Agency for Toxic Substances and Disease Registry
Case Studies in Environmental Medicine (CSEM) 

Cholinesterase Inhibitors
Including Insecticides and Chemical Warfare Nerve Agents
Part 1: Community Preparedness for Mass Casualty Events Involving Cholinesterase Inhibitors

Learning Objectives

Upon completion of this portion of the case study, you should be able to:

• Identify key community agencies that should be involved in planning, training, and exercises for hazardous materials emergencies and disasters, such as those due to exposure to cholinesterase inhibitors.
• Describe the consequences that result when many patients exposed to hazardous materials, such as cholinesterase inhibitors, transport themselves to the hospital.

Introduction

As the case presentation illustrates, cholinesterase inhibitors can be involved in mass casualty events. A notable example was the Sarin attack on the Tokyo subway in 1995. The ability to provide good clinical care, especially when multiple casualties are involved, requires good organizational management and planning activities at both the institutional and community level.

Misconception

Each hospital should develop a plan for dealing with cholinesterase inhibitor exposed patients.

Reality

Effective management of these cases requires planning, training, emergency communications, and coordination at the community level.

Need for Community Level Planning, Training, and Drills

The response to hazardous materials emergencies and disasters requires planning, training, exercising, and coordination at the community level.(Auf der Heide 1989; Auf der Heide 2002; Auf der Heide 2006)

At a minimum, the following organizations should be involved:

• All area hospitals.
• All area emergency medical services (e.g., ambulance) agencies and providers.
• Emergency management/disaster offices.
• Environmental protection offices.
• Fire departments.
• Law enforcement agencies (including FBI).
• Metropolitan Medical Response Systems (MMRSs). (For more information go to http://mmrs.fema.gov).
• Public health agencies.
• The Local Emergency Planning Committee (LEPC) required under the Superfund Amendments and Reauthorization Act (SARA) Title III laws for hazmat preparedness. For more information go to http://yosemite.epa.gov/oswer/ceppoweb.nsf/content/epcraOverview.htm
• The poison center

Coordination of Community Personnel

Response issues that require community-wide coordination and communication include the need for someone that will coordinate personnel responsible for:

• Evacuating/sheltering-in-place of community medical facilities (if required).
• Notifying hospitals of an incident involving hazardous materials (such as nerve agents or pesticides).
• Field medical and public health response units.
• Deciding when to issue an order for the public to evacuate or shelter-in-place.
• Distributing of large amounts of antidotes among the area medical facilities (if needed).
• Dissemination of information (e.g., via the mass media) that will help the public protect itself.
• Tracking and releasing of the information needed to address massive inquiries about the missing.

The Importance of Evidence-Based Planning

Dealing with victims exposed to hazardous materials, such as cholinesterase inhibitors, requires effective planning at both the institutional and community level. However, the effectiveness of planning is only as good as the assumptions upon which it is based.

While the existing empirical literature on medical responses to hazardous material emergencies and disasters is limited, both in its extent and quality, there are some important findings relevant to planning. A number of these are not specific to, but are applicable in, cases of cholinesterase inhibitor exposure. These are discussed below.

Misconception

Hospitals should work with local fire departments and EMS providers to encourage them to decontaminate patients contaminated with cholinesterase inhibitors in the field before transporting them to hospitals.

Reality

Available studies indicate that many chemically exposed patients arrive unannounced at the closest hospitals after being transported by themselves or bystanders - effectively bypassing the EMS system and any field attempts at decontamination. This is true in routine emergencies as well as in disasters. Therefore, every hospital must be prepared to decontaminate casualties, and to do so with little or no advanced warning.

Patient Self-Transport

While it may be assumed that patients will enter the hospital by way of the local emergency medical services system, often many patients will get to the hospital by their own means. (Geller, Singleton et al. 2001; Vogt and Sorensen 2002; U.S. Occupational Safety and Health Administration 2005; Okumura, Suzuki et al. 1998) This pattern is common in disasters as well (Murakami 2000; Auf der Heide 2006)

As a result:

• Patients may arrive without notice. (Auf der Heide 2006)
• Patients may arrive without having been triaged. (Auf der Heide 2006; Okumura, Suzuki et al. 1998)
• Patients may be placed in an exam room before it is discovered that they have been exposed to a hazardous substance. (Lambert 1996; Geller, Singleton et al. 2001)
• Patients may arrive without having been decontaminated, and hospital staff may become secondarily contaminated. (Lavoie, Coomes et al. 1992; Nozaki and Aikawa 1995; Okudera, Morita et al. 1997; Trutt and Oster 1999; Geller, Singleton et al. 2001; Horton, Berkowitz et al. 2003; Okumura, Suzuki et al. 1998)
• Patients may tend to converge on the closest or most locally renowned hospitals. (Auf der Heide 2006; Okumura, Suzuki et al. 1998)
• Timely information on the chemical(s) to which they have been exposed may be lacking.

Planning Implications of Self-Transport

Hospitals may be the first emergency response organizations to learn of an incident involving chemically contaminated casualties. They need to see to it that others are notified, too. For example, the 911 dispatcher needs to be notified, so that she can relay the information to ambulances and other emergency personnel at the scene. Other hospitals should be notified, so they can hopefully have some lead time to don personal protective gear and set up decontamination equipment before they start receiving casualties. The chief, in-house, acting administrator needs to be notified so that the hospital disaster plan can be activated. The poison center should be notified, since it may be receiving calls about the incident.

Hospitals may have to deal with contaminated casualties before they have had time to don personal protective equipment or set up decontamination showers and equipment.

It may be advantageous to have an expedient decontamination procedure until this can be done. One approach may be to have fire hoses and spray nozzles hooked up to a high-capacity, low-pressure, warm-water supply. Then, as a temporizing measure, contaminated victims could be sprayed from a distance without exposing hospital staff to contaminants, or exposing the victims to hypothermia when the weather is inclement.

There is an advantage to having decontamination facilities permanently set up, rather than using equipment that must be set up after a patient arrives.

Since it is patients, rather than the emergency medical services system, that often determine hospital destination, all hospitals must have the capacity to deal with contaminated casualties.

Key Points

• The response to hazardous materials emergencies and disasters requires planning, training, exercising, and coordination at the community level. This may involve several organizations.

Progress Check