Rationale
Coma is a state of prolonged and pathologic unconsciousness. It may be defined as a score of 8 or less on the Glasgow Coma Scale. Coma is a medical emergency and requires urgent evaluation to avoid permanent brain injury or death.
Causal Conditions
(list not exhaustive)
- Focal disease
- Space-occupying lesion (e.g., tumour, abscess)
- Stroke (e.g., brainstem infarction)
- Trauma
- Diffuse disease
- Vascular (e.g., hypertensive encephalopathy, eclampsia)
- Infectious (e.g., meningitis, encephalitis)
- Metabolic (e.g., uremia, hypercalcemia, hypoglycemia)
- Toxins (e.g., lead, carbon monoxide, alcohol, opioids)
- Seizures (including postictal state)
- Diffuse ischemia (e.g., shock)
- Trauma
Key Objectives
Given a patient in coma, the candidate will diagnose the cause, severity, and complications, and will initiate an appropriate management plan.
Enabling Objectives
Given a patient in coma, the candidate will
- list and interpret critical clinical findings, including those derived from
- a complete history and corroboration of information from appropriate sources;
- the identification of most likely causes of coma by means of a complete physical examination including appropriate neurologic examination; and
- the determination of level of consciousness using an appropriate assessment tool (e.g., Glasgow Coma Scale);
- list and interpret critical investigations, including laboratory investigations (e.g., toxin screen, glucose), diagnostic imaging (e.g., computed tomography, magnetic resonance imaging), and others (e.g., lumbar puncture, electroencephalography); and
- construct an effective initial management plan, including
- initiating immediate and emergent care (e.g., airway, breathing, circulation) and appropriate empiric treatment as indicated (e.g., narcotic/benzodiazepine reversal, glucose);
- initiating other urgent treatment as indicated (e.g., antibiotics, anticonvulsants);
- referring the patient for specialized care (e.g., neurosurgery) if necessary; and
- seeking clarification of proxy decision-making while the patient is incapacitated.