EM Mind Set: Approach to the Undifferentiated Patient

Lecture Notes

Not Just the Rule-Out Doctor, But We Do Rule-Out Like It Is Going Out of Style

This lecture focuses on explaining how emergency physicians think and the inherent pressures of working in an acute environment. For details on how to approach patients AND improve your efficiency while on shift, please review our “ED Work Flow” lecture.

The Uncertainty Principle

The Emergency Room (ER) is a place of boundless uncertainty. To thrive in this environment, you have to learn how to limit the uncertainty and feel comfortable making decisions with limited data in a timely fashion. This requires a different skill set than what is taught in medical school, where most of the training occurs in the clinic or inpatient setting. Clinic patients usually have self-selected lower risk chief complaints and may have an established history with the provider or health system caring for them. In the clinic setting, the pressure to rule out is blunted by the fact that most of these patients have low-risk chief complaints that are usually subacute to chronic in nature (when they are acute they are seen in urgent care or ER). In the inpatient setting, you are typically managing patients that are partially or fully differentiated. The focus on the inpatient side is more on treating a known diagnosis or completing the workup for a partially differentiated patient with a high-risk chief complaint. In the inpatient setting, a few factors relieve the pressure of immediately ruling out life-threatening conditions:

  • The patient may already be partially differentiated

  • The patient is in in a safe monitored environment

  • There is no pressure to disposition patients at the 2 to 4-hour mark (more on this below)

In both of these scenarios, the pressure to immediately rule out life-threatening illness is blunted. 

The Name of the Game: Clear the Waiting Room 

In the ER, every patient must be seen regardless of chief complaint—we do not close at 5 PM and have patients come back the next day. The ER is open 24/7, but it does not have the unlimited resources required to see all the patients that may arrive. The goal of every shift is to clear the waiting room so that we can keep ER beds (aka resources) empty and available for the inevitable next bolus of patients. Therefore, there is a pressure to disposition patients at the 2-hour and 4-hour mark. The 2-hour disposition mark is for patients that very clearly do not have an acute life-threatening illness or for those very sick patients that clearly require an admission. The 4-hour disposition mark is for every other class of patients.

Rule-Out First, Diagnose Second 

This functional time constraint forces ER providers to make decisions with limited data and helps explain why we initially focus on ruling-out life-threatening conditions. In the initial phases of a patient encounter, it is often easier to think about WHAT ISN’T going on than it is to know WHAT IS going on. Whittling down the degree of uncertainty by initially focusing on a smaller list of life-threatening diseases related to the chief complaint (the critical differential) provides a level of comfort and acts as a scaffolding from which to build the remainder of your encounter. The initial orders reflect what is needed to rule out items on the critical differential, and as more data is gathered, the provider doubles back to think about what is most likely going on. Otherwise, the uncertainty can be paralyzing and anxiety-inducing especially as the patients waiting to be seen pile up.

The EM Detective

The aforementioned reality means that the goal of the approach to the undifferentiated patient in the ER is to convince yourself that you have sufficiently ruled out everything on your critical differential. You focus on utilizing evidence-based historical points, exam findings, laboratory values, or imaging to help you decrease the likelihood of critical disease. This rule-out must be performed prior to final disposition. Physicians are like medical detectives that use clinical clues to solve patient cases. In the emergency room you only have seven clue-gathering methods:

  • Obtaining a history

  • Physical examination

  • Laboratory values

  • Imaging

  • Consultants

  • Observation time/Chart review

These are the only clues at your disposal that will help you solve clinical cases. You may not need to use all seven items on this list to solve a case, but when you cannot obtain an appropriate history or have a limited physical exam, you will need to rely on the remaining five items.

Ask Yourself One Question

The best way to understand the EM brain is to ask yourself one question:

What percentage of potentially life-threatening illnesses do you feel comfortable discharging from the ER without appropriate workup or treatment?

In the current medicolegal environment, the acceptable miss-rate for a potentially life-threatening disease is less than 2%. We all strive to get that percentage as close to 0% as possible, but we understand that there are different barriers that prevent us from reaching that goal. For example, patients with low-risk chest pain by HEART score (a prospectively validated scoring system to risk-stratify the likelihood of Acute Coronary Syndrome) still have a 0.9-1.7% risk of a major adverse cardiac event (MACE) at 6 weeks. To provide perspective, the HEART score is one of the best clinical decision tools developed for the assessment of chest pain in the ER and the best we could do was bring the risk of MACE down to ~1.7%.  It is extremely difficult to miss 0% of life-threatening conditions.

How do we bridge the gap between the expectation of not missing anything EVER and reality? We do it by utilizing evidence-based historical points, exam findings, laboratory values, and imaging results that have a high sensitivity for ruling out the diagnosis in question. The onus is on you to know if the tools you are using are sufficiently sensitive to rule out “badness.” For example, time of onset of a headache to when it reaches maximal intensity (aka thunderclap headache) is a fairly sensitive initial question to risk stratify if your patient should be worked up for a subarachnoid hemorrhage (so don’t forget to ask that question in your patient encounter for headache!).

Residency Is A Calibration Process

Residency is a special time in training that allows you to practice as if you were in a bowling lane with the bumpers up. It is an inherently safe space in which you get to test the boundaries of how you plan on practicing when you are an attending. In your junior years, you want to be as conservative as possible until you begin to gain some clinical experience. You do not want to be the doctor that doesn’t take any chief complaint seriously and discharges everyone with minimal workup because you think you are an amazing diagnostician after reading Bates' cover-to-cover (you need both book AND clinical experience to be an outstanding doctor). You also do not want to be the doctor that does a full workup on everything and MRIs everyone to clinch a diagnosis prior to discharge.  You cannot shortcut clinical experience, otherwise, residency would be pointless. The only way to gain clinical experience is by seeing as many patients as possible. You need to see hundreds of abdominal pain patients to appropriately calibrate yourself to all the different permutations of signs and symptoms they may have on presentation. There is always something to learn in every patient encounter. You have to actively seek out your education, constantly poking and probing for holes in your medical knowledge. Be honest with yourself and ask yourself how clearly do you understand the disease process in question. Make a list of topics or clinical scenarios which are fuzzy in your head or of chief complaints that make you uncomfortable/avoid (chances are you are avoiding them because you don't have a firm grasp on the topic). Lastly, at the end of each patient encounter, you should mentally drill yourself on what you would do if the patient presented more critically. After a while, this becomes second nature and you will begin to build a level of comfort and confidence that will carry over to when you are an attending. Residency is not easy and your learning curve is not always linear but you will eventually gain the competency to practice on your own.  

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