Synopsis
Stabilise and investigate reduced consciousness systematically, distinguish reversible depression from catastrophic brain injury and understand the tightly governed UK process for diagnosing death using neurological criteria.
- Use ABCDE before neurological taxonomy. Hypoxia, hypercapnia, hypotension and hypoglycaemia can cause or worsen brain injury and must be corrected while history and examination proceed.
- Record the best eye, verbal and motor responses that make up GCS, not only the total. Note intubation, language, hearing, sedation, paralysis, facial injury and baseline disability that limit components.
- Establish exact onset and trajectory from witnesses, ambulance records and digital or medication evidence; ask about trauma, headache, seizure, fever, toxins, diabetes, pregnancy, organ failure and psychiatric risk.
- Inspect pupils, gaze, eye position, motor asymmetry, tone, reflexes, plantar responses, breathing pattern, meningism, rash, temperature and signs of trauma while avoiding repeated painful stimulation.
- Pinpoint pupils and respiratory depression suggest opioid effect but are not diagnostic; unequal or newly fixed pupils may indicate herniation, ocular trauma, drug exposure or pre-existing disease.
- Postictal states usually improve. Persistent failure to recover, subtle twitching, gaze deviation, recurrent episodes or unexplained coma raises non-convulsive status and the need for urgent EEG advice.
- A normal initial CT does not exclude early ischaemia, meningitis, encephalitis, toxic-metabolic disease, non-convulsive seizure or all diffuse axonal injuries.
- Brainstem reflex examination used during resuscitation is not equivalent to formal neurological determination of death; sedatives, neuromuscular blockade and metabolic or temperature confounders must be resolved.
- The 2025 UK Code of Practice is the controlling reference for neurological criteria for death. Testing follows a documented plan, prescribed prerequisites, specified brainstem and apnoea components, and required examiner standards.
- Spinally mediated movement can occur after death has been confirmed using neurological criteria; clinicians should anticipate and explain this possibility without improvising interpretation.
- Communication with family should be staged, clear and separate diagnosis of death from possible donation discussions, using the terminology and support set out in national and local policy.
Key red flags
Falling consciousness with a newly dilated or unreactive pupil, progressive motor asymmetry, abnormal posturing, irregular respiration or Cushing-type physiology raises critical intracranial mass effect and requires immediate airway, neurosurgical and imaging action.
Reduced respiratory rate and tidal volume, impaired consciousness and small pupils with a compatible exposure suggests opioid toxicity. Hypoxia, mixed overdose and intracranial disease must still be considered, and response to naloxone does not end observation.
Fever, headache, photophobia, neck stiffness, rash, seizures, focal findings or behavioural change may indicate meningitis or encephalitis. Classic meningism can be absent in older, immunocompromised or deeply obtunded patients.
Unexplained persistent unresponsiveness, fluctuating cognition, subtle facial or limb twitching, eyelid myoclonia or eye deviation after a seizure or brain injury can represent ongoing electrical seizure and requires urgent EEG-supported assessment.
Symmetric motor findings, asterixis, multifocal myoclonus and fluctuating arousal with organ failure or biochemical disturbance suggests metabolic dysfunction, but new focal signs still mandate structural assessment.
A patient with ventral pontine injury may be conscious but quadriplegic and anarthric, retaining vertical eye movement or blinking. Deliberately test command-following through eye movements before concluding awareness is absent.
Investigation priorities
Identify rapidly reversible hypoglycaemia, ventilatory failure, acid-base disturbance and cardiotoxic or electrolyte effects.
Management branches
A patient is unresponsive or substantially below their documented baseline without an established immediately reversible explanation.
- Call for senior and airway help, use cervical-spine precautions when indicated, support oxygenation, ventilation and circulation, check glucose, gain IV access and treat active convulsive seizure.
- Obtain collateral history and examine GCS components, pupils, gaze, limbs, breathing, temperature, rash and trauma; send focused blood tests, ECG and toxicology samples without delaying urgent CT.
- Treat suspected infection, poisoning, metabolic crisis or intracranial catastrophe through the relevant protocol and repeat neurological findings after each intervention or deterioration.