Regarding health and safety issues at a disaster site, which ONE of the following statements is TRUE?
Answer: A: The 1-2-3 of safety refers to the order of priority in considering safety on site:
This prevents rescuers from becoming injured, and therefore adding to casualty load while reducing caring staff.
In a suspected chemical, biological or radio-nuclear exposure, the area immediately around the contamination is referred to as the ‘hot zone’. Security is set up to control access to this area via a specific point allowing only staff equipped with PPE. Surrounding this is the warm zone in which decontamination of casualties and staff is performed under the supervision of a decontamination officer. The cold zone in turn surrounds this. The size of these zones will depend on the scale and nature of the potential threat, and may alter by subsequent circumstances (e.g. change in wind or rain). These zones are controlled by the police.
Noxious agents have four routes of access into the body: inhalation, skin, eye and ingestion. PPE and decontamination processes must take this into consideration. Decontamination should involve cutting off patients’ clothing rather than lifting it over their face and airway, then applying a rinse-wipe-rinse technique using dilute detergent solution.
Patients requiring decontamination should not be transferred into the cold zone because of the risk they then pose to healthcare staff and the public. PPE places significant restrictions on the senses, and cannot be worn while driving or caring for a patient in an ambulance.
Reference:
Regarding biological emergencies, which ONE of the following statements is TRUE?
Answer: C Smallpox virus spreads by person-to-person droplet transmission. Infection via pharynx results in widespread centripetal vesicular skin rash, high fever and severe abdominal pain. Diagnosis is made by electron microscopy findings in association with clinical features. The discovery of a single suspected case should be treated as an international health emergency.
Anthrax is a naturally occurring aerobic, grampositive bacillus which can cause respiratory, cutaneous or gastrointestinal infections. Mortality is high, due to bacterial toxins provoking a secondary lymphadenitis, causing haemorrhagic necrosis of exposed tissue. Person-to-person transmission has not been reported. While most strains are penicillin sensitive, the possibility of deliberately engineered attack has led to a recommendation of prolonged combination chemotherapy, primarily including ciprofloxacin.
Pneumonic plague is a rapidly progressive, frequently fatal febrile illness, considered to be the most likely form of a deliberate exposure. It carries a high risk of respiratory droplet transmission, and is rapidly fatal if not treated within 24 hours with double-agent chemotherapy, including streptomycin or gentamicin.
Botulinus toxin blocks peripheral cholinergic synapses, resulting in a flaccid paralysis that characteristically first presents in the bulbar muscles. Treatment is largely supportive, including ventilation and parenteral nutrition.
Regarding potential chemical exposures, which ONE of the following statements is TRUE?
Answer: A: Most modern chemical warfare agents (e.g. sarin) are organophosphates. Toxicity can be acute, intermediate, or delayed, depending on the agent used. They cause actions at the autonomic ganglia. The toxidrome can be prompted by the following mnemonic.
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Respiratory paralysis may require supportive ventilation for days. Atropine is first-line treatment for organophosphate toxicity, reversing non-neuromuscular and central nervous system (CNS) manifestations including bradycardia. However, the toxidrome of sarin, while an organophosphate, is not responsive to atropine. Pralidoxime is most effective early in post-sarin exposure.
In treating cyanide exposure, which causes toxicity by inhibiting cellular respiration, the drug of choice is intravenous hydroxycobalamin, which forms a stable compound that is then renally excreted. Mustard gas is a vesicant agent, liquid at room temperature, which attacks the skin and mucosal surfaces and poses an ongoing threat to treating staff. Death is most commonly due to pulmonary destruction. However, the toxic agent is not present in blister fluid.
References:
Regarding a patient experiencing a significant radiation exposure, which ONE of the following statements is TRUE?
Answer: D: In the event of a nuclear accident, radioactive iodine might be released into the environment. Potassium iodate tablets block the uptake of radioactive iodine by the thyroid gland, therefore reducing the risk of developing thyroid cancer.
Irradiated patients are not radioactive, and so do not pose a threat to staff. Patients exposed to particulate radioactive material – such as following an explosion – may still have radioactive material on their person, and so should be considered as requiring decontamination until declared clear by a radiation safety officer. Haemopoetic syndrome – due to bone marrow suppression – displays developing symptoms of bleeding, depressed white cell count (WCC) resulting in impaired immune response and fatigue by 3 weeks post exposure. Treatment is supportive.
Gastrointestinal symptoms of vomiting, bloody diarrhoea and ileus denote an exposure of >2–10 Gy, and result in 50% mortality due to renal, hepatic and pulmonary injuries.
In applying a triage sieve to the following patients in a mass casualty incident, which ONE of the following statements is TRUE?
Answer: C: In the initial triage sieve of mass casualties, the priority of healthcare is shifted from ‘the best care for every patient’ to ‘do the greatest good for the greatest number’. The process is to determine which patients should be taken to different treatment areas, and in which order.
All patients will then be reassessed at the casualty clearing station using the triage sort, a more detailed physiology-based assessment.
Triage exercises may be used to practise the triage sieve or sort processes used in a disaster situation. This can be done as a paper exercise for individuals, or with a group allowing discussion of decisions and processes.
Table-top exercises are run for small groups, and may be useful for assessing or rehearsing particular aspects of a plan such as identifying areas of a hospital or site for strategic planning. This works best when the group comprises individuals who represent different groups or specialties, and are useful in demonstrating command, control and communication processes.
A large multi-agency exercise with live casualties provides a realistic way of testing out-of-hospital responses, and the casualties used can be progressed through to be used in an in-hospital exercise. However, it is difficult to perform this without disrupting hospital function, and conducting the process can be expensive, complex, and requires much forward planning and coordination.
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