Transcript document

Chapter 10
Environmental Emergencies
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Topics
Pathophysiology of Heat and Cold
Disorders
Heat Disorders
Cold Disorders
Near-Drowning and Drowning
Diving Emergencies
High-Altitude Illness
Nuclear Radiation
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
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
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Pathophysiology of
Heat and Cold Disorders (1 of 4)
Mechanisms of Heat Gain and Loss
– Thermal Gradient
Wind
Relative humidity
Thermogenesis
– Work-Induced
– Thermoregulatory
– Diet-Induced
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Pathophysiology of
Heat and Cold Disorders (2 of 4)
Thermolysis
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Conduction
Convection
Radiation
Evaporation
Respiration
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Pathophysiology of
Heat and Cold Disorders (3 of 4)
Thermoregulation
– Body Temperature
Core temperature
Peripheral temperature
– The Hypothalamus
– Heat Dissipation
Sweating, vasodilation
– Heat Conservation
Shivering,
vasoconstriction
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Pathophysiology of
Heat and Cold Disorders (4 of 4)
Thermoregulation (cont.)
– Thermoreceptors
Peripheral thermoreceptors
Central thermoreceptors
– Metabolic Rate
Basic metabolic rate
Exertional metabolic rate
Core temperature measurement
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Heat Disorders (1 of 4)
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
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Heat Disorders (2 of 4)
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
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Heat Disorders (3 of 4)
Preventive Measures
– Maintain adequate fluid intake.
– Allow time for gradual acclimatization.
– Limit exposure to hot environments.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Heat Disorders (4 of 4)
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Heat Cramps
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Heat Exhaustion
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Heatstroke
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Role of Dehydration
in Heat Disorders
Close Relationship to Heat Disorders
– Dehydration prevents thermolysis.
Signs and 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
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Fever (Pyrexia)
Pyrogens
Differentiating Fever from Heatstroke
Cooling the Fever Patient
– Consider antipyretic medication.
Acetaminophen or ibuprofen
– Avoid sponge baths.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Cold Disorders (1 of 3)
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
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Cold Disorders (2 of 3)
Preventive 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
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Cold Disorders
(3 of 3)
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Hypothermia (1 of 5)
Signs and Symptoms
– Mild
– Severe
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Hypothermia (2 of 5)
ECG
– Pathognomonic J waves (Osborn waves)
– Eventual onset of bradycardia
– Ventricular fibrillation probable below 86º F
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Hypothermia
(3 of 5)
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Hypothermia (4 of 5)
Treatment
– Active Rewarming
Active external rewarming
Active internal rewarming
– Rewarming Shock
– Cold Diuresis
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Hypothermia (5 of 5)
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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Frostbite (1 of 2)
Superficial Frostbite
– Freezing of epidermal
tissue
– Redness followed by
blanching and
diminished sensation
Deep Frostbite
– Freezing of epidermal
and subcutaneous
layers
– White, frozen
appearance
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Frostbite (2 of 2)
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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Near-Drowning
and Drowning (1 of 3)
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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Near-Drowning
and Drowning (2 of 3)
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Near-Drowning
and Drowning (3 of 3)
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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Near-Drowning (1 of 2)
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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Near-Drowning (2 of 2)
Treatment (cont.)
– 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
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Diving Emergencies (1 of 5)
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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Diving Emergencies (2 of 5)
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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Diving Emergencies (3 of 5)
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
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Diving Emergencies (4 of 5)
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
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Diving Emergencies (5 of 5)
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
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Pressure Disorders (1 of 6)
Decompression Illness
– May occur with dives of 33’ or more
– Signs and Symptoms
Occur within
36 hours
Joint/abdominal
pain
Fatigue,
paresthesias,
and CNS
disturbances
– Treatment
Recompression
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Pressure Disorders (2 of 6)
Treatment
– Assess ABCs and begin CPR if required.
– Administer high-flow, high-concentration 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 air 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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Pressure Disorders (3 of 6)
Pulmonary Overpressure Accidents
– Can occur in depths as shallow as 6’
– Signs and Symptoms
Substernal chest pain with associated
respiratory distress and diminished breath
sounds
– Treatment
Treat as a pneumothorax.
Provide rest and supplemental oxygen.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Pressure Disorders (4 of 6)
Arterial Gas Embolism
– Signs and 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, high-concentration
oxygen.
Maintain a supine position; monitor vital signs
frequently.
Establish IV access and consider administering
corticosteroids.
Rapidly transport to a recompression chamber.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Pressure Disorders (5 of 6)
Pneumomediastinum
– Signs and Symptoms
Substernal chest pain, irregular pulse,
abnormal heart sounds, hypotension with a
narrow pulse pressure, and a change in
voice.
– Treatment
Provide high-flow, high-concentration oxygen.
Establish IV access.
Transport for further evaluation.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Pressure Disorders (6 of 6)
Nitrogen Narcosis
– Occurs During a Dive
Can contribute to accidents during the dive.
– Signs and Symptoms
Altered levels of consciousness and impaired
judgment.
– Treatment
Return to shallow depth.
Use oxygen/helium mix during dive.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Diving Emergencies
Other Diving-Related Emergencies
– Oxygen Toxicity
– Hypercapnia
Diver’s Alert Network
– Consultation and Referrals
(919) 684-8111
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
High-Altitude Illness (1 of 4)
Manifestation
– Altitudes above 8,000 feet
Prevention
–
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Ascend gradually.
Limit exertion.
Descend for sleep.
Eat a high-carbohydrate diet.
Medications:
Acetazolamide and nifedipine
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
High-Altitude Illness (2 of 4)
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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
High-Altitude Illness (3 of 4)
High-Altitude Pulmonary Edema (HAPE)
– 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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
High-Altitude Illness (4 of 4)
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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Nuclear Radiation (1 of 5)
Personal Safety
– Only appropriately trained and equipped
personnel should handle radiation
emergencies.
Basic Nuclear Physics
– Atoms
Protons, neutrons, and electrons
– Isotopes and Half-Life
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Nuclear Radiation (2 of 5)
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
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Nuclear Radiation (3 of 5)
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Nuclear
Radiation (4 of 5)
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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Nuclear Radiation (5 of 5)
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.
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ
Summary
Pathophysiology of Heat and Cold
Disorders
Heat Disorders
Cold Disorders
Near-Drowning and Drowning
Diving Emergencies
High-Altitude Illness
Nuclear Radiation
Bledsoe et al., Paramedic Care Principles & Practice Volume 3: Medical
© 2006 by Pearson Education, Inc. Upper Saddle River, NJ