EMT Practice Questions

The correct answers are

C.  

E.  

In patients with acute coronary syndrome (ACS) who are NOT hypoxemic, routine oxygen administration is no longer recommended because it may actually be harmful.

Key pathophysiology:

1. Coronary Artery Vasoconstriction (E):

High concentrations of oxygen can cause vasoconstriction of coronary arteries, which reduces blood flow to already ischemic heart tissue.

“Supplemental oxygen in non-hypoxemic patients may cause coronary vasoconstriction.”

2. Increased Tissue Damage (C):

Excess oxygen can lead to oxidative stress and worsen ischemic injury, potentially increasing infarct size or tissue damage.

“Hyperoxia may increase oxidative injury and worsen myocardial damage.”

Why the other options are incorrect:

A.  

Reduced mortality: Evidence does not support mortality benefit in non-hypoxemic ACS patients.

B.  

Resolution of chest pain: Oxygen does not reliably relieve ischemic chest pain unless hypoxia is present.

D.  

Reduction in infarction size: Studies show no benefit and possible harm.

NREMT/AHA-aligned guidance emphasizes:

“Administer oxygen only if SpO₂ is less than 94% or if the patient is hypoxic.”

Routine oxygen in normoxic patients is not recommended and may be harmful.

Exact Extracts (NREMT/AHA-aligned references):

“Avoid routine oxygen use in patients with normal oxygen saturation.”

“Hyperoxia can cause coronary vasoconstriction.”

“Excess oxygen may worsen myocardial injury.”

Clinical Priority Summary:

In non-hypoxemic ACS patients, oxygen can cause harm rather than benefit, specifically vasoconstriction and increased tissue damage, making C and E correct.

The correct answers are

A.  

B.  

F.  

Why A is correct (High-visibility vest):

EMS providers must wear ANSI-compliant reflective vests when operating on roadways

This significantly improves visibility, especially at night

NREMT-aligned guidance states:

“Wear high-visibility apparel when operating near traffic.”

Why B is correct (Limit scene time):

Reducing time on the roadway minimizes exposure risk

Rapid assessment, treatment, and transport are key safety strategies

“Minimize time spent in hazardous environments.”

Why F is correct (Wheel positioning):

Turning wheels toward the scene helps:

Prevent the ambulance from being pushed into responders if struck

Provide a protective barrier

“Position vehicles to protect the scene and personnel.”

Why the other options are incorrect:

C.  

Keep back turned to vehicles❌ Dangerous — EMTs should face traffic when possible

D.  

Place flares 10 feet away❌ Incorrect distance — flares should be placed much farther away for advance warning

E.  

Reduce scene lighting❌ Incorrect — proper lighting is essential for scene safety and visibility

Exact Extracts (NREMT-aligned EMT educational references):

“Use reflective safety vests when working on roadways.”

“Limit exposure time in hazardous scenes.”

“Position emergency vehicles to create a safe work zone.”

Clinical Priority Summary:

Key roadway safety measures include visibility, minimizing exposure, and proper vehicle positioning, making A, B, and F the correct answers.