Terrorism and Weapons of Mass Destruction

• The FBI defines terrorism as the unlawful use of force or violence against persons or property to intimidate or coerce a government or civilian population in furtherance of political or social objectives.
• The goal of the terrorist is to create fear. Even if a threat is not carried out but makes people scared enough to prepare, the terrorist has won.
• Fortunately, the attack most likely to occur, the use of conventional explosives, is the one with the lowest destructive power. Conversely, the weapon with the highest destructive power, nuclear attack, has the lowest likelihood of occurrence. In the middle are chemical and biological weapons, both of which have moderate destructive power and moderate likelihood of use.
• Unfortunately, the majority of hospitals are unprepared for large terrorist activities since there is little financial incentive to prepare for an event that may never occur.
  Additionally, in the civilian population, little is known about how to handle most of these events. The current medical literature is not sufficient and provides little or no practical guidance. Most information is gained from military sources and is of limited value in the civilian setting.
• Decontamination
• A lot of time, money and energy are spent on preparing a disaster management within the hospital to decontaminate victims of a chemical or biological attack. In reality, decontamination by hospital personnel is not useful and can be dangerous. Furthermore, training hospital personnel is expensive, risky, a potential legal liability. Hospitals must arrange for trained “hazardous materials” teams to respond as needed.
• Some decontamination is unnecessary. People can be either exposed or contaminated by a chemical or radioactive material. Exposed victims (i.e., inhalation) do not require decontamination procedures. Secondary exposure to the health care worker is minimal. Contaminated victims (liquid or powder on clothing or skin) require decontamination, which includes removing clothes and rinsing with copious amounts of water.
• Categories: the following list represents only a fraction of potential agents that could be used by terrorists. A detailed discussion of all agents is beyond the scope of this chapter although nerve agents and radiation will be reviewed.
• Chemicals
• Nerve agents: Tabun, Sarin, Soman, VX
• Irritant gases: chlorine, phosgene, and others
• Vesicant gases: mustard and lewisite
• Cyanide
• Riot control agents: mace and pepper spray
• Biological
• Bacteria: Anthrax, plague, Brucellosis, Q-fever, Tularemia, Salmonella
• Viruses: smallpox, Venezuelan equine encephalitis, viral hemorrhagic fevers
• Fungi: mycotoxins
• Bacterial toxins: Staphylococcus enterotoxin B, ricin, botulinum toxin
• Nuclear
• Incendiaries and explosives

Nerve Agents

• Nerve agents are organophosphate esters that can be inhaled, ingested, or absorbed through the skin. Toxicity is related to their ability to bind with the enzyme acetyl cholinesterase, which prevents the breakdown of acetylcholine at the neuromuscular junction. All nerve agents are liquids but can be aerosolized for inhalation.
• In general, victims exposed to a lethal amount will die on scene if untreated. Victims who arrive at a hospital without decontamination procedures do not have a lethal exposure. These victims have been exposed to the chemical and do not require a shower.
• Removal of clothing and the changing into a hospital gown is all that is required since the clothing may contain trapped vapor.
• Clinical presentation: can be divided into muscarinic, nicotinic and CNS effects:
• Muscarinic: the “sludge syndrome” consisting of salivation, lacrimation, urination, defecation, GI distress, and emesis. Other effects include bronchoconstriction, laryngospasm, chest tightness, bradycardia and heart block.
• Nicotinic: includes muscle fasciculation, twitching, jerking, weakness, flaccid paralysis, hypertension, tachycardia, mydriasis and diaphoresis.
• Central nervous system (CNS): includes seizures, altered mental status, agitation and coma.
• Death is usually due to respiratory failure from diaphragmatic paralysis and or increased bronchial secretions.

Treatmen
Atropine

• Antagonizes the muscarinic effects but has no effect on nicotinic symptoms.
• Administer at first sign of symptoms.
• Can be given IV, IM, or by endotracheal tube (IV preferred).
• Dose
• Adults: begin with 2 mg with repeat doses given as needed.
• Children: begin with 0.02 mg/kg IV (0.5 mg minimum and 2 mg maximum)
• The dose should be repeated as clinically indicated with the endpoint being the drying of secretions.

Pralidoxime (Protopam, 2-PAM)

• Most effective when given early. Start therapy as soon as you make the diagnosis.
• Removes nerve agent from acetyl cholinesterase.
• Acts at both muscarinic and nicotinic sites. It is synergistic with atropine, thus decreasing the atropine requirements.
• Dose
• Adults: 1-2 g slow IV (dilute with 100 ml of normal saline and infuse over 15-20 min). May require repeat doses or an infusion.
• Children: 20-40 mg/kg IV (IV preferred but may be given IM) to a maximum of 1 g.
• The dose is repeated in 1 h if muscle weakness persists. Additional doses or an infusion may be necessary.
• Endpoint of therapy is the absence of signs / symptoms (weakness) of poisoning after the 2-PAM is stopped.

Benzodiazepines

• Used to control associated seizures.
• Decreased neurologic morbidity in patients treated with benzodiazepines. Administer in all severe cases to prevent seizures.

Radiation Injuries

• Radiation is typically expressed in terms of rem when referring to biological exposure.
  The dose that is lethal for ~50% of subjects is 400 rem. Doses above 600 rem have nearly 100% mortality. Radiation doses received over a long period of time are less toxic than doses received over a short period of time.

Ionizing vs. Nonionizing

• Ionizing radiation includes gamma rays, X-rays, a particles, and ß particles.
• Nonionizing radiation includes UV-rays, visible light, infrared, radio waves, and microwaves. Nonionizing radiation usually only causes mild problems related to local heat production.

Types of Ionizing Radiation

• Alpha particles: relatively harmless if intact skin; penetration limited to the epidermis.
• Beta particles: can cause deeper skin damage but are completely blocked by clothing.
• Gamma rays: deep tissue penetration and are the primary cause of acute radiation syndrome.
• Note that otherwise harmless a and ß particles are dangerous if inhaled, ingested, or located in open wounds.

Irradiation vs. Contamination

• Irradiation: a radioactive substance has passed through a person, but that person is not made radioactive.
• Contamination: radioactive particles remain on the person or within any wounds that are present. This is generally seen with a/ß particles and can pose a risk to health care personnel.

Acute Radiation Syndrome (ARS)

• Results from internal or external exposure over a short period of time.
• Tissues with higher rate of cell turnover are more sensitive (gastrointestinal, hematologic).
• Severity of ARS can be estimated based upon clinical symptoms and certain blood markers.
• Note that the radiation dose is inversely related to time of symptom onset (rather than symptom severity).
• Nausea and vomiting (N/V) within 2 h of exposure indicates dose of >400 rem.
• N/V after 2 h suggests dose < 200 rem.
• Diarrhea indicates exposure >400 rem with bloody diarrhea being a bad prognostic sign.
• CNS symptoms and seizures indicate very high dose (>2000 rem) as this is the organ system that is least sensitive to radiation injury.
• Management
• Determine dose/type of radiation if possible.
• Determine if patient is contaminated as this will pose a risk for all health care personnel.
• Decontamination includes removal of clothing followed by rinsing with water.
• This should be started in the field but may need to take place in the hospital for severely injured patients. Hospital decontamination should follow the specifications of the existing disaster plan, disaster management. Ideally this involves use of a separate ED entrance and decontamination room with closed drainage and ventilation systems.
• Contaminated wounds may require surgical debridement or amputation.
• Reverse isolation for exposure >200 rem.
• Supportive care as indicated (there is little that one can do after decontamination).
• There are chelators/blocking agents which can be used for certain types of radiation: potassium iodide for radioactive iodine; EDTA for radioactive lead; DTPA for heavy metals.
• Prognosis: depends upon the dose and duration of exposure and can be estimated by absolute lymphocyte count at 48 h after exposure.
• >1200: good prognosis and nonlethal exposure.
• Between 300 and 1200: fair prognosis with possibility of lethal exposure.
• < 300: poor prognosis and likely lethal exposure.

Biological Terrorism

• There are a number of agents and toxins to consider (see Table 21.1). A detailed discussion is beyond the scope of this chapter.
• Use of universal precautions can prevent transmission of most agents to healthcare providers. For example, an N-95 filter mask (orange duck bill as used for tuberculosis) is effective for many organisms. Some infections (e.g., inhalation anthrax) are not transmitted person-to-person.
• The best defense is an alert health care system. Identifying suspicious outbreaks of illness or unusual presentations of disease points to the possibility of a biological terrorism event.

Table: Biological warfare agents

Agent / Disease	Transmit: Man-to-Man	Incubation Period	Illness Duration	Lethality	Clinical	Prophylaxis	Treatment
Anthrax (inhalational) Bacillus anthracis	No	1-6 days (up to 30- 60 days)	3-5 days	High	Initial: fever, malaise, fatigue, cough Later: respiratory distress, strider, cyanosis; shock and death 24-36 h after onset severe symptoms CXR*: widened mediastinum, pleural effusion	Ciprofloxacin or doxycycline x 60 days	Ciprofloxacin, doxycycline, or penicillin
Brucellosis Brucellae sp.	No	5-60 days	Wk to mo	<5% (un-treated)	Fever, headache, fatigue, myalgias, anorexia, cough, GI**/joint/skeletal symptoms (CXR usually normal)	Doxycycline + rifampin	Doxycycline + rifampin
Plague, pneumonic Yersinia pestis	High	1-6 days	1-6 days	~ 100% unless Rx w/in 24 h	Fulminant course: fever, chills, headache, hemoptysis, dyspnea, cyanosis, strider, DIC***, respiratory failure, shock	Ciprofloxacin or doxycycline	Streptomycin, gentamicin, or doxycycline
Q Fever Coxiella burnetii	Rare	2-14 days	Days to wk	Very low	Fever, cough, pleuritic chest pain, and myalgias Self-limited even without treatment	Tetracycline or doxycycline	Tetracycline or doxycycline
Tularemia Francisella tularensis	No	1-21 days (avg 3-5 d)	Days to wk	Rare if treated	Ulcer formation, lymphadenopathy, fever/ chills, pharyngitis, non-productive cough, pneumonia	Ciprofloxacin, doxycycline, or tetracycline	Streptomycin, ciprofloxacin or gentamicin
Smallpox Variola virus	High	7-19 days (avg 12 d)	2-4 wk	High	Prodrome: malaise, fever/chills, vomiting, backache Rash: macules -> papules -> pustules (2-3 days after prodrome), central spread	Vaccine w/in 7 days (best w/in 24 h)	None
Venezuelan equine encephalitis (VEE)	No	1-6 days	Days to wk	Low	Fever, chills, severe headache, photophobia, myalgias, GI symptoms	None	Supportive
Viral hemorrhagic fever	High	4-21 days	7-16 days	Moderate to high	Fever, coagulopathy, petechiae, hypotension, multi-organ involvement	None	Supportive (Ribavirin— compassionate use)
Botulism (Clostridium botulinum toxin)	No	Symptom onset: 18 h to days	Days to mo	High	Ptosis, weakness, dizziness, dry mouth, blurred vision, diplopia, dysphagia, dysphonia, urine retention, ileus, descending flaccid paralysis, respiratory failure; patient remains afebrile with normal mental status	None	Antitoxin (give early), supportive care
Ricin (toxin from castor beans)	No	4-8 h	36-72 h	High	Weakness, fever, cough, hypotension, cardiovascular collapse, airway necrosis/edema (ingestion: GI bleed)	None	Supportive, lavage if ingested
Staph enterotoxin B (SEB)	No	3-12 h (inhalation)	Days to wk	Low	Fever, chills, headache, myalgias, nonproductive cough, pulmonary edema, GI symptoms (if swallowed)	None	Supportive

Terms:
*CXR: Chest radiograph, **GI: gastrointestinal, ***Disseminated intravascular coagulation.