Prevention of Ensuing Heat Stroke

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Prevention of Ensuing Heat Stroke

• Karen K. OBrien, MD, FAAFP

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Overview

• Magnitude of the problem
• Primary Prevention
• Secondary Prevention
• Tertiary Prevention- treatment by nonmedical
  first responders is critical
• How do we apply this model to return to play/duty?

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Rates of Heat Stroke and Heat Exhaustion at Fort
Benning
Source AMSA/DMSS
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Prevention

• Primary
• Identification of individual risk factors
• Cumulative Risk- 3rd hot day of increased temps
  or heat wave
• Modification of training uniform and metabolic
  strain
• Heat dumping
• Risk management and mitigation procedures
• Secondary
• Sensitivity to milder forms of heat injury
• Modification of training when mild cases occur
• Use of buddy system to monitor meal and fluid
  intake
• Tertiary
• Use of buddy to monitor behavioral change and
  performance degradation
• Aggressive cooling at first sign of mental status
  change

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June 06 HWI vs. Temp
Data Fort Benning Environmental Science Division
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Risk Factors

• Age
• Anticholinergic medication
• Other drugs
• Increased body mass index
• Illness/DM/Spinal cord injury
• Skin disease
• Poor acclimation and conditioning
• Uniform/ Body Armor

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Risk Factors

• Skin disease
• Eczema
• Poison ivy
• Skin graft
• Normothermia Heat Stress

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Medications that inhibit thermoregulation

• Anticholinergics
• Antihistamines
• Tricyclics
• Stimulants
• Diuretics
• Antipsychotics
• ACE inhibitors, B-blockers

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Primary Prevention

• Heat Injury risk management process
• Acclimation guide for Ranger, Airborne and Elite
  students
• Label high risk medications and profile
  at risk soldiers

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Primary Prevention

• Air conditioning
• Acclimatization
• Hydration
• Exertion
• Modification of uniform/ training sites
• Remove headgear when not on field
• Increase spacing and positioning resting athletes
  in shade whenever possible
• Consider tentage next to training areas

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Heat Dumping

• Encourage cool showers and time in air
  conditioning between high exertion training
• If athletes are staying in dorms for summer
  training- check to ensure air conditioning is
  functioning

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Secondary Prevention

• Detection of milder forms of heat illness
• Use of those sentinel cases to modify training to
  prevent additional cases
• Screening for poor food and fluid intake

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Tertiary Prevention

• Tertiary prevention efforts focus on people
  already affected by disease and attempt to reduce
  resultant disability and restore functionality
• Rapid cooling intervention by first responders
  can reduce organ injury and prevent development
  of multi-organ dysfunction syndrome

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Return to Duty

• How refractory was Soldier to normalizing
  thermoregulation?
• Was there significant tissue injury?
• Was the heat stroke part of a large cluster of
  heat injuries or an isolated event?
• What were the risk factors and how easily can
  they be mitigated?

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Return to Duty

• Primary
• Identification of individual risk factors
• Cumulative Risk- 3rd hot day of increased temps
  or heat wave
• Modification of training uniform and metabolic
  strain
• Heat dumping
• Risk management and mitigation procedures
• Secondary
• Sensitivity to milder forms of heat injury
• Modification of training when mild cases occur
• Use of buddy system to monitor meal and fluid
  intake
• Tertiary
• Use of buddy to monitor behavioral change and
  performance degradation
• Aggressive cooling at first sign of mental status
  change

Patient and trainer education/communication is KEY
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Risk Factors

• Age
• Anticholinergic medication
• Other drugs
• Increased body mass index
• Illness/DM/Spinal cord injury
• Skin disease
• Skin graft or eczema?
• Poison ivy, cellulilits?
• Poor acclimation and conditioning
• Uniform/ Body Armor
• RECENT HEAT STROKE
• Sickle Cell Trait
• Environmental strain severe enough on day of
  injury to cause multiple injuries

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Return to Duty

• Case 1
• 19 yo from Alaska during 2 mi run
• Overweight
• Poor conditioning
• First week in Southeast
• Case 2
• Paratrooper on mission in Panama
• Case 3
• 47 yo during minimal exertion
• High blood pressure meds, diabetic, obese

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Summary

• Overview of Exertional Heat Illness
• Risk management is key
• Heat stress is cumulative
• Prevention1, prevention2, prevention3
• Identify risk factors and mitigate risk
• When early cases occur- modify training
• When heat strokes occur- rapid first responder
  intervention can prevent fatal complications from
  developing