1. Environmental
Emergencies

2. Sections
 Pathophysiology of Heat and Cold
Disorders
 Heat Disorders
 Cold Disorders
 Near-Drowning and Drowning
 Diving Emergencies
 High-Altitude Illness
 Nuclear Radiation

3. Environmental
Emergencies
 Risk Factors
 Age
 Poor General Health
 Fatigue
 Predisposing Medical Conditions
 Medications
 Homeostasis
 Tendency of the body to maintain a steady and normal
internal environment

4. Pathophysiology of Heat
and Cold Disorders
 Mechanisms of Heat Gain and
Loss
 Thermal Gradient
 Wind
 Relative Humidity
 Thermogenesis
 Work-Induced
 Thermoregulatory
 Diet-Induced

5. Pathophysiology of Heat
and Cold Disorders
 Thermolysis
 Conduction
 Convection
 Radiation
 Evaporation
 Respiration

6. Pathophysiology of Heat
and Cold Disorders
 Thermoregulation
 Body Temperature
 Core temperature
 Peripheral temperature
 The Hypothalmus
 Heat Dissipation
 Sweating, vasodilation
 Heat Conservation
 Shivering,
vasoconstriction

7. Pathophysiology of Heat
and Cold Disorders
 Thermoreceptors
 Peripheral thermoreceptors
 Central thermoreceptors
 Metabolic Rate
 Basic metabolic rate
 Exertional metabolic rate
 Core temperature measurement

8. 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

9. 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

10. Heat Disorders
 Preventive Measures
 Maintain adequate fluid intake.
 Allow time for gradual acclimatization.
 Limit exposure to hot environments.

11. Heat Disorders

12. Heat Cramps

13. Heat Exhaustion

14. Heatstroke

15. 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

16. Fever (Pyrexia)
 Pyrogens
 Differentiating Fever from
Heatstroke
 Cooling the Fever Patient
 Consider antipyretic medication.
 Acetaminophen or ibuprofen
 Avoid sponge baths.

17. Cold Disorders
 Hypothermia
 Mechanisms of Heat Conservation
and Loss
 Predisposing Factors
 Age of the Patient
 Health of the Patient
 Medications
 Prolonged or Intense Exposure
 Coexisting Weather Conditions

18. 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
 Mild
 Severe
 Compensated Hypothermia
 Acute, Subacute, and Chronic Exposure

19. Cold
Disorders

20. Hypothermia
 Signs & Symptoms
 Mild
 Severe

21. Hypothermia
 ECG
 Pathognomonic J waves (Osborn waves).
 Eventual onset of bradycardia.
 Ventricular fibrillation probable below 86º F.

22. Hypothermia

23. Hypothermia
 Treatment
 Active Rewarming
 Active external rewarming
 Active internal rewarming
 Rewarming Shock
 Cold Diuresis

24. 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.

25. 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

26. 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.

27. 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.

28. 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.

29. Near-Drowning
and Drowning

30. Near-Drowning
and Drowning
 Factors Affecting Survival
 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.

31. 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.

32. 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

33. 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.

34. 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.

35. 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

36. 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

37. Diving Emergencies
 Factors to Assess
 Rate of Ascent
 Associated with panic forcing a rapid ascent
 Inexperience of the Diver
 Improper Functioning of Depth Gauge
 Previous Medical Diseases
 Old Injuries
 Previous Episodes of Decompression Illness
 Use of Alcohol or Medications

38. 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.

39. Pressure Disorders
 Treatment
 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.

40. 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.

41. 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.

42. 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.

43. 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.

44. Diving Emergencies
 Other Diving-Related
Emergencies
 Oxygen Toxicity
 Hypercapnia
 Diver’s Alert Network
 Consultation and Referrals
 (919) 684-8111

45. High-Altitude Illness
 Manifestation
 Altitudes above 8,000’
 Prevention
 Ascend gradually.
 Limit exertion.
 Descend for sleep.
 Eat a high-carbohydrate diet.
 Medications
 Acetazolamide and nifedipine

46. 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.

47. 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.

48. 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.

49. 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

50. Nuclear Radiation
 Ionizing Radiation
 Alpha particles
 Beta particles
 Gamma rays
 Neutrons
 Effects of Radiation on the Body
 Detection of Radiation
 RAD and REM
 Acute and Long-Term Effects

51. Nuclear Radiation

52. Nuclear Radiation
 Principles of
Safety
 Time
 Distance
 Shielding
 Clean Accidents
 Patient is exposed but
not contaminated.
 Dirty Accidents
 Patient is
contaminated by
radioactive particles,
liquids, gases ,or
smoke.

53. 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.

54. Environmental
Emergencies
 Pathophysiology of Heat and Cold
Disorders
 Heat Disorders
 Cold Disorders
 Near-Drowning and Drowning
 Diving Emergencies
 High-Altitude Illness
 Nuclear Radiation