BLS 2014: Environmental Emergencies. This course addresses: Cold and heat related emergencies ...

© 2013 Seattle / King County EMS

BLS 2014: Environmental Emergencies


This course addresses: Cold and heat related emergencies Water emergencies Stings & bites Anaphylaxis and use of the epi-pen Toxic gases Electric shock and lightning strike

Introduction


Objectives Identify the ways the body produces and loses heat. Identify signs, symptoms, and emergency care of heat-

related emergencies. Identify signs, symptoms, and emergency care of cold-

related emergencies. Identify signs, symptoms, and emergency care of

water-related emergencies Identify signs, symptoms, and emergency care of bites

and stings Identify signs, symptoms, and emergency care of

anaphylaxis and severe allergic reaction Identify signs, symptoms, and emergency care of bites

and stings Identify signs, symptoms, and emergency care of toxic

gas exposure Identify signs, symptoms, and emergency care of

electric shock and lightning strike


Heat Production and Loss


Heat Production

Three ways body can produce heat: Metabolism Shivering Exercise


Metabolism Metabolism

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


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


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


Hypothermia

Early recognition increases chances of survival

HypothermiaStage 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 Pre-hospital 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 BVM for

a non-breathing patient


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 Several things

you should determine: Length of

submersion Temperature of

water Depth of water

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


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 Submersion times greater than 10

minutes make successful resuscitation unlikely

High survival rates for cold water drowning's are a myth – there are rare cases of successful resuscitations after long submersions, but most long submersions do not survive, or survive with devastating neurologic outcomes.

Contrary to popular belief, children do not have better neurologic outcomes than adults


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 Drowning Management 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.


Diving Emergencies Use of compressed air in an

underwater environment can be hazardous

In addition to drowning, common diving-related hazards include air embolism and decompression illness


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


Treatment for Diving InjuriesDefinitive treatment for any significant diving emergency is recompression in a hyperbaric facility!

Emergency care ABCs High flow 100% oxygen Place the patient in a position of comfort (“head down, feet

up” is no longer recommended) Request ALS intervention as needed

Gather information on: Maximum depth dived Time on the bottom Time since reaching surface Whether the dive was single or multiple dives were done.

If the patient is to be flown by helicopter then advise the crew that this is a decompression accident. This prepares the crew for low fly or cabin pressure alterations during flight.


Bites and Stings


Bites and stings

Animals of all types from dogs to bees may bite or sting to defend themselves or their young. Bites and stings can cause problems ranging from local tissue damage to systemic symptoms.


Mammal Bites and Scratches Local tissue damage Bleeding (can be significant depending on the

size of the animal and patient, and location of the wound)

Puncture wounds increase the risk of infection Remote risk of rabies (viral disease transmitted

by saliva of infected mammals)

Emergency care ABCs Control bleeding, sterile dressing Identify the animal (contain if possible) Evaluation at ER or clinic for possible antibiotics


Snake Bites Snakes bite if threatened or to obtain food

(typically small mammals) Only a small percentage of snakes in the US

are poisonous Even poisonous snakes often bite without

envenomation Sometimes people keep poisonous snakes as

pets Alcohol use is a significant factor in many

snakebites Signs and symptoms range from local tissue

damage to systemic effects, and vary depending on the type of snake

Zoos are excellent sources of information about snakebites and often stock antivenom


Snake Bites

Emergency care Non-poisonous snake: wound care Poisonous snake:

ABCs Request ALS if indicated Constricting bands, suction of bite are no

longer recommended Remove jewelry from affected limb before

swelling begins, if possible Bandage and immobilize site of injury


Invertebrate Stings and Bites

Include bees and wasp stings, spider bites, and stings of marine animals such as urchins

Reactions can include tissue irritation, local allergic reaction, anaphylaxis, or systemic symptoms

If possible, identify the type of animal responsible for the bite/sting


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.


Emergency Care for Invertebrate Bites and Stings

Request ALS if indicated Scrape the sting site to remove the

stinger Wash the area Remove jewelry from affected limb

before swelling begins, if possible Bandage and immobilize site of

injury If there are signs and symptoms of

anaphylaxis or severe allergic reaction, administer epinephrine via EpiPen if indicated


Anaphylaxis/Severe Allergic Reaction

Exaggerated response of the body to a foreign protein (for example, the venom in a bee sting or peanuts)

Caused by an overproduction of histamine

Too much histamine causes: Vasodilitation, resulting in hypotension Bronchoconstriction, resulting in dyspnea GI distress, including diarrhea and

abdominal pain There may also be local or generalized

swelling and widespread urticaria (hives)


Emergency Care for Anaphylaxis ABCs Request ALS Oxygen Trendelenberg if patient is

hypotensive Administer epinephrine via EpiPen


Epi-pen AdministrationInjection Procedure for the Epi-Pen or epi-pen jr:1. Check medication date and that the EpiPen dose matches

with the patient’s size.2. Remove the patient’s clothing and prep the thigh with an

alcohol pad.3. Remove safety cap and locate injection site on lateral

thigh.4. Place the black tip of the injector against the patient’s

thigh and push hard until it activates.5. Hold it in place for 10 seconds, and document the time of

injection.6. Remove the injector and place it in a sharps container.

Massage the injection site for 10 seconds.7. Reassure the patient and monitor for response and side

effects to the injection.8. Continue to provide oxygen. Ventilate the patient if

necessary.9. Monitor and document patient vitals every 5 minutes.10. Update incoming medics on patient status and response to

the injection.


Toxic Gases


Toxic Gas Poisoning Scene safety is of paramount importance Determine type of exposure and length of time

exposed Consider toxic gas if multiple people are

affected Carbon monoxide is the most common toxic

gas unvented burning of fuel in the winter (particularly

during power outages as people try to stay warm) smoke inhalation from house fires suicide

Be aware of possible toxic gas in tunnels, silos, and other unvented locations

If large numbers of people are affected and circumstances are suspicious, be alert to the possibility of terrorism


Toxic GasesCarbon monoxide (CO) Odorless, colorless gas Found in products of combustion, such as those

produced by cars and trucks, small engines, stoves, burning charcoal, wood, gas ranges and heating systems.

Can build up in enclosed spaces Can also occur in structure fires Binds to the hemoglobin of red blood cells, impairing

oxygen carrying capacity Half-life of CO in the blood:

Room air: 240-360 minutes O2 (100%): 80 minutes Hyperbaric (high pressure) O2: 22 minutes


Toxic GasesCyanide (CN) Toxic compound often in the form of a gas

(hydrogen cyanide) Can be formed in the burning of plastics and

other materials (for example in house fires) Rare cases of industrial exposure, suicide, or

poisoning Cellular poison


Nerve AgentsNerve agents (organophosphates) Used in agriculture as insecticides (examples

include parathion, diazinon) Can be absorbed through skin or lungs, or

ingested Since WWII, have been used for chemical

warfare More recently have been used by terrorists

(sarin release in Tokyo subway) Occasional cases of suicide by ingesting

organophosphate pesticides Alters the transmission of nerve impulses by

affecting neurotransmitters throughout the body


Other Toxic Gases

Other toxic gases Methane, nitrogen dioxide may be

formed in sewers, silos, and other enclosed spaces

Chlorine, phosgene, and others may be released by industrial accidents

Presentation varies depending on type of gas; scene safety and ABCs are always indicated


Emergency care Ensure scene safety, remove the patient from the

exposed area ABCs, vitals Request ALS if indicated High flow oxygen Depending on the scenario, be prepared for multiple

patients (notify other responders, hospitals as soon as possible) Possible CN:

ALS may be able to administer a cyanide antidote

Possible nerve agent: Be prepared with suction

for massive secretions, vomiting, etc.

ALS may be able to administer a nerve agent antidote

Possible CO: If a CO monitoring is

available, obtain a reading from the structure or source, and the patient

Pulse oximeter readings are not reliable in CO poisoning!

Consider transport destination (the patient may benefit from hyperbaric oxygen)


Electrical Emergencies


Electric Shock Smaller doses of current (70–700 mA)

trigger ventricular fibrillation. Larger doses of current ( >1amp) cause

burns, tissue, cell damage. Type of current (DC vs. AC), current

pathway, and duration of current also influence the severity of injury: AC current generally causes more damage due to

tetanic stimulation and prolonged duration of exposure.

DC current is typically shorter duration, creating a single muscle spasm causing the victim to be thrown from the source.


Emergency Care Scene safety Do not touch any downed or active power lines, or

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

OK by qualified personnel. ABCs Provide full spinal stabilization Look for two burn sites: an entrance and exit site, these

may be in unpredictable locations, for example in one hand, out the other; in one hand, out the bottom of the foot, etc.

External wounds do NOT reflect the extent of injury Electricity can travel through blood vessels, muscle,

bone, doing damage as it goes


Lightning Responsible for approximately 50 deaths per

year in the US Estimates of several thousand injuries per year Lightning safety

Seek shelter indoors or in a car If trapped outdoors, avoid open fields, water, or

metal objects If indoors, stay off corded phones, don’t touch

metal/plumbing Cardiac arrest may occur; survival rates are

high if resuscitation is started promptly Major burns are uncommon Patients may suffer long-term neurologic

affects


Emergency Care Evacuate to a safe indoor location if

lightning is still in the area (30 min since last lightning strike is standard)

If trauma (fall, thrown a distance, etc.), provide spinal immobilization

ABCs and vitals Request ALS Defib protocols if patient is in cardiac arrest Cover burns, if any, with sterile dressing


Electrocution

Don’t go near downed power line

Entrance Wound - Dark spot in center of wound

Exit Wound – where body closest to ground


Summary: Heat and Cold Exposure

Heat cramps, heat exhaustion, & heatstroke are progressive phases of heat illness managed in the field by addressing dehydration and reducing core temperature

Four mechanisms cause heat loss: conduction, convection, radiation, & evaporation

Steps for prehospital emergency care for a hypothermic patient include: remove patient from cold environment, protect patient from heat loss, and provide oxygen


Summary: Water-Related Emergencies For drowning patients, safely remove

from water, stabilize c-spine if indicated, and follow general resuscitation guidelines Extended submersion time has a poor

overall outcome For diving emergencies, gather

significant history including depth of dive and length of time underwater Treat with high flow oxygen and ALS as

indicated Definitive treatment for any significant

diving emergency is recompression in a hyperbaric chamber


Summary: Bites and Stings Control bleeding, identify animal,

evaluate at ER of clinic For bee stings, remove stinger, request

ALS if indicated, consider epi-pen Hypotension, respiratory distress,

widespread hives Epi-pen administration request an ALS

eval


Summary: Toxic Gases

Scene safety! Determine type of exposure Carbon monoxide is the most

common (unvented burning of fuel, smoke inhalation from fires, etc.)

Also consider cyanide, organophosphates, others

Treatment: scene safety, high flow oxygen, ALS as indicated


Summary: Electrical Injuries

Electric shock can cause burns, tissue damage, and cardiac arrhythmias (particularly VF)

Lightning strike may also cause cardiac arrest

External wounds (burns) do not represent the extent of the internal damage

Treat with normal defib protocols after ensuring that the scene is safe

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BLS 2014: Environmental Emergencies. This course addresses: Cold and heat related emergencies ...

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