Environmental Emergencies

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