Environmental Emergencies Flashcards
Pathophys of hypothermia?
increased HR, vasoconstriction and increased myocardial oxygen used
hypoventilation with CO2 retention –> hypoxia
decreased mucocillary clearance
slowed mentation, motor func.
decreased platelet func.
In hypothermia, there is a shift of oxyhemoglobin curve to the…
left
When does after drop occur in hypothermia?
when cold, acidotic peripheral blood returns to the central circulation
-reason for initial decreased in temp once begin tx
After drop can increased the risk for…
cardiac arrhythmias
At what temp do we loose our shivering ability? what temp is there an increase in arrhythmias?
90 deg F
<86 deg F : Osborn J wave
We should withhold cardiac meds and defibrillation until temp is…
> 82.4 deg F (>28 deg C)
If you have an Osborn J wave in V3 and V4 on EKG, you should suspect…
hypothermia
Tx for hypothermia?
warmed O2 and IV fluids
active external rewarming- warm blankets
gently circulating water
active core rewarming
If a pt with hypothermia has an arrhythmia then you need to…
rewarm pleura w/ active core rewarming
What is considered hypothermia?
<95 deg F
Classification of hypothermia?
Mild: 89.6-95°F (32-35°C)
Moderate: 86-89.6°F (30-32°C)
Severe:<86°F (<30°C)
Rate of heat transfer with conduction is dependent on…
temperature gradient and size of contact area.
What are the different methods of heat loss?
Conduction, Convection, Radiation, Evaporation
Conduction heat loss?
transfer of heat by direct contact (water immersion)
Convection heat loss?
transfer of heat by movement of heated material (wind disrupting heat around body)
Radiation Heat loss?
uses electromagnetic transmission
Evaporation heat loss?
conversion of liquid to vapor – usually accounts for 10-15% of body heat loss
Pathophys of frost bite?
cold exposure > formation of EC ice crystal which damage cell membrane and their osmotic gradient > IC dehydration > IC ice crystal formation > cell death
1st deg frost bite?
First Degree: anesthetic central white plaque with peripheral erythema
2nd deg frost bite?
clear or milky-filled blisters surrounded by erythema and edema
3rd deg frost bite?
hemorrhagic blisters that progress to a hard black eschar
Don’t drain
4th deg frost bite?
complete necrosis and tissue loss
Tx for frostbite?
elevate and splint extremity
wrap in sterile gauze, debride white/clr blisters
cover with aloe vera
update Tetanus
Analgesics
smoking cessation
Do abx help with frostbite?
NO
How do ASA and NSAIDs help with frost bite?
decrease thromboxane A2 activity
What is keratitis?
inflammation of the anterior chamber of the eye
When can ultraviolet keratitis occur?
corneal burn
w/in 1 hr of exposure
does not become sxs until 6-12 hrs later
Sxs of ultraviolet keratitis?
severe pain, FB sensation, tearing, conjunctival injection
Tx of ultraviolet keratitis?
self limited, analgesics, cold compress, polarized sunglasses
Pts at risk for heat exposure?
Age extremes, confusional states, limited water access, alcoholics, mental illness, chronic diseases
-1/5 of young parents believe it is okay to leave children alone in parked cars
When does radiation occur?
when air temp is less than body temp
What is hyperthermia?
rise in body temp when heat production exceeds heat loss
ex. working out
Fever?
rise of core temp in response to circulating cytokines
pathophys of heat injuries?
increased endogenous heat production, decreased heat dispersion, exercise increased MR 20-25x baseline rate
Is thirst a good gauge of hydration status?
no
What meds can increase heat production?
neuroleptics, hallucinogens, amphetamines, anesthetics, LSD, cocaine
What meds inhibit sweating?
Antihistamines
Atropine
Neuroleptics
Antispasmodics
TCAs
-children also have less effective sweat mechanisms
How long does acclimatization take in adults? children?
7-10days
14 days
What is prickly heat?
heat rash
Acute inflammation of sweat ducts caused by blockage of pores
Pruritic, maculopapular erythematous rash found over clothed areas of body
Tx for prickly heat?
antihistamines, supportive care
Heat cramps?
Painful involuntary spasmodic contractions
Usually sweat profusely but replace with water only
Tx for heat cramps?
rest in cool environment
replace fluids/electrolytes
(fix Mg before K)
Heat exhaustion?
Dizzy, weak, malaise, N/V, Headache, myalgias
Syncope, orthostasis, sinus tach, tachypnea
normal mental status
Tx for heat exhaustion?
rest, volume and electrolyte replacement
Heat stoke?
MC in summer months
Triad = Hyperthermia (> 105°F), CNS dysfunction, Anhydrosis
Seizure, ↓BP, ↑HR, ↑RR
Abnormal labs in heat stroke?
↑ed Na and Bun – ↓ed K, Ca, Phos, Mag (dehydration)
elevated transaminase levels
Tx for heat stroke?
IV fluids
diagnostics
reduce temp rapidly: remove clothes: strategic ice packs
TOC= evaporative cooling
Diazepam to inhibit shivering
Bad prognostic factors for heat stroke?
Delayed rapid cooling
AST > 1000
DIC
Prolonged coma
Hypotension
Renal failure in first 48 hours
Marine Envenomations -Jelly fish?
Pruritic pain, wheals, urticaria
Tx for jellyfish envenomation
vinegar to remove nematocyst
topical anesthetics
oral analgesics
no role for abx
Sxs of stingray envenomation
pain, bleeding
Tx for stingray envenomation?
irrigation, remove foreign debris, hot water immersion
NO abx
Catfish envenomation sxs/tx?
similar to stingray