© 2011 Seattle / King County EMS CBT385-EMT11: Environmental Emergencies 2011.

© 2011 Seattle / King County EMS

CBT385-EMT11: Environmental Emergencies 2011


Introduction• Heat & cold illnesses triggered when body

unable to maintain constant temperature• In addition to heat & cold-related illnesses,

this course addresses:• Diving emergencies• Stings & bites• Gas poisoning


Objectives1. Identify the ways the body produces and loses heat.2. Identify examples of conduction, convection, radiation

and evaporation.3. Identify factors that affect heat production and heat

loss.4. Identify signs and symptoms of heat-related

emergencies.5. Identify signs and symptoms of cold-related

emergencies.6. Identify emergency care for heat- and cold-related

emergencies and drowning.7. Identify the two primary components of anaphylaxis

and emergency care for the condition.


Termscore temperature — The operating temperature of an organism. Also, the temperature of the body’s internal structures.

diuretic — A drug such as Lasix (furosemide) and HCTZ (hyrdrochlorothiazide) used in treating congestive heart failure and other ailments. They can cause dehydration making a person more susceptible to heat stress.

evaporation — The conversion of a liquid to a gas.


Terms, continuedLOC — Abbreviation for level of consciousness.

metabolism — The human body produces heat by converting food to energy. All bodily functions such as digestion, muscle contractions and breathing require energy. Heat is a by-product of these processes. The body's temperature-control mechanism, located in the hypothalamus region below the brainstem, maintains a core temperature of about 98°F (37°C). There is a balance between production and loss.

tachypnea — A rapid respiratory rate.


New Termsconduction — Conduction is a transfer process by which heat moves between two touching objects from the warmer object to the colder object. It is the motion of molecules bumping into one another, like billiard balls that spreads heat. convection — Convection is the transfer of heat due to movement of a gas or liquid in response to a temperature or pressure differential. It occurs when a moving gas (e.g., air) or liquid carries heat from a warmer body to a cooler body. It can also work in reverse, carrying heat from a warmer environment to a cooler one. Rising warm air from the earth's surface is an example of convection.

electrocution — Termination of life (stopped heart) by any type of electric shock.

radiation — Radiation occurs when a warm body releases energy without direct contact with another body. Not only can heat energy travel by bumping molecules (as in conduction), it can also travel through electromagnetic waves. .


HEAT PRODUCTION AND LOSS


Heat ProductionFour ways body can produce heat:• Metabolism• Shivering• Exercise• External heat sources


MetabolismMetabolism• Conversion of food to energy • Activity of bodily functions (such as circulation, respiration and muscle tone)

• Some substances broken down to create energy while other substances are synthesized into tissue building material


Shivering • Rapid contraction & expansion of muscle tissues• Shivering can produce 40 times more heat than baseline metabolism


Exercise • Produce heat through exercise• Happens as long as there is activity, fuel (for instance, glucose or fat), oxygen and water


External Heat Sources External heat sources come from environment • Sun• Fire• Chemical sources


Factors That Affect Heat Production Many factors affect how well body can

produce heat:• Core temperature• Medical conditions• Body fluid status (dehydration)• Drugs and chemicals


Factors That Affect Heat Production Core Temperature • Colder body – less able it to produce adequate heat through metabolism• Hypothermia greatly reduces body’s ability to produce heat

– Cooling slows chemistry of body

Medical Conditions • Cardiac disease decreases ability to compensate for heat stress• Endocrine diseases such as thyroid, adrenal & insulin deficiencies may contribute to hypothermia• Strokes can cause immobility with reduced muscular activity Temperature control centers of brain may be damaged


Factors That Affect Heat Production Body Fluid Status • Metabolism is not as efficient when the body is dehydrated• Dehydration is a common problem in hot environments.

Drugs and Chemicals • Beta-blockers decrease cardiac output & peripheral vascular control mechanisms

– Effect works to lower body temperature

• Drugs such as cocaine and amphetamines may contribute to hyperthermia (heatstroke)

– Mimic stimulation of sympathetic nervous system


Heat Loss

Four heat loss mechanisms are:• Conduction• Convection• Radiation• Evaporation

Under normal conditions, heat loss mechanisms are balanced with heat

production mechanisms

Under normal conditions, heat loss mechanisms are balanced with heat

production mechanisms


Conduction• Transfer process – heat moves between two touching objects

– From warmer object to colder object

• Motion of molecules bumping into one another spreads heat• Molecules bump around like billiard balls on a billiards table• Major source of heat loss in case of cold-water immersion

– Water conducts heat 25 times more quickly than air


Convection• As air warms, rises & cooler air replaces it

– Cool air then is warmed– Example – blow on your food to cool it

• Transfer of heat between body & air or water that surrounds it• Occurs when a gas or liquid carries heat away• Body’s heat energy is lost more rapidly in moving air or water• Example – rising warm air from earth’s surface


Radiation • Warm body releases energy without direct contact• Heat energy travels by bumping molecules (as in conduction)

– Also travel through electromagnetic waves

• Sun is best known example of heat transfer through radiation


Evaporation • Conversion of a liquid to a gas• Heat pan of water, energy applied to water will cause to evaporate

– Requires a lot of heat– Takes a lot of energy to break water molecules apart & convert liquid to gas

• Human body takes advantage of evaporation’s heat loss powers by sweating


HEAT ILLNESS


Heat Cramps

• Heat cramps or muscle cramps result from uneven distribution of body fluids & salts

• Muscle cramps from this condition can be mild to severe, involving the extremities or the abdomen

• Cramps can be accompanied by:– Dizziness– Weakness– Nausea


Heat Exhaustion • Named for feeling of exhaustion people experience • Result of excessive heat & dehydration

– Reduce circulating blood volume & increase peripheral pooling due to vasodilation

• Cooling mechanisms of radiation & evaporation become inefficient due to loss of fluids :

Clinical findings associated with heat exhaustion include:

– Dizziness, weakness and nausea– Rapid, weak pulse– Cool, clammy skin– Profuse sweating– Altered LOC


Heatstroke • Life-threatening emergency – occurs when body's heat-regulating ability fails• Happens when body is subjected to more heat than it can deal with & four heat loss mechanisms overwhelmed

Clinical findings of heatstroke include:

– Altered LOC (confusion, disorientation, or unconsciousness)– Rapid, bounding pulse– Rapid, deep respirations– Hot, dry, flushed skin*– Dilated pupils– Seizures

* Can be damp if rapid onset


Emergency Care for Heat-Related Emergencies

• Reduce core temperature:– Remove or loosen clothing– Provide a cool environment– Apply cool packs

• Request paramedics when ALS indicators are present

• provide oxygen and/or ventilatory assistance• Position patient appropriately• Monitor vital signs• Patient responsive & not nauseated, consider

giving water


Cooling Strategies

Provide a Cool Environment • As soon as time allows, move patient to back

of air-conditioned aid car with the air conditioner running on maximum

• Fan patient aggressively if staffing allows• Keep skin wet by applying cool water with a

sponge or wet towel


Cooling Strategies

Remove Clothing• Loosen or remove clothing to promote

efficient convention• Consider applying water with a sponge

or wet towels on patient’s skin• If you apply water to skin to encourage

evaporation, use room temperature water– Do not induce shivering


Cooling Strategies

Apply Cold Packs• Neck, groin & armpits• Hospitals generally have tools

necessary to properly lower core temperature – Do not delay transport– Notify hospital early to allow ED staff time

to prepare


COLD EXPOSURE


Hypothermia • Cooling of core temperature below 98.6°F• Caused by loss of body heat or decreased heat production• Exposure to a cool environment

– Immobile elderly person lying on a floor– Drowning victim & who has been submerged

Hypothermia can occur rapidly in wet environments


HypothermiaEarly recognition increases chances of survival

Hypothermia

Stage Signs & Symptoms

Mild Hypothermia90-95°F

•Alert, signs of fatigue & weakness•Poor circulation•Muscle stiffness

Moderate Hypothermia80-90°F

•Confusion, lethargy•Weak pulse, dysrhythmias•Slow respirations

Severe Hypothermia

less than 80°F •Coma•Fixed and dilated pupils•Cardiac arrest


Frostbite Superficial Injury - Clinical Findings • Blanching of skin• Loss of feeling & sensation in injured area• Tingling sensation if re-warmed

Deep Injury - Clinical Findings • White, waxy skin• Swelling and/or blisters• Skin can appear flushed with areas of purple & blanching or mottled & cyanotic


Emergency Care for Cold-Related Emergencies

Prehospital emergency care for a hypothermic patient is as follows:

• Remove patient from cold environment• Protect from heat loss• Provide high-flow oxygen


Emergency Care for Hypothermia Remove from Cold/Protect from Heat Loss• Move patient to aid car warmed to 80°F• Keep patient flat• Remove wet clothing• May need to protect from heat loss by insulating patient with

blankets Provide High Flow Oxygen • Provide high flow oxygen via pocket facemask or BVM for a

non-breathing patient• Recommend use of pocket facemask when ventilating a non-

breathing hypothermic patient– Helps warm patient more effectively

• Oxygen administered through BVM is ambient air temperature & low humidity

• Causes increased heat loss (through evaporation) when compared to warm, moist oxygen/air via pocket facemask– Can use a BVM if necessary


Hypothermic Cardiac Arrest Hypothermic patient in cardiac arrest or with

profound bradycardia, following guidelines apply:

• If no pulse detected after 1 minute, begin CPR & apply AED

• If breathing, assume there is cerebral perfusion, therefore NO CPR

• If AED analysis yields a “shock indicated” follow cardiac arrest protocol

• If pulse is present withhold CPR regardless of rate or BP


Emergency care for Frostbite

• Protect affected area from further injury• Remove constricting or wet clothing &

jewelry • Cover with dry bulky dressing• Splint affected extremity, prevent use

of extremity


Transport Times Over Two Hours • Do not re-warm frozen tissue unless transport

time will exceed 2 hours & you are certain the thawed tissue will not refreeze

• Obtain medical direction prior to initiating re-warming

• Re-warming should be done with 100 – 105°F water

• Do not use dry heat—it heats unevenly and can burn frozen tissue

• Stop re-warming when tissue turns red-purple & becomes pliable


WATER-RELATED


Drowning and Near Drowning • Drowning – death caused by hypoxia following submersion in water• Near drowning – submersion in water that does not result in death • Without oxygen, hypotension, bradycardia & cardiac arrest ensue

Several things you should determine:• Length of submersion• Temperature of water• Depth of water


Length of Submersion • Include length of submersion in report to

hospital staff May have to estimate based on bystander testimony & other indicators

• Submersion is short duration (2 minutes or less), a short period of CPR likely will result in successful resuscitation

• Significant number of near-drowning patients who look fine initially develop pulmonary edema several hours later

• Non-cardiac related condition is called acute respiratory distress syndrome (ARDS).


Water Temperature • Important factor in how long someone can

survive without oxygen• Cold water drowning victims (less than 70°F)

can survive for up to 1 hour without oxygen• Record for a successful resuscitation – 3-year-

old child immersed for 66 minutes in 33°F water– Children often survive longer because they cool faster

than adults

• Some studies indicate that temperatures need to be below 50°F for any significant chances of survival to occur after long immersion


Water Temperature

• Submersion times greater than 10 minutes make successful resuscitation unlikely in most warm water drowning situations

• Survival from long submersion times more likely when brain cools fast enough to receive protection from hypoxia

• People who cool before they drown (e.g., hanging onto ice or overturned boat) may have a better neurological outcome


Depth of Water • Spinal injuries seen in many water-related

accidents• Diving into shallow water common mechanism

for head & spinal injury & subsequent drowning– Potential for a spinal injury, stabilize cervical spine

while in the water, if possible

• Other conditions associated with drowning:– Skeletal & soft tissue injuries– Drug or alcohol intoxication– Underlying medical conditions


Emergency Care for Drowning/Near DrowningManagement requires prompt basic life support &

following measures: • Safely remove victim from the water• Stabilize c-spine and place patient on a backboard*• Follow resuscitation protocols for cardiac or pulmonary

arrest• Administer oxygen and/or ventilatory assistance• Place in a supine position to avoid cerebral edema • Prepare suction and expect vomiting • Warm up the aid unit• Monitor vital signs

*If spine injury is suspected or patient is unresponsive. If possible, initiate stabilization during removal from water


Air Embolism • Most SCUBA dives occur without incident, use of compressed air or other gases in an underwater environment can be hazardous• In addition to drowning, common diving-related hazards include air embolism and decompression illness bubbles into bloodstream


Air Embolism

• Air embolism – presence of gas bubbles in bloodstream that obstruct circulation– Occurs during ascent when pressure in

lungs forces air


AIR EMBOLISMSigns:• Apnea (no breathing)• Frothy fluid from nose or mouth• Loss of consciousness• Partial weakness or paralysis• Seizures• Irregular pulse• Death

Symptoms:• Dizziness• Confusion• Chest pain• Diminished sensation in parts of the body• Visual blurring


Decompression Sickness • Nitrogen in blood forms bubbles due to rapid ascent• Bubbles collect in tissues & interfere with blood flow

• Significant history for all diving emergencies includes:

– Number of dives in past 24 hours– Depth of dive– Length of time underwater– Problems encountered while diving– Significant medical history (including meds)


Decompression Sickness• Dive usually at depth of at least 33 feet

– Less likely at depths <33 feet– Still can happen

• Longer & deeper the dive, more nitrogen dissolves in blood• Dehydration, exertion & air travel within 12 hours after diving all increase the probability of DCI

• Symptoms of DCI vary widely depending on where bubbles collect

– Joint pain, abdominal pain, neurological symptoms & difficulty urinating are common– Diver who complains of feeling ill after diving should be evaluated for DCI– Symptoms can appear within a few minutes of surfacing or it may take hours


ALLERGIC REACTION


Stings and Bites

Insects & spiders inject a poison when they bite or sting

Two types of spiders deliver life-threatening bites: brown recluse & female black widow

Brown recluse Black widow


Stings and Bites

• Many marine animals, such as sharks or urchins, have spines that contain proteins that can cause a local reaction and, occasionally, an anaphylactic reaction

• Some tropical species (e.g., the Lionfish) found in aquariums can cause envenomation.


Stings and Bites

Significant history should include:• Type of animal or insect• Behavior of animal• Time of day the bite occurred• Location of animal


Stings and Bites

Mild swelling with fairly-well localized cellulitis

More extensive cellulitis – spreading beyond immediate injury site

Necrotic skin surrounded by swelling & extensive cellulitis

Day 3 Day 6 Day 10


Allergic Reactions

• Allergen – body’s exaggerated response to a foreign material

• Anaphylaxis or anaphylactic shock refers to severe, often life-threatening allergic reaction

• Two primary components of anaphylaxis:– Severe respiratory distress– Hypotension


Allergic ReactionsSigns of severe respiratory distress:

– Shortness of breath– Dyspnea– Stridor– Wheezing– Cyanosis– Decreased level of consciousness due to hypoxia and hypotension

Hypotension – Caused by dilation & leaking of blood vessels– Problem is compounded by hypoxia


Allergic Reaction vs. Anaphylaxis Allergic Reaction• Localized

– Raised area on the skin from a sting or bite

• Can become systemic & affect respiratory & circulatory systems

Anaphylaxis• Severe reaction that often affects several body systems• Two primary components to life-threatening anaphylaxis:

– Severe respiratory distress– Hypotension


Emergency Care for Allergic Reaction Stings and Bites • Most important thing you can do in case of

sting or bite – treat any respiratory difficulties by maintaining ABCs & administering oxygen as needed

• Other care measures include:– Request paramedics if indicated– Scrape the sting site to remove the stinger – Wash area– Remove jewelry from affected limb before swelling

begins, if possible– Bandage and immobilize site of injury– Treat for shock– Administer epinephrine via EpiPen if indicated


Emergency Care for Allergic ReactionAnaphylaxis • After determined patient is indeed in

severe respiratory distress & hypovolemic• Emergency care for anaphylaxis includes:

– Request paramedics– Provide oxygen and/or ventilatory assistance– Position patient appropriately– Administer epinephrine via EpiPen– Monitor vital signs


GASES & ELECTRICITY


Gas Poisoning

• Most gas poisonings deaths result of exposure to carbon monoxide, a colorless & odorless gas that blocks body’s ability to deliver oxygen to tissues

• Exposure to cleaning products, industrial chemicals & gases also contribute to many injuries & deaths


Gas PoisoningSigns & symptoms of carbon monoxide poisoning: • Headache• Tachypnea• Nausea and vomiting• Altered LOC• Pink, flushed mucus membranes• Coma

Note that pulse oximetry readings can be unreliable in a gas poisoning situation

Note that pulse oximetry readings can be unreliable in a gas poisoning situation


Electrocution

• Termination of life (stopped heart) by any type of electric shock

• Common vernacular, term is used to mean: accidental injury, death, murder or suicide by electric shock, and deliberate execution by electric shock (usually involving an electric chair)


Electrocution

Don’t go near downed power line

Entrance Wound - Dark spot in center of wound

Exit Wound – where body closest to ground


Emergency Care Gas PoisoningEmergency care for inhaled poisons

includes the following:• Scene safety• Remove patient from toxic environment• ABCs• Monitor airway and provide high flow

oxygen• Request paramedics if necessary• Contact poison control if needed


Emergency Care Electrocution – Power Lines• Scene Safety• Do not touch any downed power lines or

anything power lines may be in contact with• Wear appropriate PPE• Be aware of marked danger zones• Remove patient to place of safety, once given

OK by qualified personnel• ABCs• Provide full spinal stabilization• Look for two burn sites: an entrance & exit site• Transport


Emergency Care Electrocution - Lightning• Scene Safety• Take measures to protect yourself from being

struck by lightning• Remove patient to place of safety, under

shelter, if available• ABCs• Provide full spinal stabilization• Look for two burn sites: an entrance & exit site• Transport


Case Studies

Video Case Study #1http://www.emsonline.net/environ2011/case1.asp

Video Case Study #2http://www.emsonline.net/environ2011/case2.asp


Summary• Four mechanisms that cause heat loss:

conduction, convection, radiation, & evaporation

• Heat cramps, heat exhaustion, & heatstroke are progressive phases of heat illness managed in field by reducing core temperature

• Steps for prehospital emergency care for a hypothermic patient include remove patient from cold environment, protect patient from heat loss, & provide high flow oxygen


SummaryManagement of drowning and near drowning

includes: – Safely remove victim from the water– Stabilize c-spine and place patient on a backboard*– Follow resuscitation protocols for cardiac or pulmonary

arrest– Administer oxygen and/or ventilatory assistance– Position patient in a supine position to avoid cerebral

edema– Prepare suction and expect vomiting – Warm the aid unit– Monitor vital signs

* If spine injury is suspected or patient is unresponsive. If possible, initiate stabilization during removal from water.


SummaryTwo primary components of anaphylaxis:• Severe respiratory distress• Hypotension

Emergency care for anaphylaxis includes:• Request paramedics• Provide oxygen and/or ventilatory assistance• Position patient appropriately• Administer epinephrine via EpiPen• Monitor vital signs


Summary

Signs & symptoms of carbon monoxide poisoning include:

• Headache• Tachypnea• Nausea and vomiting• Altered LOC• Pink, flushed mucus membranes• Coma


Summary

• Electrocution - two primary types of electrocution are by lightning and power lines

• Burns are not always major crisis associated with electrical shock

• Respiratory issues & cardiac arrest are valid concerns– Ventricular Fibrillation most commonly seen

dysrhythmia associated with cardiac arrest

© 2011 Seattle / King County EMS CBT385-EMT11: Environmental Emergencies 2011.

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Transcript of © 2011 Seattle / King County EMS CBT385-EMT11: Environmental Emergencies 2011.