Transcript Document

Environmental
Emergencies
Sections
 Pathophysiology of Heat and Cold
Disorders
 Heat Disorders
 Cold Disorders
 Near-Drowning and Drowning
 Diving Emergencies
 High-Altitude Illness
 Nuclear Radiation
Environmental
Emergencies
 Risk Factors
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Age
Poor General Health
Fatigue
Predisposing Medical Conditions
Medications
 Homeostasis
 Tendency of the body to maintain a steady and normal
internal environment
Pathophysiology of Heat
and Cold Disorders
 Mechanisms of Heat Gain and
Loss
 Thermal Gradient
 Wind
 Relative Humidity
 Thermogenesis
 Work-Induced
 Thermoregulatory
 Diet-Induced
Pathophysiology of Heat
and Cold Disorders
 Thermolysis
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Conduction
Convection
Radiation
Evaporation
Respiration
Pathophysiology of Heat
and Cold Disorders
 Thermoregulation
 Body Temperature
 Core temperature
 Peripheral temperature
 The Hypothalmus
 Heat Dissipation
 Sweating, vasodilation
 Heat Conservation
 Shivering,
vasoconstriction
Pathophysiology of Heat
and Cold Disorders
 Thermoreceptors
 Peripheral thermoreceptors
 Central thermoreceptors
 Metabolic Rate
 Basic metabolic rate
 Exertional metabolic rate
 Core temperature measurement
Heat Disorders
 Hyperthermia
 Signs of Thermolysis
 Diaphoresis, increased skin temperature
 Signs of Thermolytic Inadequacy
 Altered mentation or altered level of consciousness
 Manifestations
 Heat cramps
 Heat exhaustion
 Heat stroke
Heat Disorders
 Predisposing Factors
 Age of the Patient
 Health of the Patient
 Medications
 Diuretics, beta-blockers, psychotropics, and
antihistamines
 Level of Acclimatization
 Length and Intensity of Exposure
 Environmental Factors
Heat Disorders
 Preventive Measures
 Maintain adequate fluid intake.
 Allow time for gradual acclimatization.
 Limit exposure to hot environments.
Heat Disorders
Heat Cramps
Heat Exhaustion
Heatstroke
Role of Dehydration
in Heat Disorders
 Close Relationship to Heat Disorders
 Dehydration prevents thermolysis.
 Signs & Symptoms
 Nausea, vomiting, and abdominal distress
 Vision disturbances, decreased urine output
 Poor skin turgor and signs of hypovolemic shock
 Treatment
 Oral fluids if the patient is alert and oriented
 IV fluids if the patient has an altered mental status or
is nauseated
Fever (Pyrexia)
 Pyrogens
 Differentiating Fever from
Heatstroke
 Cooling the Fever Patient
 Consider antipyretic medication.
 Acetaminophen or ibuprofen
 Avoid sponge baths.
Cold Disorders
 Hypothermia
 Mechanisms of Heat Conservation
and Loss
 Predisposing Factors
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Age of the Patient
Health of the Patient
Medications
Prolonged or Intense Exposure
Coexisting Weather Conditions
Cold Disorders
 Preventative Measures
 Dress warmly and ensure plenty of rest.
 Eat appropriately or at regular intervals.
 Limit exposure to cold environments.
 Degrees of Hypothermia
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Mild
Severe
Compensated Hypothermia
Acute, Subacute, and Chronic Exposure
Cold
Disorders
Hypothermia
 Signs & Symptoms
 Mild
 Severe
Hypothermia
 ECG
 Pathognomonic J waves (Osborn waves).
 Eventual onset of bradycardia.
 Ventricular fibrillation probable below 86º F.
Hypothermia
Hypothermia
 Treatment
 Active Rewarming
 Active external rewarming
 Active internal rewarming
 Rewarming Shock
 Cold Diuresis
Hypothermia
 Resuscitation
 BCLS
 Perform pulse and respiration checks for longer periods.
 Administer up to 3 shocks with the AED.
 Follow with CPR, rewarming, and rapid transport.
 ACLS
 Intubate and administer up to 3 shocks and initial
medications.
 Establish IV access, begin rewarming, and transport
rapidly.
 Avoid further resuscitation until the core temperature
is above 86º F.
Frostbite
 Superficial
Frostbite
 Freezing of
epidermal tissue
 Redness followed
by blanching and
diminshed
sensation
 Deep Frostbite
 Freezing of
epidermal and
subcutaneous
layers
 White, frozen
appearance
Frostbite
 Treatment
 Do not thaw the affected area if there is the possibility
of refreezing.
 Do not massage the affected area.
 Administer analgesia prior to thawing.
 Transport; rewarm by immersion only if transport is
lengthy or delayed.
 Cover the thawed part with a loose, sterile dressing.
 Elevate and immobilize the thawed part.
 Do not puncture or drain blisters.
 Do not rewarm feet if walking will be required.
Trench Foot
 Trench Foot
 Occurs above freezing.
 Typically occurs from standing in cold water.
 Symptoms are similar to frostbite.
 Pain may be present, and blisters may form with
spontaneous rewarming.
 Treatment:
 Warm, dry, and aerate the feet.
 Prevention is the best treatment.
Near-Drowning
and Drowning
 Near-Drowning vs. Drowning
 Pathophysiology of Drowning and
Near-Drowning
 Dry vs. Wet Drowning
 Fresh-Water vs. Saltwater Drowning
 Fresh water causes the alveoli to collapse from a
lack of surfactant.
 Salt water causes pulmonary edema and eventual
hypoxemia due to its hypertonic nature.
Near-Drowning
and Drowning
Near-Drowning
and Drowning
 Factors Affecting Survival
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Cleanliness of Water
Length of Time Submerged
Victim’s Age and General Health
Water Temperature
 Cold-water drowning.
 Mammalian diving reflex.
 The cold-water drowning patient is not dead until
he is warm and dead.
Near-Drowning
and Drowning
 Treatment for Near-Drowning
 Remove the patient from the water.
 Attempt rescue only if properly trained and equipped.
 Initiate ventilation while the patient is still in the water.
 Suspect head and neck injury if the patient
experienced a fall or was diving. Place the victim on a
long spine board and use c-spine precautions
throughout care.
 Protect the patient from heat loss.
 Evaluate ABCs. Begin CPR and defibrillation if
indicated.
Near-Drowning
and Drowning
 Manage the airway using proper suctioning and airway
adjuncts.
 Administer oxygen at 100% concentration.
 Use respiratory rewarming, if available.
 Establish IV of lactated Ringer’s or normal saline at
75 mL/hr.
 Follow ACLS protocols if the patient is normothermic.
Treat hypothermic patients according to hypothermia
guidelines.
 Adult Respiratory Distress Syndrome
Diving Emergencies
 Scuba
 The Effects of Air Pressure on Gases
 Boyle’s Law
 The volume of a gas is inversely proportional to its
pressure if the temperature is kept constant.
 Dalton’s Law
 The total pressure of a mixture of gases is equal to the
sum of the partial pressures of the individual gases.
 Henry’s Law
 The amount of gas dissolved in a given volume of liquid
is proportional to the pressure of the gas above it.
Diving Emergencies
 Pathophysiology of Diving
Emergencies
 Increased dissolution of gases during descent due to
Henry’s law.
 Boyle’s law dictates that these gases have a smaller
volume.
 In a controlled ascent, the process is reversed and the
gases escape through respiration.
 A rapid ascent causes gases to come out of solution
quickly, forming gas bubbles in the blood, brain,
spinal cord, skin, inner ear, muscles, and joints.
Diving Emergencies
 Classification of Diving Emergencies
 Injuries on the Surface
 Injuries During Descent
 Barotrauma
 Injuries on the Bottom
 Nitrogen narcosis
 Injuries During Ascent
 Decompression illness
 Pulmonary overpressure and subsequent arterial gas
embolism, pneumomediastinum, or pneumothorax
Diving Emergencies
 General Assessment of Diving
Emergencies
 Time at Which Signs and Symptoms
Appeared
 Type of Breathing Apparatus Used
 Type of Hypothermia-Protective Garment
Worn
 Parameters of the Dive
 Number of dives, depth, and duration
 Aircraft Travel following a Dive
Diving Emergencies
 Factors to Assess
 Rate of Ascent
 Associated with panic forcing a rapid ascent
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Inexperience of the Diver
Improper Functioning of Depth Gauge
Previous Medical Diseases
Old Injuries
Previous Episodes of Decompression Illness
Use of Alcohol or Medications
Pressure Disorders
 Decompression Illness
 May occur with dives of 33’ or
more.
 Signs & Symptoms
 Occur within
36 hours.
 Joint/abdominal
pain.
 Fatigue,
paresthesias,
and CNS
disturbances.
 Treatment
 Recompression.
Pressure Disorders
 Treatment
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Assess ABCs and begin CPR if required.
Administer high-flow oxygen and intubate if indicated.
Maintain supine position.
Protect the patient from heat, cold, wetness, or noxious
fumes.
Transport and establish IV access.
Consult with medical direction regarding administration
of dexamethasone, heparin, or diazepam if CNS is
involved.
If aeromedical evacuation is used, maintain cabin
pressure at sea level or fly at the lowest possible altitude.
Send diving equipment with the patient for analysis if
possible.
Pressure Disorders
 Pulmonary Overpressure
Accidents
 Can occur in depths as shallow as 6’.
 Signs & Symptoms
 Substernal chest pain with associated respiratory
distress and diminished breath sounds
 Treatment
 Treat as a pneumothorax.
 Provide rest and supplemental oxygen.
Pressure Disorders
 Arterial Gas Embolism
 Signs & Symptoms
 Onset is within 2–10 minutes of ascent .
 There is dramatic onset of sharp, tearing pain.
 Common presentation mimics a stroke; suspect AGE in
any patient with neurological deficits immediately after
ascent.
 Treatment
 Assess ABCs, provide high-flow oxygen.
 Maintain a supine position; monitor vital signs frequently.
 Establish IV access and consider administering
corticosteroids.
 Rapidly transport to a recompression chamber.
Pressure Disorders
 Pneumomediastinum
 Signs & Symptoms
 Substernal chest pain, irregular pulse, abnormal
heart sounds, hypotension with a narrow pulse
pressure, and a change in voice
 Treatment
 Provide high-flow oxygen.
 Establish IV access.
 Transport for further evaluation.
Pressure Disorders
 Nitrogen Narcosis
 Occurs during a dive.
 Can contribute to accidents during the dive.
 Signs & Symptoms
 Altered levels of consciousness and impaired
judgment.
 Treatment
 Return to shallow depth.
 Use oxygen/helium mix during dive.
Diving Emergencies
 Other Diving-Related
Emergencies
 Oxygen Toxicity
 Hypercapnia
 Diver’s Alert Network
 Consultation and Referrals
 (919) 684-8111
High-Altitude Illness
 Manifestation
 Altitudes above 8,000’
 Prevention
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Ascend gradually.
Limit exertion.
Descend for sleep.
Eat a high-carbohydrate diet.
Medications
 Acetazolamide and nifedipine
High-Altitude Illness
 Types of High-Altitude Illness
 Acute Mountain Sickness
 Mild cases include lightheadedness,
breathlessness, weakness, headache, nausea, and
vomiting.
 Severe cases include weakness, severe vomiting,
decreased urine output, shortness of breath, and
an altered level of consciousness.
 Treatment includes halting of ascent or descent,
use of acetazolamide and antinausea drugs and
supplemental oxygen.
High-Altitude Illness
 High-Altitude Pulmonary Edema
 Mild symptoms include dry cough, shortness of
breath, and slight crackles in the lungs.
 Severe cases develop cyanosis, dyspnea, frothy
sputum, weakness, and possibly coma or death.
 Treatment includes descent and supplemental
oxygen, or portable hyperbaric bag; medications
such as acetazolamide, nifedipine, and lasix may be
useful also.
High-Altitude Illness
 High-Altitude Cerebral Edema
 Usually occurs as progression of AMS or HAPE.
 Symptoms include altered mental status, ataxia,
decreased level of consciousness, and coma.
 Treatment includes descent and supplemental
oxygen, or portable hyperbaric bag.
Nuclear Radiation
 Personal Safety
 Only appropriately trained and equipped
personnel should handle radiation
emergencies.
 Basic Nuclear Physics
 Atoms
 Protons, neutrons, and electrons
 Isotopes and Half-Life
 Ionizing radiation
Nuclear Radiation
 Ionizing Radiation
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Alpha particles
Beta particles
Gamma rays
Neutrons
 Effects of Radiation on the Body
 Detection of Radiation
 RAD and REM
 Acute and Long-Term Effects
Nuclear Radiation
Nuclear Radiation
 Principles of
Safety
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Time
Distance
Shielding
Clean Accidents
 Patient is exposed but
not contaminated.
 Dirty Accidents
 Patient is
contaminated by
radioactive particles,
liquids, gases ,or
smoke.
Nuclear Radiation
 Management
 Park upwind.
 Look for signs of
radioactive
exposure.
 Use portable
instruments to
detect radioactivity.
 Normal emergency
care principles
should be applied.
 Externally radiated
and internally
contaminated
patients pose little
danger.
 Externally
contaminated
patients require
decontamination.
Environmental
Emergencies
 Pathophysiology of Heat and Cold
Disorders
 Heat Disorders
 Cold Disorders
 Near-Drowning and Drowning
 Diving Emergencies
 High-Altitude Illness
 Nuclear Radiation