North Carolina EMT State Practice Exam

What does a small pupil size (PERL) indicate?

1. Narcotic and hypoxia

2. Narcotic and organophosphate

3. Brain injury and high blood pressure

4. Dehydration and cardiac failure

The correct answer is: Narcotic and organophosphate

A small pupil size, often referred to in medical terms as "miosis," can indicate several potential medical conditions. In the context of this question, a small pupil size can primarily be associated with exposure to narcotics and organophosphates. Narcotics, such as opioids, are known to cause constriction of the pupils. This is due to their action on the central nervous system, which affects the pupils by stimulating specific pathways that lead to miosis. Organophosphates, commonly found in certain pesticides, can also lead to small pupils due to their action as acetylcholinesterase inhibitors, resulting in an accumulation of acetylcholine at synapses, which can cause increased stimulation of the parasympathetic nervous system, leading to pupil constriction. Understanding the relationships between pupil size and these substances is critical in emergency medical situations. Recognizing that a patient might have ingested narcotics or been exposed to organophosphates allows first responders to make informed decisions about the necessary interventions and treatments for the patient. The other options present alternative conditions but are not typically associated with small pupil size.