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Heat and Cold Emergencies

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Cramps of fingers, arms, legs, abdominal muscles. Nausea ... Supine, legs elevated. Sponge with cool water, fan. Balanced salt/water solution, or ... – PowerPoint PPT presentation

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Title: Heat and Cold Emergencies


1
Heat and Cold Emergencies
2
Thermoregulation
  • Homeostasis requires stable temperature
  • 98.6ºF

3
Thermoregulation
  • Control mechanism
  • Hypothalamus
  • Peripheral thermoreceptors
  • Balance between heat production, heat loss

4
Heat Production
  • Metabolism
  • Voluntary large muscle movement
  • Shivering

5
Heat Loss
  • Conduction
  • Convection
  • Radiation
  • Evaporation
  • Skin
  • Respiratory tract

6
Heat ProductionHeat Loss
  • Increased Body Temperature

7
Heat Loss Heat Production
  • Decreased Body Temperature

8
Heat and Cold Induced Illness
  • Results from
  • Increase or decrease in body temperature outside
    normal range
  • Prolonged efforts to compensate

9
Hyperthermia
  • Caused by
  • Overwhelmed thermoregulatory system
  • Environmental conditions (exogenous)
  • Excessive exercise (endogenous)
  • Drugs
  • Excessive clothing
  • Failure of thermoregulatory system
  • Geriatric patients
  • CVA

10
Heat-Related Illness
  • Increased temperature
  • Cutaneous blood vessel dilation increased
    radiant, conductive heat loss
  • Sweating
    increased evaporative heat loss

11
Heat Cramps
  • Pathophysiology
  • Hot environment causes profuse sweating
  • Na lost in sweat
  • Lack of Na causes muscle cramping

12
Heat Cramps
  • Signs/Symptoms
  • Patient usually in good condition working in
    hot, humid environment
  • Cramps of fingers, arms, legs, abdominal muscles
  • Nausea
  • Normotensive, mild hypotension tachycardia
  • Cool, pale skin
  • Awake, alert, normal body temperature

13
Heat Cramps
  • Management
  • Move to cool place, rest, lie down
  • Give balanced salt/water solution
  • Salt alone leads to increased nausea, increased
    water loss
  • Water alone leads to worsened cramping
    (dilutional hyponatremia)

14
Heat Cramps
  • Management
  • IV NS, LR if patient too nauseated to drink
  • Avoid massaging muscles
  • Avoid activity
  • Increase fluid, salt intake

15
Heat Exhaustion
  • Pathophysiology
  • Increased vascular space due to vasodilation
  • Decreased blood volume due to sweating
  • Decreased CNS perfusion

16
Heat Exhaustion
  • Epidemiology
  • People working in hot, humid environments
  • Elderly, due to decreased thirst mechanism
  • Hypertensives, due to medication effects

17
Heat Exhaustion
  • Signs/Symptoms
  • Headache, dizziness, fatigue, nausea, confusion
  • Weakness, syncope
  • Profuse perspiration, pallor
  • Tachycardia, hypotension, tachypnea
  • Orthostatic changes
  • Normal core temperature

18
Heat Exhaustion
  • Management
  • Move to cool place, stop activity, lie down
  • Supine, legs elevated
  • Sponge with cool water, fan
  • Balanced salt/water solution, or
  • IV with NS, LR if too nauseated to drink
  • Assess glucose if altered mental status

19
Heat Exhaustion
  • Management
  • Transport indicated if
  • Loss of consciousness occurs
  • Underlying cardiovascular disease
  • Oxygen, EKG monitor if transport indicated

20
Heat Stroke
  • Pathophysiology
  • Body heat accumulation leads to increased
    temperature above 1060F
  • Increased temperature damages hypothalamus
  • Heat regulating mechanism failure occurs
  • 25 - 50 mortality

21
Types of Heat Stroke
  • Exertional Heat Stroke
  • Occurs in healthy, young people in hot
    environments
  • Heat builds up faster than it is removed
  • Damage to hypothalamus occurs
  • Patient sweats heavily

22
Types of Heat Stroke
  • Classic Heat Stroke
  • Elderly, alcoholics, obese, heart disease
    patients, phenothiazine users
  • Body heat builds up slowly over several days
  • Dry skin, absence of sweating

23
Heat Stroke
  • Signs/Symptoms
  • Headache, dizziness, irritability
  • Decreased LOC, seizures
  • Bounding pulse progressing to rapid, weak pulse
  • Hypotension secondary to vasodilation

Presence, absence of sweating NOT reliable
24
Heat Stroke
Altered LOC Hot Environment ? Heat
Stroke
25
Heat Stroke
  • Management
  • Secure airway
  • High concentration oxygen
  • Rapid cooling to 1020F
  • IV with NS, LR
  • Avoid volume in classic heat stroke
  • Exertional heat stroke may need volume
    replacement
  • Monitor EKG

26
Heat Stroke
  • Management
  • Drugs as necessary
  • Glucose for hypoglycemia
  • Diazepam for seizures/sedation
  • Reassess for secondary complications
  • Cardiac dysrhythmias
  • Pulmonary edema
  • Transport

27
Cold-Related Illness
  • Local cold injury
  • Generalized cooling

28
Local Cold Injury
  • Nonfreezing
  • Chilblains
  • Trench foot
  • Freezing
  • Frostnip
  • Frostbite

29
Chilblains
  • Caused by chronic exposure to damp, nonfreezing
    ambient temperatures
  • Painful, inflammatory lesions on skin
  • Hands, ears, lower legs, feet common sites
  • Pruritus, burning, paresthesias
  • Tends to recur
  • Rewarm, bandage, elevate

30
Trench Foot
  • Caused by prolonged skin exposure to cool, wet
    conditions
  • Skin becomes pale, mottled, anesthetic
  • Sloughing, gangrene may occur
  • Clean, warm, dry bandages elevation

31
Frostnip/Frostbite
  • Local freezing of tissue
  • Commonly affected areas
  • Toes, feet
  • Hands, fingers
  • Nose
  • Ears

32
Frostnip/Frostbite
  • Risk Factors
  • Poor clothing
  • Poor nutrition
  • Diabetes
  • Decreased tissue perfusion
  • Tobacco, tight clothing
  • Vasodilation
  • EtOH, medications

33
Frostnip/Frostbite
  • Pathophysiology Phase I
  • Exposure to cold
  • Vasoconstriction
  • Decreased blood flow to periphery
  • Ice crystal formation in extracellular space,
    ischemia
  • Cellular dehydration, hyperosmolarity

34
Frostnip/Frostbite
  • Pathophysiology Phase I
  • Edema
  • Increased pressure, blood vessel damage
  • Worsened ischemia
  • Destruction of cellular components

35
Frostnip/Frostbite
  • Pathophysiology Phase II
  • Tissue is rewarmed
  • Blood flow returns
  • Damaged capillaries leak fluid
  • Swelling occurs
  • Sludging of blood, thrombus formation occurs

36
Frostnip
  • Extremity appears pale, discomfort present
  • No extracellular ice crystal formation
  • Symptoms resolve on rewarming
  • Tissue loss does not occur

37
Frostbite
  • Extent of injury frequently cannot be determined
    until rewarming occurs

38
Frostbite
  • Signs/Symptoms
  • 1st degree
  • Partial skin freezing redness, mild edema lack
    of blisters
  • 2nd degree
  • Full thickness freezing substantial edema,
    formation of clear blisters

39
Frostbite
  • Signs/Symptoms
  • 3rd degree
  • Full-thickness skin and subcutaneous freezing
    hemorrhagic blisters, skin necrosis, bluish-gray
    discoloration
  • 4th degree
  • Full-thickness damage affecting muscles, tendons,
    bones little edema, initially mottled or
    cyanotic, eventually dry, black, mummified

40
Frostbite
41
Frostbite
42
Frostbite
  • Management Short transport
  • ABCs
  • Protect affected area
  • Bandage
  • Avoid rewarming, thawing
  • Prevent, treat hypothermia
  • Remove wet or constrictive clothing
  • Dry patient
  • Warm IV fluids
  • Minimal analgesics (NSAIDS) for pain

43
Frostbite
  • Management Long transport
  • Remove patient from cold
  • Remove clothing from affected area
  • Rewarm in water 100 - 1050F until
    flushing/tingling present
  • Dry gently, bandage
  • Treat concurrent hypothermia
  • Analgesia for pain

44
Frostbite
  • Do NOT
  • Allow refreezing
  • Massage injured part
  • Allow patient to smoke
  • Puncture or drain blebs

45
Hypothermia
  • Core Temp
  • May be caused by
  • Decreased heat production
  • Excess heat loss
  • Various associated factors
  • Environment (temperature, wet vs. dry)
  • Energy (food, water)
  • Ambulatory ability

46
Hypothermia
  • Risk factors
  • Extremes of age
  • Those outdoors
  • Hypothyroidism
  • Diabetes, hypoglycemia
  • Alcohol, depressant drug abuse
  • Poor nutrition

47
Hypothermia
  • Pathophysiology
  • Immediate vasoconstriction
  • Catecholamine release
  • Increased HR, RR, BP
  • Shivering until
  • glucose depleted
  • temperature below 90oF
  • Shivering stops ? rapid cooling
  • Eventual ? in RR, HR, BP
  • Cardiac Arrest

48
Hypothermia
  • Pathophysiology
  • Left shift of oxyhemoglobin dissociation curve
  • Decreased oxygen release to tissues
  • Depression of insulin release, effectiveness
  • Hyperglycemia
  • Depression of ADH release
  • Increased urine output, cold diuresis

49
Hypothermia
  • Signs/Symptoms
  • Pallor, shivering
  • Ataxic gait
  • Apathy, drowsiness, coma
  • Slowing pulse rate, respirations
  • Cardiac arrest
  • Altered LOC Cool Environment ? Hypothermia

50
Hypothermia
Altered LOC Cool Environment ? Hypothermia
51
Hypothermia
  • ECG changes (mostly late)
  • Bradycardia (possibly unresponsive to atropine)
  • Small, absent P wave
  • Abnormal ST segments, T waves
  • J (Osborn) wave

52
Hypothermia
  • J waves

53
Hypothermia
  • Management
  • Mild core temperature 90-95oF
  • Moderate core temperature 86-89oF
  • Severe core temperature

54
Hypothermia
  • Management Mild Hypothermia
  • Handle gently
  • Prevent further heat loss
  • Insulate from cold
  • Add heat to head, neck, chest, groin
  • Warm oral fluids after uncontrolled shivering
    stops

55
Hypothermia
  • Management Moderate Hypothermia
  • Prevent further heat loss
  • Remove wet clothing
  • Cover with blankets
  • Avoid active rewarming
  • IV with NS
  • EKG

56
Hypothermia
  • Management Severe Hypothermia
  • Secure airway/assist ventilations
  • Do NOT hyperventilate
  • Avoid rough handling
  • Prevent further heat loss
  • Remove wet clothing
  • Cover with blankets
  • EKG, IV with NS
  • Internal rewarming only

57
Hypothermia
  • Hypothermic Cardiac Arrest
  • Limit 3 shocks
  • No medications
  • 86 ºF
  • ? drug dosing intervals
  • Repeat shocks as core temp rises

58
Hypothermia
  • Hypothermic Cardiac Arrest
  • Resuscitate aggressively
  • Little consideration given to terminating
    resuscitation efforts

Youre not dead until youre warm and dead
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