Biological and Chemical Warfare

1
Biological and Chemical Warfare
2
Anesthesiologists role

• Very difficult to anticipate all the ways in
  which anesthesiologists may be asked to assist in
  managing mass casualty situations
• could be involved with triage in ER, operating
  room, ICU
• Since the Sept. 11th attacks and subsequent
  anthrax attacks, JCAHO published guidelines to
  help hospitals and the community deal with
  catastrophic events that could inundate the
  healthcare system
• Being familiar with your own hospital protocols
  and procedures will help you anticipate the role
  you play in mass casualty situations

3
Biological Terrorism

• Ideal Biologic agent is one that has the greatest
  potential for adverse public health impact,
  generating mass casualties with potential for
  easy large-scale dissemination that could cause
  mass hysteria and civil disruption
• Three categories of biological weapons, Category
  A being most contagious and fitting the
  description of a relatively ideal biologic agent
• Category A Includes Anthrax, Smallpox, Plague,
  Tularemia, Viral Hemorrhagic fevers, and various
  encephalitic viruses (Ebola, Lassa,
  Margurg,Argentine)
• Category B includes Q fever, Cholera, Glanders,
  Salmonell, Shigella, and various biologic toxins
• Category C includes various encephalitic viruses

4
Biological agents

• Anthrax (appeal of anthrax is that it can be
  easily aerosolized)
• Three types (Cutaneous, inhalation, and GI) most
  cases being cutaneous (95)
• Normally, if anthrax spores are inhaled, they
  clump in the nasal pharynx, to be inhaled to the
  terminal bronchioles and alveoli the spores must
  be finely ground
• One of the letters that was mailed in the anthrax
  attacks of 2001 contained 2g of weapons grade
  anthrax, enough material to infect 50 million
  individuals
• inhalational manifests as in influenza like
  disease with fever, myalgias, malaise,
  nonproductive cough with or w/o chest pain, may
  progress to necrotizing hemorragic
  mediastinitis, MOF, and death in 24-36 hours
• non specific physical findings ,you may see a
  widened mediastinum on CXR
• Treatment is doxycycline or ciprofloxacin
• an attenuated michigan vaccine is available

5
Anthrax

• Cutaneous anthrax showing the black eschar

6
Biological Agents

• Plague(bubonic and pneumonic)
• Bubonic plague has 2-6 day incubation period
• Transmitted by flea vectors from rodent
  reservoirs, by animal to human droplet infection,
  or human to human droplet infection
• sudden onset of fever, chills, weakness, and
  headache. If untreated, eventually develop septic
  shock with cyanosis and gangrene in peripheral
  tissues
• Patient with pneumonic plague should be managed
  as having drug resistant tuberculosis (fatal
  unless treated within 24 hours of symptoms)
• Treatment is streptomycin, or chloramphenicol and
  tetracycline
• Greer vaccine available, but efficacy thought to
  be poor

7
Biological Agents

• Smallpox (declared to be eradicated by WHO in
  1980)
• Routine vaccination was stopped in the United
  states in 1972
• 40-80 exposed will develop the disease
• appox 30 mortality rate if unvaccinated and 50
  in communities with no native immunity
• Usually see a prodrome of 7-17 days, with upper
  and lower resp tract infections with thoracic
  lymph nodes involved, following malaise, fever,
  headache, backache, rigors, and delirium. Over
  the next few days an erythematous rash develops
  over the face, hands, and forearms. Mucous
  membranes produce infectious secretions and rash
  becomes maculopapular as it spreads over the legs
  and and trunk
• Treatment is Cidofovir, a DNA polymerase
  inhibitor used to treat CMV in AIDS patients.
  Ribavirin and Sandoglobulin may also be used.

8
Smallpox

• Small Pox on the abdomen and face of a child

9
Biological Agents

• Botulinum Toxin causes a neuroparalytic disease,
  not contagious, it is a gram positive spore,
  obligate anaerobe widely distributed in nature
  and soil, marine, and agrculture products.
• Most potent poison known to humans, US, former
  soviet union, Iraq, Iran, Syria, North Korea all
  produce in large quantities (Irag admitted to
  having more than 19000 liters of the toxin
  loaded on weapons after the first Gulf War)
  enough to kill the worlds population three times
  over.
• Humans ingest it without effects. It is the toxin
  that produces the effects
• Once ingested or inhaled, toxins bind to the
  cholinergic receptor and block the release of
  acetylcholine causing progressive weakness,
  flaccid paralysis beginning in the extremities
  and moving onto respiratory muscles, also d/c in
  salivation, ileus, and urinary retention
• typical incubation period is 12-36 hrs
• treatment is a trivalent antitoxin, w/o
  antitoxin, it takes patients 2-8 weeks to recover
• mortality rate is 5-10

10
Hemorrhagic Fevers

• Various Viruses (Lassa Fever, hanta virus, Ebola,
  Marburg) there are at least 18
• viruses replicate in lymphoid cells, incubation
  period is anywhere from 2-18 days depending on
  the size of the inoculum
• Typically see fever, myalgia, capillary leak,
  pulm edema, DIC, thrombocytopenia
• Both the US and former soviet union have
  experimented with and weaponized several of these
  viruses
• Treatment is mainly supportive
• No specific antiviral treatments but anecdotal
  reports of ribavirin, interferon, and hyperimmune
  globulin as being protective

11
(No Transcript)
12
Chemical Agents

• Potential Chemical Weapons
• Nerve agents include GA(tabun),GB(Sarin),GD(soman)
  , GF, and VX
• Pulmonary Agents include Chlorine and phosgene
• Blood Agents include (AC or hydrogen cyanide and
  cyanogen chloride or CK)
• Vesicants Include H and HD (sulfur mustard,
  nitrogen, mustard and lewisite)

13
Nerve Agents

• Ones we are familiar with are neostigmine,
  physostigmine, pyridostigmine
• Nerve agents were first mass produced in Germany
  prior to WWII
• In increasing potency are GA,GB,GD,GF,and VX
• They are clear, colorless liquids that vaporize
  at room temp and penetrate skin,clothing, or the
  epithelium of lung or GI tract
• inhibit acetylcholinesterase, the overall
  unopposed parasympathetic activity leads to the
  common pnemonic DUMBELS(Diarrhea,urination,
  miosis, bronchorrhea, bronchoconstriction,
  emesis, lacrimation, and salivation
• At preganglionic nicotinic receptor sites, you
  see tachycardia and hypertension, but muscarinic
  activation causes bradycardia the net effect on
  the cardiovascular system is difficult to
  anticipate
• Activation of the nicotinic receptor on the
  neuromuscular junction can cause fasciculatoins,
  twitching, fatigue, and flacid paralysis
• Treatment depends on the degree of exposure,but
  Atropine and 2-PAM(pyroidostigmine) or
  pralidoxime chloride are the usual treatment
• The US military travels with automatic injectors
  of 2mg of atropine and 600 mg of pyridostigmine

14
Pulmonary Agents

• First chemical agents to be used in warfare
  during WWI by the Germans against the allies
• Four primary pulmonary agents (Chloropicrin,chlori
  ne, phosgene, and diphosgene
• Phosgene the prototypical agent, most deadly of
  the pulm agents
• a colorless gas that has the odor of recently cut
  hay at 22-28 degrees celsius and normal pressure
  conditions
• Highly lipid soluble, penetrating pulm epithelium
  and alveoli, and reacts with water to form HCl
  and CO2, causing capillary leak and acute lung
  injury
• Treatment is supportive and gas masks provide the
  best protection

15
Blood Agents

• These include Hydrogen Cyanide(AC), hydrocyanic
  Acid, cyanogen chloride, and arsine
• Difficult to use as a mass casualty weapon
  because of volatility (boiling point is 25.7
  degrees celsius
• In open areas not effective, but in closed spaces
  can be more effective
• AC interferes with cytochrome oxidase and
  cellular respiration leading to metabolic
  acidosis and cellular hypoxemia
• Depending on the exposure symptoms range from
  headaches, dyspnea, palpitations to collapse
  followed in 1-2 minutes by convulsions and
  cardiac arrest
• Treatment is with sodium thiosulfate. Cyanide
  ions are normally metablized by the body by the
  rhodanase enzyme in the liver, which is a sulfur
  requiring step that leads to the bioformation of
  methemoglobin. Insufficient sulfur doesnt allow
  the enzyme to operate efficiently, thus give
  sodium thiosulfate

16
Vesicants

• Include Sodium mustard, nitrogen mustard,
  phosgene oxime, and lewisite
• Also known as blister agentsbecause of the
  burns and blisters caused by contact with skin,
  but can cause pulmonary damage if inhaled,
  readily penetrates clothing and damages all
  mucous membranes
• They are colorless and almost odorless, if temp
  is high enough, produce rotten onion or mustard
  odor
• Highly reactive chemical structure that readily
  binds to nucleic acids, proteins, and nucleotides
• A nuclear-biological-chemical protective suit and
  gas mask provide the best protection against
  sulfur mustard

17
(No Transcript)
18
Question

• Which of the following tissues are most sensitive
  to the effects of ionizing radiation?
• A. LymphoidgtGIgtreproductivegtdermalgtnervous system
• B. DermalgtGIgtLymphoidgtreproductivegtnervous system
• C.LymphoidgtreproductivegtGIgtnervous systemgtdermal
• D. LymphoidgtdermalgtreproductivegtGIgtnervous system
• E. Nervous systemgtreproductivegtlymphoidgtdermalgtGI

19
Answer

• A. Tissue sensitivity to the effects of ionizing
  radiation varies based on cellular turnover rate.
  In general, tissue with the highest turnover rate
  is most affected by exposure to ionizing
  radiation. From greatest to least, sensitivity
  of human tissue to ionizing radiation is as
  follows LymphoidgtGIgtreproductivegtdermalgtnervous
  system

20
Question

• Which of the following statements regarding the
  National Pharmaceutical Stockpile is FALSE?
• A. It includes airway maintenance supplies
• B. It was established by the centers for Disease
  Control and Prevention
• C. It is organized in two phases, the first phase
  involving distribution and prepackaged push
  packages with critical medical supplies and a
  2nd phase in which additional resources can be
  quickly mobilized if necessary
• D. It includes certain antibiotics and chemical
  antidotes
• E. It is controlled by the Federal Emergency
  Management Agency (FEMA).

21
Answer

• The National Pharmaceutical Stockpile was
  established by the CDC to ensure the rapid
  availability of medical supplies to facilitate
  emergency response in the event of a national
  disaster. The stockpile contains specific
  antidotes, chemical antidotes, life support
  medications, intravenous administration supplies,
  and airway maintence supplies, as well as other
  surgical and medical items. There are two phases
  to this program. The First is the provision of 8
  separate, yet identical, prepacked caches of
  medical materials called 12-hour push packages
  that are deployed around the U.S. The second
  involves mobilizing specific additional supplies
  from Vendor Management inventories capable of
  arriving w/in 24 to 36 hrs of the initial
  request. FEMA does not have authority over the
  National Pharmaceutical Stockpile.

22
Question

• Specific therapy for high dose exposure to
  cyanide includes
• A. Sodium Thiosulfate
• B. Arsine
• C. Pralidoxime Chloride
• D. Hyperbaric oxygen
• E. Pyridostigmine

23
Answer

• Cyanide ions are normally metabolized by the
  rhodanese liver enzyme in a sulfur requiring step
  that leads to the formation of methemoglobin. In
  the setting of cyanide poisoning, sulfur stores
  are depleted, leading to enzymatic dysfunction.
  Treatment of cyanide poisoning therefore includes
  administration of sodium thiosulfate as a sulfor
  donor to regenerate enzymatic metabolism of
  cyanide ions. In the meantime, the patient may
  require tracheal intubation and ventilation,
  NaHCO3 to treat metabolic acidosis, and inotropes
  and vasopressors for hemodynamic support. Arsine
  is one of the cyanogens that can cause cyanide
  toxicity, along with hydrogen cyanide,
  hydrocyanic acid, and cyanogen chloride.
  Hyperbaric o2 may play a role in the management
  of carbon monoxide poisoning but is not indicated
  for cyanide poisoning. Pralidoxime chloride
  reactivates acetycholinesterase and is used to
  counteract the muscarinic and nicotinic stimulant
  effects of nerve agents that inhibit
  acetylcholinesterase. Pyridostigmine is sometimes
  given prophylactically in situations in which
  exposure to nerve agent is anticipated b/c it
  binds to acetylcholinesterase and thereby
  protects it and allows for spontaneous enzyme
  regeneration.

24
Question
25
Imagine doing anesthesia in this thing