Managing Environmental Emergencies

Documents to Request

• EMS run sheet with field vital signs and interventions
• Core temperature measurements with method and times
• Serial laboratory results (BMP, CBC, coagulation, CK, lactate, LFTs)
• ECG (Osborn/J waves for hypothermia, QTc for heat stroke)
• Toxicology consultation notes (for envenomation)
• Poison control center documentation
• Environmental conditions at scene (ambient temperature, water temperature, altitude)
• Prior medical history and medication list

Step 1: Heat Stroke Recognition and Cooling Protocol

Classification

Cooling Methods (Target: reduce core temp to 39°C within 30 minutes)

1. Cold water immersion (CWI): Most effective method; cooling rate 0.2°C/min. Immerse to neck in ice water bath. Gold standard for exertional heat stroke.
2. Evaporative cooling: Undress patient, mist with lukewarm water, fan continuously. Cooling rate 0.05°C/min. Use when immersion is impractical.
3. Ice packs to groin/axillae/neck: Adjunctive only—insufficient as sole method
4. Cold IV fluids: 4°C NS at 30 mL/kg—adjunctive, helps with volume
5. Peritoneal lavage/thoracic lavage: For refractory cases unresponsive to external cooling

Stop active cooling at 38.5-39°C to avoid overshoot hypothermia. Monitor continuously with rectal or esophageal probe.

Complications to Monitor

• Rhabdomyolysis (CK, urine myoglobin, maintain UOP >1 mL/kg/hr)
• DIC (PT/INR, fibrinogen, D-dimer, platelet count)
• Acute kidney injury (creatinine, BUN, electrolytes)
• Hepatic failure (AST/ALT, bilirubin—may peak at 48-72 hours)
• ARDS (serial chest X-ray, oxygenation status)

Step 2: Hypothermia Classification and Rewarming

Swiss Staging System

Rewarming Protocols

Critical rules for hypothermic cardiac arrest:

• Do NOT declare death until the patient is warm (core temp >32°C) and remains in arrest: "No one is dead until they are warm and dead"
• Limit defibrillation to 3 attempts if core temp <30°C; subsequent shocks are unlikely to convert until rewarmed
• Withhold IV medications (epinephrine, amiodarone) until core temp >30°C; space at double normal interval (every 6-10 min) between 30-35°C
• Continuous high-quality CPR or mechanical CPR device for transport
• Early ECMO/cardiopulmonary bypass is the definitive rewarming method for HT-IV with cardiac arrest

Step 3: Submersion Injury (Drowning)

1. Begin CPR immediately for pulseless patients—do not attempt to drain water from lungs
2. Assume cervical spine injury if diving, surfing, or unknown mechanism
3. Fresh vs. salt water: The clinical distinction is irrelevant for acute management—both cause surfactant washout, alveolar collapse, and ARDS
4. Intubate early for significant aspiration—high PEEP ventilation strategy (similar to ARDS protocol)
5. Core temperature: all drowning patients may be hypothermic—check and rewarm
6. Prognostic factors: submersion time >25 minutes, CPR >25 minutes, initial pH <6.8, and initial GCS 3 are associated with poor neurologic outcome but should not be used to terminate resuscitation in the field

Step 4: Envenomation Assessment and Antivenom Protocol

Crotalid (Pit Viper) Envenomation — North American

Antivenom administration: CroFab (crotalidae polyvalent immune Fab) — initial dose reconstituted in 250 mL NS, infuse over 60 minutes. Monitor for anaphylaxis (skin test is NOT predictive and is NOT recommended). Repeat dosing every 6-8 hours as maintenance (2 vials x 3 doses) to prevent recurrent coagulopathy.

Coral Snake Envenomation

• Fixed front fangs, minimal local findings, delayed neurotoxicity (2-13 hours)
• Antivenom (if available) should be given prophylactically for confirmed coral snake bites, even before symptom onset
• Monitor for bulbar symptoms: ptosis, diplopia, dysphagia, respiratory failure
• Ventilatory support may be required for days to weeks

Step 5: Altitude Illness

Checkpoint B: Post-Draft Alignment (Mandatory)

1. Is the core temperature measurement method documented (rectal/esophageal vs. unreliable tympanic/axillary)?
2. For heat stroke: was time-to-target-temperature tracked and documented?
3. For hypothermia: was the rewarming method appropriate for severity stage?
4. For envenomation: was antivenom timing, dosing, and monitoring documented?
5. Are serial labs and imaging ordered to track expected complications?

Quality Audit

Guidelines

1. Core temperature defines severity—tympanic thermometers are unreliable below 34°C and above 40°C; insist on rectal or esophageal probe for environmental emergencies
2. Cold water immersion is the gold standard for exertional heat stroke—do not delay cooling for transport, diagnostics, or IV access; cool first, then do everything else
3. Shivering cessation in hypothermia indicates core temp below approximately 30°C—this is a clinical warning sign, not a reassuring finding
4. Do not use tourniquets for snake bites—arterial tourniquets increase tissue ischemia without proven benefit; pressure immobilization is only for neurotoxic species (coral snakes, non-US elapids)
5. Activated charcoal and wound incision/suction are contraindicated in snake envenomation—they do not remove venom and increase wound complication risk
6. Drowning is the preferred term—the terms "near-drowning," "dry drowning," and "secondary drowning" are deprecated per WHO and Utstein-style guidelines
7. Prophylactic antibiotics are NOT indicated for submersion injury—treat pneumonia only if it develops clinically
8. ECMO for refractory hypothermic cardiac arrest should be considered for any patient with core temp <28°C and no contraindications to resuscitation—coordinate early transfer to ECMO-capable center