Emergency Medicine/Dysbarism

Topics Covered

• Radiation Background ==
• “Dirty Bomb” ==
• Radioactive Waste / Nuclear Reactors ==
  • Yucca Mountain ===

Basics of Radiation- Irradiation

• Irradiation is exposure to penetrating radiation ==
  • External irradiation does not make a person radioactive. ===
  • External irradiation can damage tissue through direct or indirect means (generation of free radicals and H2O2 from ionization of water) ===

Basics of Radiation- Contamination

• Contamination occurs when material that contains radioactive atoms is deposited on skin, clothing, body cavities, wounds. May also damage tissue, but much more slowly than direct irradiation. ==
• Person contaminated with radioactive materials will be irradiated until the source of radiation (the radioactive material) is removed ==

Basics of Radiation

• Ionizing radiation is produced by unstable atoms (isotopes) which have an excess of energy or mass. ==
• Atoms give off, or emit, the excess energy or mass as radiation which collide with adjacent molecules and ionize (knock off electrons) ==
  • electromagnetic ( gamma or x-rays) ===
  • particulate (i.e., mass given off with the energy of motion - beta and alpha radiation). ===

4 types of ionizing radiation

• Alpha- little penetration, easily stopped by skin and clothes, dangerous if ingested or inhaled. 20x more damaging than equivalent dose of beta or gamma. ==
• Beta- light penetration, may cause red “burn” on skin. ==
• Gamma- deep penetration, like x-rays. ==
• Neutrons- particles that also penetrate deeply and cause extensive damage. Seen only in nuclear bombs. ==
• All types of radiation cause damage to DNA of cells. Most vulnerable tissues are heme, GI and reproductive systems. ==

Biological Effects of Radiation

• Stochastic- effects that are also seen in unexposed individuals, but are increased in frequency with radiation exposure (trigger effect). Not all individuals exposed will get effect. Severity is independent of dose. ==
  • Examples include cancer, mental retardation in exposed fetus, genetic damage. ===

Biological Effects of Radiation

• Non-stochastic effects- threshold dose, predictable causal relationship with dose related severity in all individuals exposed. ==
  • Sterility, skin burns, cataracts, hemopoietic damage, GI and CNS damage. ===

Radiation Physics for Dummies

• Absorbed dose = energy/mass=joule/kg ==
• 1 Roentgen=1 rad ==
• 100 rad= 1Grey(Gy). ==
• Dose equivalent=energy/mass x (strength of type of radiation). Alpha is 20x. ==
• 1 rad of gamma is 1 rem ==
• BUT ==
• 1 rad of alpha is 20 rem ==
• 100 rem = 1 Seivert (Sv) ==

Radiation Physics for Dummies

• Natural radioactivity - 40 mrem/year. ==
• Air travel NYC-London- 4 mrem ==
• CXR- 10 mrem ==
• National Council of Radiation Protection ==
  • 5 rem/yr (50 mSv) =annual exposure limit of radiation workers ===
  • 0.5 rem (500 mrem or 5 mSv) = max annual exposure to layperson = 50 CXR. ===

Radiation Physics for Dummies

• 50 rem is max single dose recommended for a first responder acting in a life saving situation ==
  • No risk of Acute Radiation Sickness ===
  • 1-4% estimated increase in Ca risk. ===
• In this case, rem = rad, since workers in this situation will be wearing PPE, so gamma is only radiation that will penetrate. ==

Biological Effects of Radiation

• Sterility- 30 rads in men, 300 rads in women. More exposure leads to longer effect. Usually temporary ==
• 100 rads = N/V ==
• 200 rads = Cataracts, Hemopoietic syndrome ==
• 300 = skin erythema ==
• 400 rads = usually fatal ARS due to heme depression. ==
• 1,000 rads = GI syndrome → FATAL. ==
• 2,000 rads = CNS syndrome → FATAL ==

What is a “Dirty Bomb”?

• A conventional explosive packaged with radioactive material that scatters when the bomb goes off. ==
• Could be a small device, or as big as a truck bomb ==

How does a Dirty Bomb do harm?

• Initial blast of the conventional explosive ==
• Airborne radiation and contamination ==

Only nuclear experts can make one, right?

• Nope, requires not much more expertise than it takes to make a conventional bomb ==

So why aren’t we all dead?

• The hard part is acquiring the radioactive material, not building the bomb. ==
• There are reports that suggest organizations, such as Osama bin Laden’s al Qaeda, probably have radioactive contaminants such as strontium 90 and cesium 137, which could be used to make a dirty bomb, and have succeeded in manufacturing a small dirty bomb ==

Why else aren’t we all dead?

• A dirty bomb is not a nuclear weapon ==
• (nuclear weapons involve a complex nuclear-fission reaction and are thousands of times more devastating) ==

So do we have to worry?

• Yes, dirty bombs are WMD’s but… ==
• More for their capacity to cause terror and disruption than inflicting heavy casualties. ==
  • Panic over radioactivity ===
  • Evacuation measures ===
  • Area struck would be off-limits for at least several months—possibly years—for cleanup efforts ===

Acme Radioactive Materials, on sale for 3 payments of $9.99?

• Radioactive materials for military, industrial, or medical applications: e.g. weapons-grade plutonium or uranium, freshly spent nuclear fuel ==
  • the most deadly ===
  • the most difficult to obtain ===
  • Medical supplies such as radium or certain cesium isotopes used in cancer treatments could be used ===
• less dangerous
• A measuring cup’s worth of radioactive material would be needed, but such small amounts would be unlikely to cause severe harm, especially if over a wide area.

Dirty Bomb- Summary

• Explosion and trauma, moderate dispersal of radioactive debris, imbedded fragments, very little irradiation ==

Yucca Mountain

• http://www.ocrwm.doe.gov ==

Location

• Nye County, Nevada, ~100 miles NW of Las Vegas ==
• Remote desert on federally protected land ==
• Within secure boundaries of the Nevada Test Site. ==

What is Yucca Mountain?

• A site slated by the federal gov’t to store all nuclear waste from power plants, weapons program, etc. ==

Why Yucca Mtn?

• Remote ==
• Dry climate ==
• Stable geology ==
• Deep water table ==
• Closed water basin ==

How do we get the stuff to Yucca?

• Nat’l experience to date ==
  • 2,700 shipments ===
  • 1.6 million miles ===
  • 30 years; ===
  • → No harmful release of radiation ===
• Similar to Europe’s safety record- travel shorter distances, but more densely populated ==

Transportation of Nuclear Waste

• Highly regulated ==
• DOT and NRC regulations ==
  • Containers ===
  • Advance route approvals ===
• Each state’s governor can specify
• Local trained emergency response teams (34 states)
  • Escorts ===
  • 24-hr satellite surveillance ===

Scenario

• A shipment to Yucca Mountain goes flying off an elevate section of the FDR ==
• FDNY calls to confirm this and informs you that you will be getting 5 victims. ==
• Soon after this 6 ambulatory patients with minor injuries show up. EMS soon brings 2 critically injured patients and 5 patients with compound fractures. ==
• What is the most important next step in addition to mobilizing the mass casualties’ disaster plan? ==
• In any explosion consider a “dirty bomb”. ==
  • So, radiation detection device required ===
• Screen background radiation. If > 2x → contaminated. ==
• For gross screening, may be able to use the radiation detection monitor used to monitor radioactive waste from the hospital. ==

= LUDLUM M-3 SURVEY METER =

• PPE with an N95 respirator, coveralls/gloves, and eye shields should be worn by personnel treating patients ==
• PAPR’s and full Decon suits are overkill, unless suspect simultaneous chemical contamination! ==
• If life saving treatment is done without PPE (personal protective equipment), providers will need to be screened, change clothes and shower as well. ==
• Personal electronic dosimeters should be worn as soon as available ==
• The detection device confirms that all these patients are contaminated. DOE sends out word that Cesium 137 has been confirmed as the radioactive agent. No other toxic substances are identified. ==
• What are the next steps? ==
• Tendency is to run away from these victims out of fear of suffering harm to oneself. Wrong and unethical. ==
• Treatment of the LIFE-THREATENING traumatic injuries should take place ASAP, even before decon is done. ==
• Should don quick respiratory, eye and contact protection as in routine trauma. ==
• IT IS IMPOSSIBLE FOR A LIVING PATIENT TO BE SO CONTAMINATED AS TO POSE AN IMMEDIATE HEALTH THREAT TO MEDICAL PROVIDERS. ==
• This is in direct contrast to chemical contamination situations, where there is indeed an immediate hazard to health care providers. ==
• That being said, non-life-threatening injuries will allow time for screening for radioactivity to take place. Remember, radioactive particles are PARTICLES, and can be washed and stopped by PPE (thin Tyvek suits with hoods, gloves, and respiratory face protection and eye shields). ==
• If mixed chemical/radiologic incident is suspected, then treat as a chemical incident with greater PPE consideration. ==
• All victims must be screened for radiation. Those that test positive will need to be decontaminated. ==
• In the meantime, you will need to treat the most severely injured. ==

Decontamination

• All victims need nasal swabs to assess degree of exposure prior to showering. Best if done <1 hour after exposure. ==
• Treat the immediate victims first, then shower them (on gurneys). ==
• All others can be showered, screened, and then treated. ==

Decontamination

• Due to inhalation or ingestion, some victims may not be totally decontaminated. Admitted to special isolation rooms as determined by hospital administration and Radiation Safety Officer. ==
• Radiation may not be detected externally even if ingestion has occurred (hence the nasal swabs, and save body secretions is important) ==

Treatment

• All victims should have nasal swabs done to assess degree of exposure.
• Urine, feces, vomitus should be collected as well, with names and times labeled.
• Assess samples for radioactivity.
• Internal decontamination may be necessary

Treatment- internal decontamination

• Potassium iodide- to protect thyroid if I 131 is suspected ==
• gastric lavage within 1-2 hrs. until fluid is , 2x background radiation. ==
• Antacids (AlOH, MgCO3) reduce GI uptake ==
• Dulcolex or fleet’s phosphosoda cathartic enemas. ==

Treatment

• Vomiting- use 5-HT3 blockers (Zofran, Anzemet) ==
• Draw blood for CBC, ALC, HLA, and Chromosome analysis in consultation with hematology. ==
• CBC with an absolute lymphocyte count should be done. A drop of 50% in 24–48 hours has prognostic significance. ==
• Consider anti viral and antibacterial prophylaxis in consultation with ID. ==
• Isolation if pancytopenia is a risk. ==

Treatment

• Prostaglandin (misoprostol) analogues in consultation with GI may prevent GI bleed. ==
• Colony stimulating factor may help those at risk for pancytopenia. ==
• DTPA-chelates plutonium and other transuranic elements ==
• Prussian blue- chelates thallium and cesium ==
• Consult Nuclear Medicine as well for general management. ==

Treatment

• Amifostine- free radical scavenger, protective of cell membranes and DNA. ==
• Clinically used to offset mucositis of RT. ==
• Side effects- n/v, hypotension. ==
• Protective pre exposure, may be valuable for first responders (and us!). ==
• Post exposure not shown to help ==

Great websites

• www.orau.gov ==
• www.CDC.gov ==
• www.gnyha.org ==

Acute radiation sickness

• ARS results from direct exposure to radiation from either particles or beams. ==
• Initially N/V ==
• More severe exposure → diarrhea, shock, and AMS ==
• Advanced symptomatic state from radiation exposure alone → unlikely to survive. But, can be difficult to distinguish from trauma related symptoms if an explosion has occurred. ==

In absence of injury

• Acute Radiation Sickness – 4 phases: ==
  • Prodromal phase-nausea /vomiting or no symptoms. ===
  • Latent phase –recovery ===
  • Manifest Illness phase- heme (anemia, infection), GI sloughing, bleeding and fluid loss. ===
  • Recovery or death. ===