Chemical, Biological, and Radiological Threats in the Tactical Environment: Overview of Identification and Treatment

Kelly R. Klein

Richard V. King

Phillip Carmona

Greene Shepherd

OBJECTIVES

After reading this section, the reader will be able to:

1. Hazardous material exposure risks for tactical operators.

2. The history of the use of hazardous materials as weapons.

3. Recognition of chemical, biological, or radiological contamination.

4. Field treatments and operational decision making for team members who have been contaminated.

HISTORICAL PERSPECTIVE

Many of the weapons that today would be classified as chemical, biological, or radiological agents have been used for more than 3,000 years. As early as 1000 B.C. the Chinese used arsenical smokes in warfare and throughout history. In 1346, the Tartars catapulted plagueinfected bodies and heads over castle walls during the siege at Kaffa. The British Army is reported to have distributed blankets used by smallpox patients to Native Americans in the late 18th century. The modern use of chemical weapons began during World War I when the Germans soldiers used chlorine gas against the French during the second battle of Ypres, which prompted retaliation and escalation by all sides, including the French, British, and Americans. There were approximately 1,300,000 casualties, including 90,000 deaths on both sides, primarily from blister agents and choking agents. This new form of warfare brought about changes in decontamination procedures and improved protective equipment, which are discussed in Chapters 40 and 41 (1, 2 and 3).

INTRODUCTION

Hazardous materials represent a complex and significant danger during tactical operations. The objectives of a tactical operation can be disrupted by even a single team member’s becoming contaminated with a hazardous material. Tactical medical providers are challenged with not only providing care but also making assessments about mission viability.

A hazardous material is defined as any substance that poses a substantial risk to the health or safety of individuals or the environment when improperly handled, stored, transported, or disposed (1). The specific risks are dependent on the quantity and concentration of the substance exposure and the physical, chemical, or infectious characteristics of the material. The exposure may be due to an unintentionally contaminated environment or be the result of an act of aggression. Environmental contamination may be due to waste products such as from methamphetamine manufacture or due to unintentional releases caused by accidents or collateral damage. Hazardous substances also have the potential to be used as unconventional weapons. This, coupled with current concerns about terrorism, indicates that tactical medics must be prepared for more than the typical environmental contamination; they must be trained in the signs, symptoms, and treatments of chemical, radiological, and biological weapons.

Since conventional weapons, that is, lead projectiles and explosives, are a tactical team’s most common threat, chemical, biological, and radiological threats might seem unlikely and not be in the tactical medic’s forethought. However, the use of these agents is an unfortunate but enduring reality. Acts of chemical, biological, or radiological terrorism are infrequent but have had very high visibility and a marked psychological impact. Extremists such as Iraqi insurgents, the Japanese Aum Shinrykio cult, and even government leaders such as Saddam Hussein have demonstrated willingness to develop and use these agents as well as conventional weapons to make their point (4, 5 and 6). These weapons can be used to attack offensively, threaten for negotiations, create public chaos, divert response resources, or facilitate escape. Alternatively, law enforcement agencies may use incapacitating chemicals as riot control agents. An example of this occurred in October 2002 when Russian forces used a fentanyl derivative to end a hostage situation in a theater (7). Unfortunately, this event resulted in several unintentional deaths among the hostages.

The tactical medic must be prepared to recognize when these agents are present, identify exposed personnel, and provide necessary field treatment, all the while protecting oneself and one’s team. Agents that rapidly kill or incapacitate are most likely to prevent the team from completing its mission so the tactical medic must be familiar with the effects of nerve agents, cyanides, choking agents, vesicants, and incapacitating agents. Agents with delayed onset, such as radioactive material, biologics, may not interfere with short missions but will require postevent decontamination and observation or quarantine.

This chapter provides an overview of the more serious chemical, biological, and radiological threats that the tactical medic may encounter. It focuses on recognition of exposure field treatment options and appropriate operational responses. Extraction and casualty transport are covered in other parts of the book.

SIGNS AND SYMPTOMS: IDENTIFYING EXPOSURE

In some cases your team may have intelligence about threats that will allow increased awareness and use of protective equipment at the start of the mission. During an operation you will need to constantly assess the situation for possible threats. Your team may carry chemical and/or radiological sensors. There is a variety of sensors available and many factors must be considered regarding their use (8). Chemicals can be identified with detection papers or air sampling devices. Radiation detection devices such as survey meters and dosimeters are discussed further in Chapters 40 and 41. The use of detection equipment requires training and maintenance programs. In the absence of good intelligence or detection equipment, presenting signs and symptoms will be your indicator that a team member has been contaminated.

Clinical identification of a chemical, biological, or radiological agent exposure is performed by assessing the signs and symptoms of those exposed as well as taking a good history. The history should always include when the signs and symptoms started and whether an odor was present at the scene. Depending on what the patient was exposed to, the onset of signs and symptoms will vary. For example, chemicals will primarily be quick-acting (minutes to hours), whereas biological agents may take days to weeks to manifest signs and symptoms, and radiological agents can take weeks to months for signs and symptoms to appear. Although an odor may not be a sensitive indicator due to the high level of olfactory variability in people, it may, when noted, still be a valuable clue as to agent presence and identification.

CHEMICAL AGENTS

Signs and Symptoms

Quick-Acting Chemical Agents

Depending on the amount and route of exposure, chemicals tend to act quickly, causing local or systemic
symptoms within seconds to hours (see Table 39.1). They can cause damage through skin contact, inhalation, or ingestion. Protection from chemical agents relies on the use of appropriate personal protection equipment with chemical filter masks and skin barriers. The chemical’s physical and pharmacological properties determine what risk the chemical poses. Chemicals that evaporate quickly or are volatile present a respiratory risk and chemicals that are persistent or oily may get on clothing and equipment and present a contact risk that might outlast the initial contact, so decontamination is extremely important. Always prenotify the hospital when bringing in a patient suspected of chemical contamination and notify them if any decontamination has already been performed.

TABLE 39.1. Chemical Agents.

*Agent*	*Signs and Symptoms*	*Onset of Action*	*Persistence*
Vesicant/blister agents	Blisters, erythema, pain	Seconds to hours	Persistent
Nerve agent	Seizures, shortness of breath, vomiting, diarrhea, miosis^a	Seconds to minutes	Volatile (GB) Persistent (VX)
Choking agents	Wheezing, pulmonary edema	Seconds to minutes	Volatile
Cyanides	Shortness of breath without cyanosis, seizures	Seconds to minutes	Volatile
^aMiosis: pinpoint pupils. Toxidrome for severe exposure is SLUDGEM: salivation, lacrimation, urination, defecation, gastrointestinal distress, emesis, miosis.

Seizures

If the patient is experiencing seizures, always check for hypoglycemia and determine if the patient has a history of seizures or if there was recent head trauma. With the patient not in a bright light, check the patient’s pupils; if the patient’s pupils are pinpoint (miosis), the chemical agent is likely to be one that affects the central nervous system. The most likely chemical group is acetylcholinesesterase inhibitors: nerve agents or a class of pesticide called an organophosphate. However, it could be an opioid incapacitating agent. Enlarged pupils may indicate the use of BZ or some other antimuscarinic incapacitating agent, but these generally do not cause seizures. If, however, pupils are normal or slightly dilated, and if the patient was in an enclosed space without good ventilation or airway protection, then the patient might have been exposed to cyanide. All personnel need to immediately move to fresh air upwind of the area and patients need to be treated according to the severity of their signs and symptoms (Table 39.1). If there is intelligence that suggests the team may be exposed to a nerve agent, particularly soman, pretreatment with pyridostigmine has been recommended but not been proven to be efficacious (9).

Nausea and Vomiting

If you or your team members are exhibiting pinpoint pupils, nausea, and vomiting, this could again be due to an exposure to an acetylcholinesterase inhibitor, that is, nerve agent or organophosphate. Move upwind, decontaminate, and treat appropriately (Fig. 39.1). However, if pupils are not pinpoint but team members are having nausea and vomiting, this could indicate another type of exposure such as high-dose radiation or low levels of phosgene vapor. Move out of the area to an upwind location, decontaminate your team members, and take them to the emergency department (ED) for further evaluation. Be sure to alert the ED staff that this could have been a chemical exposure and that the patient has already been decontaminated (you should make sure that your team member’s weapon has been secured prior to arrival at the hospital). Do not be surprised if the ED chooses to decontaminate the patient again.

Skin Burning and Blistering

Most of the time, blister/vesicant agents are persistent in the environment. They are oily in consistency so they remain in the environment for a long time, as well as on skin, clothing, and equipment (6). Until washed off, they continue to be a contact hazard for the patient as well as
for the tactical and health care team. Furthermore, if the chemical has been aerosolized or is volatile

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