ENVIRONMENTAL DISORDERS BRADEN MCINTOSH

OBJECTIVE Burns Freezing injuries Hypothermia Hyperthermia

BURNS

EPIDEMIOLOGY burns per year admissions 4000 deaths

PATHOPHYS: DISRUPTION OF CELL MEMBRANES Disrupts sodium pumps Efflux of K Release of histamines, kinins, arachidonic acid, oxygen radicals Increased svr Met acidosis Increased hct Local injury

RULE OF 9'S

MANAGEMENT Airway- enclosed space Pain control Parkland formula- give lr Watch for rhabdo Local wound care: bacitracin, silvadene, jelly gauze Escharotomy if circumferential

DISPO Minor burns- < 15% bsa partial or 2% full - dc Moderate % partial and 2-10% full- admit Major- >25% partial or 10% full, hands, face, major joint, feet - burn center

COLD INJURIES

PATHOPHYS Capillary stasis and thrombosis (hunting response) Ice crystal formation Reperfusion injury- txa, pge, endothelial damage, clumping, sludging, tissue loss

TRENCHFOOT Non-freezing injury Prolonged cooling accelerated by wet conditions Nerve damage Numbness. Tingling Tx: supportive- keep feet clean, warm, dry, elevated

CHILLBLAINS Non freezing dry injury Erythematous, pruritic and burning paresthesias Tx- supportive: rewarming, loose dressings, topical steroids

FROST BITE: PRESENTATIO N Superficial (skin soft) - vesicles> black and hard skin> sloughing Deep (hard)- hemorrhagic vesicles> mummification and sloughing Can't tell degree until reperfusion

FROST BITE MANAGEMENT Rapid rewarming circulating water deg Tetanus Wound care- debride clear vesicles, leave hemorrhagic ones, dress wounds, aloe Ibuprofen Pen G

HYPERTHERMIA

PATHOPYHS Normal body regulation fails Excess heat > protein desaturation > cell death and endothelial damage dehydration > cardiovascular and metabolic derangements Heat cramps, exhaustion, stroke

HEAT CRAMPS Painful involuntary contractions 2/2 def of sodium and potassium Tx- fluids and salt replacement

HEAT EXHAUSTION 2/2 hyponatremia or hypovolemia Presents as ha, n, vom. No cns impairment Temp not > 40 Tx: cool environment and fluids

HEAT STROKE Heat exhaustion plus temp > 40 and/ or ams Classic vs. exertional Mortality % Tx: cooling- evaporative is best, can do immersion, benzos for inappropriate shivering, avoid pressors Stop once you get to core of 39 Watch for renal failure. Hematologic disorders, respiratory distress and seizures

HYPOTHERMIA

PREDISPOSIN G FACTORS Drunk Hypoglycemia malnutrition addison's Infection myxedema

PATHOPHYS Defined as core temp < 35 Excitation and slowing phases Cardio- inc bp, hr, co > 32 degrees then all downhill, j waves, brady> afib > vfib> asystole Pulm- left shift of oxy hgb curve, abg looks better than it really is GI- pancreatitis and hepatic dysfxn Heme- enzyme malfxn> dic Renal- atn and volume depletion Nervous- cns depression

MANAGEMENT: REWARMING passive external- warm env, remove clothes active external- forced air, warming blanket, warm water immersion active internal- heated iv fluids, gastric, peritoneal, bladder lavage, bypass, chest tubes Shock once Don't give insulin Can't pronounce until 35 degrees

QUESTION #1 30 y/o m p/w eythematous tingly lesion on tips of toes after dry cold not < freezing. Dx? Frostnip, frost bite, trench foot, chillblains

QUESTIONS?

BILBOIOGRAPHY Tintinalli, et al. Tintinalli's emergency medicine: a comprehensive study guide. Environmental disorders. Marx, hockberger. Rosen's emergency medicine- concepts and clinical practice. Environmental disorders. Rivers. Preparing for the written board exam in emergency medicine. Environmental disorders. Hippo EM