Most triage has been done on a three level tier, typically labelled Emergent, Urgent and Non-Urgent frequently represented by the colors displayed here. The problem with this system is that in the middle, between the patient getting CPR and the patient with the sprained ankle, it can get difficult to sort out and assign the right spot in line for patients. In the late 1990s, 5 tier triage systems began to be developed and tested/used in hospitals in the US and elsewhere. The five tier system that is the most common is called the Emergency Severity Index or ESI. ESI allows for categories 1-5, from most sick to least, in triage assignments. At the risk of getting overly technical, this is the algorithm for ESI triage decision making. Click on image for larger view.
ESI level 1 patients are basically anyone who is going to die without the immediate full bore attention of both ER nurses and doctors. If the answer to the first box's question is "yes," you are looking at a bona fide emergency.
ESI level 2 evaluations get a little more technical and rely a little more on the triaging person's clinical skill. It swings on the question, "Can this patient wait much to be seen?" Three questions are asked to determine the patient's "waitability": 1. Is the patient at a high risk of getting worse without treatment? 2. Are they newly or acutely confused, lethargic, disoriented? 3. Are they in severe pain, distress?
Patients who do not merit a "yes" on any of the above, and can wait a bit to be seen, are then are evaluated again in a third step. How many "resources" will they need? A resource is something that may be done to evaluate the patient--an x-ray, a lab test--or to treat/help the patient--intravenous medications or fluids. It must be noted here that the physical exam and evaluation by the doctor is not a resource. Patients presenting needing no other resources, or one resource for the evaluation and care of their complaint are categorized ESI 5 and ESI 4, respectively. Those needing two or more resources become ESI 3, unless they have vital signs that are markedly abnormal--that can kick them up to a ESI 2.
So, out of our 5 categories of patients, ESI 1 and ESI 2 need to be in the ER. ESI 1 patients compose 1-3% of ED patients. ESI 2 patients compose 20-30% of ED patients. ESI 3 compose 30-40% of ER patients. Some ESI 3 patients definitely belong in the ER. ESI 4 and 5 compose 20-35% or perhaps even more of the ED's patients. The exact mixes of levels is variable, due to differences in a community's demographics, the type of ER (for example, trauma centers will see more ESI 1s), and medical resources.
I just reviewed Warm Sock's entry. Her son fell, and had tenderness, deformity, pain and limited motion to his arm after his fall. We know right away that he will be at least an ESI 4, as he will need an x-ray. Assuming no circulatory compromise, he can wait a period of time to be seen. He could need an ortho consult or a pain shot, which would make him a ESI 3, but he is stable and not likely to become unstable. The main difference between an ESI 2 and an ESI 3 is in the waiting. ESI 3's can wait both in the waiting room and in the ER itself.
The drunk girl in the room with Socks and her kiddo sounds like an ESI 5. She could walk and talk. I don't know why parents take their drunk kids to the ER. Parents of girls seem particularly prone to this. I also don't know why docs give these girls IV fluids. They should wake up to the nasty hangover they deserve... OK, sidebar over, back to our topic.
So, did Warm Socks need to take her kiddo to the ER? Let's look at the resource he needed--an x-ray. He did need an x-ray, preferably within hours of the injury. Where can you get an x-ray done and read in America? Most doctor's offices do not do x-rays. The ER becomes the place for this. He then will need a doctor's expertise and physical care for the injury. Where can you get this done in a timely manner? Not most primary care providers. PCPs are usually not able to take unscheduled patients. They send them--oh, where?--to the ER! So people who could be seen in another setting are routinely seen in the ER--perhaps in a Fast Track or Urgent Care setting within the ER--but still in the ED.
Well I hope this little peek inside the world of the triage nurse was helpful. If you are just dying to read more about triage using the ESI system, here's a link. Feel free to use the comments to ask questions.
In the end, the ER was the right setting for our klutzy young friend due to its easy access to the resource(s) he needed. If there was a realistic option for timely evaluation and care other than the ER, that could have been used. However, just ask a concerned mother with a kiddo making "ouch" noises and a bend in his arm that God did not put there to wait for more than a couple hours...yeah, I didn't think so.