Disaster Preparedness

Published on 15/05/2015 by admin

Filed under Emergency Medicine

Last modified 15/05/2015

Print this page

This article have been viewed 3198 times

Chapter 193

Disaster Preparedness

Carl H. Schultz and Kristi L. Koenig

Perspective

Disasters occur in all areas of the world and cause harm to people, property, infrastructures, economies, and the environment. Harm to people includes death, injury, disease, malnutrition, and psychological stress. Recent catastrophes include earthquakes in Pakistan (2005) and Haiti (2010) (Fig. 193-1); devastating tsunamis in the Indian Ocean (2004) and Japan (2011); massive hurricanes in the southern United States (2005); severe flooding in Australia (2011); tornadoes in Arkansas, Tennessee, and Kentucky (2008); and unusual weather conditions producing record snowfalls in the United States and Europe (2011). Increasing population density in floodplains and in earthquake- and hurricane-prone areas and the effects of global warming point to the probability of future catastrophic disasters with large numbers of casualties.

Figure 193-1 Large-scale catastrophes, such as this earthquake in Pakistan (2005), have the potential to cause much injury and psychological stress.

Factors that indicate an increasing probability of mass casualty incidents include terrorist activity; increasing population density in floodplains, seismic zones, and areas susceptible to hurricanes; production and transportation of thousands of toxic and hazardous materials; risks associated with fixed-site nuclear and chemical facilities (illustrated by damage to the Fukushima nuclear power plants after the 2011 Japan earthquake and tsunami); the possibility of catastrophic fires and explosions; and global warming. As an example, the U.S. Geological Survey has identified volcanoes in the western United States and Alaska that are likely to erupt in the future, including Mt. Hood, Mt. Shasta, and the volcano underlying Mammoth Lakes in California. Because of the rising population density in these areas, hazards from volcanic activity are increasing. Ash from the 2010 Eyjafjallajökull eruption in Iceland grounded aircraft in Europe for weeks.

Given this probability and the increasing role of emergency medicine in disaster preparation, mitigation, response, and recovery, this chapter discusses disaster planning and operations with emphasis on the role of the emergency physician. The emergency physician has extensive responsibilities for community disaster preparedness and disaster medical services, including response to terrorism. In position and policy documents, the American College of Emergency Physicians outlines the scope of emergency medicine’s involvement in preparedness and response to disasters and terrorism, stating that “emergency physicians should assume a primary role in the medical aspects of disaster planning, management, and patient care” and that “emergency department personnel will become the first responders to a covert biological attack.”1,2

A committed emergency department alone is insufficient to provide hospitals with a successful disaster preparedness program. Institutional commitment by every hospital department and the administration is necessary to coordinate effectively with system-wide resources for disaster management. This is especially critical for creation of hospital surge capacity.3–5 A partial listing of general disaster medicine resources can be found in Table 193-1.

Table 193-1

List of Disaster Medicine Resources

ORGANIZATION	WEBSITE
The Joint Commission	www.jointcommission.org/
American College of Emergency Physicians	www.acep.org
Centers for Disease Control and Prevention, Emergency Preparedness and Response	www.bt.cdc.gov/training/
FEMA National Preparedness Directorate, National Training and Education	http://training.fema.gov/
National Response Framework	www.fema.gov/emergency/nrf/
Agency for Healthcare Research and Quality	http://archive.ahrq.gov/prep/
Koenig and Schultz’s Disaster Medicine: Comprehensive Principles and Practices	Cambridge University Press www.cambridge.org

The concept of surge capacity has emerged as a way to manage an event that produces a sudden influx of casualties with medical and health needs that exceed current hospital resources.⁶ This can be due to either the volume or types of victims. The three basic components of the surge capacity system are commonly referred to as the three s‘s of staff (hospital personnel), stuff (supplies and pharmaceuticals), and structure (physical location and management infrastructure). A complete discussion of surge capacity is beyond the scope of this chapter but has been published elsewhere.⁷

Within the context of surge capacity, new protocols are being developed that address allocation of resources when the medical and health needs of a population exceed current inventory. The issues involve creation of an equitable system for scarce resource allocation strategies, including assignment to an intensive care unit. Although no universally accepted approach currently exits, a system to optimize patient outcomes in a resource-constrained environment is clearly needed.

Nature of Disasters

Definitions

One of the challenges facing those responsible for disaster preparation is that no standard definition of disaster exists. Some events that have been routinely classified as disasters clearly are not. For example, many would consider a plane crash a disaster, yet it may not even approach overwhelming of the resources of the local responders. Because disaster medicine is multidisciplinary and depends on the integration of multiple levels of responders, the use of a common, precise terminology is essential.

In general terms, an event can be considered a disaster when it overwhelms response capabilities. These response capabilities can change in diverse environments or even in the same location at different times of the day or days of the week. For example, a multiple-vehicle collision with 6 critically injured patients and 12 patients with minor injuries could overwhelm both the emergency medical services system and the hospital in a small rural community. In an urban area with multiple hospitals that participate in a trauma system, however, this same event could be managed with routine resources. Thus it is the functional impact on the specific entity that is the key concept in determining whether a disaster exists.

Classic Terminology

The words internal and external refer to a hospital setting to help distinguish whether an event has occurred within the hospital grounds (internal) or in the community (external). This concept distinguishes between preparing for casualties to arrive at the hospital and dealing with casualties or resource problems within the hospital. This geographic distinction between internal and external may be useful, but it has severe limitations. Many events can be both internal and external to the facility at the same time (e.g., major earthquake or hurricane). Furthermore, simply identifying the location of the event does not answer the critical question: How are response capabilities affected?

An etiologic descriptor for an event is another customary classification. It does not matter whether a disruption in the ability of the hospital to respond is caused by nature or by humankind. The key consideration is what actions are required to mitigate and then to rectify the situation. Although the terms natural and man-made are prevalent disaster descriptors, they generally do not add anything of value, and therefore some experts have advocated removing them from the disaster lexicon, particularly because the etiology of the event may be unclear in its initial aftermath.

Some definitions have been based on the number of casualties. As previously described, the absolute number of patients is much less important than whether their medical and health needs exceed the resources to care for them at a given point in time. Another historical scheme divides disasters into three levels. Level I denotes a situation in which local resources are adequate to care for casualties. For example, the 2002 collision between a freight train and commuter train in Orange County, California, was managed effectively by local responders. Level II means that regional mutual aid is required to respond to the event. This was the case at the Hyatt Regency Hotel in Kansas City in 1981 when two skywalks collapsed, killing 114 people and injuring hundreds. Level III incidents require state and federal aid. The attack on the World Trade Center in 2001 (Fig. 193-2) and hurricane Katrina in 2005 were such events, causing such massive destruction that federal disaster medical assistance teams were deployed to New York and Louisiana, respectively, to provide medical personnel and supplies.

Figure 193-2 The World Trade Center attack of 2001 overwhelmed local resources and necessitated state and federal help.

One model eliminates the word disaster and replaces it with the acronym for potential injury-creating event, PICE.8–10 The PICE nomenclature is an attempt to resolve the issue regarding diverse meanings for disaster. This model is referenced in the Joint Commission standards and in publications from several countries. The PICE system is discussed here to help clarify important concepts in describing an event.

Potential Injury-Creating Event Nomenclature

The acronym PICE and its modifiers concisely describe the critical features of most types or degrees of disaster.8–10 The same occurrence can have different effects at different points in time; thus, as an event evolves over time, its description may change.

Modifiers are chosen from a standardized group of prefixes along with a stage to indicate the need for outside medical assistance (Table 193-2). The first prefix (column A) describes the potential for additional casualties. The second prefix (column B) describes whether local resources are overwhelmed and, if so, whether they must simply be augmented (disruptive) or whether they must first be totally reconstituted (paralytic). The third prefix (column C) shows the extent of geographic involvement.^8–10 Column C refers strictly to the affected region and not to the location that sends assistance. Rather, the “stage” rating scale defines the likelihood that outside medical assistance will be needed either to augment or to completely reconstitute resources.⁸ Stage 0 means that there is little or no chance. Stage I means that there is a small chance and requires placing outside medical help on alert. Stage II means that there is a moderate chance and outside help should be placed on standby. Stage III means local resources are clearly overwhelmed and require the dispatch of outside resources and commitment of personnel. For example, a multivehicle collision with a dozen injuries and several deaths in a large city would be a stage 0, whereas in a small rural town it might be a stage III (Table 193-3).

Table 193-2

PICE Nomenclature

PICE, potential injury-creating event.

Table 193-3

PICE Nomenclature Examples

World Trade Center attack, September 11, 2001	Dynamic, paralytic, local, PICE stage III
Los Angeles civil disturbance	Dynamic, paralytic, regional, PICE stage I
Northridge earthquake	Dynamic, disruptive, regional, PICE stage II
Oklahoma City bombing	Dynamic, disruptive, local, PICE stage I

PICE, potential injury-creating event.

A PICE can be either static or dynamic. Dynamic implies an evolving situation in which it is too soon after the incident to determine the numbers and types of casualties and the impact on the hospital. Alternatively, a static situation results if 10 people are injured in an incident and little potential for further harm exists.8–10

In some situations, enhancement of routine operations is not sufficient or possible. A PICE can completely overwhelm the capability to mount a normal response so that a substitute plan for recovery must be used. Situations that require significant reconstitution of critical resources are termed paralytic.8–10 Within the hospital, there are six critical elements necessary to provide a response (Box 193-1).¹¹ If one or more of these resources are compromised, they must be reconstituted or a substitute must be implemented. Such paralytic events can be either destructive or nondestructive (Box 193-2).⁸

BOX 193-1 Six Critical Substrates for Hospital Operations

Physical plant

Personnel

Supplies and equipment

Communication

Transportation

Supervisory managerial support

BOX 193-2 Examples of Paralytic PICE

Hazard Vulnerability Analysis

An important consideration in disaster planning is an awareness of the types of events for which the hospital or community is vulnerable. The classic example is the monumental risk from earthquakes in the central United States resulting from the combination of the New Madrid fault and the limited seismic safety requirements for buildings in that area. The planner must learn what types of support are available from outside agencies (e.g., hazardous materials decontamination from fire departments and information from poison control centers). Although awareness of such resources is critical, contingency plans must be available when such assistance is not accessible.

After performing a hazard vulnerability analysis (www.emsa.ca.gov/disaster/files/kaiser_model.xls), emergency planners should consider the most probable events and prepare for them. There should also be planning for events that are rare but catastrophic.¹² The major peacetime threat to life and limb in the United States is probably a large earthquake in a densely populated area or a terrorist attack. The disaster planner should proactively identify all such hazards and prepare contingency plans for each.

Triage

The term triage derives from the French verb trier, meaning “to sort.” The concept of triage was used as far back as Napoleon’s time to assign priorities to treatment of the injured when resources were limited. Priority is given to the most salvageable patients with the most urgent conditions. The emergency department uses triage in the hospital setting on a daily basis, but the focus of such triage is changed under disaster conditions.13,14 Standard emergency department triage is intended to identify the most seriously ill patients first and to ensure that they receive rapid care. The goal of disaster triage is slightly different, that is, “to do the most good for the most people.” In other words, there is a shift from focus on individual patients to focus on the entire affected population.¹⁵ It can be difficult for physicians to realize that to achieve the goal of maximizing benefit to an entire population of patients, they may need to let some patients die with only comfort care. Under true disaster conditions, cardiopulmonary resuscitation should not be performed.¹⁶

Routine Multiple-Casualty Triage

To assist in understanding of triage techniques, it is useful to consider a routine out-of-hospital event with multiple casualties (e.g., a multivehicle collision). In such situations, rescue personnel often use a Simple Triage and Rapid Treatment (START) technique that depends on a quick assessment of respiration, perfusion, and mental status.¹⁷ These three assessments can be remembered by the mnemonic RPM (respirations, perfusion, and mental status). Initially, all victims who are able to walk are asked to move away from the immediate incident area. These patients are classified as green, or “walking wounded,” and are reassessed after the more immediately critical patients are triaged.

The Pediatric Triage Tape (PTT) and JumpSTART have been proposed for the triage of children. JumpSTART is a modification of the START triage protocol that includes an additional step of five rescue ventilations for children presenting apneic and modification of criteria for hypoventilation and tachypnea as well as for a decrease in mental status. The PTT uses criteria that change in proportion to increasing victim size. The parameters for a child 50 to 80 cm in length are illustrated in Figure 193-3. In a comparison of sensitivity and specificity between the PTT and JumpSTART in pediatric trauma patients, the PTT demonstrated superior outcomes.¹⁸ Both START and the PTT appear to be useful tools, but only START has been evaluated in an actual disaster situation.^19–21

Figure 193-3 Pediatric Triage Tape algorithm for a child 50 to 80 cm in length.

As illustrated in Figure 193-4, a rescuer can assess each patient in seconds, quickly checking respiratory rate, pulse, and ability to follow commands (mental status), and divide the patients into the remaining three categories: red (immediate), yellow (delayed), and black (deceased). The only patient care interventions provided during this process are the opening of an obstructed airway and direct pressure on obvious external hemorrhage. At this point, patients are generally transported to a hospital for definitive care. Most often, patients arrive with a color-coded triage tag and are reassessed and retriaged by the hospital staff (Fig. 193-5). An outcomes-based evaluation of the performance of START triage in an actual disaster (2002 Placentia Linda train crash) demonstrated acceptable levels of undertriage (100% sensitivity of the red category and 90% specificity of the green category).²¹ However, significant amounts of overtriage occurred. Use of START also appropriately prioritized the transport of victims, with patients triaged as red arriving at hospitals earlier than patients triaged as yellow or green.

Figure 193-4 Simple Triage and Rapid Treatment (START). Victims who can walk are identified first and triaged into the “minor” category. Those remaining are triaged by the algorithm. (Modified from Triage—START and SAVE. In: Medical Disaster Response Training Course Syllabus. Dana Point, Calif, Medical Disaster Response, 1993.)

Figure 193-5 Triage tag to be used in multicasualty or disaster patient assessments.

Recently, a multidisciplinary group was formed to propose a potential national triage system for the United States. The result, derived by consensus of opinions, was referred to as SALT (sort, assess, lifesaving interventions, and treatment or transport).²² It differs from START mainly in the assessment of respirations (relies on a qualitative evaluation of respiratory distress rather than a number), the requirement for performance of certain emergent interventions (chest decompression), and an unstructured estimate of survivability. The algorithm is more complicated than START, and no current data exist evaluating its sensitivity, specificity, or other performance characteristics in a disaster. As such, it is not currently possible to make recommendations for its use.

Catastrophic Casualty Management

Triage during a widespread, catastrophic disaster differs from triage performed in routine out-of-hospital and hospital settings. The number of victims is vastly increased, and medical resources are severely limited or even initially absent. Patients may remain on scene for an extended period and should be frequently reassessed. If hospitals remain accessible, patients tend to seek care at the closest one, a phenomenon known as convergence. Hospitals close to the disaster scene are overwhelmed, whereas hospitals located only a few miles away may receive few if any patients. More likely, the hospitals will be rendered nonfunctional. The triage process will then be decentralized, occurring at multiple sites, or compartments, simultaneously throughout the disaster zone. Rather than a single scene or localized disaster, this can be thought of as a compartmentalized disaster.

To address this situation, researchers developed the Secondary Assessment of Victim Endpoint (SAVE) system of triage.²³ The SAVE triage system is designed to identify patients who are most likely to benefit from care available under austere field conditions in a resource-poor environment. When it is combined with the START protocol, SAVE triage is useful for any scenario in which multiple patients experience a prolonged delay in accessing definitive care.

The SAVE methodology is designed for use by health care providers under two conditions: (1) for those working within the disaster zone that begin caring for patients immediately but may not be able to transport patients to a definitive care facility for days and (2) for those caring for patients within hospitals where demand for resources exceeds supply. This second situation can occur as hospitals attempt to increase surge capacity. It is immediate and dynamic rather than delayed and static. Although there are many elements in common with other triage systems, rapid transport to a functional medical center within the “golden hour” may not be possible.

The SAVE triage methodology divides patients into three categories: (1) those who will die regardless of how much care they receive, (2) those who will survive whether or not they receive care, and (3) those who will benefit significantly from austere field interventions. Only those patients expected to improve receive care beyond basic and comfort measures. With use of SAVE, patients are separated into these three categories so resources can be focused appropriately. The decision to place patients in a particular group is based on field outcome expectations derived from existing survival and morbidity statistics.²³ An example is a situation in which three victims require chest tubes (two victims require one tube each and one victim requires two tubes), but only two chest tubes are available. The SAVE principles guide providers to place their last two chest tubes into the two victims who need it rather than into the single victim requiring two tubes.

During the triage process, individuals who would most benefit from early transport should be marked as “first out,” in case an evacuation opportunity occurs. These would be victims with medical problems readily treatable at a hospital or facility with equivalent capabilities but untreatable and fatal in the field. A patient requiring surgery for intra-abdominal hemorrhage is a common example.

Since nuclear, biologic, and chemical terrorism has become a threat, new triage systems are under development.13,24 These systems attempt to incorporate the added threats from exposure and contamination into the triage process. One such method for biologic casualties triages many individuals to home observation rather than hospitalization to optimize resource use and to minimize the spread of the infectious agent.²⁴ In addition, responders must be protected from secondary contamination or exposure; therefore, part of the triage algorithm should include a risk assessment and determination of whether and what type of personal protective equipment should be donned before patients are assessed. A quick determination is critical to prevent patient deaths from traumatic injuries while awaiting medical care from responders concerned about their own health and safety. This is particularly true in a “combined event” scenario, such as an event involving a radiologic dispersion device. Also associated with terrorism incidents are large numbers of psychogenic casualties,

Buy Membership for Emergency Medicine Category to continue reading. Learn more here