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Hazards and Threats

The concepts of a hazard and a threat are often confused. CBW agents are by definition hazardous and are strictly


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TABLE 64-2 -- Iranian experience with chemical warfare agents
During the Iran-Iraq War, modern medicine was applied to the treatment of injuries caused by sulfur mustard, tabun, Lewisite, and the biological agent mycotoxin.[33] [53] Although data are limited, there are a number of lessons that we should note. The most unexpected was the surprisingly low mortality: les than 1% of the estimated 27,000 Iranian chemical casualties.[34]
Troops with organophosphate exposure fell into four categories. Those with the greatest exposure died in the field. The number appears to have been very small even though most of the Iraqi attacks were made against the unprotected Iranian troops. Those most severely injured who reached medical aid were unconscious and unresponsive, and they were often in respiratory arrest. The seriously intoxicated had symptoms of dizziness, disorientation, anxiety, salivation, and respiratory difficulty. Those with relatively mild symptoms were often physically difficult to manage because of their disorientation. By far the largest number of casualties required no treatment other than decontamination.
Treatment of mustard exposure during the Iran-Iraq War reflects the experience gained in the management of burn wounds during the 80 years since World War I. Treatment begins with early and thorough decontamination. Early in the course of injury, blistering may not be present, but removal of contaminated clothing is important to limit the casualty's contact time with the agent. Shaving of the affected areas followed by washing mechanically removes and dilutes the agent. Aspiration of blisters, removal of necrotic tissue, and treatment of the skin lesions with silver sulfadiazine cream forms the basis for treatment of skin injury. Respiratory exposure to mustard creates its own set of problems. Depending on the degree of injury, the treatment must be adjusted to the degree of injury. Humidified air or oxygen helps to prevent airway obstruction. Bronchodilators, mucolytics, and expectorants are useful. In cases of serious injury, mechanical ventilation with positive end-expiratory pressure and acid-base balance control are used to support the casualty until the injuries resolve. Injury to the eyes is treated with irrigation and sodium sulymid. Pain is treated with systemic medications. Because of weight loss, often in excess of 10 kg, nutritional support is instituted to help reduce the significant mortality associated with negative nitrogen balance. After the patient reaches a setting for definitive care, therapy is divided into two parts: a general supportive treatment for sepsis and dehydration and treatment to eliminate toxins from the body.[53]
Significant observations from the Iran-Iraq War include the following:
• Decontamination, using soap and water and shaving body hair, was done early. This protected medical personnel and simplified further treatment.
• Comatose casualties of nerve agents who did not have cardiovascular problems were treated with large doses of atropine, 50 to 200 mg administered intravenously. Most casualties received 2 mg every 8 hours. Comatose casualties with significant cardiovascular deterioration (e.g., bradycardia after 2 mg of intravenous atropine) most often did not survive.
• Mustard, although it dates from World War I, continues to be an important chemical agent. It is a vesicant but also has effects on multiple organ systems.
Adapted from Baker DJ, Rustick JM: Anesthesia for casualties of chemical warfare agents. In Zaitchuk R, Grande C (eds): US Army Textbook of Military Medicine, part IV, vol 1. Washington, DC, US Department of the Army, 1995.

controlled by the provisions of the HAZMAT system. The term threat typically is used in the military context if a hazard has been weaponized and the assailant has the capability and the intention to use the weapon. The relationship may be expressed by a simple equation:

Threat = Hazard + Capability + Intention

The reality is that many of the CBW hazards causing public concern are very difficult to weaponize and deliver. Understanding this is important in formulating a balanced medical response because it reduces the likelihood of encountering casualties from CBW attack to a restricted number of agents, the properties and pathophysiology of which can be considered before casualties occur.

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