Ch15_pg511-526.pdf

Triage of Chemical Casualties

Chapter 15

TRIAGE OF CHEMICAL CASUALTIES

Shirley D. TuorinSky, MSn * ; Duane C. Caneva, MD † ; a n d FreDeriCk r. SiDell, MD ‡

InTROdUCTIOn

TRIAGE PRInCIPLES And PROCESSES

Levels of Care

decontamination

Treatment, decontamination, and Transport Linkage

TRIAGE CATEGORIES FOR CHEMICAL CASUALTIES

US Military Triage Categories

Other Triage Systems

MEdICAL MAnAGEMEnT OF CHEMICAL CASUALTIES

nerve Agents

Cyanide

Vesicants

Lung-damaging Agents

Incapacitating Agents

Riot Control Agents

TRIAGE BY CATEGORY And AGEnT

Immediate

delayed

Minimal

Expectant

CASUALTIES WITH COMBInEd InJURIES

nonpersistent nerve Agents

Persistent nerve Agents

Vesicants

Lung-damaging Agents

Cyanide

Incapacitating Agents

SUMMARY

* Lieutenant Colonel, AN, US Army; Executive Officer, Combat Casualty Care Division, US Army Medical Research Institute of Chemical Defense, 3100

Ricketts Point Road, Aberdeen Proving Ground, Maryland 21010-5400

† Head, Medical Plans and Policy, Navy Medicine Office of Homeland Security, 2300 E Street, NW, Washington, DC 20372

‡ Formerly, Chief, Chemical Casualty Care Division, and Director, Medical Management of Chemical Casualties Course, US Army Medical Research

Institute of Chemical Defense, Aberdeen Proving Ground, Maryland

511

Medical Aspects of Chemical Warfare

InTROdUCTIOn

The term “triage” has come to have different mean-

ings depending on the situation in which it is used.

Derived from the French word trier, meaning to sort,

categorize, or select, its initial use is thought to have

been in reference to the sorting of crops according to

quality. Triage soon became used on the battlefield as

the sorting of casualties into three groups: (1) those

needing immediate care, (2) those who could wait

for treatment, and (3) those not expected to survive.

Military triage has certain definitions codified in

doctrine and policy. The term also refers to the initial

screening and prioritization process in emergency

departments.

Triage is one of the most important tools in the han-

dling of mass chemical casualties. Triage criteria must

be relevant to the available medical units’ capabilities,

and triage process should be planned in advance and

practiced. in general, triage is performed at naturally

occurring bottlenecks, where delays in medical care

may occur, and when medical requirements exceed

capabilities or resources, which may cause a breech in

the standard of care. The ultimate goal of triage is to

optimize the use of available medical resources to pro-

vide the best medical care possible by identifying the

correct priority of patients. 1 This chapter will focus on

the process of triage in chemical agent mass casualties.

Specific chemical warfare agent classes, current triage

systems, and classifications of triage will be reviewed,

with discussion of issues specific to the battlefield and

installation setting.

TRIAGE PRInCIPLES And PROCESSES

in a mass casualty situation, whether in peacetime

or on a battlefield, triage is carried out to provide

immediate and appropriate care for casualties with

treatable injuries, to delay care for those with less

immediate needs, and to set aside those for whom

care would be too timely or asset-consuming. Triage

ensures the greatest care for the greatest number and

the maximal utilization of medical assets: personnel,

supplies, and facilities. To effectively triage a given

population, a triage officer should know the following

essential information:

surgeons must spend time in the operating suite, and

their available time to perform triage will be limited

beyond the initial efforts and between operations.

additionally, the expertise of surgical triage applies

to traumatic injuries, and may not be as applicable to

chemical incidents. Commonly , the most experienced

combat medic performs triage; however, other physi-

cians, dentists, or nurses with appropriate training and

experience can also accomplish this arduous task.

Part of the triage process is the evaluation of the

benefit that immediate assistance will provide. This

evaluation is based, in part, on the natural course of

the injury or disease. For example, dedicating medical

assets to a casualty with an injury that will either heal

or prove fatal no matter what immediate care is given

would be of little benefit. another part of the process is

considering the overall tactical mission requirements,

which may change rapidly in the battlefield setting.

The ultimate goal of combat medicine is to return the

greatest possible number of soldiers to combat and the

preservation of life, limb, and eyesight in those who

must be evacuated. 3

Setting aside casualties who are in need is unpopu-

lar among medical care providers, and poses an ethical

dilemma on how to provide the ultimate care for each

patient. The hippocratic oath is not helpful in this

sorting process, because the modern interpretation of

the oath states that the duty of physicians and nurses

is to protect and promote the welfare of their patients.

Furthermore, according to the oath, caregivers must

focus their full attention on that patient until the

patient’s needs are met, before turning their attention

to another patient. additionally, in peacetime, every

patient who enters the hospital emergency room

• The current environment and potential threat,

course, and harm. Situational awareness must

include current tactical goals and conditions,

the potential evolution of hazardous materi-

als or conditions, and the impact these might

have on the patients and providers.

• The ongoing medical requirements, including

the number and type of current casualties and

potential population at risk.

• The medical resources on hand.

• The natural course of a given injury.

• The current and likely casualty flow.

• The medical evacuation capabilities.

• The decontamination requirements in a chemi-

cal incident.

according to FM 8-10, Health Service Support in a

Theater of operations, 2 the triage officer should be a

highly experienced medical provider who can make

sound clinical judgments quickly. ideally, a surgeon

experienced with combat trauma would be used in

this capacity; however, once casualty flow progresses,

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Triage of Chemical Casualties

receives the full attention of all personnel needed to

provide optimal care. For these reasons, the thought

of setting aside a critically sick or injured patient may

well be repugnant to someone who has not been in a

mass casualty situation or who has given little thought

to such situations. 4

in addition to knowing the natural course of the

disease or injury, the triage officer should also be

aware of current medical assets, the current casualty

population, the anticipated number and types of in-

coming casualties, the current status of the evacuation

process, and the assets and casualty population at the

evacuation site. Committing assets to the stabilization

of a seriously injured casualty in anticipation of early

evacuation and more definitive care would be point-

less if evacuation could not be accomplished within

the time needed for the casualty’s effective care, or

if the assets at the evacuation site were already com-

mitted. The officer might also triage differently if, for

example, he or she knew that the 10 casualties present

would need care in the next 24 hours, or, on the other

hand, that those 10 casualties were to be followed by

50 more within an hour. 5 in an unfavorable tactical

situation, another consideration may arise: casualties

with minor wounds, who otherwise may be classified

minimal, might have highest priority for care to en-

able them to return to duty. The fighting strength thus

preserved could save medical personnel and casualties

from attack.

casualty set aside as expectant (see Triage Categories

for Chemical Casualties, below, for definitions of

classification groups) because personnel are occupied

with more salvageable casualties might be reclassi-

fied as immediate when those personnel become free.

on the other hand, a casualty with a serious but not

life-threatening wound, initially classified as delayed,

could suddenly develop unanticipated bleeding and,

if treatment assets were available, might be retriaged

as immediate.

even in the most sophisticated medical setting, a

form of triage is usually performed (perhaps not al-

ways consciously): separation of those casualties who

will benefit from medical intervention from those who

will not be helped even by maximal care. however, in

most circumstances in a large medical facility, care is

administered anyway; for instance, an individual with

a devastating head injury might receive life-support

measures. The realization that in some settings assets

cannot be spent in this manner is an integral part of

triage. 6

decontamination

at the first level of medical care, the chemical casual-

ty is contaminated, and both the casualty and the triage

officer are in protective clothing (mission oriented pro-

tective posture [MoPP] level 4 or occupational Safety

and health administration level C). Furthermore, the

first medical care given to the casualty is in a contami-

nated area, on the “hot” or dirty side of the “hotline” at

the emergency treatment station (see Chapter 14, Field

Management of Chemical Casualties). This situation is

in contrast to any level of care in which casualties were

previously decontaminated, and to a conventional

situation with no contamination involved. examina-

tion of the casualty is not as efficient or effective as it

might be in a clean (not contaminated) environment,

and very little care can be given to a casualty in the

emergency treatment section in the contaminated area.

in a chemically contaminated environment, in contrast

to other triage situations, the most experienced medical

staff work in the clean treatment area, where they can

provide maximum care.

it is extremely unlikely that immediate decontami-

nation at the first level of medical care will change

the fate of the chemical casualty or the outcome of the

injury. various estimates indicate that the casualty

usually will not reach the first level of care for 15 to

60 minutes after the injury or onset of effects, except

when the medical treatment facility (MTF) is close to

the battle line or is under attack and the injury occurs

just outside. The casualty is unlikely to seek care until

the injury becomes apparent, which is usually long

Levels of Care

Triage is a dynamic rather than a static process,

in which casualties are periodically reevaluated for

changes in condition and retriaged at various levels

of medical care, ranging from the battlefield to the

battalion aid station to the combat support hospital.

The first triage is done by the corpsman, medic, or unit

combat lifesaver in the field. The medic first evaluates

the severity of injury and decides whether anything

can be done to save life or limb. if the answer is no,

the medic moves on, perhaps after administering an

analgesic. More commonly, the medic decides that

care is indicated. Can the medic provide that care on

the spot to return the service member to duty quickly?

Can the care wait until the battle is less intense or an

ambulance arrives? or must the care be given imme-

diately if the casualty is to survive? in the latter case,

the medic ensures that the casualty is transferred to

the medical facility if possible.

a casualty is triaged once more upon entry into a

medical care facility, followed by repeated triage within

the facility as circumstances (eg, the casualty’s condi-

tion and the assets available) change. For example, a

513

Medical Aspects of Chemical Warfare

after exposure. For example, mustard, a vesicant, may

be on the skin for many hours before a lesion becomes

noticeable. Thus, it is likely that the agent has been

completely absorbed or has evaporated from the skin

by the time the casualty reaches the MTF, and the small

amount unabsorbed, or absorbed during a wait for

decontamination, is very unlikely to be significant.

The process of patient decontamination must be fac-

tored into the triage decision. (it must be remembered

that triage refers to priority for medical or surgical

care, not priority for decontamination. all chemical

casualties require decontamination. although a ca-

sualty exposed to vapor from a volatile agent such as

cyanide, phosgene, or a nerve agent may not appear

to need decontamination, verifying that no liquid is

present on the casualty is difficult.) in a contaminated

environment, emergency care is given by personnel

in MoPP 4, the highest level of protective gear, which

limits their capabilities. after receiving emergency

care, a casualty must go through the decontamina-

tion station before receiving more definitive care in

a clean environment. Decontamination takes 10 to 20

minutes. as a rule no medical care is provided during

this time or during the time spent waiting to begin the

decontamination process. Therefore, before leaving the

emergency care area, patients must be stabilized to an

extent that their condition will not deteriorate dur-

ing this time. if stabilization cannot be achieved, the

triage officer must consider this factor when making

the triage judgment. if the casualty has torn clothing

or a wound suspected to be the source of contamina-

tion, a different type of decontamination—immediate

decontamination—must be performed at the triage or

emergency treatment station in the dirty or chemically

contaminated area.

Casualties exposed to certain chemical agents such

as nerve agents may be apneic or nearly apneic; one of

the first interventions required is assisted ventilation.

Special, air-filtering assisted ventilation equipment, a

chemical mask-valve-bag device (called resuscitation

device, individual chemical), is available for use in a

chemical environment. however, personnel available

to provide ventilator assistance in the contaminated

environment are likely to be limited. also, if a brisk

wind is present and the medical facility is far upwind

from the source of contamination, very little agent

vapor will remain in the air. if no air-filtering ventila-

tion equipment is available, medical personnel must

decide whether to ventilate with air that is possibly

minimally contaminated or let the casualty remain

apneic. once assisted ventilation is begun, the care

provider is committed to the process and cannot care

for other casualties, so the number of medical person-

nel available in the contaminated area influences the

ventilation decision. however, a walking wounded

casualty (in the minimal category) can quickly be

taught how to ventilate other casualties. 7

Treatment, decontamination, and Transport Linkage

Triage is always linked to treatment; in a mass

casualty event, triage and treatment are also linked to

transport. in a chemical weapons mass casualty event,

decontamination is also linked, and transport is from

the contaminated environment. This linked process

occurs at the incident site, and is somewhat duplicated

at the MTF; however, different statutory codes, poli-

cies, and requirements are relevant in each place. as

the preparedness and response efforts for homeland

security mature, the tactics, techniques, and procedures

used in military settings or homeland settings are con-

verging. likewise, the regulatory statutes, including

best practices, certification processes for equipment,

training, and competencies, are showing a pattern of

convergence. Further alignment should be driven by

such initiatives as development of national resource

typing systems (discussed in other Triage Systems,

below) in support of national preparedness goals.

During response preparations, the triage and treat-

ment teams are best placed at naturally occurring

bottlenecks as patients are processed through the

decontamination corridor (Figure 15-1). at least three

triage locations should be placed at the incident site.

Triage and treatment teams must integrate their work

with patient transport teams (litter bearers and ambu-

lance staff). They must also integrate with decontami-

nation teams, which may be comprised of personnel

with very limited medical training. Medical oversight

of the patients must be clearly defined and understood

by all personnel, including recognition of and proper

alerts for changes in patient condition, continuation

of any supportive measures, and strict adherence to

protocol and procedure.

The initial casualty collection point is located near

the border of the hot and warm (contamination reduc-

tion) zones. This location allows for initial collection

of nonambulatory victims from the incident site in

the hot zone and provides shorter distances and cycle

times for teams retrieving the casualties from the inci-

dent site. it also provides a working environment for

medical personnel who are initially uncontaminated.

antidote administration and airway management

are the mainstays of treatment at this point. The next

bottleneck generally occurs on both sides of the decon-

tamination shelter. Current methods for mass casualty

decontamination allow for very limited throughput,

even by the most experienced of teams with the best

technology, leading to a backup of patient flow at the

514

Triage of Chemical Casualties

entrance. These “decon triage” teams provide retriage

and basic treatment including airway management,

additional administration of antidote, and perhaps

more invasive medical intervention.

on the clean side of the decontamination shelter is

another typical bottleneck as patients await transport

from the incident scene to more definitive treatment

facilities. here, medical personnel are not encumbered

with personal protective equipment and are able to

evaluate patients in an uncontaminated environment.

More invasive medical intervention is possible with-

out concern for further contaminating the patient. a

balance among condition, transport times, medical

resources, and interventional requirements must be

sought in the prioritization and triage of the patients.

in incidents conducted in a noncombat situation, such

as might occur on an installation during peacetime,

first responders adhere to federal statutes for training

qualifications. 8

a somewhat similar scenario occurs at the MTF

(see Figure 14–12 ). at the MTF, training requirements

are governed by different regulations than those for

the incident site. For example, current occupational

Safety and health administration guidelines require

8 hours of hazardous waste operations and emergency

response (haZWoPer) first responder operations

level training for first receivers who are expected

to decontaminate victims or handle victims before

they are thoroughly decontaminated at the MTF. The

guidelines include additional criteria for the personal

protective equipment levels recommended (level C),

no more than a 10-minute time period from patient

exposure at the incident site to presentation to the

MTF, and a thorough hazard vulnerability assessment

to identify specific threats or hazards that might drive

additional requirements. additionally, the hazard-

ous zones are recognized as different from those at

the decontamination incident site, referred to as the

“warm (contamination reduction) zone” and “cold

(postdecontamination) zone” (see Figure 14-12). at

Chemical Incident Site Setup

Chemical

Incident Site

Initial

Fire Dept/EMS

Hot (Exclusion)

Zone

Casualty

Collection

Point

Hot Zone

Coordinator

Hot Zone

Assembly Area

First Responder Flow

Casualty Flow

Triage and Treatment Groups

Decon

Triage

Warm

(Contamination

Reduction)

Zone

Waste Water

First Responder

Decon Lane

Water Source

Medical Triage

& Treatment

Incident

Command

Post

Entry/Exit

Control

Point

Water Heater

Cold

Zone

Staging

Area

EMS

Reconstitution of

supplies/equipment

and personnel

Hospital

Emergency Operations

Center (EOC)

Cold (Support)

Zone

EMS Transport Group

Fig. 15-1 . national site setup and control zones for a hazardous materials site. all distances are notional.

eMS: emergency medical service

Diagram: Courtesy of Commander Duane Caneva, uS navy.

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