The EMS Role in Chemical-Release Incidents

For almost a century, chemical agents have been used to horrific effect by legitimate governments and terrorist groups alike. On 16 March 1988, Iraqi Kurds living in Halabja, in the northern area of the country, were attacked by troops deployed by the Iraqi government, which used both nerve agents and conventional weapons to kill an estimated 5,000 of its own citizens. On 20 March 1995, a Japanese terrorist group known as Aum Shinriko released a nerve agent (sarin) into an Hbiya subway station in Tokyo, killing 12 people and hospitalizing more than 1,000. Even today, similar attacks causing only a small fraction of those numbers would overwhelm the average Emergency Medical Services (EMS) agency in even the largest city of almost any country in the world.

During the initial response – which is defined here as starting when an incident is first reported and ending when its true nature is recognized – the usually unspoken truth is that many responders themselves are likely to be among the victims. That candid admission, needless to say, is an unpopular statement in most healthcare agencies and organizations. However, its validity has been borne out in numerous exercises in which the participants were not pre-warned of the nature of the threat.

Largely for that reason, it has become evident that the most important actions that can be taken to improve the survival of the responders are: (a) improving their ability to recognize the nature of the threat earlier; and (b) requiring them, and training them, to promptly take the actions needed to protect themselves.

Recommended Antidotes and Deployment Options 

The usual role of EMS responders is to treat patients both on the scene and during their transportation to a healthcare facility – and, in responding to a chemical attack, to ensure that there are definitive antidotes available for nerve-agent poisoning. Atropine and Pralidoxime Chloride (also called 2-pam) are the recommended antidotes for such nerve agents as sarin, tabun, and what is called “the V series” of agents. These antidotes are already on the market, in the form of auto-injectors originally designed for military use. The auto-injectors are similar to the epi-pens carried by those who allergic to bee stings, and are used the same way – i.e., the user removes a safety cap and pushes the end of the “pen” against his or her leg, and the spring-loaded device delivers the medication.

There are two ways – “stockpile” and “distributed” – usually employed to ensure that these medications are quickly available at the scene of an incident in which a chemical nerve agent has been released, either accidentally or deliberately. New York City, to cite but one prominent example, uses a distributed plan, storing small caches of the medications on a relatively large number of vehicles assigned to local emergency services units throughout the city. The main advantage to using the distributed model of prepositioning is that the supply of antidotes builds as additional units arrive at the scene of the incident. In addition, having the overall supply spread around the entire city means that there is no central stockpile that can be attacked and/or otherwise destroyed.

There also is an important disadvantage – namely, that unless there is at least a minimum level of antidotes available on each vehicle that approximates the amount that the crew of that vehicle is likely to need, the response unit will frequently if not always be behind the curve in a number of situations requiring the dispatch of additional units to the scene for the sole purpose of bringing a larger supply of medications.

The other principal “availability” model is to keep most if not quite all antidotes in a large centralized stockpile that can be immediately mobilized at the time an incident is first reported. The principal advantage of this model is that a large amount of medications can be brought to bear very quickly without depending on additional units arriving at the incident scene. This model also facilitates coverage of a larger incident area with a smaller amount of medications and/or when EMS resources are relatively thin.

An Essential Supporting Role 

After the removal to healthcare facilities of all patients who can be saved there still remains the task of “cleaning up” the incident scene. EMS falls into a supporting role at this point, standing by not only to assist if new patients are discovered but also to support the efforts of other responders.

The support role varies, of course, in accordance with the plans developed and followed by different jurisdictions but typically might include both caring for injured rescuers and also evaluating the condition of responders who are about to enter extreme environments that would require such personal protective equipment as a “level-A” hazardous materials suit.

In short, whatever the nature of the incident – i.e., whether a release is accidental or intentional – EMS units have a critical role to play, not only in the immediate response to a nerve-agent release but also in treating the victims and supporting the ongoing rescue, control, and overhaul or clean-up efforts.