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?