How Triage Works in a Hospital

Determining Who Needs Emergency Attention First

The term “triage” means sorting out. Medically, it’s a process used to prioritize who needs emergency medical attention first, whether injured or sick people or disaster survivors.

Patients are triaged or prioritized according to their need for emergency care. Resource availability is also taken into account during this process.

Triage may be performed by emergency medical technicians (EMTs), hospital emergency room gatekeepers, soldiers on a battlefield, or anyone with knowledge of the system during an emergency situation.

This article explains what medical triage is, how it works, and when it is used. It also covers different types of triage and the developments that are changing the triage landscape.

Why Is It Called Triage?

The word “triage” comes from the French word trier, which means to sort or select. Its historic roots for medical purposes go back to the days of Napoleon when triaging large groups of wounded soldiers was necessary.¹

Over the centuries, triage systems have evolved into a well-defined priority process, sometimes requiring specific training depending on the setting or organization that uses the system.

How Medical Triage Works

Each organization has its own triage system. They all create priorities for who gets care or is transported for care. The most common triage systems use color coding.

These are examples of the five categories or levels of triage that an organization may use:²

• Red: The individual needs immediate attention for a critical life-threatening injury or illness and may be transported first for medical help.
• Yellow: The individual has serious injuries that need immediate attention. In some systems, yellow tags are transported first because they have a better chance of recovery than red-tagged patients.
• Green: This could indicate less serious or minor injuries that are non-life-threatening. Transport may be delayed.
• Black: This could indicate an individual is deceased or mortally wounded. It may mean that they are beyond help and, therefore, are a lower priority than those who can be helped.
• White: The individual doesn’t have an injury or illness.

Triage systems run the gamut from verbal shouting in an unusual emergency to well-defined colored tagging systems used by soldiers and EMTs when they arrive on the scene of a multicasualty accident or a battlefield with many wounded soldiers.

Process of Triage

Triage works differently in different settings. It will be slightly different in a hospital than at the site of an accident or disaster.

Before the Hospital

According to the 2021 National Guidelines for the Field Triage of Injured Patients, the first step for emergency medical services is to assess injury patterns, mental status, and vital signs. Severe injuries to any part of the body including the head, neck, torso, spine, or pelvis mean someone is at high risk, or in the “red” category.³

Patients meeting these “red” criteria need to be transported either to the highest-level trauma center available or to the closest hospital first for stabilization and then to a trauma center. Patients meeting the “yellow” criteria are also at risk of serious injury, but theirs is moderate.³

The “yellow” criteria are concerned with how the injury occurred. They recommend transporting someone who’s been injured in a motor vehicle, bicycle, or pedestrian accident to a trauma center for care. Likewise, the EMT may make a judgement to send someone to a hospital based on whether that person uses anticoagulants, is pregnant, or has other risk factors.³

In the Hospital

Once the patient arrives at the emergency room, hospitals will use their triage systems to prioritize patients according to severity of the trauma and available resources. More than 70% of emergency departments across the United States use a triage system called the Emergency Severity Index (ESI).⁴

The ESI was developed in 1999 and uses a five-level triage algorithm to sort patients into groups based on how dire the situation is and what resources are available. Level I is the most urgent and level V is the least urgent.⁴

Triage nurses help evaluate patients and decide the priority of care in an emergency room and other medical settings. They update the medical team on the patient’s status and provide emergency care when needed.

When Medical Triage Is Used

In the U.S., emergency rooms may be full of people who need immediate attention plus people who are seeking treatment for less serious conditions. The department may be staffed just to meet the expected need.

When there are too many patients and not enough personnel or resources, triage is used to determine who gets care first. This ensures the patients who need lifesaving treatment are seen before those who have less serious conditions.⁵

Hospital resources can include things like laboratory and X-ray facilities, such as the equipment and personnel need to run the equipment.

Triage may be a short-term need, as when there is a vehicle accident with multiple casualties needing ambulance transportation. Or, it may be a long-term need for a hospital that is often understaffed for the number of patients who arrive at the emergency department.

Types of Triage

Different types of triage are needed for different situations:

• Emergency department triage: This is used by hospitals when patients arrive at the emergency room.
• Incident (multicasualty) triage: This is used for any situation involving injuries to multiple people, such as in a motor vehicle accident.
• Disaster (mass casualty) triage: Similar to incident triage, this type involves injuries to a large number of people, such as after a terrorist incident or a natural disaster. The most commonly used triage system in the U.S. for these emergencies is called the START triage system, which can evaluate an adult in about 30 to 60 seconds.²
• Military (battlefield) triage: This is used to treat injured soldiers on the battlefield.²
• Telephone triage: This occurs when a nurse listens to your symptoms and assesses your need for care over the phone outside of normal operating hours. The nurse lets you know whether you should see a doctor, go to the emergency room, or try at-home treatment. The nurse can also call an ambulance in life-threatening situations.⁶

Changes to Triage

Triage systems have been changing due to technology.⁷ Technological advances like telehealth have been able to transform the healthcare environment.

For example, providers at rural hospitals that cannot afford the latest equipment or high-level specialties can now connect more easily with trauma centers through increased use of telephones, cell phones, the Internet, and closed teleconferencing systems.

Telephone triage is another example of how technology is being used to make health services available to more people in more situations.

Artificial intelligence (AI) is another technological development that is changing emergency medical treatment. The triage process of assessing a patient is subjective.

Two nurses evaluating the same patient can sometimes disagree about the patient’s level of care. Thanks to AI, patients can now be triaged more objectively.⁸

An AI algorithm that combines the triage evaluation data with the patient’s medical history has been shown to recommend a more accurate triage level of care—and it does this within a matter of seconds. It also provides an explanation for how it reached its decision, allowing care providers to follow the logic before taking action.⁸

These AI systems are already being used in hospitals in several states including Maryland, Florida, and Connecticut. They are proving to be an invaluable triage tool.⁸

Summary

Triage is the prioritization of injured or sick individuals based on their need for emergency treatment. Each organization will have their own triage system, which often includes color-coded or numbered categories.

Triage may be used to meet an organization’s short or long-term needs to help determine who gets care first. People with life-threatening injuries are prioritized over people with minor injuries. The type of triage system a hospital uses will be different from the system used by emergency medical technicians or in disaster situations.

Technological advances are changing how triage works. Telehealth gives more people access to health information in emergencies, and artificial intelligence can be used to triage patients more accurately than before.