An EPiC mental model. St Emlyn’s

The practice of coordinating, consulting and managing an entire acute clinical service in real-time is fairly unique to emergency medicine. Not many other specialties require the level of fast-paced situational awareness, nor carry the simultaneous risk for multiple patient care events as emergency physicians do. Central to this is the EPiC (or emergency physician in charge) role. Being effective in the EPiC role is essential to maintain safety and deliver quality care in Emergency Departments (EDs).

I have been an emergency physician for fourteen years. I have practiced both in the NHS and in African resource-limited settings – mainly in South Africa. During this time, I borrowed from much smarter colleagues than me, to develop the mental model I use for the EPiC role today. 

Much of this post will be familiar to the experienced emergency physician, but for those new to the role and in training I hope there will be some useful tips and tricks here. For the more experienced readers, I would love to get feedback on what you do and what works best in your practice.

Circles of care

My first and most important principle is something I call circles of care. I bet there is a better term, but for some reason, circles of care stuck. Simply put, circles of care define the priorities of various ED workflows and their boundaries in a stepwise fashion. I use three circles. After reading this you may define more or less, but the principle remains the same: each circle sets a boundary that protects the priority of the workflows inside the circle.

The inner circle defines your highest priority workflow. These are situations/ patients where the outcome is time-dependent (must be done within 60 mins): major trauma, STEMI in waiting room, compromised patient on ambulance ramp, etc. These situations/ patients may not necessarily be in one location. It requires a specific, individual-level focus.

The second circle defines the well-being of staff on shift. In general, this tends to refer to breaks. But within the context of a high-stakes circle 1 event, this may also refer to hot debrief. When it is busy we often sacrifice our wellbeing to the queue. And when we EPiC, we can inadvertently extend this to our team. There is now sufficient evidence to show that sacrificing breaks also sacrifices safety. Staff wellbeing whilst on shift is an important priority to protect.

The third circle defines areas of high risk and high congestion. These areas require a constant turnover to minimise risk and congestion. In my service these are our Corridor spaces, the Majors area and children’s areas. If I am unable to maintain constant turnover in the Corridor and Majors, I am unable to offload ambulances, thereby increasing risk. If I am unable to maintain constant turnover in our children’s area, it’ll spill over into the adult area, also increasing risk. It requires a general, area-level focus.

Anything that does not fit within these three boundaries sits outside the boundary of the third circle. In my service this mainly means Minors. What you place in the circles and where often change across the course of an EPiC shift. As new situations present: eg. ramped ambulances, Minors patients that should be on Majors, Corridor congestion, delay in Triage paired with a jam-packed waiting room, etc. I slot these into the appropriate circles.

Learning how to identify circles of care is one of the first things I establish when I work in a new environment. I can usually identify circle 1 from the Electronic Patient Record. Circle 3 isn’t always that obvious; I recommend a conversation with the nurse in charge who will point out the areas that can cause risk from congestion. Delay in Triage during high demand tends to get me nervous as I cannot see the risk. Circle 2 usually needs a quick check in with clinical staff. This serves a double purpose as it also allows me to tell individuals how I want to deploy them.

Circles of care provide a very simple model to communicate your decisions with your nurse in charge or managers: “I moved clinical staff from Minors to care for the three major trauma patients that just arrived in Resus – this will delay the Minors workflow”, or “Some of my clinical staff are taking safety breaks. Those on the floor are focusing on the influx into Majors – this will delay the Minors workflow”. See how I used the circles to justify my decisions?

The four S’s: staff, space, stuff and systems

The second principle is essentially a layer I apply over my circles of care. The concept of the four S’s is well defined in surge capacity models. The availability of staff, space, stuff, and systems affect how I am able to action the various workflows. And no shift is ever the same. I think of the four S’s in terms of the four nations from the popular Avatar series. Just like the four elements: fire, air, earth and water bring balance to the world: staff, space, stuff and systems bring balance to your EPiC workflow.

The Fire Nation, as a very organised society, represents staff. Staff affects circles of care not just in overall numbers, but also skill mix and scope. Sufficient staffing should be able to cover all areas, but if you have a patient demand/ staff supply mismatch, circles of care will be affected. Not everyone has scope to work in circle 1 without support. Some staff only work outside circle 3. To deliver safe care, staff need to match the moving demand within the circles of care, with the inner circles protected. This means that rota vacancy will likely result in adequate staffing allocation for circle 1 activity, but relatively less for activity outside circle 3. Accepting poor staffing can’t be made to cover all areas equally is an important acknowledgment in the EPIC role. It helps us to move on to a cautious compromise.

The Air nomads live in wide open spaces in their mountain air temples. They represent space. Space has sadly become a very stressful variable. It is very likely that you will not have agency over all the clinical spaces in your ED. Use of non-designated spaces especially corridors have become commonplace. At some EDs these may include pre-ED cohort areas, and even the ambulance ramp. Use of these areas pose an increased risk to staff and patients. I assign circles of care depending on the priority. A critically ill patient on the ambulance ramp will be in circle 1, whereas a patient in the corridor who has already been seen, clerked and post-taked will probably be outside circle 3. Understanding the space accessible to us allow us to mentally understand the capacity we have for each priority, and plan/ escalate accordingly.

The Earth kingdom builds vast cities through earth and metal bending. They represent Stuff, or resources. Working, functional resources such as the Electronic Patient Record (EPR) or Imaging software are pivotal to safe, efficient emergency care. But so are everyday things we take for granted: working lifts, office space and equipment. When resources are insufficient, ineffective or inaccessible, it compounds risk, complicating patient care.

And finally, the Water tribe. The water tribe learned water bending from the moon’s ebb and flow effect on the ocean. They represent systems. Systems provide a framework by which we work. Same Day Emergency Care, Acute hospital flow and Virtual Ward are all systems outside ED created to support urgent and emergency care flow. These are often neglected or underdeveloped and often not under ED control. But there are systems under ED control that adds value to patient care. These include systems to deliver initial assessment within 15 minutes of arrival, criteria for safe corridor use and management of ramped ambulances. These can seldom be developed on the fly. Systems development requires dedicated time, development and testing. Knowledge and application of systems inside and outside ED support your circles of care when you are the EPiC.


The third principle is something I call bookmarking. As EPiC you will be pulled in a million directions: sign this ECG, prescribe some analgesia, can I have a consult, etc. Your working memory is simply not sufficient to hold so much at any one time; and you’ll tire quickly if you try to. You can assign some memory to your memory archives. But once you do, it is no longer readily accessible when you need it; you’ll only remember it when you relax at home after your shift. 

It is therefore important to have a system to bookmark outstanding tasks. This will differ from service to service. I am able to place a short note on our EPR’s patient tracking screen. I also use symbols, such as an asterisk for outstanding imaging requests or patients I want to personally review/ delegate a review. I hold onto drug charts when I’m asked to prescribe.

When I worked in South Africa I collected patient stickers which I wrote on. When I completed an outstanding task I’d bin the sticker. You probably have similar ways to remember things. My advice is to formalise your bookmarking practice, so you can use it to aid your working memory in the midst of chaos.

The nurse in charge

It goes without saying that the most important relationship for the EPiC is the nurse in charge. Most EDs will have multiple areas, each with its own shift nurse lead. Although I largely engage with the nurse in charge, I will also check in with the shift nurse leads in other areas. In my ED these areas are Resus, Minors and the children’s area (and at times the corridor – sigh). In some EDs, nurses use radios with earpieces to communicate effectively between each other. I have also seen Teams channels work really well.

Supporting the nurse in charge and nurse leads with decision-making is very important to me. I draw a clear line between clinical decisions and nursing decisions. I find this helpful specifically when challenged by managers or non-EM teams on things related to nurse decision-making. This ensures I do not take away the nurse in charge’s agency, by making nursing decisions that are not mine to make. Example: I decide whether a patient is clinically safe to go into the corridor, but the nurse in charge decides whether it is safe to place another patient in an already used corridor. I would defend my nurse in charge’s decision to managers and non-EM teams.


Much of my EPiC shifts are spent revising and adjusting my circles of care depending on service demands. I use the 4 S’s, bookmarking and my nurse in charge extensively in the process. This allows me the control required to maintain a relative sense of safety. Where it cannot, it allows me to rapidly identify crunch areas in order of priority.

The EPiC role can be highly rewarding, but also terrifying. I have had shifts where it went from Steamboat Willy to Speed in a matter of minutes. Having a mental model, such as the circles of care, provides me with a structured framework to return to. This ensures the best opportunity to deliver the most for the most when it is no longer possible to do anything and everything for anyone and everyone.

I am keen to learn about your models and would value your comments and feedback.

Cite this article as: Stevan Bruijns, "An EPiC mental model. St Emlyn’s," in St.Emlyn's, May 18, 2024,

2 thoughts on “An EPiC mental model. St Emlyn’s”

  1. Very interesting
    Always thought of the importance of sharing a mental model prior to any team approach in the UK
    As I am stepping in to HST training in afew months I found this article very useful.
    Thanks alot

  2. Really helpful, not just for EPICs but for anyone juggling patients/staff/resources

    I’m interested in the ‘bookmarking’

    I see Steve uses asteroid in notes along with a one liner, or patient labels to annotate then discard

    Is anyone using other systems? Voice dictated notes on a ‘to do’ list? Other options?

Thanks so much for following. Viva la #FOAMed

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