--- module: 074-01 language: en chapter: 74 title: "Disaster, Remote, Rural, and Resource-Limited Medicine" module_title: "Mechanistic foundations, classification, normal variation, and clinical presentation" source_sha256: 5bc38b44d53375096539c8d05a75a408626f060712d7d3a5c932038b193d0061 --- # Foundations of austere and disaster medicine ## Core framing ### Ordinary physiology under constrained resources ### Greatest justified benefit, with individual dignity ### Scarcity changes priorities, not reasoning ## Defining events and settings ### Mass-casualty incident: needs exceed available resources ### Disaster: community function beyond local capacity #### Sudden or slowly evolving ### Impact set by vulnerability and exposure ### Remote, rural, resource-limited overlap #### Not interchangeable; local expertise matters ### Cycle: mitigation, preparedness, response, recovery #### Prevention often saves more than heroic response #### Recovery lasts years ## Triage under uncertainty ### Sort by urgency, benefit, resources ### Mass casualty favours likely survivors ### Shared protocol, not assumed colour terms ### Rapid initial assessment, detail sacrificed #### Airway, haemorrhage control, antidote change category #### Children need age-adjusted physiology ### Dynamic: retriage as conditions change #### Labels attached, legible, timed #### Over-triage consumes, under-triage delays ### Expectant does not mean no care #### Analgesia, warmth, presence remain obligations ## Command, zones, and communication ### Incident command roles #### Clinical expertise informs, not replaces #### Span of control limits direction ### Redundant communication methods ### Hot, warm, cold zones #### Scene safety precedes patient contact ### Distribute by capability and capacity ### Hospital internal surge plans ### Honest, consistent public messaging #### Rumours fill information gaps ## Injury patterns by mechanism ### Blast: primary to quaternary injury #### Tympanic rupture does not predict lung injury ### Chemical: route, persistence, latency, toxidrome #### Decontamination as urgent as antidote #### Undirected washing not universally safe ### Radiological: contamination versus irradiation #### Irradiated only patient does not expose staff #### Life-threatening trauma before decontamination ### Biological: unusual clusters and syndromes #### Natural and deliberate look identical early ### Crush: necrosis, hyperkalaemia, kidney injury #### Deterioration after release of compression #### Treat before extrication, avoid potassium ### Burns: airway oedema, circumferential risk #### Hypothermia common despite burns ### Floods, earthquakes, wildfire ## Austere physiology and environment ### Haemorrhage control and tourniquets #### Record tourniquet time, keep it visible #### Permissive low pressure not in brain injury ### Hypothermia worsens coagulation and shock ### Hyperthermia needs rapid cooling ### Altitude hypoxaemia and acclimatisation #### Descent and oxygen definitive ### Diving illness and gas embolism #### Flying after diving can precipitate symptoms ## Infrastructure-dependent disease ### Power failure disrupts oxygen, dialysis, cold #### Registries and backup plans preserving privacy #### Generator exhaust carbon-monoxide risk ### Displacement: crowding, malnutrition, violence #### Water, sanitation, shelter as core interventions ### Chronic disease interruption causes crises #### Formulary and continuity records in preparedness ## Cultural and local knowledge ### Communities know geography and evacuation ### Bypassing local leadership causes harm ### Language access and cultural safety build trust #### Historical mistreatment justifies suspicion ### Essential versus customary care