Environmental Emergencies

Environmental Emergencies Chapter 24

Discuss heat and cold emergencies Discuss Hypothermia What are Local Cold injuries Discuss Hyperthermia Discuss Bites and stings Talk about how to deal with lightning strikes What to do about Acute altitude sicknesses Objectives

Hypothalamus – monitors and controls the hypothalamus in the brain (98.6°F or 37°C) Thermoregulatory center in the hypothalamus receives input from central thermoreceptors and peripheral thermoreceptors Thermoreceptors – responsible for sending nerve impulses to the hypothalamus indicating the temperature of the body Central thermoreceptors Peripheral thermoreceptors Regulation of Temperature

When Heat Lost exceeds Heat Gained • Thermal gradient operates by warmer temperatures moving toward cooler temperatures • Body must maintain optimum body temperature • Body produces heat through metabolism and shivering • Body conserves heat by constricting blood vessels, sending warm blood from the surface of the skin to internal organs, pilorection, allowing little or no perspiration, decreasing the surface area

Skin – Increasing flow of warm blood near skin to dissipate excess heat; sweat Cardiovascular system – elevates heart rate, increasing contraction strength, more blood moves to the surface Respiratory system – eliminating heat through evaporation during exhalation When heat lost exceeds heat gained; Hypothermia = below 95°F Organs responsible for cooling

The Five Mechanisms • Radiation • Convection • Conduction • Evaporation • Respiration

Hyperthermia occurs when heat gained exceeds heat lost Body may produce more heat than is needed or may fail to cool the body when needed Hyperthermia is most common in situations where the air temperature is high, humidity is high, and there is little or no breeze When Heat Gained Exceeds Heat Lost

Results from an increase in the body’s heat loss, a decrease in the body’s heat production or both Most life-threatening cold injury because it affects the entire body ( mortality as high as 87%) Can have sudden or gradual onset Generalized Hypothermia

Pathophysiology of Generalized Hypothermia

Predisposing Factors • Ambient temperature, wind chill, moisture • Age • Medical conditions • Alcohol, drugs, poisons • Duration of exposure • Clothing • Activity level

Stages of Hypothermia • Can occur with little warning, progress rapidly • Initial reactions to cold exposure are increase in basal metabolic rate, muscular shivering and “Goosebumps” • Core temperature drops, body’s thermal-regulating mechanism and perception become confused

Immersion Hypothermia • Result of the lowering of the body temperature from immersion in cool or cold water • Should be considered in all cases of accidental immersion • Body temperature drops 25 – 30 times faster in water than in air of same temperature • Get patient out of water rapidly and out wet clothing into warm environment

Occurs in individuals who have a predisposition, disability, illness, or medication that renders them more susceptible to hypothermia (young/old) External category Internal category Remember a patient can be hypothermic even on a warm day if in air-conditioned environment with decreased tissue insulation and inability to move from a cold surface Urban Hypothermia

Hypothyroidism makes patient more susceptible to hypothermia Hypothyroidism – clinical syndrome characterized by an absence or severe deficiency of hormone secreted by thyroid A complication that occurs late in progression of hypothyroidism and can be fatal (core temp. 75 - 90°, seizures, slow reflexes, respiratory depression) Precipitating factors: exposure to cold, recent illness/infection, trauma, use of drugs that depress CNS Support lost functions: ABC’s Contact Med Control regarding rewarming techniques Myxedema Coma

Commonly called “frostbite” results from freezing of body tissue Requires much colder temperatures than does generalized hypothermia Often accompanies generalized hypothermia Local Cold Injury

Ice crystals form between cells of skin and expand as they extract fluid from cells Circulation is obstructed Injuries tend to occur on hands, feet, ears, nose, and cheeks Pathophysiology of Local Cold Injury

Any kind of trauma Extremes of age Tight/tightly laced footwear Use of alcohol during exposure to cold Wet clothing High altitudes Loss of blood Arteriosclerosis Predisposing Factors

Stages of Local Cold Injury • Early or superficial; • Involves tips of ears, nose, cheekbones, tips of toes or fingers, chin • Patient usually unaware of injury • Will lose feeling and sensation in affected area • Skin may begin to turn waxy gray or yellow • Skin remains soft, but cold to touch • If affected area rewarmed, patient will usually report tingling as area thaws

Late or Deep Cold Injury • Involves skin and tissue beneath • Skin is white and waxy • Palpation reveals firm to solid, frozen feeling • May involve whole hand/foot • Swelling and blisters may be present • As area thaws, may become blotchy or mottled • An extreme emergency, can result in permanent tissue loss

Scene Size-up Ensure your safety and crew Remember cold temperatures and high winds pose hazards for crew Be prepared for cold exposure Cold weather conditions exacerbate unstable environments Assessment-based Approach:Cold-Related Emergency

Is patient protected from cold? Ambient temperature cool or cold? Possibility of urban hypothermia, even though nature of call was something different? Is the wind blowing? Does it look like patient has been outside for a long time? Is patients clothing wet? Is patient dressed right for the environment? Inside temperature? Alcohol? Drugs? Any injuries that may interfere with normal thermoregulation such as spine or head injuries? Look for signs on interaction with environment

General impression Assess airway; open manually if needed Decrease in carbon monoxide production as the core temperature decreases may cause the respiratory rate and tidal volume to decrease and become ineffective Oxygen, warmed and humidified via NRB @ 15 lpm Inadequate breathing: PPV with supplemental oxygen: consider airway adjunct if needed Carefully check carotid and radial pulses, begin chest compressions if absent Skin: red in early hypothermia, then pale, to cyanotic, to gray Remove patient from environment, remove wet clothing, dry patient and wrap in warm blankets Primary Assessment

In back of warm ambulance Responsive: gather history and SAMPLE MOI: consistent with trauma suspected, perform physical exam Feel abdomen to get idea of how cold patient is Look for signs of cold injuries Baseline vitals: can reveal how far hypothermic patient is Changing vital signs: respiratory/pulse changes, skin color worsens, slowly responding pupils, low to absent BP Secondary Assessment

Signs/Symptoms – Local Cold Injury • Early: Blanching of skin, loss of feeling and sensation, continued softness of skin in injured area, tingling during rewarming • Late/deep: White, waxy skin, firm-to-frozen feeling when palpated, swelling, blisters, purple and blanching areas or mottled and cyanotic if skin is partially/wholly thawed

General: prevent further heat loss, rewarming quickly and safely, watch for complications Top priority: remove patient from cold environment Handle patient gently Oxygen via NRB @ 15 lpm; warmed/humidified Cardiac arrest: One shock from AED or has been at least 4 -5 minutes since patient arrested CPR for 2 minutes prior to analysis Watch for any sign of movement from unresponsive patient; do not start CPR Emergency Care

Active Rewarming • Follow Med Control, if appropriate • Wrap patient in warm blankets, heat pack or hot water bottles in groin, armpits, on chest, turn up heat in ambulance • Heat should be added gradually; never immerse patient in a tub of hot water or hot shower

Unresponsive or not responding properly • Do not actively rewarm; use only passive rewarming • Take measures to prevent further heat loss and give patients body optimum chance to rewarm itself • All hypothermic patients should receive passive rewarming • Do not allow eating or drinking stimulants • Never rub or massage • Transport quickly

Have patient make the least effort possible to stay afloat Lift patient from water in horizontal or supine position; prevents vascular collapse Gently remove wet clothing Treat as generalized hypothermia patient Emergency Care for Immersion Hypothermia

Remove from cold environment Never initiate thawing if there is danger of re-freezing Oxygen via NRB @ 15 lpm Prevent further injury Early/superficial; Remove jewelry, wet/restrictive clothing Immobilize affected extremity and elevate Cover skin with dressing or dry clothing to prevent friction Never rub or massage Never re-expose injured skin to cold Emergency care: Local Cold Injury

Emergency Care for Local Cold InjuryLate/Deep injury • Remove jewelry, wet/restrictive clothing • Leave in place frozen clothing • Cover affected skin with dressings or dry clothing • Do not break blisters or treat with salve/ointment • Do not rub or massage • Never apply heat or rewarm skin • Do not allow patient to walk on injured extremity

Rewarm rapidly after contacting Med Control Immerse in warm-water bath (104°) Monitor water to stay at even temperature Continuously stir water to keep even temperature Keep tissue in warm water until soft, color/sensation returns After thawing, dress area with sterile dressings Elevate extremity Protect against re-freezing Transport asap Emergency Care for Local Cold Injury

Brought on by an increase in body’s heat production or inability to eliminate the heat produced Most emergencies occur in early summer season before people have acclimated themselves to the season’s hight temperatures Hyperthermia

Heat cramps Least serious form Muscle spasms or cramps Affects large flexor muscle groups of the body first; abdominal muscles, gluteus, hamstrings Pathophysiology of Heat-related Emergencies

Disturbance in body’s blood flow, resulting in mild state of shock Large quantities of salt and water are lost due to prolonged and profuse sweating, leading to diminished blood circulation Skin will be normal to cool in temperature, pale or ashen gray in color, and sweaty Occurs when the body has maximized the heat-dissipating mechanisms to a point where other body systems are starting to dysfunction Heat Exhaustion

Life-threatening emergency Body’s heat regulating mechanisms break down and become unable to cool the body Body becomes overheated, temperature rises, sweating ceases Brain cells are damaged Commonly unresponsive; skin hot and red Patient does not suffer from heat cramps/exhaustion first to suffer heat stroke Heat Stroke

Nonexertional heatstroke (NEHS) – occurs to elderly with sedentary lifestyles, chronically ill, on medications inhibiting temperature-sensing ability, live in regions of country that rarely experiences heat waves Exertional heatstroke (EHS) – occurs in younger people who are engaged in strenuous physical exertion in a very hot environment for prolonged periods Heat Stroke

Predisposing Factors • Climate • Exercise/strenuous activity • Age • Preexisting illnesses – heart or kidney disease, cerebrovascular disease, Parkinson's, thyroid gland disorder, skin diseases, dehydration, fatigue, obesity, mental retardation • Some medications/drugs • Lack of acclimation

Assessment-based Approach:Heat-Related Emergencies Scene Size-up • Scan for evidence of heat-related emergency; ambient temperature/humidity, exercise/activity, clothing, infants/children in closed structures, medications or drugs • Recognize your own limitations for heat exposure

Is patient dressed for the environment? Assess mental status Assess airway/breathing; provide oxygen therapy Assess pulse; weak/rapid radial or absent due to dehydration Altered mental status with hot skin should be considered priority patient Primary Assessment

Move patient to cooler environment Responsive; OPQRST history Physical exam; target complaint areas Baseline vitals – hot skin is alarming Unresponsive: physical exam, vital signs, history from family/bystanders Secondary Assessment

Signs/Symptoms of Generalized Hyperthermia • Elevated core temperature • Muscle cramps • Weakness/fainting • Rapid pulse; strong first, becoming weak • Initial deep, rapid breathing; becomes shallow/weak • Headache • Seizures • Loss of appetite, nausea, vomiting • Altered mental status to unresponsiveness • Moist, pale skin with normal-cool temperature or hot dry/moist

Emergency Care: Patient with Moist, pale, Normal-to-cool skin • Move patient to cool place • Oxygen via NRB @ 15 lpm • Remove or loosen clothing • Place in supine position • Responsive, without nausea: have patient drink • Unresponsive/altered/vomiting: Do not give fluids • Transport when: unresponsive or altered mentally, vomiting or nauseated, core temp. @ 101°, continuously rising temp., does not respond to care

Emergency Care: Patients with Hot Skin that is Moist or Dry • Remove to cool ambulance • Remove clothing • Oxygen via NRB @ 15lpm • Begin cooling patient • Pour tepid water over patient, avoid cold • Cold packs; groin, each side of neck, armpits, behind each knee • Fan aggressively or electric fan • Keep skin wet • Be prepared for seizures or suctioning • Transport ASAP

Remove to cool environment Contact Med Control regarding sips of water or low-concentration of salt water every 15 minutes (Gatorade) Apply moist towels to forehead and cramping muscles Talk to patient to avoid recurrence Reassessment: Reassess mental status, ABC’s, vital signs, treatment. Prepare to establish airway, oxygen therapy, if breathing becomes inadequate, assess pulse and mentation to confirm improvement, record, and report vital signs every 5 minutes Emergency Care: Heat cramps

Bites and Stings - Snakebite • Non-poisonous: treated as minor wounds • Poisonous snakes: coral snakes and pit vipers (rattlesnakes, copperheads, water moccasins) bites are considered emergency • Characteristics: Large fangs (except coral snakes) Elliptical pupils/vertical slits, pit between eye and mouth, variety of blotches on backgrounds of pink, yellow, olive, tan, gray or brown skin (coral ringed in red, yellow, black)

Snakebite – signs/symptoms • Pit vipers occur immediately, coral snakes delayed at least 1 hour up to 8 hours • Determining severity: location of bite since fatty tissue absorbs more slowly, pathogens in venom, patient size/weight, general health and condition, physical activity after bite • Emergency care is same for all bites and stings

Emergency care only if itching last longer than 2 days, signs of infection, or allergic reaction, the insect is poisonous Redness, tenderness, swelling at/around sting site, with absence of other symptoms, considered local reaction Treat with cold compresses Allergic reactions may cause Anaphylaxis Insect Bites and Stings

Shiny black body, thin legs, crimson red marking on abdomen, shape of an hourglass or two triangles Highest risk: children under 16, people over 60, people with chronic illness, hypertension patient Signs/Symptoms: Pinprick sensation at bite site, becoming dull ache within 30 minutes Severe muscle spasms, especially shoulder, back, chest abdomen Rigid, boardlike abdomen Dizziness, nausea, vomiting, respiratory distress (severe cases) Emergency Care: Provide general wound care and transport Black Widow Spider

Environmental Emergencies