Vital signs

Pupil Size

For education. Check every result.

Anatium is a study resource, not medical advice. Nothing here is a diagnosis, a prescription or a substitute for a clinician who has seen the patient. Check every number against a current local protocol before it touches anyone, and never act on a result you cannot reproduce yourself.

Reference range

Range2 to 5 mm

About

Pupil size and reaction. Asymmetry or a fixed dilated pupil in a head injury is a neurosurgical emergency, and opioids constrict both.

When it is low

Miosis (<2mm): Opioids, pontine lesion, organophosphates, pilocarpine

When it is high

Mydriasis (>5mm): Sympathomimetics, anticholinergics, herniation, death

How it is measured

Check size, equality, reactivity. PERRLA notation. Unequal pupils (anisocoria) may indicate herniation.

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