Emergency Medicine: Hypothermia and Heat Illness

Hypothermia

• Core body temperature < 35°C (95°F)
• Mild: 32°C-35°C
• Moderate: 28°C-32°C
• Severe: < 28°C
• Complications: CNS dysfunction, acute kidney injury, acute hepatic necrosis, elevated troponin, leukocytosis, rhabdomyolysis

Heat Illness Treatment

• Treatment: Remove patient from heat, remove clothing, provide cooling measures
• Cooling temperature goal: 38°C-39°C
• Intubate: Intubate if altered mental status (AMS)
• IV access and fluid resuscitation: Provide IV access and fluid resuscitation
• Medications: Benzodiazepines and dantrolene can be used

Drowning and Near Drowning

• Near Drowning: 90% of near-drowning patients aspirate some water
• Complications: Hypoxia, V/Q mismatch and shunt, direct lung injury
• Salt Water vs. Fresh Water: The type of water aspirated does not significantly impact outcome
• Amount of Aspiration: Aspiration of water is typically < 3 mL/kg, not enough to cause salt-related pathologies (which require 22 mL/kg)

Addressing Drowning Myths

• Dry Drowning: This is a myth, there is no evidence to support it
• Post-Near Drowning Monitoring: Monitor patients for at least 6 hours after a near-drowning event
• Mammalian diving reflex and neuroprotection: Evidence supports improved outcomes in extreme hypothermia in drowning patients.

Poor Prognosis

• Submersion time greater than 5 minutes
• Delayed resuscitation
• Glasgow Coma Scale (GCS) score 3 with fixed pupils
• Low pH

Hypothermia

• Core temperature below 35°C (95°F)
• Classified by severity: mild (32°–35°C), moderate (28°–32°C), severe (<28°C)
• Leads to central nervous system dysfunction, acute kidney injury, acute hepatic necrosis, elevated troponin, leukocytosis, and rhabdomyolysis

Heat Illness Treatment

• Remove patient from heat source
• Remove clothing to aid in cooling
• Target cooling temperature: 38°–39°C
• Intubate if altered mental status is present
• Establish IV access and administer fluid resuscitation
• Consider benzodiazepines and dantrolene for treatment

Drowning & Near-Drowning

• Majority of patients aspirate some water during near-drowning events
• Potential complications include hypoxia, ventilation/perfusion mismatch and shunt, and direct lung injury
• Salt water versus fresh water aspiration does not significantly impact outcome
• Amount of water aspirated typically does not reach levels needed for salt-related pathologies (22 mL/kg)
• Average aspirate is roughly 3 mL/kg

Addressing Drowning Myths

• "Dry drowning" is a misconception, not supported by evidence
• Patients should be closely monitored for 6 hours following near-drowning events
• The Mammalian Diving Reflex may contribute to improved outcomes in extreme hypothermia during drowning events

Prognosticators of Poor Outcome in Drowning

• Submersion exceeding 5 minutes
• Delay in resuscitation efforts
• Glasgow Coma Scale score of 3 with fixed pupils
• Low pH levels

Hypothermia

• Core temperature below 35°C (95°F)
• Classified as mild (32°–35°C), moderate (28°–32°C), and severe (below 28°C).
• Can lead to central nervous system dysfunction, acute kidney injury, acute hepatic necrosis, troponin elevation, leukocytosis, and rhabdomyolysis.

Heat Illness Treatment

• Move patient to a cool environment, remove clothing, and initiate cooling measures.
• Target cooling temperature: 38°–39°C (100.4°–102.2°F).
• Intubate if altered mental status (AMS).
• Establish intravenous (IV) access and provide fluid resuscitation.
• Consider benzodiazepines and dantrolene for treatment.

Drowning and Near-Drowning

• 90% of drowning patients will aspirate water.
• Complications include hypoxia, ventilation-perfusion (V/Q) mismatch and shunt, and direct lung injury.
• Saltwater vs. freshwater aspiration does not significantly impact patient outcomes.
• Aspirated water volume is typically low (3 mL/kg) and insufficient to cause significant salt-related pathologies.

Addressing Drowning Myths

• "Dry drowning" is not a recognized medical term.
• Patients should be monitored for 6 hours after a near-drowning event.
• The mammalian diving reflex can offer neuroprotection in cases of extreme hypothermia during drowning.

Prognosticators of Poor Outcome

• Submersion time exceeding 5 minutes.
• Delayed resuscitation.
• Glasgow Coma Scale (GCS) score of 3 with fixed pupils.
• Low blood pH.

Hypothermia

• Core temperature below 35ºC (95ºF)
• Mild: 32º-35ºC
• Moderate: 28º-32ºC
• Severe: < 28ºC (105ºF)
• Can lead to CNS dysfunction, acute kidney injury, acute hepatic necrosis, elevated troponin, leukocytosis, and rhabdomyolysis

Heat Illness Treatment

• Remove patient from heat source
• Remove clothing
• Cool patient down
• Cooling temperature goal: 38º-39ºC
• Intubate if altered mental status
• Establish IV access and start fluid resuscitation
• Consider using benzodiazepines and dantrolene

Drowning

• 90% of near drowning patients will aspirate some water
• Complications include hypoxia, ventilation/perfusion mismatch and shunt, and direct lung injury
• No difference in patient treatment outcomes based on salt vs freshwater aspiration
• Human body rarely aspirates enough water to cause significant salt-related pathologies
• Typical aspirate is 3 mL/kg
• Dry drownings are a myth
• It is important to monitor patients for at least 6 hours after a near-drowning event
• Mammalian Diving Reflex may offer neuroprotection, specifically with drowning patients in extreme hypothermia
• Prognostic indicators of poor outcome include greater than 5 minutes of submersion, delays in resuscitation, GCS 3 with fixed pupils, low pH levels

Hypothermia

• Core temperature below 35°C (95°F)
• Classified into three categories:
  • Mild: 32°C-35°C
  • Moderate: 28°C-32°C
  • Severe: Below 28°C
• Severe hypothermia can lead to:
  • Central nervous system dysfunction
  • Acute kidney injury
  • Acute hepatic necrosis
  • Elevated troponin levels
  • Leukocytosis
  • Rhabdomyolysis

Heat Illness Treatment

• Remove the patient from the heat
• Remove constrictive clothing
• Implement cooling measures
• Target cooling temperature: 38°C-39°C
• Intubate if altered mental status (AMS)
• Establish IV access and initiate fluid resuscitation
• Consider benzodiazepines
• Dantrolene may be administered

Drowning & Near Drowning

• Approximately 90% of drowning victims aspirate water
• Complications:
  • Hypoxia
  • Ventilation/perfusion mismatch and shunt
  • Direct lung injury
• The type of water aspirated (salt vs. fresh) is not a significant factor
• The amount of aspirated water is usually insufficient to cause significant electrolyte imbalances
• Myth: "Dry Drowning" is not a real phenomenon
• Monitoring is needed 6 hours post near-drowning event
• Mammalian diving reflex and neuroprotection may improve outcomes in cases of extreme hypothermia during drowning

Prognosticators for Poor Outcome

• Submersion exceeding 5 minutes
• Delayed resuscitation
• Glasgow Coma Scale (GCS) score of 3 with fixed pupils
• Critical pH level

Hypothermia

• Core temperature less than 35°C (95°F)
• Mild: 32°C-35°C
• Moderate: 28°C-32°C
• Severe: 105°F
• CNS dysfunction
• Acute kidney injury
• Acute hepatic necrosis
• Elevated troponin
• Leukocytosis
• Rhabdomyolysis

Heat Illness Treatment

• Remove from heat, remove clothing, cooling
• Cooling temperature goal: 38°C-39°C
• Intubate if altered mental status (AMS)
• IV access and fluid resuscitation
• Benzodiazepines
• Dantrolene

Drowning

• 90% of patients will aspirate some water
• Complications:
  • Hypoxia
  • V/Q mismatch and shunt
  • Direct lung injury
• Salt water vs. Fresh water: Doesn’t Matter
• Amount of aspirated water is not enough to make a difference
• Need 22 mL/kg for salt-related pathologies
• Usual aspirate is 3 mL/kg

Drowning Myths

• Dry drownings are not real
• Monitor 6 hours post near-drowning event

Mammalian Diving Reflex

• Evidence supports improved outcome in extreme hypothermia in drowning patients

Prognosticators of Poor Outcome

• Greater than 5-minute submersion
• Delay in resuscitation
• GCS 3 with fixed pupils
• pH

Test your understanding of hypothermia, heat illness treatment, and drowning complications. This quiz covers essential definitions, treatment protocols, and complications associated with these critical conditions. Assess your knowledge on how to manage these emergencies effectively.