How does the emergency room (ER) staff determine who to see first?

Dr. Kathleen Handal, MD
Emergency Medicine Specialist

The system for determining who gets seen and in what order is called the Emergency Severity Index (ESI) and it was designed for use in ER triage by the US Department of Health & Human Services. The ESI is a five-level algorithm that prioritizes patients into five groups (levels) from 1 (most urgent or most acute) to 5 (least urgent or least acute) on the basis of seriousness and the resources that person may need. Triage staff use specific criteria to determine each patient’s acuity. They interview you (just a short talk), take your vital signs (blood pressure, pulse, measure your oxygen saturation and respiratory rate--the number of times a minute you take a breath). If you have pain you will be asked on a scale of 1-10 your pain level. This all helps to determine your ESI level.

For example:

  1. Resuscitation (trauma, cardiac arrest, heart has stopped)
  2. Emergent (life or limb threatening, chest pain, stroke)
  3. Urgent (abdominal pain)
  4. Non-urgent (vaccinated child pulling at ear, cold)
  5. Referred (medication refill)

A well-implemented ESI program helps hospital ERs rapidly identify patients in need of immediate attention, ready resources and allows them to better identify patients who could safely and more efficiently be seen in a fast-track rather than the main ER. This system also allows a busy hospital to more accurately determine the ER’s need to go on ‘diversion’--that is, ask that ambulance patients be taken elsewhere as capacity has been reached. Diversion status occurs only under set situations usually decided by the local EMS system.

The emergency room (ER) staff uses a triage system to determine who to see first. ER staff sees the sickest people first. For example, if someone comes in with a heart attack, and someone comes in with a cough, obviously the person with the heart attack is probably going to take precedence. In the triage system, everyone is given a number, one through five. Someone who is essentially actively dying is going to be a one, and somebody coming in for a scratch, or because a toe hurts, might be a five. Depending on peoples' acuity level, they'll be assigned one of those triage numbers. ER staff tries to see everyone as fast as they can, but the sicker people are going to be seen first. 

When a patient first arrives in the emergency room—now typically called the Emergency Department—the first stop is triage. In triage, a nurse typically prioritizes each patient's condition into one of three general categories:

  • Immediately life threatening
  • Urgent, but not necessarily immediately life threatening
  • Less urgent

Categorization is necessary to ensure someone with a life-threatening condition is not left waiting just because he or she arrived a few minutes later than someone with a less severe problem. A triage nurse will record a patient?s vital signs (temperature, pulse, respiratory rate and blood pressure). The nurse also will get a brief history of a patient?s medical complaints, medical history, medications and allergies. She will use this information to determine the patient's appropriate triage category.

After triage, the next stop for a patient will be registration. It is not very exciting and rarely seen on TV. Nonetheless, during registration, patients provide insurance information, Medicare, Medicaid or HMO card. This is a necessary step and helps to develop a medical record so the medical history, lab tests, X-rays, etc., will be located on one chart and can be referenced at any time. The bill, of course, also will be generated from this information.

If a patient's condition is life-threatening or if a patient arrives by ambulance, registration may be completed later at the bedside.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.