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Sunday, May 3, 2009

Responding to a CBRNE Event, by J. Paramedic

CBRNE is an acronym for Chemical-Biological-Radiological-Nuclear-Explosive events. [It is most commonly spoken "Sea-Burn"] This article gives a general guideline for responding to such incidents, geared toward the individual or small group with basic medical/trauma care abilities and little to no rescue capability. Some details about each type of event are also included. Note that I am a paramedic; my training is geared toward that venue, and this essay reflects that. However, many of the same principles are relevant to anyone forced by circumstances to respond to such incidents, not just public safety personnel.

Deliberate Attacks Versus Accidents
Most CBRNE events will be accidents or natural occurrences - chemical spills, pandemics, etc. Some, however, may be deliberate attacks. The most likely candidates are explosive devices, which are relatively cheap, do-it-yourself, low-risk endeavors. Chemical, biological, radiological and especially true nuclear attacks are expensive and high-risk. For example, creating a nuclear device requires obtaining plans, a large team of scientists in multiple specialties, esoteric materials, and so on. And that is just to build the device - a delivery system is still needed. Bringing these elements together is expensive, difficult and time-consuming, and likely to attract unwanted attention. Overall, the cost and risk-to-body-count ratio is much better with conventional arms and explosives; accordingly, these are the most likely forms of deliberate attack.

The first priority must always be making sure that you and yours do not become victims. If you become injured, you cannot help others; furthermore, you require assistance, which draws resources away from other victims. Consider the following:

Scene Safety: Look for fires, unstable structures, weapons or dangerous persons. Look up, down, and all around - remember that not all threats come from ground level. If you do not have the training or equipment to help safely, then wait for those who do. Leave the area if necessary. Do not try to provide aid in an unsafe area - move victims if necessary. In some cases, you may even have to leave them behind. Remember, you cannot help others if you become a casualty.

CBRNE events pose a high risk of contamination. Do not expose yourself to chemical or infectious agents or to radiation. If you do not have appropriate personal protection equipment (PPE) - do not approach the incident site. PPE is discussed in more detail later. Keep in mind the "Rule of Thumb" - get far enough away from the scene that you can completely cover it with your outstretched thumb. Remember to go uphill and upwind of the affected area.
Secondary Devices: In the case of a deliberate CBRNE attack, be aware that there could be additional threats or devices waiting for responders. While these are generally directed at police, fire, EMS or other official agencies, if you are trying to help, or have the bad luck to be at the scene, you share the danger.

In the case of CBRNE event, public safety agencies – police, fire and EMS – will have initial responsibility for scene management. Whatever you believe the long-term consequences will be, initially these agencies will be functioning. What follows is a description of their organizational model. If they are on the scene, you will be expected to function within that structure, if you are permitted to assist at all (for safety and liability reasons, you may not be). However, even if a CBRNE event occurs where public safety agencies cannot respond, the principles of this structure are still appropriate for your own use.

Overall responsibility for managing a given event will, at least initially, fall to a single person, designated as Incident Command. If the event can be managed with less than 7 or so responders, this person (and perhaps a Safety Officer) may be the only command personnel needed. However, a CBRNE event is likely to require a considerably larger response. It has been found that a single individual cannot effectively direct more than 3-7 people; 3-5 is an even better number. This is referred to as an effective span of control. Accordingly, for an event of large size, additional levels of organization will be introduced in order to maintain an appropriate span. Regional or functional divisions are used as necessary. For example, the Incident Commander may appoint a Rescue Chief, a Medical Chief, and a Fire Suppression Chief for a large-scale response. (Note that regional or functional elements and leaders are appointed by Incident Command. Some are standardized across the nation, while others will vary geographically depending on local organization, preference and tradition.) Each of these individuals will in turn direct about 3-5 subordinates. Depending on the number of responders, each of those subordinates could in turn direct a team of 3-5 responder, et cetera. The keys are that (1) each responder reports to one and only one supervisor, chief, or other leadership element; (2) each leader directs no more than 3-5 subordinates directly; and (3) overall responsibility for the scene falls to a single Incident Command. It is essential that there is no freelancing – a disorganized response can lead to inefficiency, an unsafe scene, oversights or mistakes resulting in poor outcomes, additional injuries [, needless contamination] or even deaths.

Geographically, a scene will be divided into three zones: a central hot zone, a surrounding warm zone, and a safe cold zone.
The hot zone is the immediate site of the incident, and may expand based on wind, spill or rainwater runoff, etc. Only trained responders with appropriate equipment should be in the hot zone. Depending on the incident type, this could mean fire department, HazMat or other type teams.
The warm zone surrounds the hot zone. Operating in the warm zone may also call for specialized training and equipment, but not always and not as much. Decontamination, which is discussed below, is usually performed in the warm zone.
Finally, the cold zone is the [ostensibly] safe area surrounding the warm zone. Basically this is the rest of the world. Additional resources and treatment centers will normally be located in the cold zone.

Decontamination will be necessary when it is likely that victims or responders have been exposed to chemicals, biological agents or radiation. The most common method of mass decon is gross decon. Essentially, victims are instructed to disrobe (it is estimated that in many cases this can remove up to 90% of contaminants) and are run through a large “shower” area, then given clean garments. On a smaller scale, you or your family members can self-decontaminate by disrobing and showering. It is recommended that garments that must normally be pulled over the head be cut off, instead. In some cases more detailed decon may need to be performed, for example a wound contaminated with radiological material. In this case, wash the specific site with soap and water, making sure not to contaminate others or other areas of the body while doing so (wear appropriate PPE). Note that victims should in most cases be decontaminated before receiving medical care or first aid. The exception is an immediate life-threatening condition, such as a severe hemorrhage, which may receive preliminary treatment prior to decon.

Personal Protective Equipment (PPE)

This discussion will deal with two forms of PPE: medical PPE and chemical protective gear. It is essential to wear appropriate PPE in any CBRNE event to avoid becoming contaminated or spreading contamination to others.
Medical PPE includes gloves, masks, gowns and eye protection. Follow the Universal Precautions philosophy – assume that everyone is a potential carrier of dangerous infections, and behave accordingly. Wear gloves whenever providing treatment, and change them between patients. Also be aware of the following “special” situations:

Splash protection – when “splashes” are anticipated (for example with childbirth, massive hemorrhage or vomiting) wear eye protection, a mask and a gown
Contact precautions – some infections, such as certain MRSA varieties, can be passed skin-to-skin, and call for contact precautions; wear gloves and a gown
Droplet precautions – infections spread in mucus or respiratory secretions may be transmitted over short distances by coughs and the like; wear a surgical mask when in close proximity. (The CDC says within three feet [but coughs can project droplets 10 feet or more.])
Airborne precautions – infections with airborne spread, such as tuberculosis, call for an N95 mask; ideally, the patient should be in a negative pressure room

Chemical Protective Equipment comes in four levels:
Level A calls for a Self-Contained Breathing Apparatus (SCBA) and a sealed chemical protective suit. Note that no single suit type protects against all forms of exposure. Generally, Level A protection is used only by trained HazMat Technicians.
Level B calls for an SCBA and a non-encapsulated (non-sealed) chemical protective suit, such as a Tyvek suit.
Level C consists of a filter-type respirator and chemical protective clothing, gloves and boots (same as type B).
Level D includes standard work clothes – uniforms, surgical scrubs, turnout gear – which give some skin/splash protection, and no respiratory protection.

Once proper PPE is in place, the response has been organized, and the scene has been rendered safe, care for victims can begin. After safety, preventing or minimizing the loss of life is the highest priority. A CBRNE event is likely to produce a large number of victims, and could easily exceed response capabilities. When this happens, the goal must be to do the greatest good for the greatest number.
Haphazardly rendering aid to random victims will result in chaos and poor treatment priorities, which will in turn lead to unnecessary loss of life or poor outcomes for victims. It is important to apply triage procedures. “Triage” simply means “to sort,” and refers to sorting victims into groups based on severity. The first competent care-giver to arrive at the scene of a mass casualty event should begin triaging – sorting – victims. The following categories are pretty much universally recognized:

Red or Immediate – These persons have severe injuries, but are likely to be able to be saved. The are “salvageable.” Given the seriousness of their condition, they receive treatment (and transport to the hospital, if available) first.
Yellow or Delayed – These are the people with serious but not life-threatening injuries. They are the second group to receive treatment, after the Reds/Immediates.
Green or Minimal – These are folks with only minor injuries. After all the reds and yellows are taken care of, they can be taken care of.
Black or Expectant – These victims are dead or expected to die. Any victim who cannot breathe on their own should be triaged into this category. If manpower or resources are limited, they should not be expended on these victims, who will probably not survive anyway.

Once triage is completed, treatment can begin.

Some comments specific to incident type will be included later. For now, consider the following general assessment and treatment priorities (note that this is a mere overview; detailed first aid skills should be sought elsewhere):
Mental Status – Assess whether the patient is awake, unresponsive, confused or lethargic, etc. An unresponsive patient should be considered Red/Immediate. A confused patient will probably be Yellow/Delayed, assuming no additional problems are found. Next check the ABCs:
Airway and Breathing – Check to see whether the victim is breathing. If not, open their airway by tilting the head or (if injury is suspected) by lifting the jaw forward. If the patient does not breath on their own at this point, consider them Black/Expectant. If they do, ask whether they are having difficulty breathing and listen to their breath. Difficulty breathing, rapid breathing or strange breathing sounds indicate at least a Yellow/Delayed patient. Severe or progressive difficulty breathing indicates a Red/Immediate patient.
Circulation – First, if a patient has no pulse, they are dead, and are Black/Expectant. Second, check for bleeding. If bleeding is found, it should be controlled. Place direct pressure on the site; this should control the bleeding. You may have to maintain pressure for several minutes, then place a dressing and bandage. If the bleeding does not stop, and is from an arm or leg, apply a tourniquet. In the past tourniquets were viewed with great caution, but it has been found that they can be safely used for up to several hours without long-term negative effects. At any rate, one cannot worry too much about an arm or leg when a victim – possibly a loved one – is bleeding to death. Finally, keep a bleeding patient warm (cover them with a blanket) and elevate their feet; this will help combat shock.

Those of you with CPR training will notice that I’ve omitted rescue breaths and chest compressions from this discussion. That’s because (1) in a mass casualty situation victims needing these interventions will be Black/Expectant, and will not be treated; and (2) unless high-level follow-on care – paramedic, ER and/or ICU – is available, CPR alone is unlikely to save a cardiac arrest victim. And I simply don’t have space to include such details here. I do, however, recommend that everyone seek out first aid and CPR training, at a minimum.

Finally, remember that scene safety comes before treatment. If necessary, move the victim. In general it is good to leave trauma victims in place, in case there is some spinal damage. However, when the scene is unsafe, you have to move.

Specific Incident Types

Explosives Events
Remember that explosive devices can also include some biological, chemical or radiological (“dirty bomb”) contaminant; and that there could be secondary devices waiting for responders. (Note that explosives will usually destroy any included biological or chemical material, making explosive dispersal of such agents unlikely to succeed.)
Explosives create blast-type injuries, which are classified as follows:
Primary Blast Injuries: pressure-related injuries from the blast wave, these can affect internal organs such as the intestines, lungs or inner ear without visible external injuries
Secondary Blast Injuries: these are injuries from objects (shrapnel, debris, etc.) striking the victim
Tertiary Blast Injuries: if a blast is powerful enough to throw a victim into the air, they will sustain injuries from striking the ground or other objects
Quaternary Blast Injuries: all other injuries, including burns and the like

Here are some basic treatment ideas:
Bleeding should be controlled by direct pressure and, if necessary, tourniquet.
Broken bones, sprains, etc., can be splinted
Burns should be covered with clean – preferably sterile – sheets or dressings; do not put any salves or chemicals on any but minor burns, as they will have to be washed out later – very painful for the victim
Victims with neck or back pain or tenderness, or loss of sensation or movement, should not be moved unless absolutely necessary, as they may have suffered spinal injury, which may be worsened by movement. However, this is much less likely than television and first aid instructors would have you believe.

Chemical Events
Chemical events require proper PPE; otherwise, follow the “Rule of Thumb.” Remember that wind and water run-off can spread contaminants. Also remember that chemical events may not be immediately apparent. Multiple victims with quickly-developing symptoms, as well as dead flora or fauna in the area, are the most likely signs.

A special note should be made for organophosphates. These produce a condition commonly called SLUDGE (salivation, lacrimation, urination,
diarrhea, gastrointestinal distress, and emesis), which in layman's terms is the sudden onset of soiling yourself, peeing on yourself, crying and vomiting everywhere. They merit special mention because these are the type of exposures for which Mark I kits and other atropine/2-PAM kits are indicated, as well as valium for possible seizures.

Biological Events
Biological events can be difficult to detect, and to protect against, because often there is no scene. Generally, multiple victims will present with “flu-like symptoms” or other complaints to multiple health care providers. The main signs are multiple patients with similar complaints, especially when the symptoms, the demographics, or the season are unusual. For example, large numbers of healthy young people complaining of flu symptoms in the middle of summer, clustered in certain areas, is a sign of an exposure or pandemic. Isolating the source is a matter of finding “common ground” between the victims – think of lots of people suffering from nausea, vomiting and diarrhea after eating at the same restaurant.

Speaking of flu-like symptoms, I thought it might be timely to share with you the following guidance that I’ve received from my EMS agency regarding the current “Swine flu” –

1. Suspect swine flu in a person who:
- has a cough, runny nose or sore throat; and
- has a fever more than 101.4F; and
- has been to an “endemic area” in the last 7 days
Endemic areas currently include Mexico and affected areas of the USA.
2. Distance is considered adequate protection; however, if one must approach a suspected swine flu patient, a surgical mask is recommended.
3. Only if one must be in a confined space with a suspected swine flu patient is an N95 respirator recommended.
These recommendations come from our medical director based on CDC and other agencies’ information and advice.

Victims of a biological agent (i.e., an illness) can often be treated, depending on the agent; preventing further spread within a population can usually only be accomplished by isolation or – on large scales – by quarantine.

Nuclear or Radiological Event
As noted previously, deliberate nuclear attacks are relatively unlikely, due to their expense and risk when compared with conventional methods. “Accidents” are also rare, as modern-day reactors and the like are designed with multiple redundancies and dead-man’s-switches. We are many years removed from the technologies of Chernobyl and Three Mile Island, or so experts say. Smaller radiological events are more likely. Of course the first thought in most minds is the “dirty bomb,” a conventional explosive with radioactive material.

Radioactive materials are usually divided according to the following types:

Alpha particles cannot penetrate clothing or often even skin; however, they are very dangerous if somehow introduced into the body
Beta particles can be absorbed by protective clothing
Gamma rays are stopped only by several inches of lead [or several feet of earth or concrete], and easily penetrate human beings, damaging organs along their paths.

The severity of radiation exposure will depend on time, distance and shielding – a shorter exposure, over a greater distance, with more shielding in between, will be less severe than the opposite. Radiation effects various bodily systems. Inhaled radioactive material can damage the lungs. Radiation can also produce severe burns; these will present as severe itching, but over time will reveal significant damage.
In evaluating the severity of radiation exposure, the easiest reliable measure is time to onset of vomiting. If a victim starts vomiting within one hour of exposure, their exposure is severe. Beyond two hours, exposure is probably mild to moderate.
You may find it useful to stock geiger counters, personal dosimeters, or potassium iodide (KI) for your family. Information on all of these topics is already archived on SurvivalBlog, so I will not go into them here.
Otherwise, without specialized facilities, the best you can do for a victim of radiation poisoning is to decontaminate and treat symptoms as they arise. Remember that with a sufficient dose of radiation the victim can themselves become a source of radiation, and pose a contamination risk.

In the case of a CBRNE event, essential include a scrupulous eye to safety, an organized response, careful use of personal protective equipment (PPE) and decontamination to prevent spread of contamination, triage of victims, and the best treatment available. Remember that you will probably not be able to do as much as you would like. You must do the greatest good for the greatest number. Finally, remember your priorities: after safety, preventing the loss of life comes first. Then you can worry about protecting property and/or the environment, and long-term recovery. These topics, however, are beyond the scope of this essay. I hope you find the information contained here useful in your preparations, though I hope you never have to use it in a true CBRNE event.


1 comment:

  1. No one outside (and few inside) the US says "See-burn" what a ludicrous load of b*****ks churned up once again by a few operations-heads Americans trying to sound cool. Be professional and spell it out for pity's sake!