Part 1 of a 2 Part Series on Environmental Emergencies

1. Environmental Emergencies I
Nicholas E. Kman, MD FACEP
Associate Professor
The Ohio State University
Department of Emergency Medicine

2. Objectives
 Thermal Injuries
 Burns
 Electrical Injuries
 Lightning Injuries
 Cold Related Injuries
 Hypothermia
 Frost Bite
 Heat Related Illness
 Insect Bites and Stings

3. General Environmental Pearls
 Very young and very old are most at risk
 Due to lack of or loss of protective adaptations
 Underlying disease, medications, poor nutrition
 “Multiple system” injuries
 Most are largely preventable and respond to
common sense treatment
 Increased exposure correlates with increased risk

4. Thermal Injury

5. Statistics
 More than 1 million burn injuries per year in US
 About 45,000 hospitalized (about 4.5% of all
patients)
 18-35 year old age group
 Scald burns: 1-5 year old age group
 4% mortality from major burns
 Increased risk of death: increased burn size,
increased age, presence of inhalational injury,
female sex

6. Burn Zones of Injury
 Gomez, R.; Cancio, LC. “Management of burn wounds in the emergency department.” Emergency Medicine Clinics
Of North America, v. 25 issue 1, 2007, p. 135-46.

7. Burn Zones
 Coagulation – surface tissue necrosis of initial burn
eschar; caused by insult (irreversible)
 Stasis – deep and peripheral to coagulation; cells are
viable but can be further damaged; fibrin deposition,
vasoconstriction, thrombosis (salvageable)
 Hyperemia – peripheral to and below stasis; minimal
cell injury; vasodilatation due to mediators (usually
recovers)

8. Burn Size
 Quantified as body surface area (BSA)
 Rule of nines
 Palm of patient’s hand is approx. 1% BSA
 Lund and Browder burn diagram
- more precise
- age-adjusted

9. Rule of 9’s

10.  Lund and Browder burn diagram
- more precise
- age-adjusted

11. Burn Depth
 Based on need for surgical intervention
 No objective method for measuring depth
 Based on clinical features/judgment
 Burns are dynamic

12. First Degree
 Only epidermal layer
 Skin red, painful and tender without blisters
 Heals in about 7 days
 Symptomatic treatment

13. Second Degree
 Superficial partial-thickness
 Deep partial-thickness

14. Superficial Partial Thickness
 Epidermis and superficial dermis injured
 Skin blistering, moist at blister’s base, painful
 Heals in 14-21 days
 Scarring is minimal

15. Deep Partial Thickness
 Extends deep into dermis, damaging hair follicles,
sweat and sebaceous glands, but deeper parts
survive
 Skin may be blistered, pale white to yellow, absent
pain sensation
 Heals in 3 weeks to 2 months
 Scarring common
 May require surgical debridement or grafting
ATLS

16. Full Thickness-Third Degree
 Entire thickness of skin involved – full thickness
 All epidermal and dermal structures are destroyed
 Skin is charred, pale, painless and leathery
 Will not heal spontaneously
 Surgical repair and grafting are needed

17. Fourth Degree
 Extends through skin into subcutaneous fat, muscle
and even bone
 Devastating, life-threatening
 Amputation or extensive reconstruction needed

18. Inhalational Injury
 Main cause of mortality in the burn patient
 Closed-space fires
 Thermal injury usually limited to upper airway
 Toxic inhalants – carbon monoxide, hydrogen
cyanide
 Damages cells and causes edema of airways
 No single method to demonstrate full extent of injury

19. American Burn Association
 Classification of burns – major, moderate and minor
 Burn unit referral criteria

20. ABA Burn Unit Referral
 Partial-thickness burns >10% total body surface
area (BSA)
 Burns that involve face, hand, feet, genitalia,
perineum or major joints
 Third-degree burns in any age group
 Electrical burns, including lightning injury
 Chemical burns
 Inhalation injury
 Source: American Burn Association

21. ABA Burn Unit Referral
 Burns with preexisting medical disorders that
complicate management, prolong recovery or
affect mortality
 Patients with burns and concomitant trauma
(such as fractures) in which burn injury poses
greatest risk of morbidity or mortality
 Burned children in hospitals without qualified
personnel or equipment for peds
 Burn patients requiring special social, emotional
or long-term rehabilitative intervention
 Source: American Burn Association

22. Treatment
 Airway with c-spine immobilization
 For facial burn, singed nasal hair, soot in mouth-
 Early intubation
 100% O2
 COHgb level

23. Fluid Resuscitation
 Parkland formula: 4 ml x wt (kg) x % BSA
 ½ over 1st 8 hrs. from time of burn
 Other ½ over the subsequent 16 hrs.
 Second- and third-degree burns only
 Children – 3 ml x wt (kg) x % BSA + MNT
 Lactated ringers
 Check perfusion – Urine OP, HR, BP

24. Burn Zones and Resuscitation
 Hettiaratchy, S.; Dziewulski, P. “ABC of burns: pathophysiology and types of burns.” BMJ: British
Medical Journal, v. 328 issue 7453, 2004, p. 1427-9.

25. Secondary Assessment
 Head to toe assessment
 Check for corneal burns of eyes
 Calculate BSA
 NG tube, foley for more than 20% BSA
burns

26. Diagnostic Studies
 CBC, BUN, Cr, glucose
 Blood gas
 UA – myoglobin
 CXR – inhalational injury
 ECG – electrical injury

27. Special Considerations
 Electrical injuries, incineration burns and crush
injuries may produce rhabdomyolysis and
myoglobinuria – acute renal failure
 Thermal injury + multi-system trauma – will have
greater fluid needs than calculated
 Those with preexisting pulmonary or cardiac disease
need much greater attention to fluid management

28. Quiz
 A 52 year old male is rescued from a burning
building. He has blistering to his chest,
carbonaceous sputum, a hoarse voice, and
circumferential burns to the right arm. What is the
primary treatment priority?
 A. Escharotomies of the R arm
 B. Silvadene to the chest
 C. Cyanide treatment
 D. Airway management

29. Quiz
 A 52 year old male is rescued from a burning
building. He has blistering to his chest,
carbonaceous sputum, a hoarse voice, and
circumferential burns to the right arm. What is the
primary treatment priority?
 A. Escharotomies of the R arm
 B. Silvadene to the chest
 C. Cyanide treatment
 D. Airway management

30. Electrical Injuries
 1000 - 1300/year in U.S.
 25% lightning (30% mortality)
 15% overall mortality
 High-risk groups
 Electricians/builders
 Industry
 Toddlers

31. Electrical Injuries Pearls
 Longer duration=worse injury (except with lightning).
 Effects are usually worse with AC than DC at the
same voltage (flexor tetany, victim locks up to
charge)
 High-voltage electrical injuries (>1000V) are at
increased risk for spinal injury (immobilize!)

32. Electrical Injuries Pearls
 Look for entrance and exit wounds (bull’s eye with
charred center)
 Treat myoglobinuria
 Admit high voltage burns and symptomatic low
voltage exposures
 If EKG changes or LOC, 24 hours of monitoring is
indicated.

34. Lightning Injuries Pearls
 “Resuscitate the dead”-Reverse Triage
 Massive fluid resuscitation seldom necessary
 Think about this in confused patient or unconscious
patient with no shoes/clothes
 Entrance or exit wounds are rare, but look for
Lichtenberg figure

35. Burn General Wound Care
 Clean with mild soap/water or dilute antiseptic
 Leave blisters intact unless over joint
 Debride broken blisters
 Anti-microbials
 Change dressing twice daily while weeping
 Daily dressing change thereafter
 Re-evaluate in 24 hours

36. Anti-Microbials
 Reduce bacterial colonization
 Enhance rate of healing
 Silver sulfadiazine 1%: easy, not on face
 Triple-antibiotic: face, small areas
 Aquacel: occlusive dressing with silver, left in place
until separation occurs
 Mepilex Ag: newer dressing

37. Other Care
 Tetanus prophylaxis
 Pain control
 For transfer – dry sterile dressings
for large burns; moist, saline-soaked
dressings for small areas only
 Circumferential burns – may need
escharotomy
http://lifeinthefastlane.com/trauma-tribulation-005/

38. Quiz
 A 30 year-old male is struck by lightning and is
pulseless and apneic. Which is correct?
 a. CPR is not necessary as his heart will start
beating on its own
 b. CPR is not helpful as his heart likely sustained
irreversible damage
 c. CPR should be initiated and continued until he
begins breathing on his own, then you may stop
 d. CPR should not be initiated as the patient may
have a residual charge from the lightning

39. Quiz
 A 30 year-old male is struck by lightning and is
pulseless and apneic. Which is correct?
 a. CPR is not necessary as his heart will start
beating on its own
 b. CPR is not helpful as his heart likely sustained
irreversible damage
 c. CPR should be initiated and continued until he
begins breathing on his own, then you may stop
 d. CPR should not be initiated as the patient may
have a residual charge from the lightning

40. Hypothermia and Frostbite

41. 41
Brown DJ, Brugger H, Boyd J, Paal P. Accidental hypothermia. N Engl J Med.
2012;367(20):1930-8.

42. Hypothermia
 Yearly, about 1500 patients in US have hypothermia
noted on their death certificate.
 Exact incidence is unknown.
 Most cases occur in urban setting and related to
exposure attributed to alcoholism, illicit drug use,
mental illness, advanced age or homelessness
 Other affected groups include people in an outdoor
setting for work or pleasure

43. Definition
 Accidental or intentional drop of body core
temperature to 35° C or below
 95°F corresponds to 35°C, and 82°F to 28°C,
thresholds of mild and severe hypothermia.
 Mild – 32-35° C
 Moderate – 28-32° C
 Severe - <28° C

44. 4 Mechanisms of Heat Regulation
 Evaporation: most efficient
 30% body cooling at average temperatures due to
evaporation.
 Radiation: transfer of heat between body and
environment via electromagnetic waves.
 Accounts for >50% of cooling, as long as ambient air
temperature is lower than body temperature.
 Conduction: Direct transfer of heat between two objects
in direct contact.
 Important when lying on cold ground or immersed in
water.
 Convection: Heat transfer between body and a moving
gas or liquid – typically air and water.
 Think of a fan in a hot bedroom.

45. Causes of Hypothermia
 Decreased heat production – endocrine
derangements, malnutrition, neuromuscular
inefficiencies
 Increased heat loss – immersion, vasodilatation from
pharmacologic or toxic causes, burns
 Impaired thermoregulation – CNS trauma/tumors,
strokes, toxic and metabolic derangements, ICH
 Other – sepsis, uremia, multiple trauma

46. Mild (32-35° C)
 Cold temperature defense mechanisms are still
working
 Shivering, pale and cold
 Lethargy, confusion, altered judgment
 Loss of fine motor coordination
 Ataxia
 Apathy

47. Moderate (28-32°C)
 BP, HR, and RR decreased
 Delirium
 Slowed reflexes
 Stop Shivering (require active rewarming)
 Stupor
 At risk for dysrhythmias
 Further CNS depression

48. Severe (<28°C)
 Unresponsive or comatose (look dead)
 Dysrhythmias common, including ventricular
fibrillation (rewarming needed to convert)
 Rigidity
 Apnea
 Absent pulse
 Areflexia and fixed pupils

49. CNS
 Progressive deterioration from confusion to coma
 Areflexia below 28° C
patellar reflex is last to disappear
 EEG – flat at about 19° C
 If not a primary exposure, need to investigate for
CNS pathology

50. Cardiovascular
 Bradycardia
 Dysrhythmias – initially atrial fibrillation
 Decreased cardiac output
 Hypotension
 Risk of ventricular fibrillation greatest <22 C
 J wave or Osborne wave

51. J wave or Osborne wave

52. J wave or Osborne wave

53. Respiratory
 Initial stimulation of respiratory drive
 Progressive decline in minute ventilation
 Bradypnea
 Bronchorrhea
 Cough is impaired and aspiration is common
 Pulmonary edema

54. Other Systems
 “Cold diuresis” so these patients are often very
hypovolemic
 GI motility is decreased
 Insulin is inactivated

55. Diagnostics
 CBC, coagulation studies
 UA, BUN, Cr
 Electrolytes, glucose
 CXR
 ECG
 ABG – DO NOT CORRECT

56. Treatment
 Handle all victims carefully
 Prevent further heat loss
 Anticipate an irritable myocardium and hypovolemia
 Treat hypothermia before treating frostbite

57. Treatment
 Immobilize c-spine if any question of trauma
 Airway – intubate if necessary; be ready for
dysrhythmias
 Breathing – provide warm oxygen
 Circulation – IV NS; avoid LR initially
 Disability – record quick neurologic exam
 Expose – remove wet clothes, look for injuries

58. Treatment
 Measure temperature with low-reading esophageal,
rectal or bladder thermometer
 Consider thiamine, D50, narcan
 Use fluids before vasopressors
 Look for hidden trauma
 Look for potential cause
 Watch for “afterdrop”

59. Rewarming
 Active Rewarming necessary for Moderate to Severe
 Passive external
 Active external
 Active internal (core)

60. Passive Rewarming
 Passive external:
 Remove wet clothing
 Block the wind
 Keep dry
 Cover with dry insulating materials, i.e., clothes,
blankets, sleeping bags, “space” blanket

61. Active External Rewarming
 Active Rewarming necessary for Moderate to Severe
 Active external
 Apply hot water bottles, bags of saline to core areas,
i.e., neck, axillae, groin – avoid thermal burns
 Heat lamps or forced-air heating systems
 Immersion in 104 F water (impractical for most of our
ED patients)

62. Active Internal (Core) Rewarming
 Heated humidified oxygen via mask or ETT
 Heated IV fluids
 Gastric, bladder, rectal lavage – very little heat
transfer, potential complications
 Peritoneal lavage
 Thoracic lavage
 Cardiopulmonary bypass

63. Swiss Staging System
63

64. Quiz
 What is the best treatment for a hypothermic patient
(core temperature 30 C) who is manifesting ectopy
on the monitor?
 A. Lidocaine
 B. Defibrillation
 C. Rapid Rewarming
 D. Overdrive Pacing

65. Quiz
 What is the best treatment for a hypothermic patient
(core temperature 30 C) who is manifesting ectopy
on the monitor?
 A. Lidocaine
 B. Defibrillation
 C. Rapid Rewarming
 D. Overdrive Pacing

66. Frostbite-Freezing of the skin
 Pre-Freeze – secondary to chilling; vasospasticity
 Freeze-Thaw – caused by actual ice crystal
formation
 Vascular stasis – changes in blood vessels, including
spasticity and dilation; plasma leakage, stasis
coagulation, thrombosis
 Late Ischemic – result of thrombosis; tissue necrosis,
gangrene
Photo: N. Kman, MD

67. Degrees of Injury
 Difficult to predict extent of injury on initial evaluation
 Classified like burns
 Fingers, toes, nose, ears, and genitalia are first to
suffer
 Symptoms: coldness, numbness, stinging, burning,
pain, throbbing
ATLS

68. First Degree (Superficial)
 Erythema
 Numbness
 White or yellowish plaque
 Edema

69. Second Degree (Superficial)
 Erythema
 Edema
 Superficial blisters
 Blisters with clear or milky fluid

70. Third Degree (Deep)
 Complete freezing of skin and tissue
 Deeper blisters with hemorrhagic fluid
 Injury is deep into the dermis

71. Fourth Degree (Deep)
 Injury is completely through the dermis and
involves the subcuticular tissues
 Leads to mummification with muscle and bone
involvement

72. Treatment
 Address life-threatening conditions first, esp.
hypothermia
 Rapid rewarming is treatment of choice
 Do NOT rewarm if there is any chance of re-freezing
 Do NOT rewarm by massaging
 Treat like a burn

73. Treatment
 Immersion in circulating warm water (40-42°C)
 Narcotics are often needed
 Rewarm until the skin is pliable and erythematous at
the most distal part
 Blisters – care is controversial although most agree
to debride clear blisters
 Tetanus prophylaxis

74. Treatment
 Pad between fingers, toes, and all splints
 Elevate
 Ibuprofen
 Aloe vera
 Observation for necrosis and demarcation

75. Quiz
 Which degree of frostbite is associated with full-
thickness skin involvement with muscle and tendon
involvement & hemorrhagic bullae?
 a. First degree
 b. Fourth degree
 c. Second degree
 d. Third degree

76. Quiz
 Which degree of frostbite is associated with full-
thickness skin involvement with muscle and tendon
involvement & hemorrhagic bullae?
 a. First degree
 b. Fourth degree
 c. Second degree
 d. Third degree

77. Heat-Related Illness
Photo: N. Kman, MD

78. Statistics
 About 500 die each year in the U.S.
 Hard to know exact number because it’s often under-
reported
 800 dead in Chicago 1995
 August 2003: at least 35,000 died in Europe
 2006 North America: at least 225 deaths
 2006 Europe: 1000 heat-related deaths in the
Netherlands

79. Heat Illness
 Elderly are at risk for classic heatstroke
 Children: 3 risk groups
1. neonates
2. toddlers
3. adolescents

82. Mechanisms
 Increased heat production
 Decreased heat dissipation – radiation and
evaporation
 Impaired thermoregulation – illness, drugs, behavior

83. Spectrum of Illness
Heat
Edema
Heat
Syncope
Heat
Cramps
Heat
Exhaustion
Heat
Stroke

84. Heat Cramps
 Painful spasmodic cramps that usually occur in
heavily exercised muscles (Large Groups, Calves)
 Onset may be during exercise or after
 Likely the result of water and sodium loss
 Oral rehydration with water and electrolytes
 Rest in cool environment
 Stretch and massage

85. Heat Edema
 Peripheral edema developing during the first few
days in a hot environment
 Usually self-limited – does not require medical
therapy

86. Heat Syncope
 Orthostatic hypotension resulting from
volume depletion, peripheral
vasodilatation, & decreased
vasomotor tone.
 Trendelenburg
 Cool victim and administer oral fluids –
carbohydrate-containing fluids
absorbed up to 30% faster (dilute
Gatorade)

87. Heat Exhaustion
 Flulike symptoms – intense thirst, malaise,
headache, weakness, nausea, anorexia, vomiting
 Tachycardia, orthostatic hypotension
 Sweating is generally present
 Core Temperature is < 104 F
 Mental status and neurologic exam are normal

88. Heat Exhaustion
 Cool shaded environment
 Oral rehydration if capable but may need IVF due to
large amounts of volume lost as sweat
 Active cooling measures – ice packs to neck, axillae,
groin
 Spray with tepid water and fan – one of the most
effective ways to cool

89. Heat Stroke
 Medical Emergency!
 Temperature generally > 104° F
 MENTAL STATUS CHANGES
 Delirium
 Seizures
 Coma
 Skin is usually hot and dry
 Classic versus Exertional

90. Heat Stroke
 Classic
 Environment plays
major role
 Linked to heat waves
 Dry skin
 Elderly
 Respiratory alkalosis
 Exertional
 Intrinsic heat production
plays major role
 All types of weather
 Profuse sweating
 Athletes
 Respiratory alkalosis
and lactic acidosis

91. Heat Stroke
 Tachycardia
 Orthostatic changes, hypotension
 Hyperventilation
 Bleeding due to coagulation disorders, including DIC
 Classic – respiratory alkalosis
 Exertional – respiratory alkalosis and lactic acidosis

92. Multi-Organ Dysfunction
 Encephalopathy
 Rhabdomyolysis
 Acute renal failure
 Acute respiratory distress syndrome
 Myocardial/hepatocellular/pancreatic injury
 Intestinal ischemia/infarction
 Hemorrhagic complications – DIC

93. Treatment
 Immediate cooling
 Support of organ-system function

94. Cooling
 Ice packs on neck, axillae, chest wall, and groin
 Spray with tepid water and fan rapidly to cool by
evaporation; massage the skin
 Immersion in cool water, if vital signs are otherwise
stable
 Stop active cooling at core temperature of 102 F
 Internal cooling rarely needed/used

95. Treatment
 ABCs
 IVF – treat volume depletion
 Avoid shivering
 Benzodiazepines for seizures/shivering
 Dantrolene is ineffective
 Monitor for complications and treat

96. Good Prognosis
 Recovery of central nervous system function during
cooling
 Expected in the majority of patients who receive
prompt and aggressive treatment

97. Poor Prognosis
 Coagulopathy with liver hepatocyte damage
 Lactic acidosis in classic form
 Rectal temperature > 108 F
 Prolonged coma of more than 4 hours
 Acute renal failure
 Hyperkalemia
 AST > 1000 U/L

98. Quiz
 A patient presents from OSU Football practice with a
core temperature of 105 and altered mental status
(says he wants to play for Michigan). What is the
best cooling technique?
 A. Ice Bath to core temperature of 96 F
 B. Ice packs to the forehead
 C. ECMO
 D. Cooling Fans with mist to core temperature of 102

99. Quiz
 A patient presents from OSU Football practice with a
core temperature of 105 and altered mental status
(says he wants to play for Michigan). What is the
best cooling technique?
 A. Ice Bath to core temperature of 96 F
 B. Ice packs to the forehead
 C. ECMO
 D. Cooling Fans with mist to core temperature of
102

100. Insect Bites and Stings

101. Insect Bites and Stings
Casale, Thomas B (04/10/2014). "Clinical practice. Hymenoptera-sting hypersensitivity". The New England journal
of medicine (0028-4793), 370 (15), p. 1432.

102. Hymenoptera Stings
 Stinging insects kill more people annually than do
snakes
 About 40-130 deaths per year
 Three families
 Hornets, wasps and yellow jackets
 Bees
 Ants and fire ants

103. Hymenoptera and Distribution
Freeman TM. Hypersensitivity to Hymenoptera Stings. N Engl J Med 2004;351:1978-84.

104. Reactions
 Local
 Mild generalized
 Severe generalized

105. Local
 Majority of cases
 Local redness, pain, swelling
 May extend more than 6 inches beyond the sting
 May persist longer than 24 hours
 Remove stinger
 Ice, elevate
 Antihistamines, steroids, tetanus prophylaxis

106. Mild Generalized
 Symptoms away from site– itching, hives, nausea,
wheezing
 Antihistamines, steroids
 Inhaled beta-agonists for wheezing
 Tetanus prophylaxis
 Local care
 Observation for 6-8 hrs
 Consider Epi-pen if wheezing

107. Severe Generalized
 Classically IgE-antibody mediated
 Anaphylaxis, laryngoedema, circulatory collapse,
LOC
 Most deaths generally occur within 1st hour

108. Severe Generalized
 ABCs – intubate early
 IVF – support blood pressure
 Epinephrine is drug of choice (0.01 mg/Kg of 1:1000
solution) – initially IM but may need IV drip
 Steroids
 Inhaled beta-agonists for bronchospasm
 H1/H2 blockers (Diphenhydramine and Cimetidine)

109. Severe Generalized
 Admit all
 Home with Epi-Pen
 Refer for desensitization therapy

110. Quiz
 About how many bee stings does it take to die from
venom overdose?

111. Answer
 Approx 300-500 stings

112. Ant Stings
 Ants sting 9.3 million people each year. Other
Hymenoptera account for more than 1 million stings
annually.
 Fire-ant venom is
composed primarily of a
transpiperidine alkaloid
that causes tissue
necrosis.

113. Ant Stings
 Most fire-ant stings produce
blister within 24 hours, which
fills with necrotic material,
giving appearance of pustule.
 Despite appearance,
blisters are not infected
and should be left intact.
Casale, Thomas B (04/10/2014). "Clinical practice. Hymenoptera-sting
hypersensitivity". NEJM, 370(15), p.1432

114. Key Points: Insect Stings
 ABC's
 Remove Stinger
 Epinephrine for generalized reactions
 There are NO contraindications to epi
 Steroids, Benadryl, Pepcid
 Admit all severe reactions, d/c with Epi Pen

115. Questions?