ANESTHESIA AND DISASTER MEDICINE [back]
By Ernesto A. Pretto, MD, MPH

Especially in light of current global tensions in the wake of recent events, it is highly appropriate that we stop for a moment to think about emergency preparedness. In a national emergency, we may be called on to perform a variety of functions. As health care providers, what do we need to know? Specifically, what is the big picture? How do we fit into it? What might we be called upon to do in a national emergency? Where will we most likely be doing it? What anesthesia techniques and equipment will we need?

The following article is the first of a three-part series developed to address these issues. The articles are excerpts from a book that I am writing on Evaluation of Medical Disaster Response, and will appear in Anesthesiology News in three installments:

1. Basic Concepts and Definitions
2. General Framework for EMS Systems Response to Disaster and the role of the Anesthesiologist
3. Commonly Employed Anesthesia Techniques and Equipment for Disaster Medicine

Until recently, in some corners of the world the negative impact of disasters was accepted as fate. In other words, the human and economic losses were considered irreducible. Disaster was viewed as divine punishment, or regarded as the invisible hand of God, as mirrored in the term 'acts of God.' This thinking reflected the previous focus on natural disasters. The 20th century, however, was witness to a marked escalation in the frequency and magnitude of man-made disasters, such as armed conflicts and civil war, conventional wars, the development and use of weapons of mass destruction, the advent of large-scale international humanitarian emergencies, and terrorism. Arguably, the wars, civil strife, armed conflicts, and terrorism of the 20th century alone have killed and maimed more people than all of the natural disasters before this time. What is most disconcerting about this fact is that the 21st century appears to be headed in the same direction. Hatred, violence, and lawlessness are escalating at rapid rates worldwide, and are already a public health problem of gigantic proportions. Increasingly, hatred and violence are aimed at ethnic groups in the form of genocide and ‘ethnic cleansing.’

Prior to September 11, 2001, there was no collective awareness of the potential human impact of either natural or man-made disasters on American soil. Therefore, the level of preparedness for mass disasters in the United States had declined due to complacency. (1) This thinking has changed radically, and we are now engaged in an unprecedented effort to enhance homeland defense and prepare for the next disaster, which we know will come sooner or later – but in what form? Inevitably, the next strike will involve a weapon or weapons of mass destruction. However, if we focus all of our efforts in preparing for one type of scenario (e.g., bioterrorism), we may be caught off guard by another type (nuclear or chemical). Therefore, the best strategy is to improve our general capacity to respond to all hazards, while placing special emphasis on preparing for worst-case scenarios such as nuclear, chemical, or biological attack.

Unfortunately, health and medical programs for planning and preparedness, and for mitigation and response, have not been universally accepted and institutionalized. Moreover, disaster medicine and emergency public health are relatively new fields comprising many disciplines that deal with the medical and health consequences of disaster. As a result, many concepts, terminology, procedures, and curricula for educational and training programs have not been validated or standardized, nor are practices firmly rooted in science. For example, there are few fellowships in disaster medicine, and I know of no curricula in medical schools dealing with the subject. Recently, the Association of Schools of Public Health developed the first disaster-preparedness curriculum for schools of public health. (2)

The intent of these articles is threefold: to raise awareness about disaster preparedness, to educate about the current state of the art in disaster medicine, and to describe the role of anesthesia providers in it. As in any other discipline, it is important to understand the language and concepts commonly employed by experts in the field, which is why I devote this entire section to the basics. It is important also to understand the disaster-response organizational structure at the local, regional, state, and federal levels, because, only after a careful analysis of the organizational framework for disaster response can we begin to understand how our special expertise might contribute most effectively to this important effort.

I. Basic Concepts and Definitions

Disaster medicine, in its broadest perspective, can be defined as the delivery of medical and surgical care under extreme and/or hazardous conditions to the injured or ill victims of disaster. A hazard is a forceful natural or man-made event with the potential to adversely affect human life and property, or the environment. Natural hazards are a normal consequence of the internal and external forces that are constantly transforming the earth (e.g., earthquakes, hurricanes, tornadoes, volcanoes, etc.). Man-made hazards arise from deliberate human actions (e.g., war, terrorism, humanitarian emergencies, etc.) that are usually predictable and preventable. They may also arise from the unforeseen or unexpected consequences of human development and technology (e.g., nuclear weapons, industrial accidents, etc.). Natural hazards are an inevitable and necessary feature of life on earth, and are largely unpreventable. In other words, we must learn to accept and cope with these hazards. There are varying degrees of unpredictability – depending on hazard type – as to when, where, and how they will occur. The lethality of natural disasters is associated with their force, magnitude, and intensity and is greater as population density on earth increases. Consequently, natural hazards can have a negative outcome in terms of human and economic cost, the extent and severity of which determine whether it becomes a disaster or not.

In general, a disaster results when the extent of damage produced by the force of a natural or man-made hazard exceeds human capacity to cope with its consequences – when it destroys or places additional burdens on fundamental societal functions such as law and order, communication, transportation, water and food supply, sanitation, health services, etc. As a result, order is replaced by chaos. Chaos may be compounded by a disproportionate, inadequate, or disorganized response – the so-called ‘second disaster.’

Aside from the general definition of disaster given above, others have contributed numerous definitions from their individual perspectives. For example, Frederick C. Cuny, one of the leading experts in the field of hazard assessment and response, succinctly defined a disaster as “a situation resulting from an environmental phenomenon or armed conflict that produces stress, personal injury, physical damage, and economic disruption of great magnitude." (3) Perez and Thompson defined disaster as "the occurrence of widespread, severe damage, injury, or loss of life or property, with which the community cannot cope, and during which the affected society undergoes severe disruption." (4) The definition of a disaster adopted by the World Health Organization (WHO) and the United Nations is “the result of a vast ecological breakdown in the relations between man and his environment, a serious and sudden (or slow, as in drought) disruption on such a scale that the stricken community needs extraordinary efforts to cope with it, often with outside help or international aid.” (5)

Disasters can be viewed solely on the basis of the health impact. In this context, a health disaster occurs when it causes widespread injury or loss of life or when the social and medical infrastructure of a community is disrupted or so damaged by the event that it significantly reduces or impairs access by the community to the health system. During the war in Bosnia-Herzegovina (1992-1995), for example, a primary target of the aggressors was the health system. This resulted in minimal to no capacity to treat the ill and injured. (6)

Disaster outcome in terms of human and economic cost is highly dependent on the socioeconomic level of the affected community and its prior investment in quality infrastructure (i.e. buildings, highways, sewage systems, communication systems, etc), and disaster-preparedness programs aimed at improving prediction, early warning, prevention, containment, or mitigation. Prevention and mitigation together constitute disaster preparedness, and are usually based on lessons learned and comprehensive evaluations of real events.

Disaster mitigation is any medical or non-medical intervention aimed at reducing injury or damage once the event has occurred. For example, earthquake-prone regions with anti-seismic building design and construction (i.e., prevention) and well-developed and widespread EMS/trauma systems (i.e., mitigation) tend to have lower mortality and morbidity than poorly developed areas. Contrast the 1994 earthquake in Northridge, California, in which 58 people died, with an earthquake of similar magnitude in Kobe, Japan that killed 6,000 people in 1995.

Predetermined or pre-event factors can influence disaster outcome. For example, a natural hazard may exert its force with regular frequency but moderate intensity and low magnitude. Intensity refers to the energy or physical force and magnitude to the geographic area at risk. In this situation, a given society exposed to the same threat time and time again will learn to mitigate the effects through experience, by employing adaptive or coping strategies. In this instance, coping mechanisms are tested with regular frequency and are gradually improved, thereby increasing the resilience or resistance of the population to the adverse effects of a particular hazard, and ultimately improving the outcome of the disaster. However, hazards with very low frequency (e.g., once in 500 years) may not trigger adaptive/coping strategies because there is no collective memory from which to identify risks or to adapt. Also, high-intensity and high-magnitude hazards may cause populations to relocate with little to no adaptation. Later, new populations move in and settle in the area, with no knowledge of endemic hazards. Over time, population density and human infrastructure increase, and when disaster strikes again the cycle repeats itself. Therefore, in general, disaster outcome may be considered a function of hazard frequency, magnitude, intensity, and population density. However, outcome can be magnified by inherent weaknesses or vulnerabilities in the system.

Vulnerable is defined as ‘capable of being wounded, liable to injury, or subject to be affected injuriously.’ Vulnerability is the quality of being vulnerable. Within the context of disasters, the vulnerability of a population or society to a hazard is determined by the factors that predispose said society to injury or reduced health. Vulnerability can be classified into two general categories: natural or biological, and man-made or acquired. Biological vulnerability is determined by nature, and constitutes inherent human susceptibility to disease or physical agents, such as radiation or chemicals. Today, more than at any other time in history, an understanding of these biological susceptibilities is important for purposes of planning for defense against biological weapons of mass destruction. An example of a biological disaster based on immune susceptibility is provided by the colonization of the New World by the Spanish Conquistadors. This event was associated with the unintentional transmission of biological agents (disease) to a large, susceptible population of indigenous persons, which resulted in their near annihilation – a human disaster of massive proportions due to an inadvertent biological ‘attack’ on a vulnerable population. (7) The Spanish did not know anything about immunity, and thus did not deliberately exploit those vulnerabilities. But imagine what might happen in modern times, in an intentional act of biological terrorism.

Man-made or acquired vulnerability is determined by man’s ignorance, apathy, necessities, inaction, un-preparedness, poor level of sanitation, or low socioeconomic status, and contributes to the destructive potential of any superimposed hazard. For example, people living in a known earthquake region in low-quality, poorly constructed buildings that lack anti-seismic design and construction may suffer injury or death when an earthquake of even the lowest intensity strikes. This was the case after the 1988 earthquake in Armenia, where 25,000 people lost their lives, mainly because of shoddy construction. (8) In this case, poor quality building materials, along with inadequate construction techniques and practices, aggravated by widespread corruption, facilitated building collapse. Thus, man-made vulnerability is very often tightly connected to development, sometimes wrongly, as above, but also, sometimes correctly. For example, increasing a population’s economic vitality by deforestation may lead to some sort of development, but it also increases vulnerability to flooding and landslides in areas exposed to such threats. Building a hydroelectric dam, however, is clearly part of the process to provide clean, reproducible power; but the price is a hazard in the form of a potential dam-burst or a negative ecological impact upstream from the dam. New computerized telephone systems have made communications twice as vulnerable as before, when phones also worked even when the electrical power was down.

The same rationale concerning vulnerability may apply to other natural or man-made hazards, such as volcanic eruptions, wars, or technology (e.g., Three Mile Island). As mentioned above, man-made disasters such as wars can be prevented, but greater effort must be directed by the international community at early identification of ‘hot’ areas, solving the root causes of conflict, negotiating settlements, or stopping hostilities, in order to reduce or eliminate negative human impact.

In summary, disaster medicine is a relatively new medical science dealing with the health and medical aspects of disaster response. The most cost-effective method to reduce human injury and death in disaster is through prevention and mitigation. These are tied to socioeconomic level and development. The severity of disaster outcome is multi-factorial, directly proportional to hazard magnitude and intensity, population density, and the sum of vulnerabilities, and inversely proportional to the sum of preparedness and socioeconomic level of a region, and can be summarized in mathematical format, as follows:


When disaster strikes, the primary aim of disaster response is to restore order, support damaged or non-functioning societal functions, and shortly afterwards, reconstruct and rehabilitate the affected society to, at minimum, its pre-disaster situation. At that point, the primary aim of health and medical disaster response is to reduce morbidity and mortality.

In Part 2, we will discuss in detail how medical disaster response is designed and implemented, and the relevant first-aid and medical emergency support functions required for adequate emergency medical response involving large numbers of casualties.

Finally, in many ways our own nature and actions, and our reliance on technology, have predisposed us to disasters. Rather than ‘acts of God,’ increasingly, it is ‘acts of Man’ that have exacted the greatest human toll. In order to adequately prepare for disaster, it is important to understand the nature of hazards, to identify risks and vulnerabilities, to and adopt effective coping strategies based on experience and the systematic evaluation of the health and medical consequences of past disasters.

1. Pretto E, Safar P: National medical response to mass disasters in the United States. Are we prepared? JAMA 1991;266:1259-62.
   
2. Disaster Preparedness in Schools of Public Health: A Curriculum for the New Century. (Landesman, L, Editor). Association of Schools of Public Health (ASPH) and Centers for Disease Control and Prevention (CDC) April, 2000.
   
3. Cuny FC: Introduction to disaster management: Lesson 2 – Concepts and terms in disaster management. Prehospital Disaster Med 1993;8:89-94.
   
4. Perez E, Thompson P: Natural disasters: Causes and Effects, Lesson 1– Introduction to natural Disasters. Prehospital Disaster Med 1994;9:101-9.
   
5. Gunn SWA: Multilingual Dictionary of Disaster Medicine and International Relief. Kluwer Academic Publishers. Boston/London. 1990, p 23.
   
6. Pretto E, Begovic M, Begovic M. Emergency medical services during the siege of Sarajevo, Bosnia and Herzegovina: a preliminary report. Prehospital Disaster Med 1994;9(2 Suppl 1):S39-45.
   
7. Diamond Jared. Guns, Germs, and Steel. The Fate of Human Societies. (Guns, Germs, and Steel Main Page)
   
8. Pretto E, Ricci E, Safar P, et al: Disaster Reanimatology Potentials: A Structured Interview Study in Armenia III: Results, Conclusions, and Recommendations. Prehospital Disaster Med 1992;7(4):327-38.
   

   Suggested Additional Reading:
   
   Baskett P, Weller R. Medicine for Disasters. Butterworth & Co. (Publishers) 1988.
   
   Ricci E, Pretto, E. Assessment of prehospital and hospital response in disaster. Crit Care Clin 1991;7(2):471-83.

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