The Approach to the ED Patient

During your rotation, we hope to teach you our approach to patients. Our patients are different than those you’ve seen on the hospital floor or physician’s office, so our strategies differ as well.

In order to take into account these differences, our approach varies from the traditional approach, namely the differential diagnosis performed prior to the history and physical. In fact, the differential diagnosis is used to guide your history and physical.

  • In The Office: Review VS → H&P → DDx → Tests → Dx → Tx → Dispo
  • In The ER: Primary Survey → DDx → H&P → Tests → maybe a Dx → Tx → Dispo

On the hospital floors & in the office

On the hospital floors, your patients often have the benefit of an established diagnosis. This comes from prior workup (possibly from the emergency room). You may have various lab testing, EKG’s, radiologic studies or previous diagnoses from the patient’s old chart.

Your history and physical gathers this information and uses it to form your differential diagnosis. Once your diagnosis is made, you concentrate on treating the patient’s condition.

In the physician’s office you may not have all the information you had on the floor, but most of the time you have the luxury of knowing the patient and their past history. Most physicians have a relationship with their patients that can span years, so they are well-informed of their patient’s medical conditions.

So when a patient comes in with a new complaint, a commonly taught strategy to create a differential is to perform a history and physical then formulate a differential diagnosis.

  1. Review vital signs addressing any abnormalities
  2. Perform your history which expounds upon the patient’s chief complaint and physical
  3. Use this information to generate a differential diagnosis of common etiologies
  4. Start diagnostic testing to confirm or refute the likely suspects
  5. Once diagnosis made, initiate treatment
  6. Make a disposition (admit patient, refer to a specialist, discharge with timely follow-up, discharge till their next visit)

In the Emergency Department

The patients who present to the emergency room are usually brand new to us. There is no luxury of years of a past relationship or prior workup. We don’t start with any diagnoses. This is your job to find out!

Our patients are also inherently different than those who go to see their doctor. Something prompted them to think they cannot wait to see their primary physician but should instead urgently seek care. Many times they are right. In other words, they are more likely to have something bad going on.

The emergency physician also functions under different constraints. Patient’s diseases often progress quickly, so timeliness is important. There is an endless stream of people coming to the department who also need to be treated. You need to skillfully make a disposition on your current patients to make room for the others who may be just as ill (or sicker).

Why the EM approach to patient differs from the “traditional” approach

  • We don’t have a past relationship with them
  • We often don’t have the results of any of their prior testing
  • They are more likely to have an acute illness requiring intervention
  • Patients keep arriving, so we need to be quick yet thorough
  • Our patients are more likely to decompensate quickly

So our approach should allow us to quickly establish a rapport and utilize what limited information we have available. We need to be constantly aware of potential life threats – what could kill this patient, and act upon that should they deteriorate. To be quick yet thorough means we need to be focused.

  1. Review VS and chief complaint, assess primary survey and resuscitate if necessary
  2. Form your differential diagnosis (based on chief complaint, age, gender and vitals) which includes all life- and limb-threats
  3. Take a focused history and physical (secondary survey) based on your differential diagnosis
  4. Diagnostic testing to further refine your differential
  5. Initiate treatment (medications, consultations, procedures) often without benefit of a diagnosis
  6. Make disposition (admit or discharge)

Initial actions & Primary Survey

As you are walking toward the patient’s room, the first thing you should do is look at the patient’s chief complaint, age, gender and vital signs. A world of information is contained in those few pieces of information.

Look for vital signs which are abnormal. This can clue you into a patient who may require immediate resuscitation.

Certain chief complaints require things to be done in a timely fashion: getting an EKG within 10 minutes of arrival in patients with chest pain or ordering a CT scan in a patient with a suspected stroke.

Primary Survey

When you enter the room, look at the patient and perform your primary survey:

  1. Is their airway intact?
  2. Are they breathing on their own? Ventilating or oxygenating efficiently?
  3. Are they circulating their blood efficiently?

This can be done in a few seconds. Also note the vital signs. If your patient is in need of immediate intervention, go do it! If you note a blood pressure of 60/30, heart rate of 140 and pulse ox of 87% — get in that room fast and treat it.

Placing a patient on IV, oxygen, and cardiac monitor after (or while) addressing the ABC’s is a good practice for potentially ill patients. Recite it like a mantra:

ABC’s and IV, O2, monitor.

Remember to consider these in all your ED patients

Form a Differential

Next, use the initial presenting complaint to form a differential diagnosis. This differential should be broad enough to encompass all possible life-threats presenting with that chief complaint. The patient’s age, gender, vital signs and chief complaint will guide your formation of a differential.

Note that the differential has been formulated prior to taking the history and physical. This doesn’t mean the H&P can suggest new diagnoses, but at the very least you are approaching the patient with fatal illnesses at the forefront of your mind.

It helps to have these differential prepared ahead of time, so whenever you have a patient with a headache, you automatically consider the same life threats (subdural bleed, epidural bleed, subarachnoid bleed, meningitis, tumor…) without forgetting something important.

Secondary Survey

After your primary survey and any necessary stabilization, take another look at the patient. Recheck their vital signs. Now perform your focused history and physical. This is your secondary survey (a more detailed exam). Use your differential as a guide.


Armed with your clinical acumen and diagnostic skills, your first inclination is going to be to ask the patient your list of questions to rule-out the life threats. Refrain from doing this.

First of all, once you start asking questions, the answers you get will be biased in favor of the questions you are asking. You may not get the truth.

Secondly, the patient may not feel like they are listened to if you don’t allow them to talk. This is not only important so that patients feel satisified, but it also engenders a trusting relationship between you and your patient. They will feel it easier to share information with you.

Allow the patient to talk for 2 minutes without interruption. You will get the diagnosis most of the time this way. Most patients won’t require a full two minutes either. After two minutes, unless I’m getting valuable information, I’ll interupt to direct the patient on to the questions I have: questions related to the differential diagnosis I have made.

Some patients don’t like to talk and require you to prompt them from the start.


Your focused physical further refines your differential. If a patient is complaining of an ankle sprain, they don’t need a complete neurologic exam. They do need a good assessment of the foot’s neurovascular status and assessment for common disabling foot injuries. A patient with a headache, doesn’t need an ankle exam, but sure needs a good neuro assessment.

Assign Pretest Probabilities

At this point you have enough information to assign pretest probabilities to the diagnoses in your differential. Using your history and physical rate each disease process as no, low, medium or high probability. Those listed as “no” are ruled-out. Some diagnoses you can rule-in with your secondary survey. For the rest (low, medium, high), you may need some diagnostic tests to assist you.

Diagnostic Testing

Your history and physical allowed you to assign pretest probabilities to the diagnoses in your differential. These probabilities now guide your choice and interpretation of diagnostic testing. Order only what you need to help confirm or rule out your differentials. You shouldn’t order tests to form your differential.

Here is where your knowledge of the tests comes in to play. For example, a patient with a low pretest probability of pulmonary embolus plus a negative d-dimer essentially rules-out a PE.

Once you have the results of your tests, you can assign post-test probabilities. You may not have a definitive diagnosis at the end, but you’ll usually have a pretty good idea. Sometimes you’ll need to continue managing the patient without the diagnosis.

Also be sure to order everything you need at once, not piecemeal. It’s not very efficient when you order a CBC now, then a blood culture when that comes back positive, then a chest x-ray, then a urinalysis.

Treatment and Disposition

Treat the remaining disease (or diseases) on your differential accordingly. This includes decisions about admission versus discharge and follow-up.

Try to form your full treatment plan upon leaving the patient’s room. Avoid the common error of delaying thinking about your plan until labs come back. Instead, think about it now

For example, if acute coronary syndrome is part of your differential, you know you’ll be admitting the patient for a 23-hour rule out and stress test. This way you can get the process moving.

Or perhaps, your plan is to do serial exams on a child with belly pain. If the pain persists in an hour and he continues to vomit, you’ll get labs. If that’s abnormal and the pain persists, order a CT scan. If the pain is gone, send the patient home with “watch for appendicitis” instructions.


  1. indranil says:

    is interpretation of the diagnostic testing part of the initial survey…. like with primary survey we did one initial action ex- ECG for this patient with chest pain….

    1. Rahul Patwari says:

      Indranil, thanks for the comment. During the primary survey, you concentrate on what will kill them now. This is a quick clinical exam noting things that are immediately recognizable and treatable. There’s usually no diagnostic testing to check here.

      The initial actions also shouldn’t have much diagnostic testing (except in some circumstances an EKG or an accucheck). So, similarly there won’t be any testing to check, most of that comes after the secondary survey.

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