heat related illness
play

Heat-Related Illness David E. Olson, M.D. U of MN TPC 2013 Miami Agenda Physiology Predisposition Acclimatization Heat related illnesses Prevention Physiology We are homeothermic Regulate or own warm-blooded

0 downloads 3 Views 580 KB Size Report
  1. Heat-Related Illness David E. Olson, M.D. U of MN TPC 2013 Miami

  2. Agenda • Physiology • Predisposition • Acclimatization • Heat related illnesses • Prevention

  3. Physiology • We are homeothermic – Regulate or own warm-blooded body temp • Maintain “normal” range – 96.4 - 99.1 degrees F

  4. Physiology • Body’s ability to regulate core temp depends on internal and external factors • How heat is produced: – Basal Metabolism • Increases with increased core temp – 10 percent elevation in BMR per 0.6 degree C rise – Exercise • Heat production 15-20x greater during exercise – External Heat Sources

  5. Physiology • Hypothalamus is critical in heat physiology (the thermoregulation center) – Helps to control: • Cutaneous blood flow (sympathetic) • Sweat glands (parasympathetic) • Cardiac output • Stroke volume • Usually efficient in a healthy individual – 1 degree C change in core temp for every 25-30 degree C change in ambient temp • Chronic Disease/Meds/Poor Conditioning are risks for impaired control

  6. Physiology • How do athletes control heat? – Conduction – Convection – Radiation – Evaporation • Work simultaneously

  7. Conduction • Occurs when the body comes in contact with something cooler • Heat is transferred to the cooler object

  8. Convection • When cool air passes over the skin • Lifts heat away • Windy days • Fans

  9. Radiation • Heat released from the body directly into the environment

  10. Evaporation • Sweat on the skin taking heat away from the body • **The primary thermoregulatory mechanism when the ambient temp is above 20 degree C (68 degrees F) • Need to be hydrated to maximize this! • Incorporates processes of convection and radiation

  11. Physiology • Assuming healthy athlete – These 4 mechanisms are dependent on gradients of temp and moisture – As temp and humidity increase these are less efficient – Evaporation becomes the key in hot conditions!! • Any process that limits this causes issues – Dehydration – Clothing

  12. Risk Factors Endogenous • Acute Illness (fever, gastroenteritis) • Chronic Illness (DM, CAD) • Sleep deprivation • Obesity • Eating disorders • Poor acclimatization • Inexperience • Motivation • Dehydration – 1% decrease in body weight can increase risk of heat illness • Sickle Cell Trait • History of Heat Illness • Extremes of age (Elderly and Kiddos)

  13. Risk Factors Exogenous • Alcohol • Stimulants • Drugs of abuse • Meds – Anticholinergics, antihistamines, beta blocker, diuretics, neuroleptics, benzos, calcium channel blockers, tricyclic antidepressants and stimulants • Environment – Temperature, humidity

  14. Children and Heat • Special cases – Produce more metabolic heat proportionately – Core temp rises faster when dehydrated – Smaller organ systems – Less efficient with heat dissipation

  15. Acclimatization • Physiological adaptation to hot, humid environment • 7-10 days • Changes: – Increase in blood volume (10-25%) – Increase in stroke volume – Decrease in resting HR – Sweat changes (earlier, more, dilute) – Skin vasodilates earlier

  16. Heat Illness • A spectrum of issues can occur • Can occur anytime • More likely in hot/humid weather • Remember: – Heat production is 15-20 greater with exercise!!! • 240 deaths annually • 3rd leading cause of death among US high school athletes

  17. Heat Illness Monitoring • Patient monitoring – Rectal temperatures – Pill monitoring devices

  18. Heat Index Air Temp/Humidity

  19. Heat Illness Monitoring Major Risk in Heat Illness is high ambient temp with combined high level humidity • Wet Bulb Globe Temperature – Helps quantify the risk of heat injury • Takes in to account – Ambient temp – Radiant heat – Humidity • WBGT=0.7WB + 0.2BG + 0.1DG

  20. WBGT • WB – Thermometer with bulb covered with a wet cotton wick – Simulates the evaporation of sweat – Integrates effects of humidity, wind and rad • BG – 6 inch black globe – Radiation and wind • DG – Shielded thermometer from radiation – What is usually reported as the temp

  21. Wet Bulb Globe Temperature Different Classifications of WBGT: Military ACSM Green/Low 80-84 <65 Yellow/Medium 85-88 65-73 Red/High 88-90 73-82 Black/Very High >90 >82

  22. WBGT Devices

  23. Heat Illness Spectrum • Heat Edema • Heat Syncope • Heat Cramps • Heat Exhaustion • Heat Stroke

  24. Heat Edema • Mild • Transient peripheral vasodilation • Orthostatic pooling • Mild dependent edema on exam

  25. Heat Syncope • Syncope or pre-syncope caused by decrease in vasomotor tone causing venous pooling • Un-acclimatized or dehydrated athletes • Usually at conclusion of exercise (worry if athlete collapses prior to finish) • Treated with rest, elevation of legs and fluids • Can return to activity after resolution of symptoms

  26. Heat Cramps • Localized, involuntary and sustained contractions of skeletal muscle • Causes: – Sodium and/or chloride depletion – Dehydration • Poorly conditioned athlete can lose more sodium along with fluid than a conditioned athlete – Impaired circulation in working muscles – Alterations in spinal neural reflex activity increased by fatigue

  27. Heat Cramps • Intensity dependent • Individuals predisposed • Poorly conditioned • Sickle Trait? • Fatigue • Game vs Practice • Dehydration • Supplement use

  28. Heat Cramps: Treatment • Stretching • Massage/Ice • Fluids – Oral – IV • Drugs – Valium – Quinine

  29. Heat Cramps • Return to Play – Rule out further Heat Illness – Resolution of symptoms – Correction of any underlying issues – Can be same day

  30. Heat Exhaustion • Most common form of Heat Illness • Temp usually from 38 degrees C (100.4 F) to 40 degrees C (104 F) • Numerous symptoms or signs that happen with exercise in warm humid conditions • Can result from volume/sodium depletion

  31. Heat Exhaustion Signs and symptoms • Elevated temp • Weakness • Elevated respiratory • Thirst rate • Nausea • Elevated pulse • Vomiting • Narrowed pulse • Dizziness pressure • Cramps • Headache • Sweating • Malaise • Mild Mental Status • Fatigue Alteration

  32. Heat Exhaustion Evaluation/Treatment • Obtain Core Temp!!!!! – Rectal • Rest – Decrease heat production • Shelter/Shade – Remove from the hot environment – Minimize exposure to heat • Cooling – Fans/Ice tub/Towels • Fluids – PO usually in these case – IV

  33. Heat Exhaustion Return to play • Resolution of symptoms • Normal Vitals • Normal hydration status • If in doubt……hold ‘em out – Symptoms can return quickly and progress to Heat stroke!! • Transfer if not improving or progressing to heat stroke

  34. Heat Stroke • Life threatening clinical syndrome characterized by loss of temperature regulation capabilities • Second most common cause of death in athletes in US • Risk dependent upon: – Endogenous heat production – Temperature/humidity – Individual predisposition

  35. Heat Stroke Presentation • Core temp now getting over 40 degrees C (104 F) • Similar presentation to Heat exhaustion • Onset can be sudden

  36. Heat Stroke Additional Signs/Symptoms • Classic Triad – Hyperpyrexia – Anhydrosis – Mental Status Changes • Confusion • Delerium • Ataxia • Seizures • Coma

  37. Heat Stroke Additional Signs/Symptoms • Tachycardia • Hypotension • Arrhythmias • Metabolic disturbance • Clotting disturbances • Rhabdo (Sickle Trait) • Renal and Hepatic collapse

  38. Heat Stroke Treatment • REMOVE FROM HEAT!! • Obtain Rectal Core Temp • ABC’s • Immediate cooling, if able, prior to transport • Then transport!!!

  39. Heat Stoke • With prompt recognition and treatment survival rate is high (90-100 percent) • The key is early recognition and treatment (cooling)

  40. Heat Stroke Cooling Methods • Ice water immersion • Ice water blankets – Fans • Ice packs • Evaporative cooling – Cool water/Warm air – .31 degrees C/min

  41. How we roll in Minnesota

  42. Heat Stroke • Prognosis- dependent of length of time and severity of hyperthermia • Return to play – May take some time – Normalize labs – Symptom resolution – Hydration status – Gradual

  43. Exertional Hyponatremia • Low sodium due to over-hydration in prolonged exercise with dilute fluids • Presents with: disorientation, pulmonary edema, seizures, coma • Rx- recognize and transfer • Prevention- avoid over hydration with dilute fluids during prolonged exercise • More frequent seen with extreme endurance events

  44. Heat Illness Prevention • Acclimatization • Illness control • Fitness • Medications • Conditioning • Education • Clothing • Environment risk assessment • Nutrition • Timing of event • Hydration • Monitoring of • Sleep conditions at event!

Recommend Documents


beat the heat
BEAT THE HEAT & KEEP COOL:

BEAT THE HEAT & KEEP COOL: OUTDOORS WHAT YOU NEED TO KNOW TO PREVENT

thursday february 27 2014 7 00 am registration breakfast
THURSDAY, FEBRUARY 27, 2014 7:00 am

TABLE OF CONTENTS Course Overview Information Faculty Disclosures Course

heat illness prevention applies to outdoor places of
HEAT ILLNESS PREVENTION Applies to

HEAT ILLNESS PREVENTION Applies to outdoor places of employment.

resilient the hague
RESILIENT THE HAGUE Anne-Marie

RESILIENT THE HAGUE Anne-Marie Hitipeuw Chief Resilience Officer , City of

sick building syndrome and building related illness
Sick Building Syndrome and

Sick Building Syndrome and Building-Related Illness Claims: Defining the

1 9
1 9 S C H O O L N U R S E R E S P O N

C O V I D - 1 9 S C H O O L N U R S E R E S P O N S E COVID-19 Illness

a study of heat related factors caused by color selection
A Study of Heat Related Factors Caused

A Study of Heat Related Factors Caused by Color Selection of Hard Hats and FRC

tracking cold related illness in massachusetts
Tracking Cold Related Illness in

Tracking Cold Related Illness in Massachusetts Photo: "Boston Winter

constraints on global carbon and heat exchanges from
Constraints on global carbon and heat

Constraints on global carbon and heat exchanges from measurements of

mental illness in the
Mental Illness in the Workplace

Yes Virginia, There is Mental Illness in the Workplace Stephanie Mitchell

case presentation
Case Presentation Maha Akkawi, MD,

Case Presentation Maha Akkawi, MD, Fatima Obeidat, MD, Tariq Aladily, MD

inflammatory responses and immune
inflammatory responses and immune cell

PUFA-derived bioactive lipids mediate inflammatory responses and immune cell

plasma membrane microdomains organize biochemical
Plasma membrane microdomains organize

Plasma membrane microdomains organize biochemical reac2ons to transduce

sementis agm november 2018 ceo presentation
Sementis AGM November 2018 CEO

Sementis AGM November 2018 CEO Presentation 1 Disclaimer We believe that

rationales behind novel therapies for coeliac disease
Rationales behind novel therapies for

Rationales behind novel therapies for coeliac disease Ludvig M. Sollid

non clinical approaches for immunogenicity assessment
Non-clinical approaches for

Non-clinical approaches for immunogenicity assessment: predictive models

corporate presentation
Corporate Presentation July 2016

Corporate Presentation July 2016 Forward-Looking Statements This

understanding osha recordability amp
UNDERSTANDING OSHA RECORDABILITY &

UNDERSTANDING OSHA RECORDABILITY & WC COMPENSABILITY Presented by: John

good questions for good health
Good Questions for Good Health

Good Questions for Good Health Department of Health and Human Services

feasibility in all settings
Feasibility in all settings Dr Kim

Feasibility in all settings Dr Kim Thomas Centre of Evidence Based

how can cannabis improve behavior symptoms in patients
How Can Cannabis Improve Behavior

5/14/19 How Can Cannabis Improve Behavior Symptoms in Patients with Autism?

10 th december 2015 at manor view practice booze and
10 th December 2015 at Manor View

10 th December 2015 at Manor View Practice. Booze and Drugs Presentation. This