ZMIST includes which of the following as a component?

• A. Mechanism of injury
• B. Vital signs
• C. Scene lighting
• D. Medical history

Answer: (A)

ZMIST is a quick framework used during the initial trauma assessment to organize key information about what happened. A central part of it is the mechanism of injury—the way the event occurred. Understanding the mechanism guides you to anticipate injuries that may not be immediately visible and shapes your priorities for examination and treatment. For example, a high-energy crash or a fall from height raises suspicion for internal bleeding, organ injury, or spinal damage, so you look for those injuries even if the patient seems stable at first.

Vital signs are crucial to ongoing assessment but belong to the physiological check rather than a ZMIST component. Scene lighting isn’t a diagnostic element in this framework, and medical history, while important, is gathered separately and isn’t a defined part of ZMIST. Therefore, the mechanism of injury is the component included in ZMIST.