Environmental Emergencies Flashcards
Definition and classification of Hypothermia
Def: core temp = 95F
Mild: 89.6-95F (32-35C)
Mod: 86-89.6F (30-32C)
Severe: <86F(<30C)
Conduction
Transfer of heat by direct contact (water immersion)
Convection
Transfer of heat by movement of heated material (wind disrupting heat around body)
Radiation
electromagnetic transmission
evaporation
conversion of liquid to vapor - usually accounts for 10-15% heat loss (sweat, resp processes)
Etiology of hypothermia
medical illness (DM, PVD, ASVD, Neuropathy, Psych)
Ethanol (MCC)
wind chill
clothing
smoking
homeless
High risk pt for hypothermia and MC
age extremes, altered sensorsium
MC: males 30-49 y.o; extremities
Pathophys of hypothermia
Initially have increased HR, vasoconstrict + incr O2 consumption but decrHR after 32C
Hypoventilation w/ CO2 retention (=hypoxia, rest acid)
Decreased mucocillaiary clearance (incr secretions, dear gag/cough = incr aspiration)
Slowed mentation, motor, speed of reasoning
dear plt fan 2/2 sequester in portal system (= incr blood viscos + thrombi)
Decr. colga factor activity
cold diuresis
imp. insulin release
shift Oxyhemo curve to Left (harder to unload)
Hypothermia: what happens after trx started
cold, acidotic peripheral blood returns to central circ = temp decr. further and incr. risk for arrhythmia
Hypothermia: 3 main priority organs
brain, heart, kidney
hypothermia: clinical abnormalities
shivering stops @ 90 (32.2C)
incr. arrhythmias @ <86(30): Osborn J wave
w/hold card meds and defib until temp >82.4F (28C)
Hypothermia: common EKG signs
Osborn J-wave; no bunnies in v1/v2, but +in v3
Hypothermia: trx
warms O2 vent + warmed IV fluids
Active external rewarm (blankets) 1 deg C/hr
Gently circulating water (104-107.6F, 40-42C)
Active core rewarm (incr 2 deg/hr) = 2 cutes tubes each side w/ warm fluid in top, out bottom; warm NGT/urinary catheter + IVF
Frostbite Pathophys
- Cold Exposure
- Formation of extra cell ice crystals damaging cell membranes and osmotic gradient
- Intracell dehydration
- intracell ice crystal formation
- Cell death
Frost bite classifications
first deg: anesthetic central white plaque w/ peripheral erythema
2nd deg: clear or milky-filled blisters surrounded by erythema and edema
3rd deg: hemorrhagic blisters that progress to hard black eschar
4th degree: complete necrosis and tissue loss
Frostbite Treatment
- elevate and splint extremity
- wrap in dry gauze
- debride white/clear blisters
- aloe vera q 6 hr
- tetanus
- analgesics (ASA, NSAIDS, narc)
- Abx no role
- no smoke
UV Keratitis
-snowstorm/flare on slit lamp
damage to anterior chamber of eye
-develop w/in 1 hr of exposure; no symp until 6-12hrs
-severe pain, foreign body sensation, tearing, conjunctival injections
-bad far vision
UV keratitis Trx
- self-limited
- analgesics, cold compress
- cyclogel helps spasm
- polarized sunglasses
- patching not recommended
Heat Injuryies high risk pt
age extremes, confusional states, limited water access, ETOHics, Menta illness, chronic dz
Heat injury: when does radiation occur
when air temp < body temp
What is hyperthermia
a rise in body temp when heat production exceeds heat loss –fever is rise of core body temp in response to circulating cytokines
Heat Injuries Pathophys
-incr endogen heat prod
-decr. heat dispersion
-thirst is poor gauge of hydration status
excerise incr. metabolic rate 20-25x
What meds incr. heat production?
neuroleptics, hallucinogens, amphetamines, anesthetics, LSD, cocaine
What meds inhibit sweating?
Antihistamines, Neuroleptics, TCAs, Atropine, Antispasmodics
how long does acclimation take?
7-10 for adults, 14 for children
Prickly Heat (AKA heat rash)
Acute inflammation of sweat ducts caused by blockage of pores
Pruritic, emaculoppular erythematous rash found over CLOTHED areas of body
Trx: antihistamines, supportive care (cool compress)
Heat Cramps
Painful involuntary spasmodic contractions
usually sweat profusely but replace w/ water only (cramping 2/2 lyte deficit K, Mg)
Treated with rest in cool environment, replacement of fluids and lytes
Heat Exhaustion
Dizzy, weak, malaise, N/V, H/A, myalgias
Syncope orthostasis (drop in 20 from lying to standing), sinus tach (1st treat based on cause), tachypnea
Normal mental status
Treat: rest, volume, lyte replacement
What separates heat exhaustion from heat stroke?
Normal mental status in heat exhaustion; altered in heat stroke
Heat Stroke
MC in summer
TRIAD: hyperthermia (>105F), CNS dyxfxn, Anhydrosis
Seizure, decr. BP, incr HR + RR
Labs: incr. Na/BUN, decr. K, Ca, Phos, Mg
Markedly ELEVATED TRANSAMINASE LEVELS
5% renal failure + rhabdo)
25% ARDS
Heat Stroke treatment
aggressive hydration (IVF @ 250ml/hr w/ foley - monitor UO)
Diagnostics
Reduce temp rapidly to 104F
Remove clothes and apply strategic ice packs (Axilla, neck, groin)
TOC: EVAP COOLING
Diazepam to inhibit shivering
Heat Stroke Poor Prognostic Factors
Delayed rapid cooling AST > 1000 DIC Prolonged coma hypotension Renal Failure in 1st 48 hours
Jellyfish sting
-Pruritic pain, wheals, urticaria
Vinegar used to remove nematocyst (tails); can also use isopropyl alcohol
Topical anesthetics
Oral analgesiscs
No ABX
Stingray or Catfish
Pain, bleed
Irrigation, removal of foreign debris
Hot water immersion (dissolves)
Abx controversial (consider if in dirty water)
Vespids
Yellow jackets, hornets, wasps
sting mx times
bad guys
Apids
honey and bumble bees
barbed stingers
MC allergic rxn 2/2 insect stings
yellow jacket
MCC death from envenomation
Upper airway obstructions
Nest locations
ground = yellow jacket
under leaves/window: wasps
Brushes/lowlying limbs = hornets
Hymenoptera Stings
Local rxn: pain, erythema, edema, pruritus, swelling
Systemic/anaphylactic: majority occur w/in 15 min
-itchy eyes, facial flush, urticaria, dry cough, dyspnea, wheeze, abdominal cramps, N/V/D, Fever, arthralgia
IgE mediated histamine release
Anaphylaxis happens from 2nd exposure
Hymenoptera Stings: Trx
clean wound w/ soap + H2O, remove stinger apply ice pack + elevate Antihistamins epinephrine Steroids Beta Agonists D/c w/ auto-injector of epi (eli-pen)
Brown Recluse Spider
Loxosceles
MC in midwest + south
Wood piles, sheds, garages, closets
Light brown to tan w/ dark violin-shaped mark
Most active enzyme in Brown Recluse Spider Bite
Sphingomyelinase D
Starts dissolving things in skin. Later leads to necrosis
Brown Recluse Spider Bite Si/sx
Mildly erythematous lesion that becomes firm and dry over days-weeks; blush blister then necrosis
F/C, N/V, myalgia, petechia, seizure
Brown recluse spider test and trx
Test: CBC, BMP, Coags, UA; no specific is dx
Trx: supportive, sx once clearly demarcated - wait until wound defines itself
No antivenin available; no benefit for steroids, abs, dapsone, early excision, hyperbaric O2, topical NTG
Black Widow
Lactrodectus
North America (not Alaska)
Attics, barns, sheds, garage, firewood, hay bales
Shiny black w/ red hourglass on abdomen
Black Widow pathophys
Alpha-latrotoxin
Venom releases acetylcholine and norepinephrine @ neurosynaptic junction causes inhibition of reuptake leads to muscle contractions + fatigue
Severe and rigid abdominal pain
Black Widow clinical effects
Hallmark: muscular cramping (abd > chest, back); onset 30-90 min, peaks 3-12 hrs
N/V, diaphoresis, HTN, tachycardia, anxiety, agitation, irritability, weakness, H/A, periorbital edema
Bad: Shock, coma, respiratory failure
Black Widow Trx
No specific test
Narcotics, bentos
Antivenin: 2 vials + NS in 20-30 min (horse serum)
-inidcated for life-threatening HTN/incr HR, rest issues, refractory pain, meds, pregnant, elderly
Ca gluconate, valium as well
Lice
intensely pruritic wheals
waists, shoulders, axillae, neck
Eggs no easily brushed off
Try: lindane (avoid in kids/preggo); fine combing, sterilize clothes + bed
Scabies
Hands/feet between digits
white zigzag threadlike pattern
Trx: elevate/Lindane; calamine; oral antipruritic (ataraxic), analgesics
Snakebites background
8000bites, 5-15death;
90-95% rattlesnakes, copperheads, moccasins
MC time: august - Oct
M>F 9:1
Adults = UE> LE Kids = LE > UE
dry = no venom
Snakes: Red, yellow, black
Red on yellow will kill a fellow; red on black you’ll be fine jack
Snake bites clinical
venom causes local tissue injury, systemic vascular damage, HEMOLYSIS, fibrinolysis, DIC
cardinal features: one/more fang marks, localized pain, etythemia, ecchymoses, progressive edema
N/V, weakness, parenthesis mouth/tongue, METALLIC TASTE, tender lympadenopahty, incr. HR, dizzy, hematuria, Decr. platelets
Snake Bites test + trx
test: CBC, CMP, Coag, UA, T/S
Try: elevate, constriction bands occluding venous outflow ONLY IF DELAY TO CARE, observe x 8 hrs
Admit ALL kids
Cut and suck NOT rec. Extractor devices unproven, Abx NOT rec.
Snake Antivenins
Indicated for worsening swelling, coat abnormalities, systemic effects (hypotensive), all copperhead bites
ACP: 0-5mild, 10-15 mod, 15-20 severe
Polyvalent Immune: 5.2x more potent than ACP; 4-6 initial then repeated 2vials @ 6,12,18hrs
No diff between peds/adults
Scorpions background
found in wood piles, crevices, shoes, clothes
venom activates Na channels = immediate paresthesias, tachycardia, incr. secretions, incr. temp, diaphoresis, SLUDGE (cholinergic)
EYE ROVING
TONGUE FASICULATIONS/DIFF SWALLOW
Scorpion Graes
- local pain +/- paresthesias
- pain remote from site of sting
- CN/Auonomic/somatic dysfxn: blurred vision, roving eye, hyper salivation, tongue fasciculation’s, dysphagia, dystonia; restlessness, involuntary shaking or jerking
- CN/autonomic and somatic nerve dyxfunction
Scorpion Trx
TOC: supportive (cool compress, +/- midazolam)
Anascopr: anitvenom. Supper expensive
Cactus
Pain
Mx foreign bodies
TOC: removal of spines and local wound care
Elmers glue works super well!
Drowning def
process resulting in primary resp impairment from submission/immersion in a liquid medium
Submersion = entire body; immersion = part
Drowning risk factors
Age: 0-4; 15-19
AA, unsupervised bath/pool, bath seat, seizure, ETOH
Drowning Pathophys
- Perceived risk (struggle)
- Last inhalation effort
- Moment of submersion/immersion
- Tissue hypoxia, acidosis, hypercapnia
- Loss of consciousness; involuntary rest. drive - Laryngospasm/aspiration
- Resp failure + death
Water on Sufactant/alveoli
alveolar collapse, shunting, V/Q mismatch
Most victims ingest water during drowning. Vomiting is common and Expected!
Prognostic Factors
Largest: DURATION of submersion and interval time between drowning + ventilation
Good: Age < 14, CPR, CPR < 25min, Detectable pulse on arrivale
Poor: submersion > 5min, no resus > 10, fixed/dilated pupils, GCS < 5, pH < 7.1
Drowning Trx
All victims who require resuscitation should be evaluated in hospital
Asympt observed x 4-6 hrs
Spinal precautions not recommended
O2 if O2 < 92%
Admit x 24 hrs if survive to ER
Thermal burns
2nd MCC accidental death
More freq in <4 or >65
Rule of 9s
Zone of coag = loss
Zone of stasis = salvageable
Zone of hyperemia: hurts
Thermal Burn Degrees
1st: epidermis only; painful, red, no blisters (Sunburn)
2nd part: partially thru dermis, blisters, painful (Hot liquids)
2nd deep: thru hair follicles and sweat glands (steam/oil)
3rd: skin to fat, charred, able, painless, leathery feel
Skin graft: 2nd deep and more
Major Burn criteria
Partial thick > 25% 10-50; >20 outside range full thick > 10; any burn hand/face/feet/perineum any burn crossing amor joint circumferential limb burn inhalational/electrical burn+fractures Burns in infants/elderly
Minor Burn Criteria
<15% 10-50, < 10 outside area
Full thickness < 2%
Thermal Burn Treatment
All get tetanus prophy
NGT
LR x 2 large bore periph IVs
Parkland formula: 4cc/kg/% - 1/2 given in 1st 8 hours, remaining 1/2 over next 18
2-4 in 24, 1/2 in 8 the rest can wait
UrineOP: 0.5-1ml/kg/hr IV narco debride OPEN blisters cover w/ sterile moist dressings w/o abx ointment 24hr f/u after d/c
Thermal Burns Admit criteria
Partial thick >15 or full >5 in 10-50 Part thick >10, full >3 outside range all w/ burn to face, hands, get, perineum, major joint, circumferential electrical, chemical, inhalation burn immunocompromised burns + trauma
Smoke inhalation
3/4 of all fire-related deaths
Suspect: facial/intraoral/pharyngeal burns, singed nasal hairs, soot in mouth/nose, hoarseness, carbonaceous sputum, wheeze
CO pathophys
Binds to hg to form carboxyhemoglobin
affinity for hg 200. > O2 (leftward shift of dissociation curve)
When should you suspect CO poisoning?
Mx family members w/ nonspecific symptoms that resolve in ED
Can pulse ox distinguish hg/carboxyhg, methemoglobin?
no, but pulse CO-OXIMETRY can
CO-Hgb Levels + symptoms
<10% asymptomatic 10-30 = h/a, n/a, loss of dexterity 30-40 = confusion, lethargy, ST seg depress 40-60 = coma >60 = death
Hyperbaric trx indicated?
CO-Hgb > 25-30 cardiac involvement severe acidosis transient or prolonged unconsciousness neuro impriment >36 y.o preggos
cyanide poisoning
MCC = smoke inhalation (house fire)
also in: wool, nylon, acrylics, silk, foam, rubber, plastics; fruits (apricots, bitter almonds, cherries, peaches), cassava root, jewelry/textile industries, Na nitropresside
Cyanide pathophys
Disrupts mitochondrial production of ATP by binding to and inhibiting cytochrome oxidase
Causes cessation or aerobic cellular metabolism
- cellular asphyxiant
- ATP priced via ANAEROBIC pathway which lead to lactate production (>8 strongly suggestive of cyanide poisoning)
Cyanide Symptoms
Mild: H/A, N, vertigo, tachypnea, HTN, AMS
Severe: dyspnea, bradycardia, hypotensive, arrhythmia, unconsciousness, convulsions, CV collapse
Cyanide poison findings
SEVERE metabolic acidosis (2/2 lactate), usually not cyanotic, bitter almond smell
Cyanide Trx
O2
3 parts: Amyl nitrite (oxidizes hero to methe which combos with cyanide to form cyanomethemoglobin)
Sodium nitrite
Sodium thiosulfate
or
Vit B12 (binds with cyanide to for cyanocobalamin - excreted in urine). may cause HTN, chromaturia
Chemical Burns
Acids: Coag, NeCrosis, limits penetration of chem
Alkalis = liquefAction (keeps moving through)
therapy: gentlefolk hydrotherapy
Acetic acid (hair dyes) = local
Overall: Acid > Alkaline
Electrical background
5th leading cause of fatal occupational injury; 2nd leading COD in construction
Most involve low volts
kids < 6 MC w/ cords/sockets
AC more dangerous than DC
AC = lock, DC = thrown back
Order of Resistance to Electricity
Most: bone fat tendon skin muscle blood nerves (least!)
Electrical injuries patho
Cell membrane disruption, edema, coag nec, ischemia, release of myoglobin (renal fail 2/2 rhabdo)
Extent of skin damage no correlate w/ extend of below skin (burn center!)
AC may precipitate V Fib, DC causes systole
Thoracic muscle tetany, direct coronary artery spasm, and myocardial ischemia
Associated injuries with electricity
CP arrest is MC COD (immediate): defib if in V fib
LOC< seizure, amnesia, H/A, weakness
compartment syndrome
Electrical Trx
CBC, CMP, CK, myoglobin
IVF, keep UP >1cc/kg/hr
Myoglobinuria: 1/2amp Na Hco3 to each liter of NS: UO > 1.5 - 2cc/kg/hr
Tetanus prophylaxis
D/c if no evidence of electrothermal injury, normal exam, and EKG; no heme in urine
