Temp Related Emergencies Flashcards
Heat Edema =
seen early in heat exposure, mostly in elderly, increased aldosterone, self-limited
Heat tetany =
results from hyperventilation (paresthesias, carpopedal spasm, tetany 2/2 resp. alkalosis)
self-limited
remove person from heat
Heat rash =
pruritic, erythematous rash on clothing-covered parts of body
Inflammation of obstructed sweat glands
Tx w/ antihistamines, avoid heat, light/loose clothing
Heat syncope =
early in heat exposure
combo of vasodilation + decreased vasomotor tone + mild dehydration
tx in cool enviro w/ rehydration
check for injuries and other syncope causes, esp. in elderly patients
Heat cramps =
seen when cooling muscles off
likely 2/2 hypoNa/hypoCl from water w/out electrolytes
needs salt + fluids
may be predisposed to malignant hyperthermia
Heat exhaustion:
excessive water/salt loss
generally develops over days
non-specific symptoms (HA, N/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:
altered MS w/ core temp > 40.5C (105F)
peripheral cooling precedes central cooling so temp may be a bit lower
seen often in patients w/ compromised homeostatic mechanism (i.e., elderly, small children, chronically ill/addicted, obese, those w/out AC)
Diagnostic tests for heat stroke:
Exam
Labs
Exam findings in heat stroke:
temperature should be measured rectally
anyhydrosis not a criterion for diagnosing heat stroke
may have wet lungs 2/2 vascular endothelial dysfxn
Lab results for heat stroke:
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 lactic acidosis
elevated LFTs in almost all cases (carry prognostic significance, AST > 1000 = poor)
ECG findings in heat stroke:
QT and ST prolongation
RBBB
sinus tach
atrial fibrillation
SVT
evidence of MI
Treament of Heat stroke:
- aggressive cooling is crucial:
- options =
- submerse in ice water
- hose w/ cold water
- ice-soaked towels
- wet+windy
- iced lavage
- endovascular cooling
- Cold hemodialysis
- stop cooling when ~39C to avoid overshoot hypothermia
- options =
Pathophysiology of heat-related illnesses:
Heat dissipation achieved by evaporation, conduction, convection, and radiation
thermoregulation controlled at hypothalamus
Ox-Phos is uncoupled once > 42C
Major complications of heat related illness include:
DIC
ARDS
Rhabdomyolysis
ARF
liver failure
Seizures
Components of ED Evaluation for Cold-Related illnesses:
- ABG, electrolytes
- BUN may be elevated, possible hyperK
- CBC
- may see decreased WBC and PLT
- Increased 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
Define Hypothermia and its classes =
hypothermia at core temperature < 35C
mild (33-35C)
moderate (28-32C)
severe (<28C)
Signs and Sx of Mild Hypothermia
- shivering and increased pulse/RR/BP/CO
- ataxia
- hyperreflexia
- dysarthria
- impaired judgment
- cold diuresis
- bronchorrhea
- bronchospasm
- decreased GI motility
Signs and sx of moderate hypothermia
- shivering stops
- decrased pulse/RR/CO
- CNS depression
- hyporeflexia
- paradoxical undressing
- potential cardiac dysrhythmmias (sinus, brady, atrial fib w/ slow ventricular response, VFib, asystole)
- can see Osborn J wave
- patient is sensitive to movement and jostling can precipitate VFib
Signs and sx of severe hypothermia:
pulmonary edema
oliguria
loss of reflexes (patellar last to go)
hypotension
acidosis
coma
VFib
asystole
Management of hypothermia:
Rate of rewarming in stable vs unstable ptns
minimize further heat loss + ABCs
Lay person flat to avoid worsening hypotension
Likely volume depleted (give IVF)Give glucose, but avoid caffeine
Watch for hyper K
Hemodynamically unstable patients should be rewarmed faster (>2C/hour), if stable just @ 1-2C/hour
Frostnip =
mild case of cold injury, reversible
Pernio/chilblains =
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, seen in cold water surfers
Frostbite
Describe:
frozen tissue
smokers, people w/ prolonged arm/hand vibration, and people w/ vascular disease are at increased risk
Management of frostbite
rewarm w/ water 40-42C
analgesia
leave blood-filled blisters alone
drain clear blisters
aloe vera to affected area
tetanus prophylaxis if not current
