Flashcards in Environmental Emergencies Deck (134):
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...
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...
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...
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)
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
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
Do abx help with frostbite?
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?
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
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?
What meds can increase heat production?
neuroleptics, hallucinogens, amphetamines, anesthetics, LSD, cocaine
What meds inhibit sweating?
-children also have less effective sweat mechanisms
How long does acclimatization take in adults? children?
What is prickly heat?
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
Painful involuntary spasmodic contractions
Usually sweat profusely but replace with water only
Tx for heat cramps?
rest in cool environment
(fix Mg before K)
Dizzy, weak, malaise, N/V, Headache, myalgias
Syncope, orthostasis, sinus tach, tachypnea
normal mental status
Tx for heat exhaustion?
rest, volume and electrolyte replacement
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?
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
Renal failure in first 48 hours
Marine Envenomations -Jelly fish?
Pruritic pain, wheals, urticaria
Tx for jellyfish envenomation
vinegar to remove nematocyst
no role for abx
Sxs of stingray envenomation
Tx for stingray envenomation?
irrigation, remove foreign debris, hot water immersion
Catfish envenomation sxs/tx?
similar to stingray
Etiology of hypothermia?
Medical illnesses (DM, PVD, ASVD, Neuropathy, Psychiatric illness)
Ethanol (MCC in US)
Clothing (wet vs none)
MCly affects males 30-49 y/o
Hymenoptera Stings, what are the two classes?
Vespids – Yellow Jackets, Hornets, Wasps – sting multiple times
Apids – Honey and bumblebees – barbed stingers
MCC of allergic reaction secondary to insect stings = Yellow jacket
What is the MCC of death from envenomation for hymenoptera stings?
upper airway obstruction
Nest locations for bugs?
Ground – Yellow jacket
Under leaves or windowsill – Wasps
Bushes, low-lying limbs - Hornets
Sxs of Hymenoptera stings?
Local reaction – Pain, erythema, edema, pruritis, swelling
Systemic/anaphylactic rxn: most within 15 minutes:
Itchy eyes, facial flushing, urticaria, dry cough, dyspnea, wheezing, abdominal cramps, n/v/d, fever, arthralgias. IgE mediated histamine release
Hymenoptera stings tx?
clean with soap/water, remove stinger
antihistamines (Benadryl + type 2 i.e. Pepcid)
DC w/ auto injector epi
If you give a pt with a rash epi and it goes away...
you know its an allergic rxn
Brown Recluse Spider Bites
MC in Midwestern and southern US
Woodpiles, sheds, garages, closets
Brown Recluse Spider Bites active enzyme? sxs?
Mildly erythematous lesion that becomes firm and dry over days to weeks Bluish blister then necrosis
+F/C, N/V, myalgias, petechia, seizure
Dx Brown Recluse Spider Bites? Tx?
No specific dx. CBC, BMP, Coags, UA
supportive, surg once clearly demarcated
Black Widow Spider Bites
North America except Alaska
Attics, barns, sheds, garage, firewood, hay bales
Shiny black with red hourglass on abdomen
Black Widow Spider Bites pathophys
venom releases acetylcholine and norepinephrine at neurosynaptic junction> inhibits their reuptake > muscle contractions and fatigue
Hallmark of Black Widow Spider Bites? Other sxs?
N/V, diaphoresis, hypertension, tachycardia, anxiety, agitation, irritability, weakness, headache, periorbital edema
HTN 10-30%, shock, coma, res failure
Tx for Black Widow Spider Bites?
Narcodics, Benzos, Antivenin (horse serum)
Ca Gluconate (but doesn't really help)
Intensely pruritic wheals
Waists, shoulders, axillae, neck
Eggs not easily brushed off
Tx for lice?
Lindane (avoid in young children and pregnant females)
fine combing of hair
sterilize clothing/bed linens
Hands and feet between digits
White zigzag threadlike pattern
Tx for scabies?
Elemite or Lindane
Oral antipruritic agents (atarax)
Snake bites epidemiology?
Rattlesnakes, copperheads, moccasins account for 90-95% of bites
MC time for bites is August to October
Male: Female = 9:1
UE >LE for adults, opposite for kids
20-25% Crotaline bites are ...while 60% of coral snakebite are...
dry = no envenomation
Which is poisonous, coral snake or king snake?
Pit viper characteristics?
Pit (heat sensor) between eye and nostril
Elliptical vertically-oriented pupils
What does venom do?
Venom causes local tissue injury, systemic vascular damage, hemolysis, fibrinolysis, and consumption of fibrinogen and platelets
Cardinal features of snake bites? other sxs?
one or more fang marks, localized pain, erythema, ecchymosis, progressive edema
N/V, weakness, paresthesias of mouth and tongue (metallic taste), tender lymphadenopathy, tachycardia, dizzy, hematuria, decreased platelets
Tests for snake bites?
CMC, CMP, Coags, T/S
Tx for snake bites?
constriction bands (occludes venous outflow)
observe for at least 8 hrs
admit all children w/bites
"cut and suck" NOT recommended, NO abx
When are antivenins indicated for snake bites?
worsening swelling, coagulation abnormalities (↓ed platelets, PT > 20 seconds), systemic effects (hypotension), all copperhead bites
Rx: Polyvalent Immune Fab
old: Antivenin Crotolidea Polyvalent
Scorpion sting pathophys
Venom (neurotoxin) activates sodium channels which causes immediate paresthesias, tachycardia, ↑ secretions, ↑ temperature, diaphoresis, SLUDGE
What is pathognomonic for scorpion sting? other common sxs?
roving eye movements
fasciculations, difficultly swallowing
Scorpion envenomation grades?
1 – Local pain and/or paresthesias
2 - Pain and/or paresthesias remote from site of sting
3 – CN/autonomic or
somatic dysfunction: blurred vision, roving eye movements, hypersalivation, tongue fasciculations, shaking/jerking
4 – CN/autonomic and somatic nerve dysfuntion
Tx for scorpion sting?
-3 vials in 10 mins
Tx for cactus spikes?
local wound care
process resulting in primary respiratory impairment from submersion/immersion in a liquid medium
Submersion v. immersion?
entire body covered in liquid medium
part (oral and nasal airways) covered in liquid medium
Risk factors for drowning?
African Americans (except 0-4 y/o), unsupervised pool/bath time, bath seat use, seizure, alcohol use
Pathophys of drowning
percived risk of drowning>
last inhalation effort>
tissue hypoxia, acidosis, hypercapnia>
laryngospasm or aspiration>
-surfactant can be washed out, most victims will ingest water
What determines prognosis of drown?
duration of submersion/immersion
Good: age <14, CPR in field, CPR <25 mins, detectable pulses on arrival
Poor: submersion >5 mins, no resuscitation for > 10 mins, fixed/dilated pupils, GCS <5, ph < 7.1
How long should asxs drowning pts be observed? those who required resuscitation?
eval in hospital
o2 if o2 <92%
admit 24 hrs
postural drainage/heimlich -unproven efficacy
What are the zones of thermal burns?
Zone of coagulation
Zone of stasis
Zone of hyperemia or inflammation
Rule of nines? What is this used for?
Head/neck – 9
Each UE – 9 (9x2)
Each thigh – 9 (9x2)
Each lower leg/foot – 9 (9x2)
Clavicle to pubis – 18
Root of neck thru buttocks – 18
Perineum – 1
ROT = back of hand = 1% BSA
to determine total body area burned
First deg burn
epidermis only – painful, red, no blisters – sunburn
Second deg burn
partial: partly thru dermis – blisters, painful – hot liquids
deep: thru hair follicles and sweat glands – hot steam or oil
Should you drain blister from second deg burn?
Third deg burn
skin to fat – charred, pale, painless, leathery feel
What is included in the major burn criteria?
Partial thickness > 25% BSA in 10-50yo, > 20% if < 10yo or > 50yo,
Full thickness > 10% in anyone,
Any burn to hands, face, feet, perineum
Any burn crossing major joint,
Circumferential limb burn,
Inhalational or electrical injury,
Burn with fractures,
Burns in infants and elderly
Tx for burns
LR via 2 large bore peripheral IVs
"2-4 in 24, 1/2 in 8 the rest can wait"
keep UO 0.5-1cc/kg/hr for adults
sharply debride OPEN blisters
cover with sterile moist dressings w/out abx if transferring
If DC, 24 hr FU
What is more lethal carbon monoxide or cyanide?
CO is more common
When should you suspect smoke inhalation?
Facial, intraoral, or pharyngeal burns,
Singed nasal hairs,
Soot in mouth or nose,
Carbonaceous sputum, Wheezing
CO binds to hgb --> carboxyhemoglobin
CO has affinity for Hgb 200x that of O2 --> leftward shift of hgb oxygen dissociation curve
When should you suspect CO poisoning?
if have multiple family members with nonspecific symptoms, which resolve in the ED
normal CO-Hgb: 2-5%
CO-Hgb level and sxs
< 10% = asymptomatic
10-30% = H/A, N/V, Loss of dexterity
30-40% = Confusion, Lethargy, ST segment depression
40-60% = Coma
>60% = Death
When is hyperbaric tx for CO indicated?
Transient or prolonged
Age >36 years old
cherry red skin is indicative of?
Etiology of cyanide poisoning?
smoke inhalation, byproduct burning (wool, silk), fruit pits containing amygdalin, cassava root, jewelry and textile industries, sodium nitroprusside
Cyanide disrupts mitochondrial production of ATP by binding to and inhibiting cytochrome oxidase --> cessation of aerobic cellular metabolism
Mild: HA, N, vertigo, tachypnea, HTN, AMS
severe: dyspnea, bradycardia, hypotension, arrhythmia, LOC, convulsions, CV collapse
findings for cyanide poisoning?
severe metabolic acidosis, usually not cyanotic, smells like bitter almonds
O2, amyl nitrate, sodium nitrite, sodium thiosulfate
Acid chemical burns causes...
coagulation necrosis which limits penetration of chemical
Alkalis chemical burns cause...
Would you rather get burned by acid or alkalis?
but both suck
Therapy for chemical burns?
In electrical injuries, what is more dangerous alternating current or direct current?
Pathophys of electrical injuries?
Cell membrane disruption, edema, coagulation necrosis, ischemia, release of myoglobin (renal failure from rhabdomyolysis
AC may precipitate V fib
Possible sxs of electrical injuries
cardiopulmonary arrest, LOC, seizure, amnesia, HA, compartment syndrome
Electrical burn tx
CBC, CMP, CK =, myoglobins
What are the dif. ways lightning strike injuries can occur?
side flash/side splash
MCC of death from lightening injuries? sxs?
fatality rate 20-30%
res arrest, "stunned" HA, myalgias, paresthesias, temporary LOC, vision & hearing loss-usually gradually resolves
fern like rash pattern is pathognomonic for
Lightening injuring dx? Tx?
CBC, CMP, CK, EKG +/- or CT braine
Tx: aggressive fluids not needed
if survive to ER, admit
Your neighbor knows you have just completed PA School and comes over to ask you “some medical advice”. He was in the backyard cleaning his storage shed about 45 minutes ago when he was bitten by something. He now complains of severe abdominal pain and nauseous and hypertensive. What most likely bit him?
A. Black widow spider.
B. Brown recluse spider.
C. Granddaddy long leg spider.
What treatment do you suggest to him?
A. Scorpion antivenin.
C. Black widow antivenin.
While climbing Camelback Mountain with your friends, you are bitten by a rattlesnake on the leg. What is the preferred treatment of your injury in the field?
a. Apply tourniquet to the involved extremity.
b. Apply constriction band to the involved extremity.
c. “Cut and Suck” the venom from the wound.
d. Apply warm compresses to the wound
Your friends transport you to the hospital for further evaluation. While in the ED, you are noticed to have progressive swelling of your leg, hypotension, platelet count of 50K, and a PT of 25 seconds. Should you be given antivenin?
What is the treatment of choice for an anaphylactic reaction to a bee sting?
What is the pathognomonic physical exam finding in scorpion sting?
Roving eye movements
58 year old gentleman presents with hypothermia. Core temperature is 85.5°F. Which of the following is the most accurate?
A. Shivering is common
B. Osborne J wave is pathognomic
C. Rough handling can produce dysrhythmias
D. NG tube should be inserted
C + B
Patient presents after being bitten while outside. Bite has target area with muscle cramps. What is the most likely cause?
A. Black widow spider
B. Hobo spider
C. Brown recluse spider
What is the most lethal form of acute mountain illness?