Initial management of the comatose patient

1. Ensure Airway, Breathing, Circulation

  • Maintain SaO2 >90% and pCO2 <40 mmHg
  • Intubate if GCS ≤8 and pCO2 >45 mmHg
  • Maintain MAP >70 mmHg
  • Monitor ECG

2. Obtain blood samples

  • Electrolytes
  • Arterial blood gas - pH, pO2, pCO2, carboxyhemoglobin
  • Liver function tests
  • Thyroid function tests
  • Adrenal function tests
  • Complete blood count
  • Toxicology screen (blood and urine)
  • Blood and urine cultures
  • If capillary glucose <45 mg/dl (2.5 mmol/L) administer glucose

3. Neurologic assessment

See Neurologic assessment in coma

4. Manage increased ICP

If there is clinical evidence of increased intracranial pressure or herniation, consider ICP-lowering measures:

  • Hyperventilate to target pCO2 25-35 mmHg
  • Administer hyperosmotic agent
    • Either mannitol 0.5-1.0 g/kg
    • Or 30 ml 23.4% NaCl

5. Administer specific treatments

  • Administer IV thiamine 100 mg
  • Maintain glucose >60 mg/dL (3.3 mmol/L)
  • Stop seizures
  • Treat infection
  • Restore acid-base and electrolyte balance
  • If intoxication is suspected, consider gastric lavage, activated charcoal and administration of specific antidote
  • Control agitation
  • Adjust body temperature

Specific antidotes for agents causing delirium and coma


AntidoteIndication
NaloxoneOpioid overdose
FlumazenilBenzodiazepine overdose
PhysostigmineAnticholinergic overdose
FomepizoleMethanol, ethylene glycol
GlucagonTricyclic overdose
HydroxycobalaminCyanide toxicity
OctreotideSulfonylurea hypoglycemia

6. Radiology

  • Head CT
  • Consider cervical spine CT
  • Consider CTA

7. Obtain detailed history and perform systemic examination

8. Consider additional investigations

  • Lumbar puncture
    • Cell count
    • Protein
    • Glucose
    • Lactate
    • Cultures
    • Viral and fungal antibodies, PCR
  • EEG
  • Brain MRI



References