emergency department emergency department an emergency department (ed), also known as an accident and emergency department (a&e), emergency room (er), emergency ward (ew) or casualty department, is a medical treatment facility specializing in emergency medicine, the acute care of patients who present without prior appointment; either by their own means or by that of an ambulance. the emergency department is usually found in a hospital or other primary care center. "resus" redirects here. not to be confused with rhesus or cardiopulmonary resuscitation. the main patient area inside the mobile medical unit operated in belle chasse, louisiana due to the unplanned nature of patient attendance, the department must provide initial treatment for a broad spectrum of illnesses and injuries, some of which may be life-threatening and require immediate attention. in some countries, emergency departments have become important entry points for those without other means of access to medical care. the emergency departments of most hospitals operate 24 hours a day, although staffing levels may be varied in an attempt to reflect patient volume. history accident services were provided by workmen's compensation plans, railway companies, and municipalities in europe and the united states by the late mid-nineteenth century, but the world's first specialized trauma care center was opened in 1911 in the united states at the university of louisville hospital in louisville, kentucky. it was further developed in the 1930s by surgeon arnold griswold, who also equipped police and fire vehicles with medical supplies and trained officers to give emergency care while en route to the hospital. today, a typical hospital has its emergency department in its own section of the ground floor of the grounds, with its own dedicated entrance. as patients can arrive at any time and with any complaint, a key part of the operation of an emergency department is the prioritization of cases based on clinical need. this process is called triage. triage is normally the first stage the patient passes through, and consists of a brief assessment, including a set of vital signs, and the assignment of a "chief complaint" (e.g. chest pain, abdominal pain, difficulty breathing, etc.). most emergency departments have a dedicated area for this process to take place and may have staff dedicated to performing nothing but a triage role. in most departments, this role is fulfilled by a triage nurse, although dependent on training levels in the country and area, other health care professionals may perform the triage sorting, including paramedics and physicians. triage is typically conducted face-to-face when the patient presents, or a form of triage may be conducted via radio with an ambulance crew; in this method, the paramedics will call the hospital's triage center with a short update about an incoming patient, who will then be triaged to the appropriate level of care. most patients will be initially assessed at triage and then passed to another area of the department, or another area of the hospital, with their waiting time determined by their clinical need. however, some patients may complete their treatment at the triage stage, for instance, if the condition is very minor and can be treated quickly, if only advice is required, or if the emergency department is not a suitable point of care for the patient. conversely, patients with evidently serious conditions, such as cardiac arrest, will bypass triage altogether and move straight to the appropriate part of the department. the resuscitation area, commonly referred to as "trauma" or "resus", is a key area in most departments. the most seriously ill or injured patients will be dealt with in this area, as it contains the equipment and staff required for dealing with immediately life-threatening illnesses and injuries. in such situations, the time in which the patient is treated is crucial. typical resuscitation staffing involves at least one attending physician, and at least one and usually two nurses with trauma and advanced cardiac life support training. these personnel may be assigned to the resuscitation area for the entirety of the shift or may be "on call" for resuscitation coverage (i.e. if a critical case presents via walk-in triage or ambulance, the team will be paged to the resuscitation area to deal with the case immediately). resuscitation cases may also be attended by residents, radiographers, ambulance personnel, respiratory therapists, hospital pharmacists and students of any of these professions depending upon the skill mix needed for any given case and whether or not the hospital provides teaching services. patients who exhibit signs of being seriously ill but are not in immediate danger of life or limb will be triaged to "acute care" or "majors", where they will be seen by a physician and receive a more thorough assessment and treatment. examples of "majors" include chest pain, difficulty breathing, abdominal pain and neurological complaints. advanced diagnostic testing may be conducted at this stage, including laboratory testing of blood and/or urine, ultrasonography, ct or mri scanning. medications appropriate to manage the patient's condition will also be given. depending on underlying causes of the patient's chief complaint, he or she may be discharged home from this area or admitted to the hospital for further treatment. patients whose condition is not immediately life-threatening will be sent to an area suitable to deal with them, and these areas might typically be termed as a prompt care or minors area. such patients may still have been found to have significant problems, including fractures, dislocations, and lacerations requiring suturing. children can present particular challenges in treatment. some departments have dedicated pediatrics areas, and some departments employ a play therapist whose job is to put children at ease to reduce the anxiety caused by visiting the emergency department, as well as provide distraction therapy for simple procedures. many hospitals have a separate area for evaluation of psychiatric problems. these are often staffed by psychiatrists and mental health nurses and social workers. there is typically at least one room for people who are actively a risk to themselves or others (e.g. suicidal). fast decisions on life-and-death cases are critical in hospital emergency departments. as a result, doctors face great pressures to overtest and overtreat. the fear of missing something often leads to extra blood tests and imaging scans for what may be harmless chest pains, run-of-the-mill head bumps, and non-threatening stomach aches, with a high cost on the health care system. nomenclature in english emergency department became commonly used when emergency medicine was recognized as a medical specialty, and hospitals and medical centres developed departments of emergency medicine to provide services. other common variations include 'emergency ward', 'emergency centre' or 'emergency unit'. accident and emergency (a&e) is deprecated in the united kingdom but still in common parlance. it is also still in use in hong kong. earlier terms such as 'casualty' or 'casualty department' were previously used officially and continue to be used informally. the same applies to 'emergency room', 'emerg', or 'er' in north america, originating when emergency facilities were provided in a single room of the hospital by the department of surgery. signage regardless of naming convention, there is a widespread usage of directional signage in white text on a red background across the world, which indicates the location of the emergency department, or a hospital with such facilities. signs on emergency departments may contain additional information. in some american states, there is close regulation of the design and content of such signs. for example, california requires wording such as "comprehensive emergency medical service" and "physician on duty", to prevent persons in need of critical care from presenting to facilities that are not fully equipped and staffed. in some countries, including the united states and canada, a smaller facility that may provide assistance in medical emergencies is known as a clinic. larger communities often have walk-in clinics where people with medical problems that would not be considered serious enough to warrant an emergency department visit can be seen. these clinics often do not operate on a 24-hour basis. very large clinics may operate as "free-standing emergency centres", which are open 24 hours and can manage a very large number of conditions. however, if a patient presents to a free-standing clinic with a condition requiring hospital admission, he or she must be transferred to an actual hospital, as these facilities do not have the capability to provide inpatient care. examples of emergency department signage santa clara valley medical center mayo clinic hospital in rochester trilingual signage in french, dutch and english at an emergency department in brussels, belgium united states the centers for medicare and medicaid services (cms) classified emergency departments into two types: type a, the majority, which are open 24 hours a day, 7 days a week, 365 days a year; and those who are not, type b. many us emergency departments are exceedingly busy. a study found that in 2009, there were an estimated 128,885,040 ed encounters in us hospitals. approximately one-fifth of ed visits in 2010 were for patients under the age of 18 years. in 2009–2010, a total of 19.6 million emergency department visits in the united states were made by persons aged 65 and over. most encounters (82.8 percent) resulted in treatment and release; 17.2 percent were admitted to inpatient care. the 1986 emergency medical treatment and active labor act is an act of the united states congress, that requires emergency departments, if the associated hospital receives payments from medicare, to provide appropriate medical examination and emergency treatment to all individuals seeking treatment for a medical condition, regardless of citizenship, legal status, or ability to pay. like an unfunded mandate, there are no reimbursement provisions. rates of ed visits rose between 2006 and 2011 for almost every patient characteristic and location. the total rate of ed visits increased 4.5% in that time. however, the rate of visits for patients under one year of age declined 8.3%. a survey of new york area doctors in february 2007 found that injuries and even deaths have been caused by excessive waits for hospital beds by ed patients. a 2005 patient survey found an average ed wait time from 2.3 hours in iowa to 5.0 hours in arizona. one inspection of los angeles area hospitals by congressional staff found the eds operating at an average of 116% of capacity (meaning there were more patients than available treatment spaces) with insufficient beds to accommodate victims of a terrorist attack the size of the 2004 madrid train bombings. three of the five level i trauma centres were on "diversion", meaning ambulances with all but the most severely injured patients were being directed elsewhere because the ed could not safely accommodate any more patients. this controversial practice was banned in massachusetts (except for major incidents, such as a fire in the ed), effective 1 january 2009; in response, hospitals have devoted more staff to the ed at peak times and moved some elective procedures to non-peak times. in 2009, there were 1,800 eds in the country. in 2011, about 421 out of every 1,000 people in the united states visited the emergency department; five times as many were discharged as were admitted. rural areas are the highest rate of ed visits (502 per 1,000 population) and large metro counties had the lowest (319 visits per 1,000 population). by region, the midwest had the highest rate of ed visits (460 per 1,000 population) and western states had the lowest (321 visits per 1,000 population). most common reasons for discharged emergency department visits in the united states, 2011 age (in years)reason for visitvisits <1fever of unknown origin270,000 1–17superficial injury, contusion1.6 million 18–44sprains and strains3.2 million 45–64nonspecific chest pain1.5 million 65–84nonspecific chest pain643,000 85+superficial injury, contusion213,000 freestanding in addition to the normal hospital based emergency departments a trend has developed in some states (including texas and colorado) of emergency departments not attached to hospitals. these new emergency departments are referred to as free standing emergency departments. the rationale for these operations is the ability to operate outside of hospital policies that may lead to increased wait times and reduced patient satisfaction. these departments have attracted controversy due to consumer confusion around their prices and insurance coverage. in 2017, the largest operator, adeptus health, declared bankruptcy. overuse and utilization management patients may visit the emergency room for non-emergencies, which typically costs the patient and the managed care insurance company more, and