environmental emergencies Flashcards
define hypothermia
core temperature 95 or less
classify hypothermia based on mild-mod-sev
mild: 89.6-95
mod: 96.98.5
severe: less than 86
define conduction
transfer of heat by direct contact (water immersion)
define convection
transfer of heat by movement of heated material (wind disrupting heat around body)
define radiation
uses electromagnetic transmission
define evaporation
conversion of liquid to vapor (10-15% body heat loss)
what is the MCC of hypothermia
ethanol
which clothing makes you colder more, wet clothing or not wet?
wet clothing
what medical illnesses are related to hypothermia
DM, PVD, ASVD, neuropathy, and psychiatric illness
which group is the MC affected by hypothermia?
males 30-49 y/o and extremities
what is the pathophysiology of hypothermia?
decreased HR
hypoventilation with CO2 retention leading to hypoxia and respiratory acidosis
Decreased mucocillary clearance
Slowed mentation, motor function, and speed of reasoning
Decreased platelet function
Decreased activity of coagulation factors
Cold diuresis
Impaired insulin release
After-drop occurs
when does shivering cease?
90F
what occurs at 86F or less (hypothermia)
increased arrhythmias (osborn J waves)
when should you withhold cardiac meds and defibrillation
until temp 82.4F or greater
how do you treat hypothermia?
warmed oxygen and IV fluids (NS)
active external warming (blankets)
gently circulating water
active core warming
what is the pathophysiology of frost bite
cold exposure formation of extracellular ice crystals which damage cell membranes and their osmotic gradient intracellular dehydration intracellular ice crystal formation cell death
anesthetic central white plaque with peripheral erythema
first degree frostbite
clear or milky-filled blisters surrounded by erythema and edema
second degree frostbite
hemorrhagic blisters that progress to a hard black eschar
third degree frostbite
complete necrosis and tissue loss
fourth degree frostbite
how to treat frostbite?
elevate and splint extremity wrap extremity in dry sterile gauze debride white or clear blisters cover with aloe vera every 6 hours tetanus as indicated analgesics (ASA/NSAIDS, narcotics) antibiotics have no role no smoking
ultraviolet keratitis can develop within ____ hour of exposure
1 hour
how does UV keratitis present?
does not become symptomatic until 6-12 hours later
severe pain, FB sensation, tearing, conjunctival injection
how do you treat UV keratitis
self-limited
analgesics, cold compress
polarized sunglasses
which pts are at risk of heat injuries?
age extremes confusional states limited water access alcoholics mental illness chronic disease
define radiation in regards to heat injuries
occurs when air temp is less than body temp
define hyperthermia
rise in body temperature when heat production exceeds heat loss - fever is rise of core body temp in response to circulating cytokines
what is the pathophysiology of heat injuries?
increased endogenous heat production
decreased heat dispersion
thirst is poor gauge of hydration status
exercise increases metabolic rate 20-25 times above baseline
which meds increase heat production?
neuroleptics hallucinogens amphetamines anesthetics LSD cocaine
which meds inhibit sweating?
antihistamines neuroleptics TCAs atropine antispasmodics
what is the duration of acclimatization of heat injuries for adults/children?
7-10 days for adults
14 days for children
define prickly heat aka heat rash
acute inflammation of sweat ducts caused by blockage of pores
pruritic, maculopapular erythematous rash found over clothed areas of body
how do you treat prickly heat aka heat rash
antihistamines
supportive care
define heat cramps
painful involuntary spasmodic contractions
usually sweat profusely but replace with water only
how do you treat heat cramps
rest in cool environment
replacement of fluids and electrolytes
what is the presentation of heat exhaustion
dizzy, weak, malaise, N/V, headache, myalgias
syncope, orthostasis, sinus tach, tachpnea
normal mental status
how do you treat heat exhaustion?
rest and volume/electrolyte replacement (Do Mg first before fixing K)
what is the triad of heat stroke
hyperthermia (105F or more)
CNS dysfunction
anhydrosis (not sweating)
UV keratitis causes
sun reflecting on water/snow
welding
how does heat stroke present?
seizure, decreased BP, increased HR, increased RR
increased Na and BUN
Decreased K, Ca, Phos, Mg
Elevated Transaminate levels
5% develop renal failure (rhabdomyolysis)
25% develop ARDS
how to treat Heat stroke?
IV fluids at 250cc/hr with foley to monitor UO
Diagnostics
Reduce temp rapidly to 104F
Remove clothing apply “strategic ice packs”
TOC = evaporative cooling
Diazepam 0.1-0.3 mg/kg to inhibit shivering
What are poor heat stroke prognostic factors?
delayed rapid cooling AST 1000 or greater DIC prolonged coma hypotension renal failure in first 48 hours
How does jellyfish envenomation present?
pruritic pain, wheals, urticaria
how do you treat jellyfish envenomations?
vinegar to remove nematocyst (isopropyl alcohol)
topical anesthetics
oral analgesics
no ABX
how do stingray/catfish envenomations present?
pain, bleeding
how do you treat stingray envenomation?
irrigation, removal of foreign debris
hot water immersion
ABX controversial
what are vespids
yellow jackets, hornets, wasps that sting multiple times
what are apids
honey and bumblebees that are barbed stingers
what is the MCCC of allergic reaction secondary to insect stings
yellow jacket
what is the MCC of death from envenomation?
hymenoptera stings usually from upper airway obstruction
where are the nest locations of yellow jackets?
ground
where are the nest locations of wasps?
under leaves or window sills
where are the nest locations of hornets?
bushes, low-lying limbs
how does a local reaction of hymenoptera sting present?
pain, erythema, edema, pruritis, and swelling
how do systemic/anaphylactic reactions of hymenoptera stings present?
occur within 15 minutes
itchy eyes, facial flushing, urticaria, dry cough, dyspnea, wheezing, abdominal cramps, N/V/D, fever, arthralgias
IgE mediated histamine release
how to treat hymenoptera stings?
clean with soap and water, remove stinger apply ice pack and elevate extremity antihistamines - benadryl epinephrine steroids beta agonists D/C with auto-injector of epinephrine
brown recluse spider bites are MC where
midwestern and southern us
where are brown recluse spiders hiding
woodpiles
sheds
garages
closets
what is the most active enzyme of brown recluse spider
sphingomyelinase D
how do brown recluse spider bites progress
mildly erythematous lesion that becomes firm and dry over days to weeks and becomes bluish blister then necrosis
what are symptoms of brown recluse spider bites?
F/C N/V myalgias petechia seizure
what tests do you order for brown recluse spider bites
CBC
BMP
Coags
UA
how to treat brown recluse spider bites?
supportive
no antivenin available
surgery once clearly demarcated
no proven benefit for steroids, ABX, dapsone, early excision, hyperbaric oxygen, topical NTG
what is another name for brown recluse spider
loxosceles
what is another name for black widow spider
latrodectus
where are black widow spiders located?
North America except Alaska
where do black widow spiders hide?
attics, barns, sheds, garage, firewood, and hay bales
what do black widow spiders look like?
shiny black with red hourglass on abdomen
what do brown recluse spider look like?
light brown to tan in color with dark violin-shaped mark on dorsal cephalothorax
what is the pathophysiology of black widow spider bites?
alpha-latratoxin
venom releases acetylcholine and NE at neurosynaptic junction
inhibits their reuptake
muscle contractions and fatigue
what is the hallmark of envenomation in black widow spider bites
muscular cramping (abdomen > chest, back); onset 30-90 minutes post-bite and peaks in 3-12 hours
what are other symptoms of black widow spider bites?
N/V, diaphoresis, HTN, tachycardia, anxiety, agitation, irritability, weakness, H/A, periorbital edema
shock, coma, respiratory failure
how do you treat black widow spider bites?
narcotics
benzodiazepines
antivenin (horse serum) - indicated for life-threatening HTN and increased HR, respiratory difficulty, refractory pain, pediatrics, pregnant, and elderly
Calcium gluconate
how does lice present?
intensely pruritic wheals
waists, shoulders, axillae, neck
eggs not easily brushed off
how to treat lice?
lindane (avoid in young children and pregnant females)
fine combing of hairs
sterilize clothing and bed liners
how do scabies present?
hands and feet between digits
white zigzag threadlike pattern
how do you treat scabies?
elemite or lindane
calamine lotion
oral antipruritic agents (atarax)
analgesics
what are the snakes that make up 90-95% of bites
rattlesnakes
copperheads
moccasins
what is the MC time for snake bites to occur?
August-October
Who is the MC to have a snake bite and where?
Male in his UE
Kids would have in LE
What are the cardinal features of snake vites?
one or more fang marks, localized pain
erythema
ecchymosis
progressive edema
what are S&S of snake bites?
N/V, weakness, paresthesias of mouth and tongue (metallic taste), tender lymphadenopathy, increased HR, dizzy, hematuria, decreased platelets
what tests do you order for snake bites?
CBC, CMP, Coags, UA, T/S
How to treat snake bites?
elevate extremity constriction bands ABX not indicated Observe for at least 8 hours, if asymptomatic, D/C admit all children with bites Peds treated same as adults
When are antivenins indicated for snake bites?
worsening swelling, coagulation abnormalities (decreased platelets, PT > 20 seconds), systemic effects (hypotension), all copperhead bites
what are examples of antivenins
antivenin crotolidea polyvalent (ACP)
polyvalent immune fab (CroFab, FabAV) - 5.2 times more potent than ACP
what is the name for scropions
centruroides excilicauda (bark scorpion)
where do you find scorpions?
wood piles, crevices, shoes, clothing
what is the pathophysiology of scorpions?
venom activates sodium channels which causes immediate paresthesias, tachycardia, increased secretions, increased temperature, diaphoresis, and SLUDGE
how do scorpion stings present?
pathognomonic roving eye movements
fasciculations
difficulty swallowing
scorpion envenomation grade 1
local pain and/or paresthesias
scorpion envenomation grade 2
pain and/or paresthesias remote from site of sting
scorpion envenomation grade 3
CN/automatic or somatic dysfunction
blurred vision, roving eye movements, hypersalivation, tongue fasiculations, dysphagia, dysponia
restlessness, involuntary shaking or jerking
scorpion envenomation grade 4
CN/autonomic and somatic nerve dysfunction
what is the treatment of choice for scorpions?
supportive
cool compress
+/- midazolam continuous infusion
What is anascrop
centruroides immune Fab Equine injection for scorpion sting
how does one present with cactus sting?
pain and potential for multiple foreign bodies
how can you remove cactus FB?
Elmer’s glue
how do you treat cactus sting?
all that is required is removal of spines and local wound care
define drowning
process resulting in primary respiratory impairment from submersion/immersion in a liquid medium
define submersion
entire body is covered in liquid medium
define immersion
oral and nasal airways are covered in liquid medium
which group of people is drowning the MCC of death?
children 1-18 y/o
what are RF for drowning
african americans unsupervised bath/pool time bath seat use seizure alcohol use
what is the pathophysiology of drowning
struggle last inhalation effort moment of submersion or immersion tissue hypoxia, acidosis, hypercapnia larygnospasm or aspiration respiratory failure and death
how much water per kg can compromise surfactant in the alveoli
1-3 mL/kg
what is common during the drowning process?
vomiting
what are good prognostic factors of drowning
age < 14 y/o
CPR in the filed
CPR < 25 minutes
detectable pulses on arrival
what are poor prognostic factors of drowning
submersion > 5 minutes no resuscitation for > 10 minutes fixed and dilated pupils GCS < 5 pH < 7.1
which type of drowning victims should go to hospital?
all victims of drowning who required any form of resuscitation
how long should asymptomatic drowning victims be in hospital?
observed 4-6 hours post event
how to treat drowning?
Oxygen if SaO2 < 92%
if survive to ER, then admit for at least 24 hours
what is the second MCC of accidental death in US
thermal burns
what are the zones of thermal burns?
zone of coagulation
zone of stasis
zone of hyperemia or inflammation
what are the rule of nines for thermal burns
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
how does a first degree thermal burn present
epidermis only - painful, red, no blisters - sunburn
how does a second, degree, partial thermal burn present
partly through dermis - blisters, painful - hot liquids
how does a second degree, deep thermal burn present?
thru hair follicles and sweat glands - hot steam or oil
how does a third degree thermal burn present?
skin to fat - charred, pale, painless, leatherly feel
what are the major burn criteria
partial thickness 25% or more, BSA in 10-50 y/o, 20% or more if 10 year olds or less or 50 year olds or more full thickness 10% or more in anyone any burn to hands, face, feet, perineum any burn crossing major point circumferential limb burn inhalational or electrical injury burn with fractures burns in infants and elderly
what is minor burn criteria
<15% or less BSA in 10-50 y/o
<10% 10 y/o or less or 50 y/o or older
full thickness 2% or less BSA
how to treat thermal burns?
all get tetanus prophylaxis regardless of current status
NG tube
LR via 2 large bore peripheral IV’s
Keep UO 0.5-1.0cc/kg/hr for adult and 1.0cc/kg/hr for children
IV narcotics
sharply debride open blisters
cover with sterile moist dressings without ABX ointment if pt to be transferred
If D/C’ed, need 24 hour follow up
what is the parkland formula?
4cc/kg/%BSA
1/2 given in first 8 hours postburn
remaining 1/2 over next 18 hours
what is thermal burn admission criteria?
partial thickness 15% or more and full thickness 5% or more in 10-50 y/o
partial thickness 10% or more and full thickness 3% or more in 10 y/o or less and 50 y/o or greater
anyone with partial or full thickness burn to face, hands, feet, perineum, across major joint, circumferential limb burn
any electrical, chemical, inhalational burn
immunocompromised
burns with trauma (fractures)
3/4 of all fire related deaths are due to this
smoke inhalation (CO and/or cyanide poisoning)
suspect smoke inhalation if
facial, intraoral, or pharyngeal burns singed nasal hairs soot in mouth or nose hoarseness carbonaceous sputum wheezing
what is smoke inhalation pathophysiology
CO binds to Hgb to form carboxyhemoglobin
CO has affinity for Hgb that is 200x that of oxygen
Causes leftward shift of the Hgb oxygen dissociation curve
when should you suspect CO poisoning
if you have multiple family members with nonspecific symptoms, which resolve in the ED
what are normal CO-Hgb values
normal 2-5%
what are CO-Hgb values for msokers
higher 5-13%
Based on CO-Hgb levels, what are the symptoms
<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 treatment indicated?
CO-Hgb > 25-30% Cardiac involvement severe acidosis transient or prolonged unconsciousness neurological impairment age > 36 y/o pregnancy
what is the MCC of cyanide poisoning
smoke inhalation
what products would have cyanide released after burning
wool nylon acrylics foam rubber silk plastics cassava root jewelry and textile industries sodium nitroprusside
which fruit pits containing amygdalin related to cyanide
apricots
bitter almonds
cherries
peaches
what is cyanide pathophysiology
cyanide disrupts mitochondrial production of ATP by binding to and inhibiting cytochrome oxidase
causes cessation of aerobic cellular metabolism
cellular asphyxiant
ATP produced via anerobic pathway which leads to lactate production
what lab suggests cyanide poisoning
lactate > 8
what are mild cyanide symptoms
H/A nausea vertigo tachypnea HTN AMS
what are severe cyanide symptoms
dyspnea bradycardia hypotension arrhythmia unconsciousness convulsions CV collapse
what are cyanide poisoning findings
severe metabolic acidosis
usually are not cyanotic
smells like bitter almonds
how do you treat cyanide poisoning?
oxygen amyl nitrite sodium nitrite sodium thiosulfate hydroxycobalamin (vitamin B12) - causes transient HTN, chromaturia
define chemical burns
acids cause coagulation necrosis which limits penetration of chemical
alkalis causes liquefaction necrosis
what is the cornerstone of therapy for chemical burns?
hydrotherapy (gentle flow not high pressure)
what chemical is found in hair dyes?
acetic acid
what is the 5th leading cause of fatal occupational injury and 2nd leading cause of death in construction industry?
electrocution
what group of people are most commonly injured with electrical cords and sockets?
children < 6y/o
which parts of body are most resistant to least resistant to electrical injuries?
bone fat tendon skin muscle blood vessels nerves
what is the pathophysiology of electrical injuries?
cell membrane disruption, edema, coagulation necrosis, ischemia, release of myoglobin (renal failure from rhabdomyolysis)
extent of skin damage does not correlate with extend of damage below skin
AC may precipitate V fib
Thoracic muscle tetany, direct coronary artery spasm, and myocardial ischemia
what is the primary cause of immediate death with electrical injuries
cardiopulmonary arrest
what are the symptoms of electrical injuries
LOC, seizure, amnesia, H/A, weakness, compartment syndrome
what labs to obtain for electrical injuries
CBC, CMP, CK, myoglobins
how to treat electrical injuries
IV fluids to keep UO 1 cc/kg/hr or greater
myoglobinuria - amp NaHCO3 to each liter of NS to keep UO 1.5-2cc/kg/hr
tetanus prophylaxis as indicated
how to know when to discharge for electrical injuries?
may d/c if no evidence of electrothermal injury, normal exam and EKG, no heme in urine, if otherwise, admit
where do direct strike lightning occur?
open areas
which lightning strike is the most deadly?
direct strike because person becomes part of the main lightning discharge tunnel
occurs when lightning strikes a taller object near the victim, then a portion of the current jumps from the taller object to the victim; can injure several people at once
side flash
the lightning strike that is most common cause of lightning injuries and deaths to persons/animals
ground current
how does a conduction lightning strike occur
when person is touching an object through which the current is transversing (i.e. wires or other metal surfaces, indoor lighting injuries, electrical outlets, plumbing, water faucets/shower, corded phone, windows, doors)
how do streamers develop?
downward moving leader approaches the ground and is met by an upward moving current
what is the MCC of death with lightening injuries?
cardiac arrest (asytole)
what are symptoms of lightening injuries?
stunned, headache, myalgias, paresthesias, vision and hearing loss (usually gradually resolves)
what is the MC neurological event of lightening injuries?
temporary LOC
pathognomonic fernlike pattern
lightening injuries
what may you develop later in life with lightening injuries?
cataracts
what labs do you check with lightening injuries?
CBC, CMP, CK, EGK, +/- spine or CT brain
how do you treat lightening injuries?
supportive
if survive to ER, admit
do not need aggressive fluids
what is the treatment of choice for any anaphylactic reaction to a bee sting?
epinephrine
what is the pathognomonic physical exam finding in scorpion sting?
roving eye movements
what bite is associated with muscle cramps?
black widow spider
what is the most lethal form of acute mountain illness?
HAPE
