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Chapter 40
Environmental
Emergencies
Copyright (c) The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
40-1
Objectives
40-2
Body Temperature
• Balance between heat produced and
heat lost
• Measured in degrees
• Core temperature
• Peripheral (surface) temperature
40-3
Temperature Regulation
• Skin
– Sensors detect changes in temperature
• Hypothalamus
– Located in the brain
– Functions as the body’s thermostat
40-4
Temperature Regulation
• When high temperatures
are sensed:
– Blood vessels in the skin
widen (dilate)
40-5
Temperature Regulation
• When low temperatures
are sensed:
– Blood vessels in the skin
narrow (constrict)
– Sweating stops
– Major body muscles shiver
to increase heat
40-6
Heat Production
• Heat is mainly produced
by:
– Converting food to
energy (metabolism)
– Increasing skeletal
muscle activity
40-7
Heat Loss
40-8
Radiation
• Transfer of heat from one
object to another without
contact between the two
objects
• Example:
– Heat from the sun
40-9
Convection
• Transfer of heat by
the movement of air
or water current
40-10
Conduction
• Transfer of heat between
objects that are in direct
contact
• Amount of heat lost depends
on:
– Temperature difference between
the body and the object
– Amount of time the body and the
objects are in contact
– Amount (surface area) of the
body in contact with the object
40-11
Evaporation
• Loss of heat by vaporization
of moisture on the body
surface
– Body heat is lost if the skin
temperature is higher than the
surrounding temperature
– Body heat is gained if the
surrounding air temperature
is higher than the body
temperature
40-12
Respiration
• Small amount of heat is lost through
the evaporation of moisture within the
lungs
40-13
Mechanisms of Heat Loss
• Peripheral blood vessels dilate
• Blood flow to body surface increases
• Heat escapes from the skin surface by
radiation and conduction
• When air currents pass across the skin,
heat is lost by convection
• Sweating allows heat loss through
evaporation
40-14
Types of Cold Emergencies
40-15
Types of Cold Emergencies
• Two main types of cold emergencies:
– Generalized cold emergency
• Generalized hypothermia
– Local cold injury
• Damage to a specific area of the body
40-16
Hypothermia
• Core body temperature of less than
95°F (35°C)
• Three stages:
1. Mild hypothermia (core body temperature
93.2° to 96.8°F, or 34.0° to 37.0°C)
2. Moderate hypothermia (86.0° to 93.1°F, or
30.0° to 33.9°C)
3. Severe hypothermia (less than 86°F, or
less than 30.0°C)
40-17
Hypothermia
• Can occur even in warm weather
• Can occur when the body loses its
ability to maintain a normal body
temperature
40-18
Factors Contributing to Hypothermia
• Ambient temperature,
wind speed, moisture
• Prolonged exposure to
a cool environment
• Activity level of victim
• Immersion in water
• Improper, inadequate,
or wet clothing
• Low body weight
• Poor physical condition
• Low blood sugar
• Alcohol/drug ingestion
• Extremes in age (very
young children, older
adults)
• Impaired judgment due to
mental illness or
Alzheimer's disease
• Preexisting illness or
injury
• Suicide
• Previous cold exposure
40-19
Scene Size-Up
• Signs of exposure may be obvious or
subtle
• Signs of a subtle exposure include:
– Alcohol ingestion
– Underlying illness
– Overdose or poisoning
– Major trauma
– Outdoor recreation
– Decreased room temperature
40-20
Scene Size-Up
• Remove the patient from the
environment
– Use trained rescuers when necessary
40-21
Primary Survey
•
•
•
•
Form a general impression
Move the patient to a warm location
Remove any cold or wet clothing
Protect the patient from the
environment
• Cover the patient to preserve body heat
• Stabilize the patient’s spine if needed
40-22
Primary Survey
• Assess:
– Mental status
– Airway
– Breathing
– Circulation
40-23
Vital Signs
• Breathing
– Initially increased
– Then slow and
shallow
– Finally, absent
• Heart rate
– Initially increased
– Then slow and
irregular
– Finally, absent
• Skin
– Initially red
– Then pale
– Then blue
– Finally, gray,
hard, and cold to
the touch
40-24
Motor and Sensory Functions
•
•
•
•
•
Joint aches
Muscle stiffness
Lack of coordination
Staggering walk
Shivering usually present initially
– May decrease until it is absent
40-25
Mild Hypothermia
•
•
•
•
•
•
•
Increased heart rate
Increased respiratory rate
Cool skin
Shivering
Difficulty talking, slurred speech
Difficulty moving
Memory lapse (amnesia), mood
changes, combative attitude
• Joint aches, muscle stiffness
• Altered mental status, confusion,
or poor judgment
40-26
Moderate Hypothermia
• Shivering that may gradually decrease and
become absent
• Decreasing heart rate and respiratory rate
• Irregular heart rate
• Pale, blue (cyanotic), or mottled skin
• Progressive loss of
responsiveness
• Dilated pupils
• Blood pressure that is
difficult to obtain
40-27
Severe Hypothermia
• Irrational attitude that changes
to unresponsiveness
• Rigid muscles
• Cold skin
• Blue or mottled skin
• Slow or absent breathing
• Slowly responding pupils
• Slow, irregular, or absent heart
rate
• A pulse that is hard to feel or
absent
• Low to absent blood pressure
• Cardiopulmonary arrest
40-28
History
• Obtain SAMPLE history
• Ask the following questions:
– How long has the patient been
exposed to the cold?
– What was the source of the
cold (water, snow)?
– If exposed to water,
approximate water
temperature?
– What was the patient doing
when his symptoms began?
40-29
Emergency Care for Hypothermia
• Remove the patient from the cold
environment
• Protect the patient from the cold and drafts
– Use sleeping bag, blankets, newspapers, etc.
– Place insulating material between patient and
the surface on which he is lying
40-30
Emergency Care for Hypothermia
• Avoid rough handling
• Do not allow the patient to walk or exert
himself
• Maintain an open airway
• Have suction available
• Give oxygen
• Begin CPR if needed
40-31
Emergency Care for Hypothermia
• Passive rewarming
– Placing the patient in a warm environment
– Applying warm clothing and blankets
– Preventing drafts
40-32
Emergency Care for Hypothermia
• Active rewarming
– Involves adding heat directly to the
surface of the patient’s body
– May be used if the patient is alert and
responding appropriately
– Should not delay definitive care
– Important: Consult medical direction
40-33
Emergency Care for Hypothermia
• Do not allow the patient to eat or drink
stimulants or to drink alcohol
• Do not rub or massage the patient’s
extremities
• During transport, turn the heat up in the
patient area of the ambulance
40-34
Local Cold Injury
40-35
Local Cold Injury
• Also called frostbite
• Involves tissue damage
to a specific area of
the body
• Occurs when a body part
is exposed to prolonged
or intense cold
• Cold causes narrowing of
blood vessels in affected part
– Reduces blood flow to affected area
40-36
Local Cold Injury
Risk Factors
• Circulation problems
• Use of alcohol, nicotine, and some
medications
• Burn or previous cold injury
• Ambient temperature
• Wind-chill factor
• Length of exposure
• Type and number of clothing layers worn
• Whether or not patient is wet
• Whether or not patient has had direct
contact with cold objects
40-37
Superficial Cold Injury
• Involves the uppermost skin layers
• Skin of the exposed area first appears
red and inflamed
– With continued cooling, the area becomes
gray or white
• Patient may complain of a loss of
feeling in the injured area
40-38
Deep Cold Injury
• Involves more tissue layers
• Whitish skin color is followed by a
waxy appearance
• Affected area becomes
frozen
• Swelling may be present
• Blisters may be present
40-39
Emergency Care for
Local Cold Injury
• Scene size-up
• Remove patient from the cold
environment
• Protect the affected area from further
injury
• Give oxygen if indicated
40-40
Emergency Care for
Superficial Cold Injury
[Insert figure 40-3]
40-41
Emergency Care for
Deep Cold Injury
• Do not break blisters
• Do not rub or massage the affected area
• Do not apply heat to or rewarm the
affected area
• Do not allow the patient to walk on an
affected extremity
40-42
Local Cold Injury
Rewarming
• Handle affected area gently
• Immerse affected area in a warm water
bath
– Do NOT
use
hot water
40-43
Local Cold Injury
Rewarming
• Continue rewarming until the affected part is
soft and color and sensation return
• Gently dry the area after rewarming
• Dress the area with dry, sterile dressings
[Insert figure 40-5]
40-44
Exposure to Heat
40-45
Exposure to Heat
• Hyperthermia
– High core body temperature
– Body gains or produces more heat
than it loses
• Three main types of heat
emergencies:
– Heat cramps
– Heat exhaustion
– Heat stroke
40-46
Predisposing Factors
• High ambient
temperature
• High relative
humidity
• Elderly
• Newborns,
infants
• Medications
– Amphetamines
– Cocaine
– Alcohol
– Tricyclic
antidepressants
– Antihistamines
40-47
Types of Heat-Related Emergencies
• Heat Cramps
• Heat Exhaustion
• Heat Stroke
40-48
Heat Cramps
• Results from water and electrolytes lost
during sweating
– Leads to dehydration
• Loss of water and electrolytes causes
painful muscle spasms
– Arms, abdomen, back of lower legs
40-49
Heat Exhaustion
• Cool, pale, moist
• Result of excessive
skin
heat and dehydration
• Muscle cramps
• Oral body
• Heavy sweating
temperature normal • Fast heart rate
or slightly elevated
• Thirst
(up to 101° to 102°F
• Dizziness
or 38.3° to 38.9°C)
• Tiredness
• Weakness
• May progress to heat • Headache
stroke if not treated • Nausea, vomiting
• Fainting
40-50
Heat Stroke
• Medical emergency
• Very high body
temperature
– Higher than 103°F or
39.4°C, orally
• Act quickly to lower
patient’s body
temperature
• Altered mental status
• Dry, hot, flushed skin
• Fast heart rate initially,
then a slow heart rate
• Headache
• Dizziness
• Nausea
• Vision disturbances
• Muscle twitching,
seizures
• Unresponsiveness
40-51
Emergency Care for Heat-Related Injuries
• Remove patient from hot environment
• If the patient has moist, pale, skin that is
normal to cool in temperature:
– Place patient in supine position
– Give oxygen if indicated
– Remove outer clothing
– Consult medical direction
40-52
Emergency Care for Heat-Related Injuries
• Remove patient from hot environment
• If the patient has hot and dry or moist
skin:
– Call for ALS personnel
right away
– Give oxygen if indicated
– Remove outer clothing
– Cool the patient
– Immediate transport
[Insert figure 40-7]
40-53
Water-Related Emergencies
40-54
Terms
• Drowning
• Delayed drowning
• Immersion
• Submersion
40-55
Drowning
Risk Factors
•
•
•
•
•
•
•
•
Age
Gender
Race
Inability to swim
Use of drugs, alcohol
Underlying illness or injury
Child abuse, suicide, or homicide
Hypothermia
40-56
Effects of Drowning
•
•
•
•
•
•
•
•
•
Panic
Hyperventilation
Gastric distention
Mammalian diving reflex
Hypoxia
Aspiration
Wet drowning
Laryngospasm
Dry drowning
40-57
Factors That Influence a Drowning
Victim’s Chances for Survival
• Length of immersion/
submersion
• Duration of hypoxia
• Ability to swim
• Age of victim
• Cleanliness of the
water
• Temperature of the
water
• Duration and degree
of hypothermia
• Preexisting medical
conditions
• Presence of drugs
and/or alcohol
• Presence of
associated injuries
• Response to initial
resuscitation efforts
40-58
Scene Safety
• Study the scene
– Determine if approaching the
patient is safe
– Evaluate the mechanism of injury
• Obtain additional help before
contact with the patient(s)
• Call for specially trained
personnel as needed
40-59
Drowning
Special Considerations
• Suspect neck injury:
– When the mechanism of injury is unknown
– When signs of facial trauma are present
– When signs of drug or alcohol use are
present
– In incidents involving use of a water slide
– Swimming, boating, water-skiing, or diving
accidents
40-60
Drowning
Signs and Symptoms
• Signs and symptoms vary
• Nervous system
• Respiratory system
• Cardiovascular system
40-61
Establish Patient Priorities
• Priority patients include:
• Patients who give a poor general
impression
• Patients experiencing difficulty breathing
• Patients with signs and symptoms of
shock
• Unresponsive patients with no gag reflex
or cough
• Responsive patients who are unable to
follow commands
40-62
Secondary Survey
• Physical exam
– Look for other injuries
• SAMPLE history
• Vital signs
40-63
Emergency Care for Drowning
• Scene safety
• Spinal stabilization, if indicated
• Give oxygen if indicated
• Suction ready
• Rescue breathing, CPR / AED as
needed
• Prompt transport
40-64
Diving Emergencies
40-65
Barotrauma
• Diving-related injury caused by
pressure
• Can occur on ascent or descent
– Ascent
• Pulmonary overpressurization syndrome
(POPS) or "burst lung"
– Descent
• “Lung squeeze" or "the squeeze"
40-66
Emergency Care for Barotrauma
• Establish and maintain an open airway
• Give oxygen by nonrebreather mask
• Transport promptly
40-67
Air Embolism
• May occur when:
– Divers ascend too rapidly
– Divers hold their breath during ascent
• Onset is usually rapid and dramatic
• Air bubbles become lodged in small
arteries, cutting off circulation
40-68
•
•
•
•
•
Air Embolism
Signs and Symptoms
Dizziness
• Sudden
unresponsiveness
Confusion
• Pink, frothy sputum
Shortness of
breath
• Respiratory arrest
Visual
• Cardiac arrest
disturbances
Weakness or
paralysis in
extremities
40-69
Emergency Care for Air Embolisms
• Establish and maintain an open airway
• Give oxygen
• Position on left side with head and
chest tilted downward
– If no contraindications
– If approved by medical direction
• Maintain body temperature
• Consider transport to recompression
facility
40-70
Decompression Sickness (Bends)
• Results from dissolved nitrogen in
blood and tissues
• Size and location of nitrogen bubbles
determines signs and symptoms
40-71
Decompression Sickness (Bends)
• Fatigue
• Weakness
• Shortness of
breath
• Skin rash
• Itching
• Joint soreness
•
•
•
•
•
Dizziness
Headache
Paralysis
Seizures
Unresponsiveness
40-72
Emergency Care for
Decompression Sickness
• Establish and maintain an open airway
• Give oxygen
• Position on left side with head and
chest tilted downward
– If no contraindications
– If approved by medical direction
• Maintain body temperature
• Consider transport to recompression
facility
40-73
Bites and Stings
40-74
Pit Vipers
40-75
Pit Viper Bites
Signs and Symptoms
A rattlesnake bite six hours after
the injury.
Same patient seven weeks
after the rattlesnake bite.
40-76
Pit Viper Bites
Signs and Symptoms
Local
Systemic
• Fang marks or
semicircle of teeth
marks
• Burning pain
• Red and swollen
area around the
fang or teeth marks
• Discoloration and
blisters common
•
•
•
•
Weakness
Sweating
Nausea and vomiting
Shock
40-77
Coral Snakes
[Insert figure 40-13]
40-78
Early
Coral Snake Bites
Signs and Symptoms
Late
• Scratch marks or tiny
puncture marks
• Little or no pain at
site
• Minimal to moderate
swelling
• Slurred speech
• Muscle weakness
• Difficulty swallowing
• Dilated pupils
•
•
•
•
•
Nausea/vomiting
Difficulty breathing
Seizures
Paralysis
Respiratory failure
40-79
Emergency Care for Snakebites
• Ensure safety of all rescuers
• It is not necessary to capture the snake
for identification
• Establish and maintain an open airway
• Give oxygen if indicated
• Keep the patient calm
• Limit patient’s physical activity
• Remove rings, watches, and tight
clothing from the injured area before
swelling begins
40-80
Emergency Care for Snakebites
• Pressure immobilization technique
[Insert figure 40-15]
40-81
Emergency Care for Snakebites
• Monitor swelling
[Insert figure 40-16]
40-82
Emergency Care for Snakebites
• Do not apply heat or cold to the bite site
• Do not cut the wound
• Do not attempt to suck out the venom
• Do not apply a constricting band or
tourniquet
40-83
Arthropods
•
•
•
•
•
•
Spiders
Insects
Crustaceans
Scorpions
Lice
Fleas
•
•
•
•
•
•
Ticks
Bedbugs
Horseshoe crabs
Centipedes
Millipedes
Mites
40-84
Black Widow Spider
40-85
Brown Recluse Spider
40-86
Emergency Care for Spider Bites
•
•
•
•
Maintain an open airway, give oxygen
Gently wash the area
Remove jewelry from injured area
If swelling present, mark outer edge
and note the time with a pen or marker.
• Observe closely for development of
allergic reaction; treat as needed
• Transport
40-87
Scorpion Stings
40-88
Emergency Care for Scorpion Stings
•
•
•
•
•
Maintain an open airway
Give oxygen
Gently wash the area
Remove jewelry from injured area
If swelling present, mark outer edge
and note the time with a pen or marker
• Observe closely for development of
allergic reaction; treat as needed
• Transport
40-89
Hymenoptera Stings
(Bees, Wasps, and Ants)
40-90
Emergency Care for Hymenoptera Stings
• Maintain an open airway, give oxygen if
indicated
• Remove stinger by scraping with flat
edge
• Remove jewelry from injured area
• If swelling present, mark outer edge
and note the time with a pen or marker.
• Observe closely for development of
allergic reaction; treat as needed
40-91
• Transport
Marine Life Stings
[Insert figures 40-27]
40-92
Emergency Care for
Venomous Marine Injuries
• Maintain an open airway, give oxygen
• Stingray injury
– Flush wound immediately
– Immerse injured part in hot water to
patient tolerance (109° to 113°F, or
43° to 45°C) for 30 to 90 minutes
– Elevate injured arm or leg
– Cover wound with a sterile dressing
• Transport
40-93
Dog and Cat Bites
[Insert figure 40-28]
40-94
Emergency Care for Dog and Cat Bites
•
•
•
•
•
•
Maintain an open airway
Give oxygen
Control bleeding
If no bleeding, gently wash the area
Remove jewelry from injured area
If swelling present, mark outer edge
and note the time with a pen or marker.
• Transport
40-95
Human Bites
• Usually occur while playing or fighting
• Clenched fist injury
– Also called a fight bite
– Most serious human bite
– Infection common
40-96
Emergency Care for Human Bites
•
•
•
•
•
•
Maintain an open airway
Give oxygen if indicated
Control bleeding
If no bleeding, gently wash the area
Remove jewelry from injured area
If swelling present, mark outer edge
and note the time with a pen or marker.
• Transport
40-97
Questions?
40-98