The term disaster is subject to a variety of interpretations and misperceptions that typically relate to one’s background and experience, but there are specific characteristics on which most would agree. An essential feature of a disaster involves a major disruption of the infrastructure of a community or geographic region and its inhabitants. Another is that the magnitude of destruction exceeds that of routine emergency situations to such an extent that the response to it must be entirely different in order to restore some semblance of order and normalcy. Approaching a disaster with the mindset of simply doing more of the same, using the same methods as routine emergencies, is generally doomed to failure and tends to extend rather than curtail the adverse consequences.1
True disasters are rare. Very few events in a century result in more than 1,000 casualties, and only about 10–15 events each year throughout the world result in more than 40 casualties.2 Because they are rare, as well as unpredictable, random, sudden, and unexpected, their successful management requires established and well-rehearsed plans that anticipate necessary consequences, procedures, and needs.2–4
The feature that best distinguishes the medical response to a disaster from the routine medical care of patients is that resources are overwhelmed by the casualty load. The receiving hospital is therefore unable to provide each casualty with the optimal level of care that is standard in routine medical management.5,6 External assistance is necessary to manage the event. This has significant impact on the approach to medical care and the associated ethical considerations, as, by definition, the limited resources must be rationed according to who most merits care so as to avoid squandering these resources and leaving many other casualties without care that may be more effectively applied in terms of overall casualty salvage. This means that some casualties who would ordinarily be treated may have to be denied full care for the sake of saving many more. These altered standards of care that must prevail in true disasters tend to be unfamiliar and morally repugnant to health care providers, and they are not taught in medical or nursing schools or residency training. This emphasizes the necessity of education and training in these principles if a medical response is to succeed.7 This response cannot just be more of the same, but an entirely different approach to care. The longer it takes to learn this as a medical response unfolds, the more property and lives will be lost unnecessarily.1
A multiple casualty event is one in which hospital resources are strained, but not overwhelmed, by the patient load, as we experience on busy nights in urban trauma centers and emergency rooms. All patients are ultimately fully treated according to our standard principle of the greatest good for each individual, although the costs include extra personnel, financial losses, delays in care, and difficulty in finding beds, operating rooms ...