Environmental Injuries Co lin G. Ka ide, MD , FACEP, FAAEM, UHM Associate Professor of Emergency Medicine Board-Certified Specialist in Hyperbaric Medicine Specialist in Wound Care The Ohio State University Wexner Medical Center The Most Dangerous Drug Combination… Accidental Testosterone Hypothermia and Alcohol! The most likely victims… Photo: Ralf Roletschek 1 Definition of Blizzard Hypothermia of Subnormal T° when the body is unable to generate sufficient heat to sustain normal functions Core Temperature < 95°F 1979 (35°C) Most Important Temperatures Thermoregulation 95°F (35° C) Hyper/Goofy The body uses a Poikilothermic shell to maintain a Homeothermic core 90°F (32°C) Shivering Stops Maintains core T° w/in 1.8°F(1°C) 80°F (26. 5°C) Vfib, Coma Hypothalamus Skin 65°F (18°C) Asystole Constant T° 96.896.8-- 100.4° F 2 Thermoregulation The 2 most important factors Only 3 Causes! Shivering (10x increase) Decreased Heat Production Initiated by low skin temperature Increased Heat Loss Warming the skin can abolish Impaired Thermoregulation shivering! Peripheral vasoconstriction Sequesters heat Predisposing Predisposing Factors Factors Decreased Production Increased Loss –Endocrine problems Radiation Evaporation • Thyroid Conduction* • Adrenal Axis Convection** –Malnutrition *Depends on conducting material **Depends on wind velocity –Neuromuscular disease 3 Predisposing Systemic Responses CNS Factors T°< 90°F (34°C) Impaired Regulation Hyperactivity, excitability, recklessness CNS injury T°< 80°F (27°C) Hypothalamic injuries Loss of voluntary motion and reflexes Peripheral Injury T°< 75°F (24°C) Atherosclerosis Loss of corneal & oculocephalic reflexes Neuropathy Interfering Agents The patient can look dead! Systemic Responses The Infamous Osborn Wave Cardiovascular A form of early repolarization Above 90°F (32°C): Excitatory Tachycardia, Hypertension Elevated “J” Point Below 90°F (32°C): Inhibitory response Bradycardia at level of pacemaker cells Atrial and ventricular dysrhythmias “The Hypothermic Hump” Atrial Fib Vasodilatation 4 Systemic Responses Systemic Responses Pulmonary Renal Initially tachypnea is seen Cold diuresis occurs early T°<90< 90°F(32F (32°C) RR can fall to 5-10 Central hypervolemia ADH suppression Minute volume falls T°< 90°F (32°C): Kidney function proportional to metabolic rate declines Systemic Responses Systemic Responses Hematologic Hematologic Platelet Issues Thrombocytopenia Platelet dysfunction Cold coagulopathy can produce significant Coagulopathy bleeding Dysfunction Occurs by 2 mechanisms 5 Question? Question? Do people Although bleeding occurs, the really take off measured PT and PTT are usually normal - Why does this happen? thiheir c lot hes when freezing to death? Image from Ponder High School Cold Water Immersion- Cold Water Immersion Hmmm? Heat loss in cold water is 20- 30 times that of air! Many additional factors come into play in cold water immersion! Image from Chicago Tribune 6 Cold Water Death! January 13, 1982 Air Florida Flight 90 Death may occur in only 15 minutes but NOT from hypothermia Cardiac dysrhythmias-“Sudden“Sudden Disappearance” Breathing abnormalities Gasp, Hyperventilation Muscular dysfunction In water for 1 hour and 45 minutes before rescue! News Story - Chicago Tribune Hypothermia Effects Jimmy Tontlewicz • Video 1: Air Florida Flight 90 “A heroic story of survival” On Jan. 15, while sledding with his father, Jimmy plunged into the icy waters of Lake Michigan. When rescuers pulled him out, he had been submerged for at least 20 minutes and had no discernible heartbeat, pulse or breathing. In Chicago last week doctors said Jimmy is progressing so well that they hope to "Seconds from Disaster--The crash of Air Florida Flight 90 send him home this month. Video from National Geographic 7 Management and Rewarming of a Hypo therm ic Pa tient News Story - Chicago Tribune Emergency Medicine Dogma ...You’re already dead! You’re not dead until you’re... Warm and dead Unless... Drawn by friend-Kestutis Boyev 8 Treatment Death! Do Primary/Secondary Survey Still dead with T°> 32°C (90°F) Serum potassium > 10 Evaluate for other treatable conditions Documented and verified DNR orders! College newspaper: Daily Illini Rewarming Most Important Rule If the core temperature is less than 90°F (32°C) and shivering has stopped, YOU MUST ADD HEAT to the core! 9 Rewarming is Additive Rewarming: Passive Insulate and allow shivering to raise body temperature Appropriate for mild ++++++++ + + + + + + hypothermia Core Temperature > 32°C/90°F Healthy individuals Rewarming:Active Rewarming: Core Rewarming Often VERY complicated to perform ADD HEAT! Supplies heat directly to the core Necessary for most patients with a core temp < 90° Fast! 10 Treatment: Core What About heated IVFs? Rewarming Heated Humidified Air Is heated IVF an effective Heat to 45°C/113°F rewarming method? 2-3°FriseinTF rise in T°/hr Indicated for ALL significantly hypothermic patients Why is This? 70 Kg person is 60% water: = 42 L of fluid If 42 L of fluid is at 85°F and you add 1 additional L of fluid at 110°F...How much NO! difference does it make? Only 0.3°C/0.6°F per Liter 11 Treatment: Treatment: Core Rewarming Therapeutic Peritoneal Lavage Heated irrigation of body cavities Abdominal Irrigation (“TPL”) ~3°F/hr Thoracic Irrigation Very effective (up to 10°F/hr) Ant/post chest tubes Treatment: Thoracic Irrigation Treatment: Rewarming • Video 2: Thoracic Irrigation Extracorporeal Blood Rewarming Fem-Fem Bypass CAVR-Ll1IfLevel 1 Infuser V V R Dialysis with a heat exchanger 12 Microwaves? Treatment: Sinus Bradycardia Physiologically normal at T < 93°F/34°C Don’t treat it—Self-limited Treatment: Atrial Fibrillation Treatment: Ventricular Fib Occurs < 28°C/83.5°F Occurs Commonly at T < 86°F (30°C) Lidocaine is ineffective The rate is SLOW! Rewarm and defibrillate every few Resolves with treatment of Hypothermia degrees 13 Treatment: Asystole Other Treatments Occurs physiologically at T < CPR 65°F/18°C Only when no detectable May occur spontaneously pulse Onlyyp responds to rewarming Pressor agents Caution with cardiac stimulation HeatHeat--RelatedRelated Illness Statistics About 500 die each year in the U.S. Hard to know exact number because it’s often under- reported August 2003: at least 35,000 died in Europe I’m Feelin Hot, Hot , Hot! 14 Chicago, August, 1995 Pathogenesis of Heat Illness • Exogenous heat gain • Endogenous heat production Photo: Daniel Schwen • Decreased dissipation All tolled, 760 people, mostly the elderly and poor died that summer Pathogenesis: Wet Bulb Globe Temperature! Exogenous Gain A Weighted Average… • Environmental temperature • Sun, workplace, home, sauna • 10%: Dry, shaded thermometer • 70%: Wet thermometer • 20%: Unshaded black globe 15 Pathogenesis: Endogenous Pathogenesis: Endogenous Production Production • What are some other causes... • Basal metabolism: 50-60 kcal/hr/m2 • Hyperthyroidism • 1°C/hr increase in T° if we had no • Neuroleptic Malignant mechihanism fdiiti!for dissipation! Syndrome • Malignant Hyperthermia • Cocaine, Amphetamines, 20x Increase in heat production is MDMA, LSD seenExercise?? during exercise! • Fever Pathogenesis: Decreased Dissipation: Decreased Dissipation Dehydration Yeah…But it’s a dry • Limits Sweating heatheat!! • Volume overrides heat dissipation • Impairs CV function • Insensible water loss • Dehydration is the • 1.5L/day (2% BW) most significant factor • Exercise: 1-2 L/hr affecting the ability to • Maximum gastric emptying dissipate heat! • 1-1.5 L/Hr Hullraisere on Panoramio.com 16 QUESTION? Spectrum of Illness How much of the Heat Heat Heat Prickly lost fluid does Edema Cramps Syncope Heat thirst alone replace? Heat Exhaustion Only about 2/3 of the Heat needed fluids Stroke Heat Exhaustion Heat Exhaustion Flulike symptoms – malaise, headache, weakness, nausea, Cool shaded environment anorexia, vomiting Oral rehydration if capable Tachycardia, orthostatic but may need IVF due to hypotension large amoun tflts of volume ltlost as sweat Sweating is generally present Cooling is not necessary but Temperature is < 40°C (104°F) it can make the patient feel Mental status and neurologic better exam are normal 17 What is the Most Important Thing to Tell a Discharged Heat Exhaustion Patient??? Heat Stress For 48 Hours Heat Stroke Heat Stroke • Catastrophic, life-threatening Temperature > 40.5°C (105°F) emergency MENTAL STATUS CHANGES: • Failure of thermoregulatory Hallmark is severe CNS dysfunction mechanisms Confusion • Multisystem tissue/organ Delirium damage Seizures • Damage is a function of T° max Coma and duration of T° elevation 18 Multi-Organ Dysfunction Heat Stroke: Area of Confusion Encephalopathy Rhabdomyolysis Acute renal failure • Can the temperature be ARDS less than 105°F and still Myocardial/hepatocell be heat stroke?? ular/pancreatic Intestinal ischemia/infarction Bleeding complications – DIC www.gearfuse.com Heat Stroke: Area of Confusion Classic (Epidemic) Heat Stroke • Excess heat gain, impaired loss • Anhydrosis (sweat cessation) • Occurs during heat waves • Elderly, very young, • Sweat gland fatigue poor, debilitated • DhdDehydra tion • +/- inciting medications • Sweating can persist to T° > • Sweating is less likely 42°C (108°F) politicalhumor.com 19 Vikings football player dies of heat stroke Exertional Heat Stroke August 2, 2001 Posted: 6:26 AM EDT (1026 GMT) Korey Stringer died early Wednesday of heat stroke • XS heat production, overwhelmed loss mechanisms EDEN PRAIRIE, Minnesota (CNN) -- Pro Bowl offensive lineman