Environmental Emergencies I
Nicholas E. Kman, MD FACEP
Associate Professor
The Ohio State University
Department of Emergency Medicine
Objectives
Thermal Injuries Burns Electrical Injuries Lightning Injuries
Cold Related Injuries Hypothermia Frost Bite
Heat Related Illness Insect Bites and Stings
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
Thermal Injury
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
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.
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)
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
Rule of 9’s
Lund and Browder burn diagram - more precise - age-adjusted
Burn Depth
Based on need for surgical intervention No objective method for measuring depth Based on clinical features/judgment Burns are dynamic
First Degree
Only epidermal layer Skin red, painful and tender without blisters Heals in about 7 days Symptomatic treatment
Second Degree
Superficial partial-thickness
Deep partial-thickness
Superficial Partial Thickness
Epidermis and superficial dermis injured Skin blistering, moist at blister’s base, painful Heals in 14-21 days Scarring is minimal
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
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
Fourth Degree
Extends through skin into subcutaneous fat, muscle and even bone
Devastating, life-threatening Amputation or extensive reconstruction needed
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
American Burn Association
Classification of burns – major, moderate and minor
Burn unit referral criteria
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
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
Treatment
Airway with c-spine immobilization For facial burn, singed nasal hair, soot in mouth- Early intubation 100% O2 COHgb level
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
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.
Secondary Assessment
Head to toe assessment Check for corneal burns of eyes Calculate BSA NG tube, foley for more than 20% BSA
burns
Diagnostic Studies
CBC, BUN, Cr, glucose Blood gas UA – myoglobin CXR – inhalational injury ECG – electrical injury
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
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
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
Electrical Injuries
1000 - 1300/year in U.S. 25% lightning (30% mortality) 15% overall mortality
High-risk groups Electricians/builders Industry Toddlers
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!)
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.
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
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
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
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/
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
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
Hypothermia and Frostbite
41
Brown DJ, Brugger H, Boyd J, Paal P. Accidental hypothermia. N Engl J Med. 2012;367(20):1930-8.
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
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
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.
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
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
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
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
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
Cardiovascular
Bradycardia Dysrhythmias – initially atrial fibrillation Decreased cardiac output Hypotension Risk of ventricular fibrillation greatest <22 C J wave or Osborne wave
J wave or Osborne wave
J wave or Osborne wave
Respiratory
Initial stimulation of respiratory drive Progressive decline in minute ventilation Bradypnea Bronchorrhea Cough is impaired and aspiration is common Pulmonary edema
Other Systems
“Cold diuresis” so these patients are often very hypovolemic
GI motility is decreased
Insulin is inactivated
Diagnostics
CBC, coagulation studies UA, BUN, Cr Electrolytes, glucose CXR ECG ABG – DO NOT CORRECT
Treatment
Handle all victims carefully Prevent further heat loss Anticipate an irritable myocardium and hypovolemia Treat hypothermia before treating frostbite
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
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”
Rewarming
Active Rewarming necessary for Moderate to Severe
Passive external
Active external
Active internal (core)
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
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)
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
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
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
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
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
First Degree (Superficial)
Erythema Numbness White or yellowish plaque Edema
Second Degree (Superficial)
Erythema Edema Superficial blisters Blisters with clear or milky fluid
Third Degree (Deep)
Complete freezing of skin and tissue Deeper blisters with hemorrhagic fluid Injury is deep into the dermis
Fourth Degree (Deep)
Injury is completely through the dermis and involves the subcuticular tissues
Leads to mummification with muscle and bone involvement
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
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
Treatment
Pad between fingers, toes, and all splints Elevate Ibuprofen Aloe vera Observation for necrosis and demarcation
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
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
Heat-Related Illness
Photo: N. Kman, MD
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
Heat Illness
Elderly are at risk for classic heatstroke
Children: 3 risk groups
1. neonates
2. toddlers
3. adolescents
Mechanisms
Increased heat production Decreased heat dissipation – radiation and
evaporation Impaired thermoregulation – illness, drugs, behavior
Spectrum of Illness
HeatEdema
HeatSyncope
HeatCramps
HeatExhaustion
HeatStroke
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
Heat Edema
Peripheral edema developing during the first few days in a hot environment
Usually self-limited – does not require medical therapy
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)
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
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
Heat Stroke
Medical Emergency! Temperature generally > 104° F MENTAL STATUS CHANGES
Delirium Seizures Coma
Skin is usually hot and dry Classic versus Exertional
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
Heat Stroke
Tachycardia Orthostatic changes, hypotension Hyperventilation Bleeding due to coagulation disorders, including DIC Classic – respiratory alkalosis Exertional – respiratory alkalosis and lactic acidosis
Multi-Organ Dysfunction
Encephalopathy Rhabdomyolysis Acute renal failure Acute respiratory distress syndrome Myocardial/hepatocellular/pancreatic injury Intestinal ischemia/infarction Hemorrhagic complications – DIC
Treatment
Immediate cooling
Support of organ-system function
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
Treatment
ABCs IVF – treat volume depletion Avoid shivering Benzodiazepines for seizures/shivering Dantrolene is ineffective Monitor for complications and treat
Good Prognosis
Recovery of central nervous system function during cooling
Expected in the majority of patients who receive prompt and aggressive treatment
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
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
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
Insect Bites and Stings
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.
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
Hymenoptera and Distribution
Freeman TM. Hypersensitivity to Hymenoptera Stings. N Engl J Med 2004;351:1978-84.
Reactions
Local
Mild generalized
Severe generalized
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
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
Severe Generalized
Classically IgE-antibody mediated Anaphylaxis, laryngoedema, circulatory collapse,
LOC Most deaths generally occur within 1st hour
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)
Severe Generalized
Admit all Home with Epi-Pen Refer for desensitization therapy
Quiz
About how many bee stings does it take to die from venom overdose?
Answer
Approx 300-500 stings
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.
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
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
Questions?
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