Environmental Flashcards
What are chillblains (pernio), and how do you treat them?
Red/blue edematous plaques from prolonged cold exposure that resolve with supportive care
What is trench foot?
Pale, mottled foot from ischemia d/t prolonged cold exposure.
What is the treatment for trenchfoot?
Supportive
What is Hunter’s response?
Cycles of vasoconstriction and vasodilation when exposed to cold temperature
What is the difference between frostnip and frostbite?
Frostnip does not have crystal formation and is without tissue damage
What causes the damage with frostbite?
Crystal formation breaks down tissue
What is the temperature of the water that should be used to submerse tissue in for treating frostbite?
41-42 C
True or false: dry heat is appropriate for treating frostbite
False
Which type of blisters can be debrided with frostbite?
Clear blisters (maybe)
What is the definition of hypothermia?
Core temp of less than 35 C (95 F)
What is the temp and s/sx that define mild hypothermia?
32-35 C
Excitation phase of increased HR, BP, RR, shivering, confusion
What is the temp and s/sx that define moderate hypothermia?
30-32 C
shivering stops, worsening mental status
What is the goal temp for rewarming in cardiac arrest?
30 C
What is the temp and s/sx that define severe hypothermia?
Less than 30 C
arrhythmias
What are the two mechanisms that cause a cold diuresis?
- Shift of fluid intravascularly
- Loss of enzymatic functions in kidneys
What causes the cold coagulopathy? Why won’t this show up on testing?
- Loss of enzymatic function due to cold
- sampled warmed to standard temp when testing
Why is hyperglycemia common with hypothermia?
Insulin is less effective at lower temperatures
What is passive rewarming, and who is this good for?
Drying and wrapping patient
Good for mild hypothermia
What is active rewarming? What severity of hypothermia is this indicated for?
- Application of exogenous heat (bair hugger)
- Hemodynamically stable pts
What is active invasive warming?
Application of exogenous heat through invasive means
What happens to brain veins with hypobarism?
Dilate
What is the MOA of acetazolamide? Why is this helpful for acute mountain sickness?
Causes HCO3 diuresis, causing you to hyperventilate
At what altitude does acute mountain sickness occur?
Over 2000 m
At what altitude does acute HAPE occur?
Over 3000 m
At what altitude does acute HACE occur?
Over 4500 m
What pharmacotherapy can be used to treat HAPE? (2)
Nifedipine and PDEIs
What pharmacotherapy can be used to treat HACE? (2)
Dexamethasone
Acetazolamide
Why do you never put in earplugs when diving?
Will cause a low pressure chamber, and cause vasogenic edema around that area
What causes barotitis interna? What are the symptoms?
- Bleeding or rupture of the round window due to excessive attempts to equalize pressure
- Vertigo, tinnitus, nystagmus
What causes barodontalgia?
If have crappy fillings with air trapped, when rising from diving causes expansion of gas and pain
What is alternobaric vertigo?
Unequal pressures in each ear causes vertigo
What causes ascent barotrauma?
Holding your breath while surfacing increases the volume in the lungs, and causes an alveoli to rupture
What is the mechanism by which an air gas embolism occurs?
Air bubbles forced into pulmonary veins and into arteries
How fast will an air gas embolism present?
Within 10 minutes of surfacing
Besides using a hyperbaric chamber, what two treatments can help with an air gas embolus?
- Oxygen to minimize ischemia
- IVFs to maximize fluids status
What causes nitrogen narcosis?
Nitrogen under pressure with enter CNS and act like an anesthetic
What is the main problem with oxygen toxicity from diving too deep?
Seizures
What is cutis marmorata?
Patchy rash from dissolution of nitrogen gas in lymphatic tissue from diving
What causes pulmonary edema with heat stroke?
High output HF d/t severe dilitation
At what core temperature should you stop cooling with heat stroke? Why?
- 39 C
- avoid overshoot hypothermia
Why should you spray warm water on patient’s with heat stroke?
Cool water will cause inappropriate shivering
What is the parkland formula?
4kg%burn
True or false: you should decrease the amount of fluids given in a burn resuscitation if they also have an inhalational injury
False
When is time 0 for fluid resuscitation in burn pts?
When the burn occurred, not when they arrive at the ED
How do you get tar off of a tar burn?
Use neosporin and leave on for 24 hours. Will dissolve
2nd degree burns over what body surface area need referral to a burn center
10%
True or false: all 3rd degree burns need to be referred to a burn center
True
Over what volatege is considered “high” voltage?
1000 volts, but over 600 v is when significant damage can occur
Why are electrical burns always less severe superficially?
Skin has higher resistance than underlying tissue
What is the equation for voltage?
I * R
Which is more lethal AC or DC current?
AC
True or false: asymptomatic low voltage shock pts go home without testing
True
How long should high voltage shock pts be monitored for? Does it matter if they’re symptomatic?
12-24 hours, regardless of symptoms
What causes ARDS in drowning?
Washed out surfactant causes alveolar inflammation and non-cardiogenic pulmonary edema
What is the most common metabolic derangement with drowning?
Lactic acidosis
True or false: you should abrade the skin when decontaminating for a radiation exposure
False
An absolute lymphocyte count over what after a radiation exposure portends a good prognosis? An ALC below what is lethal?
1000 at 48 hours
300
What bacteria is associated with human bites?
Eikenella corrodens
What bacteria is found in cat and dog bites?
Pasteurella
What are the s/sx of the delayed beasting rxn? When does this happen, and what causes this?
Serum sickness with nonspecific s/sx, 10-14 days after rxn
What is the dose of epi for anaphylaxis?
0.3-0.5 mg 1:1000 IM
What does the bite of a fire ant look like?
Many tiny pustules
What is the latin name for brown recluse spider? Black widow?
Loxosceles = brown recluse Latrodectus = black widow
Violin spider = ?
Brown recluse
Which spider bites are typically painful, and which are painless: brown recluse vs black widow
Painless = brown recluse Painful = black widow
What does the black widow toxin do physiologically? What are the s/sx?
- Releases NE and ach.
- Causes painful muscle contractions, either systemically or locally as well as localized sweating
What is the treatment for mild and severe cases of black widow spider bites?
- Benzos and analgesics
- Antivenom
What are three snakes make up the crotalid snakes?
- Rattlesnakes
- Copperheads
- cottonmouths
What type of venom do crotalids produce? S/sx?
- Cytotoxic venom
- Local pain, swelling, hemorrhage/coagulopathy
How do you dose crofab?
Treat based on s/sx
How do you treat compartment syndrome from snake bites?
Antivenom is the treatment. Should not have to call surgeon for fasciotomy as the cause is based on toxin
What are the coral snakes?
Red on black snakes
What are the s/sx of coral snakes?
Neurotoxin–bulbar palsies, n/v, paralysis
What is the treatment for jellyfish stings?
vinegar or isopropyl alcohol
What is the treatment for the man of war jellyfish sting?
Saltwater
True or false: freshwater can be used to deactivate jellyfish stings
False–will cause triggering of barbs
Are abx recommended for stingray envenomation?
Yes
What is the treatment for stingray envenomation?
Hot water immersion as toxin is heat labile
What type of toxin do sea snakes have (cytotoxic or neurotoxic)?
Neurotoxic
What is erysipelothrix? What is the treatment?
Fish handler’s cellulitis that looks like erysipelas
-Fluoroquinolones or beta lactams
What is the bacteria that causes fish-tank granuloma? How does this present? Treatment?
- Mycobacterium marinum
- Delayed presentation of granulomas at site of abrasion
- TB drugs
What are the two presentations of vibrio vulnificus? Treatment?
- Necrotizing fasciitis
- Primary septicemia
-3rd gen cephalosporin and doxy
