Research review: Putting CDC field triage guidelines to the test

Throughout the country, our hospital emergency departments are short-staffed and flooded with patients lining the hallways. Healthcare professionals are tasked with thinking about how they’re going to triage that patient who just came in from a car accident or the one suffering from a cardiac arrest. They’re calm, cool and collected despite the environment that surrounds them.

Considering their limited resources today, field triage guidelines are crucial to get patients to the most appropriate trauma center and alleviate some of the stress trauma systems face.

For more than three decades, the American College of Surgeons Committee on Trauma (ACS-COT) has set guidelines for the field triage process, which have been widely adopted by trauma systems across the United States to drive EMS transport decisions and to establish hospital-based trauma activation criteria. In 2011, the Center for Disease Control and Prevention (CDC) collaborated with the ACS-COT to update the triage guidance related to the physiologic, anatomic, mechanism of injury and special considerations criteria. The latest guidelines were released in 2021.

Field Triage Guidelines broken down

In 2021, the CDC released an updated edition of the 2011 Field Triage guidelines, which distinguishes between patients needing the highest level of trauma center care and those who don’t:

• Guidelines are now formatted in the typical manner that EMS clinicians collect patient assessment information.
• They also distinguish between patients needing the highest-level trauma center available and those that would benefit from care at a trauma center (not necessarily the highest-level trauma center).
• Rather than using the total GCS≤13, the new criteria use only the motor score of <6 to identify patients in need of the highest level of trauma center available.

The CDC Field Triage Guidelines include four steps:

1. Levels of consciousness and vital signs. Is the patient breathing or responding?
2. The patient’s anatomy of injury. Are there any apparent extremities like broken bones?
3. Mechanism of injury. How bad was the car accident clinicians responded to?
4. Special considerations. Provider judgement, pregnancy, child abuse.

Ideally, field triage guidelines facilitate the transport of the right patient to the right level of care while avoiding both over-triage and under-triage.

• Under-triage: patients missed by field triage processes and transported to non-trauma hospitals, which may lead to a higher likelihood of death.
• Over-triage: patients with minor to moderate injuries identified by field triage criteria as having serious injuries and transported to trauma centers unnecessarily. This leads to an overuse of limited resources and inefficiency in the system.

Independent collaborators who published a study in the Journal of Trauma and Acute Care Surgery looked at national field triage guidelines and compared the two. According to the study, trauma systems have prioritized the goal of minimizing under-triage and accepting a higher level of over-triage to avoid increased mortality.

A systematic review of field triage performance across all ages showed 14% to 34% under-triage and 12% to 31% over-triage. Under-triage of children is up to 51% and has increased with recent triage guidelines.

As an EMS clinician, how do you make sure you aren’t over or under-triaging? Field Triage Guidelines are significant in theory, but limited information has existed that links the performance of these guidelines with patient outcomes – until now.

Field Guidelines put to the test

A recent study published in the Journal of Trauma Nursing from the 2019 ESO Data Collaborative looked at 911 responses and the emergency department dispositions to understand the relationship between Field Triage Guidelines and hospitalization or death rates. The data did not include children and cardiac arrests prior to EMS arrival.

As EMS clinicians often play a vital role in early evaluation and care for injured patients, these comparative findings can help inform EMS destination decisions and the creation of trauma center-specific activation criteria for patients meeting select CDC Guidelines steps.

The 2019 research dataset looked at roughly 8.3 million EMS encounters among 1,322 EMS agencies who agreed to participate in a health data exchange that linked emergency department hospital outcome records with the prehospital patient records. Out of the 8.3 million records, over 86,000 cases met the inclusion criteria.

Tracking outcomes using linked hospital outcome data

The hospitalization outcome data compared patients admitted or transferred to another hospital to those discharged alive from the ED, including those who left against medical advice or who left without being seen, versus those who were not discharged from the ED. The evaluation of hospitalization excluded patients who died in the ED.

The mortality outcome dichotomized patients who were discharged alive versus patients who died in the ED or in hospital setting. Patients who were transferred to another facility and those who did not have inpatient disposition data available at the end of the study period were excluded from this measure.

ESO

The results

In the study, screening positive for one or more of the Field Triage Guidelines was associated with a higher likelihood of being hospitalized or dying – although the predictive power varied by each guideline.

1. Anatomy of injury and vital signs and level of consciousness led to increased odds of hospitalization.
2. Meeting the vital signs and level of consciousness guideline led to increased odds of death.
3. Meeting multiple guidelines led to higher odds of being hospitalized and death.

Further, 99.9% of patients who met the mechanism of injury guideline survived, which supports the 2021 Field Triage Guideline’s proposed changes to the trauma triage criteria that recommend transport to a locally available (not necessarily highest level) trauma center for patients whose only risk is mechanism. This may have a significant impact on patients and EMS providers in rural areas.

Triage takeaway

Patients meeting multiple CDC Guidelines for Field Triage of Injured Patients steps were at greater risk of hospitalization and death. Among those positive in only one step, anatomy of injury, vital signs and level of consciousness criteria were associated with a greater risk of hospitalization. In comparison, vital signs and level of consciousness criteria were associated with a greater risk of death. Collectively, these findings may help inform EMS destination decisions and the creation of trauma center-specific activation criteria for patients meeting select CDC Guidelines steps.

Key points:

1. Patients meeting multiple CDC Guidelines Field Triage of Injured Patients steps were at greater risk of hospitalization and death
2. Vital signs and level of consciousness were associated with the greater risk of death among those only meeting one step.
3. The mechanism of injury appears to have limited predictive power.

To request the full manuscript, you can submit a request to the ESO research team by clicking on request a publication reprint and selecting “Patient Outcomes based on the 2011 CDC Guidelines.”