Environmental Flashcards
general principles of non-freezing cold injuries and 2 examples
non-freezing = occur from wetness at above freezing temps (eg trench foot, chilbains)
presentation of trench foot
feet are initially pale, anesthetic, can be pulseless. after re-warming they change slowly (ie takes 2-3 days), then they become hyperemic with severe burning pain
mgmt of trench foot
supportive, rewarming, keep the dry and bandaged, watch for infection
two meds you can try in chilblains? one topical and one oral
nifedipine PO or topical corticosteroids
in addition to good supportive mgmt
what is pannaliculitis
necrosis of subcutaneous tissue from prolonged exposure to temps just above freezing.
no effective tx, resolves on its own
pathophys of frostbite
arachidonic acid cascade leads to vasoconstriction, platelet aggregation, erythrocyte sludging which leads to thrombosis –> ischemia, necrosis, dry gangrene
when to assess frostbite grade?
after 60 mins of rewarming
frostbite grading
how to re-warm frostbite
water immersion at 37-39 degrees, ideally circulating. try and use heater. do this for 30-60 mins, until extremity is erythematous and pliable
can use warm cloths for face/ears
expect ++ pain and pre-treat
management of frostbite: core treatments and post re-warming pulse deficits
note iloprost and TPA
WMS guideline = aspirate clear blister, leave hemorrhagic blisters alone
which protocol to use for frostbite mgmt in deep frostbite?
yukon protocol (can be googled)
temp that defines hypothermia
core temp under 35
primary vs secondary hypothermia
primary is from cold environment
secondary is from loss of thermoregulation from some other process (eg burns, sepsis, trauma, metabolic etc)
core temp, symptoms, mgmt of hypothermia: stage 1
core temp, symptoms, mgmt of hypothermia: stage 2
core temp, symptoms, mgmt of hypothermia: stage 3
core temp, symptoms, mgmt of hypothermia: stage 4
what is afterdrop in hypothermia?
where core temp continues to drop even after re-warming has begun. pts might cont to get worse, but just need to stick with it.
ECG changes in hypothermia
bradycardia, afib/flutter, long PR, QRS widening, long QTc (kind of hyperK like)
++ osborn J waves (can be misdiagnosed as STEMI)
are afib/flutter pathologic in hypothermia?
not really, they are expected rhythms. myocardium is +++ irritable though, especially below 32 risk of malignant arrhythmia increase .. lower temp = higher risk
where to measure core temp?
if intubated –> esophageal
if not rectal or bladder –> often lag behind true temp
what temp do you need to get up to before terminating a hypothermic code?
core temp > 32
pts in cardiac arrest often have hypothermia, if accurate core temp is > than _____, then cause of arrest was not hypothermia initially
32
rewarming techniques mostly used in stage 2-3 hypothermia
minimally invasive (aka passive external) and active external
can consider active internal in more severe HT, practically only use bladder lavage, but know others for exam