EM E2: Environmental

What workup is needed for CO poisoning?

COHb determination, ABGs, electrolytes, lactate, CBC, EKG, CXR, troponin, serum CK-MB

What are sx of CO poisoning?

dizziness, HA, disorientation, coma, visual disturbances, muscle weakness/cramps, nausea

What is the tx for CO poisoning?

ABCs (normobaric O2 therapy w/ 100% FiO2)

mild → 100% NBO ~4 hrs

major → HBO

What are the nonfreezing types of cold injuries?

Chilblains and Trench foot

What is Chilblains (pernio)?

mild, but comfortable inflammatory lesions of the skin d/t chronic intermittent exposure to nonfreezing cold temperatures

What are sx of Chilblains?

pruritus, burning paresthesia, local edema, erythema, cyanosis, nodules, rarely -ulcers, vesicles, bullae

What is the tx for Chilbains?

supportive → rewarm skin, oral Nifedipine, Pentoxifylline, topical corticosteroids

What is Trench foot?

direct injury to soft tissue sustained from prolonged cooling, accelerated by wet conditions

What are the sx of Trench foot?

tingling, numbness, pale mottled, pulselessness → rewarming = severe burning pain, regain proximal sensation; edema & bullae form, paresthesia

severe: tissue sloughing, gangrene

What is the tx for Trench foot?

prophylaxis; keep warm, ensure boots fit, change wet socks frequently

What are the supportive measures for Trench foot post injury?

maximize efforts to warm, dry, & elevate; oral Pentoxifylline or Limaprost, monitor for infection

What are the freezing cold injuries?

frostnip & frostbite

Which frostbite zone:

most severe usually distal, irreversible

Zone of coagulation

Which frostbite zone:

severe, but possibly reversible, cell damage, tx may have benefit

Zone of stasis

Which frostbite zone:

more superficial, proximal w/ the least cellular damage, generally recover w/o tx in < 10 days

Zone of hyperemia

How does Frostbite typically present?

usually on nose, ears, face, hands, feet or burn pts w/ prolonged ice tx; keratitis if snowmobilers or skiers

How does frostnip present?

superficial freeze injury in the absence of progressive tissue loss, sx resolve on rewarming

What is the tx for Frostbite?

rapid rewarming; aspiration of clear blisters (do NOT drain hemorrhagic ones), cover w/ aloe vera, PCN G

What is hypothermia?

core temp < 95 F resulting from loss of body heat > body heat production

What inc risk of hypothermia?

extremes of age (elderly, neonates); altered sensorium

What are the sx of Hypothermia?

intense shivering → CNS dysfunction, can’t sense cold, lethargy, clumsiness, confusion, hallucinations/coma → resp & HR slow, death

How does hypothermia present on an EKG?

sinus bradycardia, slow afib → V fib or asystole

What happens in mild hypothermia (89.6-95)?

excitation stage → inc HR, CO, BP

What happens once body temp drops below 89.6?

dynamic stage → metabolism slows, shivering stops, CNS declinds, bradycardia, v fib or asystole

What is the tx for hypothermia?

prevent further heat loss (remove wet clothes, wrap in blankets); inc core temp by 1 C/hr

What are supportive measures for hypothermia?

O2 and IV fluids, intubation, glucose if low, warm fluids, thiamine

Who is more susceptible to a heat emergency?

elderly or young, limited mobility, alcoholics, meds (antipsychotics), obesity, dehydration, vigorous exertion

What is the tx for heat syncope?

rehydrate, remove from heat, evaluate for serious dz

What is the tx for heat cramps?

replace fluids (oral or IV), do NOT use salt tablets

What is the tx for heat exhaustion?

NS 1-2 L IV

What are sx of heat exhaustion?

high HCt, Na or BUN; normal neuro, orthostasis, hyperthermia

What is a classic heat stroke?

pts w/ compromised homeostatic system

What is an extertional heat stroke?

healthy pts over do it in hot environment

What are the hallmark sx of heat stroke?

cerebral dysfunction w/ impaired consciousness, high fever, absence of sweating

What is the tx for heat stroke?

O2, NS IV, immediate cooling, AVOID ASA & Tylenol, caution if temp of 102-104 to avoid over-correction

What are sx of sun poisoning?

fever, N/V, HA, severe sunburn w/ vesiculation

What are sx of 1st degree burns?

erythema, pain

What are sx of 2nd degree burns?

blistering, new skin can regenerate, some dermis remains, hel in ~2 wks

What are sx of 3rd degree burns?

painless, slow healing via periphery w/ scarring and contracture, total destruction of dermis/epidermis

What are sx of 4th degree burns?

involves SQ tissue, muscle, fascia, bone

Rule of 9s

review 🙂

What is the tx for burns?

cover w/ dry sterile sheet (if chemical, irrigate surface), IV fluids -requirement must be calculated, transport to burn or trauma center, fiberoptic bronchoscopy may be needed to assess upper airway damage

What type of fluid is most commonly used in US EDs for burns?

Lactated ringers

Parkland formula to calculate fluid requirements in burn pts

4 mL x kg x TBSA = total fluids in first 24 hrs

*give ½ in first 8 hours; ½ in the next 16 hours

Parkland formula: 70 kg pt w/ 40% TBSA

11 L (5.5 in 1st 8 hrs)

What should urine output be in a burn pt?

30-50 mL/kg/hr

How should the burned skin be tx?

remove FB, charred or necrotic skin debrided, leave blisters intact

What topical abx cna be used for partial thickness burns?

Silver sulfadiazine

What is the criteria to admit burn pts?

2/3rd degree > 15%

> 50 yo w/ > 10%

burns to hands, feet, face, perineum

CO poisoning

inadequate support or abuse

severe medical dz (COPD, CAD, DM, renal insufficiency)

What is the burn center criteria?

2/3rd degree > 25%

> 50 yo > 20%

3rd degree: hands, feet, face, perineum

major chemical or electrical burn

respiratory tract injury

major trauma or electrical burn

What should be done for burns causing constricting circumferential eschar?

Escharotomy: medial & lateral incisions to relieve tension

What are the most frequent cause of immediate death d/t electrical injuries or lightening?

cardiac arrhythmias & respiratory arrest

Contact w/ AC current most commonly causes what arrhythmia?

V-fib

Contant w/ DC current causes what arrhythmia?

asystole

What are sx of electrical injuries or lightning strikes?

AMS, coma, paralysis, seizures, resp arrest, cataracts 6 mo-1 yr post exposure

What is the tx for electrical injuries and lightening strikes?

BLS, hydration, clean, debride, and dress burns; massive fluid replacement w/ LR

What injuries can near drowning cause?

hypothermia, panicking, syncope, seizures, spinal cord injuries

What is the tx for a near drowning event?

secure airway, provide O2, IV warmed isotonic fluids, supportive

What is barotrauma of descent?

injury to the TM -may hemorrhage and rupture, sinus barotrauma; rupture of inner ear d/t diving

What is the tx for barotrauma?

immediate otolaryngologic evaluation

What is barotrauma of ascent?

air trapped in middle ear → alternobaric vertigo; air expands in the lungs, may rupture; swallowed air expands causing abd cramps & distension

What causes decompression sickness (DCS) “the bends”?

gas bubble form directly in tissues or circulation obstructing blood flow, leading to ischemia

What is an arterial gas embolism (AGE)?

air enters the left side of the vascular system from pulmonary barotrauma in diving

What are sx of arterial gas embolisms?

variety of stroke sx depending on part of the brain affected, some suffer apnea, cardiac arrest, death or minor defects

What is the tx for DCS and AGE?

administer 100% O2, inc tissue perfusion, IV fluids, HBO

How should pts w/ AGE be positioned?

supine

How should vomiting pts be positioned?

left lateral decubitus

What is the MC fish envenomation?

Stingrays

What are sx of a Stingrays sting?

severe pain -peaks in 30-60, min lasts 48 hrs; weakness, N/V, HA, diaphoresis, syncope, cramps, edema, hypotension, paralysis, arrhythmias, death

What is the tx for Stingray stings?

irrigate, hot water soak x 30-90 min, pain control, XR, abx & Td, no sutures, wound exploration/debridement

What are sx of Sea Urchin stings?

immediate, intense pain, burning pain that evolves into severe muscle aching, erythema & edema near site; synovitis, N/V, paresthesias, paralysis, abd pain, syncope, resp distress

What is the tx for a Sea Urchin sting?

immerse in hot water (113 F x 30-90 min), remove embedded spins, XR, corticosteroids, abx

What are sx of a Portuguese man-of-war sting?

intense pain, burning, throbbing, pruritus, radiates centrally, reddish brown “whiplike” lesions, multiple, linear, very painful, urticarial lesions

Severe: neuro, CV, resp, MSK, GI

What is the tx for a portuguese man-of-war sting?

immediately rinse w/ sea water, 5% Acetic acid (vinegar) will inactivate venom, shave area to remove nematocysts, topic creams, Benadryl or steroids, Td

What are sx of Seabather’s eruption or itch?

vesicular or morbilliform pruritic dermatitis after saltwater, involves covered areas, itching, stinging, or burning, HA, chills, night pruritis

What is the tx for Seabather’s itch?

Benadryl, Calamine lotion, topical steroids

What is the tx for high altitude illness?

descent & O2

What are sx of acute hypoxia?

dizziness, light-headedness, tunnel vision, LOC, unconsciousness

What are sx of Acute mountain sickness (AMS)?

rapid ascent over 6600 ft, insufficient acclimation, HA, N/D, fatigue weakness, pulm edema, dyspnea, cerebral edema, alt consciousness, death

What is the hallmark sx of AMS?

fluid retention, peripheral edema, especially face

In addition to descent & O2 what can be given for acute mountain sickness?

Diamox (acetazolamide) carbonic anhydrase inhibitor -diuretic

*can also give as prophylaxis

What are sx of high altitude pulm edema (HAPE)?

onset w/in 6-36 hr after arrival, incessant dry cough, SOB disproportionate to exertion, HA, fatigue → wheezing, orthopnea, hemoptysis, tachy, rales, patchy infiltrates

What is the tx for HAPE?

rest, semi-Fowler position, 100% O2 mask, immediate descent at least 2000 ft essential, Procardia, Decadron if CNS sx

What are the sx of high altitude cerebral edema (HACE)?

progress neuro deterioration w/ HAPE or AMS, hypoxemia, cerebral edema, ataxia, alt consciousness, coma w/in 12 hrs w/o tx

What is the tx for HACE?

immediate descent at least 2000 ft, O2 mask, Decadron

Which causes more deaths snake bites or bee stings?

bee stings

What snakes are venomous?

Eastern diamondback rattlesnake, Canebreak rattlesnake, Pigmy rattlesnake, Cottonmouth, Copperhead, Coral snake

Does the saying “red on yellow, kill a fellow; red on black, venom lack” work for snakes outside the US?

Nope

What are sx of snake bites?

fang marks, soft pitting edema, bullae, streaking, erythema, contusions, hypotension, petechiae, epistaxis, hemoptysis, paresthesias

What is the tx for snake bites?

identify snake, immobilize limb, Antivenom ASAP = mainstay -give w/in 4-6 hrs, Antivenin polyvalent (equine) or Crofab antivenin polyvalent (ovine)

What should you NOT do in the field for a snake bite?

make an incision over the bite; also do not give antivenin

What is the tx for a snake bite w/ no signs of envenomation?

clean wound, Tdap, observe > 6 hr, consider abx (Augmentin)

What is mild envenomation?

local pain, edema, no systemic signs, normal labs

What is moderate envenomation?

severe local pain; edema >12 in, systemic toxicity, N/V, alt lab values

What is severe envenomation?

generalized petechiae, ecchymosis, blood-tinged sputum, hypotension, hypoperfusion, renal dysfunction, changes in PT/PTT

What do you need to do before giving antivenom?

intradermal skin test to check for allergic Ron

(+) = wheal > 10 mm diameter

What can antivenom tx be stopped?

edema stops or S&S improve

In addition to antivenom what can be given for a snake bite?

tetanus booster, steroids only for allergic rxn or serum sickness

What are complications of snake bites?

hypotension, coagulopathy, compartment syndrome

What are the 5 P’s of compartment syndrome?

Pain, Pallor, Paresthesia, Paralysis, Pulselessness