Emergency Department Design




In the United States, hospitals build new emergency departments (EDs) every 15 to 20 years. Renovations of existing EDs occur every 5 to 10 years. The main concerns of ED designers are providing efficient spaces for routine care, handling peak volumes, and anticipating future needs. Well-designed EDs accommodate daily, weekly, and seasonal tidal peaks and valleys in patient flow. The variety of high- and low-acuity illnesses and injuries requires EDs to prioritize care into critical, emergent, and urgent treatment. EDs meet community needs for specialized care by providing areas for unique care needs with pediatric, cardiac, trauma, geriatric, or stroke centers. Often only as a last thought do EDs include some design features for disaster and mass-casualty response. , In the wake of terror-related events, such as the Boston Marathon Bombing and the New York City World Trade Center disaster on September 11, 2001, and natural disasters, such as hurricanes Sandy and Katrina, more EDs are being designed or renovated to meet anticipated disaster needs. These designs and renovations include enhanced security, decontamination, and isolation, and addition of other specialized treatment areas, as well as expanding capacity to treat multiple victims within, or in proximity to, EDs.


When planning a new ED or a renovation, the following question should be added to the usual list of design questions: “How can the new ED better respond to disaster events?” ED designs should be planned for normal operations, as well as potential disaster events that could create increased demand and unique needs. One approach to better ED design for disaster is to organize a workshop early in the design process to address emergency preparedness, bringing together hospital administration, ED staff, other key employees, and security and community agencies to complete a risk assessment analysis. Better design can emerge from identifying potential disaster scenarios (e.g., hurricane, pandemic epidemic, or direct attack on the ED), rating their probability of occurrence (e.g., very likely, high, low, or very unlikely), and then listing the potential facility implications of each scenario.


Historical perspective


In the aftermath of terror events and natural disasters with subsequent disaster response planning, hospital architects have begun to design EDs to better meet the needs anticipated from a terror attack, flood, or epidemic. Some ED design lessons have been learned from disaster events. From the Tokyo Sarin event, recent natural disasters and epidemic illnesses, and other routine “disasters,” such as influenza outbreaks, hospitals know they need to plan for surge capacity. Methods of alerting and preparing ED staff early and protecting emergency care providers from contamination and infection are needed, a lesson integrated into current ED staff vaccination requirements and made painfully clear by the Tokyo Sarin event, in which many emergency providers were contaminated. The Boston Marathon Bombing event illustrated the need to provide emergency and surgical care to mass casualties, requiring coordination of response between hospitals and enhanced field rescue efforts to meet high volume demands over a short time period. In New York after 9/11, the cleanup phase after the event led to prolonged increased prehospital and ED volume. Most care was provided by emergency personnel working close to ground zero. From the anthrax mailings in the wake of the World Trade Center event, planners learned to anticipate the need for accurate public information and increased ED patient volume. From the flooding and evacuation of hospitals and EDs, with the needs for medical capacity met at new sites on high ground during Katrina, planners relearned the importance of providing care throughout a larger health care system, with each hospital and ED participating uniquely, some evacuating and relocating, and others providing care to surges of relocated and new patients.


The ED remains the most available point of access to immediate health care in the United States. ED designers are now anticipating increased volumes of patients that might be generated by a disaster, epidemic, or a terror event. Although a stressed public needs information and health screenings that perhaps can be met by providers outside the ED, the ED will be accessed for counseling and screening when other services are overwhelmed, critical information is misunderstood, or delay to access is anticipated or encountered. In most disaster scenarios, shelter needs are provided outside the ED. However, loss of facilities or needs for quarantine of exposed and ill patients during bioterror events and epidemics may create shelter needs proximate to EDs.


ED design and response capability after 9/11 became a larger concern for public disaster planners, the federal government, and hospital architects. Two federally funded projects coordinated by emergency physicians, one at Washington Hospital Center (ER One) and another at the Rhode Island Disaster Initiative (RIDI), have developed and released recommendations. ER One suggests designs for a new ED that meets any and all anticipated needs of a disaster event. RIDI has developed new disaster response paradigms, training scenarios, and response simulations that also can be used in ED design.


Recommendations of Project ER One


Scalability





  • Universal patient care rooms that are configurable for any purpose



  • Single patient rooms reconfigurable to accommodate up to three patients



  • Rapid conversion of nonpatient care space such as waiting rooms into clinical space for 4 to 5 times scalability



Alternate Care Sites





  • Modular and mobile solutions rather than dedicated built-in equipment



  • Convex multilane vehicular access



  • Emphasis on portability and modularity at every scale



  • Instant access to all data for any patient at any moment



  • Person-to-person communications net independent of other communications systems



Capability





  • All rooms with negative pressure capability and 100% nonrecirculated air



  • Every room an isolation room with separate ventilation and separate toilet facilities



  • Ability to isolate single rooms or entire zones and sectors



  • Multimode decontamination capability in every area of the facility



  • Portals for access control and threat detection



  • Universal docking capability for portable external modular treatment units



  • Robust real-time data sharing with local, state, and federal health authorities



Threat Mitigation





  • Self-decontamination surfaces



  • Offset parking away from building footprint



  • Single-room and single-zone modular compartmentalized ventilation systems



  • 100% air filtration



  • Assured water supply with internal purification capabilities



  • Blast-protection walls and blast-deflection strategies



  • Elimination or encapsulation of building materials that can shatter during an event



  • Built-in radiation protection



  • Advanced security and intrusion detection technologies





Current practice


An ED design using ER One concepts has been constructed at Tampa General Hospital in Florida. After considering highly likely disaster scenarios, specific recommendations were developed and integrated into the Tampa ED design. To address surge capacity, the State of Florida, the project architects, and hospital administration agreed on an ED that could expand from 77 treatment spaces to 210 within the ED. A parking area beneath the ED was designed to convert to a mass decontamination zone, feeding directly into the ED. The ED observation area was designed to convert into a quarantine unit, with direct access from outside the ED during epidemics. Adding these elements to create an ED that is more disaster ready increased the cost of the project by less than 5%. ED design would be tremendously enhanced if a prototype “disaster-ready” ED demonstrating all the elements of ER One could be built. To date no full prototype has been constructed, and it has yet to be shown that ED designers are able to create an “all-hazards-ready” ED, given financial constraints. However, incorporating some disaster-ready suggestions when EDs are built or renovated will improve our readiness and may be more financially feasible. New building materials, technologies, and concepts will continue to inform the effort to prepare EDs for terror attack. Urban ED trauma centers are attempting to develop the capacity to serve as regional disaster resource centers and the capability for site response to disaster events. These EDs are designed to incorporate larger waiting and entrance areas, adjacent units, or nearby parking spaces in their plans to ramp-up treatment capacity. More decontamination and isolation capacity is being built to help control the spread of toxic or infectious agents.


Information systems are being made available to provide real-time point-of-service information and any needed “just-in-time” training for potential terror threats. An example of better organized disaster information is the CO-S-TR model, a tool for hospital incident command that prioritizes action to address key components of surge capacity. There are three major elements in the tool, each with four subelements. “CO” stands for command, control, communications, and coordination and ensures that an incident management structure is implemented. “S” considers the logistical requirements for staff, stuff, space, and special (event-specific) considerations. “TR” comprises tracking, triage, treatment, and transportation. Having an information system with robust capability to gather and display the detailed information needed in a preformatted and rehearsed mode such as CO-S-TR, with easy access by multiple electronic means, including wireless and handheld devices, is an important facility design feature.


The technology needed to respond to a terrorist event, such as personal protective equipment (PPE), is becoming more widely available and is stored where it is easily available in EDs. Although mass decontamination can and in general should occur close to the disaster scene, EDs are gearing up to better decontaminate, isolate, and treat individuals or groups contaminated with biologic or chemical materials upon arrival. The Tokyo Sarin episode demonstrated clearly that contaminated patients will make their way to the ED without waiting for first responders. Four elements of ED design are being addressed to prepare EDs for terror events: scalability, security, information systems, and decontamination.


Scalability, Surge, and Treatment Capacity


EDs are generally designed with sufficient, but not excess, space. The number of treatment spaces needed in an ED is usually matched to the anticipated ED patient volume; roughly 1 treatment space per 1100 annual ED visits or 1 treatment space per 400 annual ED hospital admissions is recommended. According to disaster planners, a major urban trauma center ED built for 50,000 to 100,000 visits per year should have surge capacity up to 100 patients per hour for 4 hours and 1000 patients per day for 4 days. One disaster-ready design challenge is to provide surge capacity to meet anticipated patient needs. Hospitals are woefully overcrowded, and EDs are routinely housing admitted patients. To maintain surge capacity, efforts to address hospital overcrowding and eliminate the boarding of admissions in the ED must be successful.


EDs are now being designed to allow growth into adjacent space: a ground level or upper level, a garage, or a parking lot. Garage and parking lot space has been used in many disaster drills and mass exposures. Garages and parking lots can be designed with separate access to streets, allowing separation of disaster traffic and routine ED traffic. More often, needed terror-response supplies (e.g., antidotes, respirators, personal protective gear) are stored near or within the ED. The cost of ventilation, heat, air conditioning, communication, and security features often prohibits renovation of garages. More often, tents are erected over parking lots or loading areas. Modular “second EDs,” tents or structures with collapsible walls (fold and stack), have been deployed by disaster responders. These can be used near the main ED, preserving the ED for critical cases during a disaster surge. Some hospitals are building capacity for beds in halls and double capacity patient rooms, and converting other nontreatment spaces to wards to increase their ability to meet patient surges during disaster. Hallways can provide usable space if constructed wider and equipped with medical gases and adequate power and lighting. Often only minimal modifications are necessary to make existing halls and lobbies dual-use spaces. Some hospitals have increased space by installing retractable awnings on the exterior over ambulance bays or loading docks. Tents are often used outside EDs as decontamination and treatment areas in disaster drills. Tents with inflatable air walls have the added benefit of being insulated for all-weather use.


In the military, the need to provide treatment in limited space has resulted in the practice of stacking patients vertically to save space and to reduce the distances that personnel walk. U.S. Air Force air evacuation flights have stacked critical patients three high, and some naval vessels may bunk patients vertically in mass-casualty scenarios. Similar bed units could be deployed for a mass event. Portable modular units are also available to help EDs meet additional space needs. Unfortunately, many EDs plan to rely on other facilities in the regional system and do not build in surge capacity. During a terror event occurring on a hospital campus, the ED function may need to be moved to a remote area within the hospital in response to a flood, fire, building collapse, bomb or bomb threat, active shooter, or other event. Many disaster plans designate a preexisting structure on campus as the “backup” ED. The area is stockpiled with equipment and has a viable plan for access. Patient and staff movement are planned and developed during drills.


In addition to increasing ED surge capacity, significant off-loading of ED volume can be accomplished by “reverse triage” of inpatients. Through such measures as delaying elective admissions and surgeries, early discharge, or interhospital transfer of stable patients, significant improvements in bed capacity can be accomplished within hours. ,


Although the capacity to handle patient surges is being addressed regionally and nationally, large events with high critical care volumes will overtax the system regionally, as was the case during Hurricane Katrina. The National Disaster Medical System (NDMS) can be mobilized to move excess victims and establish field hospitals during events involving hundreds or thousands of victims. However, there are barriers to a prompt response time in the deployment of NDMS resources.


The ED plan to provide treatment during disaster must include evacuation, since the event may produce an environmental hazard that contaminates, floods, or renders the ED inaccessible. Evacuation of ED patients has been addressed by ED designers. Some EDs have the capacity to more easily evacuate. In well-planned EDs, stairwells have floor lights to assist in darkness. Stairways are sufficient in size to allow backboarded and chair-bound patients to be evacuated. Ground level EDs should have access to surface streets, interior pathways, and exterior sidewalks. The communication and tracking system includes sensors in corridors and stairways. Patient records are regularly backed up and stored for web access and hence available during and after evacuation. Specially designed ambulance buses allow for the safe transfer of multiple patients of variable acuity to other facilities.


Security


Securing the function of an ED includes securing essential resources: water, gases, power, ventilation, communication, and information. ED security involves surveillance, control of access and egress, threat mitigation, and “lockdown” capacity. Surveillance exists in almost all EDs. Many ED parking and decontamination areas are monitored by cameras. The wireless tracking system can also be part of the surveillance system. A tracking system can create a virtual geospatial and temporal map of staff and patient movement. Tracking systems have been used in disaster drills to identify threat patterns. Most EDs have identification/access cards and readers. Chemical and biologic sensors for explosives, organic solvents, and biologic agents are becoming available, but have not been used in EDs. Many EDs have metal detectors and security checkpoints prior to access by ambulatory patients and visitors. When selecting a sensor, designers consider sensitivity, selectivity, speed of response, and robustness. Sensor technology is an area of active research that continues to yield new solutions that could be incorporated into ED security. In concept, all entrances could be designed to identify persons using scanning to detect unwanted chemicals, biologic agents, or explosives, allowing detention and decontamination when needed. Given the wide array of physicochemical properties of hazardous materials in commerce, developing sensors with sufficient sensitivity to detect threats while avoiding an excess of false positives will remain a challenge.


Most EDs have multiple entry portals for ingress of patients, visitors, staff, vendors, law enforcement personnel, and others. EDs are using screening and identification technologies at all entrances in combination with closed-circuit video monitoring. Personnel must be dedicated for prompt response when needed. Automation of identification can efficiently allow safe flow of patients, staff, and supplies. Vehicle access has been managed by bar-coding staff and visitor vehicles. At some road access points, automated scanners could monitor and control vehicle access. Modern EDs limit the number of entrances and channel pedestrian and vehicular traffic through identification control points. For the most part, points of entrance into the ED can be managed with locking doors, identification badge control points, and surveillance to allow desired access for staff and supplies. Thoughtful planning should facilitate rapid access between the functional areas, such as the ED, operating rooms, catheterization suites, and critical care units. Movement within and between buildings needs to be controlled and must allow a total lockdown when necessary.


Direct threats to the ED include blasts; chemical, biologic, and environmental contamination; and active shooting. There are several strategies to mitigate blasts. Twelve-inch-thick conventional concrete walls, using commercially available aggregates (147 lb per cubic foot), afford reasonable blast protection. , On some campuses, the space between the ED and the entrance is designed largely to prevent direct attack. However, atriums are terror targets. Although atriums are useful as overflow areas, their windows and glass can create hazardous flying debris. In general, use of unreinforced glass windows, which help create a more pleasant ED environment, must be balanced against threat of injury from broken glass shards. Given the threat of blast attack, communication, gas, electric, water, and other critical services should be remote from vulnerable areas and shielded when they traverse roads and walkways. Protection against release of chemical and biologic agents inside or outside the ED requires a protective envelope, controlled air filtration in and out, an air distribution system providing clean pressurized air, a water purification system providing potable water, and a detection system. Better HVAC systems can pressurize their envelope, keeping contaminants out, and also purge contaminated areas.


Information


Anticipated computing needs for ED operations during disaster events are immense. In most EDs, large amounts of complex and diverse information are routinely available electronically. Overflow patients in hallways and adjacent spaces can be managed with mobile computing, which is available in many EDs. Wireless handheld devices can facilitate preparation for disasters and allow immediate access to information by providers in hallways and decontamination spaces. Multiple desktop and mobile workstations are available throughout most EDs. During disaster, displays of information that will aid decision making include bed status, the types of rooms available, the number of persons waiting, and ambulances coming in. Monitors now display patient vital signs, telemetry, and test results. Significant improvements in efficiency and decision making can be achieved when more real-time information is available to decision makers. Having available multiple computer screens with preformatted disaster information screens that are regularly used should enhance ED readiness.


Clinical decision tools and references, such as UpToDate, make information readily available to providers. These and other just-in-time resources will be needed when practitioners treat unusual or rare diseases not encountered in routine practice. The wide variety of potential disaster scenarios argues for the availability of just-in-time information. Information specific to a disaster event should be broadcast widely on multiple screens in many areas. Cellular links and wireless portable devices should also be designed to receive and display disaster information. Access to information has been enhanced in most EDs through cell phone, texting, and other social media use. Developing apps to make local disaster information available through as many media as possible and to guide each staff member should be part of the information system disaster plan.


Diagnostic decision support systems have been demonstrated to help practitioners recognize symptom complexes that are uncommon or unfamiliar. Information systems should be capable of communicating potential terror event information regularly. Many EDs have log-on systems that require staff to read new information. In a disaster-ready ED, a list of potential threats could be posted daily. However, the utility of computer references or on-call experts is limited by the practitioner’s ability to recognize a situation that requires the resource.


Computer-based patient tracking systems are available for routinely tracking patients in most EDs. Some computer-based tracking systems have a disaster mode that quickly adapts to a large influx of patients allowing for collation of symptoms, laboratory values, and other pertinent syndromic data. In many regions, EDs provide real-time data that serve as a disaster alert surveillance network. Routine data obtained on entry are passively collected and transferred to a central point for analysis (usually a health department). In the event of a significant spike in targeted patient symptom complexes, these data can trigger an appropriate disaster response. The capacity for this entry point surveillance should be anticipated and built in to any disaster-ready ED information system. For example, data terminals allowing patients to input data at registration similar to electronic ticketing at airports could passively provide information during a surge, rather than requiring chief complaint and registration data input by staff. This self-service system could add to ED surge capacity. Similarly, real-time bed identification, availability, and reservation systems used to assist patient management in some EDs could aid ED function during disaster. Movement to an inpatient bed is a well-documented choke point recognized nationally during normal hospital operations, and implementing a plan to open access to admissions becomes an issue during disaster.


Lobby screens can facilitate family access to information during a disaster, displaying information about the event and patient status using coded names to preserve confidentiality. During disasters, family members can be given their family member’s coded name and access to screens to query for medical information. Computers with Internet access that could display public event information are available in patient rooms in some EDs.


During anthrax mailings, public hysteria taxed the health care system. Posttraumatic stress, anxiety, and public concern over possible exposure to a biologic or chemical agent may generate a surge of minor patients at EDs. Within some EDs, lecture halls or media centers are available; they are generally used for teaching conferences but could provide venues for health information and media briefings during disaster. The media are an important source of public information and must be considered when planning disaster response. An adjacent conference area can serve as a media center, where information could be released to the Internet and closed-circuit screens could provide more accurate information to allay public concerns and direct the public to appropriate resources and access points for evaluation of potential exposures. Poison control centers provide an immediate source of valuable information for hazard communication and risk assessment.


Notwithstanding the tremendous potential value of computer systems in disaster management, it is important to anticipate and plan for information systems and communications failure. Failure of hospital generators, such as occurred in Hurricane Sandy, will rapidly render computers and landline telephones inoperable. Cellular telephone services are often overwhelmed during disasters. The Internet appears to be less likely to crash during disasters, due to its redundancy, but hospitals should plan for alternative methods of communication and documentation.


Isolation and Decontamination


Many EDs have patient decontamination (DECON) areas. Adequate environmental protection for patients undergoing DECON is necessary and includes visual barriers from onlookers, segregation of the sexes, and attention to personal belongings. , In many EDs, DECON areas are being added to accommodate mass exposures. EDs have added or augmented DECON facilities. DECON areas should have a separate, self-contained drainage system, controlled water temperature, and shielding from environmental hazards. Exhaust fans are used to prevent the buildup of toxic off-gassing in these decontamination areas. Most importantly, DECON facilities should be deployable within minutes of an incident, to avoid secondary contamination of the ED. For most EDs, mass DECON has been accomplished by using an uncovered parking lot and deploying heated and vented modular tent units. Uncovered parking areas adjacent and accessible to the ED have been enabled for disaster response. Other EDs use high-volume, low-pressure showers mounted on the side of a building. Serial showers allow multiple patients to enter at the same entrance and time. However, serial showers do not provide privacy, can be difficult for an ill patient to access, and can lead to contaminated water runoff. Also, persons requiring more time may impede flow and reduce the number of patients decontaminated. Parallel showers built in advance or set up temporarily in tenting offer greater privacy but require wider space and depth. Combined serial and parallel design allows the advantages of each, separating ill patients and increasing the number of simultaneous decontaminations.


Often built into the ED is another DECON room for one or two patients with the following features: outside access; negative pressure exhaust air exchange; water drainage; water recess; seamless floor; impervious, slip-resistant, washable floor, walls, and ceiling; gas appliances; supplied air wall outlets for PPE use; high-input air; intercom; overhead paging; and an anteroom for DECON of isolated cases. PPE is routinely used by military and fire departments during events involving hazardous materials. Hospitals likewise must be trained for and plan to use these devices and store a reasonable number of protective ensembles (i.e., gloves, suits, and respiratory equipment), usually near the ED DECON area. DECON areas are built with multiple supplied air outlets for PPE use to optimize safety and maximize work flexibility.


Powered air purifying respirators (PAPRs) are used by many hospitals in lieu of air supplied respirators. While providing increased mobility and convenience, their utility is somewhat limited by the requirement for battery power and the need to select an appropriate filtration cartridge. Voice-controlled two-way radios facilitate communication among DECON staff with receivers in the ED. A nearby changing area is available in some EDs. The changing area is laid out to optimize medical monitoring and to ease access to the DECON area. The need for easily accessible PPE and adequate training and practice in the use of PPE cannot be overemphasized.


Some capability to isolate and prevent propagation of a potential biologic agent has been designed into most EDs. Patients who present with undetermined respiratory illnesses are routinely sent to an isolation area. A direct entrance from the exterior to an isolation room is not usually available but has been a recent renovation in some EDs. Creation of isolation areas poses special design requirements for HVAC, cleaning, and security to ensure that infections and infected persons are contained. An isolation area should have compartmentalized air handling with high-efficiency filters providing clean air. Biohazard contamination is particularly difficult to mitigate. Keeping the facility “clean” and safe for other patients is an extreme challenge. Biologic agents of terrorism or epidemics may resist decontamination attempts. Infected patients present a risk to staff. During the severe acute respiratory syndrome (SARS) epidemic, Singapore built outdoor tent hospitals to supplement their existing decontamination facility. Patients were evaluated outside the ED and those with fever were isolated and not allowed to enter the main hospital. This, among other measures, allowed Singapore to achieve relatively rapid control over the epidemic. Few triage areas and ED rooms have been designed for decontamination. Surfaces must be able to withstand repeated decontamination. Sealed inlets for gases and plumbing have also been considered. Patients who are isolated can be observed with monitoring cameras. Some isolation areas include a restroom within their space, which helps restrict patient egress.


All ED areas could have more infection control capabilities built in. Floor drains have been included in some ED rooms for easier decontamination. Infection control is improved using polymer surface coatings that are smooth, nonporous, and tolerant to repeated cleaning, creating a virtually seamless surface that is easy to clean. These coatings can be impregnated with antimicrobial properties, enhancing their biosafe capability. Silver-impregnated metal surfaces in sinks, drains, door handles, and other locations can reduce high bacterial content. Silver-impregnated metal has demonstrated antimicrobial effects.


Conventional ventilation systems use 15% to 25% outside air during normal operation, thus purging indoor contaminants. Air cleaning depends on filtration, ultraviolet irradiation, and purging. HVAC design should model demand for adequately clean air and also for isolation of potential contaminants. The disaster-ready ED requires protection from external contaminations as well as contagious patients. A compartmentalized central venting system without recirculation has the ability to remove or contain toxic agents in and around the ED. Compartmentalized HVAC systems allow for the sealing of zones from each other. More desirable HVAC systems electronically shut down sections, use effective filtration, and can clean contaminated air. A compartmentalized system can fail, but it only fails in the zone it is servicing; smaller zones mean smaller areas lost to contamination. These systems are less vulnerable to global failure or spread of contamination. Modular mobile HVAC units developed for field military applications have been added to existing ED isolation areas for use when needed to create safe air compartments.

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Aug 25, 2019 | Posted by in EMERGENCY MEDICINE | Comments Off on Emergency Department Design

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