temp-related EM Flashcards
heat edema
seen early, mostly in elderly, inc. aldosterone, self-limited
heat tetany
2/2 hyperventilation. paresthesias, carpopedal spasm, tetany. self-limited, tx by removing person from heat
heat rash
pruritic, erythematous rash on clothing-covered body parts. inflammation of obstructed sweat glands, tx w/antihistamines, avoid heat, light/loose clothing
heat syncope
early in heat exposure, combo of vasodilation, dec. vasomotor tone, mild dehydration, tx in cool environment w/rehydration, check for injuries and other syncope causes, esp. in elderly pts
heat cramps
seen when cooling muscles off, likely 2/2 hypo Na/hypoCl from water w/o lytes, needs salt + fluids, may be predisposed to malignant hyperthermia
heat exhaustion
excessive hater/salt loss, generally develops over days, non-specific Sx (HA, H/V, diarrhea, LH, diaphoresis, malaise, myalgias), temp <40C, normal neuro exam, may be hard to distinguish from resolving heat stroke, tx as above
heat stroke
AMS w/core temp >40.5C (105), peripheral cooling precedes central cooling so temp may be a bit lower, seen often in pts w/compromised homeostatic mechanism (e.g. elderly, children, chronically ill, addicted, obese, those w/o AC).
heat stroke: PE
rectal temp, anhydrosis is not a criteria for Dx, may have wet lungs 2/2 vascular endothelial dysfxn
heat stroke: labs
ABG/CXR to r/o ARDS, CBC/coags to assess DIC, may see leukocytosis 20-30K w/thrombocytopenia, UA to screen for ARF/rhabdo, elevated AG from LA, elevated LFTs (almost always, has prognostic sig - AST > 1000 = poor), ECG shows QT + ST prolongation, RBBB, sinus tach, afib, SVT, MI
heat stroke: Tx
aggressive cooling = crucial. options: submerse in ice water, hose w/cold water, ice-soaked towels, wet+windy, iced labage, endovascular cooling, cold hemodialysis, stop cooling when ~39C to avoid overshoot hypothermia
heat-illness pathophys
heat dissipation achieved by evaporation, conduction, convection, and radiation, thermoreg controlled at hypothalamus, ox-phos is uncoupled once > 42C
heat-illness complications
DIC, ARDS, rhabdo, ARF, liver failure, seizures
ED eval: cold
ABG, lytes (BUN may be high, possible hyperK), CBC (may see low WBC, PLT, high Hb/Hct due to hemoconcentration), PT/PTT (can see cold-induced coagulopathy), amylase may be elevated 2/2 cold-induced pancreatitis. CXR may show evidence of aspiration pna or pulmonary edema
hypothermia
hypothermia at core temp < 35C
mild hypothermia
core T 33-35C, shivering and inc. P, RR, BP, CO, ataxia, hyperreflexia, dysarthria, impaired judgment, cold diuresis, bronchorrhea, bronchospasm, dec. GI motility
moderate hypothermia
core T 28-32C, shivering stops, dec. P, RR, CO, CNS depression, hyporeflexia, paradoxical undressing, potential cardiac dysrhythmias (sinus brady, afib w/slow ventricular response, vfib, asystole, can see osborn J waves, pt is sensitive to movement and jostling can precipitate vfib
severe hypothermia
core T <28C, pulmonary edema, oliguria, loss of reflexes (patellar is last to go), hypotension, acidosis, coma, vfib, asystole
hypothermia mgmt
minimize further heat loss, ABCs, lay person flat to minimize hypotension, give IVF, give glucose, avoid caffeine, watch for hyperK, rewarm faster (>2C/hr) if unstable. 1-2C/hr if stable.
frostnip
mild cold injury, reversible
pernio/chillblains
chronic vasculitis resulting from repeated exposures, see red/purple macules/papules/plaques/nodules, often on feet
trenchfoot
aka immersion foot, characterized by redness/swelling/throbbing pain/ulcers, can occur at temps up to 60F if feet are constantly wet
surfer’s ear
exostosis of bone in ear canal
frostbite
frozen tissue, smokers, people w/prolonged arm/hand vibration, and people w/vascular dz are at increased risk
frostbite mgmt
rewarm w/water 40-42C, analgesia, leave blood-filled blisters alone, drain clear blisters, aloe vera to affected area, tetanus prophylaxis (if not current)
