Coma is a state of unarousable unresponsiveness in which the patient does not open the eyes or react purposefully, even to pain. It results from dysfunction of both brain hemispheres or the brainstem, from causes such as stroke, trauma, toxins, low glucose or infection.
Key symptoms
- No eye opening or response to voice or pain
- Abnormal or irregular breathing
- Confusion, headache, seizure or a known overdose beforehand
- Witness reports of trauma, drug use or diabetes
What you find on exam
- Airway, breathing and circulation first
- Glasgow Coma Scale score of 8 or less
- Pupils: size, symmetry and light reaction
- Brainstem reflexes, eye movements and posturing
- Clues: needle marks, breath odor, head injury, neck stiffness, fever
Tests
- Fingerstick glucose right away
- Blood gas, electrolytes, kidney and liver tests, ammonia, toxicology screen
- Noncontrast CT head
- Lumbar puncture if infection is suspected; EEG for nonconvulsive seizures
Treatment basics
- Secure the airway; intubate if needed
- Treat low glucose with IV dextrose, giving thiamine first in at-risk patients
- Naloxone if opioid overdose is possible
- Treat the cause: raised intracranial pressure, seizures, infection, temperature
Red flags
- A dilated, nonreactive pupil (brain herniation)
- Irregular breathing, or rising blood pressure with a slow pulse
- Glasgow Coma Scale of 8 or less with an unprotected airway
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Sources: NASEMSO National Model EMS Clinical Guidelines; NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations. Written by Making Synapses. Making Synapses is not affiliated with these organizations.