Differences Between the Emergency Department, the Office, and the Inpatient Setting

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This chapter was reproduced from the Emergency Medicine Clerkship Primer, 2008, Chapter 5, with the permission of the Editor, for ease of viewing on mobile devices.


Throughout medical school, you will encounter patients in many clinical arenas: the inpatient wards, the public health clinic, the private office, the hospital outpatient clinic, and of course the emergency department. Although medicine at its core involves taking care of patients, the approach and sequence of steps involved in caring for patients will be different depending on the health care setting in which they are encountered. When evaluating a patient, the health care provider (nurse, medical student, resident, or attending) needs to develop an approach tailored to the specific health care setting and available resources.

Think of the ambulatory care and hospital outpatient clinic setting. In this clinical venue, unexpected emergencies occur; however, they are few and far between. The acuity level is low, with 1% of patient encounters requiring referral to the emergency department or for hospital admission (Middleton et al., 2007, Cherry et al., 2007). Some patients will require diagnostic studies (laboratory tests or diagnostic imaging). Fortunately in this setting, the majority of these are routine, and most are obtained electively.

Many patients requiring diagnostic studies will need to be referred to an off-site laboratory, diagnostic imaging center, or hospital to undergo testing. Therefore, the results of many of these diagnostic studies are not available to the ordering physician for days. Although many private offices and outpatient clinics have a system in place allowing unscheduled walk-in visits, the overwhelming majority of patient visits are scheduled, and patients are cared for on a first-come-first-served basis. When patients are sick, or when the office is closed, patients are referred to the emergency department. In addition, the majority of patients seeking medical care in an ambulatory care or outpatient clinic setting are established patients compared with the emergency department, where the overwhelming number of physician–patient encounters are new visits.

Case Study

Consider the patient with an elevated blood pressure measurement who is referred to the emergency department for evaluation from a local health clinic. The patient is asymptomatic, without complaints of headache, chest pain, or shortness of breath. His repeat blood pressure measurement in the emergency department is 186/98 mmHg. In such a case, a targeted H&PE and selected diagnostic work up will be needed to exclude any acute complications of elevated blood pressure such as the involvement of key target organs (i.e., eyes, brain, heart, lungs, and kidneys). The goal is not necessarily to establish baseline laboratory values, to obtain diagnostic studies for future comparison or even to necessarily normalize the blood pressure at this time.

Traditionally, approximately half of all outpatient encounters are made to primary care physicians, with many of these visits being for preventive care. The most common reasons for a patient to visit an outpatient clinic include progress visit, general medical examination, routine prenatal care, cough, and sore throat. Together, these types of patient visits account for 20% of all outpatient clinic visits (Middleton et al., 2007). By contrast, the emergency department provides care to the acutely ill or injured. In the emergency department, nursing triage guidelines are designed to ensure that more seriously ill patients are cared for first. The acuity level is also much greater than the ambulatory care or outpatient clinic setting.

Across the country, approximately 12% of all emergency department patient encounters require hospital admission (Nawar et al., 2007), with 16% of patients admitted to a critical care bed. Anecdotally, high-acuity, high-volume emergency departments will admit 20% to 25% of cases to the hospital. Compared with the outpatient setting, a greater number of emergency department patient encounters require a diagnostic workup. This may include laboratory tests or advanced imaging techniques such as CT scans and magnetic resonance imaging (MITI). The majority of diagnostic tests performed in the emergency department by design provide results to the ordering physician within minutes to hours. Although some patients will present to the emergency department with complaints that could otherwise be cared for in an ambulatory care setting, many unexpected emergencies such as trauma, myocardial infarction, stroke, pneumonia, anaphylaxis, and others come through the doors at all hours of the day and night. Some of these cases require emergency subspecialty consultation, a service that is often difficult to provide in an ambulatory care setting.

In addition, the emergency department has both an ethical and legal obligation to evaluate every patient who presents for care to determine whether he or she has a medical emergency, regardless of ability to pay for health care (Emergency Medical Treatment and Active Labor Act or EMTALA). One third of the nation’s emergency departments are considered high safety net sites. These institutions serve a disproportionately high number of Medicaid and uninsured patients, a dramatically different payer mix than that of the routine ambulatory care population.

In the inpatient setting, patient encounters often occur after a preliminary or definitive diagnosis has been made by another health care provider, many times by the emergency physician. Across the country, emergency departments are responsible for approximately 55% of all hospital admissions (Owens et al., 2006). Physicians caring for inpatients face legitimate challenges, some diagnostic, others therapeutic or social, such as short- or long-term placement issues. We all know that medical emergencies occur in the inpatient population; luckily they are not as common as in the emergency department. When they do occur, the health care team often has the benefit of prior rapport with the patient and family, along with some understanding of the patient’s medical condition before the event at hand. This is in stark contrast to unexpected emergencies that present to the emergency department requiring prompt resuscitation and stabilization without the benefit of an adequate history of present illness (HPI) or knowledge of the patient’s medical history, prenatal care, medications, and the like.

The emergency department also differs dramatically from both the inpatient and ambulatory care setting in a few other areas. First and foremost, the emergency department never closes, and the volume of patients cared for is not limited by the number of patient care spaces. Although it is foreseeable that patients with nonurgent complaints will need to wait until an appropriate patient care area is available before they will be evaluated, the sick or unexpected emergencies are at times cared for in less-than-optimal patient care areas, such as a hallway. In the emergency department, the spectrum of patients ranges from the young to the very old, representing disease states of the newborn to the various complications seen in the elderly nursing home resident. The clinical scenarios encountered are also unique to this setting and can range from routine medical and surgical pathology to environmental emergencies, toxic exposures, substance abuse, trauma, psychiatric emergencies, and more.

It is also necessary to realize that patient-specific goals are different in the emergency department from other health care settings. This can directly translate into a better understanding of the specialty-specific approach to a particular clinical scenario or chief complaint. Understanding how emergency physicians approach particular clinical problems will allow students to better place the educational and patient care objectives of their rotation in perspective. See the case study shown in this chapter an example.

Focusing on the problem at hand is key to managing most cases in the emergency department. Whether we are talking about a complaint-directed H&PE, case presentation skills, or a case-specific differential diagnosis, the art of focusing—that is, being able to see the forest through the trees, identifying and relaying pertinent positive or negative case specific information—is crucial to understanding the role of the emergency physician and providing excellent patient care. Remember, the focus of the emergency department is different from other health care settings. Therefore, your approach to certain chief complaints or patient presentations may need to be modified to keep in line with providing optimal and efficient care in the emergency department.

Comparison of the Three Patient Care Settings
Emergency DepartmentInpatient SettingOffice/Outpatient Setting
Low–moderate-high acuity


12% of patients require hospital admission

Undifferentiated patients with complaint-based presentations

No prior rapport with patient and family

Most diagnostic studies ordered are urgent or emergent

Results of diagnostic studies available within minutes to hours

No scheduled visits; patients are evaluated in order of acuity

Low–moderate acuity



Admitted patients have a preliminary diagnosis

After initial evaluation, will develop rapport with patient and family

Diagnostic studies ordered can be nonurgent, urgent, or emergent

Results of diagnostic studies available within hours to days

Most admissions are unscheduled

Low acuity


1% of patients require hospital admission

Routine medical and follow-up care account for a majority of patient visits

Usually have established rapport with patient and family

Most diagnostic studies ordered are nonurgent

Results of diagnostic studies available within days

Scheduled visits on a first-come-first-served basis, occasional unscheduled visits

One final point that deserves mentioning is that the patient presenting to the emergency department must be considered at higher risk for potential serious illness than a similar patient presenting to an office or other outpatient clinic setting. Many patients presenting to the emergency department have acute symptoms. These complaints may reflect more serious underlying pathology when compared with the patient who is willing or able to wait several days for an outpatient appointment. In addition, patients choosing to come to an emergency department for an evaluation rather than going to an outpatient office should alert the caregiver that the patient may believe he or she is too sick to wait for a scheduled appointment; at times, they are right.

Thus, patient care in the emergency department is quite different from other health care settings. It is important to be aware of these differences so that, as a medical student, you understand that the clinical and bedside skills needed to succeed in the emergency department are different from skills needed to succeed in other settings. Understanding and embracing these differences will allow for a more educational and enjoyable experience.


Suggested Reading

  • Cherry DK, Woodwell DA, Rechtsteiner EA. National Ambulatory Medical Care Survey: 2005 summary. Advance Data From Vital Health and Statistics. 2007,387;1–40. Available at: http://www.cdc.gov/nchs/data/ad/ ad387.pdf. Accessed March 25, 2008.
    • This article reviews nationally representative data on ambulatory care visits in the United States. Data are from the 2005 National Ambulatory Medical Care Survey (NAMCS).
  • Middleton K, Hing E, Xu J. National Hospital Ambulatory Medical Care Survey: 2005 outpatient department summary. Advance Data From Vi-tal Health and Statistics. 2007,389;1–35. Available at: http://www.cdc.gov/nchs/ data/ad/ad389.pdf. Accessed March 25, 2008.
    • This article reviews nationally representative data on ambulatory care visits in the United States. Data are from the 2005 National Hospital Ambulatory Medical Care Survey (NHAMCS).
  • Owens P, Elixhauser A. Hospital Admissions That Began in the Emergency Department, 2003. Rockville, MD: Healthcare Cost and Utilization Project, Agency for Healthcare Quality and Research; 2006. Available at: http://www.hcup-us.ahrq.gov/reports/statbriefs/sb1.pdf. Accessed March 25, 2008.
    • This document uses data from the Healthcare Cost and Utilization Project to identify hospital admissions that began in the emergency department.