Prevention of Ensuing Heat Stroke

1. Prevention of Ensuing Heat Stroke Karen K. O’Brien, MD, FAAFP

2. 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?

3. Rates of Heat Stroke and Heat Exhaustion at Fort Benning Source: AMSA/DMSS

4. 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

5. June 06 HWI vs. Temp Data: Fort Benning Environmental Science Division

6. 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

7. Risk Factors • Skin disease • Eczema • Poison ivy • Skin graft • Normothermia Heat Stress

8. Medications that inhibit thermoregulation • Anticholinergics • Antihistamines • Tricyclics • Stimulants • Diuretics • Antipsychotics • ACE inhibitors, B-blockers

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

10. 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

11. 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

12. 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

13. 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

14. 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?

15. 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

16. 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

17. 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

18. 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