Overview #
This guideline focuses on the assessment and initial management of a decreased level of consciousness (i.e. alertness), as measured by the GCS or AVPU scale. Acute confusion (i.e. impaired mental processes or thoughts) is covered in the Delirium guideline. Note that patients may experience one or both of altered cognition or conscious state.
- GCS
- [MD Calc – Glasgow Coma Scale/Score (GCS)]
- NB: The GCS is only validated to assess the level of consciousness of patients with acute brain injury.
- AVPU
- Alert
- Responds to voice
- Responds to pain
- Unresponsive
Triage #
Immediately see a patient with an acute change in conscious state and initiate a MET call as per local protocols.
A GCS of 8 or less or P on the AVPU scale is potentially life-threatening and requires urgent assessment and support of the airway, breathing and circulation if a rapidly reversible cause cannot be identified and addressed.
Causes #
Urgent causes to consider
- Hypotension
- Hypovolaemia (e.g. acute blood loss)
- Sepsis
- Medication toxicity
- Neurological
- Stroke
- Intracerebral bleed
- Subarachnoid haemorrhage
- Ischaemic stroke
- CNS trauma
- Epidural haematoma
- Subdural haematoma
- Seizures/post-ictal state
- Hypertensive encephalopathy
- Cerebral vasculitis
- Stroke
- Infection
- Sepsis
- CNS infection [BMJ]
- Bacterial meningitis
- Encephalitis
- Organ failure
- Respiratory failure
- Hypoxia
- Hypercapnia
- Cardiac failure
- Hypoxia
- Hepatic encephalopathy
- Uraemic encephalopathy
- Respiratory failure
- Metabolic
- Hypo/hyperglycaemia
- Hypo/hypernatraemia
- Hypercalcaemia
- Drugs
- Opioid or sedative toxicity
- Alcohol withdrawal/delirium tremens
- Psychotropic medications
- Endocrine
- Hypothyroid (myxoedema coma)
- Addisonian crisis
Clinical features #
History from patient, collateral from relatives/ward staff
- What is the acute change in conscious state? What is the patient’s baseline and how rapidly has it changed?
- GCS, AVPU
- Is the patient also acutely confused, and in what way?
- Precipitating event (e.g. fall, seizure, recent febrile illness)
- Previous episodes of altered conscious state
- Goals of care
Chart review
- Medical history
- Comorbidities
- Recent surgery (residual anaesthetic/analgesia, fluid/electrolyte disturbance, infection), procedures or treatments
- Medications
- Recent change (newly prescribed, stopped/omitted)
- Herbal remedies, non-prescription drugs, illicit drugs/alcohol [BMJ]
- Potential drug interactions
- Impaired gut/renal/hepatic function causing abnormal doses
Examination
- General appearance
- Pallor, cyanosis
- Fluid status
- Bruising/bleeding
- GCS, alertness, orientation
- Vital signs
- Neurological
- Pupil size and symmetry (drug intoxication/withdrawal, stroke, brainstem pathology [BMJ])
- Subtle facial or ocular twitching (ongoing seizure activity)
- Neck stiffness, photophobia (meningitis, SAH)
- Tone, reflexes
- Lateralising signs (stroke, intracranial space occupying lesion)
- Observe for facial droop, tongue deviation limb posture, spontaneous limb movement
- HEENT
- Signs of head trauma – palpate skull and neck, haemotympanum (base of skull fracture)
- Bitten tongue (seizure)
- Chest
- Localising signs of infection i.e. crackles, dullness to percussion
- Increased work of breathing
- Abdo
- Localising signs of infection i.e. tenderness on palpation, rebound tenderness, guarding, rigidity
- Signs of decompensated liver failure (jaundice, ascites, bruising)
- Other
- Check for wounds/dressings/drain tubes/ports etc. for potential sources of volume loss or sepsis
Investigations #
| Initial | |
| Bedside | BSLECG Urinalysis (as part of septic screen) |
| Pathology | FBE UEC LFT CMP CRP ABG/VBG (O2, CO2, lactate)Blood and urine cultures (as part of septic screen) |
| Imaging | CT brain (if suspected acute neurological cause)CXR (as part of septic screen) |
| Other | LP (if suspected meningitis/encephalitis/SAH after clear CTB) |
| Further | |
| Cardiac | Troponins, BNP, echo, holter/stress test, coronary angiography |
| Respiratory | CTPA, V/Q scan |
| Neurological | MRI brain, EEG (if non-convulsive status epilepticus considered) |
| Autoimmune | ANA, RF, ESR, C3, C4 |
| Endocrine | TFT, Serum cortisol levels |
| Drugs | Drug levels, alcohol level |
Management #
For acutely deteriorating patients, management should be initiated during the initial assessment.
Involve a senior clinician early.
| General early management |
| Initiate a MET callStabilise ABCSpinal immobilisation (if potential head trauma)Airway support and supplemental O2 as requiredIV access If hypotensive/shocked: rapid IV fluid resuscitation Take bloods during this stepMonitoring – pulse oximetry, ECG, BP |
| Diagnose and treat specific underlying cause and prevent secondary brain injury |
| Specific early management | |
| Neurological | |
| Intracerebral bleed | Reverse bleeding diasthesisIf coagulation factor deficiency or severe thrombocytopaenia – factor replacement therapy or plateletsIf on warfarin or NOAC – consult haematologyRefer to neurosurgery |
| Subarachnoid haemorrhage | Refer to neurosurgery |
| Epidural/subdural haematoma | Avoid hypoxaemia and hypotension (prevent secondary brain injury)Early CT scanIf moderate head injury (GCS 9-13)Period of clinical observationEarly neurosurgical consult If severe head injury (GCS 3-8)Early intubationEarly neurosurgical consultConsider use of anticonvulsantsConsider ICP monitoringICU admissionIf clinical/CT evidence of raised ICP/mass effect consult with neurosurgery re:Short term hyperventilation to PaCO2 30-35Bolus of mannitol (1 g/kg)Prophylactic anticonvulsants |
| Infection | |
| Sepsis | |
| Bacterial meningitis | Ceftriaxone 2 g IV 12-hourly OR cefotaxime 2 g IV 6-hourlyDexamethasone 10 mg IV, start before or with the first dose of antibiotic, then 6-hourly for 4 daysIf severe penicillin hypersensitivity:Moxifloxacin 400 mg IV dailyListeria cover (age > 50, immunocompromised, pregnant, Hx alcohol misuse):ADD Benzylpenicillin 2.4 g IV 4-hourlyIf penicillin hypersensitivity:Trimethoprim+sulfamethoxazole 5+25 mg/kg up to 480+2400 mg IV 8-hourlyStrep pneumoniae cover (Gram positive diploccoci on Gram stain, pneumococcal antigen assay of CSF positive, known or suspect otitis media or sinusitis, recent treatment with beta-lactam antibiotic):Vancomycin 25-30 mg/kg IV as loading dose |
| Encephalitis | Acyclovir 10 mg/kg IV 8-hourlyListeria cover if indicated |
| Hypotension | Hypotension – Teaching for Impact |
| Hypo/hyperglycaemia | If patient is alcohol dependent or appears malnourished, administer thiamine 100 mg IV before glucose to prevent Wernicke encephalopathy |
| Opioid or sedative toxicity | If SpO2 < 92%, manage hypoventilation with naloxone:Naloxone 0.04 to 0.2 mg IV, every 2-3 minutes according to clinical effect up to a maximum total initial dose of 10 mgAdequate reversal indicated by increased respiratory drive RR normalisedSpO2 > 92 % on RAImproved level of consciousness sufficient for patient to maintain airway (easily rousable)If no IV access:Naloxone 0.4 to 2 mg IM (depending on the preparation and local protocols). (A dose of 0.8 mg IM is the most appropriate to achieve adequate respiration, reverse coma and avoid the need for repeat doses)OR Naloxone 1.8 mg/0.1 mL nasal spray, 1 spray (1.8 mg) into one nostrilIf QT interval prolongation (risk of torsades de pointes):Continuous ECG monitoring, serial 12-lead ECGs |
References #
- eTG complete [internet]. Melbourne (Vic): Therapeutic Guidelines Ltd; 2019. Opioid poisoning: general management [cited 2021 Aug 28]. Available from
- eTG complete [internet]. Melbourne (Vic): Therapeutic Guidelines Ltd; 2019. Meningitis [cited 2021 Aug 28]. Available from:
- eTG complete [internet]. Melbourne (Vic): Therapeutic Guidelines Ltd; 2019. Encephalitis [cited 2021 Aug 28]. Available from:
- eTG complete [internet]. Melbourne (Vic): Therapeutic Guidelines Ltd; 2019. Stroke and transient ischaemic attack [cited 2021 Aug 28]. Available from:
- Cadogan M, Brown A, Celenza A. Marshall & Ruedy’s On Call Principles & Protocols. 2nd ed. Chatswood: Elsevier Australia; 2011.
- NSW Ministry of Health. Initial Management of Closed Head Injury in Adults (2nd edition); NSW Ministry of Health; 2011 November.
- BMJ Best Practice. Assessment of altered mental status.
Contributors
Reviewing Consultant/Senior Registrar
Dr Janelle San Juan and Dr Luke Foley
Dr Paula Loveland
