All-Hazards

All-hazards describes a holistic approach to chemical, biological, radiological, and nuclear threats, both weaponised and non-weaponised.

Agents are classified by:

• Degree of harm:
  • Damaging
    e.g. Mustard gas, low-dose radiation.
  • Incapacitating
    
  • Lethal
    e.g. Cyanide, nerve agents, inhaled anthrax, high-dose radiation.
• Physical properties
  • Persistent
    Require decontamination to be removed.
  • Non-persistent
    Exposure can be limited by ambient conditions or removal from the area.
• Route of exposure
  • Inhalation
  • Ingestion
  • Inoculation
  • Transcutaneous

Agents

Hazards include:

• Chemical
• Biological
• Nuclear
• Radiological

Chemical

• Military operations
• Incapacitating or lethal
• Inexpensive
• High casualties

Nerve agents:

• Rapidly organophosphate compounds that irreversibly inactivate anticholinesterase, causing an anticholinergic toxidrome
• Include:
  • Sarin

Cyanides:

Cyanide is covered under Cyanide Toxicity.

• Inhibit cytochrome oxidase, impairing erobic respiration and leading to refractory lactic acidosis

Vesicants:

• Alkylating agents inhibit cellular glycolysis, causing necrosis
• Include:
  • Mustard gas
    Supportive treatment for:
    • Temporary blindness
    • Airway burns
    • ARDS

Pulmonary agents:

• Injury via direct damage or inducing an inflammatory response
• Include:
  • Chlorine
  • Phosgene

Biological Agents

Infecting people, fauna, or flora with a disease or toxin. Classified into:

• Live agent
  • Small pox
  • Plague
• Toxin
  • Anthrax
  • Botulinum toxin
  • Ricin

Radiological and Nuclear

• Intentional
  Explosion or covert radioactive source.
• Workplace exposure

Depending on the nature of the exposure, a patient may suffer:

Types of radiation:

• Alpha particles
  Charged helium nuclei which are stopped by ~20μm of tissue. May cause internal contamination only. Stopped by clothing and mask.
• Beta particles
  Energised electrons that can penetrate skin. May cause external or internal contamination. Stopped by plastic or sheet metal.
• Gamma
  High energy ionising radiation. Requires dense shielding.

• Irradiation
  Exposure to ionising radiation.
• External contamination
  Radioactive material in contact with hair, skin clothing.
• Internal contamination
  Radioactive material inhaled or ingested.
• Wound contamination
  Wounds containing radioactive blast-fragmentation.
• Combined

Clinical Manifestations

Diagnostic Approach and DDx

Investigations

Bedside:

Laboratory:

Imaging:

Other:

Management

Resuscitation:

Specific therapy:

• Pharmacological
• Procedural
• Physical

Supportive care:

Disposition:

Preventative:

Marginal and Ineffective Therapies

Anaesthetic Considerations

Complications

Prognosis

Key Studies

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References

1. Bersten, A. D., & Handy, J. M. (2018). Oh’s Intensive Care Manual. Elsevier Gezondheidszorg.