CHAPTER 10 Major incident management and triage 598 Performing a radio check - Radio checks can be initiated by control or any call sign - Begi n with the stations being called, then your station, then radio check ( \200\230all stations zulu from control, radio check over \200\231) Reply with your call sign and OK if reception is clear ( \200\230Zulu 1, OK, over \200\231) The initiator ends the radio check with his call sign OK and out ( \200\230Control, OK, out \200\231 ) Other terms are used for unclear transmission: Difficult \200\224can be understood but not clear (interference) Broken \200\224message onl y heard intermittently Unworkable \200\224occasional words only or continuous interference Nothing heard. This page intentionally left blank CHAPTER 10 Major incident management and triage 600 Sources of further information Arrangements for responding to nuclear emergencies. Health a nd Safety Executive. Available from the Stationery Office Dealing with disaster, Rev 3rd edn. Brodie Publishing. Available from the Stationery Office (Contains an extensive list of useful website addresses covering all aspects of major inci dent response.) Emergency planning in the NHS \200\224health service arrangements for dealing with major in cidents. Available from Department of Health Emergency Planning Coordination Unit, Room 603 , Richmond House, 79 Whitehall, London SW1A 2NS Guidelines for faith communities when dealing with disasters. Available from the Church of England Board for Social Responsibility, Church House, Great Smith St, London SW1P 3NZ Major Incident Medical Management and Support (MIMMS), 2nd edn. Advanced Life Support Group , BMA Publications. Military aid to the civil community 3rd edn (1989). Available from the Stationery Office This page intentionally left blank CHAPTER 10 Major incident management and triage 602 Triage Introduction Triage is the sorting of patients, by priority, for treatment or transp ortation. It is a dynamic process. Primary triage is carried out in the bronze area, second ary triage at the casualty clearing station. Triage may be repeated before evacuation of pa tients from the site (triage for transportation). Triage is the sorting of patients, by priority, for treatment or transportation Triage priorities Common triage priorities P T Description Color 1 1 Immediate Red 2 2 Urgent Yellow 3 3 Delayed Green 1 Hold 4 Expectant Blue Dead Dead Dead White or black In the UK, the T system is conventionally used at a major incident. Immediate priority These casualties require immediate life-saving intervention. Urgent priority These casualties require significant intervention within 2 \200\2234 hours. Delayed priority These casualties require intervention, but not within 4 hours. Expectant priority Treating these casualties at an early stage in the incident would divert resources from potentially salvageable casualties, with no significant chance of a success ful outcome. The expectant category can be marked by: Use of a blue card (not usually available) - Amending a P3 card with the word expectant - T urning down the corners of a P3 green card diagonally to expose a red card underneath. This page intentionally left blank CHAPTER 10 Major incident management and triage 604 Triage sieve The triage sieve is a simple reproducible triage method for use as a primary t riage tool (see Fig. 10.7). No DELAYED Treatment 3 DEAD Uninjured Walking Yes Survivor reception center No No Breathing ? Breathing ? Open the airway No Yes Yes Respiratory rate ? Less than 10 or more than 30 Yes IMMEDIATE Treatment 1 No Pulse rate ? Less than 40 or more than 120 Yes URGENT Treatment 2 No Fig. 10.7 The triage sieve. Reprinted with permission from Greaves I et al. (2005) Emergenc y care: a textbook for paramedics, 2nd edn. W.B. Saunders Co. Ltd. This page intentionally left blank CHAPTER 10 Major incident management and triage 606 The triage sort The triage sort is a more complex system designed for use at the casualty c learing station. However, if there are insufficient staff to deal with patients arriving at the CCS, the sieve can be repeated until it becomes possible to carry out the sort. The tr iage sort uses the triage revised trauma score. A coded score is derived for each of the three variables (respiratory rate, systolic BP, an d Glasgow Coma Score Scale). The three coded values are then added together, and the final triage priority is derived as shown in the box. THE TRIAGE SORT1 607 The triage sort PHYSIOLOGICAL VARIABLE Respiratory rate VALUE 10 \200\22329 >29 SCORE 4 3 6 \200\2239 1 \200\2235 0 2 1 0 Systolic blood pressure >90 76 \200\22389 50 \200\22375 1 \200\22349 0 4 3 2 1 0 Glasgow Coma Scale Score 13 \200\22315 9 \200\22312 6 \200\2238 4 \200\2235 3 4 3 2 1 0 Total score for coding (see box below) X Coded score 1 \200\22310 11 12 0 Priority T1 T2 T3 Dead CHAPTER 10 Major incident management and triage 608 Triage in children The normal physiological values given in the triage sieve on p.609 do no t apply in children and must, therefore, be adapted. Specific triage sieve protocols can be used, based on the child \200\231s length (top of head to feet) or weight: Weight = (2 x age in years) + 8 Alternatively, a pediatric triage tape can be used. This is placed along- side the child an d the appropriate triage sieve protocol read off the tape according to the child \200\231s length. TRIAGE IN CHILDREN1 609 Alert and moving all limbs DELAYED PRIORITY 3 Yes DEAD No No No Open airway Breathing Breathing Yes Yes <20 OR >50 IMMEDIATE PRIORITY 1 Respiratory rate 20 \200\22350 No Capillary refill <2 seconds (use forehead) Pulse rate <90 OR >180 90 \200\223180 Yes URGENT Priority 2 SEND UNINJURED SURVIVORS TO SURVIVOR RECEPTION center Fig. 10.8 Triage sieve 1: child 50 \200\22380cm or 3 \200\22310kg. Reprinted with permissio n from Hodgetts and Porter (2002). Major incident management system, 2nd edn. BMJ Books. CHAPTER 10 Major incident management and triage 610 Alert and moving all limbs DELAYED PRIORITY 3 Yes DEAD No No No Open airway Breathing Breathing Yes Yes <15 OR >40 IMMEDIATE PRIORITY 1 Respiratory rate 15 \200\22340 No Capillary refill <2 seconds (use forehead) Pulse rate <80 OR >160 90 \200\223160 Yes URGENT Priority 2 SEND UNINJURED SURVIVORS TO SURVIVOR RECEPTION center Fig. 10.9 Triage sieve 2: child 80 \200\223100cm or 11 \200\22318kg. Reprinted with permiss ion from Hodgetts and Porter (2002). Major incident management system, 2nd edn. BMJ Books. TRIAGE IN CHILDREN1 611 Alert and moving all limbs DELAYED PRIORITY 3 Yes DEAD No No No Open airway Breathing Breathing Yes Yes <10 OR >30 IMMEDIATE PRIORITY 1 Respiratory rate 10 \200\22330 No Capillary refill <2 seconds (use forehead) Pulse rate <70 OR >140 70 \200\223140 Yes URGENT Priority 2 SEND UNINJURED SURVIVORS TO SURVIVOR RECEPTION center Fig. 10.10 Triage sieve 3: child 100 \200\223140cm or 19 \200\22332 kg. Reprinted with perm ission from Hodgetts and Porter (2002). Major incident management system, 2nd edn. BMJ Book s. CHAPTER 10 Major incident management and triage 612 Triage labeling Because a patient \200\231s condition may improve (for example, with treat- ment) or deteriorate, any effective triage labeling system must allow re-categorization. I t is also helpful if clinical notes can be made on the triage card since this will prevent duplication and potential loss of records. Various triage cards are available, including cruciform cards (Cambridge Cruciform card and others), concertina cards (Smart system), and multiple single cards. Each of these systems has a different label and color on a different limb, fold, or sheet of card. Systems which require inappropriate categories to be torn off and discarded are best avoided as any chan ge in the patient \200\231s condition requires a replacement card. Triage is dynamic Whichever system is chosen, the card should be secured firmly to the patient and protected in a waterproof bag. If no cards are available, the triage category can be marked on the pa tient \200\231s forehead using a water- proof marker. This page intentionally left blank CHAPTER 10 Major incident management and triage 614 Trauma scoring Trauma scores are used to study the outcomes of trauma and trauma care. They are audit and research tools. They cannot be used to predict the outcome for individual pa tients. In pre-hospital care, the significance of trauma scoring is that it cannot be perfo rmed without adequate data. Good record-keeping is a pre-requisite of trauma scoring. Trauma scoring can be used to identify good quality care (patients who would be expected to die but survived) or to establish the need for improvement (patients who should have survi ved but died \200\224unexpected deaths.) Trauma scoring is an audit tool as well as a means of determin- ing the effect of financial investment in trauma care. Physiological scoring systems Trauma scores can be based on either anatomical data or physi ological data, or on both. Anatomical scores use an accurate description of a patient \200 \231s injuries and do not change. Physiological scores, However, are dynamic \200\224they c hange as the patient \200\231s condition changes. The Glasgow Coma Scale is a physiological score. It allows comparison of groups of patient with the same score. The Revised Trauma S core (RTS) is probably the most commonly used (see box). This is a coded version of the sco ring system used for the triage sort. TRAUMA SCORING1 615 Revised Trauma Score PHYSIOLOGICAL VARIABLE VALUE SCORE Respiratory rate RRc 10 \200\22329 4 >29 3 6 \200\2239 2 1 \200\2235 1 0 0 \211 90 76 \200\22389 Systolic blood pressure SBPc 4 3 50 \200\22375 2 1 \200\22349 1 0 0 13 \200\22315 4 Glasgow Coma Scale Score GCSc 9 \200\22312 3 6 \200\2238 2 4 \200\2235 1 3 0 Revised trauma score = 0.2908RRc + 0.7326SBPc + 0.9368GCSc Nearest whole number Probability of survival (%) 8 99 7 97 6 92 5 81 4 61 3 36 2 17 1 7 0 3 CHAPTER 10 Major incident management and triage 616 CRAMS (Circulation, Respiration, Abdomen, Motor, and Speech) is an alternative physiologica l scoring system which has been used in the past to attempt to differentiate major and mino r trauma. The available evid- ence would suggest that it is not sufficiently reliable to be used as a clinical tool for this purpose (see box). CRAMS Scoring system Component Score Circulation (A) Normal capillary refill and systolic BP >100mmHg 2 Prolonged capillary refill and systolic BP >85 \200\223100mmHg 1 No capillary refill 0 Respiration (B) Normal 2 Abnormal 1 Absent 0 Abdomen (C) Abdomen and thorax not tender 2 Abdomen and thorax tender 1 Abdomen rigid or flail chest, penetrating wound 0 to abdomen or thorax Motor (D) Normal 2 Responds only to pain 1 No response or decerebrate 0 Speech (E) Normal 2 Confused 1 No intelligible words 0 Total CRAMS score = A + B + C + D + E Score \211 8 major trauma Score \211 9 minor trau ma TRAUMA SCORING1 617 The Pediatric Trauma Score (PTs) is essentially a physiological score, but includes some si mple anatomical components (see box). The PTS is used as a triage tool in the USA where tra uma of different severities is taken to hospitals offering different levels of care. It is not widely used in the UK. Pediatric Trauma Score +2 +1 \200\2231 Weight (kg) >20 10 \200\22320 <10 Airway Normal Simple adjunct ET/surgical >90 50 \200\22390 <50 Systolic BP (mmHg) Conscious level Alert loss of Coma Decreased/history of consciousness Open wounds None Minor Major/penetrating Fractures None Minor Open/multiple Total score range: \200\2236 to 12 CHAPTER 10 Major incident management and triage 618 Anatomical scoring systems Anatomical scoring systems are based on a definitive assessment of the patient \200\231s injuries: they are static. The most common systems are the Abbrevi ated Injury Scale (AIS) and the Injury Severity Score (ISS). The AIS divides injuries into six body regions and scores injuries from 1 to 6 with increasing severity (injuries scoring 6 are almost invariably fatal). Scores for individual injuries are derived from a list inc luding more than 1200 injuries. The ISS is based on the AIS. The AIS is recorded for the most severe injury in the three mo st severely injured AIS regions. These scores are squared and then added together. The maxi mum score with any chance of survival is 75 (52 + 52 + 52). An AIS code of 6 in any region is auto- matically given an ISS of 75 and implies a fatal outcome. An ISS of 16 or more imp lies major trauma. Combined physiological and anatomical scoring systems The most commonly used scoring system for research purposes is the TRISS (TRauma Score-Injury Severity Score) system which combi nes an anatomical method (ISS) with a physiological system (RTS) where: Probability of survival Ps = 1/ 1+e \200\223b Where b = b0 + b1(RTS) + b2(ISS) + b3 (age co efficient) and b1 \200\223b3 are coefficients for blunt and penetrating trauma The only rel evance of the TRISS methodology in pre-hospital care is as a reminder that careful and full gathering and recording of clinical infor- mation is a key component of optimal patient ma nagement. Chapter 11 619 Chemical, biological, radiological, and nuclear (CBRN) incidents Introduction 620 Chemical incidents 622 Biological incidents 632 Nuclear and radiological i ncidents 636 CHAPTER 11 CBRN 620 Introduction CBRN incidents may occur as a result of accidental events or specific acts of terrorism. Events such as the Chernobyl nuclear incident in Russia, the Sarin gas release o n the underground system in Tokyo, and the anthrax release in the USA highlight the necessi ty for a structured multiagency and multidisciplinary response of which medical support is an essential component. Chemical incidents Chemical incidents may occur as a result of an accident involving hazard ous materials (HAZMAT) or a terrorist act. The fundamental differences being that for a HAZ MAT emergency, the chemical involved is usually immediately identifiable and, in the case o f chemical installations, the site will have been pre-surveyed with the result that there w ill be a site contingency plan already available. Accidental release may also occur as a re sult of accidents on industrial or commercial sites, in laboratories, hospitals, academic i nstitutions, materials in transit (road, rail, and sea), domestic or commercial spillage, f ire, and explosion. In contrast, a biological or radiological incident may develop from a seemingly innocuous e vent with the result that the public are unlikely to be aware, initially, that they have be en contaminated. As a result, there may be a delay in recognition of such an incident. Biological incidents Biological incidents result from the use of living organisms or inanim ate poisonous molecules isolated from them (toxins). These biological agents may take signi ficantly longer to take effect than chemicals, depending on the incubation period and mode of transmission of the agent. Recognition of incidents is usually only possible when suspic ious symptom clusters are identified or notification of a release is made. Radiological and nuclear incidents A radiological emergency results from the emission of va rious forms of radiation. Such incidents are usually the result of accidents at locations h olding radioactive materials, most obviously power stations but also including schools, hos pitals, and industrial plants. Deliberately released radioactive materials are a potential terrorist weapon as a result of the detonation of a so-called \200\230dirty bomb \200\231 or following an attack on a nuclear facility. Nuclear explosions produce direct radiation e ffects, widespread heat, and blast damage. INTRODUCTION1 621 Mode of presentation Chemical and biological incidents may present covertly. The initial pr esentation may be of a number of unrelated and unexpected patient episodes at which the amb ulance service may be the only first responders. The NATO model of \200\230STEP 123 \200 \231 may be the only indication of a covert attack. - One casualty: note signs and symptoms (normal incident) - Two casualties: note signs and symptoms \200\223 similar signs/ sympt oms \200\223 unrelated patients (suspect CBRN incident) - Three casualties: note signs and symptoms \200\223 similar signs/ symptoms \200\223 unrelated patients (strong suspicion of CBRN incident) More than three unrelated patients: showing same signs and symptoms in the absence of any other explanation indicates the presence of an external agen t (CBRN incident). In the event of a terrorist chemical incident, there is a clear risk of a secondary device or exposure designed specifically to affect or injure members of the emergency services. Clinicians likely to be involved in CBRN incidents should be familiar with local policy and be aware of relevant major incident practices including, where appropriate, the use of PPE . CHAPTER 11 CBRN 622 Chemical incidents A chemical incident may be defined as: \200\230an event leading to acut e exposure of one or more individuals to a non radioactive substance resulting in illness o r a potentially toxic threat to health \200\231. Occasionally, illness may be related to ch ronic chemical exposure, for example, carbon monoxide in a room with ineffective ventilatio n. The management of a chemical incident can be divided into two com- ponents: - Organizational Personal safety - Protective clothing - Decontamination. Clinical Substance identification - Decontamination - Triage - Immediate treatment. Scene safety Scene safety is of paramount importance during a chemical incident. It is esse ntial to ensure that it is safe to approach an incident where secon- dary contamination of responders and emergency personnel is a signifi- cant risk. The overall control at the scen e is the responsibility of the police. The fire service are responsible for containing any hazard and making the scene safe. Therefore, only when permission has been given should med ical personnel approach the scene. A rendezvous point (RVP) will often be used. The scene is divided into a hot zone, where normally only the fire ser- vise will be presen t; a warm zone, where basic assessment and decon- tamination may take place involving the f ire service and trained health service personnel wearing PPE; and the cold zone, which repr esents an area where it is no longer necessary to wear special PPE and where more detailed patient assessment and triage can take place. The hot zone is separated from the warm zone by the inner police cordon. The police outer cordon defines the external boundary of the co ld zone. Information gathering At the scene of a chemical incident it is essential to identify and g ain information about the chemical involved including its toxicity and any necessary immedi ate counter measures. At industrial installations, statu- tory regulations should ensure th at, in the event of a spillage, all aspects of scene management are part of a pre-planned e mergency procedure. In the event of a road transportation accident involving chemical vehicles, information reg arding the nature of the chemical and its handling should be available from the statutory i nformation plate displayed on the container. For railroad incidents, this information may n ot always be immediately available. Advisory systems include the HAZCHEM Action Code System, the Kemler Plate, and Transportation Emergency (TREM) Cards. This page intentionally left blank CHAPTER 11 CBRN 624 The HAZCHEM warning plate This is a series of code numbers and letters displayed on a vehic le carry- ing hazardous substances which provides information about personal protection and the fire fighting methods necessary in the event of a chemical spillage. In addition, it a dvises whether or not the chemicals can be washed into the normal drainage systems or wheth er they should be contained. Within a diamond warning sign, the United Nations number for t he chemical carried is displayed as well as a contact telephone num- ber of the manufacture r. The Kemler Plate The Kemler/ADR system is the European road transportation equivalent for h azardous road markings. The plate is in two parts, the upper displays the Kemler code for t he substance carried and the lower, the United Nations substance number. The upper numbers contain essential infor- mation in relation to the properties of the load. The first digit represents the primary hazard and subsequent two digits, the secondary hazards. If the same number is repeated, this represents an intensified hazard and, for substances which should not be brought into contact with water, the numbers are preceded by the letter \200\230x \200\231. The Transportation Emergency (TREM) Cards These are A4 size cards kept in the cab of vehicl es carrying dangerous chemicals. Each card provides details of the load, protective clothin g requirements, and the action necessary in the event of spillage or a fire. It also contai ns some information related to first aid for contaminated victims. Chemdata All fire service vehicles in the United Kingdom have access to a CHEMDATA system v ia a computer. This provides accurate information at the scene of an incident including det ails of PPE and further action in the event of a fire or spillage. Chemical incidents may be complex events and require multiagency support (for example, the Meteorological Office to give advice on wind direction in the event of a gas leak or the En vironment Agency for advice regarding water contamination). The Health Protection Agency (w ww.hpa.org.uk) is available 24hrs a day for support and advice on such issues as: - PPE - D econtamination and evacuation - Toxicological and epidemiological impact on public health - Antidotes and medical treatment - Public health impact of industrial sites - Health effect s from chemicals in the environment. CHEMICAL INCIDENTS1 625 (a) Coded information for the emergency services United Nations number for the substance 2WE 2447 (0123) 45678 Telephone number for further information Nature of potential danger Issue No 1 Hazchem Scale (b) Hazchem UN No FOR FIRE OR SPILLAGE JETS 1 2 FOG FOAM 3 4 DRY AGENT P R S S T T W X Y Y V FULL BA BA for FIRE only BA BA for FIRE only V DILUTE V FULL BA BA for FIRE only BA BA for FIRE only V CONTAIN Z Z E CONSIDER EVACUATION Fig. 11.1 The HAZCHEM Action Code System: (a) the HAZCHEM hazard warning plate; (b) the HAZ CHEM code system aide memoire card (front); (c) back. CHAPTER 11 CBRN 626 Notes for Guidance (c) FOG In the absence of fog equipment a fine spray may be used. DRY AGENT Water must not be allowed to come into contact with the substance at risk. V Can be violently or even explosively reactive. FULL Full body protective clothing with BA. BA Breathing apparatus plus protective gloves. DILUTE May be washed to drain with large quantities of water. CONTAIN Prevent, by any means available, spillage from entering drains or water course. Fig. 11.1 Contd. In particular, advice is available to the medical profession on the best way to manage pati ents who have been exposed to poisons. This is given through the National Poisons Informati on Services (NPIS) which are based in Oxfordshire, Birmingham, Cardiff, Newcastle, and Lond on. Clinical management Key management tasks in relation to the medical support provided at an incident: - Establish details of the exact location, type of incident, and hazards (preferably before approaching the incident). - Approach from upwind and from a safe distan ce. - Remain at a rendezvous point (if given) and advance to the scene only when instructed that it is safe to do so. Report to the ambulance incident command center (if already set up) on arrival or the individual acting as the ambulance commander. Only wear PPE if you have been trained to do so. - Establish the casualty clearing station at a safe distance upwind and uphill from the incident. Be mindful of the risk of the spread of contamination throughout all the stages of casualty contact. CHEMICAL INCIDENTS1 627 Be aware that the risks are dynamic (for example, that the wind may change); it is essentia l to be in contact with the ambulance incident officer to minimize risk. Do not allow clinical care to take place in the hot zone. - Establish resuscitation based o n triage assessment where necessary during decontamination in the warm zone. Consider the possibility of secondary trauma as well as chemical contamination. DO NOT approach an incident unless you are SURE it is safe to do so. Triage There are three main categories of clinically contaminated patients: - P1 \200\224re suscitation required during decontamination in a stretcher facility. P2 \200\224treatment may be delayed until after decontamination in a stretcher facility. P3 \200\224minor injuries; patients may walk unaided to a decontamination facility. Following decontamination, normal triage priorities can be used (see p.602). 32 1274 Fig. 11.2 The Kemler hazard warning plate. CHAPTER 11 CBRN 628 Decontamination Decontamination should ideally take place as near to the source of the chem ical exposure as possible, providing that the patient and the scene are safe. At the scene of an incident, decontamination will take place in the warm zone by personnel familiar with the appropriate PPE. It is essential that they have been trained and have experience of wo rking within this environment. Decontamination of casualties is now officially an ambulance service responsibility, although both the fire service and ambulance service are likely to be involved in any significant incident. Patients may present to emergency departments, risking the spread of contamination. For thi s reason, selected emergency department person- nel are trained in decontamination techniqu es. A&E departments must always be warned of the impending arrival of contaminated or potential ly contaminated patients. On arrival at hospital with contaminated patients, instructions from A&E staff MUST be foll owed. DO NOT enter the department until instructed to do so. Decontamination is achieved by removing decontaminated clothing and washing the patient tho roughly with water. Under certain circumstances detergent is added. Clothing should be bagg ed securely for disposal or retained if necessary for forensic purposes. If indicated, emer gency life- saving procedures may be undertaken before or during decontamination in the war m zone. Hypothermia is a significant risk from the decontami- nation process. Appropriate c lothing is provided post decontamination. Resuscitation Resuscitation should follow the normal ABCDE priorities. However, this may ne ed to be undertaken wearing appropriate PPE. If such equipment is not available, or staff a re not experienced in its use, resuscitation must not be attempted. It must be remembered t hat there is a risk of con- tamination via the skin or mucosal surfaces. Manual ventilation equipment should be fitted with absorbent canisters if they are to be used in a toxic envi ronment. Should it be necessary to use a defibrillator, both the patient \200\231s chest an d the emergency responder should be as dry as possible to avoid electrical injury. Expert a dvice should be sought prior to deliver- ing defibrillation in an explosive or combustible environment. CHEMICAL INCIDENTS1 629 In the event of a toxicological emergency either contact the National Poisons Advisory Serv ice on 0870 600 6266 or use TOXBASE on www. hpa.org.uk/chemicals/toxbase.htm Note: Prior registration is necessary before toxbase can be used. CHAPTER 11 CBRN 630 Treatment It is essential to move the patient as soon as possible from any ongoing exposure to the chemical or toxin. Removal of contaminated clothing constitutes 70% of the decontam ination process. Attention to any abnormalities found in the primary survey, the correction of hypoglycaemia if present, and the management of any associated medical conditions const itute the basis for treatment. From the point of view of the chemical exposure, treatment i s usually supportive, initially. Intervention (based on expert advice from the HPA or the N PIS) using drugs or specific chemical antidotes may be possible from dedicated pods which w ill be trans- ported to the scene by the ambulance service. Transfer It is important to ensure that vehicles transporting casualties to hospital do not enter a contaminated area. In addition, those vehicles transferring patients who have been contaminated will require equipment and vehicular decontamination afterwards. It is essent ial to avoid secondary contamination. Documentation Contemporary documentation is desirable, though difficult at a chemical incid ent because of the use of PPE. When and where possible, documen- tation must be undertaken but should not risk secondary contamination. The first opportunity for formal documentation may be when the patient has been decontaminated and reaches the cold zone. Debrief In common with all major incidents, there should be a \200\230hot debrief \200\231 when the incident ends which should identify problems for future consideration as well as allaying concerns with regard to the risks to health care workers. A planned emergency services/interagency debriefing will permit more attention to detail and allow established plans to be modified. Individual chemicals Carbon monoxide \200\224see p.421 Chlorine \200\224see p.423 CS gas an d related agents \200\224see p.425 Cyanide \200\224see p.426 Organophosphate insecticides \200\224see p.442 Paraquat \200\224see p.444 This page intentionally left blank CHAPTER 11 CBRN 632 Biological incidents A biological agent (BA) is a micro-organism or a toxin derived from it which causes disease in man. The toxin may be derived from living plants, animals, or micr o-organisms. Some toxins are produced or altered by chemical means. Toxins are unable to re produce themselves and are normally of a simpler biochemical composition than a biological agent. Historically, biological incidents may be natural or intentional. Inten- tionally, biologic al agents have been used in warfare, including World War Two, during the Iran/Iraq conflict , and, more recently, the postal delivery of anthrax spores in the United States in 2001. Features of biological weapons - Have the potential to effect large numbers of people - Hav e the potential for widespread geographical exposure - Often have a simple means of distrib ution - Are initially untraceable - Are difficult to detect and difficult to effectively pr otect against. Characteristics of biological agents Pathogenicity This is the capability of the biological agent to cause disease. Infectivity This is the amount of agent required to cause disease. Pathogens with high infectivity produce disease with a smaller number of organisms compared to those of low infectivity which require larger numbers. Infectivity does not determine t he speed of onset or the severity of the illness. Virulence This reflects the relative severity of diseases produced by biological agents whi ch can vary between different organisms and strains of the same organism. Toxicity Toxicity reflects the relative severity of the illness produced by the toxin. It i s dose dependant. Incubation period Providing there are sufficient number of micro-organisms to initiate infe ction, the infectious agent then multiplies to produce disease. The time between exposure a nd the appearance of symptoms is the incubation period. In the case of toxins, sufficient quantities must penetrate the body to produce intoxicatio n. The time between exposure and clinical features is known as the latent period. BIOLOGICAL INCIDENTS1 633 Biological threats Class A agents (most dangerous due to easy dissemination, high mortality ) Bacteria Viruses Toxins Smallpox Ebola* Botulinum Anthrax Marburg* Some mycotoxins Plague Arena viruses Botulism Lassa fever Tularaemia Junin and related viruses* Dengue Class B agents (moderate ease of dissemination, moderate mortality and morbidity) Bacteria Viruses Toxins Q fever Venezuelan EE** Ricin Brucellosis Eastern EE** Epsilon toxin Glanders, melioidosis Western EE** Staph. Enterotoxin B Salmonella (WC) Other alphaviruses Shigella dysenteria (WC) E.coli O157:H7 (WC) Cryptosporidium parvum (WC) Class C agents (low to moderate threat) Multidrug resistant TB Nipah virus Hantaviruses Tickborne haemorrhagic fever encephalitis viruses Yellow fever Haemorrhagic fever viruses Equine encephalitis From C. perfringens WC=potential water contamination agents CHAPTER 11 CBRN 634 Transmissibility Transmissibility is the potential for a BA to be transmitted from one pers on to another directly or through a vector. Those agents transmitted easily from one person to another constitute a major concern. Lethality The lethality or fatality rate is an expr ession of the number of deaths in relation to the number of casualties. Stability The stabi lity of a BA depends on many factors including temperature, humidity, and exposure to sunli ght. Infectious dose This is the dose of an organism needed to infect a person. Due to indi vidual variation, this is expressed as the median dose given \200\224the dose needed to inf ect 50% of those exposed. Lethal dose This is the dose of a BA needed to cause death. Classification An understanding of the characteristics of a BA is essential for identificat ion, prophylaxis, and treatment. BAs used as weapons can be grouped into: - Bacteria - Viru ses - Toxins. (See box on p.633.) Dissemination Dissemination describes the process of dispersal of BAs or toxins. They are m ost commonly dispersed covertly and by aerosol. Routes of entry are similar to naturally oc curring diseases, including percutaneous, inhalation, and ingestion (contamination of food and water). Recognition It is quite likely that a biological warfare attack will be covert and late at night or in the early morning to avoid inactivation of an aerosol driven BA by ultraviolet light. Activation within a closed space may have a more profound and obvious effect. It may be difficult to differentiate illness produced by a BA from an endemic disease. Diseases o ccurring outside their normal geographical location may be more easily identified as suspi- cious. Alerting features include: - Large numbers of casualties occurring over a short per iod of time - Signs of illness or death in the animal population. Casualty management Patients may be a victim of the BA or a traumatic injury. Attempts shou ld be made to minimize cross-contamination without compromising effec- tive clinical care. ABC management of life-threatening injuries should take priority over decontamination if po ssible. Clinical care should be delivered by practi- tioners wearing appropriate PPE. BIOLOGICAL INCIDENTS1 635 Treatment should include general supportive measures: maintenance of adequate respiration, intravenous access, and analgesia, as well as the management of any co-existing injuries an d pre-morbid conditions. Antibiotic therapy, antiviral therapy, and antitoxin therapy shoul d be given as ap- propriate. Attempts should be made to separate contaminated victims from non-affected patients. Medical personnel should be familiar with the local response plan for handling biological emergencies. All suspected biological agent cases should be evacuated to a specialist center wherever po ssible. Anthrax Causative organism Bacillus anthracis Incubation period 1 to 6 days; may be longer Symptoms - Fever, non-productive cough, malaise, fatigue, chest discomfort, sore throat May be followed by a brief period of improvement - Followed by sudden deterioration with se vere respiratory distress, sweating, stridor, cyanosis, and shock Death 24 to 36 hours after onset of severe symptoms. Signs - Pleural effusion, chest wall oedema, meningitis (inhalational anthrax) - Papule les ion, becoming vesicular with a black scab (eschar); local and systemic infection (cutaneous anthrax) Tonsillar ulceration (oropharyngeal anthrax). Immediate management - Wear appropriate standard PPE (if there is a risk of anthrax spore contamination, breathing apparatus will be required) - Decontaminate patient with copious s oap and water - Triple bag and seal patient \200\231s clothing - Transfer urgently to hospi tal \200\224warn them in advance; DO NOT enter the hospital until advised to do so Ensure appropriate decontamination (hypochlorite is appropriate) - If confident about diagn osis or clinically concerned, give intravenous benzyl penicillin Seek advice. Note Inhalational anthrax is not infectious; skin lesions and spore-contaminat ed clothing are. CHAPTER 11 CBRN 636 Nuclear and radiological incidents Nuclear incidents (i.e. detonations or releases of radio active material) are, fortunately, much rarer than radiation incidents (release of ionizing radiation). Radioactive materials occur widely \200\224for example, in industry, medicine, and waste from the nuclear power industry. Associated with these activities is the frequen t movement of radioactive materials on road and rail systems. The Health Protection Agency provides advice and support in the event of a radiation incide nt through the National Radiological Protection Board (NRPB) who in turn advise both the go vernment and the local emergency centers involved with the incident. This involves specifyi ng and providing guidance on emergency reference levels (ERLs) including ERLs requiring urg ent evacuation, shelter, and administration of stable iodine as well as advice on the contr ol of food and drinking water. In addition, the NRPB provides information on recovery metho ds post incident. Where the potential for an incident exists, there are statutory obligations to ensure suita ble contingency plans to protect workers and the public. In the event of an unforeseen inci dent, the NAIR arrangements can be implemented. NAIR may provide assistance to local emerge ncy plans and are activated by the police when they feel that there is a need for radio- lo gical assistance. Other emergency services, (for example, the fire service, British Transpo rtation Police, and the airport and docks police) may also initiate NAIR assistance. The NRPB co-ordinates the NAIR arrangements. Monitoring NAIR provides prompt assistance to the police and emergency services where no ra diation expert is available. Assistance is provided in two stages. - Stage 1: a radiation e xpert, with the aid of simple monitoring equipment, can determine whether a hazard exists and can advise the police accordingly. If required, the police can obtain stage 2 assistance. Stage 2: comprises more sophisticated resources and a team, usually provided by a major nuclear establishment and consisting of up to four persons who can resp ond urgently with monitoring, decontamination equipment, and special clothing. In addition, the NRPB will collate and interpret data from other agencies involved. Action to be taken in the event of an apparent radioactivity emergency: - Police will deter mine whether a pre-existing plan exists. In the event of there being no plan, NAIR assistance will be obtained. Stage 1 respondent will determine whether a stage 2 response is required immediately. A major spillage will require a stage 2 response immediately. NUCLEAR AND RADIOLOGICAL INCIDENTS1 637