BLS 2014: Environmental Emergencies

1. BLS 2014: Environmental Emergencies

2. Introduction • This course addresses: • Cold and heat related emergencies • Water emergencies • Stings & bites • Anaphylaxis and use of the epi-pen • Toxic gases • Electric shock and lightning strike

3. Objectives • Identify the ways the body produces and loses heat. • Identify signs, symptoms, and emergency care of heat-related emergencies. • Identify signs, symptoms, and emergency care of cold-related emergencies. • Identify signs, symptoms, and emergency care of water-related emergencies • Identify signs, symptoms, and emergency care of bites and stings • Identify signs, symptoms, and emergency care of anaphylaxis and severe allergic reaction • Identify signs, symptoms, and emergency care of bites and stings • Identify signs, symptoms, and emergency care of toxic gas exposure • Identify signs, symptoms, and emergency care of electric shock and lightning strike

4. Heat Production and Loss

5. Heat Production • Three ways body can produce heat: • Metabolism • Shivering • Exercise

6. Metabolism • Metabolism • Conversion of food to energy • Activity of bodily functions (such as circulation, respiration and muscle tone) • Some substances broken down to create energy while other substances are synthesized into tissue building material

7. Shivering • Rapid contraction & expansion of muscle tissues • Shivering can produce 40 times more heat than baseline metabolism

8. Exercise • Produce heat through exercise • Happens as long as there is activity, fuel (for instance, glucose or fat), oxygen and water

9. Factors That Affect Heat Production • Many factors affect how well body can produce heat: • Core temperature • Medical conditions • Body fluid status (dehydration) • Drugs and chemicals

10. Factors That Affect Heat Production Core Temperature • Colder body – less able it to produce adequate heat through metabolism • Hypothermia greatly reduces body’s ability to produce heat • Cooling slows chemistry of body Medical Conditions • Cardiac disease decreases ability to compensate for heat stress • Endocrine diseases such as thyroid, adrenal & insulin deficiencies may contribute to hypothermia • Strokes can cause immobility with reduced muscular activity Temperature control centers of brain may be damaged

11. Factors That Affect Heat Production Body Fluid Status • Metabolism is not as efficient when the body is dehydrated • Dehydration is a common problem in hot environments. Drugs and Chemicals • Beta-blockers decrease cardiac output & peripheral vascular control mechanisms • Effect works to lower body temperature • Drugs such as cocaine and amphetamines may contribute to hyperthermia (heatstroke) • Mimic stimulation of sympathetic nervous system

12. Heat Loss • Four heat loss mechanisms are: • Conduction • Convection • Radiation • Evaporation Under normal conditions, heat loss mechanisms are balanced with heat production mechanisms

13. Conduction • Transfer process – heat moves between two touching objects (From warmer object to colder object) • Motion of molecules bumping into one another spreads heat • Molecules bump around like billiard balls on a billiards table • Major source of heat loss in case of cold-water immersion • Water conducts heat 25 times more quickly than air

14. Convection • As air warms, rises & cooler air replaces it • Cool air then is warmed • Example – blow on your food to cool it • Transfer of heat between body & air or water that surrounds it • Occurs when a gas or liquid carries heat away • Body’s heat energy is lost more rapidly in moving air or water • Example – rising warm air from earth’s surface

15. Radiation • Warm body releases energy without direct contact • Heat energy travels by bumping molecules (as in conduction) • Also travel through electromagnetic waves • Sun is best known example of heat transfer through radiation

16. Evaporation • Conversion of a liquid to a gas • Heat pan of water, energy applied to water will cause to evaporate • Requires a lot of heat • Takes a lot of energy to break water molecules apart & convert liquid to gas • Human body takes advantage of evaporation’s heat loss powers by sweating

17. Heat Illness

18. Heat Cramps • Heat cramps or muscle cramps result from uneven distribution of body fluids & salts • Muscle cramps from this condition can be mild to severe, involving the extremities or the abdomen • Cramps can be accompanied by: • Dizziness • Weakness • Nausea

19. Heat Exhaustion • Named for feeling of exhaustion people experience • Result of excessive heat & dehydration • Reduce circulating blood volume & increase peripheral pooling due to vasodilation • Cooling mechanisms of radiation & evaporation become inefficient due to loss of fluids : • Clinical findings associated with heat exhaustion include: • Dizziness, weakness and nausea • Rapid, weak pulse • Cool, clammy skin • Profuse sweating • Altered LOC

20. Heatstroke • Life-threatening emergency – occurs when body's heat-regulating ability fails • Happens when body is subjected to more heat than it can deal with & four heat loss mechanisms overwhelmed • Clinical findings of heatstroke include: • Altered LOC (confusion, disorientation, or unconsciousness) • Rapid, bounding pulse • Rapid, deep respirations • Hot, dry, flushed skin* • Dilated pupils • Seizures * Can be damp if rapid onset

21. Emergency Care for Heat-Related Emergencies • Reduce core temperature: • Remove or loosen clothing • Provide a cool environment • Apply cool packs • Request paramedics when ALS indicators are present • provide oxygen and/or ventilatory assistance • Position patient appropriately • Monitor vital signs • Patient responsive & not nauseated, consider giving water

22. Cooling Strategies • Provide a Cool Environment • As soon as time allows, move patient to back of air-conditioned aid car with the air conditioner running on maximum • Fan patient aggressively if staffing allows • Keep skin wet by applying cool water with a sponge or wet towel

23. Cooling Strategies • Remove Clothing • Loosen or remove clothing to promote efficient convention • Consider applying water with a sponge or wet towels on patient’s skin • If you apply water to skin to encourage evaporation, use room temperature water • Do not induce shivering

24. Cooling Strategies • Apply Cold Packs • Neck, groin & armpits • Hospitals generally have tools necessary to properly lower core temperature • Do not delay transport • Notify hospital early to allow ED staff time to prepare

25. Cold Exposure

26. Hypothermia • Cooling of core temperature below 98.6°F • Caused by loss of body heat or decreased heat production • Exposure to a cool environment • Immobile elderly person lying on a floor • Drowning victim & who has been submerged Hypothermia can occur rapidly in wet environments

27. Hypothermia Early recognition increases chances of survival

28. Frostbite Superficial Injury - Clinical Findings • Blanching of skin • Loss of feeling & sensation in injured area • Tingling sensation if re-warmed Deep Injury - Clinical Findings • White, waxy skin • Swelling and/or blisters • Skin can appear flushed with areas of purple & blanching or mottled & cyanotic

29. Emergency Care for Cold-Related Emergencies • Pre-hospital emergency care for a hypothermic patient is as follows: • Remove patient from cold environment • Protect from heat loss • Provide high-flow oxygen

30. Emergency Care for Hypothermia • Remove from Cold/Protect from Heat Loss • Move patient to aid car warmed to 80°F • Keep patient flat • Remove wet clothing • May need to protect from heat loss by insulating patient with blankets • Provide High Flow Oxygen • Provide high flow oxygen via BVM for a non-breathing patient

31. Hypothermic Cardiac Arrest • Hypothermic patient in cardiac arrest or with profound bradycardia, following guidelines apply: • If no pulse detected after 1 minute, begin CPR & apply AED • If breathing, assume there is cerebral perfusion, therefore NO CPR • If AED analysis yields a “shock indicated” follow cardiac arrest protocol • If pulse is present withhold CPR regardless of rate or BP

32. Emergency Care for Frostbite • Protect affected area from further injury • Remove constricting or wet clothing & jewelry • Cover with dry bulky dressing • Splint affected extremity, prevent use of extremity

33. Transport Times Over Two Hours • Do not re-warm frozen tissue unless transport time will exceed 2 hours & you are certain the thawed tissue will not refreeze • Obtain medical direction prior to initiating re-warming • Re-warming should be done with 100 – 105°F water • Do not use dry heat—it heats unevenly and can burn frozen tissue • Stop re-warming when tissue turns red-purple & becomes pliable

34. Water Related

35. Drowning and Near Drowning • Several things you should determine: • Length of submersion • Temperature of water • Depth of water • Drowning – death caused by hypoxia following submersion in water • Near drowning – submersion in water that does not result in death • Without oxygen, hypotension, bradycardia & cardiac arrest ensue

36. Length of Submersion • Include length of submersion in report to hospital staff May have to estimate based on bystander testimony & other indicators • Submersion is short duration (2 minutes or less), a short period of CPR likely will result in successful resuscitation • Significant number of near-drowning patients who look fine initially develop pulmonary edema several hours later • Non-cardiac related condition is called acute respiratory distress syndrome (ARDS).

37. Water Temperature • Submersion times greater than 10 minutes make successful resuscitation unlikely • High survival rates for cold water drowning's are a myth – there are rare cases of successful resuscitations after long submersions, but most long submersions do not survive, or survive with devastating neurologic outcomes. • Contrary to popular belief, children do not have better neurologic outcomes than adults

38. Depth of Water • Spinal injuries seen in many water-related accidents • Diving into shallow water common mechanism for head & spinal injury & subsequent drowning • Potential for a spinal injury, stabilize cervical spine while in the water, if possible • Other conditions associated with drowning: • Skeletal & soft tissue injuries • Drug or alcohol intoxication • Underlying medical conditions

39. Emergency Care for Drowning/Near Drowning • Management requires prompt basic life support & following measures: • Safely remove victim from the water • Stabilize c-spine and place patient on a backboard* • Follow resuscitation protocols for cardiac or pulmonary arrest • Administer oxygen and/or ventilatory assistance • Place in a supine position to avoid cerebral edema • Prepare suction and expect vomiting • Warm up the aid unit • Monitor vital signs *If spine injury is suspected or patient is unresponsive. If possible, initiatestabilization during removal from water.

40. Diving Emergencies • Use of compressed air in an underwater environment can be hazardous • In addition to drowning, common diving-related hazards include air embolism and decompression illness

41. Air Embolism • Air embolism – presence of gas bubbles in bloodstream that obstruct circulation • Occurs during ascent when pressure in lungs forces air

42. Air Embolism Signs: • Apnea (no breathing) • Frothy fluid from nose or mouth • Loss of consciousness • Partial weakness or paralysis • Seizures • Irregular pulse • Death Symptoms: • Dizziness • Confusion • Chest pain • Diminished sensation in parts of the body • Visual blurring

43. Decompression Sickness • Nitrogen in blood forms bubbles due to rapid ascent • Bubbles collect in tissues & interfere with blood flow • Significant history for all diving emergencies includes: • Number of dives in past 24 hours • Depth of dive • Length of time underwater • Problems encountered while diving • Significant medical history (including meds)

44. Decompression Sickness • Dive usually at depth of at least 33 feet • Less likely at depths <33 feet • Still can happen • Longer & deeper the dive, more nitrogen dissolves in blood • Dehydration, exertion & air travel within 12 hours after diving all increase the probability of DCI • Symptoms of DCI vary widely depending on where bubbles collect • Joint pain, abdominal pain, neurological symptoms & difficulty urinating are common • Diver who complains of feeling ill after diving should be evaluated for DCI • Symptoms can appear within a few minutes of surfacing or it may take hours

45. Treatment for Diving Injuries Definitive treatment for any significant diving emergency is recompression in a hyperbaric facility! • Emergency care • ABCs • High flow 100% oxygen • Place the patient in a position of comfort (“head down, feet up” is no longer recommended) • Request ALS intervention as needed • Gather information on: • Maximum depth dived • Time on the bottom • Time since reaching surface • Whether the dive was single or multiple dives were done. • If the patient is to be flown by helicopter then advise the crew that this is a decompression accident. This prepares the crew for low fly or cabin pressure alterations during flight.

46. Bites and Stings

47. Bites and stings • Animals of all types from dogs to bees may bite or sting to defend themselves or their young. Bites and stings can cause problems ranging from local tissue damage to systemic symptoms.

48. Mammal Bites and Scratches • Local tissue damage • Bleeding (can be significant depending on the size of the animal and patient, and location of the wound) • Puncture wounds increase the risk of infection • Remote risk of rabies (viral disease transmitted by saliva of infected mammals) • Emergency care • ABCs • Control bleeding, sterile dressing • Identify the animal (contain if possible) • Evaluation at ER or clinic for possible antibiotics

49. Snake Bites • Snakes bite if threatened or to obtain food (typically small mammals) • Only a small percentage of snakes in the US are poisonous • Even poisonous snakes often bite without envenomation • Sometimes people keep poisonous snakes as pets • Alcohol use is a significant factor in many snakebites • Signs and symptoms range from local tissue damage to systemic effects, and vary depending on the type of snake • Zoos are excellent sources of information about snakebites and often stock antivenom

50. Snake Bites Emergency care • Non-poisonous snake: wound care • Poisonous snake: • ABCs • Request ALS if indicated • Constricting bands, suction of bite are no longer recommended • Remove jewelry from affected limb before swelling begins, if possible • Bandage and immobilize site of injury