hourly until the Glasgow Coma Scale score reaches 15. NG232 then steps them down in a fixed sequence.
Once the score is 15, the minimum frequency is half-hourly for 2 hours, then hourly for 4 hours, then 2-hourly. Any deterioration after the first 2 hours sends the patient back to half-hourly and restarts the schedule.
The minimum documented set is the score, pupil size and reactivity, limb movements, respiratory rate, heart rate, blood pressure, temperature and oxygen saturation. A score alone is not an observation.
What counts as deterioration, and who do you tell?
Deterioration in NG232 is defined precisely, which is what makes it quotable. Agitation or abnormal behaviour, a sustained drop of 1 point in the score lasting at least 30 minutes, or severe or increasing headache or persistent vomiting all trigger urgent reassessment.
So does any drop of 3 or more points in the eye opening or verbal scores, or 2 or more points in the motor score, and any new or evolving sign such as pupil inequality or asymmetry of limb or facial movement.
A second competent member of staff confirms the change before the supervising doctor is involved, immediately where possible, and if nobody is available the supervising doctor is contacted without it. Confirmed deterioration means considering an immediate CT.
What do the assessors score besides the number?
Beyond the number, the assessors in a reduced consciousness scenario score whether you treat a score as a trend owned by a team rather than a value you read once.
The two-observer rule in NG232 exists because interobserver variability is real. Saying that you would have the nurse who found the change score the patient with you is a human factors point, not a hedge.
Reflective practice is a named domain. A usable example is a patient whose motor score slipped overnight while the total looked stable, and the handover habit you changed so components are always passed on.
Which mistakes cost marks here?
The reduced consciousness mistakes at interview are the ones NG232 was written to prevent, and most of them are about losing information between people.
- Handing over a total alone: the guideline asks for the three components in every communication and record
- Assuming a baseline of 15 in a patient with dementia, chronic neurological disease or learning disability
- Quoting 8 or less as the only airway trigger, when loss of protective laryngeal reflexes, ventilatory insufficiency and irregular respirations are separate indications
- Forgetting the glucose, the pupils and the drug chart before attributing the drop to the brain injury
- Hyperventilating routinely, when the target is a PaCO2 of 4.5 to 5.0 kPa unless raised intracranial pressure is evident
- Not naming an observation schedule, so there is no way of noticing the patient getting worse
How this comes up at the CT1 anaesthetics interview
Reduced consciousness reaches the clinical judgement station as the call an anaesthetist actually gets: a patient on a ward or in the emergency department whose score has fallen, with a decision about the airway. The station is 15 minutes after five minutes of reading, marked out of 50.
Clinical judgement and decision making is scored on the score, the reversible causes and the airway threshold. Reflective practice is scored on handover habits, and working under pressure on how you run a stepwise assessment while arranging a scan and a bed.
The follow-up usually pins you to a decision: intubate now, or scan first, with a patient who is vomiting. anaestheticinterview's bank of 340 questions carries AI-marked spoken practice, so that decision can be rehearsed out loud before it is real.