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Biological, chemical, and nuclear weapons have been evaluated and employed for military purposes during the twentieth century. There is now considerable concern that these so-called weapons of mass destruction are possessed by domestic and foreign political dissidents. The use of these unconventional weapons in acts of civilian terrorism must be considered when amending the disaster plans within our communities. Because of the important role that surgeons play in trauma centers and in disaster planning, it is important for surgeons to understand the potential agents and the specific features of disaster planning in this “new era.”

Anthrax is the best known of the biological weapons. The spore form of Bacillus anthracis can be aerosolized for inhalation as a terrorist agent. The spore germinates to the vegetative phase after inhalation and causes a fulminant systemic septic response that commonly leads to death within 48 hours of clinical symptoms. Clinical diagnosis by conventional cultures would likely not occur in a rapid enough fashion, and an index of clinical suspicion would be unlikely for this diagnosis given the very small numbers of afflicted patients with inhalational anthrax during the last century. Index cases of anthrax would likely only be diagnosed from autopsy or postmortem cultures. Recognition of any case must stimulate suspicion of malicious dissemination of spores, and should raise the concern that additional cases are to follow. Doxycycline or ciprofloxacin are considered postexposure and therapeutic treatment. Infected patients are not considered infectious to health care workers and standard infection control practices are considered sufficient in the management of these patients.

Plague bacillus (Yersinia pestis) is the cause of an occasional infection annually in the United States. It has been considered a viable biological weapon since aerosolized bacilli readily cause a fulminant pulmonary infection. Pulmonary infection is an infectious risk to others and makes this pathogen a troublesome terrorist prospect. Pulmonary infection leads to death in 48 hours. Cultures will establish the diagnosis, but usually without benefit to the patient if the diagnosis was not suspected and treatment already employed. Aminoglycosides and tetracyclines are approved for treatment and postexposure management. Full respiratory isolation of patients with pulmonary plague is necessary for 48 hours after the onset of antibiotic therapy.

Tularemia infection (Francisella tularensis) is also a proposed biological weapon. This infection is especially concerning because of engineered resistance that may exist in “weaponized” strains. Only small numbers of inhaled bacteria are required to cause either a fulminant infection with death or a protracted and clinically debilitating illness. It is an uncommon naturally occurring infection. Special culture requirements are necessary for isolation of the pathogen, and reference laboratory assistance for immunohistochemical or polymerase chain reaction assays may be useful. Aminoglycoside therapy is recommended but tetracycline and fluoroquinolones also have activity against the organism.

Smallpox is an airborne viral infection that is believed to be clinically eradicated since the 1970s. Vaccination of the population against smallpox stopped in the late 1970s, and concern has been raised about the security of remaining smallpox viral cultures. Inhalation of the virus results in a systemic viremia that is characterized by a characteristic rash. Guarnieri bodies may be seen on appropriately stained scrapings of the cutaneous lesion. The systemic disease has a 30% mortality rate. No antiviral therapy is currently available. Because the young population are unvaccinated, and the older population may have an attenuated vaccination status, concerns about smallpox as a terrorist tool has even generated discussion about reinstitution of public vaccinations. However, the vaccine has a definable morbidity rate. Because smallpox is transmissible from human to human, isolation of infected individuals is necessary until separation of the cutaneous lesions has occurred.

Botulinum toxin is a potent neurotoxin from Clostridium botulinum. The fine powder is readily aerosolized and inhaled. It could be used to contaminate food supplies. Poisoned individuals have a rapidly evolving paralysis. The diagnosis is a clinical one, although reference laboratories may be used for detection of the toxin from serum or gastric aspirates. Botulism antitoxin may be useful in treatment only if administered very early in the course of the disease. Otherwise, management is supportive until recovery occurs, which may be for several weeks. Obviously a large number of patients with botulism from inhalation will saturate the ventilator capacity of most communities. Standard infection control precautions to prevent nosocomial infection are appropriate, but isolation is not necessary.

The number of other potential infectious agents are many. Brucellosis, cholera, Q fever, and Glanders are bacterial infections that have been proposed as biological weapons. Equine encephalitis viruses and the hemorrhagic viruses are viral agents of concern. Ricin from the castor bean and mycotoxins are other biological toxins. With bioengineering technology, common bacterial species can be manipulated genetically for enhanced virulence or for antimicrobial resistance.

The use of sarin gas via a very crude delivery system in a train system in Japan in 1995 demonstrated that chemical terrorism can be an issue. Cyanide gas results in a rapid poisoning after inhalation that renders cells unable to utilize oxygen. A high index of suspicion with the rapid administration of sodium nitrite and sodium thiosulfate antidotes are necessary for treatment.

Nerve gases (eg, sarin) inhibit acetylcholinesterase and cause rapid paralysis. The administration of atropine and pralidoxime chloride is the specific treatment. Atropine is a competitive inhibitor of the excess acetylcholine that is present and pralidoxime regenerates the active enzyme that has been bound by the inhibitor. Timing is important in the delivery of the treatment, since “aging” of the bound acetylcholine may make the drug ineffective if administration is delayed several hours.

Phosgene is a pulmonary toxicant that provokes a severe inflammatory response within the lung tissue when inhaled. The resultant chemical pneumonitis renders the patient unable to oxygenate the blood. Management of the patient with phosgene exposure is with supportive care with a tracheostomy and ventilator support in severe cases until the inflammatory response recedes. The capacity of the health case system for ventilator support would be an issue with exposure of a large number of victims.

Sulfur mustard is a vapor that is a vesicant that topically injures skin and eyes. It may have effects similar to phosgene if inhaled in large enough quantities. It is an agent for incapacitation rather than killing people. Exposure of large numbers of victims would saturate the health care system. The management of soft tissue injuries are similar to partial thickness burns.

Radiation exposure may occur from either radioactive material that is dispersed in the environment, radioactivity that is added to a conventional explosive (eg, “dirty bomb”), or from an actual nuclear detonation. The physiologic consequences are directly related to the dose of radiation exposure. Doses of less than 1 Gy have little consequence, whereas doses of more than 8 Gy are usually fatal. Radioactivity that is dispersed from a device or is released from a dirty bomb would not likely result in sufficient radiation exposure to cause injury or death, but will certainly have profound psychosocial consequences. A nuclear detonation would have severe consequences from blast injury, thermal burns, and from high doses of radiation exposure depending on the explosive power of the device and the distance from the detonation epicenter. A 1-kiloton device would have a potential LD₅₀ radius of 5.5 km.

The management of patients after a dirty bomb or nuclear explosion will not be performed with knowledge as to the degree of radiation exposure. Treatment should be undertaken based on physical injuries that have been sustained and not the suspected degree of radiation exposure. Surgeons should understand that after effective decontamination, irradiated patients are not radioactive.

The severity of radiation exposure is best monitored by the evaluation of gastrointestinal symptoms, fever, and most importantly by hematologic changes. Neutrophil and platelet counts by 24 hours after exposure can be mapped against known responses to give an estimate of the severity of exposure. Immunosuppression is a major concern and nosocomial infection becomes a major issue in survival. The use of granulocyte-colony stimulating factor (GCSF), granulocyte-monocyte-colony stimulating factor (GMCSF), and even bone marrow transplantation have been proposed for victims of radiation accidents, but will likely have limited utility after a terrorist event.

Disaster planning in this era of unconventional acts of civilian terrorism requires cognizance of new realities. Dispersal of large amounts of biological contamination could occur in a subtle fashion with recognition not being appreciated until clinical infection surfaced in the health care system. Dispersal in a public place could result in ongoing exposure of people over several days. As in Japan, chemical terrorism could produce a large number of casualties in a very short period of time, with ventilator capacity and specific antidotes being in short supply. Contamination of conventional explosives with biologicals or radioactivity could result in significant exposure of the hospital personnel and environment. A nuclear explosion could produce a volume of casualties—many of which would have fatal radiation exposure—that would totally dwarf the entire health care infrastructure.

Identification of an event may not be readily appreciated with biological contamination. Index cases of anthrax, plague, or smallpox must be recognized so that the entire health care system can be alerted, or a high level of suspicion can be generated. Index cases allow data to be collected immediately so that potential sources of the contamination can be tracked and potential populations of exposed patients can be identified. Conventional explosives may have a dirty component and this may mean that responses to any explosion that appears to be a potential terrorist event should activate a generic response with personal protective equipment being worn by emergency and first response personnel, and with patients being decontaminated as a standard response.

In the wake of an identified event, the volume of injured and exposed patients will likely overwhelm the health infrastructure. Only patients with physical injuries should be evacuated to the hospital and others with minimal injury or “exposure” should be treated at alternative treatment centers where decontamination and assessment can be made. Law enforcement and the media will also be necessary to help divert the “worried well” to the alternative sites and away from hospitals.

A central command and control center should be planned and then activated with a recognized event. The central command with a director and small advisory group directs the flow of patients, apprises capacity issues, and coordinates evacuation. Contact with state and federal agencies should be initiated by the central command. Similarly, each hospital facility needs an analogous command and control structure to manage resources, personnel and patient flow, and to be in contact with the community-based control structure so that all efforts are coordinated in a common plan.

Prehospital care requires triage, field decontamination, and evacuation directives. The triage process includes identification of which patients are evacuated first, to which facility the casualties are evacuated, and the very difficult proposition of which patients should not be evacuated at all. In a true massively destructive event (eg, nuclear detonation) the magnitude of casualties will exceed the capacity of the system and will require decisions about only those patients with injuries who have a reasonable prospect for recovery.

Decontamination for presumed biological, chemical, or radioactive contamination is performed rapidly by removal of clothing and total body rinse. The disaster plan should entertain temporary, inflatable decontamination units for mass bathing, and must include disposable gowns for decontaminated individuals. With an inability to achieve field decontamination, that decontamination must still be achieved before patients gain access into hospital or alternative care facilities.

Alternative care facilities can be immediately created out of sports areas, gymnasiums, or other large auditoriums. Shower facilities within the alternative care facility might be used for decontamination by directing patient flow through the shower area before patients access the larger area for evaluation and care. Each community should designate several different potential facilities, with the number to be activated being dependent on the apparent magnitude of the event.

Hospital-based care will require full mobilization of all personnel as detailed in the disaster plan. Hospitalized patients will need to be discharged rapidly and all inventories of critical supplies, pharmaceuticals, and so forth will need to be accessed and mobilized. Patient flow rates into the emergency area and processes for triage using emergency and surgical leadership is essential. Triage at the hospital for treatment priorities will need to be vested in the most experienced clinicians available.

Finally, the resources available within a community in a major mass casualty situation will not be sufficient and will require immediate state and federal notification and assistance. The Federal Emergency Management Agency (FEMA) should be contacted immediately to permit activation of external workforce and resources. The National Pharmaceutical Stockpile is one program that can mobilize large shipments of antibiotics, antidotes, and other supplies to the location. Many states have, or should have, resource mobilization and sharing agreements to cover these events.

In conclusion, the details of the disaster plan in our communities and our hospitals need to be amended to cover the unconventional acts of civilian terrorism. It is likely that such an event will occur. Disaster planning is truly a local process, and it will only be as effective as the local effort.